The RFad Method--a new fatigue recovery time assessment for industrial activities.

PubMed

Silva e Santos, Marcello; Vidal, Mario Cesar Rodriguez; Moreira, Sergio Bastos

2012-01-01

This paper presents a study about fatigue recovery time assessment processes in work activities. It came about due to a demand presented by an automotive industry giant, in need of updating existing cycle time sheets and TAKT time parameters. The company decided to hire an Ergonomics Laboratory with ties to a major Brazilian University in order to evaluate current conditions and establish a new method to either calculate recovery times or validate existing assessment criteria, based in the ergonomics evaluation of the work activities. It is clear that there has been evident evolution in the industrial sector in the past two decades. It brought up fast modernization of industrial processes, not only in production but also in terms of management systems. Due to improved computer and robotics systems, combined with overall operational advancements - like the use of lighter hand tools and more effective hoist systems - most work activities have had its physical effort requirements reduced in the past decades. Thus, compensation factors built into production times need to be reviewed in order to avoid unnecessary costs associated to them. By using ergonomics considerations, we prevent simply removing the physical variables built in rest time calculations without taking on account, for example, additional cognitive load represented by the use of more sophisticated pieces of equipment.

Clock Synchronization Through Time-Variant Underwater Acoustic Channels

DTIC Science & Technology

2012-09-01

stage, we analyze a series of chirp responses to identify the least time -varying multipath present in the channel between the two nodes. Based on the... based on the detected arrivals and determines the most stable one based on the correlation coefficient of a model fit to the time -of-arrival estimates...short periods of time . Nevertheless, signal fluctuations can occur due to transceiver motion or inherent changes within the propagation medium

Polar motion excitation analysis due to global continental water redistribution

NASA Astrophysics Data System (ADS)

Fernandez, L.; Schuh, H.

2006-10-01

We present the results obtained when studying the hydrological excitation of the Earth‘s wobble due to global redistribution of continental water storage. This work was performed in two steps. First, we computed the hydrological angular momentum (HAM) time series based on the global hydrological model LaD (Land Dynamics model) for the period 1980 till 2004. Then, we compared the effectiveness of this excitation by analysing the residuals of the geodetic time series after removing atmospheric and oceanic contributions with the respective hydrological ones. The emphasis was put on low frequency variations. We also present a comparison of HAM time series from LaD with respect to that one from a global model based on the assimilated soil moisture and snow accumulation data from NCEP/NCAR (The National Center for Environmental Prediction/The National Center for Atmospheric Research) reanalysis. Finally, we evaluate the performance of LaD model in closing the polar motion budget at seasonal periods in comparison with the NCEP and the Land Data Assimilation System (LDAS) models.

Nonlinear Analysis of a Bolted Marine Riser Connector Using NASTRAN Substructuring

NASA Technical Reports Server (NTRS)

Fox, G. L.

1984-01-01

Results of an investigation of the behavior of a bolted, flange type marine riser connector is reported. The method used to account for the nonlinear effect of connector separation due to bolt preload and axial tension load is described. The automated multilevel substructing capability of COSMIC/NASTRAN was employed at considerable savings in computer run time. Simplified formulas for computer resources, i.e., computer run times for modules SDCOMP, FBS, and MPYAD, as well as disk storage space, are presented. Actual run time data on a VAX-11/780 is compared with the formulas presented.

Effective utility accommodation : final report.

DOT National Transportation Integrated Search

2009-12-08

The report presents research regarding methods to improve project delivery times and minimize construction delays due to utility coordination by conducting a study of the current best practices used by six (6) similar state transportation departments...

A Stochastic Spiking Neural Network for Virtual Screening.

PubMed

Morro, A; Canals, V; Oliver, A; Alomar, M L; Galan-Prado, F; Ballester, P J; Rossello, J L

2018-04-01

Virtual screening (VS) has become a key computational tool in early drug design and screening performance is of high relevance due to the large volume of data that must be processed to identify molecules with the sought activity-related pattern. At the same time, the hardware implementations of spiking neural networks (SNNs) arise as an emerging computing technique that can be applied to parallelize processes that normally present a high cost in terms of computing time and power. Consequently, SNN represents an attractive alternative to perform time-consuming processing tasks, such as VS. In this brief, we present a smart stochastic spiking neural architecture that implements the ultrafast shape recognition (USR) algorithm achieving two order of magnitude of speed improvement with respect to USR software implementations. The neural system is implemented in hardware using field-programmable gate arrays allowing a highly parallelized USR implementation. The results show that, due to the high parallelization of the system, millions of compounds can be checked in reasonable times. From these results, we can state that the proposed architecture arises as a feasible methodology to efficiently enhance time-consuming data-mining processes such as 3-D molecular similarity search.

Degradation modeling of high temperature proton exchange membrane fuel cells using dual time scale simulation

NASA Astrophysics Data System (ADS)

Pohl, E.; Maximini, M.; Bauschulte, A.; vom Schloß, J.; Hermanns, R. T. E.

2015-02-01

HT-PEM fuel cells suffer from performance losses due to degradation effects. Therefore, the durability of HT-PEM is currently an important factor of research and development. In this paper a novel approach is presented for an integrated short term and long term simulation of HT-PEM accelerated lifetime testing. The physical phenomena of short term and long term effects are commonly modeled separately due to the different time scales. However, in accelerated lifetime testing, long term degradation effects have a crucial impact on the short term dynamics. Our approach addresses this problem by applying a novel method for dual time scale simulation. A transient system simulation is performed for an open voltage cycle test on a HT-PEM fuel cell for a physical time of 35 days. The analysis describes the system dynamics by numerical electrochemical impedance spectroscopy. Furthermore, a performance assessment is performed in order to demonstrate the efficiency of the approach. The presented approach reduces the simulation time by approximately 73% compared to conventional simulation approach without losing too much accuracy. The approach promises a comprehensive perspective considering short term dynamic behavior and long term degradation effects.

Cardiac arrest due to lymphocytic colitis: a case report

PubMed Central

2012-01-01

Introduction We present a case of cardiac arrest due to hypokalemia caused by lymphocytic colitis. Case presentation A 69-year-old Caucasian man presented four months prior to a cardiac arrest with watery diarrhea and was diagnosed with lymphocytic colitis. Our patient experienced a witnessed cardiac arrest at his general practitioner's surgery. Two physicians and the emergency medical services resuscitated our patient for one hour and four minutes before arriving at our university hospital. Our patient was defibrillated 16 times due to the recurrence of ventricular tachyarrhythmias. An arterial blood sample revealed a potassium level of 2.0 mmol/L (reference range: 3.5 to 4.6 mmol/L) and pH 6.86 (reference range: pH 7.37 to 7.45). As the potassium level was corrected, the propensity for ventricular tachyarrhythmias ceased. Our patient recovered from his cardiac arrest without any neurological deficit. Further tests and examinations revealed no other reason for the cardiac arrest. Conclusion Diarrhea can cause life-threatening situations due to the excretion of potassium, ultimately causing cardiac arrest due to hypokalemia. Physicians treating patients with severe diarrhea should consider monitoring their electrolyte levels. PMID:22405093

The long term financial impacts of CVD: living standards in retirement.

PubMed

Schofield, Deborah; Kelly, Simon; Shrestha, Rupendra; Passey, Megan; Callander, Emily; Percival, Richard

2012-03-22

Cardiovascular disease (CVD) has significant economic costs, however these are generally estimated for the present-time and little consideration is given to the long term economic consequences. This study estimates the value of savings those who retire early due to CVD will have accumulated by the time they reach the traditional retirement age of 65 years, and how much lower the value of these savings are compared to those who remained healthy and in the workforce. Using Health&WealthMOD - a microsimulation model of Australians aged 45 to 64 years, regression models were used to analyse the differences between the projected savings and the retirement incomes of people by the time they reach age 65 for those currently working with no chronic condition, and people not in the labour force due to CVD. Over 99% of individuals who are employed full-time will have accumulated some savings at age 65; whereas only 77% of those who are out of the labour force due to CVD will have done so. Those who retire early due to CVD will have a median value of total savings by the time they are 65 of $1833. This is far lower than the expected median value of savings for those who remained in the labour force full-time, who will have $281841 of savings. Not only will early retirement due to cardiovascular disease limit the immediate income and wealth available to individuals, but also reduce their long term financial capacity by reducing their savings. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Picosecond timing resolution detection of ggr-photons utilizing microchannel-plate detectors: experimental tests of quantum nonlocality and photon localization

NASA Astrophysics Data System (ADS)

Irby, Victor D.

2004-09-01

The concept and subsequent experimental verification of the proportionality between pulse amplitude and detector transit time for microchannel-plate detectors is presented. This discovery has led to considerable improvement in the overall timing resolution for detection of high-energy ggr-photons. Utilizing a 22Na positron source, a full width half maximum (FWHM) timing resolution of 138 ps has been achieved. This FWHM includes detector transit-time spread for both chevron-stack-type detectors, timing spread due to uncertainties in annihilation location, all electronic uncertainty and any remaining quantum mechanical uncertainty. The first measurement of the minimum quantum uncertainty in the time interval between detection of the two annihilation photons is reported. The experimental results give strong evidence against instantaneous spatial localization of ggr-photons due to measurement-induced nonlocal quantum wavefunction collapse. The experimental results are also the first that imply momentum is conserved only after the quantum uncertainty in time has elapsed (Yukawa H 1935 Proc. Phys. Math. Soc. Japan 17 48).

Ultrafast detection in particle physics and positron emission tomography using SiPMs

NASA Astrophysics Data System (ADS)

Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

2017-12-01

Silicon photomultiplier (SiPM) photodetectors perform well in many particle and medical physics applications, especially where good efficiency, insensitivity to magnetic field and precise timing are required. In Cherenkov time-of-flight positron emission tomography the requirements for photodetector performance are especially high. On average only a couple of photons are available for detection and the best possible timing resolution is needed. Using SiPMs as photodetectors enables good detection efficiency, but the large sensitive area devices needed have somewhat limited time resolution for single photons. We have observed an additional degradation of the timing at very low light intensities due to delayed events in distribution of signals resulting from multiple fired micro cells. In this work we present the timing properties of AdvanSiD ASD-NUV3S-P-40 SiPM at single photon level picosecond laser illumination and a simple modification of the time-walk correction algorithm, that resulted in reduced degradation of timing resolution due to the delayed events.

Communicating likelihoods and probabilities in forecasts of volcanic eruptions

NASA Astrophysics Data System (ADS)

Doyle, Emma E. H.; McClure, John; Johnston, David M.; Paton, Douglas

2014-02-01

The issuing of forecasts and warnings of natural hazard events, such as volcanic eruptions, earthquake aftershock sequences and extreme weather often involves the use of probabilistic terms, particularly when communicated by scientific advisory groups to key decision-makers, who can differ greatly in relative expertise and function in the decision making process. Recipients may also differ in their perception of relative importance of political and economic influences on interpretation. Consequently, the interpretation of these probabilistic terms can vary greatly due to the framing of the statements, and whether verbal or numerical terms are used. We present a review from the psychology literature on how the framing of information influences communication of these probability terms. It is also unclear as to how people rate their perception of an event's likelihood throughout a time frame when a forecast time window is stated. Previous research has identified that, when presented with a 10-year time window forecast, participants viewed the likelihood of an event occurring ‘today’ as being of less than that in year 10. Here we show that this skew in perception also occurs for short-term time windows (under one week) that are of most relevance for emergency warnings. In addition, unlike the long-time window statements, the use of the phrasing “within the next…” instead of “in the next…” does not mitigate this skew, nor do we observe significant differences between the perceived likelihoods of scientists and non-scientists. This finding suggests that effects occurring due to the shorter time window may be ‘masking’ any differences in perception due to wording or career background observed for long-time window forecasts. These results have implications for scientific advice, warning forecasts, emergency management decision-making, and public information as any skew in perceived event likelihood towards the end of a forecast time window may result in an underestimate of the likelihood of an event occurring ‘today’ leading to potentially inappropriate action choices. We thus present some initial guidelines for communicating such eruption forecasts.

Dual-plane ultrasound flow measurements in liquid metals

NASA Astrophysics Data System (ADS)

Büttner, Lars; Nauber, Richard; Burger, Markus; Räbiger, Dirk; Franke, Sven; Eckert, Sven; Czarske, Jürgen

2013-05-01

An ultrasound measurement system for dual-plane, two-component flow velocity measurements especially in opaque liquids is presented. Present-day techniques for measuring local flow structures in opaque liquids disclose considerable drawbacks concerning line-wise measurement of single ultrasound probes. For studying time-varying flow patterns, conventional ultrasound techniques are either limited by time-consuming mechanical traversing or by the sequential operation of single probes. The measurement system presented within this paper employs four transducer arrays with a total of 100 single elements which allows for flow mapping without mechanical traversing. A high frame rate of several 10 Hz has been achieved due to an efficient parallelization scheme using time-division multiplexing realized by a microcontroller-based electronic switching matrix. The functionality and capability of the measurement system are demonstrated on a liquid metal flow at room temperature inside a cube driven by a rotating magnetic field (RMF). For the first time, the primary and the secondary flow have been studied in detail and simultaneously using a configuration with two crossed measurement planes. The experimental data confirm predictions made by numeric simulation. After a sudden switching on of the RMF, inertial oscillations of the secondary flow were observed by means of a time-resolved measurement with a frame rate of 3.4 Hz. The experiments demonstrate that the presented measurement system is able to investigate complex and transient flow structures in opaque liquids. Due to its ability to study the temporal evolution of local flow structures, the measurement system could provide considerable progress for fluid dynamics research, in particular for applications in the food industry or liquid metal technologies.

39 CFR 3001.38 - Omission of intermediate decisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... intermediate decision upon a finding on the record that due and timely execution of its functions imperatively... opportunity for filing briefs or presenting oral argument to the Commission is desired or waived. Failure of...

Route Planning Software for Lunar Polar Missions

NASA Astrophysics Data System (ADS)

Cunningham, C.; Jones, H.; Amato, J.; Holst, I.; Otten, N.; Kitchell, F.; Whittaker, W.; Horchler, A.

2016-11-01

Rover mission planning on the lunar poles is challenging due to the long, time-varying shadows. This abstract presents software for efficiently planning traverses while balancing competing demands of science goals, rover energy constraints, and risk.

Local oscillator induced degradation of medium-term stability in passive atomic frequency standards

NASA Technical Reports Server (NTRS)

Dick, G. John; Prestage, John D.; Greenhall, Charles A.; Maleki, Lute

1990-01-01

As the performance of passive atomic frequency standards improves, a new limitation is encountered due to frequency fluctuations in an ancillary local oscillator (L.O.). The effect is due to time variation in the gain of the feedback which compensates L.O. frequency fluctuations. The high performance promised by new microwave and optical trapped ion standards may be severely compromised by this effect. Researchers present an analysis of this performance limitation for the case of sequentially interrogated standards. The time dependence of the sensitivity of the interrogation process to L.O. frequency fluctuations is evaluated for single-pulse and double-pulse Ramsey RF interrogation and for amplitude modulated pulses. The effect of these various time dependencies on performance of the standard is calculated for an L.O. with frequency fluctuations showing a typical 1/f spectral density. A limiting 1/sq. root gamma dependent deviation of frequency fluctuations is calculated as a function of pulse lengths, dead time, and pulse overlap. Researchers also present conceptual and hardware-oriented solutions to this problem which achieve a much more nearly constant sensitivity to L.O. fluctuations. Solutions involve use of double-pulse interrogation; alternate interrogation of multiple traps so that the dead time of one trap can be covered by operation of the other; and the use of double-pulse interrogation for two traps, so that during the time of the RF pulses, the increasing sensitivity of one trap tends to compensate for the decreasing sensitivity of the other. A solution making use of amplified-modulated pulses is also presented which shows nominally zero time variation.

Real Time Quality Control Methods for Cued EMI Data Collection

DTIC Science & Technology

2016-01-12

of magnetic geology creating false source locations;  out of the remaining 78 recollects that were due to legitimate sources (i.e., a metal...White River Technologies January 2016 The magnetic geology at the site presented the most significant challenge to the technology and...object, magnetic geology , etc.); however, many of the reacquires due to common errors such as inaccurate target picking could be replaced by in-field

Propagation of stage measurement uncertainties to streamflow time series

NASA Astrophysics Data System (ADS)

Horner, Ivan; Le Coz, Jérôme; Renard, Benjamin; Branger, Flora; McMillan, Hilary

2016-04-01

Streamflow uncertainties due to stage measurements errors are generally overlooked in the promising probabilistic approaches that have emerged in the last decade. We introduce an original error model for propagating stage uncertainties through a stage-discharge rating curve within a Bayesian probabilistic framework. The method takes into account both rating curve (parametric errors and structural errors) and stage uncertainty (systematic and non-systematic errors). Practical ways to estimate the different types of stage errors are also presented: (1) non-systematic errors due to instrument resolution and precision and non-stationary waves and (2) systematic errors due to gauge calibration against the staff gauge. The method is illustrated at a site where the rating-curve-derived streamflow can be compared with an accurate streamflow reference. The agreement between the two time series is overall satisfying. Moreover, the quantification of uncertainty is also satisfying since the streamflow reference is compatible with the streamflow uncertainty intervals derived from the rating curve and the stage uncertainties. Illustrations from other sites are also presented. Results are much contrasted depending on the site features. In some cases, streamflow uncertainty is mainly due to stage measurement errors. The results also show the importance of discriminating systematic and non-systematic stage errors, especially for long term flow averages. Perspectives for improving and validating the streamflow uncertainty estimates are eventually discussed.

On the Evolution of the Late-time Hubble Space Telescope Imaging of the Outburst of the Recurrent Nova RS Ophiuchi (2006)

NASA Astrophysics Data System (ADS)

Ribeiro, V. A. R. M.; Bode, M. F.; Williams, R. E.

2014-12-01

We modelled the late-time Hubble Space Telescope imaging of RS Ophiuchi with models from Ribeiro et al. (2009), which at the time due to the unknown availability of simultaneous ground-based spectroscopy left some open questions as to the evolution of the expanding nebular from the early to the late time observations. Initial emission line identifications suggest that no forbidden lines are present in the spectra and that the emission lines arising in the region of the WFPC2 F502N images are due to N II and He I + Fe II. The best model fit to the spectrum is one where the outer faster moving material expands linearly with time while the inner over-density material either suffered some deceleration or did not change in physical size. The origin of this inner over-density requires further exploration.

Working hours as a risk factor in the development of musculoskeletal complaints.

PubMed

Waersted, M; Westgaard, R H

1991-03-01

The length of daily working hours as a risk factor for the development of musculoskeletal complaints was studied by comparing the sick leave statistics of 408 sewing machine operators on full-time schedules (8 h working day) with 210 operators on part-time schedules (5 h working day). Working part-time was shown to postpone the occurrence of sick leave due to musculoskeletal disorders by approximately half a year. There was no lasting effect on the reduction in working hours on sick leave due to shoulder-neck complaints, but a reduction in low back complaints was indicated. It is suggested that any reorganization of work activities to counteract musculoskeletal injuries from repetitive work should aim to break up the muscular activity patterns over time periods considerably shorter than the 5 h working day of the part-time workers in the present study.

Growth and decline of shoreline industry in Sydney estuary (Australia) and influence on adjacent estuarine sediments.

PubMed

Birch, G F; Lean, J; Gunns, T

2015-06-01

Sydney estuary (Australia), like many urbanised waterways, is degraded due to an extended history of anthropogenic activity. Two major sources of contamination to this estuary are discharge by former shoreline industries and historic and contemporary catchment stormwater. The objectives of the present study were to document changes in shoreline land use from European settlement to the present day and determine the influence of this trend on the metal content of adjacent estuarine sediments. Temporal analysis of land use for seven time horizons between 1788 and 2010 showed rapid expansion of industry along much of the Sydney estuary foreshore soon after European settlement due to the benefits of easy and inexpensive access and readily available water for cooling and power. Shoreline industry attained maximum development in 1978 (32-km length) and declined rapidly to the present-day (9-km length) through redevelopment of industrial sites into medium- to high-density, high-value residential housing. Cores taken adjacent to 11 long-term industrial sites showed that past industrial practices contributed significantly to contamination of estuarine sediment. Subsurface metal concentrations were up to 35 times that of present-day surface sediment and over 100 times greater than natural background concentrations. Sedimentation rates for areas adjacent to shoreline industry were between 0.6 and 2.5 cm/year, and relaxation times were estimated at 50 to 100 years. Natural relaxation and non-disturbance of sediments may be the best management practice in most locations.

Stability Metrics for Simulation and Flight-Software Assessment and Monitoring of Adaptive Control Assist Compensators

NASA Technical Reports Server (NTRS)

Hodel, A. S.; Whorton, Mark; Zhu, J. Jim

2008-01-01

Due to a need for improved reliability and performance in aerospace systems, there is increased interest in the use of adaptive control or other nonlinear, time-varying control designs in aerospace vehicles. While such techniques are built on Lyapunov stability theory, they lack an accompanying set of metrics for the assessment of stability margins such as the classical gain and phase margins used in linear time-invariant systems. Such metrics must both be physically meaningful and permit the user to draw conclusions in a straightforward fashion. We present in this paper a roadmap to the development of metrics appropriate to nonlinear, time-varying systems. We also present two case studies in which frozen-time gain and phase margins incorrectly predict stability or instability. We then present a multi-resolution analysis approach that permits on-line real-time stability assessment of nonlinear systems.

Parareal algorithms with local time-integrators for time fractional differential equations

NASA Astrophysics Data System (ADS)

Wu, Shu-Lin; Zhou, Tao

2018-04-01

It is challenge work to design parareal algorithms for time-fractional differential equations due to the historical effect of the fractional operator. A direct extension of the classical parareal method to such equations will lead to unbalance computational time in each process. In this work, we present an efficient parareal iteration scheme to overcome this issue, by adopting two recently developed local time-integrators for time fractional operators. In both approaches, one introduces auxiliary variables to localized the fractional operator. To this end, we propose a new strategy to perform the coarse grid correction so that the auxiliary variables and the solution variable are corrected separately in a mixed pattern. It is shown that the proposed parareal algorithm admits robust rate of convergence. Numerical examples are presented to support our conclusions.

Investigation of the Regioselectivity of Alkene Hydrations for the Undergraduate Organic Laboratory

ERIC Educational Resources Information Center

Bichler, Katherine A.; Van Ornum, Scott G.; Franz, Margaret C.; Imhoff, Andrea M.

2015-01-01

Due to a lack of time and, thus, an inability to present every possibility in a chemical reaction, organic chemistry professors tend to present each reaction with a single outcome. In practice, this is clearly not the case. A first-semester, three-week laboratory experiment designed for undergraduate organic chemistry students is described in…

A heteroscedastic generalized linear model with a non-normal speed factor for responses and response times.

PubMed

Molenaar, Dylan; Bolsinova, Maria

2017-05-01

In generalized linear modelling of responses and response times, the observed response time variables are commonly transformed to make their distribution approximately normal. A normal distribution for the transformed response times is desirable as it justifies the linearity and homoscedasticity assumptions in the underlying linear model. Past research has, however, shown that the transformed response times are not always normal. Models have been developed to accommodate this violation. In the present study, we propose a modelling approach for responses and response times to test and model non-normality in the transformed response times. Most importantly, we distinguish between non-normality due to heteroscedastic residual variances, and non-normality due to a skewed speed factor. In a simulation study, we establish parameter recovery and the power to separate both effects. In addition, we apply the model to a real data set. © 2017 The Authors. British Journal of Mathematical and Statistical Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

Modeling of electron time variations in the radiation belts

NASA Technical Reports Server (NTRS)

Chan, K. W.; Teague, M. J.; Schofield, N. J.; Vette, J. I.

1979-01-01

A review of the temporal variation in the trapped electron population of the inner and outer radiation zones is presented. Techniques presently used for modeling these zones are discussed and their deficiencies identified. An intermediate region is indicated between the zones in which the present modeling techniques are inadequate due to the magnitude and frequency of magnetic storms. Future trends are examined, and it is suggested that modeling of individual magnetic storms may be required in certain L bands. An analysis of seven magnetic storms is presented, establishing the independence of the depletion time of the storm flux and the storm magnitude. Provisional correlation between the storm magnitude and the Dst index is demonstrated.

UCLA Tokamak Program Close Out Report.

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

Taylor, Robert John

2014-02-04

The results of UCLA experimental fusion program are summarized. Starting with smaller devices like Microtor, Macrotor, CCT and ending the research on the large (5 m) Electric Tokamak. CCT was the most diagnosed device for H-mode like physics and the effects of rotation induced radial fields. ICRF heating was also studied but plasma heating of University Type Tokamaks did not produce useful results due to plasma edge disturbances of the antennae. The Electric Tokamak produced better confinement in the seconds range. However, it presented very good particle confinement due to an "electric particle pinch". This effect prevented us from reachingmore » a quasi steady state. This particle accumulation effect was numerically explained by Shaing's enhanced neoclassical theory. The PI believes that ITER will have a good energy confinement time but deleteriously large particle confinement time and it will disrupt on particle pinching at nominal average densities. The US fusion research program did not study particle transport effects due to its undue focus on the physics of energy confinement time. Energy confinement time is not an issue for energy producing tokamaks. Controlling the ash flow will be very expensive.« less

Management of a patient with autism following ingestion of a foreign body.

PubMed

McCain, Stephen; Tan, Samantha; Mark, David

2014-06-25

Patients with autism often find admission to hospital an anxious time. Awareness of the condition, a speedy diagnosis and flexibility in adapting treatment plans will facilitate early discharge and return to their familiar environment. We describe a patient with severe autism who presented with an acute abdomen secondary to ingestion of a foreign body which required laparotomy. Communication directly to medical staff was greatly limited due to severe autism and close liaison with family members was essential in interpreting scant clinical signs. At the time of surgery a rubber bottle teat was found causing transection of small bowel due to erosion of the foreign body. The postoperative course was fraught with challenges and ensuring side room nursing care with family members present throughout his admission minimised postoperative stress and confusion. We recommend awareness of management strategies for patients with autism to ensure rapid recovery and early discharge home. 2014 BMJ Publishing Group Ltd.

Auxiliary quasi-resonant dc tank electrical power converter

DOEpatents

Peng, Fang Z.

2006-10-24

An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.

Temporal Information Partitioning Networks (TIPNets): A process network approach to infer ecohydrologic shifts

NASA Astrophysics Data System (ADS)

Goodwell, Allison E.; Kumar, Praveen

2017-07-01

In an ecohydrologic system, components of atmospheric, vegetation, and root-soil subsystems participate in forcing and feedback interactions at varying time scales and intensities. The structure of this network of complex interactions varies in terms of connectivity, strength, and time scale due to perturbations or changing conditions such as rainfall, drought, or land use. However, characterization of these interactions is difficult due to multivariate and weak dependencies in the presence of noise, nonlinearities, and limited data. We introduce a framework for Temporal Information Partitioning Networks (TIPNets), in which time-series variables are viewed as nodes, and lagged multivariate mutual information measures are links. These links are partitioned into synergistic, unique, and redundant information components, where synergy is information provided only jointly, unique information is only provided by a single source, and redundancy is overlapping information. We construct TIPNets from 1 min weather station data over several hour time windows. From a comparison of dry, wet, and rainy conditions, we find that information strengths increase when solar radiation and surface moisture are present, and surface moisture and wind variability are redundant and synergistic influences, respectively. Over a growing season, network trends reveal patterns that vary with vegetation and rainfall patterns. The framework presented here enables us to interpret process connectivity in a multivariate context, which can lead to better inference of behavioral shifts due to perturbations in ecohydrologic systems. This work contributes to more holistic characterizations of system behavior, and can benefit a wide variety of studies of complex systems.

Time variations in the Earth's gravity field

NASA Astrophysics Data System (ADS)

Shum, C. K.; Eanes, R. J.

1992-01-01

At the present time, the causes and consequences of changes in the Earth's gravity field due to geophysical and meteorological phenomena are not well understood. The Earth's gravity field represents the complicated distribution of all of the matter that makes up our planet. Its variations are caused by the motions of the solid Earth interacting with the gravitational attraction of the Sun and the Moon (tides) and with the Earth's atmosphere, oceans, polar ice caps and groundwater due to changing weather patterns. These variations influence the rotation of the Earth, alter the orbits of Earth satellites, cause sea level fluctuations, and indirectly affect the global climate pattern.

Thermosolutal Marangoni convection short-time regimes - Proposals for drop tower experiments and real time computer simulation

NASA Astrophysics Data System (ADS)

Polezhaev, V. I.; Ermakov, M. K.

1992-12-01

Results are presented of a parametrical study of flow patterns, heat transfer, and time scales of thermosolutal Marangoni convection in a cavity with temperature and solutal gradients along the free surface and adiabatic bottom for the case of zero gravity. Nusselt number, concentration difference across the cavity, and flow/temperature fields for the different regimes are presented; they show the possibility to use Drop Tower 'Bremen' for measuring the developed secondary flow and heat/mass transfer due to thermosolutal Marangoni convection as well as the possibility to analyze and plan the drop tower for such experiments using the COMGA PC-based system.

An explanation for the anomalous wave profiles obtained in composition B-3 impacted by flat nosed steel rods

NASA Astrophysics Data System (ADS)

James, H. R.; Gustavsen, R. L.; Dattelbaum, D. M.

2017-01-01

In previous work involving firing flat nosed steel rods into the 60/40 RDX/TNT explosive Composition B-3, we found an apparently anomalous "hump" in particle velocity wave profiles. The "hump" occurred on the center-line established by the rod, and at relatively late times, > 1 µs, after detonation onset. Several explanations, including that of a late time reaction, were postulated. This report will present evidence that the anomalous late time "hump" is due to the arrival of rarefaction waves from the rod's periphery. Simple analytic calculations and reactive-burn hydro-code calculations will be presented supporting this hypothesis.

[A review of progress of real-time tumor tracking radiotherapy technology based on dynamic multi-leaf collimator].

PubMed

Liu, Fubo; Li, Guangjun; Shen, Jiuling; Li, Ligin; Bai, Sen

2017-02-01

While radiation treatment to patients with tumors in thorax and abdomen is being performed, further improvement of radiation accuracy is restricted by the tumor intra-fractional motion due to respiration. Real-time tumor tracking radiation is an optimal solution to tumor intra-fractional motion. A review of the progress of real-time dynamic multi-leaf collimator(DMLC) tracking is provided in the present review, including DMLC tracking method, time lag of DMLC tracking system, and dosimetric verification.

Shape of the terrestrial plasma sheet in the near-Earth magnetospheric tail as imaged by the Interstellar Boundary Explorer

DOE PAGES

Dayeh, M. A.; Fuselier, S. A.; Funsten, H. O.; ...

2015-04-11

We present remote, continuous observations from the Interstellar Boundary Explorer of the terrestrial plasma sheet location back to -16 Earth radii (R E) in the magnetospheric tail using energetic neutral atom emissions. The time period studied includes two orbits near the winter and summer solstices, thus associated with large negative and positive dipole tilt, respectively. Continuous side-view images reveal a complex shape that is dominated mainly by large-scale warping due to the diurnal motion of the dipole axis. Superposed on the global warped geometry are short-time fluctuations in plasma sheet location that appear to be consistent with plasma sheet flappingmore » and possibly twisting due to changes in the interplanetary conditions. We conclude that the plasma sheet warping due to the diurnal motion dominates the average shape of the plasma sheet. Over short times, the position of the plasma sheet can be dominated by twisting and flapping.« less

Time series analysis of Mexico City subsidence constrained by radar interferometry

NASA Astrophysics Data System (ADS)

López-Quiroz, Penélope; Doin, Marie-Pierre; Tupin, Florence; Briole, Pierre; Nicolas, Jean-Marie

2009-09-01

In Mexico City, subsidence rates reach up to 40 cm/yr mainly due to soil compaction led by the over exploitation of the Mexico Basin aquifer. In this paper, we map the spatial and temporal patterns of the Mexico City subsidence by differential radar interferometry, using 38 ENVISAT images acquired between end of 2002 and beginning of 2007. We present the severe interferogram unwrapping problems partly due to the coherence loss but mostly due to the high fringe rates. These difficulties are overcome by designing a new methodology that helps the unwrapping step. Our approach is based on the fact that the deformation shape is stable for similar time intervals during the studied period. As a result, a stack of the five best interferograms can be used to compute an average deformation rate for a fixed time interval. Before unwrapping, the number of fringes is then decreased in wrapped interferograms using a scaled version of the stack together with the estimation of the atmospheric phase contribution related with the troposphere vertical stratification. The residual phase, containing less fringes, is more easily unwrapped than the original interferogram. The unwrapping procedure is applied in three iterative steps. The 71 small baseline unwrapped interferograms are inverted to obtain increments of radar propagation delays between the 38 acquisition dates. Based on the redundancy of the interferometric data base, we quantify the unwrapping errors and show that they are strongly decreased by iterations in the unwrapping process. A map of the RMS interferometric system misclosure allows to define the unwrapping reliability for each pixel. Finally, we present a new algorithm for time series analysis that differs from classical SVD decomposition and is best suited to the present data base. Accurate deformation time series are then derived over the metropolitan area of the city with a spatial resolution of 30 × 30 m.

Portable data collection terminal in the automated power consumption measurement system

NASA Astrophysics Data System (ADS)

Vologdin, S. V.; Shushkov, I. D.; Bysygin, E. K.

2018-01-01

Aim of efficiency increasing, automation process of electric energy data collection and processing is very important at present time. High cost of classic electric energy billing systems prevent from its mass application. Udmurtenergo Branch of IDGC of Center and Volga Region developed electronic automated system called “Mobile Energy Billing” based on data collection terminals. System joins electronic components based on service-oriented architecture, WCF services. At present time all parts of Udmurtenergo Branch electric network are connected to “Mobile Energy Billing” project. System capabilities are expanded due to flexible architecture.

Measuring Software Timing Errors in the Presentation of Visual Stimuli in Cognitive Neuroscience Experiments

PubMed Central

Garaizar, Pablo; Vadillo, Miguel A.; López-de-Ipiña, Diego; Matute, Helena

2014-01-01

Because of the features provided by an abundance of specialized experimental software packages, personal computers have become prominent and powerful tools in cognitive research. Most of these programs have mechanisms to control the precision and accuracy with which visual stimuli are presented as well as the response times. However, external factors, often related to the technology used to display the visual information, can have a noticeable impact on the actual performance and may be easily overlooked by researchers. The aim of this study is to measure the precision and accuracy of the timing mechanisms of some of the most popular software packages used in a typical laboratory scenario in order to assess whether presentation times configured by researchers do not differ from measured times more than what is expected due to the hardware limitations. Despite the apparent precision and accuracy of the results, important issues related to timing setups in the presentation of visual stimuli were found, and they should be taken into account by researchers in their experiments. PMID:24409318

New methodology for dynamic lot dispatching

NASA Astrophysics Data System (ADS)

Tai, Wei-Herng; Wang, Jiann-Kwang; Lin, Kuo-Cheng; Hsu, Yi-Chin

1994-09-01

This paper presents a new dynamic dispatching rule to improve delivery. The dynamic dispatching rule named `SLACK and OTD (on time delivery)' is developed for focusing on due date and target cycle time under the environment of IC manufacturing. This idea uses traditional SLACK policy to control long term due date and new OTD policy to reflect the short term stage queue time. Through the fuzzy theory, these two policies are combined as the dispatching controller to define the lot priority in the entire production line. Besides, the system would automatically update the lot priority according to the current line situation. Since the wafer dispatching used to be controlled by critical ratio that indicates the low customer satisfaction. And the overall slack time in the front end of the process is greater compared to that in the rear end of the process which reveals that the machines in the rear end are overloaded by rush orders. When SLACK and OTD are used the due date control has been gradually improved. The wafer with either a long stage queue time or urgent due date will be pushed through the overall production line instead of jammed in the front end. A demand pull system is also developed to satisfy not only due date but also the quantity of monthly demand. The SLACK and OTD rule has been implemented in Taiwan Semiconductor Manufacturing Company for eight months with beneficial results. In order to clearly monitor the SLACK and OTD policy, a method called box chart is generated to simulate the entire production system. From the box chart, we can not only monitor the result of decision policy but display the production situation on the density figure. The production cycle time and delivery situation can also be investigated.

Industrial Relations (The National Shipbuilding Research Program)

DTIC Science & Technology

1981-01-01

permit- ting him so to do, he shall notify his supervisor promptly expost facto . 2. In case of non-attendance due to injury or illness, the mployees shall...this study possible. Special appreciation is due the following individuals who provided. their time and information in the conduct of this study . Aioi...The material contained herein was-developed from the study of the Industrial Relations programs and systems presently in-operation in the shipyards of

Ileocecal Obstruction Due to Endometriosis – A Case Report and Literature Review

PubMed Central

BACALBASA, NICOLAE; BALESCU, IRINA; FILIPESCU, ALEXANDRU

2017-01-01

Endometriosis is a common finding in premenopausal women and a significant number of cases presenting digestive tract involvement at the time of diagnosis. However, most of these patients present pelvic nodules involving the rectosigmoidian junction, other digestive tract segments being less commonly affected. We present the case of a 37-year-old nulliparous woman who presented for diffuse abdominal pain and vomiting; she was diagnosed with complete ileocecal obstruction due to an endometriosis nodule in association with bilateral ovarian endometriosis lesions invading the rectosigmodian wall. A right colectomy with ileocolic anastomosis in association with bilateral cystectomy and rectosigmodian resection was successfully performed. The histopathological examination confirmed the endometriosic origin of the nodules invading the rectosigmodian and ileocecal wall, that was similar to the one described at the level of the ovarian cysts. PMID:28882972

Millisecond Pulsar Timing Precision with NICER

NASA Astrophysics Data System (ADS)

Deneva, Julia; Ray, Paul S.; Ransom, Scott; Wood, Kent S.; Kerr, Matthew T.; Lommen, Andrea; Arzoumanian, Zaven; Black, Kevin; Gendreau, Keith C.; Lewandowska, Natalia; Markwardt, Craig B.; Price, Samuel; Winternitz, Luke

2018-01-01

The Neutron Star Interior Composition Explorer (NICER) is an array of 56 X-ray detectors mounted on the outside of the International Space Station. It allows high-precision timing of millisecond pulsars (MSPs) without the pulse broadening effects due to dispersion and scattering by the interstellar medium that plague radio timing. We present initial timing results from four months of NICER data on the MSPs B1937+21, B1821-24, and J0218+4232, and compare them to simulations and theoretical models for X-ray times-of-arrival, and radio observations.

Nanotoxicology: the present and the future

EPA Science Inventory

Engineered nanomaterials, due to their unique properties, can enable novel applications, but at the same time raise concern about potential toxicity. The knowledge of nanotoxicology developed quickly in recent years on not only the biological effects of nanomaterials, but also on...

Method to improve the blade tip-timing accuracy of fiber bundle sensor under varying tip clearance

NASA Astrophysics Data System (ADS)

Duan, Fajie; Zhang, Jilong; Jiang, Jiajia; Guo, Haotian; Ye, Dechao

2016-01-01

Blade vibration measurement based on the blade tip-timing method has become an industry-standard procedure. Fiber bundle sensors are widely used for tip-timing measurement. However, the variation of clearance between the sensor and the blade will bring a tip-timing error to fiber bundle sensors due to the change in signal amplitude. This article presents methods based on software and hardware to reduce the error caused by the tip clearance change. The software method utilizes both the rising and falling edges of the tip-timing signal to determine the blade arrival time, and a calibration process suitable for asymmetric tip-timing signals is presented. The hardware method uses an automatic gain control circuit to stabilize the signal amplitude. Experiments are conducted and the results prove that both methods can effectively reduce the impact of tip clearance variation on the blade tip-timing and improve the accuracy of measurements.

Proceedings of the Naval Training Device Center and Industry Conference (2nd, november 28-30, 1967).

ERIC Educational Resources Information Center

Naval Training Device Center, Orlando, FL.

This report consists of 40 conference papers actually presented, and four others submitted but not presented due to lack of time. It concentrates on the technical problems confronting organizations having a prime interest in simulation for training, and stresses the cooperation of the military educator and the technical community to achieve a…

Advances in shock timing experiments on the National Ignition Facility

NASA Astrophysics Data System (ADS)

Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Hohenberger, M.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.

2016-03-01

Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion (ICF) implosions were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique.

Catching Up on State Transitions in Cygnus X-1

NASA Technical Reports Server (NTRS)

Boeck, Moritz; Hanke, Manfred; Wilms, Joern; Pirner, Stefan; Grinberg, Victoria; Markoff, Sera; Pottschmidt, Katja; Nowak, Michael A.; Pooley, Guy

2008-01-01

In 2005 February we observed Cygnus X-1 over a period of 10 days quasi-continuously with the Rossi X-ray Timing Explorer and the Ryle telescope. We present the results of the spectral and timing analysis on a timescale of 90 min and show that the behavior of Cyg X-1 is similar to that found during our years long monitoring campaign. As a highlight we present evidence for a full transition from the hard to the soft state that happened during less than three hours. The observation provided a more complete picture of a state transition than before, especially concerning the evolution of the time lags, due to unique transition coverage and analysis with high time resolution.

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

DOE PAGES

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

2016-08-02

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

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

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

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

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

Estimating investment worthiness of an ergonomic intervention for preventing low back pain from a firm's perspective.

PubMed

Hughes, Richard E; Nelson, Nancy A

2009-05-01

A mathematical model was developed for estimating the net present value (NPV) of the cash flow resulting from an investment in an intervention to prevent occupational low back pain (LBP). It combines biomechanics, epidemiology, and finance to give an integrated tool for a firm to use to estimate the investment worthiness of an intervention based on a biomechanical analysis of working postures and hand loads. The model can be used by an ergonomist to estimate the investment worthiness of a proposed intervention. The analysis would begin with a biomechanical evaluation of the current job design and post-intervention job. Economic factors such as hourly labor cost, overhead, workers' compensation costs of LBP claims, and discount rate are combined with the biomechanical analysis to estimate the investment worthiness of the proposed intervention. While this model is limited to low back pain, the simulation framework could be applied to other musculoskeletal disorders. The model uses Monte Carlo simulation to compute the statistical distribution of NPV, and it uses a discrete event simulation paradigm based on four states: (1) working and no history of lost time due to LBP, (2) working and history of lost time due to LBP, (3) lost time due to LBP, and (4) leave job. Probabilities of transitions are based on an extensive review of the epidemiologic review of the low back pain literature. An example is presented.

Well-balanced compressible cut-cell simulation of atmospheric flow.

PubMed

Klein, R; Bates, K R; Nikiforakis, N

2009-11-28

Cut-cell meshes present an attractive alternative to terrain-following coordinates for the representation of topography within atmospheric flow simulations, particularly in regions of steep topographic gradients. In this paper, we present an explicit two-dimensional method for the numerical solution on such meshes of atmospheric flow equations including gravitational sources. This method is fully conservative and allows for time steps determined by the regular grid spacing, avoiding potential stability issues due to arbitrarily small boundary cells. We believe that the scheme is unique in that it is developed within a dimensionally split framework, in which each coordinate direction in the flow is solved independently at each time step. Other notable features of the scheme are: (i) its conceptual and practical simplicity, (ii) its flexibility with regard to the one-dimensional flux approximation scheme employed, and (iii) the well-balancing of the gravitational sources allowing for stable simulation of near-hydrostatic flows. The presented method is applied to a selection of test problems including buoyant bubble rise interacting with geometry and lee-wave generation due to topography.

Real time eye tracking using Kalman extended spatio-temporal context learning

NASA Astrophysics Data System (ADS)

Munir, Farzeen; Minhas, Fayyaz ul Amir Asfar; Jalil, Abdul; Jeon, Moongu

2017-06-01

Real time eye tracking has numerous applications in human computer interaction such as a mouse cursor control in a computer system. It is useful for persons with muscular or motion impairments. However, tracking the movement of the eye is complicated by occlusion due to blinking, head movement, screen glare, rapid eye movements, etc. In this work, we present the algorithmic and construction details of a real time eye tracking system. Our proposed system is an extension of Spatio-Temporal context learning through Kalman Filtering. Spatio-Temporal Context Learning offers state of the art accuracy in general object tracking but its performance suffers due to object occlusion. Addition of the Kalman filter allows the proposed method to model the dynamics of the motion of the eye and provide robust eye tracking in cases of occlusion. We demonstrate the effectiveness of this tracking technique by controlling the computer cursor in real time by eye movements.

Triple diagnostics for early detection of ambivalent necrotizing fasciitis.

PubMed

Hietbrink, Falco; Bode, Lonneke G; Riddez, Louis; Leenen, Luke P H; van Dijk, Marijke R

2016-01-01

Necrotizing fasciitis is an uncommon, rapidly progressive and potential lethal condition. Over the last decade time to surgery decreased and outcome improved, most likely due to increased awareness and more timely referral. Early recognition is key to improve mortality and morbidity. However, early referral frequently makes it a challenge to recognize this heterogeneous disease in its initial stages. Signs and symptoms might be misleading or absent, while the most prominent skin marks might be in discrepancy with the position of the fascial necrosis. Gram staining and especially fresh frozen section histology might be a useful adjunct. Retrospective analysis of 3 year period. Non-transferred patients who presented with suspected necrotizing fasciitis are included. ASA classification was determined. Mortality was documented. In total, 21 patients are included. Most patients suffered from severe comorbidities. In 11 patients, diagnoses was confirmed based on intra-operative macroscopic findings. Histology and/or microbiotic findings resulted in 6/10 remaining patients in a change in treatment strategy. In total, 17 patients proved to suffer necrotizing fasciitis. In the cohort series 2 patients died due to necrotizing fasciitis. In the early phases of necrotizing fasciitis, clinical presentation can be ambivalent. In the present cohort, triple diagnostics consisting of an incisional biopsy with macroscopic, histologic and microbiotic findings was helpful in timely identification of necrotizing fasciitis.

Priming the holiday spirit: persistent activation due to extraexperimental experiences.

PubMed

Coane, Jennifer H; Balota, David A

2009-12-01

The concept of activation is a critical component of many models of cognition. A key characteristic of activation is that recent experience with a concept or stimulus increases the accessibility of the corresponding representation. The extent to which increases in accessibility occur as a result of experiences outside of laboratory settings has not been extensively explored. In the present study, we presented lexical stimuli associated with different holidays and festivities over the course of a year in a lexical decision task. When stimulus meaning and time of testing were congruent (e.g., leprechaun in March), response times were faster and accuracy greater than when meaning and time of test were incongruent (e.g., leprechaun in November). Congruency also benefited performance on a surprise free recall task of the items presented earlier in the lexical decision task. The discussion focuses on potential theoretical accounts of this heightened accessibility of time-of-the-year-relevant concepts.

Mars Secular Obliquity Change Due to Water Ice Caps

NASA Technical Reports Server (NTRS)

Rubincam, David P.

1998-01-01

Mars may have substantially changed its average axial tilt over geologic time due to the waxing and waning of water ice caps. Depending upon Mars' climate and internal structure, the average obliquity could have increased or decreased through climate friction by tens of degrees. A decrease could account for the apparent youthfulness of the polar layered terrain. Alternatively, Mars' average obliquity may have changed until it became "stuck" at its present value of 24.4 deg.

Simple Model with Time-Varying Fine-Structure ``Constant''

NASA Astrophysics Data System (ADS)

Berman, M. S.

2009-10-01

Extending the original version written in colaboration with L.A. Trevisan, we study the generalisation of Dirac's LNH, so that time-variation of the fine-structure constant, due to varying electrical and magnetic permittivities is included along with other variations (cosmological and gravitational ``constants''), etc. We consider the present Universe, and also an inflationary scenario. Rotation of the Universe is a given possibility in this model.

Real-time operating system timing jitter and its impact on motor control

NASA Astrophysics Data System (ADS)

Proctor, Frederick M.; Shackleford, William P.

2001-12-01

General-purpose microprocessors are increasingly being used for control applications due to their widespread availability and software support for non-control functions like networking and operator interfaces. Two classes of real-time operating systems (RTOS) exist for these systems. The traditional RTOS serves as the sole operating system, and provides all OS services. Examples include ETS, LynxOS, QNX, Windows CE and VxWorks. RTOS extensions add real-time scheduling capabilities to non-real-time OSes, and provide minimal services needed for the time-critical portions of an application. Examples include RTAI and RTL for Linux, and HyperKernel, OnTime and RTX for Windows NT. Timing jitter is an issue in these systems, due to hardware effects such as bus locking, caches and pipelines, and software effects from mutual exclusion resource locks, non-preemtible critical sections, disabled interrupts, and multiple code paths in the scheduler. Jitter is typically on the order of a microsecond to a few tens of microseconds for hard real-time operating systems, and ranges from milliseconds to seconds in the worst case for soft real-time operating systems. The question of its significance on the performance of a controller arises. Naturally, the smaller the scheduling period required for a control task, the more significant is the impact of timing jitter. Aside from this intuitive relationship is the greater significance of timing on open-loop control, such as for stepper motors, than for closed-loop control, such as for servo motors. Techniques for measuring timing jitter are discussed, and comparisons between various platforms are presented. Techniques to reduce jitter or mitigate its effects are presented. The impact of jitter on stepper motor control is analyzed.

National-Scale Wind Resource Assessment for Power Generation (Presentation)

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

Baring-Gould, E. I.

2013-08-01

This presentation describes the current standards for conducting a national-scale wind resource assessment for power generation, along with the risk/benefit considerations to be considered when beginning a wind resource assessment. The presentation describes changes in turbine technology and viable wind deployment due to more modern turbine technology and taller towers and shows how the Philippines national wind resource assessment evolved over time to reflect changes that arise from updated technologies and taller towers.

Simulation Assisted Risk Assessment Applied to Launch Vehicle Conceptual Design

NASA Technical Reports Server (NTRS)

Mathias, Donovan L.; Go, Susie; Gee, Ken; Lawrence, Scott

2008-01-01

A simulation-based risk assessment approach is presented and is applied to the analysis of abort during the ascent phase of a space exploration mission. The approach utilizes groupings of launch vehicle failures, referred to as failure bins, which are mapped to corresponding failure environments. Physical models are used to characterize the failure environments in terms of the risk due to blast overpressure, resulting debris field, and the thermal radiation due to a fireball. The resulting risk to the crew is dynamically modeled by combining the likelihood of each failure, the severity of the failure environments as a function of initiator and time of the failure, the robustness of the crew module, and the warning time available due to early detection. The approach is shown to support the launch vehicle design process by characterizing the risk drivers and identifying regions where failure detection would significantly reduce the risk to the crew.

Equatorial electrojet responses to intense solar flares under geomagnetic disturbance time electric fields

NASA Astrophysics Data System (ADS)

Abdu, M. A.; Nogueira, P. A. B.; Souza, J. R.; Batista, I. S.; Dutra, S. L. G.; Sobral, J. H. A.

2017-03-01

Large enhancement in the equatorial electrojet (EEJ) current can occur due to sudden increase in the E layer density arising from solar flare associated ionizing radiations, as also from background electric fields modified by magnetospheric disturbances when present before or during a solar flare. We investigate the EEJ responses at widely separated longitudes during two X-class flares that occurred at different activity phases surrounding the magnetic super storm sequences of 28-29 October 2003. During the 28 October flare we observed intense reverse electrojet under strong westward electric field in the sunrise sector over Jicamarca. Sources of westward disturbance electric fields driving large EEJ current are identified for the first time. Model calculations on the E layer density, with and without flare, and comparison of the results between Jicamarca and Sao Luis suggested enhanced westward electric field due to the flare occurring close to sunrise (over Jicamarca). During the flare on 29 October, which occurred during a rapid AE recovery, a strong overshielding electric field of westward polarity over Jicamarca delayed an expected EEJ eastward growth due to flare-induced ionization enhancement in the afternoon. This EEJ response yielded a measure of the overshielding decay time determined by the storm time Region 2 field-aligned current. This paper will present a detailed analysis of the EEJ responses during the two flares, including a quantitative evaluation of the flare-induced electron density enhancements and identification of electric field sources that played dominant roles in the large westward EEJ at the sunrise sector over Jicamarca.

Pyrenochaeta romeroi causing subcutaneous phaeohyphomycotic cyst in a diabetic female.

PubMed

Yadav, Sarita; Agarwal, Ruchi; Singh, Sundeep; Goel, Shikha

2015-06-01

Opportunistic subcutaneous fungal infections are increasing in present times due to increasing incidence of many medical conditions causing immunosupression like diabetes, AIDS, organ transplant recipients and anticancer therapy. Pyrenochaeta romeroi, a fungus from the dematiaceae group, first described by Borelli in 1959, is saprophyte to soil and plants.We present a rare case of subcutaneous phaeohyphomycotic cyst in a diabetic female caused by P. romeroi.

Ileocecal Obstruction Due to Endometriosis - A Case Report and Literature Review.

PubMed

Bacalbasa, Nicolae; Balescu, Irina; Filipescu, Alexandru

2017-01-01

Endometriosis is a common finding in premenopausal women and a significant number of cases presenting digestive tract involvement at the time of diagnosis. However, most of these patients present pelvic nodules involving the rectosigmoidian junction, other digestive tract segments being less commonly affected. We present the case of a 37-year-old nulliparous woman who presented for diffuse abdominal pain and vomiting; she was diagnosed with complete ileocecal obstruction due to an endometriosis nodule in association with bilateral ovarian endometriosis lesions invading the rectosigmodian wall. A right colectomy with ileocolic anastomosis in association with bilateral cystectomy and rectosigmodian resection was successfully performed. The histopathological examination confirmed the endometriosic origin of the nodules invading the rectosigmodian and ileocecal wall, that was similar to the one described at the level of the ovarian cysts. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Nonlinear (time domain) and linearized (time and frequency domain) solutions to the compressible Euler equations in conservation law form

NASA Technical Reports Server (NTRS)

Sreenivas, Kidambi; Whitfield, David L.

1995-01-01

Two linearized solvers (time and frequency domain) based on a high resolution numerical scheme are presented. The basic approach is to linearize the flux vector by expressing it as a sum of a mean and a perturbation. This allows the governing equations to be maintained in conservation law form. A key difference between the time and frequency domain computations is that the frequency domain computations require only one grid block irrespective of the interblade phase angle for which the flow is being computed. As a result of this and due to the fact that the governing equations for this case are steady, frequency domain computations are substantially faster than the corresponding time domain computations. The linearized equations are used to compute flows in turbomachinery blade rows (cascades) arising due to blade vibrations. Numerical solutions are compared to linear theory (where available) and to numerical solutions of the nonlinear Euler equations.

Using GLONASS signal for clock synchronization

NASA Technical Reports Server (NTRS)

Gouzhva, Yuri G.; Gevorkyan, Arvid G.; Bogdanov, Pyotr P.; Ovchinnikov, Vitaly V.

1994-01-01

Although in accuracy parameters GLONASS is correlated with GPS, using GLONASS signals for high-precision clock synchronization was, up to the recent time, of limited utility due to the lack of specialized time receivers. In order to improve this situation, in late 1992 the Russian Institute of Radionavigation and Time (RMT) began to develop a GLONASS time receiver using as a basis the airborne ASN-16 receiver. This paper presents results of estimating user clock synchronization accuracy via GLONASS signals using ASN-16 receiver in the direct synchronization and common-view modes.

Role of Off-Line-of-Sight Propagation in Geomagnetic EMP Formation

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

Kruger, Hans W.

The author’s synchrotron radiation based 3D geomagnetic EMP code MACSYNC has been used to explore the impact on pulse rise time and air conductivity of EMP propagation paths to the observer that are located off the direct line-of-sight (LOS) between gamma source and observer. This geometry is always present because, for an isotropic source, most the gammas are emitted at an angle with respect to the LOS. Computations for a 1 kt near-surface burst observed from space yield two principal findings: 1. The rise time is generated by the combined actions of a) electron spreading along the LOS due tomore » the Compton electron emission angular distribution folded with electron multiple scattering effects, and b) radiation arrival time spreading due to length differences for different off-LOS propagation paths. The pulse rise time does not depend on the rise time of the conductivity. The conductivity rise time determines the pulse amplitude. 2. One-dimensional legacy EMP codes are inherently incapable of producing the correct pulse shape because they cannot treat the dependence of the conductivity on two dimensions, i.e. the radius from the source and the angle of the propagation path with the LOS. This divergence from one-dimensionality begins at a small fraction of a nanosecond for a sea-level burst. This effect will also be present in high-altitude bursts, however, determination of its onset time and magnitude requires high-altitude computations which have not yet been done.« less

Illumina Unamplified Indexed Library Construction: An Automated Approach

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

Hack, Christopher A.; Sczyrba, Alexander; Cheng, Jan-Fang

Manual library construction is a limiting factor in Illumina sequencing. Constructing libraries by hand is costly, time-consuming, low-throughput, and ergonomically hazardous, and constructing multiple libraries introduces risk of library failure due to pipetting errors. The ability to construct multiple libraries simultaneously in automated fashion represents significant cost and time savings. Here we present a strategy to construct up to 96 unamplified indexed libraries using Illumina TruSeq reagents and a Biomek FX robotic platform. We also present data to indicate that this library construction method has little or no risk of cross-contamination between samples.

Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology

NASA Technical Reports Server (NTRS)

Chamitoff, Gregory Errol

1992-01-01

Intelligent optimization methods are applied to the problem of real-time flight control for a class of airbreathing hypersonic vehicles (AHSV). The extreme flight conditions that will be encountered by single-stage-to-orbit vehicles, such as the National Aerospace Plane, present a tremendous challenge to the entire spectrum of aerospace technologies. Flight control for these vehicles is particularly difficult due to the combination of nonlinear dynamics, complex constraints, and parametric uncertainty. An approach that utilizes all available a priori and in-flight information to perform robust, real time, short-term trajectory planning is presented.

