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1

Imaging of short time microscopic scenes with strong light emission: revisited  

NASA Astrophysics Data System (ADS)

In last year's session we presented some experimental results from investigations on microscopic scenes with strong light emission such as exploding wires, for which we used laser based shadow imaging methods. The present paper is understood as a continuation in two branches. First, we'd like to discuss the fourier optical properties of shadow imaging in comparison with the imaging of the object itself and its far field, showing that the shadowgraph is the link between imaging the real object and scatterometry. Second, we present investigations on gathering high dynamic range short images of short time processes using a completely different approach based on luminescent screens, delivering a decaying image of naturally high dynamic range, which - during decay time- might be converted to a series of single images under adapted conditions.

Hahlweg, Cornelius; Zhao, Wenjing; Vogeler, Hendrik; Rothe, Hendrik

2012-10-01

2

Short Communication Revisit on the evolutionary relationship between alternative splicing and  

E-print Network

Short Communication Revisit on the evolutionary relationship between alternative splicing and gene for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai 200433, China b Department duplication Alternative splicing Copy number variation Exon­intron structure Gene duplications and alternative

Gu, Xun

3

Short Selling Regulation after the Financial Crisis – First Principles Revisited  

Microsoft Academic Search

This article examines the recent regulatory developments with regard to short selling. We begin with a comprehensive compilation of emergency restrictions on short selling adopted in the current crisis. Because of the tendency of some regulators to retain certain restrictions permanently, it is important to understand the fundamental legal and economic arguments regarding short selling. These arguments have at their

Seraina GRUENEWALD; Alexander F. WAGNER; Rolf H. WEBER

2010-01-01

4

Revisiting algorithms for generating surrogate time series  

E-print Network

The method of surrogates is one of the key concepts of nonlinear data analysis. Here, we demonstrate that commonly used algorithms for generating surrogates often fail to generate truly linear time series. Rather, they create surrogate realizations with Fourier phase correlations leading to non-detections of nonlinearities. We argue that reliable surrogates can only be generated, if one tests separately for static and dynamic nonlinearities.

C. Raeth; M. Gliozzi; I. E. Papadakis; W. Brinkmann

2011-11-06

5

Time to Revisit the Heterogeneous Telescope Network  

NASA Astrophysics Data System (ADS)

The "Heterogeneous Telescope Network" (HTN) was founded in 2005 as a loose collaboration of people somehow associated with robotic telescopes and/or projects interested in the transient universe. Other than being a very interesting forum for the exchange of ideas, the only lasting contribution of the HTN was a proposed protocol for the operation of a loose e-market for the exchange of telescope time (Allan et al. 2006; White & Allan 2007). Since the last formal meeting in 2007, the HTN has gone into a "Dornröschenschlaf" (a better word than "hibernation") : the players and interest are there, but the public visibility and activity is not. Although the participants knew and know that global networking is the way of the future for many types of science, various things have kept the HTN from taking the idea and actually implementing it: work on simply getting one's own system to work (e.g. myself), career paths of major players (e.g. Allan), dealing with the complexity of ones' own network (TALONS, RoboNet, LCO), and - most importantly - no common science driver big enough to push the participants to try it in earnest. Things have changed, however: robotic telescopes have become easier to create and operate, private networks have matured, large-scale consortia have become more common, event reporting using VOEvent has become the global standard and has a well-defined infrastructure, and large-scale sources of new objects and events are operating or will soon be operating (OGLE, CSS, Pan-STARRs, GAIA). I will review the scientific and sociological prospects for re-invigorating the HTN idea and invite discussion.

Hessman, F. V.

6

Short time information in GPS time series  

NASA Astrophysics Data System (ADS)

This paper presents adjustment's results of the Polish Active Geodetic Network (ASG-EUPOS). ASG-EUPOS is the multifunctional precise satellite positioning system established by the Head Office of Geodesy and Cartography in 2008. It consists of 84 Polish sites with GPS module, 14 Polish sites with GPS/GLONASS module and 20 foreign sites. The adjusted network consisted of over 100 stations, the period covered observations collected from June 2008. The method of adjustment elaborated in the CAG, which is the newest, seventeenth EPN LAC (EPN Local Analysis Centre) established at the end of 2009, is similar with applied in EPN. It is based on the Bernese 5.0 software. The difference to the EPN's solutions lies in the resolution time of adjustment. In the presented research the 1-hour sampling rate with 3-hour windowing is applied. This allows us to make the interpretations concerning short time information in GPS coordinates series. The time span (over 1.5 year) permits the separation between the pure dynamic phenomena (tides) and thermal oscillations in the diurnal and sub-diurnal frequency bands. The presentation contains also the plans for multidimensional applications of the dense national active GNSS networks.

Araszkiewicz, Andrzej; Bogusz, Janusz; Figurski, Mariusz

2010-05-01

7

Fall Semester: A Time for Parents to Revisit Discussions about College Drinking  

MedlinePLUS

... A Time for Parents to Revisit Discussions about College Drinking As college students arrive on campus this fall, it is ... even death. According to research summarized in a College Task Force report to the National Institute on ...

8

Extending creep measurements to short times  

NASA Astrophysics Data System (ADS)

A standard lever arm creep machine (Satec model M-3) is modified to directly measure creep at relatively short times. The modified version of the Satec dead-weight frame can be used to determine momentary creep master curves and to measure short-time creep behavior.

Sullivan, J. L.; Blais, E. J.

1992-12-01

9

Short-term retention of relational memory in amnesia revisited: accurate performance depends on hippocampal integrity  

PubMed Central

Traditionally, it has been proposed that the hippocampus and adjacent medial temporal lobe cortical structures are selectively critical for long-term declarative memory, which entails memory for inter-item and item-context relationships. Whether the hippocampus might also contribute to short-term retention of relational memory representations has remained controversial. In two experiments, we revisit this question by testing memory for relationships among items embedded in scenes using a standard working memory trial structure in which a sample stimulus is followed by a brief delay and the corresponding test stimulus. In each experimental block, eight trials using different exemplars of the same scene were presented. The exemplars contained the same items but with different spatial relationships among them. By repeating the pictures across trials, any potential contributions of item or scene memory to performance were minimized, and relational memory could be assessed more directly than has been done previously. When test displays were presented, participants indicated whether any of the item-location relationships had changed. Then, regardless of their responses (and whether any item did change its location), participants indicated on a forced-choice test, which item might have moved, guessing if necessary. Amnesic patients were impaired on the change detection test, and were frequently unable to specify the change after having reported correctly that a change had taken place. Comparison participants, by contrast, frequently identified the change even when they failed to report the mismatch, an outcome that speaks to the sensitivity of the change specification measure. These results confirm past reports of hippocampal contributions to short-term retention of relational memory representations, and suggest that the role of the hippocampus in memory has more to do with relational memory requirements than the length of a retention interval. PMID:24478681

Yee, Lydia T. S.; Hannula, Deborah E.; Tranel, Daniel; Cohen, Neal J.

2014-01-01

10

DIVERGENCE TIMES AND THE EVOLUTION OF EPIPHYTISM IN FILMY FERNS (HYMENOPHYLLACEAE) REVISITED  

E-print Network

DIVERGENCE TIMES AND THE EVOLUTION OF EPIPHYTISM IN FILMY FERNS (HYMENOPHYLLACEAE) REVISITED Sabine and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan Although the phylogeny of the filmy fern family to examine the diversification of filmy ferns and the evolution of their ecology within a temporal context

Schuettpelz, Eric

11

Fall Semester: A Time for Parents to Revisit Discussions About College Drinking  

E-print Network

Fall Semester: A Time for Parents to Revisit Discussions About College Drinking As college students), the consequences of excessive drinking by college students are more significant, more destructive, and more costly from this report, which were updated recently, indicate that drinking by college students aged 18 to 24

Bezrukov, Sergey M.

12

Cumulant methods and short time propagators  

SciTech Connect

The present paper clarifies a number of issues concerning the general problem of constructing improved short time quantum mechanical propagators. Cumulant methods are shown to be a particularly convenient tool for this task. Numerical results comparing methods based on partial averaging and on gradient approaches are presented for simple model problems and for many particle quantum fluids.

Coalson, R.D. (Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (US)); Freeman, D.L. (Department of Chemistry, University of Rhode Island, Kingston, Rhode Island 02881); Doll, J.D. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545)

1989-10-01

13

Particle creation in a time-dependent electric field revisited  

SciTech Connect

We adopt the general formalism for analyzing evolution of gaussian states of quantized fields in time-dependent backgrounds in the Schrodinger picture (presented in detail in Mahajan and Padmanabhan [G. Mahajan, T. Padmanabhan, Gen. Rel. Grav. 40 (2008) 661]) to study the example of a spatially uniform electric field background (in a time-dependent gauge) which is kept turned on for a finite duration of time. In particular, we study the time-dependent particle content, defined in terms of the concept of instantaneous eigenstates, and describe how it captures the time evolution of the quantized field modes. The actual particle creation process occurs over a relatively short interval in time, and the particle content saturates rather quickly. We also compare the power spectrum of the field modes, computed in the asymptotic limit, with the corresponding situation in a cosmological de Sitter background. Particle creation under the influence of a spiked electric field localized in time, as a particular limiting case of the above general model, is also considered.

Mahajan, Gaurang [IUCAA, Post Bag 4, Ganeshkhind, Pune 411 007 (India)], E-mail: gaurang@iucaa.ernet.in

2009-02-15

14

Transient nanobubbles in short-time electrolysis.  

PubMed

Water electrolysis in a microsystem is observed and analyzed on a short-time scale of ?10 ?s. The very unusual properties of the process are stressed. An extremely high current density is observed because the process is not limited by the diffusion of electroactive species. The high current is accompanied by a high relative supersaturation, S > 1000, that results in homogeneous nucleation of bubbles. On the short-time scale only nanobubbles can be formed. These nanobubbles densely cover the electrodes and aggregate at a later time to microbubbles. The effect is significantly intensified with a small increase of temperature. Application of alternating polarity voltage pulses produces bubbles containing a mixture of hydrogen and oxygen. Spontaneous reaction between gases is observed for stoichiometric bubbles with sizes smaller than ?150 nm. Such bubbles disintegrate violently affecting the surfaces of the electrodes. PMID:23598648

Svetovoy, Vitaly B; Sanders, Remco G P; Elwenspoek, Miko C

2013-05-01

15

Brownian motion at short time scales  

E-print Network

Brownian motion has played important roles in many different fields of science since its origin was first explained by Albert Einstein in 1905. Einstein's theory of Brownian motion, however, is only applicable at long time scales. At short time scales, Brownian motion of a suspended particle is not completely random, due to the inertia of the particle and the surrounding fluid. Moreover, the thermal force exerted on a particle suspended in a liquid is not a white noise, but is colored. Recent experimental developments in optical trapping and detection have made this new regime of Brownian motion accessible. This review summarizes related theories and recent experiments on Brownian motion at short time scales, with a focus on the measurement of the instantaneous velocity of a Brownian particle in a gas and the observation of the transition from ballistic to diffusive Brownian motion in a liquid.

Tongcang Li; Mark G. Raizen

2012-11-07

16

Short rise time intense electron beam generator  

DOEpatents

A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

Olson, Craig L. (Albuquerque, NM)

1987-01-01

17

Biogas from Macroalgae: is it time to revisit the idea?  

PubMed Central

The economic and environmental viability of dedicated terrestrial energy crops is in doubt. The production of large scale biomass (macroalgae) for biofuels in the marine environment was first tested in the late 1960’s. The culture attempts failed due to the engineering challenges of farming offshore. However the energy conversion via anaerobic digestion was successful as the biochemical composition of macroalgae makes it an ideal feedstock. The technology for the mass production of macroalgae has developed principally in China and Asia over the last 50 years to such a degree that it is now the single largest product of aquaculture. There has also been significant technology transfer and macroalgal cultivation is now well tried and tested in Europe and America. The inherent advantage of production of biofuel feedstock in the marine environment is that it does not compete with food production for land or fresh water. Here we revisit the idea of the large scale cultivation of macroalgae at sea for subsequent anaerobic digestion to produce biogas as a source of renewable energy, using a European case study as an example. PMID:23186536

2012-01-01

18

Failure Prevention by Short Time Corrosion Tests  

SciTech Connect

Short time corrosion testing of perforated sheets and wire meshes fabricated from Type 304L stainless steel, Alloy 600 and C276 showed that 304L stainless steel perforated sheet should perform well as the material of construction for dissolver baskets. The baskets will be exposed to hot nitric acid solutions and are limited life components. The corrosion rates of the other alloys and of wire meshes were too high for useful extended service. Test results also indicated that corrosion of the dissolver should drop quickly during the dissolutions due to the inhibiting effects of the corrosion products produced by the dissolution processes.

MICKALONIS, JOHN

2005-05-01

19

Revisiting coincidence rate between Gravitational Wave detection and short Gamma-Ray Burst for the Advanced and third generation  

E-print Network

We use realistic Monte-Carlo simulations including both gravitational-wave and short gamma-ray burst selection effects to revisit the coincident rate of binary systems composed of two neutron stars or a neutron star and a black hole. We show that the fraction of GW triggers that can be observed in coincidence with sGRBs is proportional to the beaming factor at $z=0$, but increases with the distance, until it reaches 100 \\% at the GW detector horizon distance. When this is taken into account the rate is improved by a factor of $~3$ compared to the simple beaming factor correction. We provide an estimate of the performance future GRB detectors should achieve in order to fully exploit the potentiality of the planned third generation GW antenna Einstein Telescope, and we propose a simple method to constrain the beaming angle of sGRBs.

Regimbau, T; Meacher, D; Gendre, B; er, M Bo\\"

2014-01-01

20

Output Decay in Immediate Serial Recall: Speech Time Revisited  

Microsoft Academic Search

Four experiments reexamined the hypothesis that immediate serial recall is limited by the spoken duration of list items during output. In all the experiments, spoken serial recall was measured for visually presented words of short and long duration. The duration of first- and second-half list items was varied independently. Experiment 1 used the disyllabic words from Lovatt, Avons, and Masterson

Peter Lovatt; S. E Avons; Jackie Masterson

2002-01-01

21

REVISITING THE LONG/SOFT-SHORT/HARD CLASSIFICATION OF GAMMA-RAY BURSTS IN THE FERMI ERA  

SciTech Connect

We perform a statistical analysis of the temporal and spectral properties of the latest Fermi gamma-ray bursts (GRBs) to revisit the classification of GRBs. We find that the bimodalities of duration and the energy ratio (E{sub peak}/Fluence) and the anti-correlation between spectral hardness (hardness ratio (HR), peak energy, and spectral index) and duration (T{sub 90}) support the long/soft-short/hard classification scheme for Fermi GRBs. The HR-T{sub 90} anti-correlation strongly depends on the spectral shape of GRBs and energy bands, and the bursts with the curved spectra in the typical BATSE energy bands show a tighter anti-correlation than those with the power-law spectra in the typical BAT energy bands. This might explain why the HR-T{sub 90} correlation is not evident for those GRB samples detected by instruments like Swift with a narrower/softer energy bandpass. We also analyze the intrinsic energy correlation for the GRBs with measured redshifts and well-defined peak energies. The current sample suggests E{sub p,rest} = 2455 Multiplication-Sign (E{sub iso}/10{sup 52}){sup 0.59} for short GRBs, significantly different from that for long GRBs. However, both the long and short GRBs comply with the same E{sub p,rest}-L{sub iso} correlation.

Zhang Fuwen; Yan Jingzhi; Wei Daming [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Shao Lang, E-mail: fwzhang@pmo.ac.cn [Department of Physics, Hebei Normal University, Shijiazhuang 050016 (China)

2012-05-10

22

``Sometimes'' and ``Not Never'' Revisited: On Branching Versus Linear Time  

Microsoft Academic Search

Temporal logic ([PR57], [PR67]) provides a formalism fordescribing the occurrence of events in time which is suitable forreasoning about concurrent programs (cf. [PN77]). In definingtemporal logic, there are two possible views regarding theunderlying nature of time. One is that time is linear: at eachmoment there is only one possible future. The other is that timehas a branching, tree-like nature: at

E. Allen Emerson; Joseph Y. Halpern

1983-01-01

23

Freely floating structures trapping time-harmonic water waves (revisited)  

E-print Network

We study the coupled small-amplitude motion of the mechanical system consisting of infinitely deep water and a structure immersed in it. The former is bounded above by a free surface, whereas the latter is formed by an arbitrary finite number of surface-piercing bodies floating freely. The mathematical model of time-harmonic motion is a spectral problem in which the frequency of oscillations serves as the spectral parameter. It is proved that there exist axisymmetric structures consisting of $N \\geq 2$ bodies; every structure has the following properties: (i) a time-harmonic wave mode is trapped by it; (ii) some of its bodies (may be none) are motionless, whereas the rest of the bodies (may be none) are heaving at the same frequency as water. The construction of these structures is based on a generalization of the semi-inverse procedure applied earlier for obtaining trapping bodies that are motionless although float freely.

Nikolay Kuznetsov; Oleg Motygin

2014-10-22

24

Through the mists of time: Sushrutha, an enigma revisited  

PubMed Central

Sushrutha had been viewed in textbooks of plastic surgery as belonging to the caste of potters who performed surgery in India. We have examined the available source documents and other references to the technology of the period to examine this assertion and are convinced that there is no evidence to support this. The period, technology and geographic references in Sushrutha Samhitha are correlated with settled positions on these to arrive at an understanding of the time and knowledge which is described. Source of erroneous interpretation of Sushrutha as a potter is also examined and clarified. PMID:20368861

Puthumana, Philip Philip

2009-01-01

25

Nuclear Winter Revisited: can it Make a Difference This Time?  

NASA Astrophysics Data System (ADS)

Some 23 years ago, in the middle of a Cold War and the threat of a strategic nuclear weapons exchange between NATO and the Warsaw Pact nations, atmospheric scientists pointed out that the well-anticipated side effects of a large-scale nuclear war ozone depletion, radioactive contamination and some climatic effects had massively underestimated the more likely implications: massive fires, severe dimming and cooling beneath circulating smoke clouds, disruption to agriculture in non-combatant nations, severe loss of imports of food to already-food-deficient regions and major alterations to atmospheric circulation. While the specific consequences were dependent on both scenarios of weapons use and injections and removals of smoke and dust and other chemicals into the atmosphere, it was clear that this would be despite passionately argued uncertainties a large major additional effect. As further investigations of smoke removal, patchy transport, etc., were pursued, the basic concerns remained, but the magnitude calculated with one-dimensional models diminished creating an unfortunate media debate over nuclear winter vs. nuclear autumn. Of course, one can't grow summer crops in any autumn natural or nuclear but that concern often got lost in the contentious political debate. Of course, it was pointed out that anyone who required knowing the additional environmental consequences of a major nuclear exchange to be finally deterred was already so far from the reality of the direct effects of the blasts that they might never see the concerns. But for non-combatants, it was a major awakening of their inability to escape severe consequences of the troubles of others, even if they were bystanders in the east-west conflicts. Two decades later, things have radically changed: the prospect of a massive strategic nuclear exchange is greatly diminished good news but the possibility of limited regional exchanges or terrorist incidents is widely believed to have greatly increased bad news. Therefore, the re- examination in this AGU session of the entire subject of environmental and social after-effects of any nuclear weapons use is, unfortunately, once again timely. Hopefully it will convince anyone not already convinced based on conventional damages from nuclear weapons use of the urgent need to abate proliferation and monitor and control access to and potential capabilities of those who might contemplate using such weapons for some Strangelove-like strategic or ideological objective. The extent to which a scientific re-examination of the broader horrendous implications of any scale of use of nuclear weapons will deter those contemplating their use is questionable. However, it seems likely such research would increase the resolve of the large number of countries and institutions already pressing to prevent nuclear weapons use.

Schneider, S.

2006-12-01

26

The Demise of Short-Term Memory Revisited: Empirical and Computational Investigations of Recency Effects  

Microsoft Academic Search

In the single-store model of memory, the enhanced recall for the last items in a free-recall task (i.e., the recency effect) is understood to reflect a general property of memory rather than a separate short-term store. This interpretation is supported by the finding of a long-term recency effect under conditions that eliminate the contribution from the short-term store. In this

Eddy J. Davelaar; Yonatan Goshen-Gottstein; Amir Ashkenazi; Henk J. Haarmann; Marius Usher

2005-01-01

27

Real-time NURBS interpolator: application to short linear segments  

Microsoft Academic Search

This study proposes the use of a real-time non-uniform rational B-spline (NURBS) interpolator with a look-ahead function to\\u000a handle numerous short linear segments. The short linear segments conforming to the continuous short block (CSB) criterion\\u000a can be fitted into NURBS curves in real time. A modified maximum feedrate equation based on the geometric characteristics\\u000a of the fitting curves and the

Jun-Bin Wang; Hong-Tzong Yau

2009-01-01

28

Short time aging in binary glasses Giorgio Parisi  

E-print Network

Short time aging in binary glasses Giorgio Parisi Dipartimento di Fisica, Universit`a La Sapienza computer simulations that indicate that at short time aging is realized in a simple model of binary glasses done. Aging has being studied analytically in generalized spin glasses: in the simplest form

Roma "La Sapienza", Università di

29

The Short-Time Multifractal Formalism: Definition and Implement  

NASA Astrophysics Data System (ADS)

Although multifractal descirbles the singularity distribution of SE, there is no time information in the multifractal formalism, and the time-varying singularity distribution indicates the spatial dynamics character of system. Therefore, the definition and implement of the short-time multifractal formalism is proposed, which is the prelude of time time-singularity spectra distribution. In this paper, the singularity analysis of windowed signal was given, further the short-time hausdorff spectum was deduced. The Partition Function and Short-time Legendre Spectrum was fractal statistical distribution of SE. WTMM method is popular in implement of MFA, and in section IV,Short-time multifractal spectra based on WTMM is brough forward.

Gang, Xiong; Xiaoniu, Yang; Huichang, Zhao

30

Improving music genre classification by short time feature integration  

Microsoft Academic Search

Many different short-time features, using time windows of 10-30 ms, have been proposed for music segmentation, retrieval and genre classification. However, often the available time frame of the music to make the actual decision or comparison (the decision time horizon) is in the range of seconds instead of milliseconds. The problem of making new features on the larger time scale

Anders Meng; Peter Ahrendt; Jan Larsen

2005-01-01

31

Market volatility modeling for short time window  

NASA Astrophysics Data System (ADS)

The gain or loss of an investment can be defined by the movement of the market. This movement can be estimated by the difference between the magnitudes of two stock prices in distinct periods and this difference can be used to calculate the volatility of the markets. The volatility characterizes the sensitivity of a market change in the world economy. Traditionally, the probability density function (pdf) of the movement of the markets is analyzed by using power laws. The contributions of this work is two-fold: (i) an analysis of the volatility dynamic of the world market indexes is performed by using a two-year window time data. In this case, the experiments show that the pdf of the volatility is better fitted by exponential function than power laws, in all range of pdf; (ii) after that, we investigate a relationship between the volatility of the markets and the coefficient of the exponential function based on the Maxwell-Boltzmann ideal gas theory. The results show an inverse relationship between the volatility and the coefficient of the exponential function. This information can be used, for example, to predict the future behavior of the markets or to cluster the markets in order to analyze economic patterns.

de Mattos Neto, Paulo S. G.; Silva, David A.; Ferreira, Tiago A. E.; Cavalcanti, George D. C.

2011-10-01

32

The Short-Time Multifractal Formalism: Definition and Implement  

Microsoft Academic Search

Although multifractal descirbles the singularity distribution of SE, there is no time information in the multifractal formalism, and the time-varying singularity distribution indicates the spatial dynamics character of system. Therefore, the definition and implement of the short-time multifractal formalism is proposed, which is the prelude of time time-singularity spectra distribution. In this paper, the singularity analysis of windowed signal was

Xiong Gang; Yang Xiaoniu; Zhao Huichang

2008-01-01

33

IMPROVING MUSIC GENRE CLASSIFICATION BY SHORT-TIME FEATURE INTEGRATION  

E-print Network

IMPROVING MUSIC GENRE CLASSIFICATION BY SHORT-TIME FEATURE INTEGRATION Anders Meng, Peter Ahrendt- trieval and genre classification. However, often the available time frame of the music to make the actual and late information fusion1 for music genre classification. A new feature integration technique, the AR

34

On the short-time behavior of porous intercalation electrodes  

SciTech Connect

The reaction-rate distribution in a porous electrode containing an intercalation compound is examined theoretically. Particular attention is paid to the influence of the exchange current density on the propagation of the reaction through the depth of the electrode at short times. The governing differential equations are nondimensionalized, linearized, and applied to semi-infinite electrode and separator regions. A LaPlace transform of the solution to this problem is presented, and asymptotes are developed for short and moderate times. These limiting forms are compared to the results of numerical simulations. The short-time reaction-rate distribution consistent with the assumption of an arbitrarily large exchange current density is presented and analyzed.

Darling, R.; Newman, J. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.]|[Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

1997-09-01

35

Design of self-refocused pulses under short relaxation times.  

PubMed

The effect of using self-refocused RF pulses of comparable duration to relaxation times is studied in detail using numerical simulation. Transverse magnetization decay caused by short T2 and longitudinal component distortion due to short T1 are consistent with other studies. In order to design new pulses to combat short T1 and T2 the relaxation terms are directly inserted into the Bloch equations. These equations are inverted by searching the RF solution space using simulated annealing global optimization technique. A new T2-decay efficient excitation pulse is created (SDETR: single delayed excursion T2 resistive) which is also energy efficient. Inversion pulses which improve the inverted magnetization profile and achieve better suppression of the remaining transverse magnetization are also created even when both T1 and T2 are short. This is achieved, however, on the expense of a more complex B1 shape of larger energy content. PMID:19272823

Issa, Bashar

2009-06-01

36

Improving TWSTFT short-term stability by network time transfer.  