Lagrangian and Eulerian statistics obtained from direct numerical simulations of homogeneous turbulence

NASA Technical Reports Server (NTRS)

Squires, Kyle D.; Eaton, John K.

1991-01-01

Direct numerical simulation is used to study dispersion in decaying isotropic turbulence and homogeneous shear flow. Both Lagrangian and Eulerian data are presented allowing direct comparison, but at fairly low Reynolds number. The quantities presented include properties of the dispersion tensor, isoprobability contours of particle displacement, Lagrangian and Eulerian velocity autocorrelations and time scale ratios, and the eddy diffusivity tensor. The Lagrangian time microscale is found to be consistently larger than the Eulerian microscale, presumably due to the advection of the small scales by the large scales in the Eulerian reference frame.

Bounds on Time Reversal Violation From Polarized Neutron Capture With Unpolarized Targets.

PubMed

Davis, E D; Gould, C R; Mitchell, G E; Sharapov, E I

2005-01-01

We have analyzed constraints on parity-odd time-reversal noninvariant interactions derived from measurements of the energy dependence of parity-violating polarized neutron capture on unpolarized targets. As previous authors found, a perturbation in energy dependence due to a parity (P)-odd time (T)-odd interaction is present. However, the perturbation competes with T-even terms which can obscure the T-odd signature. We estimate the magnitudes of these competing terms and suggest strategies for a practicable experiment.

An Empirical Model of Radiation Belt Electron Pitch Angle Distributions Based On Van Allen Probes Measurements

NASA Astrophysics Data System (ADS)

Zhao, H.; Friedel, R. H. W.; Chen, Y.; Reeves, G. D.; Baker, D. N.; Li, X.; Jaynes, A. N.; Kanekal, S. G.; Claudepierre, S. G.; Fennell, J. F.; Blake, J. B.; Spence, H. E.

2018-05-01

Based on over 4 years of Van Allen Probes measurements, an empirical model of radiation belt electron equatorial pitch angle distribution (PAD) is constructed. The model, developed by fitting electron PADs with Legendre polynomials, provides the statistical PADs as a function of L-shell (L = 1-6), magnetic local time, electron energy ( 30 keV to 5.2 MeV), and geomagnetic activity (represented by the Dst index) and is also the first empirical PAD model in the inner belt and slot region. For megaelectron volt electrons, model results show more significant day-night PAD asymmetry of electrons with higher energies and during disturbed times, which is caused by geomagnetic field configuration and flux radial gradient changes. Steeper PADs with higher fluxes around 90° pitch angle and lower fluxes at lower pitch angles for higher-energy electrons and during active times are also present, which could be due to electromagnetic ion cyclotron wave scattering. For hundreds of kiloelectron volt electrons, cap PADs are generally present in the slot region during quiet times and their energy-dependent features are consistent with hiss wave scattering, while during active times, cap PADs are less significant especially at outer part of slot region, which could be due to the complex energizing and transport processes. The 90°-minimum PADs are persistently present in the inner belt and appear in the slot region during active times, and minima at 90° pitch angle are more significant for electrons with higher energies, which could be a critical evidence in identifying the underlying physical processes responsible for the formation of 90°-minimum PADs.

Vertebral osteomyelitis with a rare etiology diagnosed by fine-needle aspiration cytology.

PubMed

B N, Nandeesh; Kini, Usha; Alexander, Betty

2010-05-01

Invasive fungal infections are rare in immunocompromised individuals, but are not uncommon in immunologically compromised patients. Bone involvement by these infections, though exceedingly rare, may occur due to direct extension of the infection from a neighboring organ or due to hematogenous dissemination in critically ill patients. Still rarer is the invasive aspergillosis involving either the vertebral body or the intervertebral disc with extension into the extradural space as an abscess. We report one such case of vertebral osteomyelitis due to Aspergillus diagnosed by FNAC in a well-controlled diabetic patient who presented with nonspecific symptoms and in whom a clinical and radiological diagnosis of Pott's spine was considered. The present case stresses the importance of early cytologic diagnosis of vertebral Aspergillus osteomyelitis, which in conjunction with appropriate timely medical and surgical treatment, offers good recovery without much sequelae or threat to life.

Centuries of thermal sea-level rise due to anthropogenic emissions of short-lived greenhouse gases

PubMed Central

Zickfeld, Kirsten

2017-01-01

Mitigation of anthropogenic greenhouse gases with short lifetimes (order of a year to decades) can contribute to limiting warming, but less attention has been paid to their impacts on longer-term sea-level rise. We show that short-lived greenhouse gases contribute to sea-level rise through thermal expansion (TSLR) over much longer time scales than their atmospheric lifetimes. For example, at least half of the TSLR due to increases in methane is expected to remain present for more than 200 y, even if anthropogenic emissions cease altogether, despite the 10-y atmospheric lifetime of this gas. Chlorofluorocarbons and hydrochlorofluorocarbons have already been phased out under the Montreal Protocol due to concerns about ozone depletion and provide an illustration of how emission reductions avoid multiple centuries of future TSLR. We examine the “world avoided” by the Montreal Protocol by showing that if these gases had instead been eliminated in 2050, additional TSLR of up to about 14 cm would be expected in the 21st century, with continuing contributions lasting more than 500 y. Emissions of the hydrofluorocarbon substitutes in the next half-century would also contribute to centuries of future TSLR. Consideration of the time scales of reversibility of TSLR due to short-lived substances provides insights into physical processes: sea-level rise is often assumed to follow air temperature, but this assumption holds only for TSLR when temperatures are increasing. We present a more complete formulation that is accurate even when atmospheric temperatures are stable or decreasing due to reductions in short-lived gases or net radiative forcing. PMID:28069937

Centuries of thermal sea-level rise due to anthropogenic emissions of short-lived greenhouse gases.

PubMed

Zickfeld, Kirsten; Solomon, Susan; Gilford, Daniel M

2017-01-24

Mitigation of anthropogenic greenhouse gases with short lifetimes (order of a year to decades) can contribute to limiting warming, but less attention has been paid to their impacts on longer-term sea-level rise. We show that short-lived greenhouse gases contribute to sea-level rise through thermal expansion (TSLR) over much longer time scales than their atmospheric lifetimes. For example, at least half of the TSLR due to increases in methane is expected to remain present for more than 200 y, even if anthropogenic emissions cease altogether, despite the 10-y atmospheric lifetime of this gas. Chlorofluorocarbons and hydrochlorofluorocarbons have already been phased out under the Montreal Protocol due to concerns about ozone depletion and provide an illustration of how emission reductions avoid multiple centuries of future TSLR. We examine the "world avoided" by the Montreal Protocol by showing that if these gases had instead been eliminated in 2050, additional TSLR of up to about 14 cm would be expected in the 21st century, with continuing contributions lasting more than 500 y. Emissions of the hydrofluorocarbon substitutes in the next half-century would also contribute to centuries of future TSLR. Consideration of the time scales of reversibility of TSLR due to short-lived substances provides insights into physical processes: sea-level rise is often assumed to follow air temperature, but this assumption holds only for TSLR when temperatures are increasing. We present a more complete formulation that is accurate even when atmospheric temperatures are stable or decreasing due to reductions in short-lived gases or net radiative forcing.

Frequency synchronization of a frequency-hopped MFSK communication system

NASA Technical Reports Server (NTRS)

Huth, G. K.; Polydoros, A.; Simon, M. K.

1981-01-01

This paper presents the performance of fine-frequency synchronization. The performance degradation due to imperfect frequency synchronization is found in terms of the effect on bit error probability as a function of full-band or partial-band noise jamming levels and of the number of frequency hops used in the estimator. The effect of imperfect fine-time synchronization is also included in the calculation of fine-frequency synchronization performance to obtain the overall performance degradation due to synchronization errors.

Generation of optimum vertical profiles for an advanced flight management system

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Waters, M. H.

1981-01-01

Algorithms for generating minimum fuel or minimum cost vertical profiles are derived and examined. The option for fixing the time of flight is included in the concepts developed. These algorithms form the basis for the design of an advanced on-board flight management system. The variations in the optimum vertical profiles (resulting from these concepts) due to variations in wind, takeoff mass, and range-to-destination are presented. Fuel savings due to optimum climb, free cruise altitude, and absorbing delays enroute are examined.

Estimation of Time-Varying Pilot Model Parameters

NASA Technical Reports Server (NTRS)

Zaal, Peter M. T.; Sweet, Barbara T.

2011-01-01

Human control behavior is rarely completely stationary over time due to fatigue or loss of attention. In addition, there are many control tasks for which human operators need to adapt their control strategy to vehicle dynamics that vary in time. In previous studies on the identification of time-varying pilot control behavior wavelets were used to estimate the time-varying frequency response functions. However, the estimation of time-varying pilot model parameters was not considered. Estimating these parameters can be a valuable tool for the quantification of different aspects of human time-varying manual control. This paper presents two methods for the estimation of time-varying pilot model parameters, a two-step method using wavelets and a windowed maximum likelihood estimation method. The methods are evaluated using simulations of a closed-loop control task with time-varying pilot equalization and vehicle dynamics. Simulations are performed with and without remnant. Both methods give accurate results when no pilot remnant is present. The wavelet transform is very sensitive to measurement noise, resulting in inaccurate parameter estimates when considerable pilot remnant is present. Maximum likelihood estimation is less sensitive to pilot remnant, but cannot detect fast changes in pilot control behavior.

Robotic reactions: delay-induced patterns in autonomous vehicle systems.

PubMed

Orosz, Gábor; Moehlis, Jeff; Bullo, Francesco

2010-02-01

Fundamental design principles are presented for vehicle systems governed by autonomous cruise control devices. By analyzing the corresponding delay differential equations, it is shown that for any car-following model short-wavelength oscillations can appear due to robotic reaction times, and that there are tradeoffs between the time delay and the control gains. The analytical findings are demonstrated on an optimal velocity model using numerical continuation and numerical simulation.

Robotic reactions: Delay-induced patterns in autonomous vehicle systems

NASA Astrophysics Data System (ADS)

Orosz, Gábor; Moehlis, Jeff; Bullo, Francesco

2010-02-01

Fundamental design principles are presented for vehicle systems governed by autonomous cruise control devices. By analyzing the corresponding delay differential equations, it is shown that for any car-following model short-wavelength oscillations can appear due to robotic reaction times, and that there are tradeoffs between the time delay and the control gains. The analytical findings are demonstrated on an optimal velocity model using numerical continuation and numerical simulation.

Elastic and viscoelastic calculations of stresses in sedimentary basins

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

Warpinski, N.R.

This study presents a method for estimating the stress state within reservoirs at depth using a time-history approach for both elastic and viscoelastic rock behavior. Two features of this model are particularly significant for stress calculations. The first is the time-history approach, where we assume that the present in situ stress is a result of the entire history of the rock mass, rather than due only to the present conditions. The model can incorporate: (1) changes in pore pressure due to gas generation; (2) temperature gradients and local thermal episodes; (3) consolidation and diagenesis through time-varying material properties; and (4)more » varying tectonic episodes. The second feature is the use of a new viscoelastic model. Rather than assume a form of the relaxation function, a complete viscoelastic solution is obtained from the elastic solution through the viscoelastic correspondence principal. Simple rate models are then applied to obtain the final rock behavior. Example calculations for some simple cases are presented that show the contribution of individual stress or strain components. Finally, a complete example of the stress history of rocks in the Piceance basin is attempted. This calculation compares favorably with present-day stress data in this location. This model serves as a predictor for natural fracture genesis and expected rock fracturing from the model is compared with actual fractures observed in this region. These results show that most current estimates of in situ stress at depth do not incorporate all of the important mechanisms and a more complete formulation, such as this study, is required for acceptable stress calculations. The method presented here is general and is applicable to any basin having a relatively simple geologic history. 25 refs., 18 figs.« less

Discrete-Time Mapping for an Impulsive Goodwin Oscillator with Three Delays

NASA Astrophysics Data System (ADS)

Churilov, Alexander N.; Medvedev, Alexander; Zhusubaliyev, Zhanybai T.

A popular biomathematics model of the Goodwin oscillator has been previously generalized to a more biologically plausible construct by introducing three time delays to portray the transport phenomena arising due to the spatial distribution of the model states. The present paper addresses a similar conversion of an impulsive version of the Goodwin oscillator that has found application in mathematical modeling, e.g. in endocrine systems with pulsatile hormone secretion. While the cascade structure of the linear continuous part pertinent to the Goodwin oscillator is preserved in the impulsive Goodwin oscillator, the static nonlinear feedback of the former is substituted with a pulse modulation mechanism thus resulting in hybrid dynamics of the closed-loop system. To facilitate the analysis of the mathematical model under investigation, a discrete mapping propagating the continuous state variables through the firing times of the impulsive feedback is derived. Due to the presence of multiple time delays in the considered model, previously developed mapping derivation approaches are not applicable here and a novel technique is proposed and applied. The mapping captures the dynamics of the original hybrid system and is instrumental in studying complex nonlinear phenomena arising in the impulsive Goodwin oscillator. A simulation example is presented to demonstrate the utility of the proposed approach in bifurcation analysis.

The Effects of Race Conditions When Implementing Single-Source Redundant Clock Trees in Triple Modular Redundant Synchronous Architectures

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; Kim, Hak S.; Phan, Anthony M.; Seidleck, Christina M.; Label, Kenneth A.; Pellish, Jonathan A.; Campola, Michael J.

2016-01-01

We present the challenges that arise when using redundant clock domains due to their time-skew. Radiation data show that a singular clock domain provides an improved triple modular redundant (TMR) scheme over redundant clocks.

Effects of a static inhomogeneous magnetic field acting on a laser-produced carbon plasma plume

NASA Astrophysics Data System (ADS)

Favre, M.; Ruiz, H. M.; Bendixsen, L. S. Caballero; Reyes, S.; Veloso, F.; Wyndham, E.; Bhuyan, H.

2017-08-01

We present time- and space-resolved observations of the dynamics of a laser-produced carbon plasma, propagating in a sub-Tesla inhomogeneous magnetic field, with both, axial and radial field gradients. An Nd:YAG laser pulse, 340 mJ, 3.5 ns, at 1.06 μ m, with a fluence of 7 J/cm2, is used to generate the plasma from a solid graphite target, in vacuum. The magnetic field is produced using two coaxial sets of two NeFeB ring magnets, parallel to the laser target surface. The diagnostics include plasma imaging with 50 ns time resolution, spatially resolved optical emission spectroscopy and Faraday cup. Based on our observations, evidence of radial and axial plasma confinement due to magnetic field gradients is presented. Formation of C2 molecules, previously observed in the presence of a low pressure neutral gas background, and enhanced on-axis ion flux, are ascribed to finite Larmor radius effects and reduced radial transport due to the presence of the magnetic field.

Elastic Model Transitions Using Quadratic Inequality Constrained Least Squares

NASA Technical Reports Server (NTRS)

Orr, Jeb S.

2012-01-01

A technique is presented for initializing multiple discrete finite element model (FEM) mode sets for certain types of flight dynamics formulations that rely on superposition of orthogonal modes for modeling the elastic response. Such approaches are commonly used for modeling launch vehicle dynamics, and challenges arise due to the rapidly time-varying nature of the rigid-body and elastic characteristics. By way of an energy argument, a quadratic inequality constrained least squares (LSQI) algorithm is employed to e ect a smooth transition from one set of FEM eigenvectors to another with no requirement that the models be of similar dimension or that the eigenvectors be correlated in any particular way. The physically unrealistic and controversial method of eigenvector interpolation is completely avoided, and the discrete solution approximates that of the continuously varying system. The real-time computational burden is shown to be negligible due to convenient features of the solution method. Simulation results are presented, and applications to staging and other discontinuous mass changes are discussed

Thermal history of Bakken shale in Williston basin

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

Gosnold, W.D. Jr.; Lefever, R.D.; Crashell, J.J.

1989-12-01

Stratigraphic and thermal conductivity data were combined to analyze the thermostratigraphy of the Williston basin. The present thermostratigraphy is characterized by geothermal gradients of the order of 60 mK/m in the Cenozoic and Mesozoic units, and 30 mK/m in the Paleozoic units. The differences in geothermal gradients are due to differences in thermal conductivities between the shale-dominated Mesozoic and Cenozoic units and the carbonate-dominated Paleozoic units. Subsidence and compaction rates were calculated for the basin and were used to determine models for time vs. depth and time vs. thermal conductivity relationships for the basin. The time/depth and time/conductivity relationships includemore » factors accounting for thermal conductivity changes due to compaction, cementation, and temperature. The thermal history of the Bakken shale, a primary oil source rock in the Williston basin, was determined using four different models, and values for Lopatin's time-temperature index (TTI) were calculated for each model. The first model uses a geothermal gradient calculated from bottom-hole temperature data, the second uses present-day thermostratigraphy, the third uses the thermostratigraphic relationship determined in this analysis, and the fourth modifies the third by including assumed variations in continental heat flow. The thermal histories and the calculated TTI values differ markedly among the models with TTI values differing by a factor of about two between some models.« less

Sandia National Laboratories Small-Scale Sensitivity Testing (SSST) Report: Calcium Nitrate Mixtures with Various Fuels.

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

Phillips, Jason Joe

Based upon the presented sensitivity data for the examined calcium nitrate mixtures using sugar and sawdust, contact handling/mixing of these materials does not present hazards greater than those occurring during handling of dry PETN powder. The aluminized calcium nitrate mixtures present a known ESD fire hazard due to the fine aluminum powder fuel. These mixtures may yet present an ESD explosion hazard, though this has not been investigated at this time. The detonability of these mixtures will be investigated during Phase III testing.

Photographic Identification of Humpback and Blue Whales off the US West Coast: Results and Updated Abundance Estimates from 2008 Field Season

DTIC Science & Technology

2009-12-01

1990s and only being present part of the time off the US West Coast lowering the average density present (but not reflecting an actual population ...the average density present (but not reflecting an actual population decline). 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...due to our sample representing a decreasing proportion of this growing population leading to greater variation and possibly greater susceptibility to

Multi-assortment rhythmic production planning and control

NASA Astrophysics Data System (ADS)

Skolud, B.; Krenczyk, D.; Zemczak, M.

2015-11-01

A method for production planning in a repetitive manufacturing system which allows for estimating the possibility of processing work orders in due time is presented. The difference between two approaches are presented; the first one one-piece flow elaborated in Toyota and the second one elaborated by authors that consists in defining sufficient conditions to filter all solutions and providing a set of admissible solutions for both the client and the producer. In the paper attention is focused on the buffer allocation. Illustrative examples are presented.

Time synchronization of a frequency-hopped MFSK communication system

NASA Technical Reports Server (NTRS)

Simon, M. K.; Polydoros, A.; Huth, G. K.

1981-01-01

In a frequency-hopped (FH) multiple-frequency-shift-keyed (MFSK) communication system, frequency hopping causes the necessary frequency transitions for time synchronization estimation rather than the data sequence as in the conventional (nonfrequency-hopped) system. Making use of this observation, this paper presents a fine synchronization (i.e., time errors of less than a hop duration) technique for estimation of FH timing. The performance degradation due to imperfect FH time synchronization is found in terms of the effect on bit error probability as a function of full-band or partial-band noise jamming levels and of the number of hops used in the FH timing estimate.

Optimal reentry prediction of space objects from LEO using RSM and GA

NASA Astrophysics Data System (ADS)

Mutyalarao, M.; Raj, M. Xavier James

2012-07-01

The accurate estimation of the orbital life time (OLT) of decaying near-Earth objects is of considerable importance for the prediction of risk object re-entry time and hazard assessment as well as for mitigation strategies. Recently, due to the reentries of large number of risk objects, which poses threat to the human life and property, a great concern is developed in the space scientific community all over the World. The evolution of objects in Low Earth Orbit (LEO) is determined by a complex interplay of the perturbing forces, mainly due to atmospheric drag and Earth gravity. These orbits are mostly in low eccentric (eccentricity < 0.2) and have variations in perigee and apogee altitudes due to perturbations during a revolution. The changes in the perigee and apogee altitudes of these orbits are mainly due to the gravitational perturbations of the Earth and the atmospheric density. It has become necessary to use extremely complex force models to match with the present operational requirements and observational techniques. Further the re-entry time of the objects in such orbits is sensitive to the initial conditions. In this paper the problem of predicting re-entry time is attempted as an optimal estimation problem. It is known that the errors are more in eccentricity for the observations based on two line elements (TLEs). Thus two parameters, initial eccentricity and ballistic coefficient, are chosen for optimal estimation. These two parameters are computed with response surface method (RSM) using a genetic algorithm (GA) for the selected time zones, based on rough linear variation of response parameter, the mean semi-major axis during orbit evolution. Error minimization between the observed and predicted mean Semi-major axis is achieved by the application of an optimization algorithm such as Genetic Algorithm (GA). The basic feature of the present approach is that the model and measurement errors are accountable in terms of adjusting the ballistic coefficient and eccentricity. The methodology is tested with the recently reentered objects ROSAT and PHOBOS GRUNT satellites. The study reveals a good agreement with the actual reentry time of these objects. It is also observed that the absolute percentage error in re-entry prediction time for all the two objects is found to be very less. Keywords: low eccentric, Response surface method, Genetic algorithm, apogee altitude, Ballistic coefficient

The Time-Varying Relationship between Mortality and Business Cycles in the USA.

PubMed

Lam, Jean-Paul; Piérard, Emmanuelle

2017-02-01

We examine the relationship between total mortality, deaths due to motor vehicle accidents, cardiovascular disease and measures of business cycles for the USA, using a time-varying parameter model for the periods 1961-2010. We first present a theoretical model to outline the transmission mechanism from business cycles to health status, to motivate our empirical framework and to explain why the relationship between mortality and the economy may have changed over time. We find overwhelming evidence of structural breaks in the relationship between mortality and business cycles over the sample period. Overall, the relationship between total mortality, cardiovascular mortality and the economy has become less procyclical over time and even countercyclical in recent times for certain age groups. Deaths due to motor vehicle accidents have remained strongly procyclical. Using drugs and medical patent data and data on hours worked, we argue that important advances in medical technology and changes in the effects that working hours have on health are important reasons for this time-varying relationship. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Distance Measurement Error in Time-of-Flight Sensors Due to Shot Noise

PubMed Central

Illade-Quinteiro, Julio; Brea, Víctor M.; López, Paula; Cabello, Diego; Doménech-Asensi, Gines

2015-01-01

Unlike other noise sources, which can be reduced or eliminated by different signal processing techniques, shot noise is an ever-present noise component in any imaging system. In this paper, we present an in-depth study of the impact of shot noise on time-of-flight sensors in terms of the error introduced in the distance estimation. The paper addresses the effect of parameters, such as the size of the photosensor, the background and signal power or the integration time, and the resulting design trade-offs. The study is demonstrated with different numerical examples, which show that, in general, the phase shift determination technique with two background measurements approach is the most suitable for pixel arrays of large resolution. PMID:25723141

A comprehensive review on droplet-based bioprinting: Past, present and future.

PubMed

Gudapati, Hemanth; Dey, Madhuri; Ozbolat, Ibrahim

2016-09-01

Droplet-based bioprinting (DBB) offers greater advantages due to its simplicity and agility with precise control on deposition of biologics including cells, growth factors, genes, drugs and biomaterials, and has been a prominent technology in the bioprinting community. Due to its immense versatility, DBB technology has been adopted by various application areas, including but not limited to, tissue engineering and regenerative medicine, transplantation and clinics, pharmaceutics and high-throughput screening, and cancer research. Despite the great benefits, the technology currently faces several challenges such as a narrow range of available bioink materials, bioprinting-induced cell damage at substantial levels, limited mechanical and structural integrity of bioprinted constructs, and restrictions on the size of constructs due to lack of vascularization and porosity. This paper presents a first-time review of DBB and comprehensively covers the existing DBB modalities including inkjet, electrohydrodynamic, acoustic, and micro-valve bioprinting. The recent notable studies are highlighted, the relevant bioink biomaterials and bioprinters are expounded, the application areas are presented, and the future prospects are provided to the reader. Copyright © 2016 Elsevier Ltd. All rights reserved.

Examples of Sentinel-2A Mission Exploitation Results

NASA Astrophysics Data System (ADS)

Koetz, Benjamin; Hoersch, Bianca; Gascon, Ferran; Desnos, Yves-Louis; Seifert, Frank Martin; Paganini, Marc; Ramoino, Fabrizio; Arino, Olivier

2017-04-01

The Sentinel-2 Copernicus mission will bring significant breakthrough in the exploitation of space borne optical data. Sentinel-2 time series will transform land cover, agriculture, forestry, in-land water and costal EO applications from mapping to monitoring, from snapshot to time series data analysis, from image-based to pixel-based processing. The 5-days temporal revisiting of the Sentinel-2 satellites, when both units will be operated together, will usher us in a new era for time series analysis at high spatial resolutions (HR) of 10-20 meters. The monitoring of seasonal variations and processes in phenology and hydrology are examples of the many R&D areas to be studied. The mission's large swath and systematic acquisitions will further support unprecedented coverage at the national scale addressing information requirements of national to regional policies. Within ESA programs, such as the Data User Element (DUE), Scientific Exploitation of Operational Missions (SEOM) and Climate Change Initiative (CCI), several R&D activities are preparing the exploitation of the Sentinel-2 mission towards reliable measurements and monitoring of e.g. Essential Climate Variables and indicators for the Sustainable Development Goals. Early Sentinel-2 results will be presented related to a range of applications and scientific domains such as agricultural monitoring at national scale (DUE Sen2Agri), wetland extent and condition over African Ramsar sites (DUE GlobWetland-Africa), land cover mapping for climate change (CCI Land Cover), national land monitoring (Cadaster-Env), forest degradation (DUE ForMoSa), urban mapping (DUE EO4Urban), in-land water quality (DUE SPONGE), map of Mediterranean aquaculture (DUE SMART) and coral reef habitat mapping (SEOM S2-4Sci Coral). The above-mentioned activities are only a few examples from the very active international land imaging community building on the long-term Landsat and Spot heritage and knowledge.

Field Testing Of An Expert Model: Can The Model Predict Habitat Potential For Saltmarsh Birds?

EPA Science Inventory

Salt marshes are valuable resources, which provide numerous ecosystem services, including flood protection, fish nursery habitat, and nesting habitat for a number of threatened and endangered species. At the present time, due primarily to coastal development and sea level rise,...

Non-Markovian dynamics of a qubit due to single-photon scattering in a waveguide

NASA Astrophysics Data System (ADS)

Fang, Yao-Lung L.; Ciccarello, Francesco; Baranger, Harold U.

2018-04-01

We investigate the open dynamics of a qubit due to scattering of a single photon in an infinite or semi-infinite waveguide. Through an exact solution of the time-dependent multi-photon scattering problem, we find the qubit's dynamical map. Tools of open quantum systems theory allow us then to show the general features of this map, find the corresponding non-Linbladian master equation, and assess in a rigorous way its non-Markovian nature. The qubit dynamics has distinctive features that, in particular, do not occur in emission processes. Two fundamental sources of non-Markovianity are present: the finite width of the photon wavepacket and the time delay for propagation between the qubit and the end of the semi-infinite waveguide.

[Limits of conventional oral and transdermal medication in Parkinson's disease].

PubMed

García-Ruiz, Pedro J; Luquin, M Rosario

2012-01-01

At the present time, we have effective and potent antiparkinsonian drugs available which allow patients to have an acceptable functional capacity during the early years of Parkinson's disease. Yet, as time goes by, motor and functional deterioration develop, partly due to the presence of motor and non-motor complications. The conventional medication is unable to provide an adequate response if the motor fluctuations are beyond 3-4 hours of duration. At this point, it is reasonable to consider other therapies; among them subcutaneous apomorphine injection must be taken into account due to its simplicity and efficacy and later on, subcutaneous apomorphine infusion. Apomorphine is a very effective and clearly underused drug in the treatment of advanced Parkinson's disease.

Optimal timing of antenatal corticosteroids in women with bleeding placenta previa or low-lying placenta.

PubMed

Alsayegh, Eman; Barrett, Jon; Melamed, Nir

2018-01-11

Administrating a single course of antenatal corticosteroids to women at risk of preterm birth between 24 and 34 weeks of gestation has been shown to decrease neonatal morbidity and mortality. There is evidence that the optimal timing for the administration of antenatal corticosteroids is within 1-7 days before birth as the effect of antenatal corticosteroids has been shown to decline 7 days after administration. Therefore, given that antenatal corticosteroids are the single most effective intervention in cases of preterm birth, efforts should be made to optimize the timing of administration of antenatal corticosteroids. To test the hypothesis that the timing of antenatal corticosteroids in women with vaginal bleeding due to placenta previa or low-lying placenta can be optimized by identifying women at low risk of imminent delivery. This was a retrospective cohort study of all women admitted to a tertiary referral center at 24-34 weeks' gestation with vaginal bleeding due to placenta previa or low-lying placenta between 2003 and 2014. Multivariable logistic regression analysis was used to identify factors that are independently associated with delivery within 14 days from admission. A total of 202 women who met the inclusion criteria were admitted with vaginal bleeding in the presence of placenta previa or low-lying placenta during the study period, of whom 31 (15.3%) and 44 (21.8%) gave birth within 7 and 14 days from admission, respectively. The following factors were independently associated with delivery within 14 days from admission: complete placenta previa (odds (OR) 3.57, 95%CI 1.57-9.03), severe bleeding at presentation (OR 17.14, 95%CI 2.92-100.70), uterine contractions at presentation (OR 6.02, 95%CI 1.91-19.00), and cervical length <25 mm at presentation (OR 6.33, 95%CI 1.37-29.11). A predictive test based on the presence of ≥1 of these risk factors was associated with a sensitivity of 90.9% and a negative predictive value of 94.6% for delivery within 14 days of presentation. In women presenting with vaginal bleeding due to placenta previa or low-lying placenta, it seems possible to identify a subgroup of women in whom the likelihood of delivery within 14 days is low. This information may allow for selective (rather than routine) administration of antenatal corticosteroids in this scenario, and may thereby contribute to the optimization of the timing of administration of antenatal corticosteroids.

Preventive overhaul time for power transformers

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

Sarmadi, M.; Rouhi, J.; Fayyaz, A.

Power transformers are the major piece of equipment in high-voltage substations. A considerable number of these transformers exist in Iran`s integrated network. Due to the climate diversity and improper usage, many of these transformers age rapidly, suffer failure and are taken out of service before half their useful life. At the present time the utility companies have no specific time-frame and plan for preventive overhaul. Detection of preventive overhaul time will increase the remaining life of transformers and improve the reliability of substations. An exact check of the remaining lifetime of transformers is not yet possible by available diagnostic techniques.more » In this paper, the authors present a method of identifying the right time for preventive overhaul in 63 kV power transformers. This method is developed based on 25 year transformer performance records in Northern Iran (subtropical climate) and with the utilization of studies done by electrical engineering communities world-wide.« less

Modern Era Retrospective-analysis for Research and Applications (MERRA) Global Water and Energy Budgets

NASA Technical Reports Server (NTRS)

Bosilovich, Michael G.; Robertson, Franklin R.; Chen, Junye

2008-01-01

The Modern. Era Retrospective-analysis for Research and Applications (MERRA) reanalyses has produced several years of data, on the way to a completing. the 1979-present modern satellite era. Here, we present a preliminary evaluation of those years currently available, includin g comparisons with the existing long reanalyses (ERA40, JRA25 and NCE P I and II) as well as with global data sets for the water and energy cycle Time series shows that the MERRA budgets can change with some of the variations in observing systems. We will present all terms of the budgets in MERRA including the time rates of change and analysis increments (tendency due to the analysis of observations)

MSL: A Measure to Evaluate Three-dimensional Patterns in Gene Expression Data

PubMed Central

Gutiérrez-Avilés, David; Rubio-Escudero, Cristina

2015-01-01

Microarray technology is highly used in biological research environments due to its ability to monitor the RNA concentration levels. The analysis of the data generated represents a computational challenge due to the characteristics of these data. Clustering techniques are widely applied to create groups of genes that exhibit a similar behavior. Biclustering relaxes the constraints for grouping, allowing genes to be evaluated only under a subset of the conditions. Triclustering appears for the analysis of longitudinal experiments in which the genes are evaluated under certain conditions at several time points. These triclusters provide hidden information in the form of behavior patterns from temporal experiments with microarrays relating subsets of genes, experimental conditions, and time points. We present an evaluation measure for triclusters called Multi Slope Measure, based on the similarity among the angles of the slopes formed by each profile formed by the genes, conditions, and times of the tricluster. PMID:26124630

Recent advances in MRI technology: Implications for image quality and patient safety

PubMed Central

Sobol, Wlad T.

2012-01-01

Recent advances in MRI technology are presented, with emphasis on how this new technology impacts clinical operations (better image quality, faster exam times, and improved throughput). In addition, implications for patient safety are discussed with emphasis on the risk of patient injury due to either high local specific absorption rate (SAR) or large cumulative energy doses delivered during long exam times. Patient comfort issues are examined as well. PMID:23961024

Zero-crossing detector with sub-microsecond jitter and crosstalk

NASA Technical Reports Server (NTRS)

Dick, G. John; Kuhnle, Paul F.; Sydnor, Richard L.

1990-01-01

A zero-crossing detector (ZCD) was built and tested with a new circuit design which gives reduced time jitter compared to previous designs. With the new design, time jitter is reduced for the first time to a value which approaches that due to noise in the input amplifying stage. Additionally, with fiber-optic transmission of the output signal, crosstalk between units has been eliminated. The measured values are in good agreement with circuit noise calculations and approximately ten times lower than that for ZCD's presently installed in the JPL test facility. Crosstalk between adjacent units was reduced even more than the jitter.

Millennial strain partitioning revealed by 36Cl cosmogenic data on active bedrock fault scarps from Abruzzo, Italy

NASA Astrophysics Data System (ADS)

Gregory, Laura; Roberts, Gerald; Cowie, Patience; Wedmore, Luke; McCaffrey, Ken; Shanks, Richard; Zijerveld, Leo; Phillips, Richard

2017-04-01

In zones of distributed continental faulting, it is critical to understand how slip is partitioned onto brittle structures over both long-term millennial time scales and shorter-term individual earthquake cycles. Measuring earthquake slip histories on different timescales is challenging due to earthquake repeat-times being longer or similar to historical earthquake records, and a paucity of data on fault activity covering millennial to Quaternary scales in detail. Cosmogenic isotope analyses from bedrock fault scarps have the potential to bridge the gap, as these datasets track the exposure of fault planes due to earthquakes with millennial resolution. In this presentation, we present new 36Cl data combined with historical earthquake records to document orogen-wide changes in the distribution of seismicity on millennial timescales in Abruzzo, central Italy. Seismic activity due to extensional faulting was concentrated on the northwest side of the mountain range during the historical period, or since approximately the 14th century. Seismicity is more limited on the southwest side of Abruzzo during historical times. This pattern has led some to suggest that faults on the southwest side of Abruzzo are not active, however clear fault scarps cutting Holocene-aged slopes are well preserved across the whole of the orogen. These scarps preserve an excellent record of Late Pleistocene to Holocene earthquake activity, which can be quantified using cosmogenic isotopes that track the exposure of the bedrock fault scarps. 36Cl accumulates in the fault scarps as the plane is progressively exhumed by earthquakes and the concentration of 36Cl measured up the fault plane reflects the rate and patterns of slip. We utilise Bayesian modelling techniques to estimate slip histories based on the cosmogenic data. Each sampling site is carefully characterised using LiDAR and GPR to ensure that fault plane exposure is due to slip during earthquakes and not sediment transport processes. In this presentation we will focus on new data from faults located across-strike in Abruzzo. Many faults in Abruzzo demonstrate slip rate variability on millennial timescales, with relatively fast slip interspersed between quiescent periods. We show that heightened activity is co-located and spatially migrates across Abruzzo over time. We highlight the importance of understanding this dynamic fault behaviour of migrating seismic activity, and in particular how our research is relevant to the 2016 Amatrice-Vettore seismic sequence in central Italy.

Early or delayed surgical treatment in compound limb fractures due to high velocity missile injuries: a 5-year retrospective study from Medical City in Baghdad.

PubMed

Al-Hilli, Ali Bakir; Salih, Dheyaa Saeed

2010-01-01

Compound limb fractures due to high-velocity missiles are complex and usually associated with multiple other injuries. These can occur in both military and civilian settings. High-velocity missiles are presently used by terrorists worldwide. Early surgical debridement and skeletal fixation are the gold standards in managing these injuries, but data supporting these recommendations are lacking. Our aim was to determine the relationship between time (the time of injury to the time of surgical treatment) and the rate of deep infection in patients treated in Medical City, Baghdad, Iraq due to terrorist activity from 2004-2008. This is a retrospective review of a series of open limb fractures. A total of 102 civilian patients with 114 limb fractures due to high-velocity missile injuries were selected for this study from Medical City records. Patients were followed in the outpatient department in Medical City Teaching Complex both clinically and radiologically. Surgical treatment was accomplished in less than six hours from time of injury in group A (55 fractures, 48.4%) and more than six hours in group B (59 fractures, 51.7%). The infection rate for group A was 30.9% and group B was 23.7%. A very high infection rate was noted for these injuries, and there was no increase in the rate of deep infection in patients treated more than six hours after the injury.

The Interpersonal Theory of Suicide

ERIC Educational Resources Information Center

Van Orden, Kimberly A.; Witte, Tracy K.; Cukrowicz, Kelly C.; Braithwaite, Scott R.; Selby, Edward A.; Joiner, Thomas E., Jr.

2010-01-01

Suicidal behavior is a major problem worldwide and, at the same time, has received relatively little empirical attention. This relative lack of empirical attention may be due in part to a relative absence of theory development regarding suicidal behavior. The current article presents the interpersonal theory of suicidal behavior. We propose that…

The Handling of Missing Binary Data in Language Research

ERIC Educational Resources Information Center

Pichette, François; Béland, Sébastien; Jolani, Shahab; Lesniewska, Justyna

2015-01-01

Researchers are frequently confronted with unanswered questions or items on their questionnaires and tests, due to factors such as item difficulty, lack of testing time, or participant distraction. This paper first presents results from a poll confirming previous claims (Rietveld & van Hout, 2006; Schafer & Graham, 2002) that data…

Transformative Learning Following Job Loss: A Dissertation Renewal

ERIC Educational Resources Information Center

Benway, Robert

2017-01-01

This study renews a doctoral dissertation written in 2003 on transformative learning following job loss. An abbreviated literature review compares corporate and worker circumstances from the original study to the present time. Findings show that corporations choose reductions in force due to pressure from investors instead of productivity, and…

Methods of Oil Detection in Response to the Deepwater Horizon Oil Spill

EPA Science Inventory

Detecting oil in the northern Gulf of Mexico following the Deepwater Horizon oil spill presented unique challenges due to the spatial and temporal extent of the spill and the subsequent dilution of oil in the environment. Over time, physical, chemical, and biological processes a...

Quantitative laser speckle flowmetry of the in vivo microcirculation using sidestream dark field microscopy

PubMed Central

Nadort, Annemarie; Woolthuis, Rutger G.; van Leeuwen, Ton G.; Faber, Dirk J.

2013-01-01

We present integrated Laser Speckle Contrast Imaging (LSCI) and Sidestream Dark Field (SDF) flowmetry to provide real-time, non-invasive and quantitative measurements of speckle decorrelation times related to microcirculatory flow. Using a multi exposure acquisition scheme, precise speckle decorrelation times were obtained. Applying SDF-LSCI in vitro and in vivo allows direct comparison between speckle contrast decorrelation and flow velocities, while imaging the phantom and microcirculation architecture. This resulted in a novel analysis approach that distinguishes decorrelation due to flow from other additive decorrelation sources. PMID:24298399

Time-resolved studies of energy transfer from meso-tetrakis(N-methylpyridinium-4-yl)- porphyrin to 3,3'-diethyl-2,2'-thiatricarbocyanine iodide along deoxyribonucleic acid Chain.

PubMed

Kakiuchi, Toshifumi; Ito, Fuyuki; Nagamura, Toshihiko

2008-04-03

The excitation energy transfer from meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) to 3,3'-diethyl-2,2'-thiatricarbocyanine iodide (DTTCI) along the deoxyribonucleic acid (DNA) double strand was investigated by the steady-state absorption and fluorescence measurements and time-resolved fluorescence measurements. The steady-state fluorescence spectra showed that the near-infrared fluorescence of DTTCI was strongly enhanced up to 86 times due to the energy transfer from the excited TMPyP molecule in DNA buffer solution. Furthermore, we elucidated the mechanism of fluorescence quenching and enhancement by the direct observation of energy transfer using the time-resolved measurements. The fluorescence quenching of TMPyP chiefly consists of a static component due to the formation of complex and dynamic components due to the excitation energy transfer. In a heterogeneous one-dimensional system such as a DNA chain, it was proved that the energy transfer process only carries out within the critical distance based on the Förster theory and within a threshold value estimated from the modified Stern-Volmer equation. The present results showed that DNA chain is one of the most powerful tools for nanoassemblies and will give a novel concepts of material design.

Creep and shrinkage effects on integral abutment bridges

NASA Astrophysics Data System (ADS)

Munuswamy, Sivakumar

Integral abutment bridges provide bridge engineers an economical design alternative to traditional bridges with expansion joints owing to the benefits, arising from elimination of expensive joints installation and reduced maintenance cost. The superstructure for integral abutment bridges is cast integrally with abutments. Time-dependent effects of creep, shrinkage of concrete, relaxation of prestressing steel, temperature gradient, restraints provided by abutment foundation and backfill and statical indeterminacy of the structure introduce time-dependent variations in the redundant forces. An analytical model and numerical procedure to predict instantaneous linear behavior and non-linear time dependent long-term behavior of continuous composite superstructure are developed in which the redundant forces in the integral abutment bridges are derived considering the time-dependent effects. The redistributions of moments due to time-dependent effects have been considered in the analysis. The analysis includes nonlinearity due to cracking of the concrete, as well as the time-dependent deformations. American Concrete Institute (ACI) and American Association of State Highway and Transportation Officials (AASHTO) models for creep and shrinkage are considered in modeling the time dependent material behavior. The variations in the material property of the cross-section corresponding to the constituent materials are incorporated and age-adjusted effective modulus method with relaxation procedure is followed to include the creep behavior of concrete. The partial restraint provided by the abutment-pile-soil system is modeled using discrete spring stiffness as translational and rotational degrees of freedom. Numerical simulation of the behavior is carried out on continuous composite integral abutment bridges and the deformations and stresses due to time-dependent effects due to typical sustained loads are computed. The results from the analytical model are compared with the published laboratory experimental and field data. The behavior of the laterally loaded piles supporting the integral abutments is evaluated and presented in terms of the lateral deflection, bending moment, shear force and stress along the pile depth.

Acute auditory agnosia as the presenting hearing disorder in MELAS.

PubMed

Miceli, Gabriele; Conti, Guido; Cianfoni, Alessandro; Di Giacopo, Raffaella; Zampetti, Patrizia; Servidei, Serenella

2008-12-01

MELAS is commonly associated with peripheral hearing loss. Auditory agnosia is a rare cortical auditory impairment, usually due to bilateral temporal damage. We document, for the first time, auditory agnosia as the presenting hearing disorder in MELAS. A young woman with MELAS (A3243G mtDNA mutation) suffered from acute cortical hearing damage following a single stroke-like episode, in the absence of previous hearing deficits. Audiometric testing showed marked central hearing impairment and very mild sensorineural hearing loss. MRI documented bilateral, acute lesions to superior temporal regions. Neuropsychological tests demonstrated auditory agnosia without aphasia. Our data and a review of published reports show that cortical auditory disorders are relatively frequent in MELAS, probably due to the strikingly high incidence of bilateral and symmetric damage following stroke-like episodes. Acute auditory agnosia can be the presenting hearing deficit in MELAS and, conversely, MELAS should be suspected in young adults with sudden hearing loss.

Double whammy- acute splenic sequestration crisis in patient with aplastic crisis due to acute parvovirus infection.

PubMed

Minhas, Parminder S; K Virdi, Jaspreet; Patel, Rajeshkumar

2017-07-01

Splenic dysfunction is a major feature of sickle cell disease (SCD) and can manifest as acute splenic sequestration crisis (ASSC), which is the earliest life-threatening complication seen in patients with SCD. Aplastic crisis is another potentially deadly complication of sickle cell disease that develops when erythrocyte production temporarily drops. Infection with parvovirus B-19 frequently causes aplastic crises. These two complications are known to be mutually exclusive due to their classic presentation signs and symptoms but there have been few cases where a patient can have concomitant presentation of both phenomena, which can result in a fatal outcome. These few cases force us to rethink the etiology and subsequent management guidelines of these complications. We present to you a case of an unfortunate 23-year-old female who had both complications occurring at the same time, resulting in death.

Changes in academic adjustment and relational self-worth across the transition to middle school.

PubMed

Ryan, Allison M; Shim, Sungok Serena; Makara, Kara A

2013-09-01

Moving from elementary to middle school is a time of great transition for many early adolescents. The present study examined students' academic adjustment and relational self-worth at 6-month intervals for four time points spanning the transition from elementary school to middle school (N = 738 at time 1; 53 % girls; 54 % African American, 46 % European American). Grade point average (G.P.A.), intrinsic value for schoolwork, self-worth around teachers, and self-worth around friends were examined at every time point. The overall developmental trajectory indicated that G.P.A. and intrinsic value for schoolwork declined. The overall decline in G.P.A. was due to changes at the transition and across the first year in middle school. Intrinsic value declined across all time points. Self-worth around teachers was stable. The developmental trends were the same regardless of gender or ethnicity except for self-worth around friends, which was stable for European American students and increased for African American students due to an ascent at the transition into middle school. Implications for the education of early adolescents in middle schools are discussed.

Fluoroscopy-Guided Endoscopic Removal of Foreign Bodies.

PubMed

Kim, Junhwan; Ahn, Ji Yong; So, Seol; Lee, Mingee; Oh, Kyunghwan; Jung, Hwoon-Yong

2017-03-01

In most cases of ingested foreign bodies, endoscopy is the first treatment of choice. Moreover, emergency endoscopic removal is required for sharp and pointed foreign bodies such as animal or fish bones, food boluses, and button batteries due to the increased risks of perforation, obstruction, and bleeding. Here, we presented two cases that needed emergency endoscopic removal of foreign bodies without sufficient fasting time. Foreign bodies could not be visualized by endoscopy due to food residue; therefore, fluoroscopic imaging was utilized for endoscopic removal of foreign bodies in both cases.

Time delay measurement in the frequency domain

DOE PAGES

Durbin, Stephen M.; Liu, Shih -Chieh; Dufresne, Eric M.; ...

2015-08-06

Pump–probe studies at synchrotrons using X-ray and laser pulses require accurate determination of the time delay between pulses. This becomes especially important when observing ultrafast responses with lifetimes approaching or even less than the X-ray pulse duration (~100 ps). The standard approach of inspecting the time response of a detector sensitive to both types of pulses can have limitations due to dissimilar pulse profiles and other experimental factors. Here, a simple alternative is presented, where the frequency response of the detector is monitored versus time delay. Measurements readily demonstrate a time resolution of ~1 ps. Improved precision is possible bymore » simply extending the data acquisition time.« less

Working memory capacity and recall from long-term memory: Examining the influences of encoding strategies, study time allocation, search efficiency, and monitoring abilities.

PubMed

Unsworth, Nash

2016-01-01

The relation between working memory capacity (WMC) and recall from long-term memory (LTM) was examined in the current study. Participants performed multiple measures of delayed free recall varying in presentation duration and self-reported their strategy usage after each task. Participants also performed multiple measures of WMC. The results suggested that WMC and LTM recall were related, and part of this relation was due to effective strategy use. However, adaptive changes in strategy use and study time allocation were not related to WMC. Examining multiple variables with structural equation modeling suggested that the relation between WMC and LTM recall was due to variation in effective strategy use, search efficiency, and monitoring abilities. Furthermore, all variables were shown to account for individual differences in LTM recall. These results suggest that the relation between WMC and recall from LTM is due to multiple strategic factors operating at both encoding and retrieval. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Depletion Calculations Based on Perturbations. Application to the Study of a Rep-Like Assembly at Beginning of Cycle with TRIPOLI-4®.

NASA Astrophysics Data System (ADS)

Dieudonne, Cyril; Dumonteil, Eric; Malvagi, Fausto; M'Backé Diop, Cheikh

2014-06-01

For several years, Monte Carlo burnup/depletion codes have appeared, which couple Monte Carlo codes to simulate the neutron transport to deterministic methods, which handle the medium depletion due to the neutron flux. Solving Boltzmann and Bateman equations in such a way allows to track fine 3-dimensional effects and to get rid of multi-group hypotheses done by deterministic solvers. The counterpart is the prohibitive calculation time due to the Monte Carlo solver called at each time step. In this paper we present a methodology to avoid the repetitive and time-expensive Monte Carlo simulations, and to replace them by perturbation calculations: indeed the different burnup steps may be seen as perturbations of the isotopic concentration of an initial Monte Carlo simulation. In a first time we will present this method, and provide details on the perturbative technique used, namely the correlated sampling. In a second time the implementation of this method in the TRIPOLI-4® code will be discussed, as well as the precise calculation scheme a meme to bring important speed-up of the depletion calculation. Finally, this technique will be used to calculate the depletion of a REP-like assembly, studied at beginning of its cycle. After having validated the method with a reference calculation we will show that it can speed-up by nearly an order of magnitude standard Monte-Carlo depletion codes.

Combined immunodeficiency presenting with vaccine-associated paralytic poliomyelitis: a case report and narrative review of literature.

PubMed

Shaghaghi, Mohammadreza; Parvaneh, Nima; Ostad-Rahimi, Pouya; Fathi, Seyed Mohammad; Shahmahmoodi, Shohreh; Abolhassani, Hassan; Aghamohammadi, Asghar

2014-01-01

Neurologic abnormalities compatible with vaccine-related poliovirus infection (VAPP) may be a first presentation of some primary immunodeficient patients. The risk of VAPP rises from 1 case per 750 000 in normal population to 1 per 7000 times higher, particularly for persons with agammaglobulinemia and hypogammaglobulinemia. However, there is no appropriate estimation for VAPP occurrence in patients with cellular immunity defects. Herein we report a case of combined immunodeficiency with paralytic complication due to oral polio vaccine and we present a literature review on this topic.

Comment on ''The velocity field due to an oscillating plate in an Oldroyd-B fluid'' by C.C. Hopkins and J.R. de Bruyn [Can. J. Phys. 92, 533 (2014)

DOE PAGES

Christov, Ivan C.

2015-09-11

We correct certain errors and ambiguities in the recent pedagogical article by Hopkins and de Bruyn. The early-time asymptotics of the solution to the transient version of Stokes’ second problem for an Oldroyd-B fluid in a half-space is presented, as Appendix A, to complement the late-time asymptotics given by Hopkins and de Bruyn.

NOTE ON TRAVEL TIME SHIFTS DUE TO AMPLITUDE MODULATION IN TIME-DISTANCE HELIOSEISMOLOGY MEASUREMENTS

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

Nigam, R.; Kosovichev, A. G., E-mail: rakesh@quake.stanford.ed, E-mail: sasha@quake.stanford.ed

Correct interpretation of acoustic travel times measured by time-distance helioseismology is essential to get an accurate understanding of the solar properties that are inferred from them. It has long been observed that sunspots suppress p-mode amplitude, but its implications on travel times have not been fully investigated so far. It has been found in test measurements using a 'masking' procedure, in which the solar Doppler signal in a localized quiet region of the Sun is artificially suppressed by a spatial function, and using numerical simulations that the amplitude modulations in combination with the phase-speed filtering may cause systematic shifts ofmore » acoustic travel times. To understand the properties of this procedure, we derive an analytical expression for the cross-covariance of a signal that has been modulated locally by a spatial function that has azimuthal symmetry and then filtered by a phase-speed filter typically used in time-distance helioseismology. Comparing this expression to the Gabor wavelet fitting formula without this effect, we find that there is a shift in the travel times that is introduced by the amplitude modulation. The analytical model presented in this paper can be useful also for interpretation of travel time measurements for the non-uniform distribution of oscillation amplitude due to observational effects.« less

International benchmarking of longitudinal train dynamics simulators: results

NASA Astrophysics Data System (ADS)

Wu, Qing; Spiryagin, Maksym; Cole, Colin; Chang, Chongyi; Guo, Gang; Sakalo, Alexey; Wei, Wei; Zhao, Xubao; Burgelman, Nico; Wiersma, Pier; Chollet, Hugues; Sebes, Michel; Shamdani, Amir; Melzi, Stefano; Cheli, Federico; di Gialleonardo, Egidio; Bosso, Nicola; Zampieri, Nicolò; Luo, Shihui; Wu, Honghua; Kaza, Guy-Léon

2018-03-01

This paper presents the results of the International Benchmarking of Longitudinal Train Dynamics Simulators which involved participation of nine simulators (TABLDSS, UM, CRE-LTS, TDEAS, PoliTo, TsDyn, CARS, BODYSIM and VOCO) from six countries. Longitudinal train dynamics results and computing time of four simulation cases are presented and compared. The results show that all simulators had basic agreement in simulations of locomotive forces, resistance forces and track gradients. The major differences among different simulators lie in the draft gear models. TABLDSS, UM, CRE-LTS, TDEAS, TsDyn and CARS had general agreement in terms of the in-train forces; minor differences exist as reflections of draft gear model variations. In-train force oscillations were observed in VOCO due to the introduction of wheel-rail contact. In-train force instabilities were sometimes observed in PoliTo and BODYSIM due to the velocity controlled transitional characteristics which could have generated unreasonable transitional stiffness. Regarding computing time per train operational second, the following list is in order of increasing computing speed: VOCO, TsDyn, PoliTO, CARS, BODYSIM, UM, TDEAS, CRE-LTS and TABLDSS (fastest); all simulators except VOCO, TsDyn and PoliTo achieved faster speeds than real-time simulations. Similarly, regarding computing time per integration step, the computing speeds in order are: CRE-LTS, VOCO, CARS, TsDyn, UM, TABLDSS and TDEAS (fastest).

Making historic loss data comparable over time and place

NASA Astrophysics Data System (ADS)

Eichner, Jan; Steuer, Markus; Löw, Petra

2017-04-01

When utilizing historic loss data for present day risk assessment, it is necessary to make the data comparable over time and place. To achieve this, the assessment of costs from natural hazard events requires consistent and homogeneous methodologies for loss estimation as well as a robust treatment of loss data to estimate and/or reduce distorting effects due to a temporal bias in the reporting of small-scale loss events. Here we introduce Munich Re's NatCatSERVICE loss database and present a novel methodology of peril-specific normalization of the historic losses (to account for socio-economic growth of assets over time), and we introduce a metric of severity classification (called CatClass) that allows for a global comparison of impact severity across countries of different stages of economic development.

Breath Activity Monitoring With Wearable UWB Radars: Measurement and Analysis of the Pulses Reflected by the Human Body.

PubMed

Pittella, Erika; Pisa, Stefano; Cavagnaro, Marta

2016-07-01

Measurements of ultrawideband (UWB) pulses reflected by the human body are conducted to evidence the differences in the received signal time behaviors due to respiration phases, and to experimentally verify previously obtained numerical results on the body's organs responsible for pulse reflection. Two experimental setups are used. The first one is based on a commercially available impulse radar system integrated on a single chip, while the second one implements an indirect time-domain reflectometry technique using a vector network analyzer controlled by a LabVIEW virtual instrument running on a laptop. When the UWB source is placed close to the human body, a small reflection due to the lung boundaries is present in the received pulse well distanced in time from the reflection due to the air-skin interface; this reflection proved to be linked to the different respiration phases. The changes in the reflected pulse could be used to detect, through wearable radar systems, lung movements associated with the breath activity. The development of a wearable radar system is of great importance because it allows the breath activity sensing without interfering with the subject daily activities.

Space Network Time Distribution and Synchronization Protocol Development for Mars Proximity Link

NASA Technical Reports Server (NTRS)

Woo, Simon S.; Gao, Jay L.; Mills, David

2010-01-01

Time distribution and synchronization in deep space network are challenging due to long propagation delays, spacecraft movements, and relativistic effects. Further, the Network Time Protocol (NTP) designed for terrestrial networks may not work properly in space. In this work, we consider the time distribution protocol based on time message exchanges similar to Network Time Protocol (NTP). We present the Proximity-1 Space Link Interleaved Time Synchronization (PITS) algorithm that can work with the CCSDS Proximity-1 Space Data Link Protocol. The PITS algorithm provides faster time synchronization via two-way time transfer over proximity links, improves scalability as the number of spacecraft increase, lowers storage space requirement for collecting time samples, and is robust against packet loss and duplication which underlying protocol mechanisms provide.

Evaluation of the Modern Era Retrospective-Analysis for Research and Applications (MERRA) Global Water and Energy Budgets

NASA Technical Reports Server (NTRS)

Bosilovich, Michael G.; Robertson, F. R.; Chen, J.

2010-01-01

The Modern Era Retrospective-analysis for Research and Applications (MERRA) reanalyses has completed 27 years of data) soon to be caught up to present. Here) we present an evaluation of those years currently available) including comparisons with the existing long reanalyses (ERA40) JRA25 and NCEP I and II) as well as with global data sets for the water and energy cycle. Time series shows that the MERRA budgets can change with some of the variations in observing systems, but that the magnitude of energy imbalance in the system is improved with more observations. We will present all terms of the budgets in MERRA including the time rates of change and analysis increments (tendency due to the analysis of observations).

Future electro-optical sensors and processing in urban operations

NASA Astrophysics Data System (ADS)

Grönwall, Christina; Schwering, Piet B.; Rantakokko, Jouni; Benoist, Koen W.; Kemp, Rob A. W.; Steinvall, Ove; Letalick, Dietmar; Björkert, Stefan

2013-10-01

In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of local, distributed and centralized processing are proposed. In this way one can match processing functionality to the required power, and available communication systems data rates, to obtain the desired reaction times. In the study, three priority scenarios were defined. For these scenarios, present-day and future sensors and signal processing technologies were studied. The priority scenarios were camp protection, patrol and house search. A method for analyzing information quality in single and multi-sensor systems has been applied. A method for estimating reaction times for transmission of data through the chain of command has been proposed and used. These methods are documented and can be used to modify scenarios, or be applied to other scenarios. Present day data processing is organized mainly locally. Very limited exchange of information with other platforms is present; this is performed mainly at a high information level. Main issues that arose from the analysis of present-day systems and methodology are the slow reaction time due to the limited field of view of present-day sensors and the lack of robust automated processing. Efficient handover schemes between wide and narrow field of view sensors may however reduce the delay times. The main effort in the study was in forecasting the signal processing of EO-sensors in the next ten to twenty years. Distributed processing is proposed between hand-held and vehicle based sensors. This can be accompanied by cloud processing on board several vehicles. Additionally, to perform sensor fusion on sensor data originating from different platforms, and making full use of UAV imagery, a combination of distributed and centralized processing is essential. There is a central role for sensor fusion of heterogeneous sensors in future processing. The changes that occur in the urban operations of the future due to the application of these new technologies will be the improved quality of information, with shorter reaction time, and with lower operator load.

LOADS: a computer program for determining the shear, bending moment and axial loads for fuselage type structures

NASA Technical Reports Server (NTRS)

Nolte, W. E.

1976-01-01

LOADS determines rigid body vehicle shears, bending moments and axial loads on a space vehicle due to aerodynamic loads and propellant inertial loads. An example hand calculation is presented and was used to check LOADS. A brief description of the program and the equations used are presented. LOADS is operational on the Univac 1110, occupies 10505 core and typically takes less than one(1) second of CAU time to execute.

Recurrent rhabdomyolysis in a child. Case presentation.

PubMed

Ertuğrul, Sabahattin; Yolbaş, İlyas; Aktar, Fesih; Yılmaz, Kamil; Tekin, Recep

2016-06-01

Viral myositis associated with infections rarely may cause rhabdomyolysis. There is no any pediatric case with severe recurrent rhabdomyolysis triggered by infections in the literature. We reported a two-year-old boy who was hospitalized three times due to severe rhabdomyolysis associated with viral myositis in the winter months. This is the first child case presentation with severe rhabdomyolysis triggered by infections. Prednisolone and intravenous immunoglobulin treatments were ineffective in this case. Sociedad Argentina de Pediatría.

Annoyance due to railway vibration at different times of the day.

PubMed

Peris, Eulalia; Woodcock, James; Sica, Gennaro; Moorhouse, Andrew T; Waddington, David C

2012-02-01

The time of day when vibration occurs is considered as a factor influencing the human response to vibration. The aim of the present paper is to identify the times of day during which railway vibration causes the greatest annoyance, to measure the differences between annoyance responses for different time periods and to obtain estimates of the time of day penalties. This was achieved using data from case studies comprised of face-to-face interviews and internal vibration measurements (N=755). Results indicate that vibration annoyance differs with time of day and that separate time of day weights can be applied when considering exposure-response relationships from railway vibration in residential environments. © 2012 Acoustical Society of America

Pretest reference calculation for the Heated Axisymmetric Pillar (WIPP Room H in situ experiment)

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

Morgan, H.S.; Stone, C.M.

A pretest reference calculation for the Heated Axisymmetric Pillar or Room H experiment is presented in this report. The Heated Axisymmetric Pillar is one of several large scale in situ experiments currently under construction near Carlsbad, New Mexico, at the site of the Waste Isolation Pilot Plant (WIPP). This test is an intermediate step in validating numerical techniques for design and performance calculations for radioactive waste repositories in salt. The test consists of a cylindrically shaped pillar, centrally located in an annular drift, which is uniformly heated by blanket heaters. These heaters produce a thermal output of 135 W/m/sup 2/.more » This load will be supplied for a period of three years. Room H is heavily instrumented for monitoring both temperature increases due to the thermal loading and deformations due to creep of the salt. Data from the experiment are not available at the present time, but the measurements for Room H will eventually be compared to the calculation presented in this report to assess and improve thermal and mechanical modeling capabilities for the WIPP. The thermal/structural model used in the calculation represents the state of the art at the present time. A large number of plots are included since an appropriate result is required for every Room H gauge location. 56 refs., 97 figs., 4 tabs.« less

A general model for attitude determination error analysis

NASA Technical Reports Server (NTRS)

Markley, F. Landis; Seidewitz, ED; Nicholson, Mark

1988-01-01

An overview is given of a comprehensive approach to filter and dynamics modeling for attitude determination error analysis. The models presented include both batch least-squares and sequential attitude estimation processes for both spin-stabilized and three-axis stabilized spacecraft. The discussion includes a brief description of a dynamics model of strapdown gyros, but it does not cover other sensor models. Model parameters can be chosen to be solve-for parameters, which are assumed to be estimated as part of the determination process, or consider parameters, which are assumed to have errors but not to be estimated. The only restriction on this choice is that the time evolution of the consider parameters must not depend on any of the solve-for parameters. The result of an error analysis is an indication of the contributions of the various error sources to the uncertainties in the determination of the spacecraft solve-for parameters. The model presented gives the uncertainty due to errors in the a priori estimates of the solve-for parameters, the uncertainty due to measurement noise, the uncertainty due to dynamic noise (also known as process noise or measurement noise), the uncertainty due to the consider parameters, and the overall uncertainty due to all these sources of error.

Replantation surgery in Quebec: The bottlenecks to rapid care

PubMed Central

Borsuk, Daniel E; Zadeh, Teanoosh; Lee, Chen; Moore, Karl; Tan, Grace

2006-01-01

INTRODUCTION Time delays resulting in prolonged ischemia have a significant impact on the successful reattachment of amputated body parts. No studies have addressed the issues surrounding delays from the time of the accident to the start of replantation surgery. The present paper identifies the bottlenecks that prolong the time before patients are able to gain access to a replant team. METHODS A total of 50 patients underwent microsurgical replantation, because of traumatic amputation, at a university-based hospital from 1996 to 2003. The charts were analyzed to ascertain individual time intervals from the onset of injury until the beginning of replant surgery. RESULTS The average length of time for patients who came directly to the replant centre was 3 h 40 min before surgery began. In contrast, for those referred from outlying hospitals, the elapsed time was 6 h 21 min. CONCLUSIONS Two major bottlenecks were found. First, for patients who were referred from other health centres, delays were due to a lack of information as to where patients could receive appropriate replant surgery. Second, delays at the replant centre were primarily due to insufficient physical and human resources in the operating room. PMID:19554107

Shock timing measurements and analysis in deuterium-tritium-ice layered capsule implosions on NIF

NASA Astrophysics Data System (ADS)

Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Hohenberger, M.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.

2014-02-01

Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion implosions [Boehly et al., Phys. Rev. Lett. 106, 195005 (2011); Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. Comparison of the data with simulation shows good agreement for the timing of the first three shocks, but reveals a considerable discrepancy in the timing of the 4th shock in DT ice layered implosions. Electron preheat is examined as a potential cause of the observed discrepancy in the 4th shock timing.

Starting Life Over--Working with the Head Injured: The Case of Randall.

ERIC Educational Resources Information Center

Bostwick, Tracy

1993-01-01

Presents case of engineering college student who, after automobile accident, three months in coma, and four years of rehabilitation therapy, is seeking career counseling due to his frustrations with obtaining full-time professional employment. Notes that client had difficulty remembering new information; was physically slow; was mentally slower…

Experiences of Computer Science Curriculum Design: A Phenomenological Study

ERIC Educational Resources Information Center

Sloan, Arthur; Bowe, Brian

2015-01-01

This paper presents a qualitative study of 12 computer science lecturers' experiences of curriculum design of several degree programmes during a time of transition from year-long to semesterised courses, due to institutional policy change. The background to the study is outlined, as are the reasons for choosing the research methodology. The main…

Space and Power in the Ivory Tower: Effective Space Management and Decision Making

ERIC Educational Resources Information Center

Blanchette, Sandra

2012-01-01

At a time when there are enormous economic pressures on campuses to use resources effectively, space being one of these resources, the academic culture of shared governance, with its fragmented roles for decision making, presents additional challenges. These roles are fragmented due to independent faculty and administrative action. They are…

Nonrelativistic Contribution to Mercury's Perihelion Precession.

ERIC Educational Resources Information Center

Price, Michael P.; Rush, William F.

1979-01-01

Presents a calculation of the precession of the perihelion of Mercury due to the perturbations from the outer planets. The time-average effect of each planet is calculated by replacing that planet with a ring of linear mass density equal to the mass of the planet divided by the circumference of its orbit. (Author/GA)

Three-dimensional modeling of the cochlea by use of an arc fitting approach.

PubMed

Schurzig, Daniel; Lexow, G Jakob; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S

2016-12-01

A cochlea modeling approach is presented allowing for a user defined degree of geometry simplification which automatically adjusts to the patient specific anatomy. Model generation can be performed in a straightforward manner due to error estimation prior to the actual generation, thus minimizing modeling time. Therefore, the presented technique is well suited for a wide range of applications including finite element analyses where geometrical simplifications are often inevitable. The method is presented for n=5 cochleae which were segmented using a custom software for increased accuracy. The linear basilar membrane cross sections are expanded to areas while the scalae contours are reconstructed by a predefined number of arc segments. Prior to model generation, geometrical errors are evaluated locally for each cross section as well as globally for the resulting models and their basal turn profiles. The final combination of all reconditioned features to a 3D volume is performed in Autodesk Inventor using the loft feature. Due to the volume generation based on cubic splines, low errors could be achieved even for low numbers of arc segments and provided cross sections, both of which correspond to a strong degree of model simplification. Model generation could be performed in a time efficient manner. The proposed simplification method was proven to be well suited for the helical cochlea geometry. The generated output data can be imported into commercial software tools for various analyses representing a time efficient way to create cochlea models optimally suited for the desired task.

Corneal tissue water content mapping with THz imaging: preliminary clinical results (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sung, Shijun; Bajwa, Neha; Deng, Sophie X.; Taylor, Zachary; Grundfest, Warren

2016-03-01

Well-regulated corneal water content is critical for ocular health and function and can be adversely affected by a number of diseases and injuries. Current clinical practice limits detection of unhealthy corneal water content levels to central corneal thickness measurements performed by ultrasound or optical coherence tomography. Trends revealing increasing or decreasing corneal thickness are fair indicators of corneal water content by individual measurements are highly inaccurate due to the poorly understood relationship between corneal thickness and natural physiologic variation. Recently the utility of THz imaging to accuarately measure corneal water content has been explored on with rabbit models. Preliminary experiments revealed that contact with dielectric windows confounded imaging data and made it nearly impossible to deconvolve thickness variations due to contact from thickness variations due to water content variation. A follow up study with a new optical design allowed the acquisition of rabbit data and the results suggest that the observed, time varying contrast was due entirely to the water dynamics of the cornea. This paper presents the first ever in vivo images of human cornea. Five volunteers with healthy cornea were recruited and their eyes were imaged three times over the course of a few minutes with our novel imaging system. Noticeable changes in corneal reflectivity were observed and attributed to the drying of the tear film. The results suggest that clinically compatible, non-contact corneal imaging is feasible and indicate that signal acquired from non-contact imaging of the cornea is a complicated coupling of stromal water content and tear film.

Real-time Optical Coherence Tomography Incorporated in the Operating Microscope during Cataract Surgery.

PubMed

Almutlak, Mohammed A; Aloniazan, Turki; May, William

2017-01-01

A 55-year-old male presented with reduced vision due to senile cataract. The patient consented to undergo real-time intraoperative anterior segment-optical coherence tomography (AS-OCT) during phacoemulsification with intraocular lens (IOL) implantation. Images were captured at various points during the surgery. The use of AS-OCT incorporated into the surgical microscope was evaluated as an adjunct to cataract surgery. We were able to successfully evaluate, in real-time, wound architecture, the attachment of Descemet's membrane, the posterior capsule, and IOL position. Real-time AS-OCT can be used to proactively address potential complications and verify IOL placement intraoperatively.

Urethrocutaneous fistulae after hypospadias repair: When do they occur?

PubMed

Liao, Adelene Y; Smith, Grahame Hh

2016-05-01

The aim is to determine the incidence and timing of urethrocutaneous fistula diagnosis after hypospadias surgery. A retrospective review of all patients who had both initial hypospadias surgery and subsequent fistula repair from 1995 to 2012. A comparison was made between patients who had an initial onlay island flap procedure and those who had a tubularised incised plate repair. Patient age at initial surgery ranged from 6 months to 16 years of age. The median time to fistula presentation was 8.5 months with a range of less than 1 month to 13.9 years post-hypospadias surgery. The median time to fistula repair was 17 months. The overall fistula rate was 8%. There was no significant difference between the rates of fistulae for onlay island flap (9%) versus tubularised incised plate procedure (7%). Urethrocutaneous fistulae can present many years after the original hypospadias repair. The majority are diagnosed within the first year after surgery. Rates of fistulae are probably underreported due to short follow-up, but more importantly, due to patients transferring to other surgeons for fistula repair. © 2016 The Author Journal of Paediatrics and Child Health © 2016 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Contaminant attenuation by shallow aquifer systems under steady flow

NASA Astrophysics Data System (ADS)

Soltani, S. S.; Cvetkovic, V.

2017-10-01

We present a framework for analyzing advection-dominated solute transport and transformation in aquifer systems of boreal catchments that are typically shallow and rest on crystalline bedrock. A methodology is presented for estimating tracer discharge based on particle trajectories from recharge to discharge locations and computing their first passage times assuming that the flow pattern is approximately steady-state. Transformation processes can be included by solving one-dimensional reactive transport with randomized water travel time as the independent variable; the distribution of the travel times incorporates morphological dispersion (due to catchment geometry/topography) as well as macro-dispersion (due to heterogeneity of underlying hydraulic properties). The implementation of the framework is illustrated for the well characterized coastal catchment of Forsmark (Sweden). We find that macro-dispersion has a notable effect on attenuation even though the morphological dispersion is significantly larger. Preferential flow on the catchment scale is found to be considerable with only 5% of the Eulerian velocities contributing to transport over the simulation period of 375 years. Natural attenuation is illustrated as a simple (linear decay) transformation process. Simulated natural attenuation can be estimated analytically reasonably well by using basic hydrological and structural information, the latter being the pathway length distribution and average aquifer depth to the bedrock.

HMI Data Driven Magnetohydrodynamic Model Predicted Active Region Photospheric Heating Rates: Their Scale Invariant, Flare Like Power Law Distributions, and Their Possible Association With Flares

NASA Technical Reports Server (NTRS)

Goodman, Michael L.; Kwan, Chiman; Ayhan, Bulent; Shang, Eric L.

2017-01-01

There are many flare forecasting models. For an excellent review and comparison of some of them see Barnes et al. (2016). All these models are successful to some degree, but there is a need for better models. We claim the most successful models explicitly or implicitly base their forecasts on various estimates of components of the photospheric current density J, based on observations of the photospheric magnetic field B. However, none of the models we are aware of compute the complete J. We seek to develop a better model based on computing the complete photospheric J. Initial results from this model are presented in this talk. We present a data driven, near photospheric, 3 D, non-force free magnetohydrodynamic (MHD) model that computes time series of the total J, and associated resistive heating rate in each pixel at the photosphere in the neutral line regions (NLRs) of 14 active regions (ARs). The model is driven by time series of B measured by the Helioseismic & Magnetic Imager (HMI) on the Solar Dynamics Observatory (SDO) satellite. Spurious Doppler periods due to SDO orbital motion are filtered out of the time series of B in every AR pixel. Errors in B due to these periods can be significant.

Transition-Metal-Doped p-Type ZnO Nanoparticle-Based Sensory Array for Instant Discrimination of Explosive Vapors.

PubMed

Qu, Jiang; Ge, Yuru; Zu, Baiyi; Li, Yuxiang; Dou, Xincun

2016-03-09

The development of portable, real-time, and cheap platforms to monitor ultratrace levels of explosives is of great urgence and importance due to the threat of terrorism attacks and the need for homeland security. However, most of the previous chemiresistor sensors for explosive detection are suffering from limited responses and long response time. Here, a transition-metal-doping method is presented to remarkably promote the quantity of the surface defect states and to significantly reduce the charge transfer distance by creating a local charge reservoir layer. Thus, the sensor response is greatly enhanced and the response time is remarkably shortened. The resulting sensory array can not only detect military explosives, such as, TNT, DNT, PNT, PA, and RDX with high response, but also can fully distinguish some of the improvised explosive vapors, such as AN and urea, due to the huge response reaching to 100%. Furthermore, this sensory array can discriminate ppb-level TNT and ppt-level RDX from structurally similar and high-concentration interfering aromatic gases in less than 12 s. Through comparison with the previously reported chemiresistor or Schottky sensors for explosive detection, the present transition-metal-doping method resulting ZnO sensor stands out and undoubtedly challenges the best. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Helicopter Airborne Laser Positioning System (HALPS)

NASA Technical Reports Server (NTRS)

Eppel, Joseph C.; Christiansen, Howard; Cross, Jeffrey; Totah, Joseph

1990-01-01

The theory of operation, configuration, laboratory, and ground test results obtained with a helicopter airborne laser positioning system developed by Princeton University is presented. Unfortunately, due to time constraints, flight data could not be completed for presentation at this time. The system measures the relative position between two aircraft in three dimensions using two orthogonal fan-shaped laser beams sweeping across an array of four detectors. Specifically, the system calculates the relative range, elevation, and azimuth between an observation aircraft and a test helicopter with a high degree of accuracy. The detector array provides a wide field of view in the presence of solar interference due to compound parabolic concentrators and spectral filtering of the detector pulses. The detected pulses and their associated time delays are processed by the electronics and are sent as position errors to the helicopter pilot who repositions the aircraft as part of the closed loop system. Accuracies obtained in the laboratory at a range of 80 ft in the absence of sunlight were + or - 1 deg in elevation; +0.5 to -1.5 deg in azimuth; +0.5 to -1.0 ft in range; while elevation varied from 0 to +28 deg and the azimuth varied from 0 to + or - 45 deg. Accuracies in sunlight were approximately 40 deg (+ or - 20 deg) in direct sunlight.

Nonstationary time series prediction combined with slow feature analysis

NASA Astrophysics Data System (ADS)

Wang, G.; Chen, X.

2015-07-01

Almost all climate time series have some degree of nonstationarity due to external driving forces perturbing the observed system. Therefore, these external driving forces should be taken into account when constructing the climate dynamics. This paper presents a new technique of obtaining the driving forces of a time series from the slow feature analysis (SFA) approach, and then introduces them into a predictive model to predict nonstationary time series. The basic theory of the technique is to consider the driving forces as state variables and to incorporate them into the predictive model. Experiments using a modified logistic time series and winter ozone data in Arosa, Switzerland, were conducted to test the model. The results showed improved prediction skills.

Uncertainty Due to Unsteady Fluid/Structure Interaction for the Ares I Vehicle Traversing the Transonic Regime

NASA Technical Reports Server (NTRS)

Bartels, Robert E.

2012-01-01

Rapid reduced-order numerical models are being investigated as candidates to simulate the dynamics of a flexible launch vehicle during atmospheric ascent. There has also been the extension of these new approaches to include gust response. These methods are used to perform aeroelastic and gust response analyses at isolated Mach numbers. Such models require a method to time march through a succession of ascent Mach numbers. An approach is presented for interpolating reduced-order models of the unsteady aerodynamics at successive Mach numbers. The transonic Mach number range is considered here since launch vehicles can suffer the highest dynamic loads through this range. Realistic simulations of the flexible vehicle behavior as it traverses this Mach number range are presented. The response of the vehicle due to gusts is computed. Uncertainties in root mean square and maximum bending moment and crew module accelerations are presented due to assumed probability distributions in design parameters, ascent flight conditions, gusts. The primary focus is on the uncertainty introduced by modeling fidelity. It is found that an unsteady reduced order model produces larger excursions in the root mean square loading and accelerations than does a quasi-steady reduced order model.

A high-order gas-kinetic Navier-Stokes flow solver

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

Li Qibing, E-mail: lqb@tsinghua.edu.c; Xu Kun, E-mail: makxu@ust.h; Fu Song, E-mail: fs-dem@tsinghua.edu.c

2010-09-20

The foundation for the development of modern compressible flow solver is based on the Riemann solution of the inviscid Euler equations. The high-order schemes are basically related to high-order spatial interpolation or reconstruction. In order to overcome the low-order wave interaction mechanism due to the Riemann solution, the temporal accuracy of the scheme can be improved through the Runge-Kutta method, where the dynamic deficiencies in the first-order Riemann solution is alleviated through the sub-step spatial reconstruction in the Runge-Kutta process. The close coupling between the spatial and temporal evolution in the original nonlinear governing equations seems weakened due to itsmore » spatial and temporal decoupling. Many recently developed high-order methods require a Navier-Stokes flux function under piece-wise discontinuous high-order initial reconstruction. However, the piece-wise discontinuous initial data and the hyperbolic-parabolic nature of the Navier-Stokes equations seem inconsistent mathematically, such as the divergence of the viscous and heat conducting terms due to initial discontinuity. In this paper, based on the Boltzmann equation, we are going to present a time-dependent flux function from a high-order discontinuous reconstruction. The theoretical basis for such an approach is due to the fact that the Boltzmann equation has no specific requirement on the smoothness of the initial data and the kinetic equation has the mechanism to construct a dissipative wave structure starting from an initially discontinuous flow condition on a time scale being larger than the particle collision time. The current high-order flux evaluation method is an extension of the second-order gas-kinetic BGK scheme for the Navier-Stokes equations (BGK-NS). The novelty for the easy extension from a second-order to a higher order is due to the simple particle transport and collision mechanism on the microscopic level. This paper will present a hierarchy to construct such a high-order method. The necessity to couple spatial and temporal evolution nonlinearly in the flux evaluation can be clearly observed through the numerical performance of the scheme for the viscous flow computations.« less

Ultra wide-band localization and SLAM: a comparative study for mobile robot navigation.

PubMed

Segura, Marcelo J; Auat Cheein, Fernando A; Toibero, Juan M; Mut, Vicente; Carelli, Ricardo

2011-01-01

In this work, a comparative study between an Ultra Wide-Band (UWB) localization system and a Simultaneous Localization and Mapping (SLAM) algorithm is presented. Due to its high bandwidth and short pulses length, UWB potentially allows great accuracy in range measurements based on Time of Arrival (TOA) estimation. SLAM algorithms recursively estimates the map of an environment and the pose (position and orientation) of a mobile robot within that environment. The comparative study presented here involves the performance analysis of implementing in parallel an UWB localization based system and a SLAM algorithm on a mobile robot navigating within an environment. Real time results as well as error analysis are also shown in this work.

Communication and control in an integrated manufacturing system

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Throne, Robert D.; Muthuswamy, Yogesh K.

1987-01-01

Typically, components in a manufacturing system are all centrally controlled. Due to possible communication bottlenecking, unreliability, and inflexibility caused by using a centralized controller, a new concept of system integration called an Integrated Multi-Robot System (IMRS) was developed. The IMRS can be viewed as a distributed real time system. Some of the current research issues being examined to extend the framework of the IMRS to meet its performance goals are presented. These issues include the use of communication coprocessors to enhance performance, the distribution of tasks and the methods of providing fault tolerance in the IMRS. An application example of real time collision detection, as it relates to the IMRS concept, is also presented and discussed.

Surface Tension: Mechanics, Thermodynamics, and Relaxation Times

NASA Astrophysics Data System (ADS)

Tovbin, Yu. K.

2018-06-01

A microscopic analysis is presented of the existing definitions of equilibrium surface tension, which can be divided into two types: mechanical and thermodynamic. Each type of definition can be studied from the presentation below according to thermodynamic hypotheses or molecular calculations. An analysis of the planar interface is given and its generalization for curved (spherical) interfaces is considered. The distinction between approaches describing the surface tension of metastable and equilibrium droplets is discussed. Based on nonequilibrium thermodynamics, it is shown that the introduction of metastable droplets is due to a violation of the relationship between the times of impulse and chemical potential relaxation in condensed phases. Problems of calculating the surface tension in nonequilibrium situations are created.

EARLY OR DELAYED SURGICAL TREATMENT IN COMPOUND LIMB FRACTURES DUE TO HIGH VELOCITY MISSILE INJURIES: A 5-YEAR RETROSPECTIVE STUDY FROM MEDICAL CITY IN BAGHDAD

PubMed Central

Al-Hilli, Ali Bakir; Salih, Dheyaa Saeed

2010-01-01

Background Compound limb fractures due to high-velocity missiles are complex and usually associated with multiple other injuries. These can occur in both military and civilian settings. Highvelocity missiles are presently used by terrorists worldwide. Early surgical debridement and skeletal fixation are the gold standards in managing these injuries, but data supporting these recommendations are lacking. Aim of the study Our aim was to determine the relationship between time (the time of injury to the time of surgical treatment) and the rate of deep infection in patients treated in Medical City, Baghdad, Iraq due to terrorist activity from 2004-2008. Design This is a retrospective review of a series of open limb fractures. Patients and method A total of 102 civilian patients with 114 limb fractures due to high-velocity missile injuries were selected for this study from Medical City records. Patients were followed in the outpatient department in Medical City Teaching Complex both clinically and radiologically. Results Surgical treatment was accomplished in less than six hours from time of injury in group A (55 fractures, 48.4%) and more than six hours in group B (59 fractures, 51.7%). The infection rate for group A was 30.9% and group B was 23.7%. Conclusion A very high infection rate was noted for these injuries, and there was no increase in the rate of deep infection in patients treated more than six hours after the injury. PMID:21045979

The influence of double-credit evidence-based continuing medical education on presenters and learners.

PubMed

Lawrence, Steven L; Morzinski, Jeffrey A; Radjenovich, Mary Ellen

2008-07-01

Medical specialties are adopting methods to improve continuing medical education (CME). A "double credit" option, sponsored by the American Academy of Family Physicians, is now available for presentations submitted and approved as evidence based (EB). To compare usual and double-credit CME presentations to determine differences in preparation resources and time, and to compare conference attendees' satisfaction. Those not submitting double-credit applications were asked about perceived barriers. Three pretested, written surveys were administered at a 2.5 day CME conference held annually in Southeastern Wisconsin. Subjects were 38 presenters and 172 attendees, mostly primary care physicians. Twelve presentations were approved for double-credit; these presenters used a greater percentage of on-line EB resources to prepare their talks (64% versus 23%), and preparation required an additional 4.75 hours on average. Over 90% of attendees perceived greater conference quality due to the EB emphasis. Top barriers to double-credit EB applications were time limits and perceptions that topics were inappropriate. Double-credit presenters use a greater percentage of EB resources, while their counterparts used more professional experience to prepare CME presentations. Attendees reported improved quality and value with increased EB CME. Time is a perceived and real factor in preparing double-credit applications.

[Differential diagnosis and therapy of acute abdomen in sickle cell crisis. A rare case in visceral surgery].

PubMed

Zülke, C; Graeb, C; Rüschhoff, J; Wagner, H; Jauch, K W

2000-01-01

Surgical therapy of the acute abdomen often allows only limited time for differential diagnosis to confirm the indication for surgery. Under consideration of clinical aspects and case history both common and rare causes of an acute abdomen should be investigated without undue loss of time. Differential diagnostic considerations and eventual therapy are presented in the following case of a 25-year-old Afro-american who developed multiorgan failure after an initial course of lower-back pain. In addition to the clinical setting of an acute abdomen the patient presented with acute respiratory failure and laboratory signs of severe hemolysis in combination with newly detected splenomegaly. The indication for splenectomy was made following CT-proven complete splenic infarction due to repeated acute squestration. Histologic examination of the spleen together with hemoglobin electrophoresis confirmed the clinical assumption of unusually late primary manifestation of a sickle cell crisis. In the underlying case, the hemoglobinopathy was in fact the less common form of combined sickle-cell-beta-thalassemia. A ten-day course of intensive care therapy was necessary to treat ongoing multiorgan failure due to persistent sickle cell crisis. Current diagnostic and therapeutic procedures in connection with sickle cell crisis as a rare cause of an acute abdomen with the necessity for surgical intervention are presented.

A hybrid rocket engine design for simple low cost sounding rocket use

NASA Astrophysics Data System (ADS)

Grubelich, Mark; Rowland, John; Reese, Larry

1993-06-01

Preliminary test results on a nitrous oxide/HTPB hybrid rocket engine suitable for powering a small sounding rocket to altitudes of 50-100 K/ft are presented. It is concluded that the advantage of the N2O hybrid engine over conventional solid propellant rocket motors is the ability to obtain long burn times with core burning geometries due to the low regression rate of the fuel. Long burn times make it possible to reduce terminal velocity to minimize air drag losses.

Rapid Frequency Chirps of TAE mode due to Finite Orbit Energetic Particles

NASA Astrophysics Data System (ADS)

Berk, Herb; Wang, Ge

2013-10-01

The tip model for the TAE mode in the large aspect ratio limit, conceived by Rosenbluth et al. in the frequency domain, together with an interaction term in the frequency domain based on a map model, has been extended into the time domain. We present the formal basis for the model, starting with the Lagrangian for the particle wave interaction. We shall discuss the formal nonlinear time domain problem and the procedure that needs to obtain solutions in the adiabatic limit.

Direct hyperpolarization of micro- and nanodiamonds for bioimaging applications - Considerations on particle size, functionalization and polarization loss

NASA Astrophysics Data System (ADS)

Kwiatkowski, Grzegorz; Jähnig, Fabian; Steinhauser, Jonas; Wespi, Patrick; Ernst, Matthias; Kozerke, Sebastian

2018-01-01

Due to the inherently long relaxation time of 13C spins in diamond, the nuclear polarization enhancement obtained with dynamic nuclear polarization can be preserved for a time on the order of about one hour, opening up an opportunity to use diamonds as a new class of long-lived contrast agents. The present communication explores the feasibility of using 13C spins in directly hyperpolarized diamonds for MR imaging including considerations for potential in vivo applications.

Timing of Biochemical Failure and Distant Metastasis for Low, Intermediate, and High Risk Prostate Cancer after Radiotherapy

PubMed Central

Morgan, Peter B.; Hanlon, Alexandra L.; Horwitz, Eric M.; Buyyounouski, Mark K.; Uzzo, Robert G.; Pollack, Alan

2007-01-01

Condensed Abstract The timing of biochemical failure and distant metastasis after radiotherapy for low, intermediate and high-risk prostate cancer was determined. The patterns of failure suggest that the majority of early failures were due to subclinical micrometastases present at diagnosis, whereas a late wave of metastasis at 10–12 years in every risk group was consistent with tumor spread from local persistence of disease. Background The relationship of prostate cancer risk group stratification and the timing of biochemical failure (BF) and distant metastasis (DM) is not well defined. We sought to differentiate early failures due to subclinical micrometastasis at presentation from late failures due to local persistence. Methods A total of 1833 men with clinically localized prostate cancer treated with 3D-conformal radiotherapy with or without short-term androgen deprivation were retrospectively analyzed. The interval hazard rates of DM and BF, using ASTRO and Phoenix (Nadir+2) definitions, were determined for men with low, intermediate, and high risk disease. Results Median follow-up was 67 months. Multivariate analysis showed that increasing risk group was independently associated with higher ASTRO BF (P<.0001) and Nadir+2 BF (P<.0001). The preponderance (87%) of ASTRO BF occurred ≤4 years after RT, while Nadir+2 BF was more evenly spread over years 1–12, with 43% at >4 years. The hazard of Nadir+2 BF persisted in years 8–12 in all risk groups. The interval hazard function for DM appeared to be biphasic (early and late peaks) for intermediate and high risk patients, but no distinct early wave was evident for low risk patients. Conclusions ASTRO BF underestimates late BF due to backdating. Local persistence of disease is suggested by delayed Nadir+2 BF and subsequent late DM in every risk group. The paucity of early DM among those with low risk tumors supports the hypothesis that occult micrometastases contributed to the early wave. PMID:17520705

New time-resolved micro-photoluminescence spectroscopy of natural and synthetic analogue minerals

NASA Astrophysics Data System (ADS)

Panczer, G.; Ollier, N.; Champagnon, B.; Gaft, M.

2003-04-01

Minerals as well as geomaterials often present light emissions under UV or visible excitations. This property called photoluminescence is due to low concentration impurities such as the rare earths, the transition elements and the lanthanides. The induced color is used for ore prospection but only spectroscopic analyses indicate the nature of the emitted centers. However natural samples contained numerous luminescent centers simultaneously and with regular steady-state measurements (such as in cathodoluminescence) all the emissions are often over lapping. In order to record the contributions of each separate center, it is possible to use time-resolved measurements based on the decay time of the emissions and using pulsed laser excitation. Some characteristic examples will be presented on apatites, zircons as well as gemstones. Geomaterials present as well micro scale heterogeneities (growth zoning, inclusions, devitrification, microphases...). Precise identification and optical effects of such heterogeneities have to be taken into account. To reach the microscale using photo luminescence studies, a microscope has be modified to allowed pulsed laser injection (from UV to visible), beam focus with micro scale resolution on the sample (<10 μm), as well as time resolved collection of micro fluorescence. Such equipment allows now undertaking time-resolved measurements of microphases. Applications on geomaterials will be presented.

Time evolution of pore system in lime - Pozzolana composites

NASA Astrophysics Data System (ADS)

Doleželová, Magdaléna; Čáchová, Monika; Scheinherrová, Lenka; Keppert, Martin

2017-11-01

The lime - pozzolana mortars and plasters are used in restoration works on building cultural heritage but these materials are also following the trend of energy - efficient solutions in civil engineering. Porosity and pore size distribution is one of crucial parameters influencing engineering properties of porous materials. The pore size distribution of lime based system is changing in time due to chemical processes occurring in the material. The present paper describes time evolution of pore system in lime - pozzolana composites; the obtained results are useful in prediction of performance of lime - pozzolana systems in building structures.

Visualization of the hot chocolate sound effect by spectrograms

NASA Astrophysics Data System (ADS)

Trávníček, Z.; Fedorchenko, A. I.; Pavelka, M.; Hrubý, J.

2012-12-01

We present an experimental and a theoretical analysis of the hot chocolate effect. The sound effect is evaluated using time-frequency signal processing, resulting in a quantitative visualization by spectrograms. This method allows us to capture the whole phenomenon, namely to quantify the dynamics of the rising pitch. A general form of the time dependence volume fraction of the bubbles is proposed. We show that the effect occurs due to the nonlinear dependence of the speed of sound in the gas/liquid mixture on the volume fraction of the bubbles and the nonlinear time dependence of the volume fraction of the bubbles.

Thermomechanical milling of accessory lithics in volcanic conduits

NASA Astrophysics Data System (ADS)

Campbell, Michelle E.; Russell, James K.; Porritt, Lucy A.

2013-09-01

Accessory lithic clasts recovered from pyroclastic deposits commonly result from the failure of conduit wall rocks, and represent an underutilized resource for constraining conduit processes during explosive volcanic eruptions. The morphological features of lithic clasts provide distinctive 'textural fingerprints' of processes that have reshaped them during transport in the conduit. Here, we present the first study focused on accessory lithic clast morphology and show how the shapes and surfaces of these accessory pyroclasts can inform on conduit processes. We use two main types of accessory lithic clasts from pyroclastic fallout deposits of the 2360 B.P. subplinian eruption of Mount Meager, British Columbia, as a case study: (i) rough and subangular dacite clasts, and (ii) variably rounded and smoothed monzogranite clasts. The quantitative morphological data collected on these lithics include: mass, volume, density, 2-D image analysis of convexity (C), and 3-D laser scans for sphericity (Ψ) and smoothness (S). Shaping and comminution (i.e. milling) of clasts within the conduit are ascribed to three processes: (1) disruptive fragmentation due to high-energy impacts between clasts or between clasts and conduit walls, (2) ash-blasting of clasts suspended within the volcanic flux, and (3) thermal effects. We use a simplified conduit eruption model to predict ash-blasting velocities and lithic residence times as a function of clast size and source depth, thereby constraining the lithic milling processes. The extent of shape and surface modification (i.e. rounding and honing) is directly proportional to clast residence times within the conduit prior to evacuation. We postulate that the shallow-seated dacite clasts remain subangular and rough due to short (<2 min) residence times, whereas monzogranite clasts are much more rounded and smoothed due to deeper source depths and consequently longer residence times (up to ˜1 h). Larger monzogranite clasts are smoother than smaller clasts due to longer residence times and to greater differential velocities within the ash-laden jet. Lastly, our model residence times and mass loss estimates for rounded clasts are used to estimate minimum attrition rates due to volcanic ash-blasting within the conduit (e.g., 12 cm3 s-1 for 25 cm clasts, sourced at 2500 m depth).

Harmonics suppression of vacuum chamber eddy current induced fields with application to the Superconducting Super Collider (SSC) Low Energy Booster (LEB) Magnets

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

Schlueter, R.D.; Halbach, K.

1991-12-04

This memo presents the formulation of an expression for eddy currents induced in a thin-walled conductor due to a time-dependent electromagnet field excitation. Then follows an analytical development for prediction of vacuum chamber eddy current induced field harmonics in iron-core electromagnets. A passive technique for harmonics suppression is presented with specific application to the design of the Superconducting Super Collider (SSC) Low Energy B (LEB) Magnets.

Facial diplegia: a clinical dilemma.

PubMed

Chakrabarti, Debaprasad; Roy, Mukut; Bhattacharyya, Amrit K

2013-06-01

Bilateral facial paralysis is a rare clinical entity and presents as a diagnostic challenge. Unlike its unilateral counterpart facial diplegia is seldom secondary to Bell's palsy. Occurring at a frequency of 0.3% to 2% of all facial palsies it often indicates ominous medical conditions. Guillian-Barre syndrome needs to be considered as a differential in all given cases of facial diplegia where timely treatment would be rewarding. Here a case of bilateral facial palsy due to Guillian-Barre syndrome with atypical presentation is reported.

Numerical Study of Cattaneo-Christov Heat Flux Model for Viscoelastic Flow Due to an Exponentially Stretching Surface.

PubMed

Ahmad Khan, Junaid; Mustafa, M; Hayat, T; Alsaedi, A

2015-01-01

This work deals with the flow and heat transfer in upper-convected Maxwell fluid above an exponentially stretching surface. Cattaneo-Christov heat flux model is employed for the formulation of the energy equation. This model can predict the effects of thermal relaxation time on the boundary layer. Similarity approach is utilized to normalize the governing boundary layer equations. Local similarity solutions are achieved by shooting approach together with fourth-fifth-order Runge-Kutta integration technique and Newton's method. Our computations reveal that fluid temperature has inverse relationship with the thermal relaxation time. Further the fluid velocity is a decreasing function of the fluid relaxation time. A comparison of Fourier's law and the Cattaneo-Christov's law is also presented. Present attempt even in the case of Newtonian fluid is not yet available in the literature.

Hydrogen FBG sensor using Pd/Ag film with application in propulsion system fuel tank model of aerospace vehicle

NASA Astrophysics Data System (ADS)

Saad, Said; Hassine, Lotfi; Elfahem, Wassim

2014-09-01

The high efficiency hydrogen fiber Bragg grating (FBG) sensor is presented. The sensitive film was a new alliance of palladium-silver (Pd-Ag). In addition, the titanium (Ti) layer was used as the adhesive layer. The presented sensor showed the resolution of more than 60 pm/1% H2, and a fast response time of 4 s-5 s was guaranteed in the 0.1% H2-4% H2 range. Moreover, the life time of the sensor was investigated. The obtained results showed that the sensor had an enhanced life time. Furthermore, the sensor was applied in the propulsion system fuel tank model of the aerospace vehicle. The obtained results indicated that it is a prevention system against the disaster aerospace due to hydrogen leakage.

A Full-Time Nurse for Every School: A Call to Action to Make It Happen.

PubMed

Nikpour, Jacqueline; Hassmiller, Susan

2017-09-01

In June 2016, the American Academy of Pediatrics released its new policy statement recommending a full-time registered nurse in every school building. Indeed, increasing attention is being focused on school nursing, in part due to recent legislation, including the Affordable Care Act, the Healthy Hunger-Free Kids Act, and the Every Student Succeeds Act. Advocating for nursing practice within an education setting presents unique challenges in terms of changing the common perception of school nurses, variances in funding streams for school nursing, and the ability to link health outcomes with educational outcomes. The purpose of this article is to discuss the rationale for a school nurse in every building along with presenting action steps that individual and groups of school nurses can utilize to advocate for a full-time registered nurse in every school.

Study on rotational frequency noise in a centrifugal compressor for automobile turbochargers

NASA Astrophysics Data System (ADS)

Wakaki, Daichi; Sakuka, Yuta; Yamasaki, Nobuhiko; Yamagata, Akihiro

2014-02-01

The rotational frequency noise (also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compressor for automobile turbochargers. The present paper addresses the elucidation of the generating mechanism and parameter dependency such as the kind and degree of mistuning. In order to analyze numerically the rotational frequency noise due to mistuning, the unsteady computational fluid dynamics (CFD) of the whole compressor including volute is executed, and the resultant time history of the pressure is fed into the spectral analysis.

Surface Roughness Relief

NASA Astrophysics Data System (ADS)

Marras, L.; Fontana, R.; Gambino, M. C.; Greco, M.; Materazzi, M.; Pampaloni, E.; Pezzati, L.; Poggi, P.

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a stone statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to weathering agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo's David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.

Septicaemia caused by Edwardsiella tarda and Plesiomonas shigelloides in captive penguin chicks.

PubMed

Nimmervoll, H; Wenker, C; Robert, N; Albini, S

2011-03-01

Three cases of fatal septicaemia due to Plesiomonas shigelloides and one due to Edwardsiella tarda were diagnosed in newborn penguins from the Basle Zoo, Switzerland from 2003 to 2007. The affected penguins were of two different species (king penguin, Aptenodytes patagonicus, and African penguin, Spheniscus demersus) and between 2 and 10 days old at the time of death. The causative agents, E. tarda and P. shigelloides are ubiquitous bacteria which are reported to be present in the normal intestinal flora of wild and captive aquatic animals, including penguins. Their occurrence and infectious potential is discussed.

Comparison of helicopter and ground emergency medical service: a retrospective analysis of a German rescue helicopter base.

PubMed

Mommsen, Philipp; Bradt, Nikolas; Zeckey, Christian; Andruszkow, Hagen; Petri, Max; Frink, Michael; Hildebrand, Frank; Krettek, Christian; Probst, Christian

2012-01-01

In consideration of rising cost pressure in the German health care system, the usefulness of helicopter emergency medical service (HEMS) in terms of time- and cost-effectiveness is controversially discussed. The aim of the present study was to investigate whether HEMS is associated with significantly decreased arrival and transportation times compared to ground EMS. In a retrospective study, we evaluated 1,548 primary emergency missions for time sensitive diagnoses (multiple trauma, traumatic brain and burn injury, heart-attack, stroke, and pediatric emergency) performed by a German HEMS using the medical database, NADIN, of the German Air Rescue Service. Arrival and transportation times were compared to calculated ground EMS times. HEMS showed significantly reduced arrival times at the scene in case of heart-attack, stroke and pediatric emergencies. In contrast, HEMS and ground EMS showed comparable arrival times in patients with multiple trauma, traumatic brain and burn injury due to an increased flight distance. HEMS showed a significantly decreased transportation time to the closest centre capable of specialist care in all diagnosis groups (p<0.001). The results of the present study indicate the time-effectiveness of German air ambulance services with significantly decreased transportation times.

THE NANOGRAV NINE-YEAR DATA SET: OBSERVATIONS, ARRIVAL TIME MEASUREMENTS, AND ANALYSIS OF 37 MILLISECOND PULSARS

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

Arzoumanian, Zaven; Brazier, Adam; Chatterjee, Shami

2015-11-01

We present high-precision timing observations spanning up to nine years for 37 millisecond pulsars monitored with the Green Bank and Arecibo radio telescopes as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project. We describe the observational and instrumental setups used to collect the data, and methodology applied for calculating pulse times of arrival; these include novel methods for measuring instrumental offsets and characterizing low signal-to-noise ratio timing results. The time of arrival data are fit to a physical timing model for each source, including terms that characterize time-variable dispersion measure and frequency-dependent pulse shape evolution. Inmore » conjunction with the timing model fit, we have performed a Bayesian analysis of a parameterized timing noise model for each source, and detect evidence for excess low-frequency, or “red,” timing noise in 10 of the pulsars. For 5 of these cases this is likely due to interstellar medium propagation effects rather than intrisic spin variations. Subsequent papers in this series will present further analysis of this data set aimed at detecting or limiting the presence of nanohertz-frequency gravitational wave signals.« less

Organic amaranth starch: A study of its technological properties after heat-moisture treatment.

PubMed

Bet, Camila Delinski; de Oliveira, Cristina Soltovski; Colman, Tiago André Denck; Marinho, Marina Tolentino; Lacerda, Luiz Gustavo; Ramos, Augusto Pumacahua; Schnitzler, Egon

2018-10-30

Organic amaranth starch (Amaranthus caudatus) was studied after heat-moisture treatment (HMT) using different moisture contents and different times. The starch extracted by the aqueous method presented low lipid and protein content. After HMT, an increase in the thermal stability was identified. The onset and peak temperatures were higher with an increase in moisture content and the times used in the modification. The gelatinisation enthalpy varied due to the heterogeneity of the crystals formed after the structural reorganisation caused by HMT. The relative crystallinity was lower for the physically modified starches. An increase in the pasting temperature was accompanied by a decrease in the viscosity, setback and breakdown, which were proportional to the moisture and time used. The morphology of the HMT-modified samples was not altered; however, agglomerations were noted. Low levels of dispersion homogeneity and suspension stability were observed for the modified samples due to the strong presence of agglomerates. Published by Elsevier Ltd.

The Broad Iron K-alpha line of Cygnus X-1 as Seen by XMM-Newton in the EPIC-pn Modified Timing Mode

NASA Technical Reports Server (NTRS)

Duro, Refiz; Dauser, Thomas; Wilms, Jorn; Pottschmidt, Katja; Nowak, Michael A.; Fritz, Sonja; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Reynolds, Christopher S.; Staubert, Rudiger

2011-01-01

We present the analysis of the broadened, flourescent iron K(alpha) line in simultaneous XMM-Newton and RXTE data from the black hole Cygnus X-I. The XMM-Newton data were taken in a modified version of the Timing Mode of the EPIC-pn camera. In this mode the lower energy threshold of the instrument is increased to 2.8 keV to avoid telemetry drop outs due to the brightness of the source, while at the same time preserving the signal to noise ratio in the Fe K(alpha) band. We find that the best-fit spectrum consists of the sum of an exponentially cut-off power-law and relativistically smeared, ionized reflection. The shape of the broadened Fe K(alpha) feature is due to strong Compton broadening combined with relativistic broadening. Assuming a standard, thin accretion disk, the black hole is close to maximally rotating. Key words. X-rays: binaries - black hole physics - gravitation

Pesticide uptake in potatoes: model and field experiments.

PubMed

Juraske, Ronnie; Vivas, Carmen S Mosquera; Velásquez, Alexander Erazo; Santos, Glenda García; Moreno, Mónica B Berdugo; Gomez, Jaime Diaz; Binder, Claudia R; Hellweg, Stefanie; Dallos, Jairo A Guerrero

2011-01-15

A dynamic model for uptake of pesticides in potatoes is presented and evaluated with measurements performed within a field trial in the region of Boyacá, Colombia. The model takes into account the time between pesticide applications and harvest, the time between harvest and consumption, the amount of spray deposition on soil surface, mobility and degradation of pesticide in soil, diffusive uptake and persistence due to crop growth and metabolism in plant material, and loss due to food processing. Food processing steps included were cleaning, washing, storing, and cooking. Pesticide concentrations were measured periodically in soil and potato samples from the beginning of tuber formation until harvest. The model was able to predict the magnitude and temporal profile of the experimentally derived pesticide concentrations well, with all measurements falling within the 90% confidence interval. The fraction of chlorpyrifos applied on the field during plant cultivation that eventually is ingested by the consumer is on average 10(-4)-10(-7), depending on the time between pesticide application and ingestion and the processing step considered.

Variation in organic matter and water color in Lake Mälaren during the past 70 years.

PubMed

Johansson, L; Temnerud, J; Abrahamsson, J; Berggren Kleja, D

2010-03-01

Interest in long time series of organic matter data has recently increased due to concerns about the effects of global climate change on aquatic ecosystems. This study presents and evaluates unique time series of chemical oxygen demand (COD) and water color from Lake Malaren, Sweden, stretching almost seven decades (1935-2004). A negative linear trend was found in COD, but not in water color. The decrease was mainly due to installation of sewage works around 1970. Time series of COD and water color had cyclic pattern. It was strongest for COD, with 23 years periodicity. Similar periodicity observed in air temperature and precipitation in Sweden has been attributed to the North Atlantic Oscillation index and solar system orbit, suggesting that COD in Lake Mälaren is partly derived from algae. Discharge influenced water color more than COD, possibly because water color consists of colored substances brought into the lake from surrounding soils.

Tidal reorientation and the fracturing of Jupiter's moon Europa

USGS Publications Warehouse

McEwen, A.S.

1986-01-01

The most striking characteristic of Europa is the network of long linear albedo markings over the surface, suggestive of global-scale tectonic processes. Various explanations for the fractures have been proposed: Freezing and expansion of an early liquid water ocean1, planetary expansion due to dehydration of hydrated silicates2, localization by weak points in the crust generated by impacts3, and a combination of stresses due to planetary volume change and tidal distortions from orbital recession and orbital eccentricity4,5. Calculations by Yoder6 and Greenberg and Weidenschilling7 have shown that Europa may rotate slightly more rapidly than the synchronous rate, with a rotation period (reorientation through 360??) ranging from 20 to >103 yr if a liquid mantle is present, or up to 1010 yr if the satellite is essentially solid7. Helfen-stein and Parmentier8 modelled the stresses due to nonsynchronous rotation, and concluded that this could explain the long fractures in part of the anti-jovian hemisphere. In this note, I present a global map of lineaments with long arc lengths (>20?? or 550 km), and compare the lineament orientations to the tensile stress trajectories due to tidal distortions (changes in the lengths of three principal semiaxes) and to nonsynchronous rotation (longitudinal reorientation of two of the principal semiaxes). An excellent orthogonal fit to the lineaments is achieved by the stresses due to nonsynchronous rotation with the axis radial to Jupiter located 25?? east of its present position. This fit suggests that nonsynchronous rotation occurred at some time in Europa's history. ?? 1986 Nature Publishing Group.

Review of Article, A Case for Submicrosecond Rise-Time Lightning Current Pulses for Use in Aircraft Induced-Coupling Studies, by D. W. Clifford, E. P. Krider and M. A. Uman

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

Cabayan, H.S.; Zicker, J.D.

The amplitudes of currents due to lightning are considerably larger than NEMP induced currents both in the time and frequency domains. The more important quantity for aperture illumination is the rate of rise of the current. The analysis performed for this in this memorandum is unsatisfactory since the artificial double exponential model was used. Still, the lightning rate of rise is only twice as high as that due to NEMP even when the absolute worst (or presently known) lightning pulse is used. A much better way to do this comparison is to use an actual LEMP data and NEMP frommore » an actual weapon. Furthermore, because of lack of data, no electric field analysis was undertaken.« less

A centralized audio presentation manager

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

Papp, A.L. III; Blattner, M.M.

1994-05-16

The centralized audio presentation manager addresses the problems which occur when multiple programs running simultaneously attempt to use the audio output of a computer system. Time dependence of sound means that certain auditory messages must be scheduled simultaneously, which can lead to perceptual problems due to psychoacoustic phenomena. Furthermore, the combination of speech and nonspeech audio is examined; each presents its own problems of perceptibility in an acoustic environment composed of multiple auditory streams. The centralized audio presentation manager receives abstract parameterized message requests from the currently running programs, and attempts to create and present a sonic representation in themore » most perceptible manner through the use of a theoretically and empirically designed rule set.« less

Hands-On in the Non-Laboratory Classroom Reconstructing Plant Phylogenies Using Morphological Characters

ERIC Educational Resources Information Center

Flory, S. Luke; Ingram, Ella L.; Heidinger, Britt J.; Tintjer, Tammy

2005-01-01

Laboratory components of introductory biology college-level courses are becoming increasingly rare. Due to the absence of laboratory funding and time, instructors at all levels are faced with the problem of implementing inquiry-based projects. In this article, the authors present an activity that they developed for the 50-minute discussion period…

Voice Onset Time in Consonant Cluster Errors: Can Phonetic Accommodation Differentiate Cognitive from Motor Errors?

ERIC Educational Resources Information Center

Pouplier, Marianne; Marin, Stefania; Waltl, Susanne

2014-01-01

Purpose: Phonetic accommodation in speech errors has traditionally been used to identify the processing level at which an error has occurred. Recent studies have challenged the view that noncanonical productions may solely be due to phonetic, not phonological, processing irregularities, as previously assumed. The authors of the present study…

VR-Based Gamification of Communication Training and Oral Examination in a Second Language

ERIC Educational Resources Information Center

Reitz, Liesa; Sohny, Aline; Lochmann, Gerrit

2016-01-01

The authors present a novel way of oral language training by embedding the English as a foreign language (EFL) learning process into a generic 3D Cooperative Virtual Reality (VR) Game. Due to lack of time, resources and innovation, the language classroom is limited in its possibilities of promoting authentic communication. Therefore, the…

An Inventory for Measuring Student Teachers' Knowledge of Chemical Representations: Design, Validation, and Psychometric Analysis

ERIC Educational Resources Information Center

Taskin, V.; Bernholt, S.; Parchmann, I.

2015-01-01

Chemical representations play an important role in helping learners to understand chemical contents. Thus, dealing with chemical representations is a necessity for learning chemistry, but at the same time, it presents a great challenge to learners. Due to this great challenge, it is not surprising that numerous national and international studies…

Darkened skin, vomiting, and salt cravings in a teenager · Dx?

PubMed

Lee, Tsan; Kapadia, Chirag

2016-06-01

Acute adrenal insufficiency crisis usually occurs after a prolonged period of nonspecific complaints due to a loss of both glucocorticoids and mineralocorticoids; by the time overt symptoms occur, 90% of the adrenal gland may be destroyed. Patients (such as ours) may present with symptoms such as abdominal pain, weakness, vomiting, fever, and decreased responsiveness.

Mapping in an apple (Malus x domestica) F1 segregating population based on physical clustering of differentially expressed genes

USDA-ARS?s Scientific Manuscript database

Background: Apple tree breeding is slow and difficult due to long generation times, self incompatibility, and complex genetics. The identification of molecular markers linked to traits of interest is a way to expedite the breeding process. In the present study, we aimed to identify genes whose stead...

Relationship between Effective Application of Machine Learning and Malware Detection: A Quantitative Study

ERIC Educational Resources Information Center

Enfinger, Kerry Wayne

2016-01-01

The number of malicious files present in the public domain continues to rise at a substantial rate. Current anti-malware software utilizes a signature-based method to detect the presence of malicious software. Generating these pattern signatures is time consuming due to malicious code complexity and the need for expert analysis, however, by making…

Hereditarian Ideas and Eugenic Ideals at the National Deaf-Mute College

ERIC Educational Resources Information Center

Ennis, William Thomas, III

2015-01-01

For the past two centuries deaf people in the United States have faced more or less intense skepticism about their marriages to each other, largely due to fears of inherited deafness. These fears, while always present, have waxed and waned over time, becoming most prominent during the eugenics era of the late nineteenth and early twentieth…

Thrombotic thrombocytopenic purpura in a patient with sickle cell crisis.

PubMed

Bolaños-Meade, J; Keung, Y K; López-Arvizu, C; Florendo, R; Cobos, E

1999-12-01

The combination of sickle cell disease crisis and thrombotic thrombocytopenic purpura has been described only a few times. Here we present the case of a patient with a hemolytic crisis due to sickle cell disease complicated by thrombotic thrombocytopenic purpura. We also review the cases previously reported and compare and contrast them, highlighting diagnostic challenges.

A model for estimating understory vegetation response to fertilization and precipitation in loblolly pine plantations

Treesearch

Curtis L. VanderSchaaf; Ryan W. McKnight; Thomas R. Fox; H. Lee Allen

2010-01-01

A model form is presented, where the model contains regressors selected for inclusion based on biological rationale, to predict how fertilization, precipitation amounts, and overstory stand density affect understory vegetation biomass. Due to time, economic, and logistic constraints, datasets of large sample sizes generally do not exist for understory vegetation. Thus...

Glucose-6-Phosphate-Dehydrogenase Is Also Increased in Erythrocytes from Adolescents with Down Syndrome

ERIC Educational Resources Information Center

Ordonez, Francisco J.; Rosety-Plaza, Manuel; Rosety-Rodriguez, Manuel

2006-01-01

For some time it has been claimed that trisomic cells are more sensitive to oxidative stress since there is an imbalance in hydrogen peroxide metabolism due to an increase in superoxide dismutase (SOD) catalytic activity. We designed the present study to assess activity levels of antioxidant enzymes [superoxide dismutase (SOD), glutathione…

Strategies of Collaborative Work in the Classroom through the Design of Video Games

ERIC Educational Resources Information Center

Muñoz González, Juan Manuel; Rubio García, Sebastián; Cruz Pichardo, Ivanovna M.

2015-01-01

At the present time, the use of video games goes beyond mere amusement or entertainment due to its potential for developing capacities, dexterity and skills. Thus, video games have extended to environments like that of education, serving as didactic resources within dynamics that respond to the interests and necessities of the 21st century…

Behavioral Criteria in Research and the Study of Racism: Performing the Jackal Function (Final Report).