PubMed

Two-way satellite time and frequency transfer (TWSTFT) is one of the major techniques to compare the atomic time scales between timing laboratories. As more and more TWSTFT measurements have been performed, the large number of point-to-point 2-way time transfer links has grown to be a complex network. For future improvement of the TWSTFT performance, it is important to reduce measurement noise of the TWSTFT results. One method is using TWSTFT network time transfer. The Asia-Pacific network is an exceptional case of simultaneous TWSTFT measurements. Some indirect links through relay stations show better shortterm stabilities than the direct link because the measurement noise may be neutralized in a simultaneous measurement network. In this paper, the authors propose a feasible method to improve the short-term stability by combining the direct and indirect links in the network. Through the comparisons of time deviation (TDEV), the results of network time transfer exhibit clear improved short-term stabilities. For the links used to compare 2 hydrogen masers, the average gain of TDEV at averaging times of 1 h is 22%. As TWSTFT short-term stability can be improved by network time transfer, the network may allow a larger number of simultaneously transmitting stations. PMID:20040441

Tseng, Wen-Hung; Lin, Shinn-Yan; Feng, Kai-Ming; Fujieda, M; Maeno, H

2010-01-01

37

Speech processing based on short-time Fourier analysis  

SciTech Connect

Short-time Fourier analysis (STFA) is a mathematical technique that represents nonstationary signals, such as speech, music, and seismic signals in terms of time-varying spectra. This representation provides a formalism for such intuitive notions as time-varying frequency components and pitch contours. Consequently, STFA is useful for speech analysis and speech processing. This paper shows that STFA provides a convenient technique for estimating and modifying certain perceptual parameters of speech. As an example of an application of STFA of speech, the problem of time-compression or expansion of speech, while preserving pitch and time-varying frequency content is presented.

Portnoff, M.R.

1981-06-02

38

Signal estimation from modified short-time Fourier transform  

Microsoft Academic Search

In this paper, we present an algorithm to estimate a signal from its modified short-time Fourier transform (STFT). This algorithm is computationally simple and is obtained by minimizing the mean squared error between the STFT of the estimated signal and the modified STFT. Using this algorithm, we also develop an iterative algorithm to estimate a signal from its modified STFT

DANIEL W. GRIFFIN; JAE S. LIM

1984-01-01

39

Short Time Series Analysis: C Statistic vs Edgington Model  

Microsoft Academic Search

Young's C statistic (1941) makes it possible to compare the randomization of a set of sequentially organized data and constitutes an alternative of appropriate analysis in short time series designs. On the other hand, models based on the randomization of stimuli are also very important within the behavioral content applied. For this reason, a comparison is established between the C

Jaume Arnau; Roser Bono

1998-01-01

40

(abstract) Short Time Period Variations in Jupiter's Synchrotron Radiation  

NASA Technical Reports Server (NTRS)

The long term time variability of Jupiter's synchrotron radiation on yearly time scales has been established for some time. For many years, theorists have speculated about the effects variations in the solar wind, solar flux, Io, the Io torus, and Jupiter's magnetic field have on the ultra-relativistic electron population responsible for the emission. Early observational results suggested the additional possibility of a short term time variability, on timescales of days to weeks. In 1989 a program designed to investigate the existence of short term time variability using the 85 foot Hat Creek radio telescope operating at 1400 MHz was initiated. The availability of a dedicated telescope provided the opportunity, for the first time, to obtain numerous observations over the full Jupiter rotation period. These and future observations will enable two important studies, characterization and confirmation of possible short term variations, and the investigation of the stability of Jupiter's synchrotron emission beaming curve. Analysis of Hat Creek observations and early results from the Maryland Point Naval research Laboratory will be presented.

Bolton, S. J.; Klein, M. J.; Gulkis, S.; Foster, R.; Heiles, C.; Pater, I. de

1994-01-01

41

Minimal model for short-time diffusion in periodic potentials.  

PubMed

We investigate the dynamics of a single, overdamped colloidal particle, which is driven by a constant force through a one-dimensional periodic potential. We focus on systems with large barrier heights where the lowest-order cumulants of the density field, that is, average position and the mean-squared displacement, show nontrivial (nondiffusive) short-time behavior characterized by the appearance of plateaus. We demonstrate that this "cage-like" dynamics can be well described by a discretized master equation model involving two states (related to two positions) within each potential valley. Nontrivial predictions of our approach include analytic expressions for the plateau heights and an estimate of the "de-caging time" obtained from the study of deviations from Gaussian behavior. The simplicity of our approach means that it offers a minimal model to describe the short-time behavior of systems with hindered dynamics. PMID:23367921

Emary, Clive; Gernert, Robert; Klapp, Sabine H L

2012-12-01

42

The Duration of Trade Revisited. Continuous-Time vs. Discrete-Time Hazards  

Microsoft Academic Search

The recent literature on the duration of trade has predominantly analyzed the determinants of trade flow durations using Cox proportional hazards models. The purpose of this paper is to show why it is inappropriate to analyze the duration of trade with continuous-time models such as the Cox model, and to propose alternative discrete-time models which are more suitable for estimation.

Wolfgang Hess; Maria Persson

2010-01-01

43

The Duration of Trade Revisited: Continuous-Time vs. Discrete-Time Hazards  

Microsoft Academic Search

The recent literature on the duration of trade has predominantly analyzed the determinants of trade flow durations using Cox proportional hazards models. The purpose of this paper is to show why it is inappropriate to analyze the duration of trade with continuous-time models such as the Cox model, and to propose alternative discrete-time models which are more suitable for estimation.

Wolfgang Hess; Maria Persson

2010-01-01

44

Non-24-Hour Disorder in Blind Individuals Revisited: Variability and the Influence of Environmental Time Cues  

PubMed Central

Study Objectives: To assess the interindividual and intraindividual variability in the circadian rhythms of blind individuals with non-24-h disorder and to quantify the influence of environmental time cues in blind subjects lacking entrainment (non-24-h individuals or N-24s). Design: An observational study of 21 N-24s (11 females and 10 males, age 9-78 years) who kept a sleep/wake schedule of their choosing. Circadian phase was determined using the melatonin onset (MO) from plasma or saliva samples that were collected every 2 weeks. Melatonin concentrations were measured by radioimmunoassay. A total of 469 MO assessments were conducted over 5,536 days of study. The rate of drift of circadian phase was calculated using a series of MOs (total number of hours the MO drifted divided by the total number of days studied). Stability of the rest/activity rhythm was calculated using chi-squared periodogram analysis of wrist actigraphy data in 19 subjects. Setting: Academic medical center. Participants: Paid volunteers. Interventions: N/A. Measurements and Results: Subjects lacked entrainment such that circadian phase drifted an average (± standard deviation) of 0.39 ± 0.29 h later per day; however, there was notable intersubject and intrasubject variability in the rate of drift including relative coordination and periods of transient entrainment during which there was little to no drift in the circadian phase. A regular, reproducible, and significant oscillation in the rate of drift was detected in 14 of the 21 subjects. A significant non-24-h rest/activity rhythm was detected in 18 of 19 subjects. There was a strong correlation (r = 0.793, P = 0.0001) between the non-24-h rest/activity rhythm and the rate of drift of the circadian phase. Conclusions: Most N-24s are influenced by unidentified environmental time cues and the non-entrained biological clock in such N-24s is reflected in their rest/activity rhythms. These findings may have diagnostic and treatment implications: this disorder might be diagnosed with actigraphy alone, relative coordination and transient entrainment may result in misdiagnosis and responsiveness to environmental time cues may influence treatment success with oral melatonin. Citation: Emens JS; Laurie AL; Songer JB; Lewy AJ. Non-24-hour disorder in blind individuals revisited: variability and the influence of environmental time cues. SLEEP 2013;36(7):1091-1100. PMID:23814347

Emens, Jonathan S.; Laurie, Amber L.; Songer, Jeannie B.; Lewy, Alfred J.

2013-01-01

45

Performance of multifractal detrended fluctuation analysis on short time series  

NASA Astrophysics Data System (ADS)

The performance of the multifractal detrended analysis on short time series is evaluated for synthetic samples of several mono- and multifractal models. The reconstruction of the generalized Hurst exponents is used to determine the range of applicability of the method and the precision of its results as a function of the decreasing length of the series. As an application the series of the daily exchange rate between the U.S. dollar and the euro is studied.

López, Juan Luis; Contreras, Jesús Guillermo

2013-02-01

46

Performance of multifractal detrended fluctuation analysis on short time series  

E-print Network

The performance of the multifractal detrended analysis on short time series is evaluated for synthetic samples of several mono- and multifractal models. The reconstruction of the generalized Hurst exponents is used to determine the range of applicability of the method and the precision of its results as a function of the decreasing length of the series. As an application the series of the daily exchange rate between the U.S. dollar and the euro is studied.

Lopez, Juan Luis

2013-01-01

47

Short-time scale behavior modeling within long-time scale fuel cycle evaluations  

SciTech Connect

Typically, short-time and long-time scales in nuclear energy system behavior are accounted for with entirely separate models. However, long-term changes in system characteristics do affect short-term transients through material variations. This paper presents an approach to consistently account for short-time scales within a nuclear system lifespan. The reported findings and developments are of significant importance for small modular reactors and other nuclear energy systems operating in autonomous modes. It is necessary to simulate the short time-scale kinetic behavior of the reactor as well as the long time-scale dynamics that occur with fuel burnup. The former is modeled using the point kinetics equations, while the latter is modeled by the Bateman equations. (authors)

Johnson, M.; Tsvetkov, P. [Dept. of Nuclear Engineering, Texas A and M Univ., 3133 TAMU, College Station, TX 77843 (United States); Lucas, S. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 (United States)

2012-07-01

48

The late--time tails in the Reissner--Nordström space-time revisited  

NASA Astrophysics Data System (ADS)

We propose that the late-time tail problem in the Reissner-Nordström (RN) spacetime is dual to a tail problem in the Schwarzschild spacetime with a different initial data set: at a fixed observation point the asymptotic decay rate of the fields are equal. This duality is used to find the decay rate for tails in RN. This decay rate is exactly as in Schwarzschild, including the case of the extremely-charged RN spacetime (ERN). The only case where any deviation from the Schwarzschild decay rate is found is the case of the tails along the event horizon of an ERN spacetime, where the decay rate is the same as at future null infinity. As observed at a fixed location, the decay rate in ERN is the same as in Schwarzschild. We verify these expectations with numerical simulations.

Blaksley, Carl J.; Burko, Lior M.

2008-04-01

49

Predator-prey interactions, resource depression and patch revisitation  

USGS Publications Warehouse

Generalist predators may be confronted by different types of prey in different patches: sedentary and conspicuous, cryptic (with or without refugia), conspicuous and nonsocial, or conspicuous and social. I argue that, where encounter rates with prey are of most importance, patch revisitation should be a profitable tactic where prey have short 'recovery' times (conspicuous, nonsocial prey), or where anti-predator response (e.g. shoaling) may increase conspicuousness. Predictions are made for how temporal changes in prey encounter rates should affect revisit schedules and feeding rates for the 4 different prey types.

Erwin, R.M.

1989-01-01

50

Short- and Long- Time Transport Structures in a Three Dimensional Time Dependent Flow  

E-print Network

Lagrangian transport structures for three-dimensional and time-dependent fluid flows are of great interest in numerous applications, particularly for geophysical or oceanic flows. In such flows, chaotic transport and mixing can play important environmental and ecological roles, for examples in pollution spills or plankton migration. In such flows, where simulations or observations are typically available only over a short time, understanding the difference between short-time and long-time transport structures is critical. In this paper, we use a set of classical (i.e. Poincar\\'e section, Lyapunov exponent) and alternative (i.e. finite time Lyapunov exponent, Lagrangian coherent structures) tools from dynamical systems theory that analyze chaotic transport both qualitatively and quantitatively. With this set of tools we are able to reveal, identify and highlight differences between short- and long-time transport structures inside a flow composed of a primary horizontal contra-rotating vortex chain, small later...

Chabreyrie, Rodolphe

2014-01-01

51

DECISION TIME HORIZON FOR MUSIC GENRE CLASSIFICATION USING SHORT TIME FEATURES  

E-print Network

DECISION TIME HORIZON FOR MUSIC GENRE CLASSIFICATION USING SHORT TIME FEATURES Peter Ahrendt music genre classification has been explored with spe- cial emphasis on the decision time horizon with a portable or stationary computer. A few researchers have attended the specific problem of music genre

52

Target time smearing with short transmissions and multipath propagation.  

PubMed

In active sonar the target echo level is often estimated with a propagation model that adds all multipath arrivals. If the (post-correlator) transmitted pulse is short compared to the multipath time spread then there is effectively an extra loss (which may be substantial) since only a few of the paths contribute to the target echo at any one instant. This well known "time-smearing" loss is treated in a self-consistent manner with previous calculations of reverberation [Harrison, J. Acoust. Soc. Am. 114, 2744-2756 (2003)] to estimate the target response and the signal-to-reverberation-ratio. Again isovelocity water, Lambert's law, and reflection loss proportional to angle are assumed. In this important short pulse regime the target response becomes independent of boundary reflection properties but proportional to transmitted pulse length. Thus the signal-to-reverberation-ratio becomes independent of pulse length. The effect on signal-to-ambient-noise is also investigated and the resulting formulas presented in a table. PMID:21895070

Harrison, Chris H

2011-09-01

53

Short time die attach characterisation of semiconductor devices  

E-print Network

Thermal qualification of the die attach of semiconductor devices is a very important element in the device characterization as the temperature of the chip is strongly affected by the quality of the die attach. Voids or delaminations in this layer may cause higher temperature elevation and thus damage or shorter lifetime. Thermal test of each device in the manufacturing process would be the best solution for eliminating the devices with wrong die attach layer. In this paper we will present the short time thermal transient measurement method and the structure function evaluation through simulations and measurements for die attach characterization. We will also present a method for eliminating the very time consuming calibration process. Using the proposed methods even the in-line testing of LEDs can be accomplished.

P. Szabo; M. Rencz

2008-01-07

54

Short-time multifractal analysis: application to biological signals  

NASA Astrophysics Data System (ADS)

Some signals obtained from biological systems evince a great complexity. Recently, new tools which allow the extraction of information from them have been proposed. In particular, multifractal analysis gives a quantification of the degree and distribution of irregularities in a signal. A possible approach for this analysis is the one based on wavelet leaders. In this work, the use of wavelet leader based multifractal analysis in short-time windows is proposed in order to analyze the evolution of the multifractal behavior of biological signals. In particular, applications of this technique to the detection of ischemic episodes in heart rate variability signals and to voice activity detection are examined. It is shown that the study of the time evolution of indexes obtained with the proposed new method gives useful information hidden in the signals.

Leonarduzzi, Roberto F.; Schlotthauer, Gastón; Torres, María E.

2011-09-01

55

Coupling among Electroencephalogram Gamma Signals on a Short Time Scale  

PubMed Central

An important goal in neuroscience is to identify instances when EEG signals are coupled. We employ a method to measure the coupling strength between gamma signals (40–100?Hz) on a short time scale as the maximum cross-correlation over a range of time lags within a sliding variable-width window. Instances of coupling states among several signals are also identified, using a mixed multivariate beta distribution to model coupling strength across multiple gamma signals with reference to a common base signal. We first apply our variable-window method to simulated signals and compare its performance to a fixed-window approach. We then focus on gamma signals recorded in two regions of the rat hippocampus. Our results indicate that this may be a useful method for mapping coupling patterns among signals in EEG datasets. PMID:20811477

McAssey, Michael P.; Hsieh, Fushing; Smith, Anne C.

2010-01-01

56

Common structure in panels of short ecological time-series.  

PubMed Central

Typically, in many studies in ecology, epidemiology, biomedicine and others, we are confronted with panels of short time-series of which we are interested in obtaining a biologically meaningful grouping. Here, we propose a bootstrap approach to test whether the regression functions or the variances of the error terms in a family of stochastic regression models are the same. Our general setting includes panels of time-series models as a special case. We rigorously justify the use of the test by investigating its asymptotic properties, both theoretically and through simulations. The latter confirm that for finite sample size, bootstrap provides a better approximation than classical asymptotic theory. We then apply the proposed tests to the mink-muskrat data across 81 trapping regions in Canada. Ecologically interpretable groupings are obtained, which serve as a necessary first step before a fuller biological and statistical analysis of the food chain interaction. PMID:11133038

Yao, Q; Tong, H; Finkenstadt, B; Stenseth, N C

2000-01-01

57

A study of Venus rotation at short time scale  

NASA Astrophysics Data System (ADS)

Venus which can be considered as the twin sister of the Earth in view of its global characteristics (size, density) has been the subject of many investigations to understand its slow retrograde rotation (243d) and its rather small obliquity (2°.63). Many of these studies concern the evolution of Venus rotation at very long time scales. Here we present a complete model of Venus precession and nutation based on Hamiltonian formalism for short times scales. We apply a theoretical framework already used by Kinoshita (1977) for the rigid Earth. After calculating the effects due to the gravitational tide exerted by the Sun, we also evaluate the indirect planetary effects due to the perturbation of the planets. We compare our results with those obtained by Souchay et al. (1999) on the Earth. At last we present the prospect for future studies among which are the polhody, the effects of the atmosphere and of the core-mantle interaction.

Cottereau, L.; Souchay, J.

2009-12-01

58

Short Lyapunov time: a method for identifying confined chaos  

NASA Astrophysics Data System (ADS)

Context. The orbital instability of minor solar system bodies (asteroids, small satellites, moonlets, and particles) is frequently studied in terms of the Lyapunov characteristic exponent (LCE). Asteroids interior to Jupiter often exihibit very short Lyapunov times, TL, and very large radial variations, becoming Jupiter's crossers and escapers. However, a few cases of asteroids with very short TL and no significant radial variation have been found. These orbits were called “confined chaos” or even “stable chaos”. This feature also appeared in the case of moonlets embedded in Saturn's F ring and disturbed by the nearby satellites Prometheus and Pandora. Aims: We present a simple approach to estimating the contribution of the radial component of the LCE to identify trajectories in the “confined chaos” regime. Methods: To estimate the radial contribution to the maximum LCE, we considered a rotating reference system in which one of the axis was aligned with the radial direction of the reference trajectory. Measuring the distance in the phase space between the two nearby orbits then allowed us to separate the contribution of the radial component from the others. We applied the method to two different dynamical systems: (a) an asteroid around the Sun disturbed by Jupiter; (b) a moonlet of Saturn's F-ring disturbed by the satellites Prometheus and Pandora. Results: In all cases, we found that the method of comparing the radial contribution of the LCE to the entire contribution allows us to correctly distinguish between confined chaos and escapers.

Winter, O. C.; Mourão, D. C.; Giuliatti Winter, S. M.

2010-11-01

59

Short and long time drop dynamics on lubricated substrates  

NASA Astrophysics Data System (ADS)

Liquid infiltrated solids have been proposed as functional solvent-phobic surfaces for handling single and multiphase flows. Implementation of such surfaces alters the interfacial transport phenomenon as compared to a dry substrate. To better understand the interface characteristics in such systems we study experimentally the dynamics of a pendant water drop in air that contacts a substrate coated by thin oil films. At short times the water drop is deformed by the oil that spreads onto the water-air interface, and the dynamics are characterized by inertial and viscous regimes. At late times, the the oil film under the drop relaxes either to a stable thin film or ruptures. In the thin film rupture regime, we measure the waiting time for the rupture as a function of the drop equilibrium contact angle on a dry substrate and the initial film height. The waiting time is rationalized by lubrication theory, which indicates that long-range intermolecular forces destabilize the oil-water interface and is the primary mechanism for the film drainage.

Carlson, A.; Kim, P.; Amberg, G.; Stone, H. A.

2013-11-01

60

Short- and Long- Time Transport Structures in a Three Dimensional Time Dependent Flow  

E-print Network

Lagrangian transport structures for three-dimensional and time-dependent fluid flows are of great interest in numerous applications, particularly for geophysical or oceanic flows. In such flows, chaotic transport and mixing can play important environmental and ecological roles, for examples in pollution spills or plankton migration. In such flows, where simulations or observations are typically available only over a short time, understanding the difference between short-time and long-time transport structures is critical. In this paper, we use a set of classical (i.e. Poincar\\'e section, Lyapunov exponent) and alternative (i.e. finite time Lyapunov exponent, Lagrangian coherent structures) tools from dynamical systems theory that analyze chaotic transport both qualitatively and quantitatively. With this set of tools we are able to reveal, identify and highlight differences between short- and long-time transport structures inside a flow composed of a primary horizontal contra-rotating vortex chain, small lateral oscillations and a weak Ekman pumping. The difference is mainly the existence of regular or extremely slowly developing chaotic regions that are only present at short time.

Rodolphe Chabreyrie; Stefan G. Llewellyn Smith

2014-05-08

61

Short-time vibrational dynamics of metaphosphate glasses  

NASA Astrophysics Data System (ADS)

In this paper we present the picosecond vibrational dynamics of a series of binary metaphosphate glasses, namely Na2O-P2O5, MO-P2O5 (M=Ba, Sr, Ca, Mg) and Al2O3-3P2O5 by means of Raman spectroscopy. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The fitting method used enables one to model the real line profiles intermediate between Lorentzian and Gaussian by an analytical function, which has an analytical counterpart in the time domain. The symmetric stretching modes ?s(PO2-) and ?s(P-O-P) of the PO2- entity of PØ2O2- units and of P-O-P bridges in metaphosphate arrangements have been investigated by Raman spectroscopy and we used them as probes of the dynamics of these glasses. The vibrational time correlation functions of both modes studied are rather adequately interpreted within the assumption of exponential modulation function in the context of Kubo-Rothschield theory and indicate that the system experiences an intermediate dynamical regime that gets only slower with an increase in the ionic radius of the cation-modifier. We found that the vibrational correlation functions of all glasses studied comply with the Rothschild approach assuming that the environmental modulation is described by a stretched exponential decay. The evolution of the dispersion parameter ? with increasing ionic radius of the cation indicates the deviation from the model simple liquid indicating the reduction of the coherence decay in the perturbation potential as a result of local short lived aggregates. The results are discussed in the framework of the current phenomenological status of the field.

Kalampounias, Angelos G.

2012-02-01

62

DECISION TIME HORIZON FOR MUSIC GENRE CLASSIFICATION USING SHORT TIME FEATURES  

Microsoft Academic Search

In this paper music genre classification has been explored with spe- cial emphasis on the decision time horizon and ranking of tapped- delay-line short-time features. Late information fusion as e.g. ma- jority voting is compared with techniques of early information fu- sion1 such as dynamic PCA (DPCA). The most frequently sug- gested features in the literature were employed including mel-

Peter Ahrendt; Anders Meng; Jan Larsen

2004-01-01

63

Short-time-evolved wave functions for solving quantum many-body problems  

E-print Network

converges essentially to the exact ground state in a relatively short time. Thus a short-time evolved wave function can be an excellent approximation to the exact ground state. Such a short-time-evolved wave function can be obtained by factorizing...

Ciftja, O.; Chin, Siu A.

2003-01-01

64

Revisiting the van Trees inequality in the spirit of Hajek and Le Cam Elisabeth Gassiat  

E-print Network

Revisiting the van Trees inequality in the spirit of H´ajek and Le Cam Elisabeth Gassiat form and under minimal assumptions, in the spirit of H´ajek and Le Cam. We prove that the van Trees in the spirit of H´ajek and Le Cam 1. Introduction A long story made short. Once upon a time (in April 2001

Gassiat, Elisabeth

65

SHORT COMMUNICATION: Time measurement device with four femtosecond stability  

NASA Astrophysics Data System (ADS)

We present the experimental results of extremely precise timing in the sense of time-of-arrival measurements in a local time scale. The timing device designed and constructed in our laboratory is based on a new concept using a surface acoustic wave filter as a time interpolator. Construction of the device is briefly described. The experiments described were focused on evaluating the timing precision and stability. Low-jitter test pulses with a repetition frequency of 763 Hz were generated synchronously to the local time base and their times of arrival were measured. The resulting precision of a single measurement was typically 900 fs RMS, and a timing stability TDEV of 4 fs was achieved for time intervals in the range from 300 s to 2 h. To our knowledge this is the best value reported to date for the stability of a timing device. The experimental results are discussed and possible improvements are proposed.

Panek, Petr; Prochazka, Ivan; Kodet, Jan

2010-10-01

66

Using short time pressure buildup tests to calculate gas reserves  

E-print Network

Short-Term Pressure Buildup Tests for Gas Reserves Estimation in Tight Gas Reservoirs, " paper SPE 17707 presented at the 1988 Gas Technology Symposium, Dallas, Texas, June ' 13-15. Al-Hussainy, R. , Ramey Jr. , H, J. , and Crawford, P. B. : "The... Flow of Real Gases Through Porous Media, " ~r P~T~h(May, 1966) 624-636. AI-Hussainy, R. , Ramey Jr?H. J. , and Crawford, P. B. : "Application of Real Gas Flow Theory to Well Testing and Deliverability Forecasting, " Jour. Pet. Tech. (May, 1966) 637...

Vu, Trang Dinh

2012-06-07

67

Short-term load forecasting using time series analysis: A case study for Singapore  

Microsoft Academic Search

This paper presents time series analysis for short-term Singapore electricity demand forecasting. Two time series models are proposed, namely, the multiplicative decomposition model and the seasonal ARIMA Model. Forecasting errors of both models are computed and compared. Results show that both time series models can accurately predict the short-term Singapore demand and that the Multiplicative decomposition model slightly outperforms the

Jianguang Deng; Panida Jirutitijaroen

2010-01-01

68

An Incremental Algorithm for Signal Reconstruction from Short-Time Fourier Transform Magnitude  

E-print Network

An Incremental Algorithm for Signal Reconstruction from Short-Time Fourier Transform Magnitude Jake-time Fourier transform (STFT). In contrast to existing algorithms based on alternating projections, we offer-domain signal from only the magnitude of the short-time Fourier transform (STFT) is a common prob- lem in speech

Poggio, Tomaso

69

Improving TWSTFT short-term stability by network time transfer  

Microsoft Academic Search

Two-way satellite time and frequency transfer (TWSTFT) is one of the major techniques to compare the atomic time scales between timing laboratories. As more and more TWSTFT measurements have been performed, the large number of point-to-point 2-way time transfer links has grown to be a complex network. For future improvement of the TWSTFT performance, it is important to reduce measurement

Wen-Hung Tseng; Shinn-Yan Lin; Kai-Ming Feng; Miho Fujieda; Hideo Maeno

2010-01-01

70

Improving TWSTFT short-term stability by network time transfer  

Microsoft Academic Search

Two Way Satellite Time and Frequency Transfer (TWSTFT) is one of the major techniques to compare the atomic time scales between timing laboratories. As more and more TWSTFT measurements are performed, large numbers of point-to-point two-way time transfer links have grown to be a complex network. For a future improvement of the TWSTFT performance, it is getting important to reduce

Wen-Hung Tseng; Shinn-Yan Lin; Kai-Ming Feng; Miho Fujieda; Hideo Maeno

2009-01-01

71

It is time to revisit current dietary recommendations for saturated fat.  