ERIC Educational Resources Information Center

Hilliard, Asa G.; And Others

This report describes the methodology and results of a study of racist attitudes and behaviors. The introduction provides the background and states difficulties due to funding and time constraints. Research and data collection procedures are delineated in the second section. In section 3, results are presented in tabular form, and intercoder…

Slow Mapping: Color Word Learning as a Gradual Inductive Process

ERIC Educational Resources Information Center

Wagner, Katie; Dobkins, Karen; Barner, David

2013-01-01

Most current accounts of color word acquisition propose that the delay between children's first production of color words and adult-like understanding is due to problems abstracting color as a domain of meaning. Here we present evidence against this hypothesis, and show that, from the time children produce color words in a labeling task they use…

Amelioration of pregnancy-associated osteoporosis after treatment with vitamin K₂: a report of four patients.

PubMed

Tsuchie, Hiroyuki; Miyakoshi, Naohisa; Hongo, Michio; Kasukawa, Yuji; Ishikawa, Yoshinori; Shimada, Yoichi

2012-08-01

Abstract We demonstrate for the first time therapeutic effects of vitamin K₂ (menatetrenone) on pregnancy-associated osteoporosis with multiple vertebral fractures in four cases. Due to its safety, vitamin K₂ presents itself as a treatment option for women with pregnancy-associated osteoporosis. Desirably, future controlled studies should verify these findings.

Bone metastases as initial presentation of hepatocellular carcinoma.

PubMed

Monteserin, Luzdivina; Mesa, Alicia; Fernandez-Garcia, Maria Soledad; Gadanon-Garcia, Arantza; Rodriguez, Manuel; Varela, María

2017-10-18

Extra-hepatic spread is present in 5% to 15% of patients with hepatocellular carcinoma (HCC) at the time of diagnosis. The most frequent sites are lung and regional lymph nodes. Here, we report 3 cases of unsuspected HCC with symptoms due to bone lesions as initial presentation. Morphological characteristics and immunohistochemistry from the examined bone were the key data for diagnosis. None of the patients had an already known chronic liver disease. Differential diagnoses with HCC upon ectopic liver disease or hepatoid adenocarcinoma were shown. Therapy with the orally active multikinase inhibitor sorafenib plus symptomatic treatment was indicated.

Online Bagging and Boosting

NASA Technical Reports Server (NTRS)

Oza, Nikunji C.

2005-01-01

Bagging and boosting are two of the most well-known ensemble learning methods due to their theoretical performance guarantees and strong experimental results. However, these algorithms have been used mainly in batch mode, i.e., they require the entire training set to be available at once and, in some cases, require random access to the data. In this paper, we present online versions of bagging and boosting that require only one pass through the training data. We build on previously presented work by presenting some theoretical results. We also compare the online and batch algorithms experimentally in terms of accuracy and running time.

A new facility for non-destructive assay using a 252Cf source.

PubMed

Stevanato, L; Caldogno, M; Dima, R; Fabris, D; Hao, Xin; Lunardon, M; Moretto, S; Nebbia, G; Pesente, S; Pino, F; Sajo-Bohus, L; Viesti, G

2013-03-01

A new laboratory facility for non-destructive analysis (NDA) using a time-tagged (252)Cf source is presented. The system is designed to analyze samples having maximum size of about 20 × 25 cm(2), the material recognition being obtained by measuring simultaneously total and energy dependent transmission of neutrons and gamma rays. The equipment technical characteristics and performances of the NDA system are presented, exploring also limits due to the sample thickness. Some recent applications in the field of cultural heritage are presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

Segmentation and analysis of mouse pituitary cells with graphic user interface (GUI)

NASA Astrophysics Data System (ADS)

González, Erika; Medina, Lucía.; Hautefeuille, Mathieu; Fiordelisio, Tatiana

2018-02-01

In this work we present a method to perform pituitary cell segmentation in image stacks acquired by fluorescence microscopy from pituitary slice preparations. Although there exist many procedures developed to achieve cell segmentation tasks, they are generally based on the edge detection and require high resolution images. However in the biological preparations that we worked on, the cells are not well defined as experts identify their intracellular calcium activity due to fluorescence intensity changes in different regions over time. This intensity changes were associated with time series over regions, and because they present a particular behavior they were used into a classification procedure in order to perform cell segmentation. Two logistic regression classifiers were implemented for the time series classification task using as features the area under the curve and skewness in the first classifier and skewness and kurtosis in the second classifier. Once we have found both decision boundaries in two different feature spaces by training using 120 time series, the decision boundaries were tested over 12 image stacks through a python graphical user interface (GUI), generating binary images where white pixels correspond to cells and the black ones to background. Results show that area-skewness classifier reduces the time an expert dedicates in locating cells by up to 75% in some stacks versus a 92% for the kurtosis-skewness classifier, this evaluated on the number of regions the method found. Due to the promising results, we expect that this method will be improved adding more relevant features to the classifier.

High-rate synthetic aperture communications in shallow water.

PubMed

Song, H C; Hodgkiss, W S; Kuperman, W A; Akal, T; Stevenson, M

2009-12-01

Time reversal communication exploits spatial diversity to achieve spatial and temporal focusing in complex ocean environments. Spatial diversity can be provided easily by a vertical array in a waveguide. Alternatively, spatial diversity can be obtained from a virtual horizontal array generated by two elements, a transmitter and a receiver, due to relative motion between them, referred to as a synthetic aperture. This paper presents coherent synthetic aperture communication results from at-sea experiments conducted in two different frequency bands: (1) 2-4 kHz and (2) 8-20 kHz. Case (1) employs binary-phase shift-keying modulation, while case (2) involves up to eight-phase shift keying modulation with a data rate of 30 kbits/s divided by the number of transmissions (diversity) to be accumulated. The receiver utilizes time reversal diversity combining followed by a single channel equalizer, with frequent channel updates to accommodate the time-varying channel due to coupling of space and time in the presence of motion. Two to five consecutive transmissions from a source moving at 4 kts over 3-6 km range in shallow water are combined successfully after Doppler compensation, confirming the feasibility of coherent synthetic aperture communications using time reversal.

A robust and high-performance queue management controller for large round trip time networks

NASA Astrophysics Data System (ADS)

Khoshnevisan, Ladan; Salmasi, Farzad R.

2016-05-01

Congestion management for transmission control protocol is of utmost importance to prevent packet loss within a network. This necessitates strategies for active queue management. The most applied active queue management strategies have their inherent disadvantages which lead to suboptimal performance and even instability in the case of large round trip time and/or external disturbance. This paper presents an internal model control robust queue management scheme with two degrees of freedom in order to restrict the undesired effects of large and small round trip time and parameter variations in the queue management. Conventional approaches such as proportional integral and random early detection procedures lead to unstable behaviour due to large delay. Moreover, internal model control-Smith scheme suffers from large oscillations due to the large round trip time. On the other hand, other schemes such as internal model control-proportional integral and derivative show excessive sluggish performance for small round trip time values. To overcome these shortcomings, we introduce a system entailing two individual controllers for queue management and disturbance rejection, simultaneously. Simulation results based on Matlab/Simulink and also Network Simulator 2 (NS2) demonstrate the effectiveness of the procedure and verify the analytical approach.

Experimental Evaluation of a Deformable Registration Algorithm for Motion Correction in PET-CT Guided Biopsy.

PubMed

Khare, Rahul; Sala, Guillaume; Kinahan, Paul; Esposito, Giuseppe; Banovac, Filip; Cleary, Kevin; Enquobahrie, Andinet

2013-01-01

Positron emission tomography computed tomography (PET-CT) images are increasingly being used for guidance during percutaneous biopsy. However, due to the physics of image acquisition, PET-CT images are susceptible to problems due to respiratory and cardiac motion, leading to inaccurate tumor localization, shape distortion, and attenuation correction. To address these problems, we present a method for motion correction that relies on respiratory gated CT images aligned using a deformable registration algorithm. In this work, we use two deformable registration algorithms and two optimization approaches for registering the CT images obtained over the respiratory cycle. The two algorithms are the BSpline and the symmetric forces Demons registration. In the first optmization approach, CT images at each time point are registered to a single reference time point. In the second approach, deformation maps are obtained to align each CT time point with its adjacent time point. These deformations are then composed to find the deformation with respect to a reference time point. We evaluate these two algorithms and optimization approaches using respiratory gated CT images obtained from 7 patients. Our results show that overall the BSpline registration algorithm with the reference optimization approach gives the best results.

Esophageal button battery ingestions: decreasing time to operative intervention by level I trauma activation.

PubMed

Russell, Robert T; Griffin, Russell L; Weinstein, Elizabeth; Billmire, Deborah F

2014-09-01

The incidence of button battery ingestions is increasing and injury due to esophageal impaction begins within minutes of exposure. We changed our management algorithm for suspected button battery ingestions with intent to reduce time to evaluation and operative removal. A retrospective study was performed to identify and evaluate time to treatment and outcome for all esophageal button battery ingestions presenting to a major children's hospital emergency room from February 1, 2010 through February 1, 2012. During the first year, standard emergency room triage (ST) was used. During the second year, the triage protocol was changed and Trauma I triage (TT) was used. 24 children had suspected button battery ingestions with 11 having esophageal impaction. One esophageal impaction was due to 2 stacked coins. Time from arrival in emergency room to battery removal was 183minutes in ST group (n=4) and 33minutes in TT group (n=7) (p=0.04). One patient in ST developed a tracheoesophageal fistula. There were no complications in the TT group. The use of Trauma 1 activations for suspected button battery ingestions has led to more expedient evaluation and shortened time to removal of impacted esophageal batteries. Copyright © 2014 Elsevier Inc. All rights reserved.

Trans-tibial amputee gait: time-distance parameters and EMG activity.

PubMed

Isakov, E; Keren, O; Benjuya, N

2000-12-01

Gait analysis of trans-tibial (TT) amputees discloses asymmetries in gait parameters between the amputated and sound legs. The present study aimed at outlining differences between both legs with regard to kinematic parameters and activity of the muscles controlling the knees. The gait of 14 traumatic TT amputees, walking at a mean speed of 74.96 m/min, was analysed by means of an electronic walkway, video camera, and portable electromyography system. Results showed differences in kinematic parameters. Step length, step time and swing time were significantly longer, while stance time and single support time were significantly shorter on the amputated side. A significant difference was also found between knee angle in both legs at heel strike. The biceps femoris/vastus medialis ratio in the amputated leg, during the first half of stance phase, was significantly higher when compared to the same muscle ratio in the sound leg. This difference was due to the higher activity of the biceps femoris, almost four times higher than the vastus medialis in the amputated leg. The observed differences in time-distance parameters are due to stiffness of the prosthesis ankle (the SACH foot) that impedes the normal forward advance of the amputated leg during the first half of stance. The higher knee flexion at heel strike is due to the necessary socket alignment. Unlike in the sound leg, the biceps femoris in the amputated leg reaches maximal activity during the first half of stance, cocontracting with the vastus medialis, to support body weight on the amputated leg. The obtained data can serve as a future reference for evaluating the influence of new prosthetic components on the quality of TT amputee's gait.

Computing moment to moment BOLD activation for real-time neurofeedback

PubMed Central

Hinds, Oliver; Ghosh, Satrajit; Thompson, Todd W.; Yoo, Julie J.; Whitfield-Gabrieli, Susan; Triantafyllou, Christina; Gabrieli, John D.E.

2013-01-01

Estimating moment to moment changes in blood oxygenation level dependent (BOLD) activation levels from functional magnetic resonance imaging (fMRI) data has applications for learned regulation of regional activation, brain state monitoring, and brain-machine interfaces. In each of these contexts, accurate estimation of the BOLD signal in as little time as possible is desired. This is a challenging problem due to the low signal-to-noise ratio of fMRI data. Previous methods for real-time fMRI analysis have either sacrificed the ability to compute moment to moment activation changes by averaging several acquisitions into a single activation estimate or have sacrificed accuracy by failing to account for prominent sources of noise in the fMRI signal. Here we present a new method for computing the amount of activation present in a single fMRI acquisition that separates moment to moment changes in the fMRI signal intensity attributable to neural sources from those due to noise, resulting in a feedback signal more reflective of neural activation. This method computes an incremental general linear model fit to the fMRI timeseries, which is used to calculate the expected signal intensity at each new acquisition. The difference between the measured intensity and the expected intensity is scaled by the variance of the estimator in order to transform this residual difference into a statistic. Both synthetic and real data were used to validate this method and compare it to the only other published real-time fMRI method. PMID:20682350

Factors influencing the latency of simple reaction time

PubMed Central

Woods, David L.; Wyma, John M.; Yund, E. William; Herron, Timothy J.; Reed, Bruce

2015-01-01

Simple reaction time (SRT), the minimal time needed to respond to a stimulus, is a basic measure of processing speed. SRTs were first measured by Francis Galton in the 19th century, who reported visual SRT latencies below 190 ms in young subjects. However, recent large-scale studies have reported substantially increased SRT latencies that differ markedly in different laboratories, in part due to timing delays introduced by the computer hardware and software used for SRT measurement. We developed a calibrated and temporally precise SRT test to analyze the factors that influence SRT latencies in a paradigm where visual stimuli were presented to the left or right hemifield at varying stimulus onset asynchronies (SOAs). Experiment 1 examined a community sample of 1469 subjects ranging in age from 18 to 65. Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education. As in previous studies, SRTs were prolonged at shorter SOAs and were slightly faster for stimuli presented in the visual field contralateral to the responding hand. Stimulus detection time (SDT) was estimated by subtracting movement initiation time, measured in a speeded finger tapping test, from SRTs. SDT latencies averaged 131 ms and were unaffected by age. Experiment 2 tested 189 subjects ranging in age from 18 to 82 years in a different laboratory using a larger range of SOAs. Both SRTs and SDTs were slightly prolonged (by 7 ms). SRT latencies increased with age while SDT latencies remained stable. Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output. PMID:25859198

Recreational impacts on Colorado River beaches in Glen Canyon, Arizona

NASA Astrophysics Data System (ADS)

Carothers, Steven W.; Johnson, Robert A.; Dolan, Robert

1984-07-01

Recreational impact was measured on eight beaches in Glen Canyon National Recreation Area and 15 beaches in Grand Canyon National Park using permanently located transects and plots. Recreational impact indices included densities of human trash and charcoal and a measure of sand discoloration due to charcoal. Significant increases in the indices occurred on several Glen Canyon beaches over a seven-month period. Sand discoloration became significantly higher over all Glen Canyon beaches during the same time period. All indices were significantly higher in Glen Canyon than on similar Grand Canyon beaches. These differences are probably due to differences in: (a) level of impacts tolerated by the respective management regimes and, (b) in the number of user days among the two National Park Service administrative units. Management alternatives are presented for reversing the present trends of recreational impact on Glen Canyon beaches.

Heating, moisture, and water budgets of tropical and midlatitude squall lines - Comparisons and sensitivity to longwave radiation

NASA Technical Reports Server (NTRS)

Tao, W.-K.; Simpson, J.; Sui, C.-H.; Ferrier, B.; Lang, S.; Scala, J.; Chou, M.-D.; Pickering, K.

1993-01-01

A 2D time-dependent and nonhydrostatic numerical cloud model is presently used to estimate the heating, moisture, and water budgets in the convective and stratiform regions for both a tropical and a midlatitude squall line. The model encompasses a parameterized, three-class ice phase microphysical scheme and longwave radiative transfer process. It is noted that the convective region plays an important role in the generation of stratiform rainfall for both cases. While a midlevel minimum in the moisture profile for the tropical case is due to vertical eddy transport in the convective region, the contribution to the heating budget by the cloud-scale fluxes is minor; by contrast, the vertical eddy heat-flux is relatively important for the midlatitude case due to the stronger vertical velocities present in the convective cells.

Orbital Disturbance Analysis due to the Lunar Gravitational Potential and Deviation Minimization through the Trajectory Control in Closed Loop

NASA Astrophysics Data System (ADS)

Gonçalves, L. D.; Rocco, E. M.; de Moraes, R. V.

2013-10-01

A study evaluating the influence due to the lunar gravitational potential, modeled by spherical harmonics, on the gravity acceleration is accomplished according to the model presented in Konopliv (2001). This model provides the components x, y and z for the gravity acceleration at each moment of time along the artificial satellite orbit and it enables to consider the spherical harmonic degree and order up to100. Through a comparison between the gravity acceleration from a central field and the gravity acceleration provided by Konopliv's model, it is obtained the disturbing velocity increment applied to the vehicle. Then, through the inverse problem, the Keplerian elements of perturbed orbit of the satellite are calculated allowing the orbital motion analysis. Transfer maneuvers and orbital correction of lunar satellites are simulated considering the disturbance due to non-uniform gravitational potential of the Moon, utilizing continuous thrust and trajectory control in closed loop. The simulations are performed using the Spacecraft Trajectory Simulator-STRS, Rocco (2008), which evaluate the behavior of the orbital elements, fuel consumption and thrust applied to the satellite over the time.

Warfarin hypersensitivity due to gluten-sensitive enteropathy: a case study.

PubMed

Kwolek, Sara; Deming, Paula

2012-01-01

A 53 year old female who was maintained on long-term warfarin therapy due to history of pulmonary embolism, repeatedly presents with an abnormally prolonged Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). After many asymptomatic episodes were corrected with Vitamin K therapy to temporarily reverse the effects of the warfarin, the cause of the apparent coagulopathy was further investigated. Factor Activity Assays of the common pathway factors II, IX, and X all revealed critically low values; below the threshold even a loading dose of warfarin is typically capable of eliciting. The patient tested strongly positive for Tissue Transglutaminase IgA, which is highly suggestive of a gluten-sensitive enteropathy. One effect of this condition is malabsorption due to flattened intestinal villi. The patient was determined to have an acquired vitamin K deficiency secondary to gluten-sensitive enteropathy. Her condition was exacerbated by the long-term warfarin therapy, resulting in the prolonged PT and PTT. The patient was treated with vitamin K therapy, which reversed the deficiency and corrected her abnormal coagulation results.

Controlling state explosion during automatic verification of delay-insensitive and delay-constrained VLSI systems using the POM verifier

NASA Technical Reports Server (NTRS)

Probst, D.; Jensen, L.

1991-01-01

Delay-insensitive VLSI systems have a certain appeal on the ground due to difficulties with clocks; they are even more attractive in space. We answer the question, is it possible to control state explosion arising from various sources during automatic verification (model checking) of delay-insensitive systems? State explosion due to concurrency is handled by introducing a partial-order representation for systems, and defining system correctness as a simple relation between two partial orders on the same set of system events (a graph problem). State explosion due to nondeterminism (chiefly arbitration) is handled when the system to be verified has a clean, finite recurrence structure. Backwards branching is a further optimization. The heart of this approach is the ability, during model checking, to discover a compact finite presentation of the verified system without prior composition of system components. The fully-implemented POM verification system has polynomial space and time performance on traditional asynchronous-circuit benchmarks that are exponential in space and time for other verification systems. We also sketch the generalization of this approach to handle delay-constrained VLSI systems.

Numerical assessment of wind turbine blade damage due to contact/impact with tower during installation

NASA Astrophysics Data System (ADS)

Shankar Verma, Amrit; Petter Vedvik, Nils; Gao, Zhen

2017-12-01

The use of floating crane vessel for installation of offshore wind turbine blades presents a great challenge in terms of its random motions and is likely to increase the probability of the blade hitting the preassembled tower during lifting operation. To evaluate the consequences of such scenarios and to determine the allowable motions or sea states for such operations, it is very important to understand the damage development in the blade due to impact. The present paper employs the application of high fidelity finite element method to investigate the damage behavior in the blade when the leading edge of the blade hits the tower. A nonlinear time domain structural analysis using ABAQUS was conducted on the DTU 10 MW reference blade model which is based on shell elements. Damage assessment along with the nature of evolution of various energies is examined and presented for two different impact velocities with modified layup stacking sequence at the contact region.

Recent advances in active noise and vibration control at NASA Langley Research Center

NASA Astrophysics Data System (ADS)

Gibbs, Gary P.; Cabell, Randolph H.; Palumbo, Daniel L.; Silcox, Richard J.; Turner, Travis L.

2002-11-01

Over the past 15 years NASA has investigated the use of active control technology for aircraft interior noise. More recently this work has been supported through the Advanced Subsonic Technology Noise Reduction Program (1994-2001), High Speed Research Program (1994-1999), and through the Quiet Aircraft Technology Program (2000-present). The interior environment is recognized as an important element in flight safety, crew communications and fatigue, as well as passenger comfort. This presentation will overview research in active noise and vibration control relating to interior noise being investigated by NASA. The research to be presented includes: active control of aircraft fuselage sidewall transmission due to turbulent boundary layer or jet noise excitation, active control of interior tones due to propeller excitation of aircraft structures, and adaptive stiffening of structures for noise, vibration, and fatigue control. Work on actuator technology ranging from piezoelectrics, shape memory actuators, and fluidic actuators will be described including applications. Control system technology will be included that is experimentally based, real-time, and adaptive.

Study of the long time-scale variability of cosmic rays with the ARGO-YBJ experiment

NASA Astrophysics Data System (ADS)

Cappa, Alba; James, Irina; Salvini, Paola

The long term modulation of the cosmic ray intensity includes both Sun and celestial anisotropies. The solar activity is due to high energy flares producing a decrease (known as Forbush Decrease, FD) in the cosmic ray intensity, with a time scale of the order of a few days, often accompained by a Ground Level Enhancement, due to direct Sun emission during the solar flare. The celestial anisotropies are due to the Earth motion in the cosmic rays reference system (solar anisotropy: Compton-Getting effect) and to the solar system location inside the Galaxy (sidereal anisotropies). These anisotropies are studied in ground-base experiments by means of EAS arrays, and the high energy solar emission is mainly studied from ground by neutron monitors. In the ARGO-YBJ experiment these phenomena are investigated by means of the "scaler mode" technique: the detector counting rates of four low multiplicity channels from singles to four-fold coincidences are recorded in a fixed time window of 0.5 s. The signal corresponds to a significant enhancement of the observed counting rate, after correcting the data for enviromental and instrumental parameters. In this paper we present the sensitivity of the ARGO-YBJ detector and the first results for both solar physics and cosmic ray anisotropy studies.

Real-Time X-Ray Microscopy of Al-Cu Eutectic Solidification

NASA Technical Reports Server (NTRS)

Kaukler, William F.; Curreri, Peter A.; Sen, Subhayu

1998-01-01

Recent improvements in the resolution of the X-ray Transmission Microscope (XTM) for Solidification Studies provide microstructure feature detectability down to 5 micrometers during solidification. This presentation will show the recent results from observations made in real-time of the solid-liquid interfacial morphologies of the Al-CuAI2 eutectic alloy. Lamellar dimensions and spacings, transitions of morphology caused by growth rate changes, and eutectic grain structures are open to measurements. A unique vantage point viewing the face of the interface isotherm is possible for the first time with the XTM due to its infinite depth of field. A video of the solid-liquid interfaces seen in-situ and in real-time will be shown.

Flow-Centric, Back-in-Time Debugging

NASA Astrophysics Data System (ADS)

Lienhard, Adrian; Fierz, Julien; Nierstrasz, Oscar

Conventional debugging tools present developers with means to explore the run-time context in which an error has occurred. In many cases this is enough to help the developer discover the faulty source code and correct it. However, rather often errors occur due to code that has executed in the past, leaving certain objects in an inconsistent state. The actual run-time error only occurs when these inconsistent objects are used later in the program. So-called back-in-time debuggers help developers step back through earlier states of the program and explore execution contexts not available to conventional debuggers. Nevertheless, even Back-in-Time Debuggers do not help answer the question, “Where did this object come from?” The Object-Flow Virtual Machine, which we have proposed in previous work, tracks the flow of objects to answer precisely such questions, but this VM does not provide dedicated debugging support to explore faulty programs. In this paper we present a novel debugger, called Compass, to navigate between conventional run-time stack-oriented control flow views and object flows. Compass enables a developer to effectively navigate from an object contributing to an error back-in-time through all the code that has touched the object. We present the design and implementation of Compass, and we demonstrate how flow-centric, back-in-time debugging can be used to effectively locate the source of hard-to-find bugs.

Laparoscopic ileocecal resection in acute and chronic presentations of Crohn’s disease. A single center experience

PubMed Central

COCORULLO, G.; TUTINO, R.; FALCO, N.; SALAMONE, G.; FONTANA, T.; LICARI, L.; GULOTTA, G.

2016-01-01

Introduction The terminal ileum is the most involved tract in Crohn’s disease. The obstruction in this location is the most frequent complication. Acute or chronic presentations can occur. Surgery finds a role in the management of chronic strictures and in acute clinical presentations with complications not improving with conservative therapy. Patients and methods We investigate the outcome of patients with obstruction of the ileo-cecal bowel tract laparoscopically managed. It was analyzed the average operative time (OT), the conversion rate and the occurrence of re-operation due to surgical complications. Results 21 patients underwent an ileocecal resection for complicated Crohn’s disease between January 2013 and December 2014. The admissions were performed in emergency in 42% of patients. The pre-intervention hospital stay was 5.8 (Sd 6.23). The mean operative time was 154 min (Sd 41). 28% of the procedures were converted to open surgery. The average hospital stay was 10 days (Sd 5) in uncomplicated patients. The morbidity rate was 28%. In 19% of cases a re-intervention was needed due to anastomotic leakage (3pts) and one hemoperitoneum for bleeding from the suture line. Discussion Laparoscopy seems an affordable technique in the management of obstructive pattern of Crohn’s disease. It should be the preferable approach in young patients that probably will be submitted to subsequent surgery for the same disease; in fact, the reduced adhesions formation provided by the less bowel manipulation make easy the subsequent access. Older patients had usually more post-operative morbidity and mortality mostly due to pre-existing conditions; if possible in these patients the treatment should be medical. PMID:28098059

Management of cervical myelopathy due to ossification of posterior longitudinal ligament in a patient with Alström syndrome.

PubMed

Kanna, Rishi Mugesh; Gradil, Daniela; Boszczyk, Bronek M

2012-12-01

Alström syndrome (AS) is a rare autosomal recessive genetic disorder with multisystemic involvement characterised by early blindness, hearing loss, obesity, insulin resistance, diabetes mellitus, dilated cardiomyopathy, and progressive hepatic and renal dysfunction. The clinical features, time of onset and severity can vary greatly among different patients. Many of the phenotypes are often not present in infancy but develop throughout childhood and adolescence. Recessively inherited mutations in ALMS1 gene are considered to be responsible for the causation of AS. Musculoskeletal manifestations including scoliosis and kyphosis have been previously described. Here, we present a patient with AS who presented with cervical myelopathy due to extensive flowing ossification of the anterior and posterior longitudinal ligaments of the cervical spine resulting in cervical spinal cord compression. The presence of an auto-fused spine in an acceptable sagittal alignment, in the background of a constellation of medical comorbidities, which necessitated a less morbid surgical approach, favored a posterior cervical laminectomy decompression in this patient. Postoperatively, the patient showed significant neurological recovery with improved function. Follow-up MRI showed substantial enlargement of the spinal canal with improved space available for the spinal cord. The rarity of the syndrome, cervical myelopathy due to ossified posterior longitudinal ligament as a disease phenotype and the treatment considerations for performing a posterior cervical decompression have been discussed in this Grand Rounds' case presentation.

Biosensor-based real-time monitoring of paracetamol photocatalytic degradation.

PubMed

Calas-Blanchard, Carole; Istamboulié, Georges; Bontoux, Margot; Plantard, Gaël; Goetz, Vincent; Noguer, Thierry

2015-07-01

This paper presents for the first time the integration of a biosensor for the on-line, real-time monitoring of a photocatalytic degradation process. Paracetamol was used as a model molecule due to its wide use and occurrence in environmental waters. The biosensor was developed based on tyrosinase immobilization in a polyvinylalcohol photocrosslinkable polymer. It was inserted in a computer-controlled flow system installed besides a photocatalytic reactor including titanium dioxide (TiO2) as photocatalyst. It was shown that the biosensor was able to accurately monitor the paracetamol degradation with time. Compared with conventional HPLC analysis, the described device provides a real-time information on the reaction advancement, allowing a better control of the photodegradation process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nonstationary time series prediction combined with slow feature analysis

NASA Astrophysics Data System (ADS)

Wang, G.; Chen, X.

2015-01-01

Almost all climate time series have some degree of nonstationarity due to external driving forces perturbations of the observed system. Therefore, these external driving forces should be taken into account when reconstructing the climate dynamics. This paper presents a new technique of combining the driving force of a time series obtained using the Slow Feature Analysis (SFA) approach, then introducing the driving force into a predictive model to predict non-stationary time series. In essence, the main idea of the technique is to consider the driving forces as state variables and incorporate them into the prediction model. To test the method, experiments using a modified logistic time series and winter ozone data in Arosa, Switzerland, were conducted. The results showed improved and effective prediction skill.

A rating scale is a proper method to evaluate changes in quality of life due to dry eye symptoms.

PubMed

Xue, Wenwen; Xu, Xian; Zou, Haidong

2018-02-07

To determine which utility value assessment method is more suitable to evaluate changes in the quality of life due to dry eye symptoms. Dry eye outpatients with a presenting visual acuity of 20/25 or better in the worse-seeing eye were recruited. Presenting distance visual acuity, tear film break-up time, Schirmer I test and fluorescein were assessed. The severity of dry eye symptoms was assessed using the Ocular Surface Disease Index (OSDI), and utility values were measured using the time trade-off (TTO), standard gamble (SG1 and SG2) and rating scale (RS) methods. Different utility values were compared with each other. The most appropriate utility value method to evaluate quality-of-life changes solely due to dry eye symptoms is determined by calculating the correlation between the OSDI score and different utility values. A total of 104 patients were enrolled. The three sections of OSDI in the order of high to low scores were as follows: "environmental trigger," "eye discomfort" and "visual function." The utility scores measured with TTO, SG1, SG2 and RS were 0.95 ± 0.11, 0.96 ± 0.10, 0.99 ± 0.07 and 0.89 ± 0.10, respectively. The utility scores evaluated by the TTO, SG1, SG2 and RS methods were significantly different from each other (p < 0.05). Only the utility scores measured with RS were significantly correlated with the composite OSDI score, "environmental trigger" and "eye discomfort" section scores (p < 0.05). RS is more sensitive than TTO and SG for the evaluation of altered quality of life due to dry eye symptoms.

Time-dependent chemo-electro-mechanical behavior of hydrogel-based structures

NASA Astrophysics Data System (ADS)

Leichsenring, Peter; Wallmersperger, Thomas

2018-03-01

Charged hydrogels are ionic polymer gels and belong to the class of smart materials. These gels are multiphasic materials which consist of a solid phase, a fluid phase and an ionic phase. Due to the presence of bound charges these materials are stimuli-responsive to electrical or chemical loads. The application of electrical or chemical stimuli as well as mechanical loads lead to a viscoelastic response. On the macroscopic scale, the response is governed by a local reversible release or absorption of water which, in turn, leads to a local decrease or increase of mass and a respective volume change. Furthermore, the chemo-electro-mechanical equilibrium of a hydrogel depends on the chemical composition of the gel and the surrounding solution bath. Due to the presence of bound charges in the hydrogel, this system can be understood as an osmotic cell where differences in the concentration of mobile ions in the gel and solution domain lead to an osmotic pressure difference. In the present work, a continuum-based numerical model is presented in order to describe the time-dependent swelling behavior of hydrogels. The numerical model is based on the Theory of Porous Media and captures the fluid-solid, fluid-ion and ion-ion interactions. As a direct consequence of the chemo-electro-mechanical equilibrium, the corresponding boundary conditions are defined following the equilibrium conditions. For the interaction of the hydrogel with surrounding mechanical structures, also respective jump condtions are formulated. Finaly, numerical results of the time-dependent behavior of a hydrogel-based chemo-sensor will be presented.

Drawing the line on the sand

NASA Astrophysics Data System (ADS)

Ranasinghe, R.; Jongejan, R.; Wainwright, D.; Callaghan, D. P.

2016-02-01

Up to 70% of the world's sandy coastlines are eroding, resulting in gradual and continuous coastline recession. The rate of coastline recession is likely to increase due to the projected impacts of climate change on mean sea levels, offshore wave climate and storm surges. At the same time, rapid development in the world's coastal zones continues to increase potential damages, while often reducing the resilience of coastal systems. The risks associated with coastline recession are thus likely to increase over the coming decades, unless effective risk management plans are put in place. Land-use restrictions are a key component of coastal zone risk management plans. These involve the use of coastal setback lines which are mainly established by linearly adding the impacts of storms, recession due to sea level rise, and ambient long term trends in shoreline evolution. This approach does not differentiate between uncertainties that develop differently over time, nor takes into account the value and lifetime of property developments. Both shortcomings could entail considerable social cost. For balancing risk and reward, probabilistic estimates of coastline recession are a pre-requisite. Yet the presently adopted deterministic methods for establishing setback lines are unable to provide such estimates. Here, we present a quantitative risk analysis (QRA) model, underpinned by a multi-scale, physics based coastal recession model capable of providing time-dependent risk estimates. The modelling approach presented enables the determination of setback lines in terms of exceedance probabilities, a quantity that directly feeds into risk evaluations and economic optimizations. As a demonstration, the risk-informed approach is applied to Narrabeen beach, Sydney, Australia.

Real-Time View Correction for Mobile Devices.

PubMed

Schops, Thomas; Oswald, Martin R; Speciale, Pablo; Yang, Shuoran; Pollefeys, Marc

2017-11-01

We present a real-time method for rendering novel virtual camera views from given RGB-D (color and depth) data of a different viewpoint. Missing color and depth information due to incomplete input or disocclusions is efficiently inpainted in a temporally consistent way. The inpainting takes the location of strong image gradients into account as likely depth discontinuities. We present our method in the context of a view correction system for mobile devices, and discuss how to obtain a screen-camera calibration and options for acquiring depth input. Our method has use cases in both augmented and virtual reality applications. We demonstrate the speed of our system and the visual quality of its results in multiple experiments in the paper as well as in the supplementary video.

Ultra Wide-Band Localization and SLAM: A Comparative Study for Mobile Robot Navigation

PubMed Central

Segura, Marcelo J.; Auat Cheein, Fernando A.; Toibero, Juan M.; Mut, Vicente; Carelli, Ricardo

2011-01-01

In this work, a comparative study between an Ultra Wide-Band (UWB) localization system and a Simultaneous Localization and Mapping (SLAM) algorithm is presented. Due to its high bandwidth and short pulses length, UWB potentially allows great accuracy in range measurements based on Time of Arrival (TOA) estimation. SLAM algorithms recursively estimates the map of an environment and the pose (position and orientation) of a mobile robot within that environment. The comparative study presented here involves the performance analysis of implementing in parallel an UWB localization based system and a SLAM algorithm on a mobile robot navigating within an environment. Real time results as well as error analysis are also shown in this work. PMID:22319397

Large-scale frequency- and time-domain quantum entanglement over the optical frequency comb (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pfister, Olivier

2017-05-01

When it comes to practical quantum computing, the two main challenges are circumventing decoherence (devastating quantum errors due to interactions with the environmental bath) and achieving scalability (as many qubits as needed for a real-life, game-changing computation). We show that using, in lieu of qubits, the "qumodes" represented by the resonant fields of the quantum optical frequency comb of an optical parametric oscillator allows one to create bona fide, large scale quantum computing processors, pre-entangled in a cluster state. We detail our recent demonstration of 60-qumode entanglement (out of an estimated 3000) and present an extension to combining this frequency-tagged with time-tagged entanglement, in order to generate an arbitrarily large, universal quantum computing processor.

A three-dimensional spin-diffusion model for micromagnetics

PubMed Central

Abert, Claas; Ruggeri, Michele; Bruckner, Florian; Vogler, Christoph; Hrkac, Gino; Praetorius, Dirk; Suess, Dieter

2015-01-01

We solve a time-dependent three-dimensional spin-diffusion model coupled to the Landau-Lifshitz-Gilbert equation numerically. The presented model is validated by comparison to two established spin-torque models: The model of Slonzewski that describes spin-torque in multi-layer structures in the presence of a fixed layer and the model of Zhang and Li that describes current driven domain-wall motion. It is shown that both models are incorporated by the spin-diffusion description, i.e., the nonlocal effects of the Slonzewski model are captured as well as the spin-accumulation due to magnetization gradients as described by the model of Zhang and Li. Moreover, the presented method is able to resolve the time dependency of the spin-accumulation. PMID:26442796

Social media interruption affects the acquisition of visually, not aurally, acquired information during a pathophysiology lecture.

PubMed

Marone, Jane R; Thakkar, Shivam C; Suliman, Neveen; O'Neill, Shannon I; Doubleday, Alison F

2018-06-01

Poor academic performance from extensive social media usage appears to be due to students' inability to multitask between distractions and academic work. However, the degree to which visually distracted students can acquire lecture information presented aurally is unknown. This study examined the ability of students visually distracted by social media to acquire information presented during a voice-over PowerPoint lecture, and to compare performance on examination questions derived from information presented aurally vs. that presented visually. Students ( n = 20) listened to a 42-min cardiovascular pathophysiology lecture containing embedded cartoons while taking notes. The experimental group ( n = 10) was visually, but not aurally, distracted by social media during times when cartoon information was presented, ~40% of total lecture time. Overall performance among distracted students on a follow-up, open-note quiz was 30% poorer than that for controls ( P < 0.001). When the modality of presentation (visual vs. aural) was compared, performance decreased on examination questions from information presented visually. However, performance on questions from information presented aurally was similar to that of controls. Our findings suggest the ability to acquire information during lecture may vary, depending on the degree of competition between the modalities of the distraction and the lecture presentation. Within the context of current literature, our findings also suggest that timing of the distraction relative to delivery of material examined affects performance more than total distraction time. Therefore, when delivering lectures, instructors should incorporate organizational cues and active learning strategies that assist students in maintaining focus and acquiring relevant information.

Radar error statistics for the space shuttle

NASA Technical Reports Server (NTRS)

Lear, W. M.

1979-01-01

Radar error statistics of C-band and S-band that are recommended for use with the groundtracking programs to process space shuttle tracking data are presented. The statistics are divided into two parts: bias error statistics, using the subscript B, and high frequency error statistics, using the subscript q. Bias errors may be slowly varying to constant. High frequency random errors (noise) are rapidly varying and may or may not be correlated from sample to sample. Bias errors were mainly due to hardware defects and to errors in correction for atmospheric refraction effects. High frequency noise was mainly due to hardware and due to atmospheric scintillation. Three types of atmospheric scintillation were identified: horizontal, vertical, and line of sight. This was the first time that horizontal and line of sight scintillations were identified.

Shock timing measurements and analysis in deuterium-tritium-ice layered capsule implosions on NIF

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

Robey, H. F.; Celliers, P. M.; Moody, J. D.

2014-02-15

Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion implosions [Boehly et al., Phys. Rev. Lett. 106, 195005 (2011); Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs.more » DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. Comparison of the data with simulation shows good agreement for the timing of the first three shocks, but reveals a considerable discrepancy in the timing of the 4th shock in DT ice layered implosions. Electron preheat is examined as a potential cause of the observed discrepancy in the 4th shock timing.« less

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

Kim, K. S.; Nakae, L. F.; Prasad, M. K.

Here, we solve a simple theoretical model of time evolving fission chains due to Feynman that generalizes and asymptotically approaches the point model theory. The point model theory has been used to analyze thermal neutron counting data. This extension of the theory underlies fast counting data for both neutrons and gamma rays from metal systems. Fast neutron and gamma-ray counting is now possible using liquid scintillator arrays with nanosecond time resolution. For individual fission chains, the differential equations describing three correlated probability distributions are solved: the time-dependent internal neutron population, accumulation of fissions in time, and accumulation of leaked neutronsmore » in time. Explicit analytic formulas are given for correlated moments of the time evolving chain populations. The equations for random time gate fast neutron and gamma-ray counting distributions, due to randomly initiated chains, are presented. Correlated moment equations are given for both random time gate and triggered time gate counting. There are explicit formulas for all correlated moments are given up to triple order, for all combinations of correlated fast neutrons and gamma rays. The nonlinear differential equations for probabilities for time dependent fission chain populations have a remarkably simple Monte Carlo realization. A Monte Carlo code was developed for this theory and is shown to statistically realize the solutions to the fission chain theory probability distributions. Combined with random initiation of chains and detection of external quanta, the Monte Carlo code generates time tagged data for neutron and gamma-ray counting and from these data the counting distributions.« less

Generalized Elliott-Yafet spin-relaxation time for arbitrary spin mixing

NASA Astrophysics Data System (ADS)

Vollmar, Svenja; Hilton, David J.; Schneider, Hans Christian

2017-08-01

We extend our recent result for the spin-relaxation time due to acoustic electron-phonon scattering in degenerate bands with spin mixing [New J. Phys. 18, 023012 (2016), 10.1088/1367-2630/18/2/023012] to include interactions with optical phonons, and present a numerical evaluation of the spin-relaxation time for intraband hole-phonon scattering in the heavy-hole (HH) bands of bulk GaAs. Comparing our computed spin-relaxation times to the conventional Elliott-Yafet result quantitatively demonstrates that the latter underestimates the spin-relaxation time because it does not correctly describe how electron-phonon interactions change the (vector) spin expectation value of the single-particle states. We show that the conventional Elliott-Yafet spin relaxation time is a special case of our result for weak spin mixing.

Scheduling job shop - A case study

NASA Astrophysics Data System (ADS)

Abas, M.; Abbas, A.; Khan, W. A.

2016-08-01

The scheduling in job shop is important for efficient utilization of machines in the manufacturing industry. There are number of algorithms available for scheduling of jobs which depend on machines tools, indirect consumables and jobs which are to be processed. In this paper a case study is presented for scheduling of jobs when parts are treated on available machines. Through time and motion study setup time and operation time are measured as total processing time for variety of products having different manufacturing processes. Based on due dates different level of priority are assigned to the jobs and the jobs are scheduled on the basis of priority. In view of the measured processing time, the times for processing of some new jobs are estimated and for efficient utilization of the machines available an algorithm is proposed and validated.

Substrate-Limited Saccharomyces cerevisiae Yeast Strains Allow Control of Fermentation during Bread Making.

PubMed

Struyf, Nore; Laurent, Jitka; Verspreet, Joran; Verstrepen, Kevin J; Courtin, Christophe M

2017-04-26

Identification and use of yeast strains that are unable to consume one or more otherwise fermentable substrate types could allow a more controlled fermentation process with more flexibility regarding fermentation times. In this study, Saccharomyces cerevisiae strains with different capacities to consume substrates present in wheat were selected to investigate the impact of substrate limitation on dough fermentation and final bread volume. Results show that fermentation of dough with maltose-negative strains relies on the presence of fructan and sucrose as fermentable substrates and can be used for regular bread making. Levels of fructan and sucrose, endogenously present or added, hence determine the extent of fermentation and timing at the proofing stage. Whole meal is inherently more suitable for substrate-limited fermentation than white flour due to the presence of higher native levels of these substrates. Bread making protocols with long fermentation times are accommodated by addition of substrates such as sucrose.

Remediation of sandy soils contaminated with hydrocarbons and halogenated hydrocarbons by soil vapour extraction.

PubMed

Albergaria, José Tomás; Alvim-Ferraz, Maria da Conceição M; Delerue-Matos, Cristina

2012-08-15

This paper presents the study of the remediation of sandy soils containing six of the most common contaminants (benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene) using soil vapour extraction (SVE). The influence of soil water content on the process efficiency was evaluated considering the soil type and the contaminant. For artificially contaminated soils with negligible clay contents and natural organic matter it was concluded that: (i) all the remediation processes presented efficiencies above 92%; (ii) an increase of the soil water content led to a more time-consuming remediation; (iii) longer remediation periods were observed for contaminants with lower vapour pressures and lower water solubilities due to mass transfer limitations. Based on these results an easy and relatively fast procedure was developed for the prediction of the remediation times of real soils; 83% of the remediation times were predicted with relative deviations below 14%. Copyright © 2012 Elsevier Ltd. All rights reserved.

Encounter times of chromatin loci influenced by polymer decondensation

NASA Astrophysics Data System (ADS)

Amitai, A.; Holcman, D.

2018-03-01

The time for a DNA sequence to find its homologous counterpart depends on a long random search inside the cell nucleus. Using polymer models, we compute here the mean first encounter time (MFET) between two sites located on two different polymer chains and confined locally by potential wells. We find that reducing tethering forces acting on the polymers results in local decondensation, and numerical simulations of the polymer model show that these changes are associated with a reduction of the MFET by several orders of magnitude. We derive here new asymptotic formula for the MFET, confirmed by Brownian simulations. We conclude from the present modeling approach that the fast search for homology is mediated by a local chromatin decondensation due to the release of multiple chromatin tethering forces. The present scenario could explain how the homologous recombination pathway for double-stranded DNA repair is controlled by its random search step.

Complete elimination of the secondary electron background in Auger spectra using Time of Flight Positron Annihilation Induced Auger Electron Spectroscopy

NASA Astrophysics Data System (ADS)

Joglekar, Prasad; Shastry, Karthik; Kalaskar, Sushant; Satyal, Suman; Lim, L.; Weiss, Alexander

2010-03-01

Time of flight- positron annihilation induced Auger electron spectroscopy (TOF-PAES) is a surface analysis technique with high surface selectivity. Almost 95% of the TOF-PAES signal emerges from the topmost layer of the sample due to the trapping of positrons in an image-potential-well before annihilation. In this poster we will present new results that demonstrate how very low energy positron beams can be used together with the time of Flight (TOF) technique developed at The University of Texas at Arlington to obtain Auger spectra that are completely free of secondary electron background.

Fast parallel approach for 2-D DHT-based real-valued discrete Gabor transform.

PubMed

Tao, Liang; Kwan, Hon Keung

2009-12-01

Two-dimensional fast Gabor transform algorithms are useful for real-time applications due to the high computational complexity of the traditional 2-D complex-valued discrete Gabor transform (CDGT). This paper presents two block time-recursive algorithms for 2-D DHT-based real-valued discrete Gabor transform (RDGT) and its inverse transform and develops a fast parallel approach for the implementation of the two algorithms. The computational complexity of the proposed parallel approach is analyzed and compared with that of the existing 2-D CDGT algorithms. The results indicate that the proposed parallel approach is attractive for real time image processing.

Direct and continuous synthesis of VO2 nanoparticles

NASA Astrophysics Data System (ADS)

Powell, M. J.; Marchand, P.; Denis, C. J.; Bear, J. C.; Darr, J. A.; Parkin, I. P.

2015-11-01

Monoclinic VO2 nanoparticles are of interest due to the material's thermochromic properties, however, direct synthesis routes to VO2 nanoparticles are often inaccessible due to the high synthesis temperatures or long reaction times required. Herein, we present a two-step synthesis route for the preparation of monoclinic VO2 nanoparticles using Continuous Hydrothermal Flow Synthesis (CHFS) followed by a short post heat treatment step. A range of particle sizes, dependent on synthesis conditions, were produced from 50 to 200 nm by varying reaction temperatures and the residence times in the process. The nanoparticles were characterised by powder X-ray diffraction, Raman and UV/Vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The nanoparticles were highly crystalline with rod and sphere-like morphologies present in TEM micrographs, with the size of both the rod and spherical particles being highly dependent on both reaction temperature and residence time. SEM micrographs showed the surface of the powders produced from the CHFS process to be highly uniform. The samples were given a short post synthesis heat treatment to ensure that they were phase pure monoclinic VO2, which led to them exhibiting a large and reversible switch in optical properties (at near-IR wavelengths), which suggests that if such materials can be incorporated into coatings or in composites, they could be used for fenestration in architectural applications.

Direct and continuous synthesis of VO2 nanoparticles.

PubMed

Powell, M J; Marchand, P; Denis, C J; Bear, J C; Darr, J A; Parkin, I P

2015-11-28

Monoclinic VO2 nanoparticles are of interest due to the material's thermochromic properties, however, direct synthesis routes to VO2 nanoparticles are often inaccessible due to the high synthesis temperatures or long reaction times required. Herein, we present a two-step synthesis route for the preparation of monoclinic VO2 nanoparticles using Continuous Hydrothermal Flow Synthesis (CHFS) followed by a short post heat treatment step. A range of particle sizes, dependent on synthesis conditions, were produced from 50 to 200 nm by varying reaction temperatures and the residence times in the process. The nanoparticles were characterised by powder X-ray diffraction, Raman and UV/Vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The nanoparticles were highly crystalline with rod and sphere-like morphologies present in TEM micrographs, with the size of both the rod and spherical particles being highly dependent on both reaction temperature and residence time. SEM micrographs showed the surface of the powders produced from the CHFS process to be highly uniform. The samples were given a short post synthesis heat treatment to ensure that they were phase pure monoclinic VO2, which led to them exhibiting a large and reversible switch in optical properties (at near-IR wavelengths), which suggests that if such materials can be incorporated into coatings or in composites, they could be used for fenestration in architectural applications.

Using Words Instead of Jumbled Characters as Stimuli in Keyboard Training Facilitates Fluent Performance

ERIC Educational Resources Information Center

DeFulio, Anthony; Crone-Todd, Darlene E.; Long, Lauren V.; Nuzzo, Paul A.; Silverman, Kenneth

2011-01-01

Keyboarding skill is an important target for adult education programs due to the ubiquity of computers in modern work environments. A previous study showed that novice typists learned key locations quickly but that fluency took a relatively long time to develop. In the present study, novice typists achieved fluent performance in nearly half the…

Internet Use and Video Gaming Predict Problem Behavior in Early Adolescence

ERIC Educational Resources Information Center

Holtz, Peter; Appel, Markus

2011-01-01

In early adolescence, the time spent using the Internet and video games is higher than in any other present-day age group. Due to age-inappropriate web and gaming content, the impact of new media use on teenagers is a matter of public and scientific concern. Based on current theories on inappropriate media use, a study was conducted that comprised…

Determinants of Social Networking Software Acceptance: A Multi-Theoretical Approach

ERIC Educational Resources Information Center

Shittu, Ahmed Tajudeen; Madarsha, Kamal Basha; AbduRahman, Nik Suryani Nik; Ahmad, Tunku Badariah Tunku

2013-01-01

Understanding reasons why students use social media has become a major preoccupation of researchers in recent time due to the rate of its adoption among the present generation of students. Some of the few study on social media phenomenon employed a single theory as a framework in order to understand the factors that influence the acceptance of it…

Supramolecular binding and release of sulfide and hydrosulfide anions in water.

PubMed

Vázquez, J; Sindelar, V

2018-06-05

Hydrogen sulfide (H2S) has become an important target for research due to its physiological properties as well as its potential applications in medicine. In this work, supramolecular binding of sulfide (S2-) and hydrosulfide (HS-) anions in water is presented for the first time. Bambusurils were used to slow down the release of these anions in water.

Time Evolution of Radiation-Induced Luminescence in Terbium-Doped Silicate Glass

NASA Technical Reports Server (NTRS)

West, Michael S.; Winfree, William P.

1996-01-01

A study was made on two commercially available terbium-doped silicate glasses. There is an increased interest in silicate glasses doped with rare-earth ions for use in high-energy particle detection and radiographic applications. These glasses are of interest due to the fact that they can be formed into small fiber sensors; a property that can be used to increase the spatial resolution of a detection system. Following absorption of radiation, the terbium ions become excited and then emit photons via 4f-4f electronic transitions as they relax back to the ground state. The lifetime of these transitions is on the order of milliseconds. A longer decay component lasting on the order of minutes has also been observed. While radiative transitions in the 4f shell of rare-earth ions are generally well understood by the Judd-Olfelt theory, the pr'esence of a longer luminescence decay component is not. Experimental evidence that the long decay component is due, in part, to the thermal release of trapped charge carriers will be presented. In addition, a theoretical model describing the time evolution of the radiation-induced luminescence will be presented.

Earthquake clouds and physical mechanism of their formation.

NASA Astrophysics Data System (ADS)

Doda, L.; Pulinets, S.

2006-12-01

The Lithosphere-Atmosphere-Ionosphere (LAI) coupling model created recently permitted to explain some unknown phenomena observed around the time of strong earthquakes. One of them is formation of special shape clouds, usually presented as the thin linear structures. It was discovered that these clouds are associated with the active tectonic faults or with the tectonic plate borders. They repeat the fault shape but usually are turned in relation to the fault position. Their formation is explained by the anomalous vertical electric field generated in the vicinity of active tectonic structure due to air ionization produced by the radon increased emanation. The new formed ions through the hydration process do not recombine and growth with time due to increased water molecules attachment to the ion. Simultaneously they move up driven by the anomalous electric field and drift in the crossed ExB fields. At the higher altitudes the large ion clusters become the centers of condensation and the cloud formation. Examples for the recent major earthquakes (Sumatra 2004, Kashmir 2005, Java 2006) are presented. The size and the angle of the cloud rotation in relation to the fault position permit to estimate the magnitude of the impending earthquake.

Effect of substrate roughness on the corrosion behaviour of the Al2O3/MA 956 system.

PubMed

García-Alonso, M C; Escudero, M L; González-Carrasco, J L; Chao, J

2000-01-01

This paper presents the influence of substrate roughness on the corrosion behaviour of the Al2O3/MA 956 system. An alumina layer of thickness 1-5 microm was generated of the MA956 alloy by thermal oxidation at 1100 degrees C using different exposure times. This Al2O3/MA 956 system with a polished substrate has shown excellent corrosion behaviour in a physiological fluid, due to the fact that the alpha-Al2O3 layer formed is dense, continuous and firmly adhered to the substrate, irrespective of the scale thickness. This good adherence allows it to withstand potentials above 1.7 V. Specimens with rough finish substrate and treatment times above 10 h present spallation of the alumina layer at the crests of the roughness profile. In this case a mixed corrosion behaviour between an alumina coated material and one with a passive layer is observed. In both types of specimens, rough and smooth, once the passivation layer is broken the repassivation capacity of the substrate is ensured due to the high chromium content of the alloy, under oxygenation conditions.

An incremental anomaly detection model for virtual machines.

PubMed

Zhang, Hancui; Chen, Shuyu; Liu, Jun; Zhou, Zhen; Wu, Tianshu

2017-01-01

Self-Organizing Map (SOM) algorithm as an unsupervised learning method has been applied in anomaly detection due to its capabilities of self-organizing and automatic anomaly prediction. However, because of the algorithm is initialized in random, it takes a long time to train a detection model. Besides, the Cloud platforms with large scale virtual machines are prone to performance anomalies due to their high dynamic and resource sharing characters, which makes the algorithm present a low accuracy and a low scalability. To address these problems, an Improved Incremental Self-Organizing Map (IISOM) model is proposed for anomaly detection of virtual machines. In this model, a heuristic-based initialization algorithm and a Weighted Euclidean Distance (WED) algorithm are introduced into SOM to speed up the training process and improve model quality. Meanwhile, a neighborhood-based searching algorithm is presented to accelerate the detection time by taking into account the large scale and high dynamic features of virtual machines on cloud platform. To demonstrate the effectiveness, experiments on a common benchmark KDD Cup dataset and a real dataset have been performed. Results suggest that IISOM has advantages in accuracy and convergence velocity of anomaly detection for virtual machines on cloud platform.

An incremental anomaly detection model for virtual machines

PubMed Central

Zhang, Hancui; Chen, Shuyu; Liu, Jun; Zhou, Zhen; Wu, Tianshu

2017-01-01

Self-Organizing Map (SOM) algorithm as an unsupervised learning method has been applied in anomaly detection due to its capabilities of self-organizing and automatic anomaly prediction. However, because of the algorithm is initialized in random, it takes a long time to train a detection model. Besides, the Cloud platforms with large scale virtual machines are prone to performance anomalies due to their high dynamic and resource sharing characters, which makes the algorithm present a low accuracy and a low scalability. To address these problems, an Improved Incremental Self-Organizing Map (IISOM) model is proposed for anomaly detection of virtual machines. In this model, a heuristic-based initialization algorithm and a Weighted Euclidean Distance (WED) algorithm are introduced into SOM to speed up the training process and improve model quality. Meanwhile, a neighborhood-based searching algorithm is presented to accelerate the detection time by taking into account the large scale and high dynamic features of virtual machines on cloud platform. To demonstrate the effectiveness, experiments on a common benchmark KDD Cup dataset and a real dataset have been performed. Results suggest that IISOM has advantages in accuracy and convergence velocity of anomaly detection for virtual machines on cloud platform. PMID:29117245

Direct hyperpolarization of micro- and nanodiamonds for bioimaging applications - Considerations on particle size, functionalization and polarization loss.

PubMed

Kwiatkowski, Grzegorz; Jähnig, Fabian; Steinhauser, Jonas; Wespi, Patrick; Ernst, Matthias; Kozerke, Sebastian

2018-01-01

Due to the inherently long relaxation time of 13 C spins in diamond, the nuclear polarization enhancement obtained with dynamic nuclear polarization can be preserved for a time on the order of about one hour, opening up an opportunity to use diamonds as a new class of long-lived contrast agents. The present communication explores the feasibility of using 13 C spins in directly hyperpolarized diamonds for MR imaging including considerations for potential in vivo applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Continuous real-time measurement of aqueous cyanide

DOEpatents

Rosentreter, Jeffrey J.; Gering, Kevin L.

2007-03-06

This invention provides a method and system capable of the continuous, real-time measurement of low concentrations of aqueous free cyanide (CN) using an on-line, flow through system. The system is based on the selective reactivity of cyanide anions and the characteristically nonreactive nature of metallic gold films, wherein this selective reactivity is exploited as an indirect measurement for aqueous cyanide. In the present invention the dissolution of gold, due to the solubilization reaction with the analyte cyanide anion, is monitored using a piezoelectric microbalance contained within a flow cell.

Ground systems and operations concepts for the Space Infrared Telescope Facility (SIRTF)

NASA Technical Reports Server (NTRS)

Miller, Richard B.

1991-01-01

Key requirements and ground systems implementation strategy for SIRTF which presents a significant challenge in the operational phase of the mission are discussed. The facility is aimed at reliably integrating a guaranteed time program, requests from about 200 guest observer teams per year, and observatory maintenance. SIRFT is characterized by the five-year life time due to cryogen boil-off which means that the ground system must be fully operational at launch and must operate with an efficiency and timeliness rarely achieved in previous space missions.

Study of Real-Time Dry Bulb and Relative Humidity Sensors in Underground Coal Mines

NASA Astrophysics Data System (ADS)

Khanal, Manoj; McPhee, Ron; Belle, Bharath; Brisbane, Peter; Kathage, Bevan

2016-12-01

As the depth of mines increases, the temperature in the mine workings also increases due to the geothermal gradient. A questionnaire was prepared and sent to a number of mine ventilation engineers, consultants and academics in order to gain an understanding of their experiences and current views on real-time dry and relative humidity temperature monitoring practices. Eighteen persons provided a response to the questionnaire. The answers were compiled and analyzed. This paper presents and analyzed the results obtained from the survey.

Some interesting aspects of physisorption stay-time measurements obtained using molecular-beam techniques. [on Ni surface

NASA Technical Reports Server (NTRS)

Wilmoth, R. G.; Fisher, S. S.

1974-01-01

Stay-time distributions have been obtained for Xe physisorbing on polycrystalline nickel as a function of the target temperature using a pulsed molecular-beam technique. Some interesting effects due to ion bombardment of the surface using He, Ar, and Xe ions are presented. Measured detector signal shapes are found to deviate from those predicted for first-order desorption with velocities corresponding to Maxwellian effusion at the surface temperature. Evidence is found for interaction between beam pulse adsorption and steady-state adsorption of beam species background atoms.

Damage Detection in Railway Prestressed Concrete Sleepers using Acoustic Emission

NASA Astrophysics Data System (ADS)

Clark, A.; Kaewunruen, S.; Janeliukstis, R.; Papaelias, M.

2017-10-01

Prestressed concrete sleepers (or railroad ties) are safety-critical elements in railway tracks that distribute the wheel loads from the rails to the track support system. Over a period of time, the concrete sleepers age and deteriorate in addition to experiencing various types of static and dynamic loading conditions, which are attributable to train operations. In many cases, structural cracks can develop within the sleepers due to high intensity impact loads or due to poor track maintenance. Often, cracks of sleepers develop and present at the midspan due to excessive negative bending. These cracks can cause broken sleepers and sometimes called ‘center bound’ problem in railway lines. This paper is the world first to present an application of non-destructive acoustic emission technology for damage detection in railway concrete sleepers. It presents experimental investigations in order to detect center-bound cracks in railway prestressed concrete sleepers. Experimental laboratory testing involves three-point bending tests of four concrete sleepers. Three-point bending tests correspond to a real failure mode, when the loads are not transferred uniformly to the ballast support. It is observed that AE sensing provides an accurate means for detecting the location and magnitude of cracks in sleepers. Sensor location criticality is also highlighted in the paper to demonstrate the reliability-based damage detection of the sleepers.

Performances of BNL high-intensity synchrotrons

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

Weng, W.T.

1998-03-01

The AGS proton synchrotron was completed in 1960 with initial intensity in the 10 to the 10th power proton per pulse (ppp) range. Over the years, through many upgrades and improvements, the AGS now reached an intensity record of 6.3 {times} 10{sup 13} ppp, the highest world intensity record for a proton synchrotron on a single pulse basis. At the same time, the Booster reached 2.2 {times} 10{sup 13} ppp surpassing the design goal of 1.5 {times} 10{sup 13} ppp due to the introduction of second harmonic cavity during injection. The intensity limitation caused by space charge tune spread andmore » its relationship to injection energy at 50 MeV, 200 MeV, and 1,500 MeV will be presented as well as many critical accelerator manipulations. BNL currently participates in the design of an accumulator ring for the SNS project at Oak Ridge. The status on the issues of halo formation, beam losses and collimation are also presented.« less

Resource-constrained scheduling with hard due windows and rejection penalties

NASA Astrophysics Data System (ADS)

Garcia, Christopher

2016-09-01

This work studies a scheduling problem where each job must be either accepted and scheduled to complete within its specified due window, or rejected altogether. Each job has a certain processing time and contributes a certain profit if accepted or penalty cost if rejected. There is a set of renewable resources, and no resource limit can be exceeded at any time. Each job requires a certain amount of each resource when processed, and the objective is to maximize total profit. A mixed-integer programming formulation and three approximation algorithms are presented: a priority rule heuristic, an algorithm based on the metaheuristic for randomized priority search and an evolutionary algorithm. Computational experiments comparing these four solution methods were performed on a set of generated benchmark problems covering a wide range of problem characteristics. The evolutionary algorithm outperformed the other methods in most cases, often significantly, and never significantly underperformed any method.

Kinetics of sub-spinodal dewetting of thin films of thickness dependent viscosity.

PubMed

Kotni, Tirumala Rao; Khanna, Rajesh; Sarkar, Jayati

2017-05-04

An alternative explanation of the time varying and very low growth exponents in dewetting of polymer films like polystyrene films is presented based on non-linear simulations. The kinetics of these films is explored within the framework of experimentally observed thickness dependent viscosity. These films exhibit sub-spinodal dewetting via formation of satellite holes in between primary dewetted holes under favorable conditions of excess intermolecular forces and film thicknesses. We find that conditions responsible for sub-spinodal dewetting concurrently lead to remarkable changes in the kinetics of dewetting of even primary holes. For example, the radius of the hole grows in time with a power-law growth exponent sequence of [Formula: see text], in contrast to the usual  ∼4/5. This is due to the cumulative effect of reduced rim mobility due to thickness dependent viscosity and hindrance created by satellite holes.

A Microsystem Based on Porous Silicon-Glass Anodic Bonding for Gas and Liquid Optical Sensing

PubMed Central

De Stefano, Luca; Malecki, Krzysztof; Della Corte, Francesco G.; Moretti, Luigi; Rea, Ilaria; Rotiroti, Lucia; Rendina, Ivo

2006-01-01

We have recently presented an integrated silicon-glass opto-chemical sensor for lab-on-chip applications, based on porous silicon and anodic bonding technologies. In this work, we have optically characterized the sensor response on exposure to vapors of several organic compounds by means of reflectivity measurements. The interaction between the porous silicon, which acts as transducer layer, and the organic vapors fluxed into the glass sealed microchamber, is preserved by the fabrication process, resulting in optical path increase, due to the capillary condensation of the vapors into the pores. Using the Bruggemann theory, we have calculated the filled pores volume for each substance. The sensor dynamic has been described by time-resolved measurements: due to the analysis chamber miniaturization, the response time is only of 2 s. All these results have been compared with data acquired on the same PSi structure before the anodic bonding process.

Civil helicopter propulsion system reliability and engine monitoring technology assessments

NASA Technical Reports Server (NTRS)

Murphy, J. A.; Zuk, J.

1982-01-01

A study to reduce operating costs of helicopters, particularly directed at the maintenance of the propulsion subsystem, is presented. The tasks of the study consisted of problem definition refinement, technology solutions, diagnostic system concepts, and emergency power augmentation. Quantifiable benefits (reduced fuel consumption, on-condition engine maintenance, extended drive system overhaul periods, and longer oil change intervals) would increase the initial cost by $43,000, but the benefit of $24.46 per hour would result in breakeven at 1758 hours. Other benefits not capable of being quantified but perhaps more important include improved aircraft avilability due to reduced maintenance time, potential for increased operating limits due to continuous automatic monitoring of gages, and less time and fuel required to make engine power checks. The most important improvement is the on-condition maintenance program, which will require the development of algorithms, equipment, and procedures compatible with all operating environments.

Using pattern analysis methods to do fast detection of manufacturing pattern failures

NASA Astrophysics Data System (ADS)

Zhao, Evan; Wang, Jessie; Sun, Mason; Wang, Jeff; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua

2016-03-01

At the advanced technology node, logic design has become extremely complex and is getting more challenging as the pattern geometry size decreases. The small sizes of layout patterns are becoming very sensitive to process variations. Meanwhile, the high pressure of yield ramp is always there due to time-to-market competition. The company that achieves patterning maturity earlier than others will have a great advantage and a better chance to realize maximum profit margins. For debugging silicon failures, DFT diagnostics can identify which nets or cells caused the yield loss. But normally, a long time period is needed with many resources to identify which failures are due to one common layout pattern or structure. This paper will present a new yield diagnostic flow, based on preliminary EFA results, to show how pattern analysis can more efficiently detect pattern related systematic defects. Increased visibility on design pattern related failures also allows more precise yield loss estimation.

INFRARED OBSERVATIONAL MANIFESTATIONS OF YOUNG DUSTY SUPER STAR CLUSTERS

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

Martínez-González, Sergio; Tenorio-Tagle, Guillermo; Silich, Sergiy, E-mail: sergiomtz@inaoep.mx

The growing evidence pointing at core-collapse supernovae as large dust producers makes young massive stellar clusters ideal laboratories to study the evolution of dust immersed in a hot plasma. Here we address the stochastic injection of dust by supernovae, and follow its evolution due to thermal sputtering within the hot and dense plasma generated by young stellar clusters. Under these considerations, dust grains are heated by means of random collisions with gas particles which result in the appearance of  infrared spectral signatures. We present time-dependent infrared spectral energy distributions that are to be expected from young stellar clusters. Our results aremore » based on hydrodynamic calculations that account for the stochastic injection of dust by supernovae. These also consider gas and dust radiative cooling, stochastic dust temperature fluctuations, the exit of dust grains out of the cluster volume due to the cluster wind, and a time-dependent grain size distribution.« less

Electrodeposition of Metals in Microgravity Conditions

NASA Technical Reports Server (NTRS)

Nishikawa, K.; Homma, T.; Chassaing, E.; Rosso, M.; Fukunaka, Y.

2012-01-01

Metal electrodeposition may introduce various morphological variations depending on the electrolytic conditions including cell configurations. For liquid electrolytes, a precise study of these deposits may be complicated by convective motion due to buoyancy. Zero-gravity (0-G) condition provided by drop shaft or parabolic flight gives a straightforward mean to avoid this effect: we present here 0-G electrodeposition experiments, which we compare to ground experiments (1-G). Two electrochemical systems were studied by laser interferometry, allowing to measure the concentration variations in the electrolyte: copper deposition from copper sulfate aqueous solution and lithium deposition from an ionic liquid containing LiTFSI. For copper, concentration variations were in good agreement with theory. For lithium, an apparent induction time was observed for the concentration evolution at 1-G: due to this induction time and to the low diffusion coefficient in ionic liquid, the concentration variations were hardly measurable in the parabolic flight 0-G periods of 20 seconds.

Toroidal Ampere-Faraday Equations Solved Consistently with the CQL3D Fokker-Planck Time-Evolution

NASA Astrophysics Data System (ADS)

Harvey, R. W.; Petrov, Yu. V.

2013-10-01

A self-consistent, time-dependent toroidal electric field calculation is a key feature of a complete 3D Fokker-Planck kinetic distribution radial transport code for f(v,theta,rho,t). In the present CQL3D finite-difference model, the electric field E(rho,t) is either prescribed, or iteratively adjusted to obtain prescribed toroidal or parallel currents. We discuss first results of an implementation of the Ampere-Faraday equation for the self-consistent toroidal electric field, as applied to the runaway electron production in tokamaks due to rapid reduction of the plasma temperature as occurs in a plasma disruption. Our previous results assuming a constant current density (Lenz' Law) model showed that prompt ``hot-tail runaways'' dominated ``knock-on'' and Dreicer ``drizzle'' runaways; we will examine modifications due to the more complete Ampere-Faraday solution. Work supported by US DOE under DE-FG02-ER54744.

Explanation of the photocurrent generation of Cu2O quantum dots (QDs) sensitized p-CuSCN stable photoelectrochemical cells

NASA Astrophysics Data System (ADS)

Karunarathna, P. G. D. C. K.; Samarakoon, S. P. A. U. K.; Fernando, C. A. N.

2018-01-01

Fabrication of Cu2O quantum dots (QDs) sensitized p-CuSCN photoelectrode provides a significant photocurrent enhancement in photoelectrochemical medium for the first time. The variation of photocurrent quantum efficiency (Ф%) with Cu2O amount formed on p-CuSCN was presented. Here, two maxima of photocurrent could be observed in Cu/p-CuSCN/Cu2O photoelectrodes. The first photocurrent peak was due to the Cu2O QDs sensitization on p-CuSCN layer, and the second photocurrent peak was due to the formation of p-n junction. Time development of the photocurrent for Cu/p-CuSCN/n-Cu2O photoelectrodes and material characterization from Fourier transform infrared (FTIR) spectra, scanning electron microscope (SEM) images, energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD) were done in this study in detailed.

The GISS global climate-middle atmosphere model. II - Model variability due to interactions between planetary waves, the mean circulation and gravity wave drag

NASA Technical Reports Server (NTRS)

Rind, D.; Suozzo, R.; Balachandran, N. K.

1988-01-01

The variability which arises in the GISS Global Climate-Middle Atmosphere Model on two time scales is reviewed: interannual standard deviations, derived from the five-year control run, and intraseasonal variability as exemplified by statospheric warnings. The model's extratropical variability for both mean fields and eddy statistics appears reasonable when compared with observations, while the tropical wind variability near the stratopause may be excessive possibly, due to inertial oscillations. Both wave 1 and wave 2 warmings develop, with connections to tropospheric forcing. Variability on both time scales results from a complex set of interactions among planetary waves, the mean circulation, and gravity wave drag. Specific examples of these interactions are presented, which imply that variability in gravity wave forcing and drag may be an important component of the variability of the middle atmosphere.

Optimization of Cost of Building with Concrete Slabs Based on the Maturity Method

NASA Astrophysics Data System (ADS)

Skibicki, Szymon

2017-10-01

The maturity method is a well-known technique for determination of mechanical properties of the concrete (e.g. compressive strength) based on the development of temperature during hardening. The compressive strength of concrete can be used to determine necessary striking time of the formwork. Use of this method for this purpose is economically effective and provides necessary safety measures. This method is used in many construction sites. Time of formwork striking depends on many factors e. g. class of concrete, grade of cement, type of cement, temperature, size of the element and air humidity. The existing technical Standards and scientific research on the striking of formwork present different estimated for the striking time. Striking time for the main structural elements ranges from 14 to 21 days. For structura elements such as slabs or beams with a span of more than 6 m need to reach the minimum of 70-85% of their designed strength to remove the formwork depend on the Standards. During the construction of the buildings in summer concrete acquires the required strength for striking of the formwork faster due to the higher ambient temperature. Knowing the maturity method, we are able to estimate the compressive strength of concrete. If concrete have the required strength, the striking time can be shortened. This allows to reduce the overall costs of construction. The more concrete works are done during the construction phase the bigger the generated savings. In this article formwork striking time for concrete slabs in building based on maturity method was determined. The structure was subjected to 10 different simulated weather conditions typical for the Central and Western Europe that varied by localization of the construction. Based on simulated weather conditions the temperature in structural elements was established. The results allowed to determine the formwork striking time using the maturity method. Presented analysis shows that use of the maturity method on construction site can result in lower overall costs due to shorter time of constructing.

Using GNSS for Assessment Recent Sea Level Rise in the Northwestern Part of the Arabian Gulf

NASA Astrophysics Data System (ADS)

Alothman, A. O.; Bos, M. S.; Fernandes, R.

2017-12-01

Due to the global warming acting recently (in the 21st century) on the planet Earth, an associated sea level rise is predicted to reach up to 30 cm to 60 cm in some regions. Sea level monitoring is important for the Kingdom of Saudi Arabia, since it is surrounded by very long cost of about 3400 km in length and hundreds of isolated islands. The eastern coast line of KSA, in the Arabian Gulf, needs some monitoring in the long term, due to low land nature of the region. Also, the ongoing oil withdrawal activities in the area, may affect the regional sea level rise. In addition to these two facts, the tectonic structure of the Arabian Peninsula is one factor. The Regional Relative sea level in the eastern cost of Saudi Arabia has been estimated in the past using tide gauge data of more than 28 years using the vertical displacement of permanent Global Navigation Satellite System GNSS stations having time span of only about 3 years. In this paper, we discuss and update the methodology and results from Alothman et al. (2014), particularly by checking and extending the GNSS solutions. Since 3 of the 6 GPS stations used only started observing in the end of 2011, the longer time series have now significantly lower uncertainties in the estimated vertical rate. Longer time span of GNSS observations were included and 500 synthetic time series were estimated and seasonal signals were analysed. it is concluded that the varying seasonal signal present in the GNSS time series causes an underestimation of 0.1 mm/yr for short time series of 3 years. In addition to the implications of using short time series to estimate the vertical land motion, we found that if the varying seasonal signals are present in the data, the problem is aggravated. This finding can be useful for other studies analyzing short GNSS time series.

Nuclear Fission Investigation with Twin Ionization Chamber

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

Zeynalova, O.; Zeynalov, Sh.; Nazarenko, M.

2011-11-29

The purpose of the present paper was to report the recent results, obtained in development of digital pulse processing mathematics for prompt fission neutron (PFN) investigation using twin ionization chamber (TIC) along with fast neutron time-of-flight detector (ND). Due to well known ambiguities in literature (see refs. [4, 6, 9 and 11]), concerning a pulse induction on TIC electrodes by FF ionization, we first presented detailed mathematical analysis of fission fragment (FF) signal formation on TIC anode. The analysis was done using Ramo-Shockley theorem, which gives relation between charged particle motion between TIC electrodes and so called weighting potential. Weightingmore » potential was calculated by direct numerical solution of Laplace equation (neglecting space charge) for the TIC geometry and ionization, caused by FF. Formulae for grid inefficiency (GI) correction and digital pulse processing algorithms for PFN time-of-flight measurements and pulse shape analysis are presented and discussed.« less

Investigation on the absolute and relative photoionization cross sections of 3 potential propargylic fuels.

PubMed

Winfough, Matthew; Meloni, Giovanni

2017-12-01

Absolute photoionization cross sections for 2 potential propargylic fuels (propargylamine and dipropargyl ether) along with the partial ionization cross sections for their dissociative fragments are measured and presented for the first time via synchrotron photoionization mass spectrometry. The experimental setup consists of a multiplexed orthogonal time-of-flight mass spectrometer and is located at the Advanced Light Source facility of the Lawrence Berkeley National Laboratory in Berkeley, California. Data for a third propargylic compound (propargyl alcohol) were taken; however, because of its low signal, due to its weakly bound cation, only the dissociative ionization fragment from the H-loss channel is observed and presented. Suggested pathways leading to formation of dissociative photoionization fragments along with CBS-QB3 calculated adiabatic ionization energies and appearance energies for the dissociative fragments are also presented. Copyright © 2017 John Wiley & Sons, Ltd.

Severe Bleeding In a Woman Heterozygous for the Fibrinogen γR275C Mutation

PubMed Central

Rein, Chantelle M.; Anderson, Brian L; Ballard, Morgan M.; Domes, Christopher M.; Johnston, Joshua M.; Madsen, R. Jared; Wolper, Kathryn K. M.; Terker, Andrew S.; Strother, John M.; Deloughery, Thomas G.; Farrell, David H.

2010-01-01

The dysfibrinogen γR275C can be a clinically silent mutation, with only two out of seventeen cases in the literature reporting a hemorrhagic presentation, and four cases reporting a thrombotic presentation. We describe here a particularly severe presentation in 54-year-old female patient who required a hysterectomy at 47 years of age due to heavy menstrual bleeding. Coagulation studies revealed a prolonged prothrombin time and thrombin time, a normal fibrinogen antigen level, and a low fibrinogen activity level. Molecular analysis of the patient’s DNA revealed a γ chain gene mutation resulting in an amino acid substitution at residue 275 (γR275C). Protein sequencing of the fibrinogen γ chain confirmed this mutation, which was named Fibrinogen Portland I. This case demonstrates that the γR275C mutation can lead to a severe hemorrhagic phenotype. PMID:20386430

Improvement of the tissue-adhesive and sealing effect of fibrin sealant using polyglycolic acid felt.

PubMed

Shinya, Noriko; Oka, Shirou; Miyabashira, Sumika; Kaetsu, Hiroshi; Uchida, Takanori; Sueyoshi, Masuo; Takase, Kozo; Akuzawa, Masao; Miyamoto, Atsushi; Shigaki, Takamichi

2009-01-01

Although fibrin sealant (FS) has an advantage of high biocompatibility, its adhesive force and sealing effect have been generally considered to be inadequate. In the present study, a high adhesive force and sealing effect were obtained by first rubbing fibrinogen solution into the target tissue, attaching polyglycolic acid (PGA) felt to the treated area, and finally spraying it with FS. This method was compared with three conventional FS application methods and a method using fibrin glue-coated collagen fleece. The adhesive force resulting from the present method was 12 times higher than that for the sequential application method, 4.5 times higher than the spray method, 2.5 times higher than the rubbing and spray method, and 2.2 times higher than the use of fibrin glue-coated collagen fleece. The high adhesive force of FS with PGA felt seemed to be due the high fibrin content of the fibrin gel (FG). Light and electron microscopic observations suggested that the formation of FG in closer contact with the muscle fibers was a factor contributing to this superior adhesive force. Comparison of the sealing effect of the present method with other methods using various biomaterials in combination with FS showed that the sealing effect of FS with PGA felt was 1.4 times higher that of polyglactin 910, 1.8 times that of polytetrafluoroethylene, and 6.7 times that of oxidized regenerated cellulose.

Maternal mortality following caesarean sections.

PubMed

Sikdar, K; Kundu, S; Mandal, G S

1979-08-01

A study of 26 maternal deaths following 3647 caesarean sections was conducted in Eden Hospital from 1974-1977. During the time period there were 35,544 births and 308 total maternal deaths (8.74/1000). Indications for Caesarean sections included: 1) abnormal presentation; 2) cephalopelvic disproportion; 3) toxemia; 4) prolonged labor; 5) fetal distress; and 6) post-caesarean pregnancies. Highest mortality rates were among cephalopelvic disproportion, toxemia, and prolonged labor patients. 38.4% of the patients died due to septicaemia and peritonitis, but other deaths were due to preclampsia, shock, and hemorrhage. Proper antenatal care may have prevented anemia and preclampsia and treated other pre-existing or superimposed diseases.

[Graft Pseudoaneurysm after Ascending to Abdominal Aorta Bypass for Atypical Coarctation Due to Aortitis Syndrome;Report of a Case].

PubMed

Yada, Masashi; Yamanaka, Kazuo; Miwa, Senri; Hirose, Keiichi; Sakaguchi, Hisashi; Yoshida, Yukiyo; Onga, Youhei; Tara, Yuichi

2017-05-01

We present a case of a 44-year-old woman, with pseudoaneurysm formation at the middle of the prosthetic graft, 60 mm in diameter. She had been diagnosed with atypical coarctation due to aortitis 27 years before, and had undergone a bypass operation with 14 mm-diameter Cooley double velour graft from the ascending aorta to the abdominal aorta. This time, endovascular aortic repair was performed to prevent rupture of the pseudoaneurysm. Though a knitted Dacron graft has a risk of psuedaneurysm formation long patency could be obtained when used in ascending aorta-abdominal aorta bypass.

High-precision surface analysis of the roughness of Michelangelo's David

NASA Astrophysics Data System (ADS)

Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Marras, Luciano; Materazzi, Marzia; Pampaloni, Enrico; Pezzati, Luca

2003-10-01

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to wearing agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo"s David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.

The World Trade Center Attack: Eye witness: observations of a physician on the outside looking in

PubMed Central

Chalfin, Donald B

2001-01-01

Having personally witnessed the destruction at the World Trade Center on 11 September 2001, this paper presents my personal feelings and observations as an observer of both disaster and terror. Aside from the unimaginable horror as a result of the carnage, a feeling of helplessness was particularly prominent due to the inability to be able to care for casualties since most victims were fatalities. The passage of time has enabled a return to normalcy, however 'normalcy' carries a new definition due to the vastness of the tragedy and the sudden threat of bioterrorism and other weapons of mass destruction. PMID:11737914

Non-volatile analysis in fruits by laser resonant ionization spectrometry: application to resveratrol (3,5,4'-trihydroxystilbene) in grapes

NASA Astrophysics Data System (ADS)

Montero, C.; Orea, J. M.; Soledad Muñoz, M.; Lobo, R. F. M.; González Ureña, A.

A laser desorption (LD) coupled with resonance-enhanced multiphoton ionisation (REMPI) and time-of-flight mass spectrometry (TOFMS) technique for non-volatile trace analysis compounds is presented. Essential features are: (a) an enhanced desorption yield due to the mixing of metal powder with the analyte in the sample preparation, (b) a high resolution, great sensitivity and low detection limit due to laser resonant ionisation and mass spectrometry detection. Application to resveratrol content in grapes demonstrated the capability of the analytical method with a sensitivity of 0.2 pg per single laser shot and a detection limit of 5 ppb.

Some chronobiological considerations related to physical exercise.

PubMed

Reilly, T; Atkinson, G; Gregson, W; Drust, B; Forsyth, J; Edwards, B; Waterhouse, J

2006-01-01

Variables associated with physical activity show circadian rhythms in resting subjects; these rhythms have both exogenous (due to the individual's lifestyle and environment) and endogenous (due to the "body clock") components. During exercise, many of the rhythms persist, even though some show decreasing amplitude with increasing severity of exercise. Whilst the value of physical fitness is not disputed (for elite athletes, for individuals who just want to be physically fit, or for patients undertaking physical rehabilitation regimens), there are certain times of the day when special care is needed. These times are soon after waking--when there is the possibility of an increased risk of cardiovascular morbidity and damage to the spine--and late in the day--when there is an increased risk of respiratory difficulties. Since physical exercise is inextricably linked with thermoregulation, there are special considerations to bear in mind when exercise takes place in cold or hot environments. Further, due to the effects of the body clock, exercise and activity during night work and after time-zone transitions presents problems peculiar to these circumstances. In addition, the menstrual cycle affects physical performance, and these circatrigintan rhythms interact with the circadian ones. Bearing in mind these factors, advice that is based upon knowledge of circadian and circatrigintan rhythms can be given to all those contemplating physical activity. Chronobiologically, there is advantage in undertaking physical activity programmes towards the middle of the waking day and not at times when a sleep or nap has just been taken.

Using geographic information systems to evaluate cardiac arrest survival.

PubMed

Warden, Craig R; Daya, Mohamud; LeGrady, Lara A

2007-01-01

To evaluate cardiac arrest survival using geographical information systems (GIS) methodology. Patient data were obtained from a fire district Utstein-style adult cardiac arrest registry that also included address data. All incident locations were geocoded and fire station first-due areas were mapped by using the new computer-aided dispatch geographic data. Retrospective assignment of first-due versus second-due fire response unit was done by using a GIS "point-in-polygon" algorithm Survival to hospital admission was the primary outcome measure for incidents responded to by first-due versus second-due apparatus controlling for other potential predictors of survival using logistic regression. Cluster analysis was also performed to evaluate potential areas of high or low rates of survival. There were 461 eligible patients with an average age of 67+/-17 years, 63% were male, 53% had a witnessed arrest, bystander cardiopulmonary resuscitation was performed in 38%, bystander automatic external defibrillator (AED) Page: 1 was used in 0.01%, ventricular fibrillation or ventricular tachycardia were the presenting rhythms in 44%, the average response time was 5.5+/-2.1 minutes, and survival to hospital admission was 17%. There was no significant difference in response time between survivors (4.97 minutes) and non-survivors (5.52 minutes), (difference 0.55 minutes, 95%CI -0.08 to 1.18 min). The number of cardiac arrest calls varied from 1 to 49 for each station and the rate of second-due response varied from 0 to 19%. There was a nonsignificant association of survival to hospital admission for the first-due area cohort: odds ratio 0.70, 95% CI 0.38-1.29. GIS is a new methodology for analyzing EMS incident data. It adds a spatial component of analysis to traditional statistical techniques. No spatial difference was found on patient survival in this analysis.

Paid expenditures and productivity costs associated with permanent disability pensions in patients with spinal disorders: Nationwide Finnish Register-based Study, 1990-2010.

PubMed

Asklöf, Tom; Martikainen, Janne; Kautiainen, Hannu; Haanpää, Maija; Kiviranta, Ilkka; Pohjolainen, Timo

2016-01-01

The objective of this study is to present the paid expenditures and productivity costs of disability pensions (DP) due to spinal disorders (SD) in Finland during 1990-2010. This study is a register-based national study. All new cases aged 20-64 that were granted a DP due to SD were identified from the nationwide register maintained by the Finnish Centre of Pensions. The data included sex, age group, year of the DP decision, main cause of incapacity (diagnosis) leading to permanent DP and yearly paid expenditures for DPs. Annual productivity costs were estimated based on labour force participation rate and the employment rate adjusted gross domestic product. A total of 39,107 individuals (18,072 females, 21,035 males) received DPs during the study period. SDs generated 9,372 million euros extra cost during this period due to DP (females 3.5 billion, males 5.9 billion). The total DP expenditures paid increased during the first half of 1990s but decreased during the second half of 1990s (-44.8 %). For degenerative SD cases, the DP expenditure was 5.1 billion €, disc disease 3.5 billion € and for other SDs 0.7 billion €. Males, compared to females, were expected to have a rate 1.22 times greater costs due to DPs. The estimated total annual productivity costs due to SDs have been over six times higher than expenditures paid for DPs per year. The costs of DPs are different compared to occurrence rates due to salary and early retirement age differences between genders. Despite a significant decrease in DP-associated expenditures due to SDs after 1993, the annual expenditures have stayed on a high level in Finland.

[External cephalic version in cases of breech presentation: renaissance of a well-known procedure?].

PubMed

Schmidt, M; Callies, R; Kuhn, U; Willruth, A; Kimmig, R

2009-01-01

About 3-4% of all pregnant women will have a fetus presenting by the breech at term. External cephalic version offers the opportunity to reduce the rate of caesarean sections caused by breech presentation. We analysed retrospectively 51 cases of external cephalic version at our clinic. External cephalic version was performed 51 times between 37 and 41 weeks of pregnancy. External cephalic version was successful in 32/51 cases (62,7%) with a consecutive rate of vaginal delivery of 71,9%. The best results were seen at 37 weeks of pregnancy with 81,25% of successful versions followed by 76,9% of vaginal deliveries. Complications were rare. There was just 1 case of emergency caesarean section due to persisting fetal bradycardia. External cephalic version is an effective and safe treatment to enable vaginal delivery of cephalic presentation. For this operation, 37 weeks of pregnancy can be considered the best time. 2009 S. Karger AG, Basel.

A fast passive and planar liquid sample micromixer.

PubMed

Melin, Jessica; Gimenéz, Guillem; Roxhed, Niclas; van der Wijngaart, Wouter; Stemme, Göran

2004-06-01

A novel microdevice for passively mixing liquid samples based on surface tension and a geometrical mixing chamber is presented. Due to the laminar flow regime on the microscale, mixing becomes difficult if not impossible. We present a micromixer where a constantly changing time dependent flow pattern inside a two sample liquid plug is created as the plug simply passes through the planar mixer chamber. The device requires no actuation during mixing and is fabricated using a single etch process. The effective mixing of two coloured liquid samples is demonstrated.

The evolution of Orbiter depot support, with applications to future space vehicles

NASA Technical Reports Server (NTRS)

Mcclain, Michael L.

1990-01-01

The reasons for depot consolidation and the processes established to implement the Orbiter depot are presented. The Space Shuttle Orbiter depot support is presently being consolidated due to equipment suppliers leaving the program, escalating depot support costs, and increasing repair turnaround times. Details of the depot support program for orbiter hardware and selected pieces of support equipment are discussed. The benefits gained from this consolidation and the lessons learned are then applied to future reuseable space vehicles to provide program managers a forward look at the need for efficient depot support.

Nonlinear vibration of an axially loaded beam carrying rigid bodies

NASA Astrophysics Data System (ADS)

Barry, O.

2016-12-01

This paper investigates the nonlinear vibration due to mid-plane stretching of an axially loaded simply supported beam carrying multiple rigid masses. Explicit expressions and closed form solutions of both linear and nonlinear analysis of the present vibration problem are presented for the first time. The validity of the analytical model is demonstrated using finite element analysis and via comparison with the result in the literature. Parametric studies are conducted to examine how the nonlinear frequency and frequency response curve are affected by tension, rotational inertia, and number of intermediate rigid bodies.

Transient snakes in an ohmic plasma associated with a minor disruption in the HT-7 tokamak

NASA Astrophysics Data System (ADS)

Mao, Songtao; Xu, Liqing; Hu, Liqun; Chen, Kaiyun

2014-05-01

A transient burst (ms, an order of the fast-particle slowdown timescale) of a spontaneous snake is observed for the first time in a HT-7 heavy impurity ohmic plasma. The features of the low-Z impurity snake are presented. The flatten electron profile due to the heavy impurity reveals the formation of a large magnetic island. The foot of the impurity accumulation is consistent with the location of the transient snake. The strong frequency-chirping behaviors and the spatial structures of the snake are also presented.

Refinements in the Los Alamos model of the prompt fission neutron spectrum

DOE PAGES

Madland, D. G.; Kahler, A. C.

2017-01-01

This paper presents a number of refinements to the original Los Alamos model of the prompt fission neutron spectrum and average prompt neutron multiplicity as derived in 1982. The four refinements are due to new measurements of the spectrum and related fission observables many of which were not available in 1982. Here, they are also due to a number of detailed studies and comparisons of the model with previous and present experimental results including not only the differential spectrum, but also integal cross sections measured in the field of the differential spectrum. The four refinements are (a) separate neutron contributionsmore » in binary fission, (b) departure from statistical equilibrium at scission, (c) fission-fragment nuclear level-density models, and (d) center-of-mass anisotropy. With these refinements, for the first time, good agreement has been obtained for both differential and integral measurements using the same Los Alamos model spectrum.« less

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

Madland, D. G.; Kahler, A. C.

This paper presents a number of refinements to the original Los Alamos model of the prompt fission neutron spectrum and average prompt neutron multiplicity as derived in 1982. The four refinements are due to new measurements of the spectrum and related fission observables many of which were not available in 1982. Here, they are also due to a number of detailed studies and comparisons of the model with previous and present experimental results including not only the differential spectrum, but also integal cross sections measured in the field of the differential spectrum. The four refinements are (a) separate neutron contributionsmore » in binary fission, (b) departure from statistical equilibrium at scission, (c) fission-fragment nuclear level-density models, and (d) center-of-mass anisotropy. With these refinements, for the first time, good agreement has been obtained for both differential and integral measurements using the same Los Alamos model spectrum.« less

Green's functions for analysis of dynamic response of wheel/rail to vertical excitation

NASA Astrophysics Data System (ADS)

Mazilu, Traian

2007-09-01

An analytical model to simulate wheel/rail interaction using the Green's functions method is proposed in this paper. The model consists of a moving wheel on a discretely supported rail. Particularly for this model of rail, the bending and the longitudinal displacement are coupled due to the rail pad and a complex model of the rail pad is adopted. An efficient method for solving a time-domain analysis for wheel/rail interaction is presented. The method is based on the properties of the rail's Green functions and starting to these functions, a track's Green matrix is assembled for the numerical simulations of wheel/rail response due to three kinds of vertical excitations: the steady-state interaction, the rail corrugation and the wheel flat. The study points to influence of the worn rail—rigid contact—on variation in the wheel/rail contact force. The concept of pinned-pinned inhibitive rail pad is also presented.

Role of Equatorial Anomaly in Earthquake time precursive features: A few strong events over West Pacific zone

NASA Astrophysics Data System (ADS)

Devi, Minakshi; Patgiri, S.; Barbara, A. K.; Oyama, Koh-Ichiro; Ryu, K.; Depuev, V.; Depueva, A.

2018-03-01

The earthquake (EQ) time coupling processes between equator-low-mid latitude ionosphere are complex due to inherent dynamical status of each latitudinal zone and qualified geomagnetic roles working in the system. In an attempt to identify such process, the paper presents temporal and latitudinal variations of ionization density (foF2) covering 45°N to 35°S, during a number of earthquake events (M > 5.5). The approaches adopted for extraction of features by the earthquake induced preparatory processes are discussed in the paper through identification of parameters like the 'EQ time modification in density gradient' defined by δ = (foF2 max - foF2 min)/τmm, where τmm - time span (in days) between EQ modified density maximum and minimum, and the Earthquake time Equatorial Anomaly, i.e. EEA, one of the most significant phenomenon which develops even during night time irrespective of epicenter position. Based on the observations, the paper presents the seismic time coupling dynamics through anomaly like manifestations between equator, low and mid latitude ionosphere bringing in the global Total Electron Content (TEC) features as supporting indices.

Cold starting of fluorescent lamps - part II: experiments on glow times and electrode damaging

NASA Astrophysics Data System (ADS)

Langer, Reinhard; Paul, Irina; Hilscher, Achim; Horn, Siegfried; Tidecks, Reinhard

2017-01-01

In the present work we present experiments on cold start and the resulting electrode damaging (reducing lamp life) of AC driven fluorescent lamps. The crucial parameter is the glow time, determined from time resolved measurements of lamp voltage and current. The relation between the energy consumed during glow phase and the glow time is studied. It turns out that there is no common threshold of energy until the glow-to-arc transition takes place, but strong energy input into the lamp yields short glow times. The transient behaviour from the glow to the arc regime is investigated and the stable operation points of the arc discharge are determined, yielding an arc discharge voltage-current characteristics of the lamp type investigated. The electrode damage is investigated as a function of the open source voltage and the ballast resistance. Subsequent cold starts lead to an increase of the glow time due to electrode damaging, i.e., the electrode damage accumulates. Different regeneration procedures and their effectiveness are compared. Regeneration burning turns out to be more effective than heating up the electrode. A criterion for avoiding high electrode damage is obtained, indicating that the average power during glow time should exceed 20 W.

Branchial cleft cyst encircling the hypoglossal nerve

PubMed Central

Long, Kristin L.; Spears, Carol; Kenady, Daniel E.

2013-01-01

Branchial cleft anomalies are a common cause of lateral neck masses and may present with infection, cyst enlargement or fistulas. They may affect any of the nearby neck structures, causing compressive symptoms or vessel thrombosis. We present a case of a branchial cleft cyst in a 10-year-old boy who had been present for 1year. At the time of operation, the cyst was found to completely envelop the hypoglossal nerve. While reports of hypoglossal nerve palsies due to external compression from cysts are known, we believe this to be the first report of direct nerve involvement by a branchial cleft cyst. PMID:24963902

NASA Automated Rendezvous and Capture Review. A compilation of the abstracts

NASA Technical Reports Server (NTRS)

1991-01-01

This document presents a compilation of abstracts of papers solicited for presentation at the NASA Automated Rendezvous and Capture Review held in Williamsburg, VA on November 19-21, 1991. Due to limitations on time and other considerations, not all abstracts could be presented during the review. The organizing committee determined however, that all abstracts merited availability to all participants and represented data and information reflecting state-of-the-art of this technology which should be captured in one document for future use and reference. The organizing committee appreciates the interest shown in the review and the response by the authors in submitting these abstracts.

Effect of centrifugation time on growth factor and MMP release of an experimental platelet-rich fibrin-type product.

PubMed

Eren, Gülnihal; Gürkan, Ali; Atmaca, Harika; Dönmez, Ayhan; Atilla, Gül

2016-07-01

Platelet-rich fibrin (PRF) has a controlled release of growth factors due to the fibrin matrix structure. Different centrifugation protocols were suggested for PRF preparation. Since the derivation method of PRF can alter its contents, in the present study it is aimed to investigate the cell contents and transforming growth factor beta-1 (TGF-β1), platelet-derived growth factor (PDGF-AB), vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-1 and-8 release from experimental PRF-type membranes obtained with different centrifugation times at 400 gravity. Three blood samples were collected from 20 healthy non-smoker volunteers. One tube was used for whole blood analyses. The other two tubes were centrifuged at 400 g for 10 minutes (group A) or 12 minutes (group B). Each experimental PRF-type membrane was placed in Dulbecco's Modified Eagle's Medium (DMEM)and at 1, 24 and 72 hours, TGF-β1, PDGF-AB, VEGF, MMP-1 and -8 release amounts were analysed by enzyme-linked immunosorbent assay (ELISA). The blood cell count of membranes was determined by subtracting plasma supernatant and red blood cell (RBC) mixture from the whole blood cell counts. At 72 hours, the VEGF level of group B was statistically higher than that of group A (p = 0.040). The centrifugation time was not found to influence the release of other growth factors, enzymes and cell counts. Within the limits of the present study, it might be suggested that centrifugation time at a constant gravity has a significant effect on the VEGF levels released from experimental PRF-type membrane. It can be concluded that due to the importance of VEGF in the tissue healing process, membranes obtained at 12-minute centrifugation time may show a superior potential in wound healing.

Empirical models for fitting of oral concentration time curves with and without an intravenous reference.

PubMed

Weiss, Michael

2017-06-01

Appropriate model selection is important in fitting oral concentration-time data due to the complex character of the absorption process. When IV reference data are available, the problem is the selection of an empirical input function (absorption model). In the present examples a weighted sum of inverse Gaussian density functions (IG) was found most useful. It is shown that alternative models (gamma and Weibull density) are only valid if the input function is log-concave. Furthermore, it is demonstrated for the first time that the sum of IGs model can be also applied to fit oral data directly (without IV data). In the present examples, a weighted sum of two or three IGs was sufficient. From the parameters of this function, the model-independent measures AUC and mean residence time can be calculated. It turned out that a good fit of the data in the terminal phase is essential to avoid parameter biased estimates. The time course of fractional elimination rate and the concept of log-concavity have proved as useful tools in model selection.

Next-generation digital camera integration and software development issues

NASA Astrophysics Data System (ADS)

Venkataraman, Shyam; Peters, Ken; Hecht, Richard

1998-04-01

This paper investigates the complexities associated with the development of next generation digital cameras due to requirements in connectivity and interoperability. Each successive generation of digital camera improves drastically in cost, performance, resolution, image quality and interoperability features. This is being accomplished by advancements in a number of areas: research, silicon, standards, etc. As the capabilities of these cameras increase, so do the requirements for both hardware and software. Today, there are two single chip camera solutions in the market including the Motorola MPC 823 and LSI DCAM- 101. Real time constraints for a digital camera may be defined by the maximum time allowable between capture of images. Constraints in the design of an embedded digital camera include processor architecture, memory, processing speed and the real-time operating systems. This paper will present the LSI DCAM-101, a single-chip digital camera solution. It will present an overview of the architecture and the challenges in hardware and software for supporting streaming video in such a complex device. Issues presented include the development of the data flow software architecture, testing and integration on this complex silicon device. The strategy for optimizing performance on the architecture will also be presented.

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

Radhi, Hassan

Developments in the design and manufacture of photovoltaic cells have recently been a growing concern in the UAE. At present, the embodied energy pay-back time (EPBT) is the criterion used for comparing the viability of such technology against other forms. However, the impact of PV technology on the thermal performance of buildings is not considered at the time of EPBT estimation. If additional energy savings gained over the PV system life are also included, the total EPBT could be shorter. This paper explores the variation of the total energy of building integrated photovoltaic systems (BiPV) as a wall cladding systemmore » applied to the UAE commercial sector and shows that the ratio between PV output and saving in energy due to PV panels is within the range of 1:3-1:4. The result indicates that for the southern and western facades in the UAE, the embodied energy pay-back time for photovoltaic system is within the range of 12-13 years. When reductions in operational energy are considered, the pay-back time is reduced to 3.0-3.2 years. This study comes to the conclusion that the reduction in operational energy due to PV panels represents an important factor in the estimation of EPBT. (author)« less

Postmortem ICD interrogation in mode of death classification.

PubMed

Nikolaidou, Theodora; Johnson, Miriam J; Ghosh, Justin M; Marincowitz, Carl; Shah, Saumil; Lammiman, Michael J; Schilling, Richard J; Clark, Andrew L

2018-04-01

The definition of sudden death due to arrhythmia relies on the time interval between onset of symptoms and death. However, not all sudden deaths are due to arrhythmia. In patients with an implantable cardioverter defibrillator (ICD), postmortem device interrogation may help better distinguish the mode of death compared to a time-based definition alone. This study aims to assess the proportion of "sudden" cardiac deaths in patients with an ICD that have confirmed arrhythmia. We conducted a literature search for studies using postmortem ICD interrogation and a time-based classification of the mode of death. A modified QUADAS-2 checklist was used to assess risk of bias in individual studies. Outcome data were pooled where sufficient data were available. Our search identified 22 studies undertaken between 1982 and 2015 with 23,600 participants. The pooled results (excluding studies with high risk of bias) suggest that ventricular arrhythmias are present at the time of death in 76% of "sudden" deaths (95% confidence interval [CI] 67-85; range 42-88). Postmortem ICD interrogation identifies 24% of "sudden" deaths to be nonarrhythmic. Postmortem device interrogation should be considered in all cases of unexplained sudden cardiac death. © 2018 Wiley Periodicals, Inc.

Nonequilibrium statistical mechanics Brussels-Austin style

NASA Astrophysics Data System (ADS)

Bishop, Robert C.

The fundamental problem on which Ilya Prigogine and the Brussels-Austin Group have focused can be stated briefly as follows. Our observations indicate that there is an arrow of time in our experience of the world (e.g., decay of unstable radioactive atoms like uranium, or the mixing of cream in coffee). Most of the fundamental equations of physics are time reversible, however, presenting an apparent conflict between our theoretical descriptions and experimental observations. Many have thought that the observed arrow of time was either an artifact of our observations or due to very special initial conditions. An alternative approach, followed by the Brussels-Austin Group, is to consider the observed direction of time to be a basic physical phenomenon due to the dynamics of physical systems. This essay focuses mainly on recent developments in the Brussels-Austin Group after the mid-1980s. The fundamental concerns are the same as in their earlier approaches (subdynamics, similarity transformations), but the contemporary approach utilizes rigged Hilbert space (whereas the older approaches used Hilbert space). While the emphasis on nonequilibrium statistical mechanics remains the same, their more recent approach addresses the physical features of large Poincaré systems, nonlinear dynamics and the mathematical tools necessary to analyze them.

Comparative study on novel test systems to determine disintegration time of orodispersible films.

PubMed

Preis, Maren; Gronkowsky, Dorothee; Grytzan, Dominik; Breitkreutz, Jörg

2014-08-01

Orodispersible films (ODFs) are a promising innovative dosage form enabling drug administration without the need for water and minimizing danger of aspiration due to their fast disintegration in small amounts of liquid. This study focuses on the development of a disintegration test system for ODFs. Two systems were developed and investigated: one provides an electronic end-point, and the other shows a transferable setup of the existing disintegration tester for orodispersible tablets. Different ODF preparations were investigated to determine the suitability of the disintegration test systems. The use of different test media and the impact of different storage conditions of ODFs on their disintegration time were additionally investigated. The experiments showed acceptable reproducibility (low deviations within sample replicates due to a clear determination of the measurement end-point). High temperatures and high humidity affected some of the investigated ODFs, resulting in higher disintegration time or even no disintegration within the tested time period. The methods provided clear end-point detection and were applicable for different types of ODFs. By the modification of a conventional test system to enable application for films, a standard method could be presented to ensure uniformity in current quality control settings. © 2014 Royal Pharmaceutical Society.

Evaluating sedimentation problems in activated sludge treatment plants operating at complete sludge retention time.

PubMed

Amanatidou, Elisavet; Samiotis, Georgios; Trikoilidou, Eleni; Pekridis, George; Taousanidis, Nikolaos

2015-02-01

Zero net sludge growth can be achieved by complete retention of solids in activated sludge wastewater treatment, especially in high strength and biodegradable wastewaters. When increasing the solids retention time, MLSS and MLVSS concentrations reach a plateau phase and observed growth yields values tend to zero (Yobs ≈ 0). In this work, in order to evaluate sedimentation problems arised due to high MLSS concentrations and complete sludge retention operational conditions, two identical innovative slaughterhouse wastewater treatment plants were studied. Measurements of wastewaters' quality characteristics, treatment plant's operational conditions, sludge microscopic analysis and state point analysis were conducted. Results have shown that low COD/Nitrogen ratios increase sludge bulking and flotation phenomena due to accidental denitrification in clarifiers. High return activated sludge rate is essential in complete retention systems as it reduces sludge condensation and hydraulic retention time in the clarifiers. Under certain operational conditions sludge loading rates can greatly exceed literature limit values. The presented methodology is a useful tool for estimation of sedimentation problems encountered in activated sludge wastewater treatment plants with complete retention time. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Low Energy Neutrino Spectrometry (LENS) Experiment and LENS prototype, μLENS, initial results

NASA Astrophysics Data System (ADS)

Yokley, Zachary

2012-03-01

LENS is a low energy solar neutrino detector that will measure the solar neutrino spectrum above 115 keV, >95% of the solar neutrino flux, in real time. The fundamental neutrino reaction in LENS is charged-current based capture on 115-In detected in a liquid scintillator medium. The reaction yields the prompt emission of an electron and the delayed emission of 2 gamma rays that serve as a time & space coincidence tag. Sufficient spatial resolution is used to exploit this signature and suppress background, particularly due to 115-In beta decay. A novel design of optical segmentation (Scintillation Lattice or SL) channels the signal light along the three primary axes. The channeling is achieved via total internal reflection by suitable low index gaps in the segmentation. The spatial resolution of a nuclear event is obtained digitally, much more precisely than possible by common time of flight methods. Advanced Geant4 analysis methods have been developed to suppress adequately the severe background due to 115-In beta decay, achieving at the same time high detection efficiency. LENS physics and detection methods along with initial results characterizing light transport in the as built μLENS prototype will be presented.

Random Time Identity Based Firewall In Mobile Ad hoc Networks

NASA Astrophysics Data System (ADS)

Suman, Patel, R. B.; Singh, Parvinder

2010-11-01

A mobile ad hoc network (MANET) is a self-organizing network of mobile routers and associated hosts connected by wireless links. MANETs are highly flexible and adaptable but at the same time are highly prone to security risks due to the open medium, dynamically changing network topology, cooperative algorithms, and lack of centralized control. Firewall is an effective means of protecting a local network from network-based security threats and forms a key component in MANET security architecture. This paper presents a review of firewall implementation techniques in MANETs and their relative merits and demerits. A new approach is proposed to select MANET nodes at random for firewall implementation. This approach randomly select a new node as firewall after fixed time and based on critical value of certain parameters like power backup. This approach effectively balances power and resource utilization of entire MANET because responsibility of implementing firewall is equally shared among all the nodes. At the same time it ensures improved security for MANETs from outside attacks as intruder will not be able to find out the entry point in MANET due to the random selection of nodes for firewall implementation.

Thermospheric O/N2 in the Sunlit Disk From More Than Five Years of GUVI/TIMED Observations

NASA Astrophysics Data System (ADS)

Craven, J. D.; Christensen, A. B.; Paxton, L. J.

2007-12-01

GUVI indirect observations of the thermospheric column density ratio, O/N2, in the sunlit hemisphere have been made on a nearly continuous basis from day 50 of 2002 to the present as part of the TIMED spacecraft mission. The basic large-scale spatial structure includes variations with local time (greater values in the morning), Universal Time (modulation at high latitudes due to the offset magnetic dipole), and season (greater values in the local winter hemisphere). These differences are seen to fade in the approach to solar minimum. Superposed on this reasonably well-behaved background structure are the complex, transient perturbations driven by auroral substorms and geomagnetic storms. The spatial and temporal variations are summarized in part by time-lapse movies

Cryptographic robustness of a quantum cryptography system using phase-time coding

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

Molotkov, S. N.

2008-01-15

A cryptographic analysis is presented of a new quantum key distribution protocol using phase-time coding. An upper bound is obtained for the error rate that guarantees secure key distribution. It is shown that the maximum tolerable error rate for this protocol depends on the counting rate in the control time slot. When no counts are detected in the control time slot, the protocol guarantees secure key distribution if the bit error rate in the sifted key does not exceed 50%. This protocol partially discriminates between errors due to system defects (e.g., imbalance of a fiber-optic interferometer) and eavesdropping. In themore » absence of eavesdropping, the counts detected in the control time slot are not caused by interferometer imbalance, which reduces the requirements for interferometer stability.« less

Time Evolving Fission Chain Theory and Fast Neutron and Gamma-Ray Counting Distributions

DOE PAGES

Kim, K. S.; Nakae, L. F.; Prasad, M. K.; ...

2015-11-01

Here, we solve a simple theoretical model of time evolving fission chains due to Feynman that generalizes and asymptotically approaches the point model theory. The point model theory has been used to analyze thermal neutron counting data. This extension of the theory underlies fast counting data for both neutrons and gamma rays from metal systems. Fast neutron and gamma-ray counting is now possible using liquid scintillator arrays with nanosecond time resolution. For individual fission chains, the differential equations describing three correlated probability distributions are solved: the time-dependent internal neutron population, accumulation of fissions in time, and accumulation of leaked neutronsmore » in time. Explicit analytic formulas are given for correlated moments of the time evolving chain populations. The equations for random time gate fast neutron and gamma-ray counting distributions, due to randomly initiated chains, are presented. Correlated moment equations are given for both random time gate and triggered time gate counting. There are explicit formulas for all correlated moments are given up to triple order, for all combinations of correlated fast neutrons and gamma rays. The nonlinear differential equations for probabilities for time dependent fission chain populations have a remarkably simple Monte Carlo realization. A Monte Carlo code was developed for this theory and is shown to statistically realize the solutions to the fission chain theory probability distributions. Combined with random initiation of chains and detection of external quanta, the Monte Carlo code generates time tagged data for neutron and gamma-ray counting and from these data the counting distributions.« less

Microscale Characterization of the Viscoelastic Properties of Hydrogel Biomaterials using Dual-Mode Ultrasound Elastography

PubMed Central

Hong, Xiaowei; Stegemann, Jan P.; Deng, Cheri X.

2016-01-01

Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger’s viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. PMID:26928595

Microscale characterization of the viscoelastic properties of hydrogel biomaterials using dual-mode ultrasound elastography.

PubMed

Hong, Xiaowei; Stegemann, Jan P; Deng, Cheri X

2016-05-01

Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger's viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ar 3p photoelectron sideband spectra in two-color XUV + NIR laser fields

NASA Astrophysics Data System (ADS)

Minemoto, Shinichirou; Shimada, Hiroyuki; Komatsu, Kazma; Komatsubara, Wataru; Majima, Takuya; Mizuno, Tomoya; Owada, Shigeki; Sakai, Hirofumi; Togashi, Tadashi; Yoshida, Shintaro; Yabashi, Makina; Yagishita, Akira

2018-04-01

We performed photoelectron spectroscopy using femtosecond XUV pulses from a free-electron laser and femtosecond near-infrared pulses from a synchronized laser, and succeeded in measuring Ar 3p photoelectron sideband spectra due to the two-color above-threshold ionization. In our calculations of the first-order time-dependent perturbation theoretical model based on the strong field approximation, the photoelectron sideband spectra and their angular distributions are well reproduced by considering the timing jitter between the XUV and the NIR pulses, showing that the timing jitter in our experiments was distributed over the width of {1.0}+0.4-0.2 ps. The present approach can be used as a method to evaluate the timing jitter inevitable in FEL experiments.

Aerial Refueling Process Rescheduling Under Job Related Disruptions

NASA Technical Reports Server (NTRS)

Kaplan, Sezgin; Rabadi, Ghaith

2011-01-01

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for each fighter aircraft (job) on the multiple tankers (machines) to minimize the total weighted tardiness. ARSP assumes that the jobs have different release times and due dates. The ARSP is dynamic environment and unexpected events may occur. In this paper, rescheduling in the aerial refueling process with a time set of jobs will be studied to deal with job related disruptions such as the arrival of new jobs, the departure of an existing job, high deviations in the release times and changes in job priorities. In order to keep the stability and to avoid excessive computation, partial schedule repair algorithm is developed and its preliminary results are presented.

Numerical investigation of field enhancement by metal nano-particles using a hybrid FDTD-PSTD algorithm.

PubMed

Pernice, W H; Payne, F P; Gallagher, D F

2007-09-03

We present a novel numerical scheme for the simulation of the field enhancement by metal nano-particles in the time domain. The algorithm is based on a combination of the finite-difference time-domain method and the pseudo-spectral time-domain method for dispersive materials. The hybrid solver leads to an efficient subgridding algorithm that does not suffer from spurious field spikes as do FDTD schemes. Simulation of the field enhancement by gold particles shows the expected exponential field profile. The enhancement factors are computed for single particles and particle arrays. Due to the geometry conforming mesh the algorithm is stable for long integration times and thus suitable for the simulation of resonance phenomena in coupled nano-particle structures.

Summary of 2006 to 2010 FPMU Measurements of International Space Station Frame Potential Variations

NASA Technical Reports Server (NTRS)

Minow, Joseph I.; Wright, Kenneth H., Jr.; Chandler, Michael O.; Coffey, Victoria N.; Craven, Paul D.; Schneider, Todd A.; Parker, Linda N.; Ferguson, Dale C.; Koontz, Steve L.; Alred, John W.