PubMed

The extent to which a high intake of saturated fat (SFA) increases the risk of cardiovascular disease (CVD) has become a highly controversial topic. Dietary SFA primarily raises low-density lipoprotein cholesterol, while having a relatively neutral impact on other key CVD risk factors. Recent epidemiological data also challenge the concept that SFA increases the risk of CVD. This short review provides arguments for the urgency to re-assess the association between dietary SFA and CVD risk in light of recent data on the subject. PMID:25293492

Lamarche, Benoît; Couture, Patrick

2014-12-01

72

Healthy Work Revisited: Do Changes in Time Strain Predict Well-Being?  

PubMed Central

Building on Karasek and Theorell (R. Karasek & T. Theorell, 1990, Healthy work: Stress, productivity, and the reconstruction of working life, New York, NY: Basic Books), we theorized and tested the relationship between time strain (work-time demands and control) and seven self-reported health outcomes. We drew on survey data from 550 employees fielded before and 6 months after the implementation of an organizational intervention, the Results Only Work Environment (ROWE) in a white-collar organization. Cross-sectional (Wave 1) models showed psychological time demands and time control measures were related to health outcomes in expected directions. The ROWE intervention did not predict changes in psychological time demands by Wave 2, but did predict increased time control (a sense of time adequacy and schedule control). Statistical models revealed increases in psychological time demands and time adequacy predicted changes in positive (energy, mastery, psychological well-being, self-assessed health) and negative (emotional exhaustion, somatic symptoms, psychological distress) outcomes in expected directions, net of job and home demands and covariates. This study demonstrates the value of including time strain in investigations of the health effects of job conditions. Results encourage longitudinal models of change in psychological time demands as well as time control, along with the development and testing of interventions aimed at reducing time strain in different populations of workers. PMID:23506547

Moen, Phyllis; Kelly, Erin L.; Lam, Jack

2013-01-01

73

Twitch Crowdsourcing: Crowd Contributions in Short Bursts of Time  

E-print Network

often drop out when life becomes busy [21]. Even seemingly small time requirements can dissuade users of crowdsourcing campaigns will struggle to succeed as long as potential contributors are deterred by the time, existing mobile crowdsourcing platforms (e.g., [12,16,22]) tend to assume long, focused runs of work. Our

Pratt, Vaughan

74

Short time dissolved oxygen dynamics in shallow water ecosystems  

Microsoft Academic Search

Dissolved oxygen evolution over time holds information about the recent and past history of the physics, the chemistry and the biology of aquatic systems. On the daily time scale various phenomena seem to repeat with a sort of regularity, leaving a trace in the further trend of oxygen dynamics. These are the wind calm of nocturnal and early morning hours,

Roberto D’Autilia; Margherita Falcucci; Vincent Hull; Luisa Parrella

2004-01-01

75

Revisiting the Development of Time Sharing Using a Dual Motor Task Performance  

ERIC Educational Resources Information Center

In this article, the authors discuss and examine how to develop time sharing using a dual motor task and its effects. They state that when one is required to perform two tasks at the same time (time sharing), an individual may experience difficulty in expressing one or both of the tasks. This phenomenon, known as interference, has been studied…

Getchell, Nancy; Pabreja, Priya

2006-01-01

76

32ND INTERNATIONAL COSMIC RAY CONFERENCE, BEIJING 2011 Heliocentric Distance of CMEs at the Time of Energetic Particle Release: Revisit-  

E-print Network

of Energetic Particle Release: Revisit- ing the Ground Level Enhancement Events of Solar Cycle 23 NAT of the energetic particles during the ground level enhancement (GLE) events of Solar Cycle 23. We find that the GLE particles are released when the CMEs reach an average heliocentric distance of ~3.6 solar radii (Rs

Usoskin, Ilya G.

77

First time nuclear material detection by one short-pulse-laser-driven neutron  

E-print Network

- 1 - First time nuclear material detection by one short-pulse-laser-driven neutron source April 3, 2013 First Time Nuclear Material Detection by One Short- Pulse-Laser-Driven Neutron Source In a set processes yield delayed neutrons). The detection system consisted of two identical neutron detector well

Kurien, Susan

78

Evolution of Geomagnetic Cutoff Rigidities on Short-and Long-term Time Scales  

Microsoft Academic Search

The magnetic shielding of the Earth from galactic and solar cosmic radiation is dependent on the magnitude and orientation of the Earth's magnetic field. The amount of shielding at a specific location is defined by the geomagnetic cutoff rigidity (RC), which varies on both short- and long-term time scales. On short time scales, the amount of geomagnetic shielding at any

D. F. Smart; M. A. Shea; N. Lifton

2008-01-01

79

“Sometimes” and “not never” revisited: on branching versus linear time temporal logic  

Microsoft Academic Search

The differences between and appropriateness of branching versus linear time temporal logic for reasoning about concurrent programs are studied. These issues have been previously considered by Lamport. To facilitate a careful examination of these issues, a language, CTL*, in which a universal or existential path quantifier can prefix an arbitrary linear time assertion, is defined. The expressive power of a

E. Allen Emerson; Joseph Y. Halpern

1986-01-01

80

Short-Time Annealing Characteristics of Electrical Conductors  

Microsoft Academic Search

Loss in strength is a function of conductor maximum temperature which, itself, is a function of I2t. Instead of producing currents and times as they may occur in the field, one can, in the laboratory, choose more convenient values giving the same I2t, the same maximum temperature and the same loss in strength. Using this approach, diagrams were developed showing,

L. F. Roehmann; Earl Hazan

1963-01-01

81

A Thermal Analysis for Photovoltaic System at Short Time Interval  

Microsoft Academic Search

However PV array temperature and ambient temperature changes every seconds, previous irradiation and temperature influence the current array temperature. However many paper described the model which estimate PV module temperature is static and hourly value. We have established an experimental equipment and monitor to the temperature on the second time interval scale. This paper presents to estimate fluctuation of PV

Hiroshi Matsukawa; Hirotaka Koizumi; Kosuke Kurokawa

82

Nutrient timing revisited: is there a post-exercise anabolic window?  

PubMed

Nutrient timing is a popular nutritional strategy that involves the consumption of combinations of nutrients--primarily protein and carbohydrate--in and around an exercise session. Some have claimed that this approach can produce dramatic improvements in body composition. It has even been postulated that the timing of nutritional consumption may be more important than the absolute daily intake of nutrients. The post-exercise period is widely considered the most critical part of nutrient timing. Theoretically, consuming the proper ratio of nutrients during this time not only initiates the rebuilding of damaged muscle tissue and restoration of energy reserves, but it Does So in a supercompensated fashion that enhances both body composition and exercise performance. Several researchers have made reference to an anabolic "window of opportunity" whereby a limited time exists after training to optimize training-related muscular adaptations. However, the importance - and even the existence - of a post-exercise 'window' can vary according to a number of factors. Not only is nutrient timing research open to question in terms of applicability, but recent evidence has directly challenged the classical view of the relevance of post-exercise nutritional intake with respect to anabolism. Therefore, the purpose of this paper will be twofold: 1) to review the existing literature on the effects of nutrient timing with respect to post-exercise muscular adaptations, and; 2) to draw relevant conclusions that allow practical, evidence-based nutritional recommendations to be made for maximizing the anabolic response to exercise. PMID:23360586

Aragon, Alan Albert; Schoenfeld, Brad Jon

2013-01-01

83

Nutrient timing revisited: is there a post-exercise anabolic window?  

PubMed Central

Nutrient timing is a popular nutritional strategy that involves the consumption of combinations of nutrients--primarily protein and carbohydrate--in and around an exercise session. Some have claimed that this approach can produce dramatic improvements in body composition. It has even been postulated that the timing of nutritional consumption may be more important than the absolute daily intake of nutrients. The post-exercise period is widely considered the most critical part of nutrient timing. Theoretically, consuming the proper ratio of nutrients during this time not only initiates the rebuilding of damaged muscle tissue and restoration of energy reserves, but it does so in a supercompensated fashion that enhances both body composition and exercise performance. Several researchers have made reference to an anabolic “window of opportunity” whereby a limited time exists after training to optimize training-related muscular adaptations. However, the importance - and even the existence - of a post-exercise ‘window’ can vary according to a number of factors. Not only is nutrient timing research open to question in terms of applicability, but recent evidence has directly challenged the classical view of the relevance of post-exercise nutritional intake with respect to anabolism. Therefore, the purpose of this paper will be twofold: 1) to review the existing literature on the effects of nutrient timing with respect to post-exercise muscular adaptations, and; 2) to draw relevant conclusions that allow practical, evidence-based nutritional recommendations to be made for maximizing the anabolic response to exercise. PMID:23360586

2013-01-01

84

Time-resolved photoelectron emission from atoms and surfaces: the photoeffect revisited  

NASA Astrophysics Data System (ADS)

Streaking spectroscopy experiments enable the resolution in time of photo-ionization processes at the natural time scale (tens of attoseconds, 1 as = 10-18 seconds) of the motion of valence electrons in atoms and solids. This ultrahigh time resolution allows the observation of an apparent ``delay-time'' difference between the release and detection of photoelectrons from different initial states of atoms and solids. These delays are typically of the order of tens of attoseconds and are a measure of the net quantum phase that is accumulated during the entire photoemission process, including the release, propagation, and detection of the photoelectron. I will discuss different interpretations of and contributions to photoemission delay times based on the comparison of calculated time-resolved photo-electron spectra with recent experiments [1,2]. In particular, for time-resolved photo-emission from metal surfaces [3,4], we find our calculated electron spectra to be very sensitive to details in the modeling of dielectric-response and electron-propagation effects during the laser-assisted XUV excitation and emission process [5]. The sensitivity of photoemission time delays to the plasmonic response of solid surfaces suggests the time-resolved observation of collective (plasmonic, excitonic, etc.) excitations in atoms, nano-particles, and solids. [4pt] [1] C.-H. Zhang and U. Thumm, Phys. Rev. A 82, 043405 (2010);[0pt] [2] Phys. Rev. A 84, 033401 (2011);[0pt] [3] Phys. Rev. Lett. 102, 123601 (2009);[0pt] [4] Phys. Rev. A 84, 065403 (2011);[0pt] [5] Phys. Rev. A 84, 063403 (2011).

Thumm, Uwe

2012-06-01

85

The time-dependent quantum harmonic oscillator revisited: Applications to quantum field theory  

SciTech Connect

In this article, we formulate the study of the unitary time evolution of systems consisting of an infinite number of uncoupled time-dependent harmonic oscillators in mathematically rigorous terms. We base this analysis on the theory of a single one-dimensional time-dependent oscillator, for which we first summarize some basic results concerning the unitary implementability of the dynamics. This is done by employing techniques different from those used so far to derive the Feynman propagator. In particular, we calculate the transition amplitudes for the usual harmonic oscillator eigenstates and define suitable semiclassical states for some physically relevant models. We then explore the possible extension of this study to infinite dimensional dynamical systems. Specifically, we construct Schroedinger functional representations in terms of appropriate probability spaces, analyze the unitarity of the time evolution, and probe the existence of semiclassical states for a wide range of physical systems, particularly, the well-known Minkowskian free scalar fields and Gowdy cosmological models.

Gomez Vergel, Daniel [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain)], E-mail: dgvergel@iem.cfmac.csic.es; Villasenor, Eduardo J.S. [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Grupo de Modelizacion y Simulacion Numerica, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes (Spain)], E-mail: ejsanche@math.uc3m.es

2009-06-15

86

Robust digital control of systems with time delay (the Smith predictor revisited)  

Microsoft Academic Search

The design of robust digital controllers for systems with time delay is investigated. A particular class of digital controller is considered, namely those for which the closed-loop poles include the poles of the system to be controlled. Robust design with respect to time delay variations requires the introduction of additional closed-loop poles and\\/or reduction of the gain of the feedback

I. D. LANDAU

1995-01-01

87

Short-time critical dynamics at perfect and imperfect surfaces.  

PubMed

With Monte Carlo simulations, we study the dynamic relaxation at perfect and imperfect surfaces of the three-dimensional Ising model with an ordered initial state. The time evolution of the surface magnetization, the line magnetization of the defect line, and the corresponding susceptibilities and second cumulants is carefully examined. Universal dynamic scaling forms including a dynamic crossover scaling form are identified at the ordinary, special, and surface phase transitions. The critical exponents beta1 of the surface magnetization and beta2 of the line magnetization are extracted. The impact of the defect line on the universality classes is investigated. PMID:18763939

Lin, S Z; Zheng, B

2008-07-01

88

Estimating Mean First Passage Time of Biased Random Walks with Short Relaxation Time on Complex Networks  

PubMed Central

Biased random walk has been studied extensively over the past decade especially in the transport and communication networks communities. The mean first passage time (MFPT) of a biased random walk is an important performance indicator in those domains. While the fundamental matrix approach gives precise solution to MFPT, the computation is expensive and the solution lacks interpretability. Other approaches based on the Mean Field Theory relate MFPT to the node degree alone. However, nodes with the same degree may have very different local weight distribution, which may result in vastly different MFPT. We derive an approximate bound to the MFPT of biased random walk with short relaxation time on complex network where the biases are controlled by arbitrarily assigned node weights. We show that the MFPT of a node in this general case is closely related to not only its node degree, but also its local weight distribution. The MFPTs obtained from computer simulations also agree with the new theoretical analysis. Our result enables fast estimation of MFPT, which is useful especially to differentiate between nodes that have very different local node weight distribution even though they share the same node degrees. PMID:24699325

Lee, Zhuo Qi; Hsu, Wen-Jing; Lin, Miao

2014-01-01

89

The short-time spectrum analysis of real-time sampling speech with DSP TMS320VC5416 chip  

NASA Astrophysics Data System (ADS)

For automatic speech recognition (ASR), the research centers mainly on algorithm of improving robust, researchers put less emphasis on realization and application of better speech algorithm. Real-time proceeding of speech recognition directly influence on its application, so real-time proceeding of speech recognition is as important as study of algorithm. Speech transform domain method is a necessary technique of speech recognition, so real-time analysis of transform domain method is necessary. In transform domain methods, the short-time spectrum analysis is simple and easy to realize, especially the short-time FFT algorithm is applied to the short-time spectrum analysis. FFT algorithm reduces multiplications greatly. For the purpose, this paper presents short-time spectrum analysis of real-time sampling speech based on FFT algorithm. We use DSP TMS320VC5416 chip and speech codec ASIC TLV320AIC23 as hardware, the real-time speech signal is acquired by ASIC TLV320AIC23. When working frequency of TMS320VC5416 is set 160 MHz and sampling frequency is 44.1 kHz, the short-time FFT is radix-2 DIF-FFT algorithm and the length of short-time window is 128, the simulation waves and data show that the short-time FFT algorithm analysis based on TMS320VC5416 chip can meet real-time of system. For estimation of proceeding error, we make a calculation of radix- 2 DIT-IFFT. Comparing the result of DIT-IFFT and sampling speech data, error is less than 10-3.

Fan, Qinru; Ren, Wen-hua

2013-07-01

90

Long and short time quantum dynamics: III. Transients  

NASA Astrophysics Data System (ADS)

The quantum transport equations for fast transients have the structure of a Generalized Master Equations for the single-particle distribution, with causal memory terms. Nonequilibrium Green's functions are reduced to GME if the Generalized Kadanoff-Baym Ansatz is applied. This Ansatz has been used with success both to non-linear transport and to optical transients in semi-conductors; further progress is linked with its extension to a family of the Causal Ansatzes, differing primarily in renormalization of the propagators. For the switch-on non-equilibrium states, generated by a perturbation from equilibrium, the renormalization to the dark dressed Green's function followed by calculation of the induced self-energies is a productive direction. It also circumvents the problem of correlated initial conditions, far from a general solution otherwise. Such initial conditions appear as incompatible with a Causal Ansatz in general. The presently available formalism permits to study a transient process in the whole time range using the complete NGF, but making a flexible Ansatz-based reduction appropriate to the stage of dynamic evolution.

Špi?ka, Václav; Velický, Bed?ich; Kalvová, And?la

2005-10-01

91

Hate networks revisited: time and user interface dependence study of user emotions in political forum  

E-print Network

The paper presents analysis of time evolution within am Internet political forum, characterized by large political differences and high levels of emotions. The study compares samples of discussions gathered at three periods separated by important events. We focus on statistical aspects related to emotional content of communication and changes brought by technologies that increase or decrease the direct one-to-one discussions. We discuss implications of user interface aspects on promoting communication across a political divide.

Sobkowicz, Pawel

2011-01-01

92

Blankenbach 3 revisited: intricate time-dependent patterns in a simple model of mantle convection  

NASA Astrophysics Data System (ADS)

We evaluate time-dependent nature of mantle convection using a simple 2D Cartesian model with internal heating based on the benchmark case 3 in Blankenbach et al. (Geophysical Journal International, 1989). We are particularly interested in the bifurcation patterns of the Vrms-Nu phase plot for Rayleigh numbers (Ra) around the benchmark value (Ra = 2.16×105), but more information is disclosed when we go to higher Ra (up to 8×105). We also investigate the role of the boundary conditions, for which we change to periodic boundary conditions for a second bifurcation study. We find an intricate pattern in the behavior of the heat flow (as measured by the Nusselt number Nu(t)) and the kinetic energy (as measured by Vrms(t)) which include period doubling, break down of periodic into episodic flow and reorganization into periodic flow at higher Ra. Two patterns of bifurcation are found. One is the period doubling pattern, described in Blankenbach et al. 1989 and referred to as P2-P4 bifurcation. The period doubling results from the differentiation of existing limit points of the time series of Nu or Vrms. The other pattern is period-preserving, which is found at higher Ra number in this study. In the period-preserving bifurcation, the new limit points (peak and valley) of the Nu and Vrms time series showed up as a twist in the monotonic intervals between a peak and valley. In this case the period doesn’t change. Both of the two patterns are observed in the models with the two types of boundary conditions (reflective and periodic). At a given Ra, different solutions can be obtained with different initial conditions. The initial condition is usually a solution with its Ra in the neighborhood, and with this neighborhood searching method, we were able to span the bifurcation plot (Ra-limit points of Nu(t) or Vrms(t)) to the range of Ra = 1×105~8×105 with both two boundary conditions. In this process, hysteresis is observed as expected in dynamic system, and the overlap of different trend of solutions are large enough to demonstrate tough competition between them. Limit points of Vrms time series obtained at same conditions with Blanckenbach case 3 with different Rayleigh numbers, showing bifurcation.

Hu, Z.; van Keken, P. E.

2010-12-01

93

Residence time and collision statistics for exponential flights: The rod problem revisited  

NASA Astrophysics Data System (ADS)

Many random transport phenomena, such as radiation propagation, chemical-biological species migration, or electron motion, can be described in terms of particles performing exponential flights. For such processes, we sketch a general approach (based on the Feynman-Kac formalism) that is amenable to explicit expressions for the moments of the number of collisions and the residence time that the walker spends in a given volume as a function of the particle equilibrium distribution. We then illustrate the proposed method in the case of the so-called rod problem (a one-dimensional system), and discuss the relevance of the obtained results in the context of Monte Carlo estimators.

Zoia, A.; Dumonteil, E.; Mazzolo, A.

2011-08-01

94

VARIABILITY OF SOLAR RADIATION DATA OVER SHORT TIME INTERVALS Frank Vignola  

E-print Network

VARIABILITY OF SOLAR RADIATION DATA OVER SHORT TIME INTERVALS Frank Vignola Department of Physics ra- diation. This article examines at the variability of beam and global solar radiation over short solar radiation values with ground-based data. 1. INTRODUCTION It is difficult to evaluate solar

Oregon, University of

95

Circinus X-1 revisited: Fast-timing properties in relation to spectral state  

NASA Technical Reports Server (NTRS)

We have studied the X-ray spectral and fast-timing variations of Cir X-1 by performing a homogenous analysis of all EXOSAT ME data on this source using X-ray hardness-intensity diagrams (HIDs), color-color diagrams (CDs), and power spectra. Cir X-1 exhibits a wide range of power spectral shapes and a large variety in X-ray spectral shapes. At different epochs the power spectra variously resemble those of an atoll source, a Z source, a black-hole candidate, or are unlike any of these. At some epochs one-dimensional connected-branch patterns are seen in HID and CD, and at other times more complex structures are found. We interpret the complex behavior of Cir X-1 in terms of a model where accretion rate, orbital phase and epoch are the main determinants of the source behavior, and where the unique properties of the source are due to two special circumstances: (1) the source is the only known atoll source (accreting neutron star with a very low magnetic field) that can reach the Eddington critical accretion rate, and (2) it has a unique, highly eccentric and probably precessing orbit. Property (1) makes Cir X-1 a very important source for our understanding of the similarities in the observable properties of neutron stars and black holes as it allows to separate out black hole signatures from properties that are merely due to the presence of accretion compact with a low magnetic field.

Oosterbroek, T.; Van Der Klis, M.; Kuulkers, E.; Van Paradijs, J.; Lewin, W. H. G.

1995-01-01

96

The late-time tails in the Reissner-Nordstr"om spacetime revisited  

NASA Astrophysics Data System (ADS)

The late-time tail problem in the Reissner-Nordstr"om (RN) spacetime is dual to a tail problem in the Schwarzschild spacetime with a different initial data set: At a fixed observation point the asymptotic decay rate of the fields are equal. This duality is used to find the decay rate for tails in RN. This decay rate is exactly as in Schwarzschild, including the case of the extremely-charged RN spacetime (ERN). The only case where any deviation from the Schwarzschild decay rate is found is the case of the tails along the event horizon of an ERN spacetime, where the decay rate is the same as at future null infinity. As observed at a fixed location, the decay rate in ERN is the same as in Schwarzschild. We verify these results with numerical simulations.

Blaksley, Carl J.; Burko, Lior M.

2007-11-01

97

Late-time tails in the Reissner-Nordström spacetime revisited  

NASA Astrophysics Data System (ADS)

We propose that the late-time tail problem in the Reissner-Nordström (RN) spacetime is dual to a tail problem in the Schwarzschild spacetime with a different initial data set: at a fixed observation point the asymptotic decay rate of the fields are equal. This duality is used to find the decay rate for tails in RN. This decay rate is exactly as in Schwarzschild, including the case of the extremely-charged RN spacetime (ERN). The only case where any deviation from the Schwarzschild decay rate is found is the case of the tails along the event horizon of an ERN spacetime, where the decay rate is the same as at future null infinity. As observed at a fixed location, the decay rate in ERN is the same as in Schwarzschild. We verify these expectations with numerical simulations.

Blaksley, Carl J.; Burko, Lior M.

2007-11-01

98

The late-time tails in the Reissner-Nordström spacetime revisited  

E-print Network

We propose that the late-time tail problem in the Reissner-Nordstr\\"{o}m (RN) spacetime is dual to a tail problem in the Schwarzschild spacetime with a different initial data set: at a fixed observation point the asymptotic decay rate of the fields are equal. This duality is used to find the decay rate for tails in RN. This decay rate is exactly as in Schwarzschild, including the case of the extremely-charged RN spacetime (ERN). The only case where any deviation from the Schwarzschild decay rate is found is the case of the tails along the event horizon of an ERN spacetime, where the decay rate is the same as at future null infinity. As observed at a fixed location, the decay rate in ERN is the same as in Schwarzschild. We verify these expectations with numerical simulations.

Carl J. Blaksley; Lior M. Burko

2007-10-15

99

Linear and synchrosqueezed time-frequency representations revisited. Part II: Resolution, reconstruction and concentration  

E-print Network

Having reviewed the aspects of the linear and synchrosqueezed time-frequency representations (TFRs) needed for their understanding and correct use in Part I of this review, we now consider three more subtle issues that are nonetheless of crucial importance for effective application of these methods. (i) What effect do the window/wavelet parameters have on the resultant TFR, and how can they most appropriately be chosen? (ii) What are the errors inherent in the two reconstruction methods (direct and ridge) and which of them is the better? (iii) What are the advantages and drawbacks associated with synchrosqueezing? To answer these questions, we perform a detailed numerical and theoretical study of the TFRs under consideration. We consider the relevant estimates in the presence of the complications that arise in practical applications including interference between components, amplitude modulation, frequency modulation, and noise. Taken together, the results provide an in-depth understanding of the issues in qu...

Iatsenko, Dmytro; Stefanovska, Aneta

2013-01-01

100

The effects of time, luminance, and high contrast targets: revisiting grating acuity in the domestic cat.  

PubMed

Based on optical clarity and retinal cone density, the cat has a potential acuity of 20-30 cycles per degree (cpd), yet most behavioral studies estimate feline acuity between 3 and 9 cpd. Those studies, however, were limited by restrictive experimental conditions that may have inadvertently lowered the estimated grating acuity. Two domestic cats previously trained on a two-choice visual discrimination task were retrained on a grating detection/discrimination task with unlimited time, high luminance, high contrast targets, and adequate space to prevent poor accommodation from affecting the results. Initially, vertical gratings of increasing cpd were tested until failure. Then, horizontal gratings of increasing cpd were tested until failure. Finally, the finest horizontal grating resolved was confirmed with a third test requiring 24 correct out of 36 consecutive trials, yielding a binomial probability less than 0.02 of non-random occurrence. M1, a 7-year-old male gray tabby with +2.00 OU refraction, tested for a grating detection acuity of 15 cpd for both vertical and horizontal gratings (binomial probability = 0.009). F1, a 2-year-old female gray tabby with +0.25 OU refraction, tested for a grating orientation discrimination acuity of 20 cpd for both vertical and horizontal gratings (binomial probability = 0.004). These results demonstrate that a young cat with good focus is capable of discriminating 20 cpd, in close agreement with the physiologic maximum. Uncorrected focusing errors appear to degrade visual performance. Optimum experimental conditions resulted in better grating acuity measurements than previously reported, emphasizing the importance of environmental factors in feline behavioral testing. PMID:23978601

Clark, Daria L; Clark, Robert A

2013-11-01

101

Thermal Casimir effect for rectangular cavities inside (D+1)-dimensional Minkowski space-time revisited  

NASA Astrophysics Data System (ADS)

We reconsider the thermal scalar Casimir effect for p-dimensional rectangular cavity inside (D+1)-dimensional Minkowski space-time and clarify the ambiguity in the regularization of the temperature-dependent part of the free energy. We derive rigorously the regularization of the temperature-dependent part of the free energy by making use of the Abel-Plana formula repeatedly and get the explicit expression of the terms to be subtracted. In the cases of D = 3, p = 1 and D = 3, p = 3, we precisely recover the results of parallel plates and three-dimensional box in the literature. Furthermore, for D>p and D = p cases with periodic, Dirichlet and Neumann boundary conditions, we give the explicit expressions of the Casimir free energy in both low temperature (small separations) and high temperature (large separations) regimes, through which the asymptotic behavior of the free energy changing with temperature and the side length is easy to see. We find that for D>p, with the side length going to infinity, the Casimir free energy tends to positive or negative constants or zero, depending on the boundary conditions. But for D = p, the leading term of the Casimir free energy for all three boundary conditions is a logarithmic function of the side length. We also discuss the thermal Casimir force changing with temperature and the side length in different cases and find that when the side length goes to infinity, the force always tends to be zero for different boundary conditions regardless of D>p or D = p. The Casimir free energy and force at high temperature limit behave asymptotically alike that they are proportional to the temperature, be they positive (repulsive) or negative (attractive) in different cases. Our study may be helpful in providing a comprehensive and complete understanding of this old problem.

Lin, Rui-Hui; Zhai, Xiang-Hua

2014-03-01

102

Filament-Based Atmospheric Dispersion Model to Achieve Short Time-Scale Structure of Odor Plumes.  

National Technical Information Service (NTIS)

This article presents the theoretical motivation, implementation approach, and example validation results for a computationally efficient plume simulation model, designed to replicate both the short-term time signature and long-term exposure statistics of...

J. A. Farrell, J. Murlis, X. Long, W. Li R. Carde

2002-01-01

103

Revisiting Lasswell  

Microsoft Academic Search

This article continues the line of argument and historical interpretation we offered in “The Policy Scientist of Democracy:\\u000a The Discipline of Harold D. Lasswell” by way of a response to Ronald Brunner’s “The Policy Scientist of Democracy Revisited.”\\u000a Problems regarding Lasswell’s capacious vision of the policy scientist and vagaries surrounding “democracy,” do not diminish\\u000a the importance of the questions Lasswell

James Farr; Jacob S. Hacker; Nicole Kazee

2008-01-01

104

Prediction of Long and Short Time Rheological Behavior in Soft Glassy Materials  

NASA Astrophysics Data System (ADS)

We present an effective time approach to predict long and short time rheological behavior of soft glassy materials from experiments carried out over practical time scales. Effective time approach takes advantage of relaxation time dependence on aging time that allows time-aging time superposition even when aging occurs over the experimental time scales. Interestingly, experiments on a variety of soft materials demonstrate that the effective time approach successfully predicts superposition for diverse aging regimes ranging from subaging to hyperaging behaviors. This approach can also be used to predict behavior of any response function in molecular as well as spin glasses.

Shahin, A.; Joshi, Yogesh M.

2011-01-01

105

Coal liquefaction short residence time process research. Second quarterly report, January 1March 31, 1979  

Microsoft Academic Search

Process research on short residence time studies includes kinetic studies on a bench scale reactor, residence time studies in the three phase liquefaction systems, and characterization of the initial chemical processes. Failures of electrical heaters and a new compressor prevented operation of the reactor in the last quarter. A detector system for measuring the residence time of solids has been

R. K. Traeger; T. C. Bickel

1979-01-01

106

Integrating random matrix theory predictions with short-time dynamical effects in chaotic systems  

NASA Astrophysics Data System (ADS)

We discuss a modification to random matrix theory eigenstate statistics that systematically takes into account the nonuniversal short-time behavior of chaotic systems. The method avoids diagonalization of the Hamiltonian; instead it requires only knowledge of short-time dynamics for a chaotic system or ensemble of similar systems. Standard random matrix theory and semiclassical predictions are recovered in the limits of zero Ehrenfest time and infinite Heisenberg time, respectively. As examples, we discuss wave-function autocorrelations and cross correlations, and show that significant improvement in accuracy is obtained for simple chaotic systems where comparison can be made with brute-force diagonalization. The accuracy of the method persists even when the short-time dynamics of the system or ensemble is known only in a classical approximation. Further improvement in the rate of convergence is obtained when the method is combined with the correlation function bootstrapping approach introduced previously.

Smith, A. Matthew; Kaplan, Lev

2010-07-01

107

Real-time mobile customer short message system design and implementation  

NASA Astrophysics Data System (ADS)

To expand the current mobile phone short message service, and to make the contact between schools, teachers, parents and feedback of the modern school office system more timely and conveniently, designed and developed the Short Message System based on the Linux platform. The state-of-the-art principles and designed proposals in the Short Message System based on the Linux platform are introduced. Finally we propose an optimized secure access authentication method. At present, many schools,vbusinesses and research institutions ratify the promotion and application the messaging system gradually, which has shown benign market prospects.

Han, Qirui; Sun, Fang

108

Multivariate Short-Term Traffic Flow Forecasting Using Time-Series Analysis  

Microsoft Academic Search

Existing time-series models that are used for short-term traffic condition forecasting are mostly univariate in nature. Generally, the extension of existing univariate time-series models to a multivariate regime involves huge computational complexities. A different class of time-series models called structural time-series model (STM) (in its multivariate form) has been introduced in this paper to develop a parsimonious and computationally simple

Bidisha Ghosh; Biswajit Basu; Margaret O'Mahony

2009-01-01

109

Hierarchical structure of the energy landscape of proteins revisited by time series analysis. II. Investigation of explicit solvent effects  

NASA Astrophysics Data System (ADS)

Time series analysis tools are employed on the principal modes obtained from the C? trajectories from two independent molecular-dynamics simulations of ?-amylase inhibitor (tendamistat). Fluctuations inside an energy minimum (intraminimum motions), transitions between minima (interminimum motions), and relaxations in different hierarchical energy levels are investigated and compared with those encountered in vacuum by using different sampling window sizes and intervals. The low-frequency low-indexed mode relationship, established in vacuum, is also encountered in water, which shows the reliability of the important dynamics information offered by principal components analysis in water. It has been shown that examining a short data collection period (100 ps) may result in a high population of overdamped modes, while some of the low-frequency oscillations (<10 cm-1) can be captured in water by using a longer data collection period (1200 ps). Simultaneous analysis of short and long sampling window sizes gives the following picture of the effect of water on protein dynamics. Water makes the protein lose its memory: future conformations are less dependent on previous conformations due to the lowering of energy barriers in hierarchical levels of the energy landscape. In short-time dynamics (<10 ps), damping factors extracted from time series model parameters are lowered. For tendamistat, the friction coefficient in the Langevin equation is found to be around 40-60 cm-1 for the low-indexed modes, compatible with literature. The fact that water has increased the friction and that on the other hand has lubrication effect at first sight contradicts. However, this comes about because water enhances the transitions between minima and forces the protein to reduce its already inherent inability to maintain oscillations observed in vacuum. Some of the frequencies lower than 10 cm-1 are found to be overdamped, while those higher than 20 cm-1 are slightly increased. As for the long-time dynamics in water, it is found that random-walk motion is maintained for approximately 200 ps (about five times of that in vacuum) in the low-indexed modes, showing the lowering of energy barriers between the higher-level minima.

Alakent, Burak; Camurdan, Mehmet C.; Doruker, Pemra

2005-10-01

110

Hierarchical structure of the energy landscape of proteins revisited by time series analysis. II. Investigation of explicit solvent effects.  

PubMed

Time series analysis tools are employed on the principal modes obtained from the C(alpha) trajectories from two independent molecular-dynamics simulations of alpha-amylase inhibitor (tendamistat). Fluctuations inside an energy minimum (intraminimum motions), transitions between minima (interminimum motions), and relaxations in different hierarchical energy levels are investigated and compared with those encountered in vacuum by using different sampling window sizes and intervals. The low-frequency low-indexed mode relationship, established in vacuum, is also encountered in water, which shows the reliability of the important dynamics information offered by principal components analysis in water. It has been shown that examining a short data collection period (100 ps) may result in a high population of overdamped modes, while some of the low-frequency oscillations (<10 cm(-1)) can be captured in water by using a longer data collection period (1200 ps). Simultaneous analysis of short and long sampling window sizes gives the following picture of the effect of water on protein dynamics. Water makes the protein lose its memory: future conformations are less dependent on previous conformations due to the lowering of energy barriers in hierarchical levels of the energy landscape. In short-time dynamics (<10 ps), damping factors extracted from time series model parameters are lowered. For tendamistat, the friction coefficient in the Langevin equation is found to be around 40-60 cm(-1) for the low-indexed modes, compatible with literature. The fact that water has increased the friction and that on the other hand has lubrication effect at first sight contradicts. However, this comes about because water enhances the transitions between minima and forces the protein to reduce its already inherent inability to maintain oscillations observed in vacuum. Some of the frequencies lower than 10 cm(-1) are found to be overdamped, while those higher than 20 cm(-1) are slightly increased. As for the long-time dynamics in water, it is found that random-walk motion is maintained for approximately 200 ps (about five times of that in vacuum) in the low-indexed modes, showing the lowering of energy barriers between the higher-level minima. PMID:16238428

Alakent, Burak; Camurdan, Mehmet C; Doruker, Pemra

2005-10-01

111

Divergence in perpendicular recurrence plot; quantification of dynamical divergence from short chaotic time series  

Microsoft Academic Search

A new toolkit, divergence in perpendicular recurrence plot (DPRP), which can roughly reflect the largest Lyapunov exponent (LLE), is proposed to consider a dynamical divergence of attractor reconstructed from very short time series. This method is tested respectively with the stationary and the nonstationary time series generated from the Lorenz system.

J. M. Choi; B. H. Bae; S. Y. Kim

1999-01-01

112

Effect of squeezing and Planck constant dependence in short time semiclassical entanglement  

NASA Astrophysics Data System (ADS)

In this paper, we investigate into the short time semiclassical entanglement of a general class of two-coupled harmonic oscillator system that includes additional nonlinear terms in the potential of the form ? x m y n , such that the sum of the degree m and n equals to a fixed constant. An analytical expression of the short time linear entropy is derived and it shows a clear relationship between the single mode squeezing and the entanglement dynamics. In addition to that, our theoretical analysis has shown that the short time semiclassical entanglement entropy displays a dependence on the Planck constant ? of the form ? m + n - 2 for this class of systems. By applying our results to the linearly coupled harmonic oscillator, the Barbanis-Contopoulos, the Hénon-Heiles and the Pullen-Edmonds Hamiltonian, we have found a good correspondence between the numerical and analytical results in the short-time regime. Interestingly, our results have demonstrated both analytically and numerically that an appropriate manipulation of initial squeezing can have the significant effect of enhancing the short time semiclassical entanglement between the two subsystems.

Joseph, Sijo K.; Chew, Lock Yue; Sanjuan, Miguel A. F.

2014-08-01

113

Short-time growth of a Kardar-Parisi-Zhang interface with flat initial conditions.  

PubMed

The short-time behavior of the (1+1)-dimensional Kardar-Parisi-Zhang (KPZ) growth equation with a flat initial condition is obtained from the exact expressions for the moments of the partition function of a directed polymer with one end point free and the other fixed. From these expressions, the short-time expansions of the lowest cumulants of the KPZ height field are exactly derived. The results for these two classes of cumulants are checked in high-precision lattice numerical simulations. The short-time limit considered here is relevant for the study of the interface growth in the large-diffusivity or weak-noise limit and describes the universal crossover between the Edwards-Wilkinson and the KPZ universality classes for an initially flat interface. PMID:23214573

Gueudré, Thomas; Le Doussal, Pierre; Rosso, Alberto; Henry, Adrien; Calabrese, Pasquale

2012-10-01

114

Detection systems for short-time stroboscopic neutron imaging and measurements on a rotating engine  

Microsoft Academic Search

Today's neutron sources do not deliver sufficient flux to examine singular short-time events in the millisecond range by neutron radiography.However, periodic processes can be examined if a triggered accumulating detector collects information of identical time-windows and positions over several cycles of the process. The same problem applies if the source signal itself carries information, like the energy–time dependence in the

B. Schillinger; H. Abele; J. Brunner; G. Frei; R. Gähler; A. Gildemeister; A. Hillenbach; E. Lehmann; P. Vontobel

2005-01-01

115

Dispersion curves from short-time molecular dynamics simulation. 1. Diatomic chain results  

SciTech Connect

The multiple signal classification method (MUSIC) for frequency estimation is used to compute the frequency dispersion curves of a diatomic chain from the time-dependent structure factor. In this paper, the authors demonstrate that MUSIC can accurately determine the frequencies from very short time trajectories. MUSIC is also used to show how the frequencies can vary in time, i.e., along a trajectory. The method is ideally suited for analyzing molecular dynamics simulations of large systems.

Noid, D.W.; Broocks, B.T.; Gray, S.K.; Marple, S.L.

1988-06-16

116

Is correlation dimension a reliable indicator of low-dimensional chaos in short hydrological time series?  

NASA Astrophysics Data System (ADS)

The reliability of the correlation dimension estimation in short hydrological time series is investigated using an inverse approach. According to this approach, first predictions are made using the phase-space reconstruction technique and the artificial neural networks. The correlation dimension is estimated next independently and is compared with the prediction results. A short hydrological series, monthly runoff series of 48 years (with a total of only 576 values) observed at the Coaracy Nunes/Araguari River watershed in northern Brazil, is studied. The correlation dimension results are in reasonably good agreement with the optimal embedding dimension obtained from the phase-space method and the optimal number of inputs from the neural networks. No underestimation of the correlation dimension is observed due to the small data size, rather there seems to be a slight overestimation due to the presence of noise in the data. The results indicate that the accuracy of the correlation dimension may not be judged on the basis of the length of the time series but on whether the time series is long enough to reasonably represent the dynamical changes in the system. Such an observation suggests that the correlation dimension could indeed be a reliable indicator of low-dimensional chaos even in short hydrological time series, which is certainly encouraging news for hydrologists who often have to deal with short time series.

Sivakumar, Bellie; Persson, Magnus; Berndtsson, Ronny; Uvo, Cintia Bertacchi

2002-02-01

117

Signal detection for frequency-shift keying via short-time stochastic resonance  

NASA Astrophysics Data System (ADS)

A series of short-time stochastic resonance (SR) phenomena, realized in a bistable receiver, can be utilized to detect a train of information represented by signals that adopt frequency-shift keying (FSK). It is demonstrated that the values of noise intensity at resonance regions are close for adjacent periodic signals with an appropriate frequency separation. This establishes the possibility of decoding subthreshold or slightly suprathreshold M-ary FSK signals in bistable receivers. Furthermore, the mechanism of FSK signal detection via short-time SR effects is elucidated in terms of the receiver response speed. This phenomenon provides a possible mechanism for information processing in a bistable device operating in nonstationary noisy environments, where even the inputs appear over a short timescale or have a frequency shift.

Duan, Fabing; Abbott, Derek

2005-09-01

118

Experiencing Experimental Mathematics In the short time since the first edition of Mathematics  

E-print Network

Experiencing Experimental Mathematics In the short time since the first edition of Mathematics by Experiment: Plausible Reasoning in the 21st Century and Experimentation in Mathematics: Computational Paths mathematical formula or expression. 978-1-56881-283-0; CD; $49.00 Experiments in Mathematics (CD) Jonathan M

Borwein, Jonathan

119

Lay-Offs and Short-Time Working in Selected OECD Countries.  

ERIC Educational Resources Information Center

This report, which includes the conclusions of the Organisation for Economic Cooperation and Development (OECD) Working Party on Employment and Unemployment Statistics, analyzes arrangements for compensating workers in the OECD countries who are temporarily laid-off or subject to short-time work. In introductory sections to part 1, the concepts of…

Grais, Bernard; And Others

120

Effects of short solids retention time on microbial community in a membrane bioreactor  

Microsoft Academic Search

Effects of operating lab-scale nitrifying membrane bioreactors (MBR) at short solids retention times (SRT=3, 5 and 10d) were presented with focus on reactor performance and microbial community composition. The process was capable of achieving over 87% removal of ammonia and 95% removal of chemical oxygen demand (COD), almost regardless of SRT. The denaturing gradient gel electrophoresis (DGGE) analysis shown that

Liang Duan; Ivan Moreno-Andrade; Chun-lin Huang; Siqing Xia; Slawomir W. Hermanowicz

2009-01-01

121

Large volume recycling of oceanic lithosphere over short time scales: geochemical constraints from the Caribbean Large  

E-print Network

Large volume recycling of oceanic lithosphere over short time scales: geochemical constraints from with derivation from recycled oceanic crust, while the depleted lavas are derived from a highly residual source source mantle could have been 9 500 Ma before CLIP formation and interpreted to reflect the recycling

Graham, David W.

122

A unified approach to short-time Fourier analysis and synthesis  

Microsoft Academic Search

Two distinct methods for synthesizing a signal from its short-time Fourier transform have previously been proposed. We call these methods the filter-bank summation (FBS) method and the overlap add (OLA) method. Each of these synthesis techniques has unique advantages and disadvantages in various applications due to the way in which the signal is reconstructed. In this paper we unify the

JONT B. ALLEN; LAWRENCE R. RABINER

1977-01-01

123

HOT CARRIER SPACE AND TIME DEPENDENT TRANSIENTS IN SHORT CHANNEL GALLIUM ARSENIDE DEVICES55  

E-print Network

HOT CARRIER SPACE AND TIME DEPENDENT TRANSIENTS IN SHORT CHANNEL GALLIUM ARSENIDE DEVICES55 Hr in gallium arsenide when the fields change temporally and spatially at a finite rate. For temporal changes gallium arsenide when f i e l d s change a t f i n i t e r a t e s and t o suggest the types

Paris-Sud XI, Université de

124

Reconstruction of a wind turbine's endured load spectrum using a short-time load measurement  

E-print Network

Reconstruction of a wind turbine's endured load spectrum using a short-time load measurement Abstract Wind turbines (WT) are normally designed for a service life (SL) of 20 years. In Germany, over safety. 1 Introduction A wind turbine (WT) is normally designed, tested and certified for a design life

Berlin,Technische Universität

125

APPARATUS FOR SHORT TIME MEASUREMENTS IN A FIXED BED, GAS/SOLID REACTOR  

EPA Science Inventory

The article describes an apparatus for the exposure of a solid to reactive process gas. he switch makes possible short time exposures (equal to or greater than 0.3 s) in a fixed-bed reactor for kinetic studies of rapid reactions....

126

Short-term solar irradiance and irradiation forecasts via different time series techniques: A preliminary study  

E-print Network

This communication is devoted to solar irradiance and irradiation short-term forecasts, which are useful for electricity production. Several different time series approaches are employed. Our results and the corresponding numerical simulations show that techniques which do not need a large amount of historical data behave better than those which need them, especially when those data are quite noisy.

Join, Cédric; Fliess, Michel; Muselli, Marc; Nivet, Marie Laure; Paoli, Christophe; Chaxel, Frédéric

2014-01-01

127

Membrane bioreactor operation at short solids retention times: performance and biomass characteristics  

Microsoft Academic Search

This study investigated the performance and biomass characteristics of a membrane bioreactor (MBR) and a completely mixed activated sludge (CMAS) system operated at short solids retention times (SRT) ranging from 0.25 to 5d and hydraulic retention times of 3 and 6h. The lab-scale reactors were fed with synthetic wastewater to ensure consistency in feed composition. Results show the MBR was

How Y. Ng; Slawomir W. Hermanowicz

2005-01-01

128

A dosimetry procedure based on storage phosphors with short fading time.  

PubMed

Problem of retrieving data on exposure to radiation from storage phosphors characterised by short fading time in unpredictably long exposure times is addressed from a numerical point of view. A simple algorithm is presented for the case of first kinetic order. Extension to a generic kinetic order is possible provided a suitable characterisation of the fading features is performed. Simulations are also presented where temperature and reading effects, as well as error measurements, are taken into account. PMID:19066251

Bernardini, A; Salis, M

2008-01-01

129

Administration Time Estimates For WAIS-R Subtests and Short Forms in a Clinical Sample  

Microsoft Academic Search

Administration times were recorded for the Wechsler Adult Intelligence Scale—Revised (WAIS-R) subtests and Verbal, Performance, and Full Scales in a sample of 50 Veterans Administration Medical Center psychiatric and neurological patients. Also calculated were the administration times required by a select group of short forms. Results indicated that a complete WAIS-R required an average of 91 minutes, 24 seconds (SD

Joseph J. Ryan; Samuel J. Rosenberg

1984-01-01

130

Short-time spectral analysis with the conventional and sliding CZT  

Microsoft Academic Search

Two sequential short-time spectral analysis techniques, amenable to nonrecursive filter implementation, are the conventional chirp-z-transform (CZT) realization of the discrete Fourier transform and the sliding CZT realization of the discrete sliding Fourier transform. This paper presents a comparative study of frame rate limitations, windowing, time and frequency resolution, spectral correlation, complexity, and inverse structures for these methods, with particular emphasis

1978-01-01

131

High-voltage and short-rise-time pulse-transformer with amorphous cores  

Microsoft Academic Search

A short rise time pulsed power transformer using cobalt-based amorphous alloy cores, which operates at high voltage (~100 kV) and high repetition rate (~4000 pps), has been developed for application as a pulsed power modulator for copper vapor lasers. An output voltage of more than 80 kV, a rise time of 65 ns and a transformation efficiency of 83% were

N. Kobayashi; N. Aoki; H. Horie; Y. Baba; Y. Sano; H. Kimura; C. Konagal

1997-01-01

132

Detection systems for short-time stroboscopic neutron imaging and measurements on a rotating engine  

NASA Astrophysics Data System (ADS)

Today's neutron sources do not deliver sufficient flux to examine singular short-time events in the millisecond range by neutron radiography. However, periodic processes can be examined if a triggered accumulating detector collects information of identical time-windows and positions over several cycles of the process. The same problem applies if the source signal itself carries information, like the energy-time dependence in the pulse of a spallation source. Several possible detection methods were considered; measurements were performed at the intense neutron beam H9 of ILL Grenoble, where an electrically driven BMW engine was examined at 1000 rpm with time resolution of 200 ?s.

Schillinger, B.; Abele, H.; Brunner, J.; Frei, G.; Gähler, R.; Gildemeister, A.; Hillenbach, A.; Lehmann, E.; Vontobel, P.

2005-04-01

133

Short-duration low-gravity experiments - Time scales, challenges and results  

NASA Technical Reports Server (NTRS)

Short-duration low-gravity experiments can be conducted either in drop tubes and drop towers, or on sounding rockets and aircraft on ballistic trajectories. While these facilities offer more frequent flight opportunities and higher cost effectiveness than orbiting spacecraft, their relatively short low-gravity times are often perceived as limiting their utility to only a narrow range of applications and research areas. In this review it is shown, based on scaling laws for diffusive transport of momentum, species and heat, radiative heat transfer and capillarity-driven motion, that with proper consideration of the characteristic length scales, a host of phenomena can be meaningfully investigated during a few seconds. This usefulness of short-duration low-gravity facilities is illustrated with numerous results of recent studies of solidification, combustion, transport in multiphase systems, statics and dynamics of liquid surfaces, magnetic Benard convection, fluid management, transport properties and the graviperception in cells.

Rosenberger, F.

1993-01-01

134

The time of onset of abnormal calcification in spondylometaepiphyseal dysplasia, short limb-abnormal calcification type.  

PubMed

A 1-month-old boy with shortness of extremities on prenatal US was referred to our department with a provisional diagnosis of achondroplasia. His height was normal but he had short extremities and platyspondyly, premature carpal epiphyses on both hands, and short tubular bones with irregular metaphyses on radiographs. Re-evaluation of the patient at the age of 1 year revealed very short height and premature calcification of the costal cartilages and epiphyses. Spondylometaepiphyseal dysplasia (SMED), short limb-abnormal calcification type was diagnosed. This condition is a very rare autosomal recessively inherited disorder, and most of the patients die in early childhood due to neurological involvement. At the age of 2 years and 5 months, a CT scan showed narrowing of the cervical spinal canal. One month later he died suddenly because of spinal cord injury. In conclusion early diagnosis is very important because the recurrence risk is high and patients may die due to early neurological complications. The time of onset of abnormal calcifications, a diagnostic finding of the disease, is at the age of around 1 year in most patients. When abnormal calcifications are not yet present, but radiological changes associated with SMED are present, this rare disease must be considered. PMID:19002453

Tüysüz, Beyhan; Gazio?lu, Nurperi; Ungür, Sava?; Aji, Dolly Yafet; Türkmen, Seval

2009-01-01

135

Long-Time Protein Folding Dynamics from Short-Time Molecular Dynamics Simulations  

Microsoft Academic Search

Protein folding involves physical timescales—microseconds to seconds—that are too long to be studied directly by straightforward molecular dynamics simulation, where the fundamental timestep is constrained to femtoseconds. Here we show how the long-time statistical dynamics of a simple solvated biomolecular system can be well described by a discrete-state Markov chain model constructed from trajectories that are an order of magnitude

John D. Chodera; William C. Swope; Jed W. Pitera; Ken A. Dill

2006-01-01

136

Tel1ATM dictates the replication timing of short yeast telomeres.  

PubMed

Telomerase action is temporally linked to DNA replication. Although yeast telomeres are normally late replicating, telomere shortening leads to early firing of subtelomeric DNA replication origins. We show that double-strand breaks flanked by short telomeric arrays cause origin firing early in S phase at late-replicating loci and that this effect on origin firing time is dependent on the Tel1(ATM) checkpoint kinase. The effect of Tel1(ATM) on telomere replication timing extends to endogenous telomeres and is stronger than that elicited by Rif1 loss. These results establish that Tel1(ATM) specifies not only the extent but also the timing of telomerase recruitment. PMID:25122631

Cooley, Carol; Davé, Anoushka; Garg, Mansi; Bianchi, Alessandro

2014-10-01

137

Pressure Distribution and Pumping Delay Time in Short-Spacing Parallel Planes  

NASA Astrophysics Data System (ADS)

The two-dimensional pressure distribution and pump-down performance between two parallel planes having a short-distance were simulated by a Monte-Carlo method, assuming the cosine-law for desorbing molecules. The distribution results were compared with those calculated by a diffusion model. The surface hitting number per molecule was also counted, and the delay time of the pumping process was evaluated by multiplying the hitting number and the surface sojourn time. The experimental observation for the delay time was compared with the calculated ones.