2010-01-01

Electric potential variations on the International Space Station (ISS) structure in low Earth orbit are dominated by contributions from interactions of the United States (US) 160 volt solar arrays with the relatively high density, low temperature plasma environment and inductive potentials generated by motion of the large vehicle across the Earth?s magnetic field. The Floating Potential Measurement Unit (FPMU) instrument suite comprising two Langmuir probes, a plasma impedance probe, and a floating potential probe was deployed in August 2006 for use in characterizing variations in ISS potential, the state of the ionosphere along the ISS orbit and its effect on ISS charging, evaluating effects of payloads and visiting vehicles, and for supporting ISS plasma hazard assessments. This presentation summarizes observations of ISS frame potential variations obtained from the FPMU from deployment in 2006 through the current time. We first describe ISS potential variations due to current collection by solar arrays in the day time sector of the orbit including eclipse exit and entry charging events, potential variations due to plasma environment variations in the equatorial anomaly, and visiting vehicles docked to the ISS structure. Next, we discuss potential variations due to inductive electric fields generated by motion of the vehicle across the geomagnetic field and the effects of external electric fields in the ionosphere. Examples of night time potential variations at high latitudes and their possible relationship to auroral charging are described and, finally, we demonstrate effects on the ISS potential due to European Space Agency and US plasma contactor devices.

A PEMFC hybrid electric vehicle real time control system

NASA Astrophysics Data System (ADS)

Sun, Hongqiao

In recent years, environmental friendly technologies and alternative energy solutions have drawn a lot of public attentions due to global energy crisis and pollution issues. Fuel cell (FC), a technology invented almost at the same time as the internal combustion (IC) engine, is now the focus of the automotive industry again. The fuel cell vehicle (FCV) has zero emission and its efficiency is significantly higher than the conventional IC engine power vehicles. Among a variety of FCV technologies, proton exchange membrane (PEM) FC vehicle appears to be far more attractive and mature. The prototype PEMFC vehicle has been developed and demonstrated to the public by nearly all the major automotive manufacturers in recent years. However, to the interest of the public research, publications and documentations on the PEMFC vehicle technology are rarely available due to its proprietary nature, which essentially makes it a secured technology. This dissertation demonstrates a real world application of a PEMFC hybrid electric vehicle. Through presenting the vehicle design concept, developing the real time control system and generating generic operation principles, this dissertation targets at establishing the public knowledge base on this new technology. A complete PEMFC hybrid electric vehicle design, including vehicle components layout, process flow diagram, real time control system architecture, subsystem structures and control algorithms, is presented in order to help understand the whole vehicle system. The design concept is validated through the vehicle demonstration. Generic operating principles are established along with the validation process, which helps populate this emerging technology. Thereafter, further improvements and future research directions are discussed.

Evaluating the Reverse Time Migration Method on the dense Lapnet / Polenet seismic array in Europe

NASA Astrophysics Data System (ADS)

Dupont, Aurélien; Le Pichon, Alexis

2013-04-01

In this study, results are obtained using the reverse time migration method used as benchmark to evaluate the implemented method by Walker et al., (2010, 2011). Explosion signals recorded by the USArray and extracted from the TAIRED catalogue (TA Infrasound Reference Event Database user community / Vernon et al., 2012) are investigated. The first one is an explosion at Camp Minden, Louisiana (2012-10-16 04:25:00 UTC) and the second one is a natural gas explosion near Price, Utah (2012-11-20 15:20:00 UTC). We compare our results to automatic solutions (www.iris.edu/spud/infrasoundevent). The good agreement between both solutions validates our detection method. In a second time, we analyse data from the Lapnet / Polenet dense seismic network (Kozlovskaya et al., 2008). Detection and location in two-dimensional space and time of infrasound events presumably due to acoustic-to-seismic coupling, during the 2007-2009 period in Europe, are presented. The aim of this work is to integrate near-real time network performance predictions at regional scales to improve automatic detection of infrasonic sources. The use of dense seismic networks provides a valuable tool to monitor infrasonic phenomena, since seismic location has recently proved to be more accurate than infrasound locations due to the large number of seismic sensors.

Rapid protein concentration, efficient fluorescence labeling and purification on a micro/nanofluidics chip.

PubMed

Wang, Chen; Ouyang, Jun; Ye, De-Kai; Xu, Jing-Juan; Chen, Hong-Yuan; Xia, Xing-Hua

2012-08-07

Fluorescence analysis has proved to be a powerful detection technique for achieving single molecule analysis. However, it usually requires the labeling of targets with bright fluorescent tags since most chemicals and biomolecules lack fluorescence. Conventional fluorescence labeling methods require a considerable quantity of biomolecule samples, long reaction times and extensive chromatographic purification procedures. Herein, a micro/nanofluidics device integrating a nanochannel in a microfluidics chip has been designed and fabricated, which achieves rapid protein concentration, fluorescence labeling, and efficient purification of product in a miniaturized and continuous manner. As a demonstration, labeling of the proteins bovine serum albumin (BSA) and IgG with fluorescein isothiocyanate (FITC) is presented. Compared to conventional methods, the present micro/nanofluidics device performs about 10(4)-10(6) times faster BSA labeling with 1.6 times higher yields due to the efficient nanoconfinement effect, improved mass, and heat transfer in the chip device. The results demonstrate that the present micro/nanofluidics device promises rapid and facile fluorescence labeling of small amount of reagents such as proteins, nucleic acids and other biomolecules with high efficiency.

Anxiolytic and Anticonvulsant Effects on Mice of Flavonoids, Linalool, and α-Tocopherol Presents in the Extract of Leaves of Cissus sicyoides L. (Vitaceae)

PubMed Central

de Almeida, Edvaldo Rodrigues; de Oliveira Rafael, Krissia Rayane; Couto, Geraldo Bosco Lindoso; Ishigami, Ana Beatriz Matos

2009-01-01

The aim of the present study is to demonstrate the anxiolytic and anticonvulsant effects of a hydroalcoholic extract obtained from the aerial parts of Cissus sicyoides L. (CS) (Vitaceae) on male and female mice using several behavioral assays. Groups of males and females treated via intraperitoneal (IP) with doses of 300, 600, and 1000 mg/kg of the extract showed significant action in the elevated plus-maze (EPM), time spent in the open arms, and number of entries in the open arms. The board-hole test also showed a significant increase in the time spent in head-dipping and in marble-burying test of the number of marbles buried. The same treatment increased the duration of sleeping time induced by sodium pentobarbital and also showed a significant increase in protection against pentylenotetrazole-induced convulsions. These results indicate an anxiolytic and anticonvulsant-like action from C. sicyoides L. extract on mice, probably due to the action of flavonoid(s), Linalool, and α-tocopherol present in the C. sicyoides leaves. PMID:19300520

Mahan polaritons and their lifetime due to hole recoil

NASA Astrophysics Data System (ADS)

Baeten, Maarten; Wouters, Michiel

2015-11-01

We present a theoretical study on polaritons in doped semiconductor microcavities, focussing on a cavity mode that is resonant with the Fermi edge. In agreement with experimental results, the strong light-matter coupling is maintained under very high doping within our ladder diagram approximation. In particular, we find that the polaritons result from the strong admixing of the cavity mode with the Mahan exciton. The upper Mahan polariton, lying in the electron-hole continuum, always remains visible and has a linewidth due to free interband electron-hole creation. The lower Mahan polariton acquires a finite lifetime due to relaxation of the valence band hole if the electron density exceeds a certain critical value. However, if the Rabi splitting exceeds the inverse hole recoil time, the lower polariton lifetime is only limited by the cavity properties.

Risk of complications in coeliac patients depends on age at diagnosis and type of clinical presentation.

PubMed

Biagi, Federico; Schiepatti, Annalisa; Maiorano, Gregorio; Fraternale, Giacomo; Agazzi, Simona; Zingone, Fabiana; Ciacci, Carolina; Volta, Umberto; Caio, Giacomo; Tortora, Raffaella; Klersy, Catherine; Corazza, Gino R

2018-06-01

Coeliac disease is characterised by an increased mortality mostly due to its complications. To study the risk of developing complications according to clinical presentation and age at diagnosis, a combined retrospective-prospective longitudinal study was performed in three Italian centres. Incidence of complications and mortality rates were calculated using type and age at diagnosis of coeliac disease, sex, and centre of diagnosis as predictors. Patients referred after being found to suffer from coeliac disease elsewhere were excluded. Between 01/1999 and 06/2015, 2225 adult coeliac patients were directly diagnosed in our centres. 17 of them developed a complication and 29 died. In patients older than 60 years at diagnosis of coeliac disease, the risk of complication is 18 times higher than in patients diagnosed at 18-40 years and 9 times higher than in patients diagnosed at 40-60 years. Classical presentation increases the risk of complications by 7 times compared to non-classical presentation; in asymptomatic patients the risk of complication is virtually absent. The risk of developing complications in coeliac patients is linked to age at diagnosis of coeliac disease and type of clinical presentation. Follow-up methods of coeliac patients should be tailored according to these parameters. Copyright © 2017. Published by Elsevier Ltd.

Methodology for Analysis, Modeling and Simulation of Airport Gate-waiting Delays

NASA Astrophysics Data System (ADS)

Wang, Jianfeng

This dissertation presents methodologies to estimate gate-waiting delays from historical data, to identify gate-waiting-delay functional causes in major U.S. airports, and to evaluate the impact of gate operation disruptions and mitigation strategies on gate-waiting delay. Airport gates are a resource of congestion in the air transportation system. When an arriving flight cannot pull into its gate, the delay it experiences is called gate-waiting delay. Some possible reasons for gate-waiting delay are: the gate is occupied, gate staff or equipment is unavailable, the weather prevents the use of the gate (e.g. lightning), or the airline has a preferred gate assignment. Gate-waiting delays potentially stay with the aircraft throughout the day (unless they are absorbed), adding costs to passengers and the airlines. As the volume of flights increases, ensuring that airport gates do not become a choke point of the system is critical. The first part of the dissertation presents a methodology for estimating gate-waiting delays based on historical, publicly available sources. Analysis of gate-waiting delays at major U.S. airports in the summer of 2007 identifies the following. (i) Gate-waiting delay is not a significant problem on majority of days; however, the worst delay days (e.g. 4% of the days at LGA) are extreme outliers. (ii) The Atlanta International Airport (ATL), the John F. Kennedy International Airport (JFK), the Dallas/Fort Worth International Airport (DFW) and the Philadelphia International Airport (PHL) experience the highest gate-waiting delays among major U.S. airports. (iii) There is a significant gate-waiting-delay difference between airlines due to a disproportional gate allocation. (iv) Gate-waiting delay is sensitive to time of a day and schedule peaks. According to basic principles of queueing theory, gate-waiting delay can be attributed to over-scheduling, higher-than-scheduled arrival rate, longer-than-scheduled gate-occupancy time, and reduced gate availability. Analysis of the worst days at six major airports in the summer of 2007 indicates that major gate-waiting delays are primarily due to operational disruptions---specifically, extended gate occupancy time, reduced gate availability and higher-than-scheduled arrival rate (usually due to arrival delay). Major gate-waiting delays are not a result of over-scheduling. The second part of this dissertation presents a simulation model to evaluate the impact of gate operational disruptions and gate-waiting-delay mitigation strategies, including building new gates, implementing common gates, using overnight off-gate parking and adopting self-docking gates. Simulation results show the following effects of disruptions: (i) The impact of arrival delay in a time window (e.g. 7 pm to 9 pm) on gate-waiting delay is bounded. (ii) The impact of longer-than-scheduled gate-occupancy times in a time window on gate-waiting delay can be unbounded and gate-waiting delay can increase linearly as the disruption level increases. (iii) Small reductions in gate availability have a small impact on gate-waiting delay due to slack gate capacity, while larger reductions have a non-linear impact as slack gate capacity is used up. Simulation results show the following effects of mitigation strategies: (i) Implementing common gates is an effective mitigation strategy, especially for airports with a flight schedule not dominated by one carrier, such as LGA. (ii) The overnight off-gate rule is effective in mitigating gate-waiting delay for flights stranded overnight following departure cancellations. This is especially true at airports where the gate utilization is at maximum overnight, such as LGA and DFW. The overnight off-gate rule can also be very effective to mitigate gate-waiting delay due to operational disruptions in evenings. (iii) Self-docking gates are effective in mitigating gate-waiting delay due to reduced gate availability.

The luminescence and decay enhancement by variation in atomic size of alkaline earth metals in Pr3+ incorporated sodium lead borate glass

NASA Astrophysics Data System (ADS)

Lenkennavar, Susheela K.; Madhu, A.; Eraiah, B.; Kokila, M. K.

2018-05-01

The glasses used for the present study are prepared by the melting and quenching techniques of composition 20Na2O-10PbO-10MO-60B2O3-xPr2O3 (where, M=Ba, Ca, Sr and x= 0.5 mol% of Pr3+). For different alkaline considered with same Pr3+ concemtartion incorporation on present work as resulted in interesting facts. Due to the effect of different atomic size, the luminescence and life time of glasses are affected. Only for calcium alkaline earth metal incorporated samples has proved to have highest intensity in emission and longer life time. The detailed studies of them have been reported for the better understanding.

A Two-Timescale Response to Ozone Depletion: Importance of the Background State

NASA Astrophysics Data System (ADS)

Seviour, W.; Waugh, D.; Gnanadesikan, A.

2015-12-01

It has been recently suggested that the response of Southern Ocean sea-ice extent to stratospheric ozone depletion is time-dependent; that the ocean surface initially cools due to enhanced northward Ekman drift caused by a poleward shift in the eddy-driven jet, and then warms after some time due to upwelling of warm waters from below the mixed layer. It is therefore possible that ozone depletion could act to favor a short-term increase in sea-ice extent. However, many uncertainties remain in understanding this mechanism, with different models showing widely differing time-scales and magnitudes of the response. Here, we analyze an ensemble of coupled model simulations with a step-function ozone perturbation. The two-timescale response is present with an approximately 30 year initial cooling period. The response is further shown to be highly dependent upon the background ocean temperature and salinity stratification, which is influenced by both natural internal variability and the isopycnal eddy mixing parameterization. It is suggested that the majority of inter-model differences in the Southern Ocean response to ozone depletion is caused by differences in stratification.

Application of symbolic/numeric matrix solution techniques to the NASTRAN program

NASA Technical Reports Server (NTRS)

Buturla, E. M.; Burroughs, S. H.

1977-01-01

The matrix solving algorithm of any finite element algorithm is extremely important since solution of the matrix equations requires a large amount of elapse time due to null calculations and excessive input/output operations. An alternate method of solving the matrix equations is presented. A symbolic processing step followed by numeric solution yields the solution very rapidly and is especially useful for nonlinear problems.

Brief Report: Accuracy and Response Time for the Recognition of Facial Emotions in a Large Sample of Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Fink, Elian; de Rosnay, Marc; Wierda, Marlies; Koot, Hans M.; Begeer, Sander

2014-01-01

The empirical literature has presented inconsistent evidence for deficits in the recognition of basic emotion expressions in children with autism spectrum disorders (ASD), which may be due to the focus on research with relatively small sample sizes. Additionally, it is proposed that although children with ASD may correctly identify emotion…

Distributed processing for features improvement in real-time portable medical devices.

PubMed

Mercado, Erwin John Saavedra

2008-01-01

Portable biomedical devices are being developed and incorporated in daily life. Nevertheless, their standalone capacity is diminished due to the lack of processing power required to face such duties as for example, signal artifacts robustness in EKG monitor devices. The following paper presents a multiprocessor architecture made from simple microcontrollers to provide an increase in processing performance, power consumption efficiency and lower cost.

Improved work zone design guidelines and enhanced model of travel delays in work zones : Phase I, portability and scalability of interarrival and service time probability distribution functions for different locations in Ohio and the establishment of impr

DOT National Transportation Integrated Search

2006-01-01

Problem: Work zones on heavily traveled divided highways present problems to motorists in the form of traffic delays and increased accident risks due to sometimes reduced motorist guidance, dense traffic, and other driving difficulties. To minimize t...

Monitoring flood extent and area through multi-sensor, multi-temporal remote sensing: the Strymonas (Greece) river flood

NASA Astrophysics Data System (ADS)

Refice, Alberto; Tijani, Khalid; Lovergine, Francesco P.; D'Addabbo, Annarita; Nutricato, Raffaele; Morea, Alberto

2017-04-01

Satellite monitoring of flood events at high spatial and temporal resolution is considered a difficult problem, mainly due to the lack of data with sufficient acquisition frequency and timeliness. The problem is worsened by the typically cloudy weather conditions associated to floods, which obstacle the propagation of e.m. waves in the optical spectral range, forbidding acquisitions by optical sensors. This problem is not present for longer wavelengths, so that radar imaging sensors are recognized as viable solutions for long-term flood monitoring. In selected cases, however, weather conditions may remain clear for sufficient amounts of time, enabling monitoring of the evolution of flood events through long time series of satellite images, both optical and radar. In this contribution, we present a case study of long-term integrated monitoring of a flood event which affected part of the Strymonas river basin, a transboundary river with source in Bulgaria, which flows then through Greece up to the Aegean Sea. The event, which affected the floodplain close to the river mouth, started at the beginning of April 2015, due to heavy rain, and lasted for several months, with some water pools still present at the beginning of September. Due to the arid climate characterizing the area, weather conditions were cloud-free for most of the period covering the event. We collected one high-resolution, X-band, COSMO-SkyMed, 5 C-band, Sentinel-1 SAR images, and 11 optical Landsat-8 images of the area. SAR images were calibrated, speckle-filtered and precisely geocoded; optical images were radiometrically corrected to obtain ground reflectance values from which NDVI maps were derived. The images were then thresholded to obtain binary flood maps for each day. Threshold values for microwave and optical data were calibrated by comparing one SAR and one optical image acquired on the same date. Results allow to draw a multi-temporal map of the flood evolution with high temporal resolution. The extension of flooded area can also be tracked in time, allowing to envisage testing of evapotranspiration/absorption models.

New Measurements of Mars Thermospheric Variability from MAVEN EUVM Solar Occultations

NASA Astrophysics Data System (ADS)

Thiemann, E.; Eparvier, F. G.; Andersson, L.; Pilinski, M.; Chamberlin, P. C.; Fowler, C. M.; Dominique, M.; Bougher, S. W.; Gröller, H.; Girazian, Z.; Lillis, R. J.

2017-12-01

The Mars thermosphere encompasses both the coldest and hottest regions of the Mars neutral atmosphere, where temperatures warm from below 150 K at the well-mixed homopause to 300 K at the collisionless exobase, and change by comparable magnitudes over the diurnal cycle. In this dynamic and highly-structured region, atoms and molecules are accelerated by a number of processes, potentially leading to escape and permanent loss to space. Increasingly, evidence shows that atmospheric escape to space has resulted in the loss of a substantial portion of Mars's atmosphere over the planet's history. Given that the thermosphere is the neutral reservoir for atmospheric escape, understanding how and why it varies is crucial for understanding how Mars's climate has evolved over time. The Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter's Extreme Ultraviolet (EUV) Monitor (EUVM) has recently demonstrated the capability to measure thermospheric density from 100 to 200 km with solar occultations of its 17-22 nm channel. These measurements are routine, inherently constrained to either 06:00 or 18:00 Local Time, and span all latitudes, a number of which have been revisited multiple times over the past 3 Earth years due to MAVEN's orbital precession. These factors, coupled with uncertainties in retrieved densities below 10%, make MAVEN EUVM occultations ideal for tracking both long-term and latitudinal thermospheric variability. Some notable trends revealed by the EUVM occultation data are variations in poleward warming due to changes in global circulation patterns, planetary-scale waves due to varying gravity wave or tidal forcing, and temperature due to solar EUV variability. In this study, we present these new measurements in detail. We begin by briefly presenting the measurement methods and uncertainties, and show an overview of the measurements made to-date, putting them in the context of observations made by other missions, other instruments onboard MAVEN, and the newly arrived ExoMars Trace Gas Orbiter (TGO). We then show observations of latitudinal and seasonal temperature and density variability made over the MAVEN mission, and discuss the possible underlying causes. We conclude by discussing plans to make these new data publically available as an official MAVEN data product.

Pretest reference calculation for the 18-W/m/sup 2/ Mockup for Defense High-Level Waste (WIPP Room A in situ experiment)

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

Morgan, H.S.; Stone, C.M.

A pretest reference calculation for the 18-W/m/sup 2/ Mockup for Defense High-Level Waste (DHLW) or Room A experiment is presented in this report. The mockup is one of several large scale in situ experiments currently under construction near Carlsbad, New Mexico, at the site of the Waste Isolation Pilot Plant (WIPP). The 18-W/m/sup 2/ test is an in situ experiment developed to simulate closely the Reference Repository Conditions (RRC) for DHLW in salt. The test consists of three long, parallel rooms (A1, A2, A3) which are heated by canister heaters placed in the floor of each room. These heaters producemore » thermal loading which simulates an areal heat output of 18-W/m/sup 2/ for Room A2, which is the focus of the experiment. This load will be supplied for a period of three years. Rooms A1, A2, and A3 are heavily instrumented for monitoring both temperature increases due to the thermal loading and deformations due to creep of the salt. Data from the experiment are not available at the present time, but the measurements for Room A2 will eventually be compared to the results for Room A2 presented here to assess and improve thermal and mechanical modeling capabilities for the WIPP. The thermal/structural model used here represents the state-of-the-art at the present time. A large number of plots are included since an appropriate result is presented for every Room A2 gauge location. 55 refs., 70 figs., 4 tabs.« less

Hemostatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus.

PubMed

Verschoof, J; Moritz, A; Kramer, M; Bauer, N

2015-01-01

Prospective characterization of hemostastatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus (GDV). Coagulation variables (platelets, prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen, antithrombin [AT], protein C [PC], protein S [PS], D-dimers), plasma lactate concentration and inflammatory biomarkers (C-reactive protein, white blood cell [WBC] count, lymphocyte and neutrophil numbers) were assessed in 20 dogs with GDV presented between 2011 and 2012. Blood was taken preoperatively and at days 1 and 3 postoperatively. The prognostic value of these variables before and after surgery was evaluated as well as the behavior of variables during the study. Overall, 7/20 (35%) dogs did not survive; two dogs (29%) were euthanized during surgery due to severe gastric necrosis and 5 (71%) dogs after surgery due to sepsis and disseminated intravascular coagulopathy. Prior to surgery, median plasma lactate concentration was significantly (p = 0.01) lower in survivors (6.2 mmol/l, range 1.9-9.7 mmol/l) when compared to non-survivors (11.8 mmol/l, range 7.5-16.2 mmol/l). In dogs dying after surgery, significantly higher plasma lactate concentration, coagulation times and D-dimer concentration were present as well as lower fibrinogen concentration and activity of PC and AT compared to survivors. At discharge, activity of AT, PC and PS were markedly below the reference interval in 6/13 (46%), 11/13 (85%), and 8/13 (62%) dogs, respectively. Only lactate plasma concentration was of preoperative prognostic value. After surgery, severe abnormalities of coagulation variables, especially the endogenous anticoagulants were present in most of the dogs. The severity of the abnormalities was associated with survival.

Compound Extremes and Bunched Black (or Grouped Grey) Swans.

NASA Astrophysics Data System (ADS)

Watkins, Nicholas

2013-04-01

Observed "wild" natural fluctuations may differ substantially in their character. Some events may be genuinely unforeseen (and unforeseeable), as with Taleb's "black swans". These may occur singly, or may have their impact further magnified by being ``bunched" in time. Some of the others may, however, be the rare extreme events from a light-tailed underlying distribution. Studying their occurrence may then be tractable with the methods of extreme value theory [e.g. Coles, 2001], suitably adapted to allow correlation if that is observed to be present. Yet others may belong to a third broad class, described in today's presentation [ reviewed in Watkins, GRL Frontiers, 2013, doi: 10.1002/grl.50103]. Such "bursty" time series may show comparatively frequent high amplitude events, and/or long range correlations between successive values. The frequent large values due to the first of these effects, modelled in economics by Mandelbrot in 1963 using heavy- tailed probability distributions, can give rise to an "IPCC type I" burst composed of successive wild events. Conversely, long range dependence, even in a light-tailed Gaussian model like Mandelbrot and van Ness' fractional Brownian motion, can integrate ``mild" events into an extreme "IPCC type III" burst. I will show how a standard statistical time series model, linear fractional stable motion (LFSM), which descends from the two special cases advocated by Mandelbrot, allows these two effects to be varied independently, and will present results from a preliminary study of such bursts in LFSM. The consequences for burst scaling when low frequency effects due to dissipation (FARIMA models), and multiplicative cascades (such as multifractals) are included will also be discussed, and the physical assumptions and constraints associated with making a given choice of model.

Compound Extremes and Bunched Black (or Grouped Grey) Swans

NASA Astrophysics Data System (ADS)

Watkins, N. W.

2014-12-01

Observed "wild" natural fluctuations may differ substantially in their character. Some events may be genuinelyunforeseen (and unforeseeable), as with Taleb's "black swans". These may occur singly, or may have their impactfurther magnified by being "bunched" in time. Some of the others may, however, be the rare extreme events from alight-tailed underlying distribution. Studying their occurrence may then be tractable with the methods of extremevalue theory [e.g. Coles, 2001], suitably adapted to allow correlation if that is observed to be present. Yet others may belong to a third broad class, described in today's presentation [ reviewed in Watkins, GRLFrontiers, 2013, doi: 10.1002/grl.50103]. Such "bursty" time series may show comparatively frequent highamplitude events, and/or long range correlations between successive values. The frequent large values due to thefirst of these effects, modelled in economics by Mandelbrot in 1963 using heavy- tailed probability distributions,can give rise to an "IPCC type I" burst composed of successive wild events. Conversely, long range dependence,even in a light-tailed Gaussian model like Mandelbrot and van Ness' fractional Brownian motion, can integrate"mild" events into an extreme "IPCC type III" burst. I will show how a standard statistical time series model, linear fractional stable motion (LFSM), which de-scends from the two special cases advocated by Mandelbrot, allows these two effects to be varied independently,and will present results from a preliminary study of such bursts in LFSM. The consequences for burst scaling whenlow frequency effects due to dissipation (FARIMA models), and multiplicative cascades (such as multifractals)are included will also be discussed, and the physical assumptions and constraints associated with making a givenchoice of model.

Impact of charge-transfer excitons in regioregular polythiophene on the charge separation at polythiophene-fullerene heterojunctions

NASA Astrophysics Data System (ADS)

Polkehn, M.; Tamura, H.; Burghardt, I.

2018-01-01

This study addresses the mechanism of ultrafast charge separation in regioregular oligothiophene-fullerene assemblies representative of poly-3-hexylthiophene (P3HT)-[6,6]-phenyl-C61 butyric acid methyl ester (PCBM) heterojunctions, with special emphasis on the inclusion of charge transfer excitons in the oligothiophene phase. The formation of polaronic inter-chain charge separated species in highly ordered oligothiophene has been demonstrated in recent experiments and could have a significant impact on the net charge transfer to the fullerene acceptor. The present approach combines a first-principles parametrized multi-site Hamiltonian, based on time-dependent density functional theory calculations, with accurate quantum dynamics simulations using the multi-layer multi-configuration time-dependent Hartree method. Quantum dynamical studies are carried out for up to 182 electronic states and 112 phonon modes. The present analysis follows up on our previous study of (Huix-Rotllant et al 2015 J. Phys. Chem. Lett. 6 1702) and significantly expands the scope of this analysis by including the dynamical role of charge transfer excitons. Our investigation highlights the pronounced mixing of photogenerated Frenkel excitons with charge transfer excitons in the oligothiophene domain, and the opening of new transfer channels due the creation of such charge-separated species. As a result, it turns out that the interfacial donor/acceptor charge transfer state can be largely circumvented due to the presence of charge transfer excitons. However, the latter states in turn act as a trap, such that the free carrier yield observed on ultrafast time scales is tangibly reduced. The present analysis underscores the complexity of the transfer pathways at P3HT-PCBM type junctions.

Dead time corrections using the backward extrapolation method

NASA Astrophysics Data System (ADS)

Gilad, E.; Dubi, C.; Geslot, B.; Blaise, P.; Kolin, A.

2017-05-01

Dead time losses in neutron detection, caused by both the detector and the electronics dead time, is a highly nonlinear effect, known to create high biasing in physical experiments as the power grows over a certain threshold, up to total saturation of the detector system. Analytic modeling of the dead time losses is a highly complicated task due to the different nature of the dead time in the different components of the monitoring system (e.g., paralyzing vs. non paralyzing), and the stochastic nature of the fission chains. In the present study, a new technique is introduced for dead time corrections on the sampled Count Per Second (CPS), based on backward extrapolation of the losses, created by increasingly growing artificially imposed dead time on the data, back to zero. The method has been implemented on actual neutron noise measurements carried out in the MINERVE zero power reactor, demonstrating high accuracy (of 1-2%) in restoring the corrected count rate.

Effects of computing time delay on real-time control systems

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Cui, Xianzhong

1988-01-01

The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

Trends in insect repellent formulations: A review.

PubMed

Tavares, Melanie; da Silva, Márcio Robert Mattos; de Oliveira de Siqueira, Luciana Betzler; Rodrigues, Raphaela Aparecida Schuenck; Bodjolle-d'Almeida, Lolita; Dos Santos, Elisabete Pereira; Ricci-Júnior, Eduardo

2018-03-25

The use of natural and synthetic repellents, marketed in different pharmaceutical forms, is growing in the world due to the emerging vector-borne viral diseases as Dengue, Zika, Chikungunya, Yellow Fever and Malaria. The choice of the ideal formulation will depend on a series of factors to be analyzed: type of repellent active (natural or synthetic), pharmaceutical forms (spray, lotion, cream, gel), action time duration (short or long), environment of exposure and the user (adult, pregnant women, children, newborn). The most used repellents are DEET, IR3535 (Ethyl Butylacetylaminopropionate) (EB), Icaridin (Picaridin) and essential oils, each of them presenting advantages and disadvantages. DEET is the oldest and the most powerful repellent available in the market, thus being the reference standard. For this reason, there are many classic formulations available in the market containing the chemical component DEET in spray forms and lotions. However, due to its toxicity, DEET is not recommended for children up to 6 months and pregnant women. DEET has been an option along with other market-shared products as IR3535 and Icaridin (Picaridin), which present less toxicity in their composition. IR3535 is the less toxic and may be prescribed for children over 6 months of age and pregnant women so that they have been the best option because of the lower toxicity levels presented. IR3535 is the one that has the lowest toxicity level among the three options and may be prescribed for children above 6 months of age and pregnant women. Icaridin is as potent as DEET, but less toxic, and has the advantage of having the long-lasting action among the aforementioned repellents. The new formulations have been based on controlled release systems (CRS). The CRSs for repellents comprise polymer micro/nanocapsules, micro/solid lipid nanoparticles, nanoemulsions/microemulsions, liposomes/niosomes, nanostructured hydrogels and cyclodextrins. There are many formulations based on micro and nanocapsules containing DEET and essential oils to increase repellent action time duration and decrease permeation and consequently, systemic toxicity. The development of new formulations for the IR3535 and Icaridin is a research field yet to be explored. The current trend is the use of natural repellent actives such as essential oils, which present low toxicity, do not harm the environment, but present reduced repellent action time due to rapid evaporation after skin application. CRSs have been used as vehicle of natural repellents to improve long-lasting repellent action, reduce skin permeation and systemic effects. Copyright © 2018 Elsevier B.V. All rights reserved.

A position- and time-sensitive photon-counting detector with delay- line read-out

NASA Astrophysics Data System (ADS)

Jagutzki, Ottmar; Dangendorf, Volker; Lauck, Ronald; Czasch, Achim; Milnes, James

2007-05-01

We have developed image intensifier tubes with delay-anode read-out for time- and position-sensitive photon counting. The timing precision is better than 1 ns with 1000x1000 pixels position resolution and up to one megacounts/s processing rate. Large format detectors of 40 and 75 mm active diameter with internal helical-wire delay-line anodes have been produced and specified. A different type of 40 and 25 mm tubes with semi-conducting screen for image charge read-out allow for an economic and robust tube design and for placing the read-out anodes outside the sealed housing. Two types of external delay-line anodes, i.e. pick-up electrodes for the image charge, have been tested. We present tests of the detector and anode performance. Due to the low background this technique is well suited for applications with very low light intensity and especially if a precise time tagging for each photon is required. As an example we present the application of scintillator read-out in time-of-flight (TOF) neutron radiography. Further applications so far are Fluorescence Life-time Microscopy (FLIM) and Astronomy.

Effect of the RC time on photocurrent transients and determination of charge carrier mobilities

NASA Astrophysics Data System (ADS)

Kniepert, Juliane; Neher, Dieter

2017-11-01

We present a closed analytical model to describe time dependent photocurrents upon pulsed illumination in the presence of an external RC circuit. In combination with numerical drift diffusion simulations, it is shown that the RC time has a severe influence on the shape of the transients. In particular, the maximum of the photocurrent is delayed due to a delayed recharging of the electrodes. This delay increases with the increasing RC constant. As a consequence, charge carrier mobilities determined from simple extrapolation of the initial photocurrent decay will be in general too small and feature a false dependence on the electric field. Here, we present a recipe to correct charge carrier mobilities determined from measured photocurrent transients by taking into account the RC time of the experimental set-up. We also demonstrate how the model can be used to more reliably determine the charge carrier mobility from experimental data of a typical polymer/fullerene organic solar cell. It is shown that further aspects like a finite rising time of the pulse generator and the current contribution of the slower charger carriers influence the shape of the transients and may lead to an additional underestimation of the transit time.

Structural health monitoring of pipelines rehabilitated with lining technology

NASA Astrophysics Data System (ADS)

Farhidzadeh, Alireza; Dehghan-Niri, Ehsan; Salamone, Salvatore

2014-03-01

Damage detection of pipeline systems is a tedious and time consuming job due to digging requirement, accessibility, interference with other facilities, and being extremely wide spread in metropolitans. Therefore, a real-time and automated monitoring system can pervasively reduce labor work, time, and expenditures. This paper presents the results of an experimental study aimed at monitoring the performance of full scale pipe lining systems, subjected to static and dynamic (seismic) loading, using Acoustic Emission (AE) technique and Guided Ultrasonic Waves (GUWs). Particularly, two damage mechanisms are investigated: 1) delamination between pipeline and liner as the early indicator of damage, and 2) onset of nonlinearity and incipient failure of the liner as critical damage state.

Manned Mars flyby mission and configuration concept

NASA Technical Reports Server (NTRS)

Young, Archie; Meredith, Ollie; Brothers, Bobby

1986-01-01

A concept is presented for a flyby mission of the planet. The mission was sized for the 2001 time period, has a crew of three, uses all propulsive maneuvers, and requires 442 days. Such a flyby mission results in significantly smaller vehicles than would a landing mission, but of course loses the value of the landing and the associated knowledge and prestige. Stay time in the planet vicinity is limited to the swingby trajectory but considerable time still exists for enroute science and research experiments. All propulsive braking was used in the concept due to unacceptable g-levels associated with aerobraking on this trajectory. LEO departure weight for the concept is approximately 594,000 pounds.

Monitoring of In-Situ Remediation By Time Lapse 3D Geo-Electric Measurements

NASA Astrophysics Data System (ADS)

Kanli, A. I.; Tildy, P.; Neducza, B.; Nagy, P.; Hegymegi, C.

2017-12-01

Injection of chemical oxidant solution to degrade the subsurface contaminants can be used for hydrocarbon contamination remediation. In this study, we developed a non-destructive measurement strategy to monitor oxidative in-situ remediation processes. The difficulties of the presented study originate from the small volume of conductive solution that can be used due to environmental considerations. Due to the effect of conductive groundwater and the high clay content of the targeted layer and the small volume of conductive solution that can be used due to environmental considerations, a site specific synthetic modelling is necessary for measurement design involving the results of preliminary 2D ERT measurements, electrical conductivity measurements of different active agents and expected resistivity changes calculated by soil resistivity modelling. Because of chemical biodegradation, the results of soil resistivity modelling have suggested that the reagent have complex effects on contaminated soils. As a result the plume of resistivity changes caused by the injected agent was determined showing strong fracturing effect because of the high pressure of injection. 3D time-lapse geo-electric measurements were proven to provide a usable monitoring tool for in-situ remediation as a result of our sophisticated tests and synthetic modelling.

Smart Photonic Carbon Brush: FBG Length as Sensing Parameter

NASA Astrophysics Data System (ADS)

Morozov, O. G.; Nureev, I. I.; Kuznetsov, A. A.; Artemiev, V. I.

2018-04-01

This article deals with problem of carbon brush’s length measurements. There are many applications where regular inspection is not feasible because of a number of factors including, for example, time, labor, cost and disruptions due to down time. Thus, there is a need for a system that can monitor the brush’s length to calculate it’s wear rate, while the component is in operation or without removing of the component from its operational position. We propose a novel method for characterization of carbon brush’s length. This method based on the usage of advantages of the multiplicative response of FBGs and FBG arrays: spectral parameters depend on several aspects, such as grating’s period, refractive index, it’s physical length and so on. We are the first, in our point of view, who proposed to use third parameter for sensing application and prospectively all three parameters for complex measurement: the change of FBG’s length is used to measure length of the brush and it’s wear rate, grating’s central wavelength shift for temperature (due to refractive index change) and mechanical stress (due to grating’s period variations) measurements. The results of modelling and experiments are presented.

Subsonic stability and control flight test results of the Space Shuttle /tail cone off/

NASA Technical Reports Server (NTRS)

Cooke, D. R.

1980-01-01

The subsonic stability and control testing of the Space Shuttle Orbiter in its two test flights in the tailcone-off configuration is discussed, and test results are presented. Flight test maneuvers were designed to maximize the quality and quantity of stability and control data in the minimal time allotted using the Space Shuttle Functional Simulator and the Modified Maximum Likelihood Estimator (MMLE) programs, and coefficients were determined from standard sensor data sets using the MMLE, despite problems encountered in timing due to the different measurement systems used. Results are included for lateral directional and longitudinal maneuvers as well as the Space Shuttle aerodynamic data base obtained using the results of wind tunnel tests. The flight test data are found to permit greater confidence in the data base since the differences found are well within control system capability. It is suggested that the areas of major differences, including lateral directional data with open speedbrake, roll due to rudder and normal force due to elevon, be investigated in any further subsonic flight testing. Improvements in sensor data and data handling techniques for future orbital test flights are indicated.

A Fast Evaluation Method for Energy Building Consumption Based on the Design of Experiments

NASA Astrophysics Data System (ADS)

Belahya, Hocine; Boubekri, Abdelghani; Kriker, Abdelouahed

2017-08-01

Building sector is one of the effective consumer energy by 42% in Algeria. The need for energy has continued to grow, in inordinate way, due to lack of legislation on energy performance in this large consumer sector. Another reason is the simultaneous change of users’ requirements to maintain their comfort, especially summer in dry lands and parts of southern Algeria, where the town of Ouargla presents a typical example which leads to a large amount of electricity consumption through the use of air conditioning. In order to achieve a high performance envelope of the building, an optimization of major parameters building envelope is required, using design of experiments (DOE), can determine the most effective parameters and eliminate the less importance. The study building is often complex and time consuming due to the large number of parameters to consider. This study focuses on reducing the computing time and determines the major parameters of building energy consumption, such as area of building, factor shape, orientation, ration walls to windows …etc to make some proposal models in order to minimize the seasonal energy consumption due to air conditioning needs.

Management of a Fulminant Upper Gastrointestinal Bleeding Exteriorized Through Hemobilia Due to Arteriobiliary Fistula Between the Common Bile Duct and a Right Hepatic Artery Aneurysm – A Case Report

PubMed Central

BACALBASA, NICOLAE; BREZEAN, IULIAN; ANGHEL, CLAUDIU; BARBU, ION; PAUTOV, MIHAI; BALESCU, IRINA; BRASOVEANU, VLADISLAV

2017-01-01

Right hepatic artery aneurysms are rare events that might remain asymptomatic for a long period of time. However, in cases presenting large lesions, symptoms might develop especially due to the association of compression of the surrounding elements. Most often these symptoms and signs include diffuse abdominal pain, jaundice or portal vein compression signs. In rare cases life-threatening complications might develop due to the aneurysmal erosion of the biliary duct, portal vein or due to the aneurysmal rupture in the peritoneal cavity. In all these cases emergency surgery is imposed. We present the case of a 66-year-old patient diagnosed with a partially thrombosed right hepatic artery aneurysm compressing the common bile duct who was initially submitted to a percutaneous arterial embolization of the aneurysm in association with an external biliary drainage; three weeks later the patient presented a fulminant upper gastrointestinal bleeding exteriorized through the external biliary drainage, hematemesis and hematochezia. The patient was successfully submitted to surgery, intraoperatively a synchronous rupture of the portal vein being revealed. The right hepatic artery aneurysm was resected en bloc with common bile duct resection and segmental portal vein resection. The continuity of the portal vein was re-established through the interposition of a cadaveric allograft, the common bile duct was anastomosed with en Roux en Y limb while the right hepatic artery aneurysm was ligated and resected, the arterial vascularization of the liver being provided by the left hepatic artery. PMID:28882970

Neuroblastoma-associated paraneoplastic syndrome with anti-Hu antineuronal antibodies presenting at the time of recurrence.

PubMed

Mpofu, C; Sztriha, L; Revesz, T

1996-01-01

A 27-month-old girl presented with chest pain. Further evaluation confirmed posterior mediastinal neuroblastoma with bone marrow infiltration, which was treated with a combination of chemotherapy and surgery. Four months after completing treatment, she presented with myoclonus and weakness of her right arm. The myoclonus eventually subsided but her right arm weakness progressed to a right hemiplegia. High titers of antineuronal nuclear antibodies identified as anti-Hu were found in both serum and cerebrospinal fluid. One month later she presented with a relapse of her original tumor, from which she died. Identification of anti-Hu antineuronal nuclear antibodies in this neuroblastoma-associated paraneoplastic syndrome supports the hypothesis that the syndrome is due to autoimmune disease.

Five-year study of ocular injuries due to fireworks in India.

PubMed

Malik, Archana; Bhala, Soniya; Arya, Sudesh K; Sood, Sunandan; Narang, Subina

2013-08-01

To study the demographic profile, cause, type and severity of ocular injuries, their complications and final visual outcome following fireworks around the time of Deepawali in India. Case records of patients who presented with firework-related injuries during 2005-2009 at the time of Deepawali were reviewed. Data with respect to demographic profile of patients, cause and time of injury, time of presentation and types of intervention were analyzed. Visual acuity at presentation and final follow-up, anterior and posterior segment findings, and any diagnostic and surgical interventions carried out were noted. One hundred and one patients presented with firework-related ocular injuries, of which 77.5 % were male. The mean age was 17.60 ± 11.9 years, with 54 % being ≤14 years of age. The mean time of presentation was 8.9 h. Seventeen patients had open globe injury (OGI) and 84 had closed globe injury (CGI). Fountains were the most common cause of CGI and bullet bombs were the most common cause of OGI. Mean log MAR visual acuity at presentation was 0.64 and 1.22 and at last follow-up was 0.09 and 0.58 for CGI and OGI, respectively (p < 0.05). Patients with CGI had a better visual outcome. Three patients with OGI developed permanent blindness. Factors associated with poor visual outcome included poor initial visual acuity, OGI, intraocular foreign body (IOFB), retinal detachment and development of endophthalmitis. Firework injuries were seen mostly in males and children. Poor visual outcome was associated with poor initial visual acuity, OGI, IOFB, retinal detachment and development of endophthalmitis, while most patients with CGI regained good vision.

Primary Amenorrhea Associated with Hyperprolactinemia in Polyglandular Autoimmune Syndrome Type II: A Case Report.

PubMed

Cottas, Luiza Tizziotti; Borges, Maria de Fátima; Oliveira, Lívia Prata Santos; Resende, Ana Luísa Mantovani; Ataíde, Meire Soares; Resende, Elisabete Aparecida Mantovani Rodrigues

2018-06-27

Polyglandular autoimmune syndrome type II (PGA-II) is a rare immunoendocrinopathy syndrome characterized by the occurrence of autoimmune Addison disease along with diabetes mellitus type 1 and/or autoimmune thyroid disease. Here, we report the case of a 23-year-old female with PGA-II who was followed up at the dermatology and endocrinology clinics of the Universidade Federal do Triângulo Mineiro, located in the state of Minas Gerais, Brazil. First, the patient presented diffuse skin hyperpigmentation, vitiligo; and in sequence, due to vomiting, appetite and weight loss, hypoglycemia, amenorrhea, and galactorrhea, the patient was then diagnosed with PGA-II. The patient also presented intense hyperprolactinemia due to primary hypothyroidism. The late diagnosis of PGA-II is frequent because the disorder is uncommon and has non-specific clinical manifestations. This report emphasizes the significance of a timely diagnosis and appropriate treatment to reduce morbidity and mortality associated with these diseases, especially Addison disease. The present study reports a rare case of a patient with PGA-II with primary amenorrhea associated with hyperprolactinemia. Thieme Revinter Publicações Ltda Rio de Janeiro, Brazil.

Review of the applications of x-ray refraction and the x-ray waveguide phenomenon to estimation of film structures.

PubMed

Hayashi, Kouichi

2010-12-01

Based on our previous work, I review the applications of x-ray refraction and the x-ray waveguide phenomenon to organic and inorganic thin films in the present paper. Under grazing incidence conditions, observations of refracted x-rays and guided x-rays due to the x-ray waveguide phenomenon provide information about thin film structures, and thus have potential as alternative methods to x-ray reflectivity. To date, we have measured the spectra of the refracted x-rays and guided x-rays from end faces of thin films using white incident x-ray beams, and utilized them for the determination of film density and thickness. Some of this work is summarized in the present paper. At the end of this paper, I describe our recent achievement in this field, namely the in situ measurement of guided x-rays during the film degradation process due to strong synchrotron radiation damage. Moreover, I discuss the perspective of the present technique from the viewpoint of micro-characterization and real-time estimation of thin films.

Elevating Baseline Activation Does Not Facilitate Reading of Unattended Words

NASA Technical Reports Server (NTRS)

Lien, Mei-Ching; Kouchi, Scott; Ruthruff, Eric; Lachter, Joel B.

2009-01-01

Previous studies have disagreed the extent to which people extract meaning from words presented outside the focus of spatial attention. The present study, examined a possible explanation for such discrepancies, inspired by attenuation theory: unattended words can be read more automatically when they have a high baseline level of activation (e.g., due to frequent repetition or due to being expected in a given context). We presented a brief prime word in lowercase, followed by a target word in uppercase. Participants indicated whether the target word belonged to a particular category (e.g., "sport"). When we drew attention to the prime word using a visual cue, the prime produced substantial priming effects on target responses (i.e., faster responses when the prime and target words were identical or from the same category than when they belonged to different categories). When prime words were not attended, however, they produced no priming effects. This finding replicated even when there were only 4 words, each repeated 160 times during the experiment. Even with a very high baseline level of activation, it appears that very little word processing is possible without spatial attention.

Potentials evoked by chirp-modulated tones: a new technique to evaluate oscillatory activity in the auditory pathway.

PubMed

Artieda, J; Valencia, M; Alegre, M; Olaziregi, O; Urrestarazu, E; Iriarte, J

2004-03-01

Steady-state potentials are oscillatory responses generated by a rhythmic stimulation of a sensory pathway. The frequency of the response, which follows the frequency of stimulation, is maximal at a stimulus rate of 40 Hz for auditory stimuli. The exact cause of these maximal responses is not known, although some authors have suggested that they might be related to the 'working frequency' of the auditory cortex. Testing of the responses to different frequencies of stimulation may be lengthy if a single frequency is studied at a time. Our aim was to develop a fast technique to explore the oscillatory response to auditory stimuli, using a tone modulated in amplitude by a sinusoid whose frequency increases linearly in frequency ('chirp') from 1 to 120 Hz. Time-frequency transforms were used for the analysis of the evoked responses in 10 subjects. Also, we analyzed whether the peaks in these responses were due to increases of amplitude or to phase-locking phenomena, using single-sweep time-frequency transforms and inter-trial phase analysis. The pattern observed in the time-frequency transform of the chirp-evoked potential was very similar in all subjects: a diagonal band of energy was observed, corresponding to the frequency of modulation at each time instant. Two components were present in the band, one around 45 Hz (30-60 Hz) and a smaller one between 80 and 120 Hz. Inter-trial phase analysis showed that these components were mainly due to phase locking phenomena. A simultaneous testing of the amplitude-modulation-following oscillatory responses to auditory stimulation is feasible using a tone modulated in amplitude at increasing frequencies. The maximal energies found at stimulation frequencies around 40 Hz are probably due to increased phase-locking of the individual responses.

Greenhouse Impact Due to the Use of Combustible Fuels: Life Cycle Viewpoint and Relative Radiative Forcing Commitment

PubMed Central

Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

2008-01-01

Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels. PMID:18521657

Greenhouse impact due to the use of combustible fuels: life cycle viewpoint and relative radiative forcing commitment.

PubMed

Kirkinen, Johanna; Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

2008-09-01

Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels.

The Resistive-Wall Instability in Multipulse Linear Induction Accelerators

DOE PAGES

Ekdahl, Carl

2017-05-01

The resistive-wall instability results from the Lorentz force on the beam due to the beam image charge and current. If the beam pipe is perfectly conducting, the electric force due to the image charge attracts the beam to the pipe wall, and the magnetic force due to the image current repels the beam from the wall. For a relativistic beam, these forces almost cancel, leaving a slight attractive force, which is easily overcome by external magnetic focusing. However, if the beam pipe is not perfectly conducting, the magnetic field due to the image current decays on a magnetic-diffusion time scale.more » If the beam pulse is longer than the magnetic diffusion time, the repulsion of the beam tail will be weaker than the repulsion of the beam head. In the absence of an external focusing force, this causes a head-to-tail sweep of the beam toward the wall. This instability is usually thought to be a concern only for long-pulse relativistic electron beams. However, with the advent of multipulse, high current linear induction accelerators, the possibility of pulse-to-pulse coupling of this instability should be investigated. Lastly, we have explored pulse-to-pulse coupling using the linear accelerator model for Dual Axis Radiography for Hydrodynamic Testing beam dynamics code, and we present the results of this paper.« less

The Resistive-Wall Instability in Multipulse Linear Induction Accelerators

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

Ekdahl, Carl

The resistive-wall instability results from the Lorentz force on the beam due to the beam image charge and current. If the beam pipe is perfectly conducting, the electric force due to the image charge attracts the beam to the pipe wall, and the magnetic force due to the image current repels the beam from the wall. For a relativistic beam, these forces almost cancel, leaving a slight attractive force, which is easily overcome by external magnetic focusing. However, if the beam pipe is not perfectly conducting, the magnetic field due to the image current decays on a magnetic-diffusion time scale.more » If the beam pulse is longer than the magnetic diffusion time, the repulsion of the beam tail will be weaker than the repulsion of the beam head. In the absence of an external focusing force, this causes a head-to-tail sweep of the beam toward the wall. This instability is usually thought to be a concern only for long-pulse relativistic electron beams. However, with the advent of multipulse, high current linear induction accelerators, the possibility of pulse-to-pulse coupling of this instability should be investigated. Lastly, we have explored pulse-to-pulse coupling using the linear accelerator model for Dual Axis Radiography for Hydrodynamic Testing beam dynamics code, and we present the results of this paper.« less

Investigation on the energy spectrums of electrons in atmospheric pressure argon plasma jets and their dependences on the applied voltage

NASA Astrophysics Data System (ADS)

Chen, Xinxian; Tan, Zhenyu; Liu, Yadi; Li, Xiaotong; Pan, Jie; Wang, Xiaolong

2017-08-01

This work presents a systematical investigation on the spatiotemporal evolution of the energy spectrum of electrons in atmospheric pressure argon plasma jets and its dependence on the applied voltage. The investigations are carried out by means of the numerical simulation based on a particle-in-cell Monte-Carlo collision model. The characteristics of the spatiotemporal evolution of the energy spectrum of electrons (ESE) in the discharge space have been presented, and especially the mechanisms of inducing these characteristics have also been revealed. The present work shows the following conclusions. In the evolution of ESE, there is a characteristic time under each applied voltage. Before the characteristic time, the peak value of ESE decreases, the peak position shifts toward high energy, and the distribution of ESE becomes wider and wider, but the reverse is true after the characteristic time. The formation of these characteristics can be mainly attributed to the transport of electrons toward a low electric field as well as a balance between the energy gained from the electric field including the effect of space charges and the energy loss due to inelastic collisions in the process of electron transport. The characteristic time decreases with the applied voltage. In addition, the average energy of electrons at the characteristic time can be increased by enhancing the applied voltage. The results presented in this work are of importance for regulating and controlling the energy of electrons in the plasma jets applied to plasma medicine.

Antiorthostatic test as a model to study antigravity mechanisms of the cardiovascular system.

PubMed

Yarullin, K K; Vasilyeva, T D; Alekseev, D A

1976-01-01

The paper presents rheographic investigations of regional haemodynamics (brain, lungs, liver and limbs) during antiorthostatic exposures of varying intensity (-15, -30, -45 degrees, times of exposure 20, 40 and 60 min). Our findings show that the pattern and time of the function of compensatory mechanisms preventing excessive vascular compliance [correction of complicance] under the influence of the hydrostatic blood column depend on the value and length of antiorthostasis, because prolonged venous congestion results not only in congestive circulatory hypoxia but also in arterial hypoxia due to compensatory limitation of arterial inflow.

Aberrant regeneration of the third cranial nerve.

PubMed

Shrestha, U D; Adhikari, S

2012-01-01

Aberrant regeneration of the third cranial nerve is most commonly due to its damage by trauma. A ten-month old child presented with the history of a fall from a four-storey building. She developed traumatic third nerve palsy and eventually the clinical features of aberrant regeneration of the third cranial nerve. The adduction of the eye improved over time. She was advised for patching for the strabismic amblyopia as well. Traumatic third nerve palsy may result in aberrant regeneration of the third cranial nerve. In younger patients, motility of the eye in different gazes may improve over time. © NEPjOPH.

Time-splitting combined with exponential wave integrator fourier pseudospectral method for Schrödinger-Boussinesq system

NASA Astrophysics Data System (ADS)

Liao, Feng; Zhang, Luming; Wang, Shanshan

2018-02-01

In this article, we formulate an efficient and accurate numerical method for approximations of the coupled Schrödinger-Boussinesq (SBq) system. The main features of our method are based on: (i) the applications of a time-splitting Fourier spectral method for Schrödinger-like equation in SBq system, (ii) the utilizations of exponential wave integrator Fourier pseudospectral for spatial derivatives in the Boussinesq-like equation. The scheme is fully explicit and efficient due to fast Fourier transform. The numerical examples are presented to show the efficiency and accuracy of our method.

Multiple Fault Isolation in Redundant Systems

NASA Technical Reports Server (NTRS)

Pattipati, Krishna R.; Patterson-Hine, Ann; Iverson, David

1997-01-01

Fault diagnosis in large-scale systems that are products of modern technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

Multiple Fault Isolation in Redundant Systems

NASA Technical Reports Server (NTRS)

Pattipati, Krishna R.

1997-01-01

Fault diagnosis in large-scale systems that are products of modem technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

Modeling and simulation of charged particle beam transport in the UTA 2 meter Time of Flight Positron Annihilation Induced Auger Spectrometer

NASA Astrophysics Data System (ADS)

Joglekar, Prasad; Lim, Lawrence; Kalaskar, Sushant; Shastry, Karthik; Satyal, Suman; Weiss, Alexander

2010-10-01

Time of Flight Positron Annihilation Induced Auger Electron Spectroscopy (TOF PAES) is a surface analytical technique with high surface selectivity. Almost 95% of the PAES signal originates from the sample's topmost layer due to the trapping of positrons just above the surface in an image-potential well before annihilation. This talk presents a description of the TOF technique as the results of modeling of the charged particle transport used in the design of the 2 meter TOF-PAES system currently under construction at UTA.

Monitoring microbial responses to ocean deoxygenation in a model oxygen minimum zone.

PubMed

Hallam, Steven J; Torres-Beltrán, Mónica; Hawley, Alyse K

2017-10-31

Today in Scientific Data, two compendia of geochemical and multi-omic sequence information (DNA, RNA, protein) generated over almost a decade of time series monitoring in a seasonally anoxic coastal marine setting are presented to the scientific community. These data descriptors introduce a model ecosystem for the study of microbial responses to ocean deoxygenation, a phenotype that is currently expanding due to climate change. Public access to this time series information is intended to promote scientific collaborations and the generation of new hypotheses relevant to microbial ecology, biogeochemistry and global change issues.

The effects of nuclear magnetic resonance on patients with cardiac pacemakers

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

Pavlicek, W.; Geisinger, M.; Castle, L.

1983-04-01

The effect of nuclear magnetic resonance (NMR) imaging on six representative cardiac pacemakers was studied. The results indicate that the threshold for initiating the asynchronous mode of a pacemaker is 17 gauss. Radiofrequency levels are present in an NMR unit and may confuse or possibly inhibit demand pacemakers, although sensing circuitry is normally provided with electromagnetic interference discrimination. Time-varying magnetic fields can generate pulse amplitudes and frequencies to mimic cardiac activity. A serious limitation in the possibility of imaging a patient with a pacemaker would be the alteration of normal pulsing parameters due to time-varying magnetic fields.

Algorithms for elasto-plastic-creep postbuckling

NASA Technical Reports Server (NTRS)

Padovan, J.; Tovichakchaikul, S.

1984-01-01

This paper considers the development of an improved constrained time stepping scheme which can efficiently and stably handle the pre-post-buckling behavior of general structure subject to high temperature environments. Due to the generality of the scheme, the combined influence of elastic-plastic behavior can be handled in addition to time dependent creep effects. This includes structural problems exhibiting indefinite tangent properties. To illustrate the capability of the procedure, several benchmark problems employing finite element analyses are presented. These demonstrate the numerical efficiency and stability of the scheme. Additionally, the potential influence of complex creep histories on the buckling characteristics is considered.

Long-term stormwater quantity and quality analysis using continuous measurements in a French urban catchment.