Saito, Yoshio; Sato, Y.; Matuda, Namio

138

Short-time Lyapunov exponent analysis and the transition to chaos in Taylor-Couette flow  

NASA Technical Reports Server (NTRS)

The physical mechanism driving the weakly chaotic Taylor-Couette flow is investigated using the short-time Liapunov exponent analysis. In this procedure, the transition from quasi-periodicity to chaos is studied using direct numerical 3D simulations of axially periodic Taylor-Couette flow, and a partial Liapunov exponent spectrum for the flow is computed by simultaneously advancing the full solution and a set of perturbations. It is shown that the short-time Liapunov exponent analysis yields more information on the exponents and dimension than that obtained from the common Liapunov exponent calculations. Results show that the chaotic state studied here is caused by a Kelvin-Helmholtz-type instability of the outflow boundary jet of Taylor vortices.

Vastano, John A.; Moser, Robert D.

1991-01-01

139

Use of short-time NH3 gas flow during Al milling  

NASA Astrophysics Data System (ADS)

Samples from mechanically alloyed aluminium powder were prepared by a simple press and sintering method in order to study the influence of a flow of ammonia gas during a short time of the milling process. All milling experiences were carried out at room temperature for a total of 10 hours. Millings were carried out in vacuum or under confined ammonia. This last type allows to incorporate nitrogen-rich second phases, mainly aluminium nitride (Al3CON) and oxynitride (Al5O6N), after powder sintering. To control the amounts of the second phases, a new milling type, using ammonia gas flow during 5 minutes followed by vacuum milling, was carried out. Testing of sintered samples shows that milling using ammonia, both confined and in flow, substantially improves mechanical properties. Furthermore, the use of a very short time gas flow allows obtaining compacts with similar tensile strength (485 MPa) to those obtained after milling in confined ammonia for 10 h.

Caballero, E. S.; Cintas, J.; Cuevas, F. G.; Montes, J. M.; Herrera-García, M.

2013-12-01

140

Short contact time direct coal liquefaction using a novel batch reactor. Quarterly report, 1996  

SciTech Connect

The objective of this research is to optimize the design and operation of the bench scale batch reactor (SCTBR) for coal liquefaction at short contact times (0.01 to 10 minutes or longer). Additional objectives are to study the kinetics of direct coal liquefaction particularly at short reaction times, and to investigate the role of the organic oxygen components of coal and their reaction pathways during liquefaction. Many of those objectives have already been achieved and others are still in progress. This quarterly report covers further progress toward those objectives. Much of the previous quarterly report was concerned mainly in the retrograde reactions occurring during the liquefaction process. This report is largely devoted to the kinetics and mechanisms of the liquefaction process itself and the influence of the liquefaction solvents.

Klein, M.T.; Calkins, W.H.; Huang, H.

1996-05-01

141

Time is short for U. S. pipelines to prepare for RFG shipments  

SciTech Connect

Time is short for US products pipelines preparing to ship reformulated gasoline (RFG) required by 1990 amendments to the Clean Air Act (CAA). As currently written, CAA final RFG rules, issued last Feb. 16 by the US Environmental Protection Agency, appear likely to upset US products pipeline logistics as never before. Operating strategies and business relationships throughout the country's refined products transportation, storage, and distribution industry will be changed. Precisely what changes are in store isn't certain because at this late date a long list regulatory, fiscal, and technical questions remain unanswered. Possibly no two companies in the chain linking US RFG and conventional gasoline supplies to retail consumers will be affected in the same way, but virtually all will be affected. The paper discusses the problems the rules have created, market disruption, operating constraints, operating constraints, coming adjustments, market imbalances, gasoline grades, and short time for preparation for compliance.

Koen, A.D.

1994-06-27

142

Using the ENF Criterion for Determining the Time of Recording of Short Digital Audio Recordings  

NASA Astrophysics Data System (ADS)

The Electric Network Frequency (ENF) Criterion is a recently developed forensic technique for determining the time of recording of digital audio recordings, by matching the ENF pattern from a questioned recording with an ENF pattern database. In this paper we discuss its inherent limitations in the case of short - i.e., less than 10 minutes in duration - digital audio recordings. We also present a matching procedure based on the correlation coefficient, as a more robust alternative to squared error matching.

Huijbregtse, Maarten; Geradts, Zeno

143

The short-time limit of the Dirichlet partition function and the image method  

E-print Network

In this paper we calculate the short-time limit of the free partition function for a diffusion process on tessellations of the n-dimensional Euclidean space $\\mathbb{E}^n, \\, n=1,2,3$ with an absorbing boundary. Utilising the method of images for domains which are compatible with finite reflection subgroups of the orthogonal group $\\mathbb{O}_n$ we recover old results from a different viewpoint and produce new ones.

Agapitos Hatzinikitas

2014-10-07

144

Fossil turbulence revisited  

E-print Network

A theory of fossil turbulence presented in the 11th Liege Colloquium on Marine turbulence is "revisited" in the 29th Liege Colloquium "Marine Turbulence Revisited". The Gibson (1980) theory applied universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as it is constrained and fossilized by buoyancy forces. Towed oceanic microstructure measurements of Schedvin (1979) confirmed the predicted universal constants. Universal constants, spectra, hydrodynamic phase diagrams (HPDs) and other predictions of the theory have been reconfirmed by a wide variety of field and laboratory observations. Fossil turbulence theory has many applications; for example, in marine biology, laboratory and field measurements suggest phytoplankton species with different swimming abilities adjust their growth strategies differently by pattern recognition of several days of turbulence-fossil-turbulence dissipation and persistence times above threshold values, signaling a developing surface layer sea change. In cosmology, self-gravitational structure masses are interpreted as fossils of primordial hydrodynamic states.

Carl H. Gibson

1999-04-19

145

Local routes revisited: the space and time dependence of the Ca2+ signal for phasic transmitter release at the rat calyx of Held  

PubMed Central

During the last decade, advances in experimental techniques and quantitative modelling have resulted in the development of the calyx of Held as one of the best preparations in which to study synaptic transmission. Here we review some of these advances, including simultaneous recording of pre- and postsynaptic currents, measuring the Ca2+ sensitivity of transmitter release, reconstructing the 3-D anatomy at the electron microscope (EM) level, and modelling the buffered diffusion of Ca2+ in the nerve terminal. An important outcome of these studies is an improved understanding of the Ca2+ signal that controls phasic transmitter release. This article illustrates the spatial and temporal aspects of the three main steps in the presynaptic signalling cascade: Ca2+ influx through voltage-gated calcium channels, buffered Ca2+ diffusion from the channels to releasable vesicles, and activation of the Ca2+ sensor for release. Particular emphasis is placed on how presynaptic Ca2+ buffers affect the Ca2+ signal and thus the amplitude and time course of the release probability. Since many aspects of the signalling cascade were first conceived with reference to the squid giant presynaptic terminal, we include comparisons with the squid model and revisit some of its implications. Whilst the characteristics of buffered Ca2+ diffusion presented here are based on the calyx of Held, we demonstrate the circumstances under which they may be valid for other nerve terminals at mammalian CNS synapses. PMID:12562955

Meinrenken, Christoph J; Borst, J Gerard G; Sakmann, Bert

2003-01-01

146

SUPER-RESOLUTION FROM SHORT-TIME FOURIER TRANSFORM MEASUREMENTS Celine Aubel, David Stotz, and Helmut Bolcskei  

E-print Network

SUPER-RESOLUTION FROM SHORT-TIME FOURIER TRANSFORM MEASUREMENTS C´eline Aubel, David Stotz often has access to windowed Fourier transform measurements, i.e., short-time Fourier transform (STFT-factor penalty. Contributions: In practical applications one often has ac- cess to windowed Fourier transform, i

Bölcskei, Helmut

147

Short and long time behavior of the Fokker-Planck equation in a confining potential and applications  

E-print Network

Short and long time behavior of the Fokker-Planck equation in a confining potential Introduction and results In this article, we consider the linear Fokker-Planck equation in R2d x,v for d 3 the following result about the (short and) long time behavior of the solution of the Fokker- Planck equation: 2

Hérau, Frédéric

148

Brain tumour classification using short echo time 1 H MRS. Objective comparison of classification techniques (LDA, LS-SVM).  

E-print Network

Brain tumour classification using short echo time 1 H MRS. Objective comparison of classification techniques, for binary and multiclass classification of short echo time 1 H spectra. The influence of several for binary and multiclass classification was measured respectively by Receiver Operating Characteristic (ROC

149

Ordering and short-time orientational diffusion in dipolar hard-spherical colloids.  

PubMed

Orientational hydrodynamic functions and short-time, self-orientational and collective orientational diffusion coefficients of dipolar hard-spherical colloids are performed on a homogeneous isotropic phase, as functions of the wave vector q, for various values of the volume fraction and the dipolar strength of the macroparticles. The calculation is based on the dynamic orientational structure factor, which is the time-dependent self-correlation of the orientation density. We assume that the time evolution of the orientation density is given by the Smoluchoswki's equation, taking into account the hydrodynamic interactions as well as the dipolar interaction. The former are considered assuming pairwise additivity. The importance of the dynamic orientational structure factor is that its initial slope can be measured in a depolarized light scattering experiment. The results predict a different behavior for dilute and for dense dipolar colloids. The ordering phenomena are studied via the ordering coefficients, which are the orientational hydrodynamic functions at q=0. The results show that as the dipolar colloid evolves to the instability line, the translational ordering velocity increases while the rotational one reduces. The short-time orientational diffusion coefficients at q=0 are also performed. They predict that near to the instability line, the dipolar colloid diffuses translationally more than rotationally. At very dilute concentration the dipolar colloid presents an unexpected dynamical behavior, which seems to indicate that the colloid could be evolving to a reentrant phase. PMID:11909052

Alarcón-Waess, O; Diaz-Herrera, E

2002-03-01

150

Short time spreading and wetting of offset printing liquids on model calcium carbonate coating structures.  

PubMed

Spreading of oils and water on porous and pre-saturated model carbonate coating structures was studied with high speed video imaging. The short-time data were complemented with long time absorption and wicking experiments. The results indicate a strong dependence between surface structural features of the pigment tablets and water spreading at short times, both in non-saturated and water pre-saturated cases, while the oil spreading is mainly dependent on the liquid properties. Sodium polyacrylate dispersant on pigment surfaces is shown to contribute to water spreading and absorption. On pre-saturated structures the liquid-liquid interactions are dominant and the majority of results support spreading according to the molecular kinetic model. The evidence supports the hypothesis of S. Rousu, P. Gane, and D. Eklund, ["Influence of coating pigment chemistry and morphology on the chromatographic separation of offset ink constituents," in The Science of Papermaking Transactions of the 12th Fundamental Research Symposium, FRC The Pulp & Paper Fundamental Research Society, Oxford, UK, 2001, p. 1115] that at long times the oils absorb into the porous structure at a rate proportional to the ratio of viscosity and surface tension, provided there is no sorptive action with the binder. A combination of nanosized pores and large surface area is useful for providing sufficient absorption capability for carbonate based coatings. PMID:22196346

Koivula, Hanna; Toivakka, Martti; Gane, Patrick

2012-03-01

151

Time functions of deep earthquakes from broadband and short-period stacks  

USGS Publications Warehouse

To constrain dynamic source properties of deep earthquakes, we have systematically constructed broadband time functions of deep earthquakes by stacking and scaling teleseismic P waves from U.S. National Seismic Network, TERRAscope, and Berkeley Digital Seismic Network broadband stations. We examined 42 earthquakes with depths from 100 to 660 km that occurred between July 1, 1992 and July 31, 1995. To directly compare time functions, or to group them by size, depth, or region, it is essential to scale them to remove the effect of moment, which varies by more than 3 orders of magnitude for these events. For each event we also computed short-period stacks of P waves recorded by west coast regional arrays. The comparison of broadband with short-period stacks yields a considerable advantage, enabling more reliable measurement of event duration. A more accurate estimate of the duration better constrains the scaling procedure to remove the effect of moment, producing scaled time functions with both correct timing and amplitude. We find only subtle differences in the broadband time-function shape with moment, indicating successful scaling and minimal effects of attenuation at the periods considered here. The average shape of the envelopes of the short-period stacks is very similar to the average broadband time function. The main variations seen with depth are (1) a mild decrease in duration with increasing depth, (2) greater asymmetry in the time functions of intermediate events compared to deep ones, and (3) unexpected complexity and late moment release for events between 350 and 550 km, with seven of the eight events in that depth interval displaying markedly more complicated time functions with more moment release late in the rupture than most events above or below. The first two results are broadly consistent with our previous studies, while the third is reported here for the first time. The greater complexity between 350 and 550 km suggests greater heterogeneity in the failure process in that depth range. Copyright 1998 by the American Geophysical Union.

Houston, H.; Benz, H. M.; Vidale, J. E.

1998-01-01

152

An analytic algorithm for global coverage of the revisiting orbit and its application to the CFOSAT satellite  

NASA Astrophysics Data System (ADS)

This paper addresses a new analytic algorithm for global coverage of the revisiting orbit and its application to the mission revisiting the Earth within long periods of time, such as Chinese-French Oceanic Satellite (abbr., CFOSAT). In the first, it is presented that the traditional design methodology of the revisiting orbit for some imaging satellites only on the single (ascending or descending) pass, and the repeating orbit is employed to perform the global coverage within short periods of time. However, the selection of the repeating orbit is essentially to yield the suboptimum from the rare measure of rational numbers of passes per day, which will lose lots of available revisiting orbits. Thus, an innovative design scheme is proposed to check both rational and irrational passes per day to acquire the relationship between the coverage percentage and the altitude. To improve the traditional imaging only on the single pass, the proposed algorithm is mapping every pass into its ascending and descending nodes on the specified latitude circle, and then is accumulating the projected width on the circle by the field of view of the satellite. The ergodic geometry of coverage percentage produced from the algorithm is affecting the final scheme, such as the optimal one owning the largest percentage, and the balance one possessing the less gradient in its vicinity, and is guiding to heuristic design for the station-keeping control strategies. The application of CFOSAT validates the feasibility of the algorithm.

Xu, Ming; Huang, Li

2014-08-01

153

Short-time behavior of advecting-diffusing scalar fields in Stokes flows.  

PubMed

This article addresses the short-term decay of advecting-diffusing scalar fields in Stokes flows. The analysis is developed in two main subparts. In the first part, we present an analytic approach for a class of simple flow systems expressed mathematically by the one-dimensional advection-diffusion equation w(y)?(?)?=??(y)(2)?+iV(y)?-?'?, where ? is either time or axial coordinate and iV(y) an imaginary potential. This class of systems encompasses both open- and closed-flow models and corresponds to the dynamics of a single Fourier mode in parallel flows. We derive an analytic expression for the short-time (short-length) decay of ?, and show that this decay is characterized by a universal behavior that depends solely on the singularity of the ratio of the transverse-to-axial velocity components V(eff)(y)=V(y)/w(y), corresponding to the effective potential in the imaginary potential formulation. If V(eff)(y) is smooth, then ||?||(L(2))(?)=exp(-?'?-b?(3)), where b>0 is a constant. Conversely, if the effective potential is singular, then ||?||(L(2))(?)=1-a?(?) with a>0. The exponent ? attains the value 5/3 at the very early stages of the process, while for intermediate stages its value is 3/5. By summing over all of the Fourier modes, a stretched exponential decay is obtained in the presence of nonimpulsive initial conditions, while impulsive conditions give rise to an early-stage power-law behavior. In the second part, we consider generic, chaotic, and nonchaotic autonomous Stokes flows, providing a kinematic interpretation of the results found in the first part. The kinematic approach grounded on the warped-time transformation complements the analytical theory developed in the first part. PMID:23848776

Giona, M; Anderson, P D; Garofalo, F

2013-06-01

154

Short-time behavior of advecting-diffusing scalar fields in Stokes flows  

NASA Astrophysics Data System (ADS)

This article addresses the short-term decay of advecting-diffusing scalar fields in Stokes flows. The analysis is developed in two main subparts. In the first part, we present an analytic approach for a class of simple flow systems expressed mathematically by the one-dimensional advection-diffusion equation w(y)???=??y2?+iV(y)?-?'?, where ? is either time or axial coordinate and iV(y) an imaginary potential. This class of systems encompasses both open- and closed-flow models and corresponds to the dynamics of a single Fourier mode in parallel flows. We derive an analytic expression for the short-time (short-length) decay of ?, and show that this decay is characterized by a universal behavior that depends solely on the singularity of the ratio of the transverse-to-axial velocity components Veff(y)=V(y)/w(y), corresponding to the effective potential in the imaginary potential formulation. If Veff(y) is smooth, then ||?||L2(?)=exp(-?'?-b?3), where b>0 is a constant. Conversely, if the effective potential is singular, then ||?||L2(?)=1-a?? with a>0. The exponent ? attains the value (5)/(3) at the very early stages of the process, while for intermediate stages its value is (3)/(5). By summing over all of the Fourier modes, a stretched exponential decay is obtained in the presence of nonimpulsive initial conditions, while impulsive conditions give rise to an early-stage power-law behavior. In the second part, we consider generic, chaotic, and nonchaotic autonomous Stokes flows, providing a kinematic interpretation of the results found in the first part. The kinematic approach grounded on the warped-time transformation complements the analytical theory developed in the first part.

Giona, M.; Anderson, P. D.; Garofalo, F.

2013-06-01

155

Phase-field theory of brine entrapment in sea ice: Short-time frozen microstructures  

E-print Network

We analyze the early phase of brine entrapment in sea ice, using a phase field model. This model for a first-order phase transition couples non-conserved order parameter kinetics to salt diffusion. The evolution equations are derived from a Landau-Ginzburg order parameter gradient dynamics together with salinity conservation. The numerical solution of model equations by an exponential time differencing scheme describes the time evolution of phase separation between liquid water with high salinity and the ice phase with low salinity. The numerical solution in one and two dimensions indicates the formation of one dominant wavelength which sets the length scale of short-time frozen structures. A stability analysis provides the phase diagram in terms of two Landau parameters. It is distinguished an uniform ice phase, a homogeneous liquid saline water solution and a phase where solidification structures can be formed. The Landau parameters are extracted from the supercooling and superheating as well as the freezin...

Thoms, Silke; Morawetz, Klaus

2014-01-01

156

Thick-target bremsstrahlung interpretation of short time-scale solar hard X-ray features  

NASA Technical Reports Server (NTRS)

Steady-state analyses of bremsstrahlung hard X-ray production in solar flares are appropriate only if the lifetime of the high energy electrons in the X-ray source is much shorter than the duration of the observed X-ray burst. For a thick-target nonthermal model, this implies that a full time-dependent analysis is required when the duration of the burst is comparable to the collisional lifetime of the injected electrons, in turn set by the lengths and densities of the flaring region. In this paper we present the results of such a time-dependent analysis, and we point out that the intrinsic temporal signature of the thick-target production mechanism, caused by the finite travel time of the electrons through the target, may indeed rule out such a mechanism for extremely short duration hard X-ray events.

Emslie, A. G.

1983-01-01

157

Ship motion extreme short time prediction of ship pitch based on diagonal recurrent neural network  

NASA Astrophysics Data System (ADS)

A DRNN (diagonal recurrent neural network) and its RPE (recurrent prediction error) learning algorithm are proposed in this paper. Using of the simple structure of DRNN can reduce the capacity of calculation. The principle of RPE learning algorithm is to adjust weights along the direction of Gauss-Newton. Meanwhile, it is unnecessary to calculate the second local derivative and the inverse matrixes, whose unbiasedness is proved. With application to the extremely short time prediction of large ship pitch, satisfactory results are obtained. Prediction effect of this algorithm is compared with that of auto-regression and periodical diagram method, and comparison results show that the proposed algorithm is feasible.

Shen, Yan; Xie, Mei-Ping

2005-06-01

158

Extraction of self-diffusivity in systems with nondiffusive short-time behavior  

NASA Astrophysics Data System (ADS)

We consider a toy model that captures the short-time nondiffusive behavior seen in many physical systems, to study the extraction of self-diffusivity from particle trajectories. We propose and evaluate a simple method to automatically detect the transition to diffusive behavior. We simulate the toy model to generate data sets of varying quality and test different methods of extracting the self-diffusion coefficient and characterizing its uncertainty. We find that weighted least-squares with statistical bootstrap is the most accurate and efficient means for analyzing the trajectory data. The analysis suggests an iterative recipe for designing simulations to conform to a specified level of accuracy.

Shanbhag, Sachin

2013-10-01

159

Time of flight emission spectroscopy of laser produced nickel plasma: Short-pulse and ultrafast excitations  

NASA Astrophysics Data System (ADS)

We report the experimental investigation and comparison of the temporal features of short-pulse (7 ns) and ultrafast (100 fs) laser produced plasmas generated from a solid nickel target, expanding into a nitrogen background. When the ambient pressure is varied in a large range of 10-6 Torr to 102 Torr, the plume intensity is found to increase rapidly as the pressure crosses 1 Torr. Time of flight (TOF) spectroscopy of emission from neutral nickel (Ni I) at 361.9 nm (3d9(2D) 4p ? 3d9(2D) 4s transition) reveals two peaks (fast and slow species) in short-pulse excitation and a single peak in ultrafast excitation. The fast and slow peaks represent recombined neutrals and un-ionized neutrals, respectively. TOF emission from singly ionized nickel (Ni II) studied using the 428.5 nm (3p63d8(3P) 4s? 3p63d9 4s) transition shows only a single peak for either excitation. Velocities of the neutral and ionic species are determined from TOF measurements carried out at different positions (i.e., at distances of 2 mm and 4 mm, respectively, from the target surface) on the plume axis. Measured velocities indicate acceleration of neutrals and ions, which is caused by the Coulomb pull of the electrons enveloping the plume front in the case of ultrafast excitation. Both Coulomb pull and laser-plasma interaction contribute to the acceleration in the case of short-pulse excitation. These investigations provide new information on the pressure dependent temporal behavior of nickel plasmas produced by short-pulse and ultrafast laser pulses, which have potential uses in applications such as pulsed laser deposition and laser-induced nanoparticle generation.

Smijesh, N.; Chandrasekharan, K.; Joshi, Jagdish C.; Philip, Reji

2014-07-01

160

Seasonal Short-Lived Radium Activity in the Venice Lagoon: The Role of Residence Time  

NASA Astrophysics Data System (ADS)

Radium is considered to be an excellent tracer of submarine groundwater discharge (SGD) and, therefore, has been used in many studies of this process in the past decade. Comprehensive surveys of excess 223,224Ra activity were completed in the surface waters of the Venice Lagoon over 6 seasons in order to quantify seasonal variation of SGD into the lagoon. The mass balance of radium found that SGD was 5-26 times greater than total river discharge (35.5 m3 s-1), and that total SGD could differ by almost an order of magnitude pending season. Several possible parameters, which may cause the seasonal variation, were tested. These included precipitation events, average tidal elevation, average tidal excursion, wind speed and direction, yet none provided a satisfactory explanation for the difference. Residence time based on a hydrodynamic model, however, was very strongly correlated with the observed variation. When the average residence time in the lagoon was low (5 days) the SGD was calculated to be 930 m3 s-1 and when the average residence time was high (9 days) the SGD was quantified as 160 m3 s-1. Radioactive decay is already accounted for in the mass balance model and therefore this correlation must be explained by another process. The Venice Lagoon is characterized by low residence time during periods of spring tides and bora or northerly winds, both of which create exceptionally strong currents in the Venice Lagoon. The currents as well as the large tidal excursion which occurs at spring tides drive a recirculation of seawater through the surface sediments, which greatly increases short-lived Ra activity in the surface waters. This evidence suggests, therefore, that short-lived Ra mass balance studies, which are based on a single survey, may under or overestimate the mean annual SGD pending the hydrodynamics of the investigated location.

Rapaglia, J.; Ferrarin, C.; Zaggia, L.; Umgiesser, G.; Zuppi, G.; Manfe', G.

2008-12-01

161

Alterations of Visual Reaction Time and Short Term Memory in Military Radar Personnel  

PubMed Central

Background Radar transmitters emit high-power radiofrequency radiation by creation of a high-voltage and high-frequency alternating electrical current. Methods: Health effects of occupational exposure to military radar were investigated. Visual reaction time was recorded with a simple blind computer-assisted-visual reaction time test. To assess the short-term memory, modified Wechsler Memory Scale test was performed. Results: The mean +/- SD reaction time in radar works (N=100) and the control group (N=57) were 238.58 +/? 23.47 milliseconds and 291.86 +/? 28.26 milliseconds (P<0.0001), respectively. The scores of forward digit span in radar works and the control group were 3.56 +/? 0.77 and 4.29 +/? 1.06 (P<0.0001), while the scores of backward digit span in radar works and the control group were 2.70 +/? 0.69 and 3.62 +/? 0.95 (P<0.0001). The scores of word recognition in radar works and the control group were 3.37 +/? 1.13 and 5.86 +/? 1.11 (P<0.0001). Finally, the scores of paired words in radar works and the control group were 13.56 +/? 1.78 and 15.21 +/? 2.20 (P<0.0001). It can be concluded that occupational exposures to radar radiations decreases reaction time, which may lead to a better response to different hazards. Conclusion: To the best of our knowledge, this is the first study to show that occupational exposure to radar microwave radiation leads to decreased reaction time and the lower performance of short-term memory. Altogether, these results indicate that occupational exposure to radar microwave radiations may be linked to some non-detrimental and detrimental health effects. PMID:23785684

MORTAZAVI, Seyed Mohammad Javad; TAEB, Shahram; DEHGHAN, Naser

2013-01-01

162

Protein supplementation during a short-interval prostaglandin-based protocol for timed AI in sheep.  

PubMed

The aim of this experiment was to improve the reproductive performance of a short-interval prostaglandin (PG)-based protocol for timed artificial insemination in sheep, using a short-term nutritional treatment. During the breeding season (March-April), 132 multiparous and 61 nulliparous Corriedale ewes grazing natural pastures (600kg DM/ha, 8.5% CP), were allocated to two groups: 1, Control group (n=100) two injections of D-Cloprostenol (75?g per dose, 7d apart: Synchrovine(®) protocol); and 2, Supplemented group (n=93) ewes in which stage of the oestrous cycle was synchronised with Synchrovine(®) protocol plus focus feeding of a protein supplement (33.8% CP) between PG doses (Day -7 to -2). Cervical AI was performed at fixed time (Day 0), 46±1.0h after the second PG injection using 150 million sperm per ewe. Ovulation rate (Day 10), pregnancy rate, prolificacy and fecundity at Day 69 were evaluated by ultrasonography. Ovulation rate at Day 10 (1.20±0.05 vs. 1.22±0.05), pregnancy (46±0.05 vs. 56±0.05), prolificacy (1.09±0.04 vs. 1.06±0.05), and fecundity (0.49±0.06 vs. 0.59±0.06) at Day 69, were similar between groups (P>0.05; Control and Supplemented group respectively). It is concluded that focus feeding for 6d with protein supplementation during a short-interval PG-based protocol (Synchrovine(®)) did not improve the reproductive outcome associated with this protocol. PMID:25129637

Fierro, S; Gil, J; Viñoles, C; Soca, F; Banchero, G; Olivera-Muzante, J

2014-10-01

163

Acceleration of proliferative response of mouse fibroblasts by short-time pretreatment with polyphenols.  

PubMed

Under the hypothesis that photo-irradiated proanthocyanidin could accelerate wound healing through reactive oxygen species (ROS) formation, we examined the effect of proanthocyanidin on 3T3-L1 mouse fibroblasts with or without photo-irradiation. As a result, irrespective of presence or absence of photo-irradiation, only 1 min exposure of the cells to proanthocyanidin resulted in accelerated proliferation of the cells in a concentration-dependent manner. Similarly to proanthocyanidin, 1 min pretreatment with catechin, caffeic acid, and chlorogenic acid accelerated the proliferative response, but gallic acid, epicatechin gallate, epigallocatechin, and epigallocatechin gallate failed. If incorporated active ingredient such as proanthocyanidin for such a short time as 1 min accelerates the proliferation response, a bioassay was conducted by utilizing antioxidant potential of proanthocyanidin. That is, intracellular oxidation of 2',7'-dichlorodihydrofluorescin induced by H2O2 was significantly inhibited when the cells were pretreated with proanthocyanidin for 1 min, suggesting that incorporated proanthocyanidin into the cells exerted antioxidant effect. This was also supported by a liquid chromatography/mass spectrometry analysis in which incorporation of proanthocyanidin components such as catechin monomers and dimers into the cells within 1 min was confirmed. These results suggest that active polyphenolic compounds such as proanthocyanidin, catechin, caffeic acid, and chlorogenic acid incorporated into the cells in such a short time as 1 min could accelerate the proliferative response of the cells. PMID:25173673

Tsuruya, Makoto; Niwano, Yoshimi; Nakamura, Keisuke; Kanno, Taro; Nakashima, Takuji; Egusa, Hiroshi; Sasaki, Keiichi

2014-11-01

164

Long and short time quantum dynamics: I. Between Green's functions and transport equations  

NASA Astrophysics Data System (ADS)

This paper summarizes the present views on construction of the electron quantum transport equations based on the Non-Equilibrium Green's Functions approach. The basic tool is the so-called Ansatz decoupling; one Ansatz family stems from the original Kadanoff-Baym Ansatz and is suitable for extending the quasi-particle picture of the Landau theory out of equilibrium. The other family based on the Generalized KB Ansatz is appropriate for short time transients. The physical and formal context of the Ansatzes is analyzed; the most important question explored is the status of the Reconstruction Theorems, reducing a full description of a non-equilibrium system to a dynamic theory in terms of one-particle quantities. A comparison is made between the Time Dependent Density Functional Theory and the properly renormalized NGF formalism. There is a close relationship between both formalisms. The Reconstruction Theorems form a general basis for obtaining improved quantum transport equations.

Špi?ka, Václav; Velický, Bed?ich; Kalvová, And?la

2005-10-01

165

Distribution of interspike intervals estimated from multiple spike trains observed in a short time window.  

PubMed

Several nonparametric estimators of the probability distribution of interspike intervals are introduced. The methods are suitable for simultaneous spike trains observed in a time window of length comparable with the mean interspike interval. This reflects the situation in which a high number of input spike trains converge to a single cortical neuron that has to react in a relatively short time. The simulation study is performed to compare the estimators. For that purpose, several types of stationary point processes are considered as the models of neuronal activity. The methods permit one to estimate the distribution of interspike intervals even if practically none of them are observed. The Kaplan-Meier estimator seems to be the most flexible and reliable among all studied methods, but no direct conclusions as to how real neurons work can be deduced from it. PMID:21405716

Pawlas, Zbyn?k; Lansky, Petr

2011-01-01

166

Distribution of interspike intervals estimated from multiple spike trains observed in a short time window  

NASA Astrophysics Data System (ADS)

Several nonparametric estimators of the probability distribution of interspike intervals are introduced. The methods are suitable for simultaneous spike trains observed in a time window of length comparable with the mean interspike interval. This reflects the situation in which a high number of input spike trains converge to a single cortical neuron that has to react in a relatively short time. The simulation study is performed to compare the estimators. For that purpose, several types of stationary point processes are considered as the models of neuronal activity. The methods permit one to estimate the distribution of interspike intervals even if practically none of them are observed. The Kaplan-Meier estimator seems to be the most flexible and reliable among all studied methods, but no direct conclusions as to how real neurons work can be deduced from it.

Pawlas, Zbyn?k; Lansky, Petr

2011-01-01

167

Characterization of nitrifying microbial community in a submerged membrane bioreactor at short solids retention times.  

PubMed

This study investigated the nitrifying bacterial community in membrane bioreactor (MBR) at short solids retention times (SRTs) of 3, 5 and 10 days. The denaturing gradient gel electrophoresis results showed that different types of ammonia-oxidizing bacteria (AOB) can survive at different operating conditions. The diversity of AOB increased as the SRT increased. The real-time PCR results showed that the amoA gene concentrations were similar when MBRs were stabilized, and it can be a good indicator of stabilized nitrification. The results of clone library indicated that Nitrosomonas was the dominant group of AOB in three reactors. The microarray results showed that Nitrospira was the dominant group of nitrite-oxidizing bacteria (NOB) in the system. All groups of AOB and NOB except Nitrosolobus and Nitrococcus were found in MBR, indicated that the nitrifying bacterial community structure was more complicated. The combination of some molecular tools can provide more information of microbial communities. PMID:24099975

Duan, Liang; Song, Yonghui; Xia, Siqing; Hermanowicz, Slawomir W

2013-12-01

168

EXPLORING THE POTENTIAL OF SHORT-TIME FOURIER TRANSFORMS FOR ANALYZING SKIN CONDUCTANCE AND PUPILLOMETRY IN REAL-TIME APPLICATIONS  

SciTech Connect

The development of real-time predictors of mental workload is critical for the practical application of augmented cognition to human-machine systems. This paper explores a novel method based on a short-time Fourier transform (STFT) for analyzing galvanic skin conductance (SC) and pupillometry time-series data to extract estimates of mental workload with temporal bandwidth high-enough to be useful for augmented cognition applications. We tested the method in the context of a process control task based on the DURESS simulation developed by Vincente and Pawlak (1994; ported to Java by Cosentino,& Ross, 1999). SC, pupil dilation, blink rate, and visual scanning patterns were measured for four participants actively engaged in controlling the simulation. Fault events were introduced that required participants to diagnose errors and make control adjustments to keep the simulator operating within a target range. We were interested in whether the STFT of these measures would produce visible effects of the increase in mental workload and stress associated with these events. Graphical exploratory data analysis of the STFT showed visible increases in the power spectrum across a range of frequencies directly following fault events. We believe this approach shows potential as a relatively unobtrusive, low-cost, high bandwidth measure of mental workload that could be particularly useful for the application of augmented cognition to human-machine systems.

Roger Lew; Brian P. Dyre; Steffen Werner; Jeffrey C. Joe; Brian Wotring; Tuan Tran

2008-09-01

169

Night-time evaporation from a short-rotation willow stand  

NASA Astrophysics Data System (ADS)

The aim of the present study was to quantify and analyse the evaporation during night-time in a willow ( Salix viminalis L.) short-rotation stand. Evaporation measurements were made throughout the 24 h period on 76 days during the 1988 growing season using the energy-balance/Bowen-ratio method. Canopy conductance was estimated using a rearranged form of the Penman combination equation. The mean hourly evaporation rate during daytime was 0.18 mm h -1 and the corresponding value during night-time was 0.013 mm h -1, about 7% of the daytime rate. The mean cumulative night-time evaporation was 0.12 mm per night or 4.3% of the mean daytime evaporation. The highest night-time evaporation occurred in September and October with 0.21 mm and 0.36 mm per night, respectively, some 30-35% of the daytime evaporation during these periods. Total night-time evaporation for the growing season was estimated as 21 mm. Night-time evaporation was controlled mainly by vapour pressure deficit and ventilation whereas net radiation had only a minor influence. The night-time canopy resistance was estimated for a shorter period when the canopy was completely closed (leaf area index around 5) and the soil evaporation could be assumed negligible. The canopy resistance ranged between 10 and 220 s m -1 depending on vapour pressure deficit. The dependence on vapour pressure deficit during night-time was similar to the dependence during daytime but with a much larger sensitivity during the dark period.

Iritz, Zinaida; Lindroth, Anders

1994-05-01

170

Short time-step performances of coaxial and double U-tube borehole heat exchangers: Modeling and measurements  

Microsoft Academic Search

Several authors have investigated the long time-step performance of borehole heat exchangers. In that time scale, the borehole thermal capacitance is generally neglected, since the time span of interest is on the order of months or years. The borehole thermal capacitance consists both of grouting material and heat carrier fluid, and it mostly affects the short time-step behavior, when hourly

Angelo Zarrella; Massimiliano Scarpa; Michele De Carli

2011-01-01

171

A covariantly foliated higher dimensional space-time: Implications for short distance gravity and BSM physics  

E-print Network

We consider the space-time at short distances in which it is described by a $D$-dimensional manifold (bulk) carrying out the principal bundle structure. As a result, this space-time manifold is foliated in the covariant way by the $(D-4)$-dimensional submanifolds, realized as the space-like internal spaces, that are smooth copies of the Lie group $G$ considered in this paper as the special unitary group. The submanifolds being transversal to the internal spaces are realized as the external spaces and in fact identified as the usual $4$-dimensional world. The fundamental degrees of freedom determining the geometrical dynamics of the bulk corresponding with short distance gravity are given by the gauge fields, the external metric field and the modulus fields setting dynamically the volume of the internal spaces. These gauge fields laying the bulk is to point precisely out the local directions of the external spaces which depend on the topological non-triviality of the space-time principal bundle. The physical size of the internal spaces is fixed dynamically by the moduli stabilization potential which completely arise from the intrinsic geometry of the bulk. A detail description of the low energy bulk gravity in the weak field limit is given around the classical ground state of the bulk. Additionally, we investigate the dynamics of the fundamentally $4$-dimensional Weyl spinor fields and the fields of carrying out the non-trivial representations of the Lie group $G$ propagating in the bulk in a detail study. These results suggest naturally the possible solutions to some the experimental problems of Standard Model, the smallness of the observed neutrino masses and a dark matter candidate.

Cao H. Nam

2014-07-31

172

Using the short-time speech transmission index to predict speech reception thresholds in fluctuating noise.  

PubMed

The Speech Transmission Index (STI) predicts the intelligibility of speech degraded by noise and reverberation. Recently, Payton and Shrestha [J. Acoust. Soc. Am. 134, 3818-3827 (2013)] reported on the ability of a short-time speech-based STI (ssSTI) to predict the intelligibility of speech in the presence of fluctuating noise using analysis windows shorter than 1 s. They found the ssSTI highly correlated with theoretical STI calculations using windows as short as 0.3 s. In the current work, extended versions of the ssSTI were investigated for their ability to improve speech intelligibility prediction in the presence of fluctuating noise; a condition for which the long-term STI incorrectly predicts the same intelligibility as for stationary noise. No STI metric predicts a normal-hearing listener's improved ability to perceive speech in the presence of fluctuating noise as compared to stationary noise at the same signal-to-noise ratio. The investigated technique used window lengths that varied with octave band, based on human auditory temporal resolution as in the Extended Speech Intelligibility Index [Rhebergen and Versfeld, J. Acoust. Soc. Am. 117, 2181-2192 (2005)]. An extended sSTI using speech-shaped noise instead of speech as a probe predicted published speech reception thresholds for a variety of conditions. PMID:25235329

Ferreira, Matthew; Payton, Karen

2014-04-01

173

The incidence of short time scale variability on different types of Blazars  

NASA Astrophysics Data System (ADS)

Active Galactic Nuclei (AGNs) have an extreme behavior at almost all wavelengths. In particular, the kind of AGNs know as blazars are one of the most extreme. With their jets pointing near to our direction, those object show a variety of distinctive features from radio to very high energies. We present the results of an extended campaign to study the behavior of the optical emission of blazars. This work is centered on variability at short scales of total flux. We took special care in data treatment, e.g. considering the influence of the host galaxies, the good choice of the field stars used for differential photometry, the statistical test used to study the variability, etc. Over the last years, we followed blazars that were detected at very high energies (TeV). We found differences in the incidence of variability at short time-scales between blazars that have the peak of their synchrotron flux low frequencies from those that have it at high energies.

Andruchow, I.; Cellone, S. A.; Romero, G. E.

2014-10-01

174

Modeling of on-line catalyst addition effects in a short contact time reactor  

SciTech Connect

Recently developed short-contact-time reactors (SCTR), consisting of porous alumina monoliths coated with platinum, have been shown to produce ethylene from rich ethane/oxygen(hydrogen) mixtures with yields and selectivities comparable to conventional steam cracking, using a reactor of much smaller size. Although the overall mechanism is clearly autothermal and catalytic, the details, in particular the relative contributions of heterogeneous and homogeneous chemistry, are a matter of considerable debate. Recent experiments show that reactor performance can be further enhanced by dripping a dilute platinum solution onto the SCTR front face during reaction, resulting in catalyst deposition within only a short (several millimeter) zone of the reactor. The authors have undertaken a computational study of this system, using two-dimensional computational fluid dynamics simulations with full heat and mass transport and detailed heterogeneous and homogeneous kinetic mechanisms. The results indicate that front-face catalyst loading enhances reactor performance by limiting the opportunity for heterogeneous ethane reactions that produce methane. As a result, ethylene selectivity increases and CH{sub 4} selectivity decreases. The results strongly support a mechanism recently proposed by the authors, in which rapid, heterogeneous oxidation of adsorbed hydrogen consumes most of the oxygen. The resulting heat is then released to the gas phase, causing homogeneous pyrolysis of ethane to occur in an environment containing much less oxygen. This mechanism explains not only the effects of on-line catalyst addition, but also the increase in ethylene selectivity observed upon addition of hydrogen to the reactant mixture.

D. K. Zerkle; M. d. Allendorf; M. Wolf; O. Deutschmann

2000-07-30

175

Qualitative Features Extraction from Sensor Data using Short-time Fourier Transform  

NASA Technical Reports Server (NTRS)

The information gathered from sensors is used to determine the health of a sensor. Once a normal mode of operation is established any deviation from the normal behavior indicates a change. This change may be due to a malfunction of the sensor(s) or the system (or process). The step-up and step-down features, as well as sensor disturbances are assumed to be exponential. An RC network is used to model the main process, which is defined by a step-up (charging), drift, and step-down (discharging). The sensor disturbances and spike are added while the system is in drift. The system runs for a period of at least three time-constants of the main process every time a process feature occurs (e.g. step change). The Short-Time Fourier Transform of the Signal is taken using the Hamming window. Three window widths are used. The DC value is removed from the windowed data prior to taking the FFT. The resulting three dimensional spectral plots provide good time frequency resolution. The results indicate distinct shapes corresponding to each process.

Amini, Abolfazl M.; Figueroa, Fernando

2004-01-01

176

Fluctuation of similarity to detect transitions between distinct dynamical regimes in short time series  

NASA Astrophysics Data System (ADS)

A method to identify distinct dynamical regimes and transitions between those regimes in a short univariate time series was recently introduced [N. Malik et al., Europhys. Lett. 97, 40009 (2012), 10.1209/0295-5075/97/40009], employing the computation of fluctuations in a measure of nonlinear similarity based on local recurrence properties. In this work, we describe the details of the analytical relationships between this newly introduced measure and the well-known concepts of attractor dimensions and Lyapunov exponents. We show that the new measure has linear dependence on the effective dimension of the attractor and it measures the variations in the sum of the Lyapunov spectrum. To illustrate the practical usefulness of the method, we identify various types of dynamical transitions in different nonlinear models. We present testbed examples for the new method's robustness against noise and missing values in the time series. We also use this method to analyze time series of social dynamics, specifically an analysis of the US crime record time series from 1975 to 1993. Using this method, we find that dynamical complexity in robberies was influenced by the unemployment rate until the late 1980s. We have also observed a dynamical transition in homicide and robbery rates in the late 1980s and early 1990s, leading to increase in the dynamical complexity of these rates.

Malik, Nishant; Marwan, Norbert; Zou, Yong; Mucha, Peter J.; Kurths, Jürgen

2014-06-01

177

Catalytic incineration of VOC containing air streams at very short contact times  

SciTech Connect

A short-contact-time catalytic combustor described here is capable of incinerating air streams with low concentrations of volatile organic compounds (VOCs) at conversions exceeding 99.5% for contact times on the order of 5 ms. This is accomplished by adding methane to the VOC-containing air stream to increase the fuel stream value and then passing the mixture over a platinum-coated foam ceramic monolith at 900--1,400 C. The incineration of air streams containing toluene, chlorobenzene, acetonitrile, and thiophene was examined at concentrations ranging from 500 to 2,000 PPM. Residence time and methane concentration do not affect strongly the outlet concentration of the VOC and conversion. Greater than 99.5% conversion is observed for all compounds examined for residence times ranging from 4 to 12 ms and methane concentrations from 5.5 to 7.0% (80--40% excess air). The mechanism of reaction in this system is primarily heterogeneous, with some homogeneous reactions driven by the heat liberated by the heterogeneous reactions. A simple homogeneous model shows that homogeneous chemistry alone cannot account for complete conversion of the additional methane fuel at the reaction conditions described.

Goralski, C.T. Jr.; Schmidt, L.D. [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science] [Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science; Brown, W.L. [Rust Environment and Infrastructure, Minneapolis, MN (United States)] [Rust Environment and Infrastructure, Minneapolis, MN (United States)

1998-08-01

178

Influence of Ramadan Fasting on Anaerobic Performance and Recovery Following Short time High Intensity Exercise  

PubMed Central

The aim of this study was to investigate the effects of Ramadan fasting on anaerobic power and capacity and the removal rate of lactate after short time high intensity exercise in power athletes. Ten male elite power athletes (2 wrestlers, 7 sprinters and 1 thrower, aged 20-24 yr, mean age 22.30 ± 1.25 yr) participated in this study. The subjects were tested three times [3 days before the beginning of Ramadan (Pre-RF), the last 3 days of Ramadan (End-RF) and the last 3 days of the 4th week after the end of Ramadan (After-RF)]. Anaerobic power and capacity were measured by using the Wingate Anaerobic Test (WAnT) at Pre-RF, End-RF and After- RF. Capillary blood samples for lactate analyses and heart rate recordings were taken at rest, immediately after WAnT and throughout the recovery period. Repeated measures of ANOVA indicated that there were no significant changes in body weight, body mass index, fat free mass, percentage of body fat, daily sleeping time and daily caloric intake associated with Ramadan fasting. No significant changes were found in total body water either, but urinary density measured at End-RF was significantly higher than After-RF. Similarity among peak HR and peak LA values at Pre-RF, End- RF and After-RF demonstrated that cardiovascular and metabolic stress caused by WAnT was not affected by Ramadan fasting. In addition, no influence of Ramadan fasting on anaerobic power and capacity and removal rate of LA from blood following high intensity exercise was observed. The results of this study revealed that if strength-power training is performed regularly and daily food intake, body fluid balance and daily sleeping time are maintained as before Ramadan, Ramadan fasting will not have adverse effects on body composition, anaerobic power and capacity, and LA metabolism during and after high intensity exercise in power athletes. Key pointsNo significant changes were assessed on body composition, daily sleeping time and caloric intake, and body fluid balance in regularly trained power athletes during Ramadan fasting.Ramadan fasting has no adverse effect on power outputs of short time high intensity exercise.No influence of Ramadan fasting on LA metabolism during high intensity exercise and passive recovery in regularly trained power athletes. PMID:24149483

Karli, Umid; Guvenc, Alpay; Aslan, Alper; Hazir, Tahir; Acikada, Caner

2007-01-01

179

Phase transitions in ceramic oxides as the result of processes with short time high temperature action  

SciTech Connect

Different materials belonging to two groups based on Al{sub 2}O{sub 3} and ZrO{sub 2} have been studied. These materials are applied as components of high temperature resistant protective coatings particularly in thermal barrier coating deposited by plasma spraying process and studied on thermal shock resistance with the use of a special arrangement. Both processes are characterised by short time high temperature action and subsequent high cooling rate which causes phase transitions in the studied materials. In the first group of materials based on Al{sub 2}O{sub 3} two forms of {beta}-Al{sub 2}TiO{sub 5} obtained by annealing in furnace and plasma spraying have been compared. In the second group of materials based on ZrO{sub 2} special attention is directed to materials stabilized by rare earth oxides and phase transitions occuring in the dependence on composition and processing.

Gorski, L. [Institute of Atomic Energy, Swierk-Otwock (Poland)

1995-09-01

180

Methanosarcina domination in anaerobic sequencing batch reactor at short hydraulic retention time.  

PubMed

The Archaea population of anaerobic sequential batch reactor (ASBR) featuring cycle operations under varying hydraulic retention time (HRT) was evaluated for treating a dilute waste stream. Terminal-Restriction Length Polymorphism and clone libraries for both 16S rRNA gene and mcrA gene were employed to characterize the methanogenic community structure. Results revealed that a Methanosarcina dominated methanogenic community was successfully established when using an ASBR digester at short HRT. It was revealed that both 16S rRNA and mcrA clone library could not provide complete community structure, while combination of two different clone libraries could capture more archaea diversity. Thermodynamic calculations confirmed a preference for the observed population structure. The results both experimentally and theoretically confirmed that Methanosarcina dominance emphasizing ASBR's important role in treating low strength wastewater as Methanosarcina will be more adept at overcoming temperature and shock loadings experienced with treating this type of wastewater. PMID:23584407

Ma, Jingwei; Zhao, Baisuo; Frear, Craig; Zhao, Quanbao; Yu, Liang; Li, Xiujin; Chen, Shulin

2013-06-01

181

Phase-field theory of brine entrapment in sea ice: Short-time frozen microstructures  

E-print Network

We analyze the early phase of brine entrapment in sea ice, using a phase field model. This model for a first-order phase transition couples non-conserved order parameter kinetics to salt diffusion. The evolution equations are derived from a Landau-Ginzburg order parameter gradient dynamics together with salinity conservation. The numerical solution of model equations by an exponential time differencing scheme describes the time evolution of phase separation between liquid water with high salinity and the ice phase with low salinity. The numerical solution in one and two dimensions indicates the formation of one dominant wavelength which sets the length scale of short-time frozen structures. A stability analysis provides the phase diagram in terms of two Landau parameters. It is distinguished an uniform ice phase, a homogeneous liquid saline water solution and a phase where solidification structures can be formed. The Landau parameters are extracted from the supercooling and superheating as well as the freezing point temperature of water. With the help of realistic parameters the distribution of brine inclusions is calculated and found in agreement with the measured samples. The size of the ice domains separating regions of concentrated seawater depends on salinity and temperature and corresponds to the size of sea ice platelets obtained from a morphological stability analysis for the solidification of salt water.

Silke Thoms; Bernd Kutschan; Klaus Morawetz

2014-05-01

182

Complexity signatures for short time scales in the atmosphere above Adventdalen, Svalbard  

NASA Astrophysics Data System (ADS)

parameters from the troposphere above Adventdalen, Svalbard, 78°N, 16°E, are examined for signatures of complexity in their respective stochastic components over time scales from ~1 h to 1 year. Several approaches are used, all of which can estimate values of the generalized Hurst exponent, ?, which can in turn be compared with each other and with similar independent characterizations, usually via the classic Hurst exponent, H, obtained from location-specific and globally averaged time series. For tropopause altitude, the stochastic component exhibits the signature of a persistent fractional Gaussian noise (fGn) with ? ? 0.75. For surface air temperature, the indications are for fractional Brownian motion (fBm) with ? ? 1.4. Using recent high time-resolution data from a single high-latitude location, this identification of fBm is relevant for short-term memory as opposed to findings from many other studies addressing possible long-term memory, which demonstrate fGn with ? = H ? 0.7. Furthermore, the lack of similarity between the results for surface air temperature and tropopause altitude suggests that different underlying processes are responsible for stochastic variability.

Hall, C. M.

2014-01-01

183

Short Dissipation Times of Proto-planetary Disks: An Artifact of Selection Effects?  

NASA Astrophysics Data System (ADS)

The frequency of disks around young stars, a key parameter for understanding planet formation, is most readily determined in young stellar clusters where many relatively coeval stars are located in close proximity. Observational studies seem to show that the disk frequency decreases rapidly with cluster age with <10% of cluster stars retaining their disks for longer than 2-6 Myr. Given that at least half of all stars in the field seem to harbor one or more planets, this would imply extremely fast disk dispersal and rapid planet growth. Here we question the validity of this constraint by demonstrating that the short disk dissipation times inferred to date might have been heavily underestimated by selection effects. Critically, for ages >3 Myr only stars that originally populated the densest areas of very populous clusters, which are prone to disk erosion, are actually considered. This tiny sample may not be representative of the majority of stars. In fact, the higher disk fractions in co-moving groups indicate that it is likely that over 30% of all field stars retain their disks well beyond 10 Myr, leaving ample time for planet growth. Equally, our solar system, with a likely formation time >10 Myr, need no longer be an exception but in fact typical of planetary systems.