PubMed

Sun, Siao; Barraud, Sylvie; Castebrunet, Hélène; Aubin, Jean-Baptiste; Marmonier, Pierre

2015-11-15

The assessment of urban stormwater quantity and quality is important for evaluating and controlling the impact of the stormwater to natural water and environment. This study mainly addresses long-term evolution of stormwater quantity and quality in a French urban catchment using continuous measured data from 2004 to 2011. Storm event-based data series are obtained (716 rainfall events and 521 runoff events are available) from measured continuous time series. The Mann-Kendall test is applied to these event-based data series for trend detection. A lack of trend is found in rainfall and an increasing trend in runoff is detected. As a result, an increasing trend is present in the runoff coefficient, likely due to growing imperviousness of the catchment caused by urbanization. The event mean concentration of the total suspended solid (TSS) in stormwater does not present a trend, whereas the event load of TSS has an increasing tendency, which is attributed to the increasing event runoff volume. Uncertainty analysis suggests that the major uncertainty in trend detection results lies in uncertainty due to available data. A lack of events due to missing data leads to dramatically increased uncertainty in trend detection results. In contrast, measurement uncertainty in time series data plays a trivial role. The intra-event distribution of TSS is studied based on both M(V) curves and pollutant concentrations of absolute runoff volumes. The trend detection test reveals no significant change in intra-event distributions of TSS in the studied catchment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Change in general relativistic precession rates due to Lidov-Kozai oscillations in Solar system

NASA Astrophysics Data System (ADS)

Sekhar, A.; Asher, D. J.; Werner, S. C.; Vaubaillon, J.; Li, G.

2017-06-01

Both general relativistic (GR) precession and the Lidov-Kozai mechanism, separately, are known to play an important role in the orbital evolution of Solar system bodies. Previous works have studied these two mechanisms independently in great detail. However, both these phenomena occurring at the same time in real Solar system bodies have rarely been explored. In this work, we find a continuum connecting the GR precession dominant and Lidov-Kozai-like mechanism dominant regimes, I.e. an intermediate regime where the competing effects of GR precession and Lidov-Kozai-like oscillations coexist simultaneously. We find some real examples in the Solar system in this intermediate regime. Moreover, we identify a rare example among them, comet 96P/Machholz 1, which shows significant changes in the rates of GR precession (an order of magnitude higher than Mercury's GR precession rate) due to sungrazing and sun-colliding phases induced by Lidov-Kozai-like oscillations. This comet's combination of orbital elements and initial conditions (at the present epoch) favour this measurable rapid change in GR precession (at some points peaking up to 60 times Mercury's GR precession rate) along with prograde-retrograde inclination flip (due to Lidov-Kozai-like oscillations). Similar tests are performed for hundreds of bodies lying in the moderately low perihelion distance and moderately low semimajor axis phase space in the Solar system, the present lowest perihelion distance asteroid 322P/SOHO 1, and further examples connected with 96P/Machholz 1 namely, the Marsden and Kracht families of sungrazing comets plus low perihelion meteoroid streams like Daytime Arietids and Southern Delta Aquariids.

X-ray induced luminescence properties of (Y,Eu)AlO3 single crystals

NASA Astrophysics Data System (ADS)

Kuro, Tomoaki; Nakauchi, Daisuke; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

2017-02-01

We investigated photoluminescence, scintillation and dosimeter properties of (Y1-x Eux)AlO3 (x = 0.001, 0.5 and 1) single crystals (hereafter denoted as Eu:YAP for x = 0.001, EYAP for x = 0.5 and EAP for x = 1). The samples were prepared by the Floating Zone method. In photoluminescence (PL), we observed a broad emission around 300-400 nm due to host under excitation of 280 nm, and emissions due to the 4f state transitions of Eu3+ appeared around 590 nm and 615 nm. Scintillation spectra also show emission peaks around 590 and 615 nm due to the 4f state transitions of Eu3+ in all the samples. In addition, emissions around 300-400 nm due to YAP host and around 550-700 nm due to 5d-4f transitions of Eu2+ appeared in Eu:YAP. The PL and scintillation decay time profiles consisted of several exponential decay components. The fast (ns) component group was possibly due to host emission, and especially Eu:YAP demonstrated a very fast PL decay time of 16 ns. The intermediate (μs) component group was due to the 5d-4f transitions of Eu2+. The slow (ms) component group was ascribed to the 4f state transitions of Eu3+ ion. The Eu:YAP sample showed intense thermally-stimulated luminescence (TSL) with peaks at 46, 155, 255 and 443 °C. The intensity was much higher than those of EAP and EYAP. In particular, the peak at 254 °C, which showed the highest intensity, was due to doping with Eu. The TSL dose response function showed a good linearity (R2 > 0.99) over a wide dose range from 0.1 mGy to 100 mGy for Eu:YAP, which showed the highest sensitivity among the present samples.

Staphylococci in Competition1

PubMed Central

Peterson, A. C.; Black, J. J.; Gunderson, M. F.

1962-01-01

In studies carried on in bacteriological media with selected cultures, definite repressive effects were noted on the growth of the Staphylococcus population by a mixture of saprophytic, psychrophilic bacterial species. This repressive effect became more pronounced as the relative proportion of the bacterial population which was staphylococcal became smaller. A varied saprophytic bacterial flora of some numbers apparently would offer definite protection to foods through repression of staphylococcal growth and by rendering the food inedible before the rise of appreciable numbers of staphylococci. It would appear that at the optimal temperature for staphylococcal growth, staphylococci could multiply rapidly in the mixed population due to the comparative shortness of the generation time of this species and because of the lengthened lag phase of the saprophytic bacterial species at this elevated temperature, especially when only cultures having psychrophilic characteristics were present. This temperature is substantially above that encountered in practical experience. With the passage of time, the staphylococcal population was completely overgrown by the saprohytes present. This effect might be eliminated in the presence of psychrophilic and mesophilic, saprophytic species. The repressive effect of competition by saprophytic, psychrophilic organisms is extremely effective up to room temperature on the staphylococcal population. Even when significant staphylococcal populations were achieved in the artificial media, such tremendous numbers of saprophytes were obtained either earlier or at the same time so that a frozen food containing this population would be organoleptically unacceptable due to the degradative action of enzymes from the saprophytic psychrophile population. PMID:14485778

Digitalizing historical high resolution water level data: Challenges and opportunities

NASA Astrophysics Data System (ADS)

Holinde, Lars; Hein, Hartmut; Barjenbruch, Ulrich

2017-04-01

Historical tide-gauge data offer the opportunities for determining variations in key characteristics for water level data and the analyses of past extreme events (storm surges). These information are important for calculating future trends and scenarios. But there are challenges involved due to the extensive effort needed to digitalize gauge sheets and quality control the resulting historical data. Based on these conditions, two main sources for inaccuracies in historical time series can be identified. First are several challenges due to the digitalization of the historical data, e.g. general quality of the sheets, multiple crossing lines of the observed water levels and additional comments on the sheet describing problems or additional information during the measurements. Second are problems during the measurements themselves. These can include the incorrect positioning of the sheets, trouble with the tide-gauge and maintenance. Errors resulting from these problems can be e.g. flat lines, discontinuities and outlier. Especially, the characterization of outliers has to be conducted carefully, to distinguish between real outliers and the appearance of extreme events. Methods for the quality control process involve the use of statistics, machine learning and neural networks. These will be described and applied to three different time series from tide gauge stations at the cost of Lower Saxony, Germany. Resulting difficulties and outcomes of the quality control process will be presented and explained. Furthermore, we will present a first glance at analyses for these time series.

Comparison between Euler and quaternion parametrization in UAV dynamics

NASA Astrophysics Data System (ADS)

Alaimo, A.; Artale, V.; Milazzo, C.; Ricciardello, A.

2013-10-01

The main topic addressed in this paper is a comparison between Euler parametrization and Quaternion one in the description of the dynamics of a Unmanned Aerial Vehicle assumed as a rigid body. In details Newton Euler equations are re-written in terms of quaternions due to the singularities that the Euler angles lead. This formulation not only avoids the gimbal lock but also allows a better performance in numerical implementation thanks to the linearity of quaternion algebra. This kind of analysis, proved by some numerical results presented, has a great importance due to the applicability of quaternion to drone control. Indeed, this latter requires a time response as quick as possible, in order to be reliable.

Merge measuring mesh for complex surface parts

NASA Astrophysics Data System (ADS)

Ye, Jianhua; Gao, Chenghui; Zeng, Shoujin; Xu, Mingsan

2018-04-01

Due to most parts self-occlude and limitation of scanner range, it is difficult to scan the entire part by one time. For modeling of part, multi measuring meshes need to be merged. In this paper, a new merge method is presented. At first, using the grid voxelization method to eliminate the most of non-overlap regions, and retrieval overlap triangles method by the topology of mesh is proposed due to its ability to improve the efficiency. Then, to remove the large deviation of overlap triangles, deleting by overlap distance is discussion. After that, this paper puts forward a new method of merger meshes by registration and combination mesh boundary point. Through experimental analysis, the suggested methods are effective.

Bioheat model evaluations of laser effects on tissues: role of water evaporation and diffusion

NASA Astrophysics Data System (ADS)

Nagulapally, Deepthi; Joshi, Ravi P.; Thomas, Robert J.

2011-03-01

A two-dimensional, time-dependent bioheat model is applied to evaluate changes in temperature and water content in tissues subjected to laser irradiation. Our approach takes account of liquid-to-vapor phase changes and a simple diffusive flow of water within the biotissue. An energy balance equation considers blood perfusion, metabolic heat generation, laser absorption, and water evaporation. The model also accounts for the water dependence of tissue properties (both thermal and optical), and variations in blood perfusion rates based on local tissue injury. Our calculations show that water diffusion would reduce the local temperature increases and hot spots in comparison to simple models that ignore the role of water in the overall thermal and mass transport. Also, the reduced suppression of perfusion rates due to tissue heating and damage with water diffusion affect the necrotic depth. Two-dimensional results for the dynamic temperature, water content, and damage distributions will be presented for skin simulations. It is argued that reduction in temperature gradients due to water diffusion would mitigate local refractive index variations, and hence influence the phenomenon of thermal lensing. Finally, simple quantitative evaluations of pressure increases within the tissue due to laser absorption are presented.

Intrinsic errors in transporting a single-spin qubit through a double quantum dot

NASA Astrophysics Data System (ADS)

Li, Xiao; Barnes, Edwin; Kestner, J. P.; Das Sarma, S.

2017-07-01

Coherent spatial transport or shuttling of a single electron spin through semiconductor nanostructures is an important ingredient in many spintronic and quantum computing applications. In this work we analyze the possible errors in solid-state quantum computation due to leakage in transporting a single-spin qubit through a semiconductor double quantum dot. In particular, we consider three possible sources of leakage errors associated with such transport: finite ramping times, spin-dependent tunneling rates between quantum dots induced by finite spin-orbit couplings, and the presence of multiple valley states. In each case we present quantitative estimates of the leakage errors, and discuss how they can be minimized. The emphasis of this work is on how to deal with the errors intrinsic to the ideal semiconductor structure, such as leakage due to spin-orbit couplings, rather than on errors due to defects or noise sources. In particular, we show that in order to minimize leakage errors induced by spin-dependent tunnelings, it is necessary to apply pulses to perform certain carefully designed spin rotations. We further develop a formalism that allows one to systematically derive constraints on the pulse shapes and present a few examples to highlight the advantage of such an approach.

QC-ART: A tool for real-time quality control assessment of mass spectrometry-based proteomics data.

PubMed

Stanfill, Bryan A; Nakayasu, Ernesto S; Bramer, Lisa M; Thompson, Allison M; Ansong, Charles K; Clauss, Therese; Gritsenko, Marina A; Monroe, Matthew E; Moore, Ronald J; Orton, Daniel J; Piehowski, Paul D; Schepmoes, Athena A; Smith, Richard D; Webb-Robertson, Bobbie-Jo; Metz, Thomas O

2018-04-17

Liquid chromatography-mass spectrometry (LC-MS)-based proteomics studies of large sample cohorts can easily require from months to years to complete. Acquiring consistent, high-quality data in such large-scale studies is challenging because of normal variations in instrumentation performance over time, as well as artifacts introduced by the samples themselves, such as those due to collection, storage and processing. Existing quality control methods for proteomics data primarily focus on post-hoc analysis to remove low-quality data that would degrade downstream statistics; they are not designed to evaluate the data in near real-time, which would allow for interventions as soon as deviations in data quality are detected.  In addition to flagging analyses that demonstrate outlier behavior, evaluating how the data structure changes over time can aide in understanding typical instrument performance or identify issues such as a degradation in data quality due to the need for instrument cleaning and/or re-calibration.  To address this gap for proteomics, we developed Quality Control Analysis in Real-Time (QC-ART), a tool for evaluating data as they are acquired in order to dynamically flag potential issues with instrument performance or sample quality.  QC-ART has similar accuracy as standard post-hoc analysis methods with the additional benefit of real-time analysis.  We demonstrate the utility and performance of QC-ART in identifying deviations in data quality due to both instrument and sample issues in near real-time for LC-MS-based plasma proteomics analyses of a sample subset of The Environmental Determinants of Diabetes in the Young cohort. We also present a case where QC-ART facilitated the identification of oxidative modifications, which are often underappreciated in proteomic experiments. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Chemistry resolved kinetic flow modeling of TATB based explosives

NASA Astrophysics Data System (ADS)

Vitello, Peter; Fried, Laurence E.; William, Howard; Levesque, George; Souers, P. Clark

2012-03-01

Detonation waves in insensitive, TATB-based explosives are believed to have multiple time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. We use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. We term our model chemistry resolved kinetic flow, since CHEETAH tracks the time dependent concentrations of individual species in the detonation wave and calculates EOS values based on the concentrations. We present here two variants of our new rate model and comparison with hot, ambient, and cold experimental data for PBX 9502.

Time-Dependent Behavior of Reinforced Polymer Concrete Columns under Eccentric Axial Loading

PubMed Central

Berardi, Valentino Paolo; Mancusi, Geminiano

2012-01-01

Polymer concretes (PCs) represent a promising alternative to traditional cementitious materials in the field of new construction. In fact, PCs exhibit high compressive strength and ultimate compressive strain values, as well as good chemical resistance. Within the context of these benefits, this paper presents a study on the time-dependent behavior of polymer concrete columns reinforced with different bar types using a mechanical model recently developed by the authors. Balanced internal reinforcements are considered (i.e., two bars at both the top and bottom of the cross-section). The investigation highlights relevant stress and strain variations over time and, consequently, the emergence of a significant decrease in concrete’s stiffness and strength over time. Therefore, the results indicate that deferred effects due to viscous flow may significantly affect the reliability of reinforced polymer concrete elements over time.

Acral peeling skin syndrome in two East-African siblings: case report

PubMed Central

2012-01-01

Background Acral peeling skin syndrome is a rare autosomal recessive genodermatosis due to a missense mutation in transglutaminase 5. The skin peeling occurs at the separation of the stratum corneum from the stratum granulosum. Case presentation We present a case of two siblings who developed continuous peeling of the palms and soles from the first year of life. This peeling was more severe on the soles than palms and on younger sibling than elder sibling. Peeling is worsened by occlusion and sweating. Conclusions Sporadic cases of Acral Peeling Skin Syndrome occur in African population. There is variability in time of presentation and clinical severity even within families. PMID:22429841

Patch dynamics of a foraging assemblage of bees.

PubMed

Wright, David Hamilton

1985-03-01

The composition and dynamics of foraging assemblages of bees were examined from the standpoint of species-level arrival and departure processes in patches of flowers. Experiments with bees visiting 4 different species of flowers in subalpine meadows in Colorado gave the following results: 1) In enriched patches the rates of departure of bees were reduced, resulting in increases in both the number of bees per species and the average number of species present. 2) The reduction in bee departure rates from enriched patches was due to mechanical factors-increased flower handling time, and to behavioral factors-an increase in the number of flowers visited per inflorescence and in the number of inflorescences visited per patch. Bees foraging in enriched patches could collect nectar 30-45% faster than those foraging in control patches. 3) The quantitative changes in foraging assemblages due to enrichment, in terms of means and variances of species population sizes, fraction of time a species was present in a patch, and in mean and variance of the number of species present, were in reasonable agreement with predictions drawn from queuing theory and studies in island biogeography. 4) Experiments performed with 2 species of flowers with different corolla tube lengths demonstrated that manipulation of resources of differing availability had unequal effects on particular subsets of the larger foraging community. The arrival-departure process of bees on flowers and the immigration-extinction process of species on islands are contrasted, and the value of the stochastic, species-level approach to community composition is briefly discussed.

Path-space variational inference for non-equilibrium coarse-grained systems

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

Harmandaris, Vagelis, E-mail: harman@uoc.gr; Institute of Applied and Computational Mathematics; Kalligiannaki, Evangelia, E-mail: ekalligian@tem.uoc.gr

In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirelymore » data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.« less

A High Speed Finger-Print Optical Scanning Method

DTIC Science & Technology

2000-01-01

biometrics technologies for authentication, from the view point of convenience and higher security, dactyloscopy is by far the best, much better than the...sensing technologies using static capacitance, thermal or optical detection, the optical detection is by far with the most potential to meet the...present time due to the low resolution of the inherent nature of thermal imaging technique. Besides, this method is easily influenced by environmental

3rd Workshop on Semantic Ambient Media Experience (SAME) - In Conjunction with AmI-2010

NASA Astrophysics Data System (ADS)

Lugmayr, Artur; Stockleben, Bjoern; Kaario, Juha; Pogorelc, Bogdan; Risse, Thomas

The SAME workshop takes place for the 3rd time in 2010, and it's theme in this year was creating the business value-creation, vision, media theories and technology for ambient media. SAME differs from other workshops due to its interactive and creative touch and going beyond simple powerpoint presentations. Several results will be published by AMEA - the AMbient Media Association (www.ambientmediaassociation.org.

Cardiac tamponade due to umbilical venous catheter in the new born

PubMed Central

Abdellatif, Mohamed; Ahmed, Ashfag; Alsenaidi, Khalfan

2012-01-01

With more and more extreme premature and very low-birth weight babies being resuscitated, umbilical central venous catheterisation is now being used more frequently in neonatal intensive care. The authors present a case of cardiac tamponade following umbilical venous catheterisation in a neonate, an uncommon, yet potentially fatal complication. The patient was diagnosed at the appropriate time by echocardiography and urgent pericardiocentesis proved lifesaving. PMID:22802560

Current Trends in Metric Conversion in the United States: Potential Trouble for National Defense.

DTIC Science & Technology

1980-05-01

measures in the United States appears inevitable, but is being prolonged due to present legisla- *tion which allows each industrial sector to convert...centralized government planning and leadership toward metrication in the shortest possible time. II. Problem: Spurred by the automotive industry , voluntary...conversion among major U.S. industries is snowballing while public resistance to met- rication is stiffening. This confrontation threatens to

Ocean Variability Effects on Underwater Acoustic Communications

DTIC Science & Technology

2007-09-30

sea surface was rougher. To recover the transmitted symbols which have been passed through the time-varying multi-path acoustic channels, a new ...B is about 6 dB higher than that during enviromental case A. Due to the large aperture and deployment range of the MPL array, the channel impulse...environmental fluctuations and the performance of coherent underwater acoustic communications presents new insights into the operational effectiveness of

High Performance Polymer Memory and Its Formation

DTIC Science & Technology

2007-04-26

the retention time of the device was performed to estimate the barrier height of the charge trap . The activation energy was approximated to be about...characteristics and presented a model to explain the mechanism of electrical switching in the device. By exploiting an electric-field induced charge transfer...electrical current in the high conductivity state would be due to some temperature-independent charge tunneling processes. The IV curves could be

Improving Cognitive Skills of the Industrial Robot

NASA Astrophysics Data System (ADS)

Bezák, Pavol

2015-08-01

At present, there are plenty of industrial robots that are programmed to do the same repetitive task all the time. Industrial robots doing such kind of job are not able to understand whether the action is correct, effective or good. Object detection, manipulation and grasping is challenging due to the hand and object modeling uncertainties, unknown contact type and object stiffness properties. In this paper, the proposal of an intelligent humanoid hand object detection and grasping model is presented assuming that the object properties are known. The control is simulated in the Matlab Simulink/ SimMechanics, Neural Network Toolbox and Computer Vision System Toolbox.

The method of projected characteristics for the evolution of magnetic arches

NASA Technical Reports Server (NTRS)

Nakagawa, Y.; Hu, Y. Q.; Wu, S. T.

1987-01-01

A numerical method of solving fully nonlinear MHD equation is described. In particular, the formulation based on the newly developed method of projected characteristics (Nakagawa, 1981) suitable to study the evolution of magnetic arches due to motions of their foot-points is presented. The final formulation is given in the form of difference equations; therefore, the analysis of numerical stability is also presented. Further, the most important derivation of physically self-consistent, time-dependent boundary conditions (i.e. the evolving boundary equations) is given in detail, and some results obtained with such boundary equations are reported.

Absorption, fluorescence and second harmonic generation in Cr3+-doped BiB3O6 glasses

NASA Astrophysics Data System (ADS)

Kuznik, W.; Fuks-Janczarek, I.; Wojciechowski, A.; Kityk, I. V.; Kiisk, V.; Majchrowski, A.; Jaroszewicz, L. R.; Brik, M. G.; Nagy, G. U. L.

2015-06-01

Synthesis, spectral properties and photoinduced nonlinear optical effects of chromium-doped BiB3O6 glass are studied in the present paper. Absorption, excitation and time resolved luminescence spectra are presented and luminescence decay behavior is discussed. Detailed analysis of the obtained spectra (assignment of the most prominent spectral features in terms of the corresponding Cr3+ energy levels, crystal field strength Dq, Racah parameters B and C) was performed. A weak photostimulated second harmonic generation signal was found to increase drastically due to poling by proton implantation in the investigated sample.

IRTF observations of the occultation of 28 Sgr by Saturn

NASA Technical Reports Server (NTRS)

Harrington, Joseph; Cooke, Maren L.; Forrest, William J.; Pipher, Judith L.; Dunham, Edward W.; Elliot, J. L.

1993-01-01

NASA's Mauna Kea IR Telescope Facility obtained an IR-imaging time series for the July 3, 1989 occultation of 28 Sgr by Saturn and its rings; the stellar signal is present in these images throughout the ring occultation event. These data are noted to vary systematically with respect to the Voyager data over large radius scales, perhaps due to stellar signal diffraction through the rings. The stellar diameter, which is projected to be about 20 km, placed most bending- and density-wave trains below measurable resolution. Masses and mean optical depths are presented for individual ring sections.

Switch configuration for migration to optical fiber network

NASA Technical Reports Server (NTRS)

Zobrist, George W.

1993-01-01

The purpose is to investigate the migration of an Ethernet LAN segment to fiber optics. At the present time it is proposed to support a Fiber Distributed Data Interface (FDDI) backbone and to upgrade the VAX cluster to fiber optic interface. Possibly some workstations will have an FDDI interface. The remaining stations on the Ethernet LAN will be segmented. The rationale for migrating from the present Ethernet configuration to a fiber optic backbone is due to the increase in the number of workstations and the movement of applications to a windowing environment, extensive document transfers, and compute intensive applications.

Demonstration of Time Domain Multiplexed Readout for Magnetically Coupled Calorimeters

NASA Technical Reports Server (NTRS)

Porst, J.-P.; Adams, J. S.; Balvin, M.; Bandler, S.; Beyer, J.; Busch, S. E.; Drung, D.; Seidel, G. M.; Smith, S. J.; Stevenson, T. R.

2012-01-01

Magnetically coupled calorimeters (MCC) have extremely high potential for x-ray applications due to the inherent high energy resolution capability and being non-dissipative. Although very high energy-resolution has been demonstrated, until now there has been no demonstration of multiplexed read-out. We report on the first realization of a time domain multiplexed (TDM) read-out. While this has many similarities with TDM of transition-edge-sensors (TES), for MGGs the energy resolution is limited by the SQUID read-out noise and requires the well established scheme to be altered in order to minimize degradation due to noise aliasing effects. In cur approach, each pixel is read out by a single first stage SQUID (SQ1) that is operated in open loop. The outputs of the SQ1 s are low-pass filtered with an array of low cross-talk inductors, then fed into a single-stage SQUID TD multiplexer. The multiplexer is addressed from room temperature and read out through a single amplifier channel. We present results achieved with a new detector platform. Noise performance is presented and compared to expectations. We have demonstrated multiplexed X-ray spectroscopy at 5.9keV with delta_FWHM=10eV. In an optimized setup, we show it is possible to multiplex 32 detectors without significantly degrading the Intrinsic detector resolution.

Caution: Precision Error in Blade Alignment Results in Faulty Unsteady CFD Simulation

NASA Astrophysics Data System (ADS)

Lewis, Bryan; Cimbala, John; Wouden, Alex

2012-11-01

Turbomachinery components experience unsteady loads at several frequencies. The rotor frequency corresponds to the time for one rotor blade to rotate between two stator vanes, and is normally dominant for rotor torque oscillations. The guide vane frequency corresponds to the time for two rotor blades to pass by one guide vane. The machine frequency corresponds to the machine RPM. Oscillations at the machine frequency are always present due to minor blade misalignments and imperfections resulting from manufacturing defects. However, machine frequency oscillations should not be present in CFD simulations if the mesh is free of both blade misalignment and surface imperfections. The flow through a Francis hydroturbine was modeled with unsteady Reynolds-Averaged Navier-Stokes (URANS) CFD simulations and a dynamic rotating grid. Spectral analysis of the unsteady torque on the rotor blades revealed a large component at the machine frequency. Close examination showed that one blade was displaced by 0 .0001° due to round-off errors during mesh generation. A second mesh without blade misalignment was then created. Subsequently, large machine frequency oscillations were not observed for this mesh. These results highlight the effect of minor geometry imperfections on CFD solutions. This research was supported by a grant from the DoE and a National Defense Science and Engineering Graduate Fellowship.

Zonification of Areas Susceptible to Slope Instability in the State of Colima, Mexico

NASA Astrophysics Data System (ADS)

Ramirez-Ruiz, J. J.

2015-12-01

The Topography of the State of Colima in combination with the tectonic and geographic situation originates vulnerability to the slope instability in the Occidental part of Mexico. This problematic increase in rain Season ( May to November) due to the presence of hurricanes that can produce a great precipitations in a short time period. Likewise the seismicity present in this area due to the tectonic interaction of the tectonic plates (Cocos subducting to the Northamerica) contribute to increase this phenomenology. Here we present the results of zonification using a methodology to estimate the susceptibility areas and a procedure to estimate the probability of occurrent of this phenomena originated by precipitation and seismicity. By zonification of areas we consider topographic, morphologic and geologic factors to determine the category of the areas. . For the risk we consider the Susceptibiliy, Precipitation and Seismicity as will be described here. We consider the Precipitation return period of 2, 5, 10, 50 and 100 years to estimate the risk of slope instability in the State of Colima. We observe that risk increase on this area considering the precipitation return periods of 25, 50 and 100 years and it will be accelerated by the occurrence of seismicity specially by magnitude great than 7 as it occurs at least one time each 5 years.

Ubiquitous health monitoring and real-time cardiac arrhythmias detection: a case study.

PubMed

Li, Jian; Zhou, Haiying; Zuo, Decheng; Hou, Kun-Mean; De Vaulx, Christophe

2014-01-01

As the symptoms and signs of heart diseases that cause sudden cardiac death, cardiac arrhythmia has attracted great attention. Due to limitations in time and space, traditional approaches to cardiac arrhythmias detection fail to provide a real-time continuous monitoring and testing service applicable in different environmental conditions. Integrated with the latest technologies in ECG (electrocardiograph) analysis and medical care, the pervasive computing technology makes possible the ubiquitous cardiac care services, and thus brings about new technical challenges, especially in the formation of cardiac care architecture and realization of the real-time automatic ECG detection algorithm dedicated to care devices. In this paper, a ubiquitous cardiac care prototype system is presented with its architecture framework well elaborated. This prototype system has been tested and evaluated in all the clinical-/home-/outdoor-care modes with a satisfactory performance in providing real-time continuous cardiac arrhythmias monitoring service unlimitedly adaptable in time and space.

The string soundscape at gravitational wave detectors

NASA Astrophysics Data System (ADS)

Garcia Garcia, Isabel; Krippendorf, Sven; March-Russell, John

2018-04-01

We argue that gravitational wave signals due to collisions of ultra-relativistic bubble walls may be common in string theory. This occurs due to a process of post-inflationary vacuum decay via quantum tunnelling. Though we study a specific string construction involving warped throats, we argue that our conclusions are more general. Many such transitions could have occurred in the post-inflationary Universe, as a large number of throats with exponentially different mass scales can be present in the string landscape, leading to several signals of widely different frequencies - a soundscape connected to the landscape of vacua. Detectors such as aLIGO/VIRGO, LISA, and pulsar timing observations with SKA and EPTA have the sensitivity to detect such signals. A distribution of primordial black holes is also a likely consequence, though reliable estimates of masses and their abundance require dedicated numerical simulations, as do the fine details of the gravitational wave spectrum due to the unusual nature of the transition.

Rolling Shutter Effect aberration compensation in Digital Holographic Microscopy

NASA Astrophysics Data System (ADS)

Monaldi, Andrea C.; Romero, Gladis G.; Cabrera, Carlos M.; Blanc, Adriana V.; Alanís, Elvio E.

2016-05-01

Due to the sequential-readout nature of most CMOS sensors, each row of the sensor array is exposed at a different time, resulting in the so-called rolling shutter effect that induces geometric distortion to the image if the video camera or the object moves during image acquisition. Particularly in digital holograms recording, while the sensor captures progressively each row of the hologram, interferometric fringes can oscillate due to external vibrations and/or noises even when the object under study remains motionless. The sensor records each hologram row in different instants of these disturbances. As a final effect, phase information is corrupted, distorting the reconstructed holograms quality. We present a fast and simple method for compensating this effect based on image processing tools. The method is exemplified by holograms of microscopic biological static objects. Results encourage incorporating CMOS sensors over CCD in Digital Holographic Microscopy due to a better resolution and less expensive benefits.

The potential offered by real-time, high-sensitivity monitoring of ethane in breath and some pilot studies using optical spectroscopy

NASA Astrophysics Data System (ADS)

Skeldon, Kenneth D.; Patterson, Claire; Wyse, Cathy A.; Gibson, Graham M.; Padgett, Miles J.; Longbottom, Chris; McMillan, Lesley C.

2005-06-01

Breath analysis applied to biomedical applications has gained much momentum is recent years due to the growing research demonstrating that breath gas can provide clinically useful data. Particularly exciting is the area of real-time breath analysis which, when coupled with appropriately chosen target species, can offer a novel method for non-invasive patient monitoring. Here we describe the role of ethane, a breath gas of universal appeal in assessing in vivo oxidative stress (cell damage). We first present a review of emerging applications where real-time ethane monitoring could yield original new results for healthcare. We then report on results from a portable ethane spectroscopy system (accuracy better then 100 parts per trillion (1 part in 1010) over a 1 s time response) that we have developed to exploit some of these applications. By presenting some initial results from pilot studies in the life sciences, we comment on the requirements that the next stage of optical spectroscopy technology has to meet in order to benefit clinical end-users.

A preamplification approach to GMO detection in processed foods.

PubMed

Del Gaudio, S; Cirillo, A; Di Bernardo, G; Galderisi, U; Cipollaro, M

2010-03-01

DNA is widely used as a target for GMO analysis because of its stability and high detectability. Real-time PCR is the method routinely used in most analytical laboratories due to its quantitative performance and great sensitivity. Accurate DNA detection and quantification is dependent on the specificity and sensitivity of the amplification protocol as well as on the quality and quantity of the DNA used in the PCR reaction. In order to enhance the sensitivity of real-time PCR and consequently expand the number of analyzable target genes, we applied a preamplification technique to processed foods where DNA can be present in low amounts and/or in degraded forms thereby affecting the reliability of qualitative and quantitative results. The preamplification procedure utilizes a pool of primers targeting genes of interest and is followed by real-time PCR reactions specific for each gene. An improvement of Ct values was found comparing preamplified vs. non-preamplified DNA. The strategy reported in the present study will be also applicable to other fields requiring quantitative DNA testing by real-time PCR.

Bin recycling strategy for improving the histogram precision on GPU

NASA Astrophysics Data System (ADS)

Cárdenas-Montes, Miguel; Rodríguez-Vázquez, Juan José; Vega-Rodríguez, Miguel A.

2016-07-01

Histogram is an easily comprehensible way to present data and analyses. In the current scientific context with access to large volumes of data, the processing time for building histogram has dramatically increased. For this reason, parallel construction is necessary to alleviate the impact of the processing time in the analysis activities. In this scenario, GPU computing is becoming widely used for reducing until affordable levels the processing time of histogram construction. Associated to the increment of the processing time, the implementations are stressed on the bin-count accuracy. Accuracy aspects due to the particularities of the implementations are not usually taken into consideration when building histogram with very large data sets. In this work, a bin recycling strategy to create an accuracy-aware implementation for building histogram on GPU is presented. In order to evaluate the approach, this strategy was applied to the computation of the three-point angular correlation function, which is a relevant function in Cosmology for the study of the Large Scale Structure of Universe. As a consequence of the study a high-accuracy implementation for histogram construction on GPU is proposed.

Immunization Route Dictates Cross-Priming Efficiency and Impacts the Optimal Timing of Adjuvant Delivery

PubMed Central

Bouvier, Isabelle; Jusforgues-Saklani, Hélène; Lim, Annick; Lemaître, Fabrice; Lemercier, Brigitte; Auriau, Charlotte; Nicola, Marie-Anne; Leroy, Sandrine; Law, Helen K.; Bandeira, Antonio; Moon, James J.; Bousso, Philippe; Albert, Matthew L.

2011-01-01

Delivery of cell-associated antigen represents an important strategy for vaccination. While many experimental models have been developed in order to define the critical parameters for efficient cross-priming, few have utilized quantitative methods that permit the study of the endogenous repertoire. Comparing different strategies of immunization, we report that local delivery of cell-associated antigen results in delayed T cell cross-priming due to the increased time required for antigen capture and presentation. In comparison, delivery of disseminated antigen resulted in rapid T cell priming. Surprisingly, local injection of cell-associated antigen, while slower, resulted in the differentiation of a more robust, polyfunctional, effector response. We also evaluated the combination of cell-associated antigen with poly I:C delivery and observed an immunization route-specific effect regarding the optimal timing of innate immune stimulation. These studies highlight the importance of considering the timing and persistence of antigen presentation, and suggest that intradermal injection with delayed adjuvant delivery is the optimal strategy for achieving CD8+ T cell cross-priming. PMID:22566860

A practical approach for predicting retention time shifts due to pressure and temperature gradients in ultra-high-pressure liquid chromatography.

PubMed

Åsberg, Dennis; Chutkowski, Marcin; Leśko, Marek; Samuelsson, Jörgen; Kaczmarski, Krzysztof; Fornstedt, Torgny

2017-01-06

Large pressure gradients are generated in ultra-high-pressure liquid chromatography (UHPLC) using sub-2μm particles causing significant temperature gradients over the column due to viscous heating. These pressure and temperature gradients affect retention and ultimately result in important selectivity shifts. In this study, we developed an approach for predicting the retention time shifts due to these gradients. The approach is presented as a step-by-step procedure and it is based on empirical linear relationships describing how retention varies as a function of temperature and pressure and how the average column temperature increases with the flow rate. It requires only four experiments on standard equipment, is based on straightforward calculations, and is therefore easy to use in method development. The approach was rigorously validated against experimental data obtained with a quality control method for the active pharmaceutical ingredient omeprazole. The accuracy of retention time predictions was very good with relative errors always less than 1% and in many cases around 0.5% (n=32). Selectivity shifts observed between omeprazole and the related impurities when changing the flow rate could also be accurately predicted resulting in good estimates of the resolution between critical peak pairs. The approximations which the presented approach are based on were all justified. The retention factor as a function of pressure and temperature was studied in an experimental design while the temperature distribution in the column was obtained by solving the fundamental heat and mass balance equations for the different experimental conditions. We strongly believe that this approach is sufficiently accurate and experimentally feasible for this separation to be a valuable tool when developing a UHPLC method. After further validation with other separation systems, it could become a useful approach in UHPLC method development, especially in the pharmaceutical industry where demands are high for robustness and regulatory oversight. Copyright © 2016 Elsevier B.V. All rights reserved.

Symmetry in circularly polarized molecular high-order harmonic generation with intense bicircular laser pulses

NASA Astrophysics Data System (ADS)

Yuan, Kai-Jun; Bandrauk, André D.

2018-02-01

We present symmetry effects of laser fields and molecular geometries in circularly polarized high-order harmonic generation by bichromatic counter-rotating circularly polarized laser pulses. Simulations are performed on oriented molecules by numerically solving time-dependent Schrödinger equations. We discuss how electron recollision trajectories by the orthogonal laser field polarizations influence the harmonic polarization by using a time-frequency analysis of harmonics. It is found that orientation-dependent asymmetric ionization in linear molecules due to Coulomb potentials gives rise to a dependence of the polarization on the harmonic frequency. Effects of Coriolis forces are also presented on harmonic generation. Electron recollision trajectories illustrate the effects of the relative symmetry of the field and the molecule, thus paving a method for circularly polarized attosecond pulse generation and molecular orbital imaging in more complex systems.

Repeated CMV Infection in a Heart Transplantation Patient

PubMed Central

Melero-Ferrer, Josep; Sanchez-Lazaro, Ignacio J.; Navea-Tejerina, Amparo; Almenar-Bonet, Luis; Blanes-Julia, Marino; Martinez-Dolz, Luis; Salvador-Sanz, Antonio

2012-01-01

Infections are one of the leading causes of morbidity and mortality in heart transplantation (HTx). Cytomegalovirus (CMV) is the most common viral infection during the first year after HTx, but it is more unusual after this time. We present the case of a patient who underwent an HTx due to a severe ischemic heart disease. Although the patient did not have a high risk for CMV, infection, he suffered a reactivation during the first year and then up to six more episodes, especially in his eyes. The patient received different treatments against CMV and the immunosuppression was changed several times. Finally, everolimus was introduced instead of cyclosporine, and mycophenolate mofetil was withdrawn. The presented case provides an example of how the immunosupresion plays a key role in some infections in spite of being a suitable antiviral treatment. PMID:23213610

Results from the JPL IGS Analysis Center IGS14 Reprocessing Campaign

NASA Astrophysics Data System (ADS)

Ries, P. A.; Amiri, N.; Heflin, M. B.; Sakumura, C.; Sibois, A. E.; Sibthorpe, A.; David, M. W.

2017-12-01

The JPL IGS analysis center has begun a campaign to reprocess GPS orbits and clocks in the IGS14 reference frame. Though the new frame is only a few millimeters offset from the previous IGb08 frame, a reprocessing is required for consistent use of the new frame due to a change in the satellite phase center offsets between the frames. We will present results on the reprocessing campaign from 2002 to present in order to evaluate any effects caused by the new frame. We also create long-term time-series and periodograms of translation, rotation, and scale parameters to see if there is any divergence between the frames. We will also process long-term PPP time series and derived velocities for a well-distributed set of stations in each frame to compare with the published frame offsets.

Measurement of neoclassically predicted edge current density at ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Dunne, M. G.; McCarthy, P. J.; Wolfrum, E.; Fischer, R.; Giannone, L.; Burckhart, A.; the ASDEX Upgrade Team

2012-12-01

Experimental confirmation of neoclassically predicted edge current density in an ELMy H-mode plasma is presented. Current density analysis using the CLISTE equilibrium code is outlined and the rationale for accuracy of the reconstructions is explained. Sample profiles and time traces from analysis of data at ASDEX Upgrade are presented. A high time resolution is possible due to the use of an ELM-synchronization technique. Additionally, the flux-surface-averaged current density is calculated using a neoclassical approach. Results from these two separate methods are then compared and are found to validate the theoretical formula. Finally, several discharges are compared as part of a fuelling study, showing that the size and width of the edge current density peak at the low-field side can be explained by the electron density and temperature drives and their respective collisionality modifications.

Flight Departure Delay and Rerouting Under Uncertainty in En Route Convective Weather

NASA Technical Reports Server (NTRS)

Mukherjee, Avijit; Grabbe, Shon; Sridhar, Banavar

2011-01-01

Delays caused by uncertainty in weather forecasts can be reduced by improving traffic flow management decisions. This paper presents a methodology for traffic flow management under uncertainty in convective weather forecasts. An algorithm for assigning departure delays and reroutes to aircraft is presented. Departure delay and route assignment are executed at multiple stages, during which, updated weather forecasts and flight schedules are used. At each stage, weather forecasts up to a certain look-ahead time are treated as deterministic and flight scheduling is done to mitigate the impact of weather on four-dimensional flight trajectories. Uncertainty in weather forecasts during departure scheduling results in tactical airborne holding of flights. The amount of airborne holding depends on the accuracy of forecasts as well as the look-ahead time included in the departure scheduling. The weather forecast look-ahead time is varied systematically within the experiments performed in this paper to analyze its effect on flight delays. Based on the results, longer look-ahead times cause higher departure delays and additional flying time due to reroutes. However, the amount of airborne holding necessary to prevent weather incursions reduces when the forecast look-ahead times are higher. For the chosen day of traffic and weather, setting the look-ahead time to 90 minutes yields the lowest total delay cost.

Cycle-time determination and process control of sequencing batch membrane bioreactors.

PubMed

Krampe, J

2013-01-01

In this paper a method to determine the cycle time for sequencing batch membrane bioreactors (SBMBRs) is introduced. One of the advantages of SBMBRs is the simplicity of adapting them to varying wastewater composition. The benefit of this flexibility can only be fully utilised if the cycle times are optimised for the specific inlet load conditions. This requires either proactive and ongoing operator adjustment or active predictive instrument-based control. Determination of the cycle times for conventional sequencing batch reactor (SBR) plants is usually based on experience. Due to the higher mixed liquor suspended solids concentrations in SBMBRs and the limited experience with their application, a new approach to calculate the cycle time had to be developed. Based on results from a semi-technical pilot plant, the paper presents an approach for calculating the cycle time in relation to the influent concentration according to the Activated Sludge Model No. 1 and the German HSG (Hochschulgruppe) Approach. The approach presented in this paper considers the increased solid contents in the reactor and the resultant shortened reaction times. This allows for an exact calculation of the nitrification and denitrification cycles with a tolerance of only a few minutes. Ultimately the same approach can be used for a predictive control strategy and for conventional SBR plants.

Self-adjusting threshold mechanism for pixel detectors

NASA Astrophysics Data System (ADS)

Heim, Timon; Garcia-Sciveres, Maurice

2017-09-01

Readout chips of hybrid pixel detectors use a low power amplifier and threshold discrimination to process charge deposited in semiconductor sensors. Due to transistor mismatch each pixel circuit needs to be calibrated individually to achieve response uniformity. Traditionally this is addressed by programmable threshold trimming in each pixel, but requires robustness against radiation effects, temperature, and time. In this paper a self-adjusting threshold mechanism is presented, which corrects the threshold for both spatial inequality and time variation and maintains a constant response. It exploits the electrical noise as relative measure for the threshold and automatically adjust the threshold of each pixel to always achieve a uniform frequency of noise hits. A digital implementation of the method in the form of an up/down counter and combinatorial logic filter is presented. The behavior of this circuit has been simulated to evaluate its performance and compare it to traditional calibration results. The simulation results show that this mechanism can perform equally well, but eliminates instability over time and is immune to single event upsets.

Cross-visit tumor sub-segmentation and registration with outlier rejection for dynamic contrast-enhanced MRI time series data.

PubMed

Buonaccorsi, G A; Rose, C J; O'Connor, J P B; Roberts, C; Watson, Y; Jackson, A; Jayson, G C; Parker, G J M

2010-01-01

Clinical trials of anti-angiogenic and vascular-disrupting agents often use biomarkers derived from DCE-MRI, typically reporting whole-tumor summary statistics and so overlooking spatial parameter variations caused by tissue heterogeneity. We present a data-driven segmentation method comprising tracer-kinetic model-driven registration for motion correction, conversion from MR signal intensity to contrast agent concentration for cross-visit normalization, iterative principal components analysis for imputation of missing data and dimensionality reduction, and statistical outlier detection using the minimum covariance determinant to obtain a robust Mahalanobis distance. After applying these techniques we cluster in the principal components space using k-means. We present results from a clinical trial of a VEGF inhibitor, using time-series data selected because of problems due to motion and outlier time series. We obtained spatially-contiguous clusters that map to regions with distinct microvascular characteristics. This methodology has the potential to uncover localized effects in trials using DCE-MRI-based biomarkers.

Atmospheric carbon dioxide and chlorofluoromethanes - Combined effects on stratospheric ozone, temperature, and surface temperature

NASA Technical Reports Server (NTRS)

Callis, L. B.; Natarajan, M.

1981-01-01

The effects of combined CO2 and CFCl3 and CF2Cl2 time-dependent scenarios on atmospheric O3 and temperature are described; the steady-state levels of O3 and surface temperature, to which the chlorofluoromethane scenario tends in the presence of twice and four time ambient CO2, are examined; and surface temperature changes, caused by the combined effects, are established. A description of the model and of the experiments is presented. Results indicate that (1) the total ozone time history is significantly different from that due to the chlorofluoromethane alone; (2) a local ozone minimum occurs in the upper stratosphere about 45 years from the present with a subsequent ozone increase, then decline; and (3) steady-state solutions indicate that tropospheric temperature and water vapor increases, associated with increased infrared opacity, cause significant changes in tropospheric ozone levels for 2 x CO2 and 4 x CO2, without the addition of chlorofluoromethanes.

Combined Optimal Control System for excavator electric drive

NASA Astrophysics Data System (ADS)

Kurochkin, N. S.; Kochetkov, V. P.; Platonova, E. V.; Glushkin, E. Y.; Dulesov, A. S.

2018-03-01

The article presents a synthesis of the combined optimal control algorithms of the AC drive rotation mechanism of the excavator. Synthesis of algorithms consists in the regulation of external coordinates - based on the theory of optimal systems and correction of the internal coordinates electric drive using the method "technical optimum". The research shows the advantage of optimal combined control systems for the electric rotary drive over classical systems of subordinate regulation. The paper presents a method for selecting the optimality criterion of coefficients to find the intersection of the range of permissible values of the coordinates of the control object. There is possibility of system settings by choosing the optimality criterion coefficients, which allows one to select the required characteristics of the drive: the dynamic moment (M) and the time of the transient process (tpp). Due to the use of combined optimal control systems, it was possible to significantly reduce the maximum value of the dynamic moment (M) and at the same time - reduce the transient time (tpp).

Investigation and appreciation of optimal output feedback. Volume 1: A convergent algorithm for the stochastic infinite-time discrete optimal output feedback problem

NASA Technical Reports Server (NTRS)

Halyo, N.; Broussard, J. R.

1984-01-01

The stochastic, infinite time, discrete output feedback problem for time invariant linear systems is examined. Two sets of sufficient conditions for the existence of a stable, globally optimal solution are presented. An expression for the total change in the cost function due to a change in the feedback gain is obtained. This expression is used to show that a sequence of gains can be obtained by an algorithm, so that the corresponding cost sequence is monotonically decreasing and the corresponding sequence of the cost gradient converges to zero. The algorithm is guaranteed to obtain a critical point of the cost function. The computational steps necessary to implement the algorithm on a computer are presented. The results are applied to a digital outer loop flight control problem. The numerical results for this 13th order problem indicate a rate of convergence considerably faster than two other algorithms used for comparison.

Observations of volcanic plumes using small balloon soundings

NASA Astrophysics Data System (ADS)

Voemel, H.

2015-12-01

Eruptions of volcanoes are very difficult to predict and for practical purposes may occur at any time. Any observing system intending to observe volcanic eruptions has to be ready at any time. Due to transport time scales, emissions of large volcanic eruptions, in particular injections into the stratosphere, may be detected at locations far from the volcano within days to weeks after the eruption. These emissions may be observed using small balloon soundings at dedicated sites. Here we present observations of particles of the Icelandic Grimsvotn eruption at the Meteorological Observatory Lindenberg, Germany in the months following the eruption and observations of opportunity of other volcanic particle events. We also present observations of the emissions of SO2 from the Turrialba volcano at San Jose, Costa Rica. We argue that dedicated sites for routine observations of the clean and perturbed atmosphere using small sounding balloons are an important element in the detection and quantification of emissions from future volcanic eruptions.

Discrete-time stability of continuous-time controller designs for large space structures

NASA Technical Reports Server (NTRS)

Balas, M. J.

1982-01-01

In most of the stable control designs for flexible structures, continuous time is assumed. However, in view of the implementation of the controllers by on-line digital computers, the discrete-time stability of such controllers is an important consideration. In the case of direct-velocity feedback (DVFB), involving negative feedback from collocated force actuators and velocity sensors, it is not immediately apparent how much delay due to digital implementation of DVFB can be tolerated without loss of stability. The present investigation is concerned with such questions. A study is conducted of the discrete-time stability of DVFB, taking into account an employment of Euler's method of approximation of the time derivative. The obtained result gives an indication of the acceptable time-step size for stable digital implementation of DVFB. A result derived in connection with the consideration of the discrete-time stability of stable continuous-time systems provides a general condition under which digital implementation of such a system will remain stable.

Methods for building an inexpensive computer-controlled olfactometer for temporally precise experiments

PubMed Central

Lundström, Johan N.; Gordon, Amy R.; Alden, Eva C.; Boesveldt, Sanne; Albrecht, Jessica

2010-01-01

Many human olfactory experiments call for fast and stable stimulus-rise times as well as exact and stable stimulus-onset times. Due to these temporal demands, an olfactometer is often needed. However, an olfactometer is a piece of equipment that either comes with a high price tag or requires a high degree of technical expertise to build and/or to run. Here, we detail the construction of an olfactometer that is constructed almost exclusively with “off-the-shelf” parts, requires little technical knowledge to build, has relatively low price tags, and is controlled by E-Prime, a turnkey-ready and easily-programmable software commonly used in psychological experiments. The olfactometer can present either solid or liquid odor sources, and it exhibits a fast stimulus-rise time and a fast and stable stimulus-onset time. We provide a detailed description of the olfactometer construction, a list of its individual parts and prices, as well as potential modifications to the design. In addition, we present odor onset and concentration curves as measured with a photoionization detector, together with corresponding GC/MS analyses of signal-intensity drop (5.9%) over a longer period of use. Finally, we present data from behavioral and psychophysiological recordings demonstrating that the olfactometer is suitable for use during event-related EEG experiments. PMID:20688109

Real-time ultrasonic weld evaluation system

NASA Astrophysics Data System (ADS)

Katragadda, Gopichand; Nair, Satish; Liu, Harry; Brown, Lawrence M.

1996-11-01

Ultrasonic testing techniques are currently used as an alternative to radiography for detecting, classifying,and sizing weld defects, and for evaluating weld quality. Typically, ultrasonic weld inspections are performed manually, which require significant operator expertise and time. Thus, in recent years, the emphasis is to develop automated methods to aid or replace operators in critical weld inspections where inspection time, reliability, and operator safety are major issues. During this period, significant advances wee made in the areas of weld defect classification and sizing. Very few of these methods, however have found their way into the market, largely due to the lack of an integrated approach enabling real-time implementation. Also, not much research effort was directed in improving weld acceptance criteria. This paper presents an integrated system utilizing state-of-the-art techniques for a complete automation of the weld inspection procedure. The modules discussed include transducer tracking, classification, sizing, and weld acceptance criteria. Transducer tracking was studied by experimentally evaluating sonic and optical position tracking techniques. Details for this evaluation are presented. Classification is obtained using a multi-layer perceptron. Results from different feature extraction schemes, including a new method based on a combination of time and frequency-domain signal representations are given. Algorithms developed to automate defect registration and sizing are discussed. A fuzzy-logic acceptance criteria for weld acceptance is presented describing how this scheme provides improved robustness compared to the traditional flow-diagram standards.

Single Machine Scheduling and Due Date Assignment with Past-Sequence-Dependent Setup Time and Position-Dependent Processing Time

PubMed Central

Zhao, Chuan-Li; Hsu, Hua-Feng

2014-01-01

This paper considers single machine scheduling and due date assignment with setup time. The setup time is proportional to the length of the already processed jobs; that is, the setup time is past-sequence-dependent (p-s-d). It is assumed that a job's processing time depends on its position in a sequence. The objective functions include total earliness, the weighted number of tardy jobs, and the cost of due date assignment. We analyze these problems with two different due date assignment methods. We first consider the model with job-dependent position effects. For each case, by converting the problem to a series of assignment problems, we proved that the problems can be solved in O(n 4) time. For the model with job-independent position effects, we proved that the problems can be solved in O(n 3) time by providing a dynamic programming algorithm. PMID:25258727

Single machine scheduling and due date assignment with past-sequence-dependent setup time and position-dependent processing time.

PubMed

Zhao, Chuan-Li; Hsu, Chou-Jung; Hsu, Hua-Feng

2014-01-01

This paper considers single machine scheduling and due date assignment with setup time. The setup time is proportional to the length of the already processed jobs; that is, the setup time is past-sequence-dependent (p-s-d). It is assumed that a job's processing time depends on its position in a sequence. The objective functions include total earliness, the weighted number of tardy jobs, and the cost of due date assignment. We analyze these problems with two different due date assignment methods. We first consider the model with job-dependent position effects. For each case, by converting the problem to a series of assignment problems, we proved that the problems can be solved in O(n(4)) time. For the model with job-independent position effects, we proved that the problems can be solved in O(n(3)) time by providing a dynamic programming algorithm.

The hard fall effect: high working memory capacity leads to a higher, but less robust short-term memory performance.

PubMed

Thomassin, Noémylle; Gonthier, Corentin; Guerraz, Michel; Roulin, Jean-Luc

2015-01-01

Participants with a high working memory span tend to perform better than low spans in a variety of tasks. However, their performance is paradoxically more impaired when they have to perform two tasks at once, a phenomenon that could be labeled the "hard fall effect." The present study tested whether this effect exists in a short-term memory task, and investigated the proposal that the effect is due to high spans using efficient facilitative strategies under simple task conditions. Ninety-eight participants performed a spatial short-term memory task under simple and dual task conditions; stimuli presentation times either allowed for the use of complex facilitative strategies or not. High spans outperformed low spans only under simple task conditions when presentation times allowed for the use of facilitative strategies. These results indicate that the hard fall effect exists on a short-term memory task and may be caused by individual differences in strategy use.

Micromechanics of transformation fields in ageing linear viscoelastic composites: effects of phase dissolution or precipitation

NASA Astrophysics Data System (ADS)

Honorio, Tulio

2017-11-01

Transformation fields, in an affine formulation characterizing mechanical behavior, describe a variety of physical phenomena regardless their origin. Different composites, notably geomaterials, present a viscoelastic behavior, which is, in some cases of industrial interest, ageing, i.e. it evolves independently with respect to time and loading time. Here, a general formulation of the micromechanics of prestressed or prestrained composites in Ageing Linear Viscoelasticity (ALV) is presented. Emphasis is put on the estimation of effective transformation fields in ALV. The result generalizes Ageing Linear Thermo- and Poro-Viscoelasticity and it can be used in approaches coping with a phase transformation. Additionally, the results are extended to the case of locally transforming materials due to non-coupled dissolution and/or precipitation of a given (elastic or viscoelastic) phase. The estimations of locally transforming composites can be made with respect to different morphologies. As an application, estimations of the coefficient of thermal expansion of a hydrating alite paste are presented.

Control of Initialized Fractional-Order Systems. Revised

NASA Technical Reports Server (NTRS)

Hartley, Tom T.; Lorenzo, Carl F.

2002-01-01

Due to the importance of historical effects in fractional-order systems, this paper presents a general fractional-order control theory that includes the time-varying initialization response. Previous studies have not properly accounted for these historical effects. The initialization response, along with the forced response, for fractional-order systems is determined. Stability properties of fractional-order systems are presented in the complex w-plane, which is a transformation of the s-plane. Time responses are discussed with respect to pole positions in the complex w-plane and frequency response behavior is included. A fractional-order vector space representation, which is a generalization of the state space concept, is presented including the initialization response. Control methods for vector representations of initialized fractional-order systems are shown. Nyquist, root-locus, and other input-output control methods are adapted to the control of fractional-order systems. Finally, the fractional-order differintegral is generalized to continuous order-distributions that have the possibility of including a continuum of fractional orders in a system element.

Control of Initialized Fractional-Order Systems

NASA Technical Reports Server (NTRS)

Hartly, Tom T.; Lorenzo, Carl F.

2002-01-01

Due to the importance of historical effects in fractional-order systems, this paper presents a general fractional-order control theory that includes the time-varying initialization response. Previous studies have not properly accounted for these historical effects. The initialization response, along with the forced response, for fractional-order systems is determined. Stability properties of fractional-order systems are presented in the complex Airplane, which is a transformation of the s-plane. Time responses are discussed with respect to pole positions in the complex Airplane and frequency response behavior is included. A fractional-order vector space representation, which is a generalization of the state space concept, is presented including the initialization response. Control methods for vector representations of initialized fractional-order systems are shown. Nyquist, root-locus, and other input-output control methods are adapted to the control of fractional-order systems. Finally, the fractional-order differintegral is generalized to continuous order-distributions that have the possibility of including a continuum of fractional orders in a system element.

Influence of oxygen on the chemical stage of radiobiological mechanism

NASA Astrophysics Data System (ADS)

Barilla, Jiří; Lokajíček, Miloš V.; Pisaková, Hana; Simr, Pavel

2016-07-01

The simulation of the chemical stage of radiobiological mechanism may be very helpful in studying the radiobiological effect of ionizing radiation when the water radical clusters formed by the densely ionizing ends of primary or secondary charged particle may form DSBs damaging DNA molecules in living cells. It is possible to study not only the efficiency of individual radicals but also the influence of other species or radiomodifiers (mainly oxygen) being present in water medium during irradiation. The mathematical model based on Continuous Petri nets (proposed by us recently) will be described. It makes it possible to analyze two main processes running at the same time: chemical radical reactions and the diffusion of radical clusters formed during energy transfer. One may study the time change of radical concentrations due to the chemical reactions running during diffusion process. Some orientation results concerning the efficiency of individual radicals in DSB formation (in the case of Co60 radiation) will be presented; the influence of oxygen present in water medium during irradiation will be shown, too.