Pfalzner, Susanne; Steinhausen, Manuel; Menten, Karl

2014-10-01

184

Real-time monitoring and short-term forecasting of drought in Norway  

NASA Astrophysics Data System (ADS)

Drought is considered to be one of the most costly natural disasters. Drought monitoring and forecasting are thus important for sound water management. In this study hydrological drought characteristics applicable for real-time monitoring and short-term forecasting of drought in Norway were developed. A spatially distributed hydrological model (HBV) implemented in a Web-based GIS framework provides a platform for drought analyses and visualizations. A number of national drought maps can be produced, which is a simple and effective way to communicate drought conditions to decision makers and the public. The HBV model is driven by precipitation and air temperature data. On a daily time step it calculates the water balance for 1 x 1 km2 grid cells characterized by their elevation and land use. Drought duration and areal drought coverage for runoff and subsurface storage (sum of soil moisture and groundwater) were derived. The threshold level method was used to specify drought conditions on a grid cell basis. The daily 10th percentile thresholds were derived from seven-day windows centered on that calendar day from the reference period 1981-2010 (threshold not exceeded 10% of the time). Each individual grid cell was examined to determine if it was below its respective threshold level. Daily drought-stricken areas can then be easily identified when visualized on a map. The drought duration can also be tracked and calculated by a retrospective analysis. Real-time observations from synoptic stations interpolated to a regular grid of 1 km resolution constituted the forcing data for the current situation. 9-day meteorological forecasts were used as input to the HBV model to obtain short-term hydrological drought forecasts. Downscaled precipitation and temperature fields from two different atmospheric models were applied. The first two days of the forecast period adopted the forecasts from Unified Model (UM4) while the following seven days were based on the 9-day forecasts from ECMWF. The approach has been tested and is now available on the Web for operational water management.

Kwok Wong, Wai; Hisdal, Hege

2013-04-01

185

42 CFR 488.30 - Revisit user fee for revisit surveys.  

Code of Federal Regulations, 2010 CFR

... false Revisit user fee for revisit surveys. 488.30 Section 488.30 Public...CONTINUED) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES...488.30 Revisit user fee for revisit surveys. (a) Definitions. As used...

2010-10-01

186

42 CFR 488.30 - Revisit user fee for revisit surveys.  

Code of Federal Regulations, 2011 CFR

... false Revisit user fee for revisit surveys. 488.30 Section 488.30 Public...CONTINUED) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES...488.30 Revisit user fee for revisit surveys. (a) Definitions. As used...

2011-10-01

187

Storm time, short-lived bursts of relativistic electron precipitation detected by subionospheric radio wave propagation  

NASA Astrophysics Data System (ADS)

In this study we report on ground-based observations of short bursts of relativistic electron precipitation (REP), detected by a subionospheric propagation sensor in Sodankylä, Finland during 2005. In two ˜4 hour case study periods from L = 5.2, around local midnight, several hundred short-lived radio wave perturbations were observed, covering a wide range of arrival azimuths. The vast majority (˜99%) of these perturbations were not simultaneous with perturbations on other paths, consistent with a precipitation "rainstorm" producing ionospheric changes of small spatial sizes around the Sodankylä receiver. The recovery time of these radio wave perturbations are ˜1.2 s, which is consistent with the modeled effects of a burst of >2 MeV precipitating electrons. This agrees with satellite observations of the microburst energy spectrum. The energetic nature of the precipitation which produces the FAST perturbations suggests that they should be observable in both day and night conditions. While it is widely assumed that satellite-detected REP microbursts are due to wave-particle interactions with very low-frequency chorus waves, the energy spectra predicted by our current models of chorus propagation and wave-particle interaction are not consistent with the experimentally observed radio wave perturbations presented here or previously reported satellite observations of REP microbursts. The results inferred from both the satellite and subionospheric observations, namely the absence of a large, dominant component of <100 keV precipitating electrons, fundamentally disagrees with a mechanism of chorus-driven precipitation. Nonetheless, further work on the modeling of chorus-driven precipitation is required.

Rodger, Craig J.; Clilverd, Mark A.; Nunn, David; Verronen, Pekka T.; Bortnik, Jacob; Turunen, Esa

2007-07-01

188

Time-resolved observations of the short period CV SDSS J123813.73-033933.0  

E-print Network

We observed a new and poorly studied cataclysmic variable (CV) SDSS J123813.73-033933.0 to determine its classification and binary parameters. Simultaneous time-resolved photometric and spectroscopic observations were carried out to conduct period analysis and Doppler tomography mapping. From radial velocity measurements of the Ha line we determined its orbital period to be 0.05592+/-0.00035$ days (80.53min). This period is longer than the first estimate of 76 min by Szkody et al. (2003), but still at the very edge of the period limit for hydrogen-rich CVs. The spectrum shows double-peaked Balmer emission lines flanked by strong broad Balmer absorption, indicating a dominant contribution by the white dwarf primary star, and is similar to the spectra of short-period low-mass transfer WZ Sge-like systems. The photometric light curve shows complex variability. The system undergoes cyclic brightening up to 0.4 mags, which are of semi-periodic nature with periods of the order of 8-12 hours. We also detect a 40.25 min variability of ~0.15 mag corresponding to half of the orbital period. Amplitude of the latter increases with the cyclic brightening of the system. We discuss the variable accretion rate and its impact on the hot spot as the most probable reason for both observed processes. SDSS J123813.73-033933.0 is preliminary classified as a WZ Sge-like short period system with low and unstable accretion rate.

S. V. Zharikov; G. H. Tovmassian; R. Napiwotzki; R. Michel; V. Neustroev

2005-12-06

189

Time-evolution scenarios for short-range depletion gels subjected to the gravitational stress.  

PubMed

By exploiting photon correlation imaging and ghost particle velocimetry, two novel optical correlation techniques particularly suited to the investigation of the microscopic dynamics of spatially heterogeneous samples, we investigate the settling and restructuring dynamics of colloidal gels generated by short-ranged depletion interactions. Three distinct regions can be clearly set apart within the liquid-liquid coexistence region of the phase diagram where gel formation is observed. When depletion forces are barely sufficient to drive the system within the metastable region, an initial disordered gel hosts the rapid nucleation of crystallites, which stress the gel structure until it fully collapses, leading to the formation of a macroscopic colloidal crystal. For stronger attractive forces, two distinct scenarios are observed, depending on the particle volume fraction ?0 of the original suspension. At low ?0, the gel breaks after a short delay time into separate clusters, which rapidly settle until they compact in a denser disordered phase. The latter eventually undergoes a slow compression, which is accounted for by a poroelastic model where the microscopic gel dynamics is fully ruled by its macroscopic deformation. Yet, it is the intermediate stage between cluster settling and final compaction which displays very peculiar features, evidenced by anomalous settling profiles which are not shared, to our knowledge, by any other sedimentation processes investigated so far. For larger values of ?0, gel breaking is conversely suppressed, the structure undergoes a continuous compression that cannot be explained by a poroelastic model, and the microscopic dynamics is characterized by logarithmic correlation functions resembling those found for attractive glasses. PMID:24913393

Secchi, Eleonora; Buzzaccaro, Stefano; Piazza, Roberto

2014-08-01

190

Time-resolved fMRI of mental rotation revisited--dissociating visual perception from mental rotation in female subjects.  

PubMed

Functional neuroimaging studies have demonstrated that mental rotation paradigms activate a network of spatially distributed cortical areas rather than a discrete brain region. Although the neuro-anatomical nodes of the rotation network are well established, their specific functional role is less well identified. It was the aim of the present study to dissociate network components involved in the visual perception of 3D cubic objects from regions involved in their mental spatial transformation. This was achieved by desynchronizing the time course of the perceptional process (i.e., stimulus duration) from the duration of the cognitive process (i.e., reaction times) and by comparing these with the temporal characteristics of the hemodynamic response functions (HRFs) in regions of interest. To minimize intersubject variability, an all-female subject group was chosen for this investigation. Time-resolved fMRI analysis revealed a significant increase in the full width at half maximum (FWHM) of the HRF with reaction times in the supplementary motor area (pre-SMA), in the bilateral premotor cortex (PMd-proper), and in the left parietal lobe (PP). The FWHM in visual system components such as the bilateral lateral occipital complex (LOC) and dorsal extrastriate visual areas (DE) was constant across trials and roughly equal to the stimulus duration. These findings suggest that visual system activation during mental rotation reflects visual perception and can be dissociated from other network components whose response characteristics indicates an involvement in the mental spatial transformation itself. PMID:16650777

Ecker, Christine; Brammer, Michael J; David, Anthony S; Williams, Steven C

2006-08-01

191

Critical behavior of an Ising system on the Sierpinski carpet: A short-time dynamics study  

NASA Astrophysics Data System (ADS)

The short-time dynamic evolution of an Ising model embedded in an infinitely ramified fractal structure with noninteger Hausdorff dimension was studied using Monte Carlo simulations. Completely ordered and disordered spin configurations were used as initial states for the dynamic simulations. In both cases, the evolution of the physical observables follows a power-law behavior. Based on this fact, the complete set of critical exponents characteristic of a second-order phase transition was evaluated. Also, the dynamic exponent ? of the critical initial increase in magnetization, as well as the critical temperature, were computed. The exponent ? exhibits a weak dependence on the initial (small) magnetization. On the other hand, the dynamic exponent z shows a systematic decrease when the segmentation step is increased, i.e., when the system size becomes larger. Our results suggest that the effective noninteger dimension for the second-order phase transition is noticeably smaller than the Hausdorff dimension. Even when the behavior of the magnetization (in the case of the ordered initial state) and the autocorrelation (in the case of the disordered initial state) with time are very well fitted by power laws, the precision of our simulations allows us to detect the presence of a soft oscillation of the same type in both magnitudes that we attribute to the topological details of the generating cell at any scale.

Bab, M. A.; Fabricius, G.; Albano, E. V.

2005-03-01

192

Rapid growth, early maturation and short generation time in African annual fishes  

PubMed Central

Background Extreme environmental conditions can give rise to extreme adaptations. We document growth, sexual maturation and fecundity in two species of African annual fish inhabiting temporary savanna pools. Results Nothobranchius kadleci started to reproduce at the age of 17 days and size of 31 mm and Nothobranchius furzeri at 18 days and 32 mm. All four study populations demonstrated rapid growth rates of up to 2.72 mm/day (23.4% of their total length). Both species may produce diapausing embryos or embryos that are able to hatch in as few as 15 days, resulting in a minimum generation time as short as only one month. Incubation on the surface of damp peat moss results in high embryo survival (73%) and a high proportion of rapidly developing embryos (58%) that skip diapauses and hatch in less than 30 days. We further demonstrated that rapid growth and maturation do not compromise subsequent fecundity. Conclusions Our data suggest that both species have the most rapid sexual maturation and minimum generation time of any vertebrate species, and that rapid maturity does not involve paedogenesis. PMID:24007640

2013-01-01

193

Short-time diffusion in concentrated bidisperse hard-sphere suspensions  

E-print Network

Diffusion in bidisperse Brownian hard-sphere suspensions is studied by Stokesian Dynamics (SD) computer simulations and a semi-analytical theoretical scheme for colloidal short-time dynamics, based on Beenakker and Mazur's method [Physica 120A, 388 (1983) & 126A, 349 (1984)]. Two species of hard spheres are suspended in an overdamped viscous solvent that mediates the salient hydrodynamic interactions among all particles. In a comprehensive parameter scan that covers various packing fractions and suspension compositions, we employ numerically accurate SD simulations to compute the initial diffusive relaxation of density modulations at the Brownian time scale, quantified by the partial hydrodynamic functions. A revised version of Beenakker and Mazur's $\\delta\\gamma$-scheme for monodisperse suspensions is found to exhibit surprisingly good accuracy, when simple rescaling laws are invoked in its application to mixtures. The so-modified $\\delta\\gamma$ scheme predicts hydrodynamic functions in very good agreement with our SD simulation results, for all densities from the very dilute limit up to packing fractions as high as $40\\%$.

Mu Wang; Marco Heinen; John F. Brady

2014-10-31

194

Network Nation Revisited  

NSDL National Science Digital Library

The Network Nation Revisited" is an analysis of the predictions made by Hiltz and Turoff in _The Network Nation_, one of the seminal texts (published in 1978) in the field of Computer Mediated Communications.

195

"Sony Revisited," Revisited Another look at the paper that presaged  

E-print Network

that Sony took the staple-article doctrine of patent law as a model for its copyright safe-harbor rule"Sony Revisited," Revisited Another look at the paper that presaged Grokster and inducement of this paper is available at http://digital-law-online.info/papers/lah/sony-revisited.htm August 10, 2005 Draft

Hollaar, Lee A.

196

Revisiting the Regenerative Possibilities of Ortiz  

ERIC Educational Resources Information Center

The author of this article revisits Simon Ortiz's poem, "From Sand Creek," in which the latter can in so few words convey both the horrific tragedy of conquest and colonization, while at the same time find a space for possibility, a means for recovery that is never about forgetting but always occurs as a kind of recuperative remembering. Ortiz…

Duques, Matthew

2004-01-01

197

IN THIS ISSUE Light Signaling Revisited  

E-print Network

IN THIS ISSUE Light Signaling Revisited Plants respond to light in a myriad of ways. Between light- genesis and the control of flowering time. More than 50 years ago, Harry Borthwick and colleagues the pigment responsible for this effect, which they named phyto- chrome, and also described its role in seed

Schäfer, Eberhard

198

Broadcast Flooding Revisited: Survivability and Latency  

E-print Network

Broadcast Flooding Revisited: Survivability and Latency Petteri Mannersalo VTT Technical Research University Email: riedi@rice.edu Abstract--This paper addresses the dynamics of broadcast flooding in random wireless ad hoc networks. In particular, we study the subset of nodes covered by a flood as well as timing

Riedi, Rudolf H.

199

The Short-Time Compensation Program in France: An Efficient Measure  

E-print Network

" device in France, the Italian "Cassa Integrazione Guadagni", the German "Kurzarbeitergeld", the "Short by the temporary interruption of activity. Although STC programs in North America are relatively new

Paris-Sud XI, Université de

200

Effects of short storage conditions and broiler breeder age on hatchability, hatching time, and chick weights.  

PubMed

An experiment was conducted to assess how hatching performance is affected by breeder age and egg holding environment during short-term storage. Response variables analyzed were egg weight loss up to 18 d of incubation, viability (hatchability of fertile eggs), embryonic mortality, hatching time, and weight of male and female chicks, at hatching and at the end of incubation. The trials involved a total of 2,250 hatching eggs from each of two commercial broiler breeder flocks of the same strain (Avian) but of different ages (32 to 34 and 48 to 50 wk). Eggs were stored for 0, 1, or 2 d in the egg storage room or in the setter room. The hatching times of the chicks were recorded at 4-h intervals during the period from 478 to 494 h postincubation, and at 514 h, when incubation was terminated and all chicks were removed from the hatcher. In eggs from younger hens, viability was not influenced by preincubation storage; in older hens, viability of eggs not submitted to storage was higher (P < 0.05) by 3 to 6 percentage points than that of stored eggs. Hatching times were not affected by age of the hen, whereas male chicks tended to hatch, on average, about 3 h later than females. Chick weights at hatching and at removal from the hatcher were similar for both sexes, but females experienced a higher (P < 0.05) weight loss in that interval. Eggs incubated on the day of lay tended to hatch, on average, later than stored eggs (especially when compared to eggs submitted to 1 d storage), and produced heavier chicks. PMID:9355138

Reis, L H; Gama, L T; Soares, M C

1997-11-01

201

Revisiting Mr. Tall and Mr. Short  

ERIC Educational Resources Information Center

Ratio, rate, and proportion are central ideas in the Common Core State Standards (CCSS) for middle-grades mathematics (CCSSI 2010). These ideas closely connect to themes in earlier grades (pattern building, multiplicative reasoning, rational number concepts) and are the foundation for understanding linear functions as well as many high school…

Riehl, Suzanne M.; Steinthorsdottir, Olof Bjorg

2014-01-01

202

Revisiting the impact of part-time work on adolescent adjustment: distinguishing between selection and socialization using propensity score matching.  

PubMed

The impact of part-time employment on adolescent functioning remains unclear because most studies fail to adequately control for differential selection into the workplace. The present study reanalyzes data from L. Steinberg, S. Fegley, and S. M. Dornbusch (1993) using multiple imputation, which minimizes bias in effect size estimation, and 2 types of propensity score matching, to account for selection effects. In this sample (N = 1,792; Grades 10-11, M = 16.26), youth who begin working more than 20 hr per week evince declines in school engagement and increases in substance use and delinquency compared with youth who remain unemployed. Conversely, working 20 hr or less a week has negligible effects, positive or negative, on academic, psychological, or behavioral outcomes. PMID:21291431

Monahan, Kathryn C; Lee, Joanna M; Steinberg, Laurence

2011-01-01

203

Linear and synchrosqueezed time-frequency representations revisited. Part I: Overview, standards of use, related issues and algorithms  

E-print Network

Time-frequency representations (TFRs) of signals, such as windowed Fourier transform (WFT), wavelet transform (WT) and their synchrosqueezed variants (SWFT, SWT), provide powerful analysis tools. However, there are many important issues related to the practical use of TFRs that need to be clarified. Here we present a thorough review of these TFRs, summarizing all theoretical, practical and numerical aspects of their use, reconsidering some conventions and introducing new concepts and procedures. The purposes of this work are: (i) to provide a consistent overview of the computation, properties, and use of the (S)WFT/(S)WT methods; (ii) to establish general standards related to their use, both theoretical and practical; and (iii) to provide clean and optimized algorithms and MatLab codes, appropriate for any window or wavelet.

Iatsenko, Dmytro; Stefanovska, Aneta

2013-01-01

204

Differentiation Between Short and Long TCP Flows: Predictability of the Response Time  

E-print Network

mechanisms can lead to pathological behavior in extreme cases. Keywords. TCP/IP, M/G/1, Processor Sharing short and long flows in a TCP/IP network. There are several reasons to favor short flows. The reasons of a priori knowledge of the flow sizes, which obviously is not the case in the current TCP/IP architecture

Avrachenkov, Konstantin

205

L134N Revisited  

NASA Astrophysics Data System (ADS)

L134N (also known as L183) is a very cold, starless and nearby dark cloud which has attracted much attention from the astrochemists in the past. They have been using it as an oxygen-rich reference to test their models in parallel with TMC-1, the other, but carbon-rich, reference. However, our knowledge of the cloud temperature, structure, and various species abundances has relied for a long time largely on the work by Swade (1987a, 1987b) which suffers from low signal-to-noise C18O and CS maps and limited excitation analysis. This work has been recently repeated and improved by Dickens et al. (2000) but they still lack adequate surface coverage, higher rotational lines of important species and comparison with the dust. While FIRST will probably find many new species in this cloud, it is time to revisit completely this source in order to interpret correctly the FIRST results to come. We have thus made a complete survey of several transitions of CO, 13CO, C18O, C17O, CS, C34S, SO and 34SO species with the NRAO 12-m and CSO 10-m together with maps of the dust from ISO and SCUBA to assess the fundamental properties of this cloud. Preliminary results are reported here.

Pagani, L.; Pardo-Carrion, J. R.; Stepnik, B.

2001-07-01

206

Cyp11A1 canola plants under short time heat stress conditions.  

PubMed

In order to investigate the high temperature tolerance of spring canola plants (Brassica napus L.) constitutively expressing cyp11A1 gene which encodes bovine cytochrome P450(scc) the growth features were analyzed under short time heat stress (42 degrees C) in growth chamber. Earlier it was documented that results of the heat tolerance test positively correlated with improvement of high temperature resistance in field trial. Higher relative water content (by 13%) and superoxide dismutase (SOD) activity, lower electrolyte leakage (up 1.4-fold) and smaller increase in chlorophyll a and carotenoid contents in cyp11A1 canola leaves in comparison with wild-type plants under stress allowed to conclude cyp11A1 plants are more tolerant to high temperature than the control ones. We suppose that SOD activity increase which revealed in our transgenic canola in normal condition plays the defining role in the biochemical alterations in plant metabolism for the thermotolerance improvement. SOD activity increment could be caused by heterologous cytochrome P450(scc) activity which resulted in the superoxide radical formation. Cyp11A1 canola plants might be resistant to the other stress conditions of different origin. PMID:25318172

Sakhno, L O; Slyvets, M S; Kuchuk, M V

2014-01-01

207

Zipf's Law in Short-Time Timbral Codings of Speech, Music, and Environmental Sound Signals  

PubMed Central

Timbre is a key perceptual feature that allows discrimination between different sounds. Timbral sensations are highly dependent on the temporal evolution of the power spectrum of an audio signal. In order to quantitatively characterize such sensations, the shape of the power spectrum has to be encoded in a way that preserves certain physical and perceptual properties. Therefore, it is common practice to encode short-time power spectra using psychoacoustical frequency scales. In this paper, we study and characterize the statistical properties of such encodings, here called timbral code-words. In particular, we report on rank-frequency distributions of timbral code-words extracted from 740 hours of audio coming from disparate sources such as speech, music, and environmental sounds. Analogously to text corpora, we find a heavy-tailed Zipfian distribution with exponent close to one. Importantly, this distribution is found independently of different encoding decisions and regardless of the audio source. Further analysis on the intrinsic characteristics of most and least frequent code-words reveals that the most frequent code-words tend to have a more homogeneous structure. We also find that speech and music databases have specific, distinctive code-words while, in the case of the environmental sounds, this database-specific code-words are not present. Finally, we find that a Yule-Simon process with memory provides a reasonable quantitative approximation for our data, suggesting the existence of a common simple generative mechanism for all considered sound sources. PMID:22479497

Haro, Martin; Serra, Joan; Herrera, Perfecto; Corral, Alvaro

2012-01-01

208

SHORT CONTACT TIME DIRECT COAL LIQUEFACTION USING A NOVEL BATCH REACTOR  

SciTech Connect

The overall goal of this research is to develop an understanding of the Direct Coal Liquefaction process at the molecular level. Many approaches have been used to study this process including kinetic studies, study of the liquefaction products, study of the effect of reaction variables, such as temperature, solvent type and composition, the changing nature and composition of the coal during liquefaction, and the distribution in the liquefaction products of the hydrogen consumed. While all these studies have contributed to our growing knowledge of the liquefaction process, an adequate understanding of direct liquefaction still eludes us. This is due to many reasons including: the complexity and variable nature of coal itself and the many different chemical reactions which are occurring simultaneously during direct coal liquefaction. We believe that a study of the liquefaction process at the very early stages will avoid the complexities of secondary reactions associated with free radical high temperature processes that are clearly involved in direct coal liquefaction. This prompted us to devise a reactor system which avoids long heat up and cool-down times associated with previous kinetic studies, and allows kinetic measurements even at as short as the first few seconds of the liquefaction reaction.

Michael T. Klein; William H. Calkins

1997-10-29

209

Histological and cytological examination of rat reproductive tissue after short-time intermittent radiofrequency exposure.  

PubMed

The unfavourable outcomes of mobile phone use on male fertility have still not been fully elaborated. To establish the potentially adverse effects of everyday exposure to radiofrequency radiation (RF) on humans, we performed a controlled animal study that aimed to investigate the influence of RF radiation on rat testis histology as well as the amount, mobility, and structure of epididymal free sperm cell population. Eighteen adult male rats were divided into two groups of nine. One group comprised sham-exposed control animals, while the other group endured total body irradiation for an hour daily during two weeks. A 915 MHz RF field, power density of 2.4 W m(-2) and strength of 30 V m(-1) was generated in a Gigahertz Transversal Electromagnetic chamber. The specific absorption rate (SAR) was 0.6 W kg(-1). Body mass and temperature were measured before and after each exposure treatment. Immediately after the last exposure, the animals were sacrificed and testes removed and prepared for histological analysis. The free sperm cells were collected from the cauda epididymis and their quantity, quality, and morphology were microscopically determined using a haemocytometer. No statistically significant alteration in any of the endpoints was observed. This study found no evidence of an unfavourable effect of the applied RF radiation on testicular function or structure. Based on these results, we can conclude that short-time intermittent exposure to RF radiation does not represent a significant risk factor for rat reproductive functions. PMID:24384757

Troši?, Ivan?ica; Matauši?-Pišl, Mirjana; Pavi?i?, Ivan; Marjanovi?, Ana Marija

2013-12-01

210

Numerical modelling of geothermal vertical heat exchangers for the short time analysis using the state model size reduction technique  

Microsoft Academic Search

According to the introduction of a dynamic operating mode in ground-coupled heat pump systems, a short time analysis within and around borehole heat exchangers is required in the modern geothermal system simulation. A numerical modelling could be a proper answer for this challenge. However, the numerical model is time consuming and necessitates a large memory particularly in such large systems.

Eui-Jong Kim; Jean-Jacques Roux; Gilles Rusaouen; Frédéric Kuznik

2010-01-01

211

Received 21 Dec 2012 | Accepted 9 May 2013 | Published 14 Jun 2013 Short-time movement of E. coli chromosomal  

E-print Network

ARTICLE Received 21 Dec 2012 | Accepted 9 May 2013 | Published 14 Jun 2013 Short-time movement of E. coli chromosomal loci depends on coordinate and subcellular localization Avelino Javer1,*, Zhicheng in Escherichia coli at different growth rates. At these timescales, we observe for the first time a dependence

Cicuta, Pietro

212

Short time-scale LV systolic dynamics: pressure vs. volume clamps and effect of activation.  