Studies of planning behavior of aircraft pilots in normal, abnormal, and emergency situations

NASA Technical Reports Server (NTRS)

Johannsen, G.; Rouse, W. B.; Hillmann, K.

1981-01-01

A methodology for the study of human planning behavior in complex dynamic systems is presented and applied to the study of aircraft pilot behavior in normal, abnormal and emergency situations. The method measures the depth of planning, that is the level of detail employed with respect to a specific task, according to responses to a verbal questionnaire, and compares planning depth with variables relating to time, task criticality and the probability of increased task difficulty. In two series of experiments, depth of planning was measured on a five- or ten-point scale during various phases of flight in a HFB-320 simulator under normal flight conditions, abnormal scenarios involving temporary runway closure due to snow removal or temporary CAT-III conditions due to a dense fog, and emergency scenarios involving engine shut-down or hydraulic pressure loss. Results reveal a dichotomy between event-driven and time-driven planning, different effects of automation in abnormal and emergency scenarios and a low correlation between depth of planning and workload or flight performance.

A rare but important adverse effect of tacrolimus in a heart transplant recipient: diabetic ketoacidosis.

PubMed

Öztürk, Zeynelabidin; Gönç, E Nazlı; Akcan, Leman; Kesici, Selman; Ertuğrul, İlker; Bayrakçı, Benan

2015-01-01

Heart transplantation indications in pediatric population include congenital heart diseases, cardiomyopathies and retransplants. Cardiomyopathy is the primary indication for 11 to 17 years of age. The surveillance after transplantation is a very important issue because of both the rejection risk and the adverse effects due to medications after transplantation. Immunosuppressive agents that are commonly used after heart transplantations have several toxicities. Here we present an adolescent patient diagnosed with dilated cardiomyopathy, performed heart transplantation, treated with tacrolimus and suffered from diabetic ketoacidosis due to tacrolimus. After the diagnosis was made the appropriate fluid and insulin therapy was started immediately and ketoacidosis resolved in the first 24 hours of the therapy. The diagnosis revised as new onset diabetes mellitus after transplantation and the tacrolimus dosage titrated to therapeutic level. After glycemic control the patient discharged with rapid acting insulin, three times daily, before meals; and long acting insulin once daily at night. In ten month follow up time the insulin dosages were progressively reduced.

System Validation Experiments for Obtaining Tracer Laser-Induced Fluorescence Data at Elevated Pressure and Temperature.

PubMed

Hartwig, Jason; Mittal, Gaurav; Kumar, Kamal; Sung, Chih-Jen

2018-04-01

This paper presents a set of system validation experiments that can be used to qualify either static or flow experimental systems for gathering tracer photophysical data or conducting laser diagnostics at high pressure and temperature in order to establish design and operation limits and reduce uncertainty in data interpretation. Tests demonstrated here quantify the effect of tracer absorption at the test cell walls, stratification, photolysis, pyrolysis, adequacy of mixing and seeding, and reabsorption of laser light using acetone as the tracer and 282 nm excitation. Results show that acetone exhibits a 10% decrease in fluorescence signal over 36 000 shots at 127.4 mJ/cm 2 , and photolysis is negligible below 1000 shots collected. Meanwhile, appropriately chosen gas residence times can mitigate risks due to pyrolysis and inadequate mixing and seeding; for the current work 100 ms residence time ensured <0.5% alteration of tracer number density due to thermal destruction. Experimental results here are compared to theoretical values from the literature.

Massive star evolution and SN 1987A

NASA Technical Reports Server (NTRS)

Arnett, David

1991-01-01

The evolution of massive stars through hydrogen and helium burning is addressed. A set of stellar evolutionary sequences for mass/solar mass of 15, 20, and 25, and metallicity of 0.002, 0.005, 0.007, 0.010, and 0.20 are presented; semiconvection is restricted to operating slower than the local thermal time scale. Using these sequences, simple models of the massive star content of the LMC are found to agree moderately well with the new observational data of Fitzpatrick and Garmany (1990). LMC supergiants were detected only in their postmain-sequence phases, so that 5-10 times more massive stars are there but not identified as such. It is argued that SN 1987A exhibits the normal evolution of a single star of about 20 solar mases having LMC abundances. Despite the variety of envelope behavior, the structure of the core at collapse is rather similar for the stars of a given mass. Variations due to different rates of mass loss are likely to be larger than those due to composition.

Orbit Determination Accuracy for Comets on Earth-Impacting Trajectories

NASA Technical Reports Server (NTRS)

Kay-Bunnell, Linda

2004-01-01

The results presented show the level of orbit determination accuracy obtainable for long-period comets discovered approximately one year before collision with Earth. Preliminary orbits are determined from simulated observations using Gauss' method. Additional measurements are incorporated to improve the solution through the use of a Kalman filter, and include non-gravitational perturbations due to outgassing. Comparisons between observatories in several different circular heliocentric orbits show that observatories in orbits with radii less than 1 AU result in increased orbit determination accuracy for short tracking durations due to increased parallax per unit time. However, an observatory at 1 AU will perform similarly if the tracking duration is increased, and accuracy is significantly improved if additional observatories are positioned at the Sun-Earth Lagrange points L3, L4, or L5. A single observatory at 1 AU capable of both optical and range measurements yields the highest orbit determination accuracy in the shortest amount of time when compared to other systems of observatories.

Meta-RaPS Algorithm for the Aerial Refueling Scheduling Problem

NASA Technical Reports Server (NTRS)

Kaplan, Sezgin; Arin, Arif; Rabadi, Ghaith

2011-01-01

The Aerial Refueling Scheduling Problem (ARSP) can be defined as determining the refueling completion times for each fighter aircraft (job) on multiple tankers (machines). ARSP assumes that jobs have different release times and due dates, The total weighted tardiness is used to evaluate schedule's quality. Therefore, ARSP can be modeled as a parallel machine scheduling with release limes and due dates to minimize the total weighted tardiness. Since ARSP is NP-hard, it will be more appropriate to develop a pproimate or heuristic algorithm to obtain solutions in reasonable computation limes. In this paper, Meta-Raps-ATC algorithm is implemented to create high quality solutions. Meta-RaPS (Meta-heuristic for Randomized Priority Search) is a recent and promising meta heuristic that is applied by introducing randomness to a construction heuristic. The Apparent Tardiness Rule (ATC), which is a good rule for scheduling problems with tardiness objective, is used to construct initial solutions which are improved by an exchanging operation. Results are presented for generated instances.

Massively parallel algorithms for real-time wavefront control of a dense adaptive optics system

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

Fijany, A.; Milman, M.; Redding, D.

1994-12-31

In this paper massively parallel algorithms and architectures for real-time wavefront control of a dense adaptive optic system (SELENE) are presented. The authors have already shown that the computation of a near optimal control algorithm for SELENE can be reduced to the solution of a discrete Poisson equation on a regular domain. Although, this represents an optimal computation, due the large size of the system and the high sampling rate requirement, the implementation of this control algorithm poses a computationally challenging problem since it demands a sustained computational throughput of the order of 10 GFlops. They develop a novel algorithm,more » designated as Fast Invariant Imbedding algorithm, which offers a massive degree of parallelism with simple communication and synchronization requirements. Due to these features, this algorithm is significantly more efficient than other Fast Poisson Solvers for implementation on massively parallel architectures. The authors also discuss two massively parallel, algorithmically specialized, architectures for low-cost and optimal implementation of the Fast Invariant Imbedding algorithm.« less

Automated acoustic localization and call association for vocalizing humpback whales on the Navy's Pacific Missile Range Facility.

PubMed

Helble, Tyler A; Ierley, Glenn R; D'Spain, Gerald L; Martin, Stephen W

2015-01-01

Time difference of arrival (TDOA) methods for acoustically localizing multiple marine mammals have been applied to recorded data from the Navy's Pacific Missile Range Facility in order to localize and track humpback whales. Modifications to established methods were necessary in order to simultaneously track multiple animals on the range faster than real-time and in a fully automated way, while minimizing the number of incorrect localizations. The resulting algorithms were run with no human intervention at computational speeds faster than the data recording speed on over forty days of acoustic recordings from the range, spanning multiple years. Spatial localizations based on correlating sequences of units originating from within the range produce estimates having a standard deviation typically 10 m or less (due primarily to TDOA measurement errors), and a bias of 20 m or less (due primarily to sound speed mismatch). An automated method for associating units to individual whales is presented, enabling automated humpback song analyses to be performed.

Cannabis: A Neurological Remedy or a Drug of Abuse in India.

PubMed

Biswas, Pronit; Mishra, Pooja; Bose, Devasish; Durgbanshi, Abhilasha

2017-01-01

Since ancient times, the use of cannabis as a medicine is well documented due to its potential therapeutic activity while subsequently its use as drug of abuse spread increasingly. The present review sought to give an insight in the history of medical and recreational use of cannabis in India. Indian use of cannabis dates back to Vedic time, mostly for the ritualistic and religious purposes, as documented in the ancient literature. It was India that introduced the medical use of cannabis to neighboring countries. Nevertheless, in the same India, medical use did not propagate due to religious and social stigma related to the plant itself. The pharmacoactive constituents of cannabis and their therapeutic values in Ayurvetic medicine have been here described together with the adverse effects they can cause with special reference to neurological ones, including withdrawal symptoms. Finally, how cannabis made its route to the Indian society has also been discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Photoinduced proton transfer coupled with energy transfer: Mechanism of sensitized luminescence of terbium ion by salicylic acid doped in polymer.

PubMed

Misra, Vinita; Mishra, Hirdyesh

2008-06-28

In the present work, excited state intramolecular proton transfer (ESIPT) in salicylic acid (SA) monoanion and subsequent sensitization of Tb(3+) ion in polyvinyl alcohol (PVA) have been studied. The study has been carried out both by steady state and time domain fluorescence measurement techniques at room temperature. It is found that the SA completely ionizes and exists as monoanion in PVA. It exhibits a large Stokes shifted blue emission (10 000 cm(-1)) due to ESIPT and shows a decay time of 6.85 ns. On the other hand, Tb(3+) ion shows a very weak green emission and a decay time of approximately 641 mus in PVA film. Upon incorporating Tb(3+) ion in SA doped PVA film, both intensity and decay time of SA decrease and sensitized emission from Tb(+3) ion along with 3.8 mus rise time is observed. Energy transfer is found to take place both from excited singlet as well as triplet states. A brief description of the properties of the present system from the viewpoint of luminescent solar collector material is addressed.

Thermodynamic feature of a Brownian heat engine operating between two heat baths.

PubMed

Asfaw, Mesfin

2014-01-01

A generalized theory of nonequilibrium thermodynamics for a Brownian motor operating between two different heat baths is presented. Via a simple paradigmatic model, we not only explore the thermodynamic feature of the engine in the regime of the nonequilibrium steady state but also study the short time behavior of the system for either the isothermal case with load or, in general, the nonisothermal case with or without load. Many elegant thermodynamic theories can be checked via the present model. Furthermore the dependence of the velocity, the efficiency, and the performance of the refrigerator on time t is examined. Our study reveals a current reversal due to time t. In the early system relaxation period, the model works neither as a heat engine nor as a refrigerator and only after a certain period of time does the model start functioning as a heat engine or as a refrigerator. The performance of the engine also improves with time and at steady state the engine manifests a higher efficiency or performance as a refrigerator. Furthermore the effect of energy exchange via the kinetic energy on the performance of the heat engine is explored.

Demons registration for in vivo and deformable laser scanning confocal endomicroscopy.

PubMed

Chiew, Wei-Ming; Lin, Feng; Seah, Hock Soon

2017-09-01

A critical effect found in noninvasive in vivo endomicroscopic imaging modalities is image distortions due to sporadic movement exhibited by living organisms. In three-dimensional confocal imaging, this effect results in a dataset that is tilted across deeper slices. Apart from that, the sequential flow of the imaging-processing pipeline restricts real-time adjustments due to the unavailability of information obtainable only from subsequent stages. To solve these problems, we propose an approach to render Demons-registered datasets as they are being captured, focusing on the coupling between registration and visualization. To improve the acquisition process, we also propose a real-time visual analytics tool, which complements the imaging pipeline and the Demons registration pipeline with useful visual indicators to provide real-time feedback for immediate adjustments. We highlight the problem of deformation within the visualization pipeline for object-ordered and image-ordered rendering. Visualizations of critical information including registration forces and partial renderings of the captured data are also presented in the analytics system. We demonstrate the advantages of the algorithmic design through experimental results with both synthetically deformed datasets and actual in vivo, time-lapse tissue datasets expressing natural deformations. Remarkably, this algorithm design is for embedded implementation in intelligent biomedical imaging instrumentation with customizable circuitry. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Real-time imaging through strongly scattering media: seeing through turbid media, instantly

PubMed Central

Sudarsanam, Sriram; Mathew, James; Panigrahi, Swapnesh; Fade, Julien; Alouini, Mehdi; Ramachandran, Hema

2016-01-01

Numerous everyday situations like navigation, medical imaging and rescue operations require viewing through optically inhomogeneous media. This is a challenging task as photons propagate predominantly diffusively (rather than ballistically) due to random multiple scattering off the inhomogenieties. Real-time imaging with ballistic light under continuous-wave illumination is even more challenging due to the extremely weak signal, necessitating voluminous data-processing. Here we report imaging through strongly scattering media in real-time and at rates several times the critical flicker frequency of the eye, so that motion is perceived as continuous. Two factors contributed to the speedup of more than three orders of magnitude over conventional techniques - the use of a simplified algorithm enabling processing of data on the fly, and the utilisation of task and data parallelization capabilities of typical desktop computers. The extreme simplicity of the technique, and its implementation with present day low-cost technology promises its utility in a variety of devices in maritime, aerospace, rail and road transport, in medical imaging and defence. It is of equal interest to the common man and adventure sportsperson like hikers, divers, mountaineers, who frequently encounter situations requiring realtime imaging through obscuring media. As a specific example, navigation under poor visibility is examined. PMID:27114106

Quantitative understanding of Forbush decrease drivers based on shock-only and CME-only models using global signature of February 14, 1978 event

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

Raghav, Anil; Lotekar, Ajay; Bhaskar, Ankush

We have studied the Forbush decrease (FD) event that occurred on February 14, 1978 using 43 neutron monitor observatories to understand the global signature of FD. We have studied rigidity dependence of shock amplitude and total FD amplitude. We have found almost the same power law index for both shock phase amplitude and total FD amplitude. Local time variation of shock phase amplitude and maximum depression time of FD have been investigated which indicate possible effect of shock/CME orientation. We have analyzed rigidity dependence of time constants of two phase recovery. Time constants of slow component of recovery phase showmore » rigidity dependence and imply possible effect of diffusion. Solar wind speed was observed to be well correlated with slow component of FD recovery phase. This indicates solar wind speed as possible driver of recovery phase. To investigate the contribution of interplanetary drivers, shock and CME in FD, we have used shock-only and CME-only models. We have applied these models separately to shock phase and main phase amplitudes respectively. This confirms presently accepted physical scenario that the first step of FD is due to propagating shock barrier and second step is due to flux rope of CME/magnetic cloud.« less

Demons registration for in vivo and deformable laser scanning confocal endomicroscopy

NASA Astrophysics Data System (ADS)

Chiew, Wei Ming; Lin, Feng; Seah, Hock Soon

2017-09-01

A critical effect found in noninvasive in vivo endomicroscopic imaging modalities is image distortions due to sporadic movement exhibited by living organisms. In three-dimensional confocal imaging, this effect results in a dataset that is tilted across deeper slices. Apart from that, the sequential flow of the imaging-processing pipeline restricts real-time adjustments due to the unavailability of information obtainable only from subsequent stages. To solve these problems, we propose an approach to render Demons-registered datasets as they are being captured, focusing on the coupling between registration and visualization. To improve the acquisition process, we also propose a real-time visual analytics tool, which complements the imaging pipeline and the Demons registration pipeline with useful visual indicators to provide real-time feedback for immediate adjustments. We highlight the problem of deformation within the visualization pipeline for object-ordered and image-ordered rendering. Visualizations of critical information including registration forces and partial renderings of the captured data are also presented in the analytics system. We demonstrate the advantages of the algorithmic design through experimental results with both synthetically deformed datasets and actual in vivo, time-lapse tissue datasets expressing natural deformations. Remarkably, this algorithm design is for embedded implementation in intelligent biomedical imaging instrumentation with customizable circuitry.

Finite-time sliding surface constrained control for a robot manipulator with an unknown deadzone and disturbance.

PubMed

Ik Han, Seong; Lee, Jangmyung

2016-11-01

This paper presents finite-time sliding mode control (FSMC) with predefined constraints for the tracking error and sliding surface in order to obtain robust positioning of a robot manipulator with input nonlinearity due to an unknown deadzone and external disturbance. An assumed model feedforward FSMC was designed to avoid tedious identification procedures for the manipulator parameters and to obtain a fast response time. Two constraint switching control functions based on the tracking error and finite-time sliding surface were added to the FSMC to guarantee the predefined tracking performance despite the presence of an unknown deadzone and disturbance. The tracking error due to the deadzone and disturbance can be suppressed within the predefined error boundary simply by tuning the gain value of the constraint switching function and without the addition of an extra compensator. Therefore, the designed constraint controller has a simpler structure than conventional transformed error constraint methods and the sliding surface constraint scheme can also indirectly guarantee the tracking error constraint while being more stable than the tracking error constraint control. A simulation and experiment were performed on an articulated robot manipulator to validate the proposed control schemes. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Resonance frequency control of RF normal conducting cavity using gradient estimator of reflected power

NASA Astrophysics Data System (ADS)

Leewe, R.; Shahriari, Z.; Moallem, M.

2017-10-01

Control of the natural resonance frequency of an RF cavity is essential for accelerator structures due to their high cavity sensitivity to internal and external vibrations and the dependency of resonant frequency on temperature changes. Due to the relatively high radio frequencies involved (MHz to GHz), direct measurement of the resonant frequency for real-time control is not possible by using conventional microcontroller hardware. So far, all operational cavities are tuned using phase comparison techniques. The temperature dependent phase measurements render this technique labor and time intensive. To eliminate the phase measurement, reduce man hours and speed up cavity start up time, this paper presents a control theme that relies solely on the reflected power measurement. The control algorithm for the nonlinear system is developed through Lyapunov's method. The controller stabilizes the resonance frequency of the cavity using a nonlinear control algorithm in combination with a gradient estimation method. Experimental results of the proposed system on a test cavity show that the resonance frequency can be tuned to its optimum operating point while the start up time of a single cavity and the accompanied man hours are significantly decreased. A test result of the fully commissioned control system on one of TRIUMF's DTL tanks verifies its performance under real environmental conditions.

Fast packet switching algorithms for dynamic resource control over ATM networks

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

Tsang, R.P.; Keattihananant, P.; Chang, T.

1996-12-01

Real-time continuous media traffic, such as digital video and audio, is expected to comprise a large percentage of the network load on future high speed packet switch networks such as ATM. A major feature which distinguishes high speed networks from traditional slower speed networks is the large amount of data the network must process very quickly. For efficient network usage, traffic control mechanisms are essential. Currently, most mechanisms for traffic control (such as flow control) have centered on the support of Available Bit Rate (ABR), i.e., non real-time, traffic. With regard to ATM, for ABR traffic, two major types ofmore » schemes which have been proposed are rate- control and credit-control schemes. Neither of these schemes are directly applicable to Real-time Variable Bit Rate (VBR) traffic such as continuous media traffic. Traffic control for continuous media traffic is an inherently difficult problem due to the time- sensitive nature of the traffic and its unpredictable burstiness. In this study, we present a scheme which controls traffic by dynamically allocating/de- allocating resources among competing VCs based upon their real-time requirements. This scheme incorporates a form of rate- control, real-time burst-level scheduling and link-link flow control. We show analytically potential performance improvements of our rate- control scheme and present a scheme for buffer dimensioning. We also present simulation results of our schemes and discuss the tradeoffs inherent in maintaining high network utilization and statistically guaranteeing many users` Quality of Service.« less

[Personality disorders--different outlooks and attempts at their integration].

PubMed

Grabski, Bartosz; Gierowski, Józef Krzysztof

2012-01-01

The paper presents different approaches to personality disorders. The authors critically discuss the contemporary categorical psychiatrie (medical) classification and also present psychological approaches with the special attention put to personality trait theories and stemming from them the Five Factor Model (FFM). Due to the coming time of the publication of a new revision of the American classification DSM- 5 the detailed description of the proposals for the new system has been presented. The authors included the most updated version which has just recently been published on the DSM-5 APA web site on 11h June 2011. The proposed changes go forward to the voices of critique of present solutions, and create a hybrid system which will incorporate some elements of the dimensional approach to personality disorders.

Visualizing the quality of partially accruing data for use in decision making

PubMed Central

Eaton, Julia; Painter, Ian; Olson, Don; Lober, William B

2015-01-01

Secondary use of clinical health data for near real-time public health surveillance presents challenges surrounding its utility due to data quality issues. Data used for real-time surveillance must be timely, accurate and complete if it is to be useful; if incomplete data are used for surveillance, understanding the structure of the incompleteness is necessary. Such data are commonly aggregated due to privacy concerns. The Distribute project was a near real-time influenza-like-illness (ILI) surveillance system that relied on aggregated secondary clinical health data. The goal of this work is to disseminate the data quality tools developed to gain insight into the data quality problems associated with these data. These tools apply in general to any system where aggregate data are accrued over time and were created through the end-user-as-developer paradigm. Each tool was developed during the exploratory analysis to gain insight into structural aspects of data quality. Our key finding is that data quality of partially accruing data must be studied in the context of accrual lag—the difference between the time an event occurs and the time data for that event are received, i.e. the time at which data become available to the surveillance system. Our visualization methods therefore revolve around visualizing dimensions of data quality affected by accrual lag, in particular the tradeoff between timeliness and completion, and the effects of accrual lag on accuracy. Accounting for accrual lag in partially accruing data is necessary to avoid misleading or biased conclusions about trends in indicator values and data quality. PMID:27252794

Visualizing the quality of partially accruing data for use in decision making.

PubMed

Eaton, Julia; Painter, Ian; Olson, Don; Lober, William B

2015-01-01

Secondary use of clinical health data for near real-time public health surveillance presents challenges surrounding its utility due to data quality issues. Data used for real-time surveillance must be timely, accurate and complete if it is to be useful; if incomplete data are used for surveillance, understanding the structure of the incompleteness is necessary. Such data are commonly aggregated due to privacy concerns. The Distribute project was a near real-time influenza-like-illness (ILI) surveillance system that relied on aggregated secondary clinical health data. The goal of this work is to disseminate the data quality tools developed to gain insight into the data quality problems associated with these data. These tools apply in general to any system where aggregate data are accrued over time and were created through the end-user-as-developer paradigm. Each tool was developed during the exploratory analysis to gain insight into structural aspects of data quality. Our key finding is that data quality of partially accruing data must be studied in the context of accrual lag-the difference between the time an event occurs and the time data for that event are received, i.e. the time at which data become available to the surveillance system. Our visualization methods therefore revolve around visualizing dimensions of data quality affected by accrual lag, in particular the tradeoff between timeliness and completion, and the effects of accrual lag on accuracy. Accounting for accrual lag in partially accruing data is necessary to avoid misleading or biased conclusions about trends in indicator values and data quality.

Executive Functioning Mediates the Effect of Behavioral Problems on Depression in Mothers of Children With Developmental Disabilities

PubMed Central

Chan, Wai; Smith, Leann E.; Greenberg, Jan S.; Hong, Jinkuk; Mailick, Marsha R.

2017-01-01

The present investigation explored long-term relationships of behavioral symptoms of adolescents and adults with developmental disabilities with the mental health of their mothers. Fragile X premutation carrier mothers of an adolescent or adult child with fragile X syndrome (n = 95), and mothers of a grown child with autism (n = 213) were included. Behavioral symptoms at Time 1 were hypothesized to predict maternal depressive symptoms at Time 3 via maternal executive dysfunction at Time 2. Results provided support for the mediating pathway of executive dysfunction. Additionally, the association of behavioral symptoms with executive dysfunction differed across the two groups, suggesting that premutation carriers may be more susceptible to caregiving stress due to their genotype. PMID:28095060

A method for including external feed in depletion calculations with CRAM and implementation into ORIGEN

DOE PAGES

Isotalo, Aarno E.; Wieselquist, William A.

2015-05-15

A method for including external feed with polynomial time dependence in depletion calculations with the Chebyshev Rational Approximation Method (CRAM) is presented and the implementation of CRAM to the ORIGEN module of the SCALE suite is described. In addition to being able to handle time-dependent feed rates, the new solver also adds the capability to perform adjoint calculations. Results obtained with the new CRAM solver and the original depletion solver of ORIGEN are compared to high precision reference calculations, which shows the new solver to be orders of magnitude more accurate. Lastly, in most cases, the new solver is upmore » to several times faster due to not requiring similar substepping as the original one.« less

Effects of surface roughness, MHD and couple stress on squeeze film characteristics between curved circular plates

NASA Astrophysics Data System (ADS)

Hanumagowda, B. N.; Salma, A.; Nagarajappa, C. S.

2018-04-01

The theoretical discussion is carried out for understanding the combined study of MHD, rough surface and couple-stress in the presence of applied magnetic field between two curved circular plates is present analysis. Modified Reynolds Equations accounting for rough surface using stochastic model of Christensen are mathematically formulated. The close form derivations for pressure, load-supporting capacity and response-film time are obtained. Our results shows that, there is an significant increase (decrease) for pressure, load-supporting capacity and squeeze film time due to the effect of azimuthal (radial) roughness parameter when compared to the Hanumagowda.et.al [14] and numerical data of load supporting capacity and response time are given in Table for engineering applications.

Provable classically intractable sampling with measurement-based computation in constant time

NASA Astrophysics Data System (ADS)

Sanders, Stephen; Miller, Jacob; Miyake, Akimasa

We present a constant-time measurement-based quantum computation (MQC) protocol to perform a classically intractable sampling problem. We sample from the output probability distribution of a subclass of the instantaneous quantum polynomial time circuits introduced by Bremner, Montanaro and Shepherd. In contrast with the usual circuit model, our MQC implementation includes additional randomness due to byproduct operators associated with the computation. Despite this additional randomness we show that our sampling task cannot be efficiently simulated by a classical computer. We extend previous results to verify the quantum supremacy of our sampling protocol efficiently using only single-qubit Pauli measurements. Center for Quantum Information and Control, Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USA.

Evidence for Radiation-Induced Disseminated Intravascular Coagulation as a Major Cause of Radiation-Induced Death in Ferrets

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

Krigsfeld, Gabriel S.; Savage, Alexandria R.; Billings, Paul C.

Purpose: The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Methods and Materials: Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. Results: The lethal dose of radiation to 50% of the population (LD{sub 50}) of the ferrets was established at ∼1.5 Gy, with 100%more » mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Conclusions: Data presented here provide evidence that death at the LD{sub 50} in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals.« less

Evidence for radiation-induced disseminated intravascular coagulation as a major cause of radiation-induced death in ferrets.

PubMed

Krigsfeld, Gabriel S; Savage, Alexandria R; Billings, Paul C; Lin, Liyong; Kennedy, Ann R

2014-03-15

The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. The lethal dose of radiation to 50% of the population (LD50) of the ferrets was established at ∼ 1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Data presented here provide evidence that death at the LD50 in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals. Copyright © 2014 Elsevier Inc. All rights reserved.

How visual timing and form information affect speech and non-speech processing.

PubMed

Kim, Jeesun; Davis, Chris

2014-10-01

Auditory speech processing is facilitated when the talker's face/head movements are seen. This effect is typically explained in terms of visual speech providing form and/or timing information. We determined the effect of both types of information on a speech/non-speech task (non-speech stimuli were spectrally rotated speech). All stimuli were presented paired with the talker's static or moving face. Two types of moving face stimuli were used: full-face versions (both spoken form and timing information available) and modified face versions (only timing information provided by peri-oral motion available). The results showed that the peri-oral timing information facilitated response time for speech and non-speech stimuli compared to a static face. An additional facilitatory effect was found for full-face versions compared to the timing condition; this effect only occurred for speech stimuli. We propose the timing effect was due to cross-modal phase resetting; the form effect to cross-modal priming. Copyright © 2014 Elsevier Inc. All rights reserved.

Long-term hand tele-rehabilitation on the PlayStation 3: benefits and challenges.

PubMed

Burdea, Grigore C; Jain, Abhishek; Rabin, Bryan; Pellosie, Richard; Golomb, Meredith

2011-01-01

Rehabilitation interventions for the hand have shown benefits for children with Hemiplegia due to cerebral palsy or traumatic brain injury. Longer interventions are facilitated if training is provided in the patient's home, due to easier access to care and reduced impact on school or work activities. Providing remote rehabilitation over lengthy periods of time has however its own challenges. This paper presents two pediatric patients with hemiplegia, who practiced virtual hand rehabilitation games using a modified PlayStation 3 and 5DT sensing gloves. Despite severe initial hand spasticity, and occasional technology shortcomings, the subjects practiced for about 14 months, and 6 months, respectively. Game performance data for the second patient is presented. Follow-up evaluations 14 months from the removal of the PlayStation 3 from the home of the child with cerebral palsy showed that the patient had good retention in terms of grasp strength, hand function and bone health. Challenges of long-term home tele-rehabilitation are also discussed.

Report of an unsual case of anophthalmia and craniofacial cleft in a newborn with Toxoplasma gondii congenital infection.

PubMed

Arce-Estrada, Gabriel Emmanuel; Gómez-Toscano, Valeria; Cedillo-Peláez, Carlos; Sesman-Bernal, Ana Luisa; Bosch-Canto, Vanessa; Mayorga-Butrón, José Luis; Vargas-Villavicencio, José Antonio; Correa, Dolores

2017-07-03

We present one unusual case of anophthalmia and craniofacial cleft, probably due to congenital toxoplasmosis only. A two-month-old male had a twin in utero who disappeared between the 7 th and the 14 th week of gestation. At birth, the baby presented anophthalmia and craniofacial cleft, and no sign compatible with genetic or exposition/deficiency problems, like the Wolf-Hirschhorn syndrome or maternal vitamin A deficiency. Congenital toxoplasmosis was confirmed by the presence of IgM abs and IgG neo-antibodies in western blot, as well as by real time PCR in blood. CMV infection was also discarded by PCR and IgM negative results. Structures suggestive of T. gondii pseudocysts were observed in a biopsy taken during the first functional/esthetic surgery. We conclude that this is a rare case of anophthalmia combined with craniofacial cleft due to congenital toxoplasmosis, that must be considered by physicians. This has not been reported before.

Terminal-Area Aircraft Intent Inference Approach Based on Online Trajectory Clustering.

PubMed

Yang, Yang; Zhang, Jun; Cai, Kai-quan

2015-01-01

Terminal-area aircraft intent inference (T-AII) is a prerequisite to detect and avoid potential aircraft conflict in the terminal airspace. T-AII challenges the state-of-the-art AII approaches due to the uncertainties of air traffic situation, in particular due to the undefined flight routes and frequent maneuvers. In this paper, a novel T-AII approach is introduced to address the limitations by solving the problem with two steps that are intent modeling and intent inference. In the modeling step, an online trajectory clustering procedure is designed for recognizing the real-time available routes in replacing of the missed plan routes. In the inference step, we then present a probabilistic T-AII approach based on the multiple flight attributes to improve the inference performance in maneuvering scenarios. The proposed approach is validated with real radar trajectory and flight attributes data of 34 days collected from Chengdu terminal area in China. Preliminary results show the efficacy of the presented approach.

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

NASA Astrophysics Data System (ADS)

Lattime, Scott B.; Steinetz, Bruce M.

2002-09-01

Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed 1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

Turbine Engine Clearance Control Systems: Current Practices and Future Directions

NASA Technical Reports Server (NTRS)

Lattime, Scott B.; Steinetz, Bruce M.

2002-01-01

Improved blade tip sealing in the high pressure compressor (HPC) and high pressure turbine (HPT) can provide dramatic reductions in specific fuel consumption (SFC), time-on-wing, compressor stall margin, and engine efficiency as well as increased payload and mission range capabilities. Maintenance costs to overhaul large commercial gas turbine engines can easily exceed $1M. Engine removal from service is primarily due to spent exhaust gas temperature (EGT) margin caused mainly by the deterioration of HPT components. Increased blade tip clearance is a major factor in hot section component degradation. As engine designs continue to push the performance envelope with fewer parts and the market drives manufacturers to increase service life, the need for advanced sealing continues to grow. A review of aero gas turbine engine HPT performance degradation and the mechanisms that promote these losses are discussed. Benefits to the HPT due to improved clearance management are identified. Past and present sealing technologies are presented along with specifications for next generation engine clearance control systems.

Implementing ADM1 for plant-wide benchmark simulations in Matlab/Simulink.

PubMed

Rosen, C; Vrecko, D; Gernaey, K V; Pons, M N; Jeppsson, U

2006-01-01

The IWA Anaerobic Digestion Model No.1 (ADM1) was presented in 2002 and is expected to represent the state-of-the-art model within this field in the future. Due to its complexity the implementation of the model is not a simple task and several computational aspects need to be considered, in particular if the ADM1 is to be included in dynamic simulations of plant-wide or even integrated systems. In this paper, the experiences gained from a Matlab/Simulink implementation of ADM1 into the extended COST/IWA Benchmark Simulation Model (BSM2) are presented. Aspects related to system stiffness, model interfacing with the ASM family, mass balances, acid-base equilibrium and algebraic solvers for pH and other troublesome state variables, numerical solvers and simulation time are discussed. The main conclusion is that if implemented properly, the ADM1 will also produce high-quality results in dynamic plant-wide simulations including noise, discrete sub-systems, etc. without imposing any major restrictions due to extensive computational efforts.

Congenital Lobar Emphysema: An Approach of Anesthetic Management.

PubMed

Mourya, Meenakshi; Meena, Dharam Singh

2016-08-01

Congenital Lobar Emphysema (CLE) is a medical condition which is quiet rarely seen especially in neonates. The disease is characterized by over inflation of lungs which is produced due to inhibition of escape of inspired air from lungs. This condition usually occurs in infants due to partial obstruction of the bronchus and can be reversed with timely and planned anaesthetic management. Here in, we are presenting a case of an infant who was merely four months of age. CLE was affecting his left upper lobe since birth which was being treated as lobar pneumonia outside at some peripheral health center. The case presented to hospital with the symptoms acute respiratory distress and was taken up for urgent surgical management. Left upper lobectomy was performed which relived his symptoms. Case was discharged from hospital after 10 days of uneventful hospital stay. The case was challenging, as it involved careful and planned anaesthetic management of lung separation as well as prevention of hyperventilation of the un-involved lung.

Acute cervical artery dissection after a dental procedure due to a second inferior molar infection.

PubMed

Delgado, Montserrat G; Riesco, Nuria; Murias, Eduardo; Calleja, Sergio

2015-06-02

Periodontal infections might represent one of the causative factors for cervical artery dissection. We present a case of a 49-year-old woman admitted due to headache. The patient had been suffering from a right second inferior molar infection with a cervical phlegmon for 1 week prior to admission. On 2 October 2014, the patient went to the dentist and a molar extraction was performed in the morning. In the afternoon, the patient began to experience right hemifacial pain that progressed towards an intense and bilateral headache. Neurological status at the time of admission revealed right miosis, ptosis and conjuntival hyperaemia. A CT angiography showed a right internal carotid artery dissection provoking a high-degree stenosis. The relationship between periodontal infection and vascular disease has been previously presented. Microbial agents may directly, and inflammatory and immunological host response indirectly, influence inflammatory changes in cervical arteries favouring dissections with minor traumas. 2015 BMJ Publishing Group Ltd.

Osteoporosis, Fractures, and Diabetes

PubMed Central

2014-01-01

It is well established that osteoporosis and diabetes are prevalent diseases with significant associated morbidity and mortality. Patients with diabetes mellitus have an increased risk of bone fractures. In type 1 diabetes, the risk is increased by ∼6 times and is due to low bone mass. Despite increased bone mineral density (BMD), in patients with type 2 diabetes the risk is increased (which is about twice the risk in the general population) due to the inferior quality of bone. Bone fragility in type 2 diabetes, which is not reflected by bone mineral density, depends on bone quality deterioration rather than bone mass reduction. Thus, surrogate markers and examination methods are needed to replace the insensitivity of BMD in assessing fracture risks of T2DM patients. One of these methods can be trabecular bone score. The aim of the paper is to present the present state of scientific knowledge about the osteoporosis risk in diabetic patient. The review also discusses the possibility of problematic using the study conclusions in real clinical practice. PMID:25050121

Studies Of Infrasonic Propagation Using Dense Seismic Networks

NASA Astrophysics Data System (ADS)

Hedlin, M. A.; deGroot-Hedlin, C. D.; Drob, D. P.

2011-12-01

Although there are approximately 100 infrasonic arrays worldwide, more than ever before, the station density is still insufficient to provide validation for detailed propagation modeling. Relatively large infrasonic signals can be observed on seismic channels due to coupling at the Earth's surface. Recent research, using data from the 70-km spaced 400-station USArray and other seismic network deployments, has shown the value of dense seismic network data for filling in the gaps between infrasonic arrays. The dense sampling of the infrasonic wavefield has allowed us to observe complete travel-time branches of infrasound and address important research problems in infrasonic propagation. We present our analysis of infrasound created by a series of rocket motor detonations that occurred at the UTTR facility in Utah in 2007. These data were well recorded by the USArray seismometers. We use the precisely located blasts to assess the utility of G2S mesoscale models and methods to synthesize infrasonic propagation. We model the travel times of the branches using a ray-based approach and the complete wavefield using a FDTD algorithm. Although results from both rays and FDTD approaches predict the travel times to within several seconds, only about 40% of signals are predicted using rays largely due to penetration of sound into shadow zones. FDTD predicts some sound penetration into the shadow zone, but the observed shadow zones, as defined by the seismic data, have considerably narrower spatial extent than either method predicts, perhaps due to un-modeled small-scale structure in the atmosphere.

Combining Accuracy and Efficiency: An Incremental Focal-Point Method Based on Pair Natural Orbitals.

PubMed

Fiedler, Benjamin; Schmitz, Gunnar; Hättig, Christof; Friedrich, Joachim

2017-12-12

In this work, we present a new pair natural orbitals (PNO)-based incremental scheme to calculate CCSD(T) and CCSD(T0) reaction, interaction, and binding energies. We perform an extensive analysis, which shows small incremental errors similar to previous non-PNO calculations. Furthermore, slight PNO errors are obtained by using T PNO = T TNO with appropriate values of 10 -7 to 10 -8 for reactions and 10 -8 for interaction or binding energies. The combination with the efficient MP2 focal-point approach yields chemical accuracy relative to the complete basis-set (CBS) limit. In this method, small basis sets (cc-pVDZ, def2-TZVP) for the CCSD(T) part are sufficient in case of reactions or interactions, while some larger ones (e.g., (aug)-cc-pVTZ) are necessary for molecular clusters. For these larger basis sets, we show the very high efficiency of our scheme. We obtain not only tremendous decreases of the wall times (i.e., factors >10 2 ) due to the parallelization of the increment calculations as well as of the total times due to the application of PNOs (i.e., compared to the normal incremental scheme) but also smaller total times with respect to the standard PNO method. That way, our new method features a perfect applicability by combining an excellent accuracy with a very high efficiency as well as the accessibility to larger systems due to the separation of the full computation into several small increments.

Management of a Fulminant Upper Gastrointestinal Bleeding Exteriorized Through Hemobilia Due to Arteriobiliary Fistula Between the Common Bile Duct and a Right Hepatic Artery Aneurysm - A Case Report.

PubMed

Bacalbasa, Nicolae; Brezean, Iulian; Anghel, Claudiu; Barbu, Ion; Pautov, Mihai; Balescu, Irina; Brasoveanu, Vladislav

2017-01-01

Right hepatic artery aneurysms are rare events that might remain asymptomatic for a long period of time. However, in cases presenting large lesions, symptoms might develop especially due to the association of compression of the surrounding elements. Most often these symptoms and signs include diffuse abdominal pain, jaundice or portal vein compression signs. In rare cases life-threatening complications might develop due to the aneurysmal erosion of the biliary duct, portal vein or due to the aneurysmal rupture in the peritoneal cavity. In all these cases emergency surgery is imposed. We present the case of a 66-year-old patient diagnosed with a partially thrombosed right hepatic artery aneurysm compressing the common bile duct who was initially submitted to a percutaneous arterial embolization of the aneurysm in association with an external biliary drainage; three weeks later the patient presented a fulminant upper gastrointestinal bleeding exteriorized through the external biliary drainage, hematemesis and hematochezia. The patient was successfully submitted to surgery, intraoperatively a synchronous rupture of the portal vein being revealed. The right hepatic artery aneurysm was resected en bloc with common bile duct resection and segmental portal vein resection. The continuity of the portal vein was re-established through the interposition of a cadaveric allograft, the common bile duct was anastomosed with en Roux en Y limb while the right hepatic artery aneurysm was ligated and resected, the arterial vascularization of the liver being provided by the left hepatic artery. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Studies of Real Roughness Effects for Improved Modeling and Control of Practical Wall-Bounded Turbulent Flows

DTIC Science & Technology

2008-04-22

SUPPLEMENTARY NOTES 14. ABSTRACT The present effort investigates the effects of practical roughness replicated from a turbine blade damaged by deposition of...Motivation Most practical wall-bounded turbulent flows of interest, like flows over turbine blades , through heat exchangers, and over aircraft and ship...significantly roughened over time due to harsh operating conditions. Examples of such conditions include cumulative damage to turbine blades (Bons, 2002

The status of BAT detector

NASA Astrophysics Data System (ADS)

Lien, Amy; Markwardt, Craig B.; Krimm, Hans Albert; Barthelmy, Scott D.; Cenko, Bradley

2018-01-01

We will present the current status of the Swift/BAT detector. In particular, we will report the updated detector gain calibration, the number of enable detectors, and the global bad time intervals with potential calibration issues. We will also summarize the results of the yearly BAT calibration using the Crab nebula. Finally, we will discuss the effects on the BAT survey, such as the sensitivity, localization, and spectral analysis, due to the changes in detector status.

Recent developments related to climate change

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

Lashof, D.A.

1995-12-31

This presentation discusses 8 items that are related to climate change: 1. Berlin mandate calls for emission reduction protocol by 1997; 2. Global temperatures return to record levels in 1994; 3. Shift of timing of seasons detected; 4. Zooplankton declined 80% off the Southern California coast; 5. Disease outbreaks linked to extreme weather; 6. Huge iceberg formed from Antartic ice shelf; 7. Latest model results match temperature record; 8. Stratospheric water vapor increase due to warming.

Radiation-induced extrinsic photoconductivity in Li-doped Si.

NASA Technical Reports Server (NTRS)

Fenimore, E.; Mortka, T.; Corelli, J. C.

1972-01-01

Investigation of the effects of lithium on radiation-produced complexes having long-time stability by examining the localized energy levels in the forbidden gap which give rise to extrinsic photoconductivity. The levels are found to disappear and in some cases shift with annealing in the 100-450 C temperature range. Due to the complexity of the system and the present lack of adequate theory, no complete analysis of the data obtained could be made.

Attentional bias to briefly presented emotional distractors follows a slow time course in visual cortex.

PubMed

Müller, Matthias M; Andersen, Søren K; Hindi Attar, Catherine

2011-11-02

A central controversy in the field of attention is how the brain deals with emotional distractors and to what extent they capture attentional processing resources reflexively due to their inherent significance for guidance of adaptive behavior and survival. Especially, the time course of competitive interactions in early visual areas and whether masking of briefly presented emotional stimuli can inhibit biasing of processing resources in these areas is currently unknown. We recorded frequency-tagged potentials evoked by a flickering target detection task in the foreground of briefly presented emotional or neutral pictures that were followed by a mask in human subjects. We observed greater competition for processing resources in early visual cortical areas with shortly presented emotional relative to neutral pictures ~275 ms after picture offset. This was paralleled by a reduction of target detection rates in trials with emotional pictures ~400 ms after picture offset. Our finding that briefly presented emotional distractors are able to bias attention well after their offset provides evidence for a rather slow feedback or reentrant neural competition mechanism for emotional distractors that continues after the offset of the emotional stimulus.

Real time detection of farm-level swine mycobacteriosis outbreak using time series modeling of the number of condemned intestines in abattoirs.

PubMed

Adachi, Yasumoto; Makita, Kohei

2015-09-01

Mycobacteriosis in swine is a common zoonosis found in abattoirs during meat inspections, and the veterinary authority is expected to inform the producer for corrective actions when an outbreak is detected. The expected value of the number of condemned carcasses due to mycobacteriosis therefore would be a useful threshold to detect an outbreak, and the present study aims to develop such an expected value through time series modeling. The model was developed using eight years of inspection data (2003 to 2010) obtained at 2 abattoirs of the Higashi-Mokoto Meat Inspection Center, Japan. The resulting model was validated by comparing the predicted time-dependent values for the subsequent 2 years with the actual data for 2 years between 2011 and 2012. For the modeling, at first, periodicities were checked using Fast Fourier Transformation, and the ensemble average profiles for weekly periodicities were calculated. An Auto-Regressive Integrated Moving Average (ARIMA) model was fitted to the residual of the ensemble average on the basis of minimum Akaike's information criterion (AIC). The sum of the ARIMA model and the weekly ensemble average was regarded as the time-dependent expected value. During 2011 and 2012, the number of whole or partial condemned carcasses exceeded the 95% confidence interval of the predicted values 20 times. All of these events were associated with the slaughtering of pigs from three producers with the highest rate of condemnation due to mycobacteriosis.

Effects of oxygen concentrations on driver fatigue during simulated driving.

PubMed

Sung, Eun-Jung; Min, Byung-Chan; Kim, Seung-Chul; Kim, Chul-Jung

2005-01-01

Driver fatigue has been the cause of traffic accidents. Despite this, the amount of time that drivers spend within cars has been increasing due to complex city life, traffic congestion, and particular occupational requirements. Consequently, fatigue and stress cannot be avoided. In present study, in order to find out the possibility for reducing fatigue while driving due to the supply of oxygen, driver fatigue resulting from the passage of time when different oxygen concentrations are supplied has been examined through subjective evaluations and reaction times using driving simulator for 10 male subjects. The results revealed the subjective fatigue feeling was highest in the low rate (18%) oxygen condition, while in the high rate (30%), it decreased to a certain extent. The feeling of sleepiness also showed the tendency to decrease somewhat in the case of the driving time having passed over 1h in the high-rate conditions. Also, the reaction time for braking after being instructed to suddenly stop following more than 2h of driving was reduced in the high-rate oxygen conditions compared to the low-rate oxygen condition. From the above results, it was shown that while driving a car, if the oxygen rate is lowered, fatigue is felt severely, and that in the case of supplying a high-rate of oxygen, the feeling of fatigue is lowered to some extent and the reaction time is shortened. It was suggested that the driver's fatigue can be reduced according to the supply of oxygen.

Modeling of growth, evaporation and sedimentation effects on transmission of visible and IR laser beams in artificial fogs

NASA Technical Reports Server (NTRS)

Yue, G. K.; Deepak, A.

1980-01-01

The dense polydisperse aerosol particles in a quiet chamber may spontaneously go through different microphysical processes including gravitational sedimentation, thermal coagulation, and growth or evaporation. In an earlier paper, we presented the results of a parametric study of the combined and separate effects of thermal coagulation and sedimentation on the time dependence of extinction of four visible and IR laser beams traversing an aerosol medium. As a continuation of this series of studies, the separate and combined effects of growth or evaporation and gravitational sedimentation on the time dependence of extinction of the same four visible and IR laser beams traversing in artificial fogs will be reported in this paper. The method of numerically modeling the change of water droplet size distribution with time due to growth/evaporation and the cutoff of larger aerosols due to gravitational sedimentation is described in detail. Factors governing the relative importance of these two processes are discussed. Results of this study show that the relative humidity or ambient temperature is a crucial parameter in determining the optical depth of the water droplet and aerosol media undergoing microphysical processes.

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

Matusik, Katarzyna E.; Duke, Daniel J.; Kastengren, Alan L.

The sparking behavior in an internal combustion engine affects the fuel efficiency, engine-out emissions, and general drivability of a vehicle. As emissions regulations become progressively stringent, combustion strategies, including exhaust gas recirculation (EGR), lean-burn, and turbocharging are receiving increasing attention as models of higher efficiency advanced combustion engines with reduced emissions levels. Because these new strategies affect the working environment of the spark plug, ongoing research strives to understand the influence of external factors on the spark ignition process. Due to the short time and length scales involved and the harsh environment, experimental quantification of the deposited energy from themore » sparking event is difficult to obtain. We present the results of x-ray radiography measurements of spark ignition plasma generated by a conventional spark plug. Our measurements were performed at the 7-BM beamline of the Advanced Photon Source at Argonne National Laboratory. The synchrotron x-ray source enables time-resolved measurements of the density change due to glow discharge in the spark gap with 153 ns temporal and 5 μm spatial resolutions. We also explore the effects of charging time, EGR-relevant gas compositions, and gas pressure on the sparking behavior. We also quantify the influence of the measurement technique on the obtained results.« less

Anthropogenic impact in the Mayan Lowlands of Petén, Guatemala, during the last 5500 years

USGS Publications Warehouse

Battistel, D.; Roman, Marco; Marchetti, A; Kehrwald, Natalie; Radaelli, Marta; Balliana, Eleanora; Toscano, Giuseppina; Barbante, Carlo

2018-01-01

Trace and rare earth elements from a Lake Peten Itzá (Guatemala) sediment core depict the geochemical dynamics affecting the lake from ~5500 y BP to the present. This timing encompasses the Preclassic (4000 to 1700 y BP) and Classic Periods (1700-1000 y BP) when thriving Maya societies extensively cleared land for agriculture. We demonstrate that this land use occurred during times of increased precipitation, where both processes resulted in increased erosion. Rare earth element ratios depict high precipitation rates between 3000 to 1000 y BP, correlating with an increase in allocthonous silicate input and low organic carbon in the “Maya Clay” stratigraphic section, where this layer is ascribed to intensive anthropogenic land use. Cesium anomalies provide additional evidence for runoff due to high rainfalls and amplified by anthropogenic impacts. The Peten Itzá core contains anomalous spikes of arsenic and mercury, where these peaks correspond to documented volcanic eruptions, and therefore are likely due to natural causes. The geochemical composition of sediments and palynological records indicate a re-growth of the forest after ~900 y BP. This increased forest vegetation coincides with the timing of the decline in Maya agriculture.

Epidemiology of urban water distribution systems

NASA Astrophysics Data System (ADS)

Bardet, Jean-Pierre; Little, Richard

2014-08-01

Urban water distribution systems worldwide contain numerous old and fragile pipes that inevitably break, flood streets and damage property, and disrupt economic and social activities. Such breaks often present dramatically in temporal clusters as occurred in Los Angeles during 2009. These clustered pipe breaks share many characteristics with human mortality observed during extreme climatological events such as heat waves or air pollution. Drawing from research and empirical studies in human epidemiology, a framework is introduced to analyze the time variations of disruptive pipe breaks that can help water agencies better understand clustered pipe failures and institute measures to minimize the disruptions caused by them. It is posited that at any time, a cohort of the pipes comprising the water distribution system will be in a weakened state due to fatigue and corrosion. This frail cohort becomes vulnerable during normal operations and ultimately breaks due to rapid increase in crack lengths induced by abnormal stressors. The epidemiological harvesting model developed in this paper simulates an observed time series of monthly pipe breaks and has both explanatory and predictive power. It also demonstrates that models from nonengineering disciplines such as medicine can provide improved insights into the performance of infrastructure systems.

Differential action of medically important Indian BIG FOUR snake venoms on rodent blood coagulation.

PubMed

Hiremath, Vilas; Nanjaraj Urs, A N; Joshi, Vikram; Suvilesh, K N; Savitha, M N; Urs Amog, Prathap; Rudresha, G V; Yariswamy, M; Vishwanath, B S

2016-02-01

Snakebite is a global health problem affecting millions of people. According to WHO, India has the highest mortality and/or morbidity due to snakebite. In spite of commendable research on Indian BIG FOUR venomous species; Naja naja and Bungarus caeruleus (elapid); Daboia russelii and Echis carinatus (viperid), no significant progress has been achieved in terms of diagnosis and management of biting species with appropriate anti-snake venom. Major hurdle is identification of offending species. Present study aims at differentiation of Indian BIG FOUR snake venoms based on their distinguish action on rodent blood coagulation. Assessment of coagulation alterations by elapid venoms showed negligible effect on re-calcification time, prothrombin time, activated partial thromboplastin time and factors assay (I, II, V, VIII and X) both in vitro and in vivo. However, viperid venoms demonstrated significant anticoagulant status due to their remarkable fibrinogen degradation potentials as supported by fibrinogenolytic activity, fibrinogen zymography and rotational thromboelastometry. Though results provide hint on probable alterations of Indian BIG FOUR snake venoms on blood coagulation, the study however needs validation from human victim's samples to ascertain its reliability for identification of biting snake species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Calculations vs. Measurements for Remnant Dose Rates from SNS Spent Structures

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

Popova, Irina I.; Gallmeier, Franz X.; Trotter, Steven M.

The Spallation Neutron Source (SNS) in Oak Ridge, Tennessee, is an accelerator driven neutron scattering facility for materials research. Presently SNS is capable to operate at 1.4 MW proton beam power incident on a mercury target with a proton beam energy of 1 GeV and 60 Hz repetition rate. SNS target system components are periodically replaced because they reach their end-of-life due to radiation induced material damage. Target vessel, which houses mercury target, is exchanged about two-three times per year and the proton beam window (PBW) is exchanged every two – three years.Each spent structure that leaves the SNS sitemore » requires supporting documentation with radionuclide inventory and dose rate prediction for the time of the transportation. Neutronics analyses are performed, assuming realistic irradiation history and decay case to ensure that the container/package, housing the structure, is compliant with the waste management regulations. Analyses are complex due to geometry, multi-code usage and following data treatment.To validate analyses, measurements of dose rates from the spent target vessel # 13 and PBW module #5 were performed. Neutronics analyses were performed to calculate residual dose rates from both structures for the time of measurements.« less

A Two-Timescale Response of the Southern Ocean to Ozone Depletion: Importance of the Background State

NASA Astrophysics Data System (ADS)

Seviour, W.; Waugh, D.; Gnanadesikan, A.

2016-02-01

It has been recently suggested that the response of Southern Ocean sea-ice extent to stratospheric ozone depletion is time-dependent; that the ocean surface initially cools due to enhanced northward Ekman drift caused by a poleward shift in the eddy-driven jet, and then warms after some time due to upwelling of warm waters from below the mixed layer. It is therefore possible that ozone depletion could act to favor a short-term increase in sea-ice extent. However, many uncertainties remain in understanding this mechanism, with different models showing widely differing time-scales and magnitudes of the response. Here, we analyze an ensemble of coupled model simulations with a step-function ozone perturbation. The two-timescale response is present with an approximately 30 year initial cooling period. The response is further shown to be highly dependent upon the background ocean temperature and salinity stratification, which is influenced by both natural internal variability and the isopycnal eddy mixing parameterization. It is suggested that the majority of inter-model differences in the Southern Ocean response to ozone depletion are caused by differences in stratification.

Due-Window Assignment Scheduling with Variable Job Processing Times

PubMed Central

Wu, Yu-Bin

2015-01-01

We consider a common due-window assignment scheduling problem jobs with variable job processing times on a single machine, where the processing time of a job is a function of its position in a sequence (i.e., learning effect) or its starting time (i.e., deteriorating effect). The problem is to determine the optimal due-windows, and the processing sequence simultaneously to minimize a cost function includes earliness, tardiness, the window location, window size, and weighted number of tardy jobs. We prove that the problem can be solved in polynomial time. PMID:25918745

Chemistry Resolved Kinetic Flow Modeling of TATB Based Explosives

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

Vitello, P A; Fried, L E; Howard, W M

2011-07-21

Detonation waves in insensitive, TATB based explosives are believed to have multi-time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. They use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. They term their model chemistry resolved kinetic flow as CHEETAH tracks the time dependent concentrations of individual species in the detonationmore » wave and calculates EOS values based on the concentrations. A HE-validation suite of model simulations compared to experiments at ambient, hot, and cold temperatures has been developed. They present here a new rate model and comparison with experimental data.« less

Neutron star dynamics under time-dependent external torques

NASA Astrophysics Data System (ADS)

Gügercinoǧlu, Erbil; Alpar, M. Ali

2017-11-01

The two-component model describes neutron star dynamics incorporating the response of the superfluid interior. Conventional solutions and applications involve constant external torques, as appropriate for radio pulsars on dynamical time-scales. We present the general solution of two-component dynamics under arbitrary time-dependent external torques, with internal torques that are linear in the rotation rates, or with the extremely non-linear internal torques due to vortex creep. The two-component model incorporating the response of linear or non-linear internal torques can now be applied not only to radio pulsars but also to magnetars and to neutron stars in binary systems, with strong observed variability and noise in the spin-down or spin-up rates. Our results allow the extraction of the time-dependent external torques from the observed spin-down (or spin-up) time series, \\dot{Ω }(t). Applications are discussed.

A time-resolved image sensor for tubeless streak cameras

NASA Astrophysics Data System (ADS)

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

2014-03-01

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