PubMed

We recently proposed a new model-based approach to quantifying short time-scale left ventricular (LV) systolic dynamics. In this study we examine the hypothesis that the quantitation of LV dynamics using the proposed approach is independent of external mechanical perturbations and the level of activation. Mechanical perturbation independence was assessed in seven isolated ferret hearts in which controlled changes in pressure (pressure clamp) or volume (volume clamp) were introduced at the time of peak isovolumetric pressure (protocol 1), and responses to these clamps were analyzed over the first 16 ms. The model described both pressure- and volume-clamps responses equally well. Model parameters were not different among various pressure clamps, and parameters estimated from volume clamps could accurately predict responses to pressure clamps [r2 range: 0.993-0.999; normalized root-mean-square error (NRMSE) range: 2.35-5.86%]. To examine activation independence, volume- (4 hearts) and pressure-clamp (4 hearts) responses were obtained and analyzed for baseline and postextrasystolic potentiated beats in a manner similar to protocol 1. The model parameter values estimated from the baseline state accurately predicted responses for the postextrasystolic potentiated state (r2 and NRMSE range for volume-clamp data: 0.989-0.998 and 3.35-6.88%, respectively; r2 and NRMSE range for pressure-clamp data: 0.992-0.996 and 4.26-5.23%, respectively). Thus the proposed approach can dissect the contributions of changes in activation from those due to changes in contractile unit properties on the function of the intact LV. PMID:8456995

Shroff, S G; Campbell, K B; Kirkpatrick, R D

1993-03-01

213

Comparison of a short-time speech-based intelligibility metric to the speech transmission index and intelligibility dataa  

PubMed Central

Several algorithms have been shown to generate a metric corresponding to the Speech Transmission Index (STI) using speech as a probe stimulus [e.g., Goldsworthy and Greenberg, J. Acoust. Soc. Am. 116, 3679–3689 (2004)]. The time-domain approaches work well on long speech segments and have the added potential to be used for short-time analysis. This study investigates the performance of the Envelope Regression (ER) time-domain STI method as a function of window length, in acoustically degraded environments with multiple talkers and speaking styles. The ER method is compared with a short-time Theoretical STI, derived from octave-band signal-to-noise ratios and reverberation times. For windows as short as 0.3?s, the ER method tracks short-time Theoretical STI changes in stationary speech-shaped noise, fluctuating restaurant babble and stationary noise plus reverberation. The metric is also compared to intelligibility scores on conversational speech and speech articulated clearly but at normal speaking rates (Clear/Norm) in stationary noise. Correlation between the metric and intelligibility scores is high and, consistent with the subject scores, the metrics are higher for Clear/Norm speech than for conversational speech and higher for the first word in a sentence than for the last word. PMID:24180791

Payton, Karen L.; Shrestha, Mona

2013-01-01

214

Short contact time direct coal liquefaction using a novel batch reactor. Quarterly report, May 15, 1995--September 15, 1995  

SciTech Connect

The objective of this research is to optimize the design and operation of the bench scale batch reactor for coal liquefaction at short contact times (0.01 to 10 minutes or longer). Additional objectives are to study the kinetics of direct coal liquefaction, particularly at short reaction times, and to investigate the role of the organic oxygen components of coal and their reaction pathways during liquefaction. This quarterly report covers the status of progress toward these objectives. 3 refs., 14 figs., 2 tabs.

Klein, M.T.; Calkins, W.H.; Huang, He

1995-10-05

215

A coordinated approach for real-time short term hydro scheduling  

SciTech Connect

The paper describes a coordinated approach to short-term hydro scheduling and dispatch that has been developed as a part of the Tasmanian Hydro Electric Commission`s (HEC) new Energy Management System (EMS), which is being delivered by Landis and Gyr Energy Management. Tasmania`s hydro generation system consists of 40 reservoirs in six river catchments. The daily water release for each plant is scheduled using the HEC`s mid-term operation policy. The Hydro Scheduling and Commitment (HSC) function schedules the hydro units on a half hourly basis so that the allocated water release maximizes the energy production. This maximization of energy production is achieved by maximizing the head and this ensures that operation is always as close as possible to maximum efficiency. Mixed Integer Linear Programming is used with a detailed model of the interconnected hydro system to determine the half-hourly operation schedule. The Hydro Economic Dispatch (HED) function is used to implement the schedules produced by HSC in the real-time operation. The HED also uses a detailed model of the hydro system with a Linear Programming algorithm to ensure that each unit operates as close as possible to its head-dependent theoretical maximum efficiency point while meeting the desired storage levels specified by the HSC solution. HSC and HED have been tested against a number of operational scenarios and when it is fully integrated within the new EMS it is expected to yield annual stored energy savings up to 0.5% through more efficient hydro-electric system operation. It is expected to also provide additional savings by fostering improvements to the mid-term operating plan.

Tufegdzic, N. [Hydro Electric Commission, Hobart (Australia)] [Hydro Electric Commission, Hobart (Australia); Frowd, R.J. [Landis and Gyr Energy Management, San Jose, CA (United States)] [Landis and Gyr Energy Management, San Jose, CA (United States); Stadlin, W.O. [Macro Corp., Horsham, PA (United States)] [Macro Corp., Horsham, PA (United States)

1996-11-01

216

CRISPR revisited: structure prediction of CRISPR repeats Sita Lange1  

E-print Network

CRISPR revisited: structure prediction of CRISPR repeats Sita Lange1 , Omer S. Alkhnbashi 1 Regularly Interspaced Short Palindromic Repeats (CRISPRs), illustrated to the right. The CRISPR transcripts sequences have been found to match foreign virus or plasmid DNA. A set of CRISPR-associated (Cas) proteins

Will, Sebastian

217

Myolysis Revisited  

PubMed Central

Numerous procedures have been developed in recent decades that claim to provide significant improvement in myoma status without hysterectomy. However, what is the cost in time and money of these procedures? This is a review of the current literature regarding these recent procedures to determine which, if any, is the best treatment for myomas. We conducted a search of PubMed using the terms “bipolar-, cryo-, radiofrequency, laparoscopic-, focused high-energy MRI-guided ultrasound, and MRI-guided laser myolysis” to identify reports of the various procedures. Based on these published reports, we describe the various types of myolysis performed in multiple patients in outpatient facilities including patient outcomes, complications, cost, and efficiency of the procedures. PMID:19275864

2008-01-01

218

Superdiffusion revisited  

E-print Network

The concept of diffusion in collisionless space plasmas like those near the magnetopause and in the geomagnetic tail is reexamined from a fundamental statistical point of view making use of the division of particle orbits into waiting orbits and break-out into ballistic motion lying at the bottom, for instance, of L\\'evy flights and the celebrated $\\kappa$-distribution. A stringent derivation yields an anomalous diffusion coefficient increasing with time, thus describing superdiffusion. Contrary to wide belief, superdiffusion, though faster than classical, is a weak process. Absolute values of the coefficient are small due to the largeness of the anomalous collision frequency in waiting statistics compared with the infinitesimally small binary collision frequency. We provide parallel and perpendicular diffusion coefficients, determine the exponents of temporal increase, determine the power and $\\kappa$ for two-dimensional diffusion by referring to published numerical particle-in-cell simulations, fix the rang...

Treumann, R A

2014-01-01

219

Polybenzene revisited.  

PubMed

Polybenzene was described by O'Keeffe et al., as an embedding of a 6.82 net in the infinite periodic minimal D-surface, with a single type of carbon atoms and was predicted to have a substantially lower energy per atom in comparison to C60, the reference structure in Nanoscience. They also described a 6.82 net embedded in the periodic minimal P-surface. We give here a rational structure construction for three benzene-based units (a third one described here for the first time in literature) and the corresponding networks. Their stability, relative to C60 but also to diamonds (the classical diamond D6 and the pentagon-based diamond D5), was calculated at the Hartree-Fock level of theory. The results confirmed the previous stability evaluation and support these structures for laboratory preparation. A Graph-theoretical description, in terms of Omega polynomial, of the three infinite networks is also presented. PMID:24061361

Szefler, Beata; Diudea, Mircea V

2012-12-01

220

Palatogram revisited  

PubMed Central

It is the responsibility of the dentist to fabricate a denture that is fully functional and perfectly esthetic. One prime oral function that has always been overlooked in this regard is speech. It has been thought that speech will follow mere replacement of teeth and that it is the patient's duty to fine tune this function with practice. Phonetics, esthetics, function and comfort form the foundation of a successful prosthodontic treatment. Accurate approximation of palatal contours of a maxillary complete denture to a patient's tongue can improve speech intelligibility, if other factors such as tooth position, occlusal plane and occlusal vertical dimension are satisfactory. Customizing palatal contours of a maxillary complete denture can be accomplished by using tissue-conditioning material, which provides sufficient working time for a patient to pronounce a series of sibilant sounds while recording dynamic impression of the tongue. This article describes a technique of obtaining palatogram and customizing palatal contours of a maxillary complete denture with autopolymerizing acrylic resin to improve the intelligibility of speech. PMID:24808716

Jain, Ashish R.; Venkat Prasad, M. K.; Ariga, Padma

2014-01-01

221

Palatogram revisited.  

PubMed

It is the responsibility of the dentist to fabricate a denture that is fully functional and perfectly esthetic. One prime oral function that has always been overlooked in this regard is speech. It has been thought that speech will follow mere replacement of teeth and that it is the patient's duty to fine tune this function with practice. Phonetics, esthetics, function and comfort form the foundation of a successful prosthodontic treatment. Accurate approximation of palatal contours of a maxillary complete denture to a patient's tongue can improve speech intelligibility, if other factors such as tooth position, occlusal plane and occlusal vertical dimension are satisfactory. Customizing palatal contours of a maxillary complete denture can be accomplished by using tissue-conditioning material, which provides sufficient working time for a patient to pronounce a series of sibilant sounds while recording dynamic impression of the tongue. This article describes a technique of obtaining palatogram and customizing palatal contours of a maxillary complete denture with autopolymerizing acrylic resin to improve the intelligibility of speech. PMID:24808716

Jain, Ashish R; Venkat Prasad, M K; Ariga, Padma

2014-01-01

222

Estimating return periods of extreme values from relatively short time series of winds  

NASA Astrophysics Data System (ADS)

An important factor for determining the prospect of individual wind farm sites is the frequency of extreme winds at hub height. Here, extreme winds are defined as the value of the highest 10 minutes averaged wind speed with a 50 year return period, i.e. annual exceeding probability of 2% (Rodrigo, 2010). A frequently applied method to estimate winds in the lowest few hundred meters above ground is to extrapolate observed 10-meter winds logarithmically to higher altitudes. Recent study by Drechsel et al. (2012) showed however that this methodology is not as accurate as interpolating simulated results from the global ECMWF numerical weather prediction (NWP) model to the desired height. Observations of persistent low level jets near Colima in SW-Mexico also show that the logarithmic approach can give highly inaccurate results for some regions (Arfeuille et al., 2012). To address these shortcomings of limited, and/or poorly representative, observations and extrapolations of winds one can use NWP models to dynamically scale down relatively coarse resolution atmospheric analysis. In the case of limited computing resources one has typically to make a compromise between spatial resolution and the duration of the simulated period, both of which can limit the quality of the wind farm siting. A common method to estimate maximum winds is to fit an extreme value distribution (e.g. Gumbel, gev or Pareto) to the maximum values of each year of available data, or the tail of these values. If data are only available for a short period, e.g. 10 or 15 years, then this will give a rather inaccurate estimate. It is possible to deal with this problem by utilizing monthly or weekly maxima, but this introduces new problems: seasonal variation, autocorrelation of neighboring values, and increased discrepancy between data and fitted distribution. We introduce a new method to estimate return periods of extreme values of winds at hub height from relatively short time series of winds, simulated at a high spatial resolution. REFERENCES Arfeuille, Gilles J. M., A. L. Quintanilla, L. Zizumbo, and F. C. Viesca, 2012. Wind Resource Assessment in a Tropical Region with Complex Terrain using SODAR and a Meteorological Tower Network to Measure Low Level Jets and Boundary Layer Conditions. 15th AMS Conference on Mountain Meteorology, Steam boat Spring, Colorado, USA, August 2012. Available on-line: https://ams.confex.com/ams/15MountMet/webprogram/Manuscript/Paper210184/ARFEUILLLE_etal_15MountMet Conf_Aug2012.pdf Drechsel S., G. J. Mayr, J. W. Messner, and R. Stauffer, 2012: Wind Speeds at Heights Crucial for Wind Energy: Measurements and Verification of Forecasts. J. Appl. Meteor. Climatol., 51, 1602-1617. Rodrigo, J. S., 2010. State-of-the-Art of Wind Resource Assessment. CENER National Renewable Energy Center, Sarriguren, Spain. Available on-line: http://www.waudit-itn.eu/download.php?id=103&parent=79

Jonasson, Kristjan; Agustsson, Halfdan; Rognvaldsson, Olafur; Arfeuille, Gilles

2013-04-01

223

Late-time X-ray Behavior of Short GRBs: Implications for Energetics and Rates  

NASA Astrophysics Data System (ADS)

The distribution of jet angles for short GRBs is critical to constrain because it has direct implications for the true energy scale and event rate, parameters of interest for gravitational wave detections. Our current knowledge of the opening angle distribution comes from X-ray observations >1 day after the burst. We propose XMM TOO observations to monitor a short GRB afterglow and constrain its collimation from the (non)detection of a jet break, to constrain or measure >5-20 deg. A precise calculation of the angle also requires broad-band afterglow observations; with our ongoing radio, optical/NIR short GRB TOO programs, our group is uniquely poised to provide the tightest constraints on these angles. We briefly discuss the published results from our AO-12 program.

Fong, Wen-Fai

2013-10-01

224

Improvement of capability for classifying odors in dynamically changing concentration using QCM sensor array and short-time Fourier transform  

Microsoft Academic Search

In this paper, we propose a method for improving the capability of odor classification in dynamical change of concentration often encountered in the ambient air. Quartz crystal microbalance (QCM) sensors are used to measure the sensor responses in this research. Our proposed method employs a short-time Fourier transform (STFT) algorithm and a stepwise discriminant analysis for feature extraction and dimensional

N. Nimsuk; T. Nakamoto

2007-01-01

225

hal-00004028,version3-23Jan2008 Short and long time behavior of the Fokker-Planck equation  

E-print Network

hal-00004028,version3-23Jan2008 Short and long time behavior of the Fokker-Planck equation consider the linear Fokker-Planck equation in a confining po- tential in space dimension d 3. Using applica- tions. R´esum´e: On consid`ere l'´equation de Fokker-Planck avec un potentiel confi- nant en

Paris-Sud XI, Université de

226

Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural transformations: Molecular dynamics study  

E-print Network

Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural transformations: Molecular dynamics study Zhibin Lin and Leonid V. Zhigilei* Department of Materials Science dynamics simulations of a 20 nm Au film irradiated with 200 fs laser pulses of different intensity

Zhigilei, Leonid V.

227

Short term effects of air pollution on health: a European approach using epidemiologic time series data: the APHEA protocol  

Microsoft Academic Search

BACKGROUND AND OBJECTIVES: Results from several studies over the past five years have shown that the current levels of pollutants in Europe and North America have adverse short term effects on health. The APHEA project aims to quantifying these in Europe, using standardised methodology. The project protocol and analytical methodology are presented here. DESIGN: Daily time series data were gathered

K Katsouyanni; J Schwartz; C Spix; G Touloumi; D Zmirou; A Zanobetti; B Wojtyniak; J M Vonk; A Tobias; A Pönkä; S Medina; L Bachárová; H R Anderson

1996-01-01

228

Investigating oceanic tidal energy dissipation on deep time scales using short tidal deposit sequences  

NASA Astrophysics Data System (ADS)

One of the enduring problems in physical oceanography has been that of tidal dynamics and the effective tidal torque that serves to slow Earth's axial rotation. In the late 20th century, with the aid of satellite altimetry and other technologies, a suite of reliable estimates was finally placed on the magnitude of this torque and other, related parameters in the current epoch. Tidal drag accounts for a 20 microsecond/year increase in mean day length, a 3.5 terawatt dissipation of energy in the oceans (Kantha et al., 1998), and a lunar retreat rate of 3.82 cm/yr (Dickey et al., 1994). Despite these significant advances, however, the problem of tidal dissipation in the geologic past remains largely unresolved. This is due, in part, to difficulties in numerical modeling of past tidal regimes that stem from uncertainties in ocean basin configurations and lunar distances. Tidal deposits can record, to high resolution, the primary astronomical periodicities responsible for the generation of the tidal currents under which transport and deposition occur. With reliable lunar orbital period data obtained from tidal deposits, the past Earth-Moon distance and length of day can be calculated. This task requires careful spectral analysis and consideration of sedimentological factors that may add noise and/or discontinuities to the signal. For deposits representing less than one year of deposition, the necessary assumptions are that Earth's moment of inertia has not changed significantly over the time interval of interest and that the solar component of tidal dissipation can be well-approximated. With consideration of the total angular momentum of the Earth-Moon couplet, we derive a method to calculate lunar distance and length of day. The efficacy of this method and its assumptions is tested via the multi-year sequence of data obtained from the late Precambrian Elatina Formation of Australia and comparing results obtained from the full suite of data by Williams (2000). We go on to analyze a short (3.5 month) Carboniferous dataset from the Abbott Formation of the Illinois Basin, USA. The results suggest non-linearity in ocean tidal dissipation since the late Precambrian and an average lunar retreat rate since the Carbiniferous below the present value, despite a larger lunar distance. With more tidal deposit data analyzed in this way, a much more complete picture of dissipation and Earth-Moon evolution could be realized.

Coughenour, C.

2012-12-01

229

Short-time asymptotics of a rigorous path integral for N = 1 supersymmetric quantum mechanics on a Riemannian manifold  

NASA Astrophysics Data System (ADS)

Following Feynman's prescription for constructing a path integral representation of the propagator of a quantum theory, a short-time approximation to the propagator for imaginary-time, N = 1 supersymmetric quantum mechanics on a compact, even-dimensional Riemannian manifold is constructed. The path integral is interpreted as the limit of products, determined by a partition of a finite time interval, of this approximate propagator. The limit under refinements of the partition is shown to converge uniformly to the heat kernel for the Laplace-de Rham operator on forms. A version of the steepest descent approximation to the path integral is obtained, and shown to give the expected short-time behavior of the supertrace of the heat kernel.

Fine, Dana S.; Sawin, Stephen

2014-06-01

230

Synthesis of Mo(Si,Al)2 alloy by reactive hot pressing at low temperatures for a short time  

Microsoft Academic Search

Mo(Si,Al)2 alloy was prepared by reactive hot pressing at low temperatures for a short time under 20MPa in a vacuum using MoSi2, Mo and Al as starting powders. At 1160 °C, 5 min of soaking time was enough to obtain a high density alloy. At 1060 °C, however, 10min was needed. The formation of Mo(Si,Al)2 was accompanied by the melting

Guo-Jun Zhang; Xue-Mei Yue; Tadahiko Watanabe

1999-01-01

231

Short-time focused ultrasound hyperthermia enhances liposomal doxorubicin delivery and antitumor efficacy for brain metastasis of breast cancer  

PubMed Central

The blood–brain/tumor barrier inhibits the uptake and accumulation of chemotherapeutic drugs. Hyperthermia can enhance the delivery of chemotherapeutic agent into tumors. In this study, we investigated the effects of short-time focused ultrasound (FUS) hyperthermia on the delivery and therapeutic efficacy of pegylated liposomal doxorubicin (PLD) for brain metastasis of breast cancer. Murine breast cancer 4T1-luc2 cells expressing firefly luciferase were injected into female BALB/c mice striatum tissues and used as a brain metastasis model. The mice were intravenously injected with PLD (5 mg/kg) with/without 10-minute transcranial FUS hyperthermia on day 6 after tumor implantation. The amounts of doxorubicin accumulated in the normal brain tissues and tumor tissues with/without FUS hyperthermia were measured using fluorometry. The tumor growth for the control, hyperthermia, PLD, and PLD + hyperthermia groups was measured using an IVIS spectrum system every other day from day 3 to day 11. Cell apoptosis and tumor characteristics were assessed using immunohistochemistry. Short-time FUS hyperthermia was able to significantly enhance the PLD delivery into brain tumors. The tumor growth was effectively inhibited by a single treatment of PLD + hyperthermia compared with both PLD alone and short-time FUS hyperthermia alone. Immunohistochemical examination further demonstrated the therapeutic efficacy of PLD plus short-time FUS hyperthermia for brain metastasis of breast cancer. The application of short-time FUS hyperthermia after nanodrug injection may be an effective approach to enhance nanodrug delivery and improve the treatment of metastatic cancers. PMID:25278753

Wu, Sheng-Kai; Chiang, Chi-Feng; Hsu, Yu-Hone; Lin, Tzu-Hung; Liou, Houng-Chi; Fu, Wen-Mei; Lin, Win-Li

2014-01-01

232

A Time Series Analysis of U.K. Lottery Sales: Long and Short Run Price Elasticities  

Microsoft Academic Search

This paper estimates the long- and short-run elasticities for Lotto. It is particularly concerned with the dynamic response to price variations since, for some goods, this has sometimes been used to infer the presence of addiction. The price elasticity is identified through variation in the expected value of a Lotto ticket induced by rollovers whose high frequency results in surprisingly

Lisa Farrell; Edgar Morgenroth; Ian Walker

1999-01-01

233

Short-time-scale (year) variations of petroleum fluids from the U.S. Gulf Coast  

Microsoft Academic Search

Evolving short-term (less than 5 yr) compositional changes in hydrocarbon charge from some Eugene Island Block 330 (EI-330) wells are demonstrated. Storage, analytical, and production artifacts are shown to be minimal. In some wells, compositions remain constant from 1985 to 1993, whereas in others in the same reservoir, significant changes are observed. In some cases, temporal variability is greater than

Jean K Whelan; Lorraine Eglinton; Mahlon C Kennicutt; Yaorong Qian

2001-01-01

234

Multiplexing of short real-time messages for road transport informatics systems  

Microsoft Academic Search

Avoiding traffic collapses requires intelligent and integrated traffic systems, all of which rely on communication systems. For future dedicated short range communication systems (SRC), a 1 GHz band between 63 and 64 GHz has been assigned, integrating all kinds of road transport and traffic telematics (RTTT) services. This system will support both communication between vehicles and infrastructure (via beacons) as

L. M. Garcia Suarez; Josef Kaltwasser; Jiirgen Kassubek

1994-01-01

235

Short-Term Memory for Time in Children and Adults: A Behavioral Study and a Model  

ERIC Educational Resources Information Center

This experiment investigated the effect of the short-term retention of duration on temporal discrimination in 5- and 8-year-olds, as well as in adults, by using an episodic temporal generalization task. In each age group, the participants' task was to compare two successive durations (a standard and a comparison duration) separated by a retention…

Droit-Volet, Sylvie; Wearden, John; Delgado-Yonger, Maria

2007-01-01

236

Time Perspective and Identity Formation: Short-Term Longitudinal Dynamics in College Students  

ERIC Educational Resources Information Center

Planning for the future and developing a personalized identity are conceived of as important developmental tasks that adolescents and emerging adults are confronted with on the pathway to adulthood. The present study set out to examine whether both tasks develop in tandem by using a short-term longitudinal dataset consisting of 371 college…

Luyckx, Koen; Lens, Willy; Smits, Ilse; Goossens, Luc

2010-01-01

237

The Well of Time. Eighteen Short Stories from Philippine Contemporary Literature.  

ERIC Educational Resources Information Center

A collection of eighteen short stories by Filipino writers is presented. The selections represent a variety of images of Filipino culture, both urban and rural, and life styles in northern and southern Philippines. The aim of the anthology is that the student will learn to empathize with experience rendered in language, appreciate the Filipino…

Laygo, Teresito M., Comp.

238

Short-term pollution forecasts based on linear and nonlinear methods of time series analysis  

NASA Astrophysics Data System (ADS)

Urban air pollution is a complex mixture of toxic components, which may induce acute and chronic responses from sensitive groups, such as children and people with previous heart and respiratory insufficiencies. However, air pollution, presents a highly chaotic and non-linear behavior. In this work we analyzed several pollutants time series recorded in the urban area of Lisbon (Portugal) for the 2002-2006 period. Linear and nonlinear methods were applied in order to assess NO2, PM10 and O3 main trends and fluctuations and finally, to produce daily forecasts of the referred pollutants. Here we evaluate the potential of linear and non-linear neural networks (NN) to produce short-term forecasts, and also the contribution of meteorological variables (daily mean temperature, radiation, wind speed and direction, boundary layer height, humidity) to pollutants dispersion. Additionally, we assess the role of large-scale circulation patterns, usually referred as Weather types (WT) (from the ERA40/ECMWF and ECMWF SLP database) towards the occurrence of critical pollution events identified previously. The presence and importance of trends and fluctuation is addressed by means of two modelling approaches: (1) raw data modelling; (2) residuals modelling (after the removal of the trends from the original data). The relative importance of two periodic components, the weekly and the monthly cycles, is addressed. For the three pollutants, the approach based on the removal of the weekly cycle presents the best results, comparatively to the removal of the monthly cycle or to the use of the raw data. The best predictors are chosen independently for each monitoring station and pollutant through an objective procedure (backward stepwise regression). The analysis reveals that the most significant variables in predicting NO2 concentration are several NO2 measures, wind direction and speed and global radiation, while for O3 correspond to several O3 measures, O3 precursors and WT classification. Finally, for PM10, several PM10 measures, NO2 and CO, maximum temperature, wind direction, humidity and BLH, i.e., pollutants related to road traffic emissions and meteorological variables related to atmospheric stability. Moreover, validation results showed that non-linear NN models, on average, perform as well or worse as linear models for NO2, O3 and PM10. The results attained with an independent sample reveal a very good correlation between the predicted and observed values which confirms that linear models generalize well for independent data. The applied methods permit producing, in a simple and cost efficient way, different results for each monitoring station, which allows a good spatial resolution for Lisbon's urban area. Consistent with the performance measures, high pollutants' peak values were reproduced in most cases by each model. The attained results raises good prospects for urban air quality characterization, allowing further developments in order to produce an integrated air quality surveillance system for the area of Lisbon.

Russo, A.; Trigo, R. M.

2012-04-01

239

Stability and change in subjective well-being over short time periods  

Microsoft Academic Search

Recent research has reported high stability for subjective well-being over periods as long as 9 years, concluding that well-being is essentially unaffected by environmental change. Other research has suggested well-being is responsive to change in life circumstances, and appropriate for use as an adaptational outcome variable. The present research examined the stability of well-being over short periods (3–6 months) using

Kerry Chamberlain; Sheryl Zika

1992-01-01

240

Management development revisited  

Microsoft Academic Search

Provides reflection on the special issue. Revisits the questions: What is management development? Why is management development worthy of our attention? What is to be learnt and when? What are the most effective techniques? This issue has identified four types of management development (MD). Administrative MD is gained through the experience of long service. Dependent MD is grooming for promotion

Jaap Paauwe; Roger Williams

2001-01-01

241

Concept Image Revisited  

ERIC Educational Resources Information Center

Concept image and concept definition is an important construct in mathematics education. Its use, however, has been limited to cognitive studies. This article revisits concept image in the context of research on undergraduate students' understanding of the derivative which regards the context of learning as paramount. The literature, mainly on…

Bingolbali, Erhan; Monaghan, John

2008-01-01

242

Google Scholar revisited  

Microsoft Academic Search

Purpose – The purpose of this paper is to revisit Google Scholar. Design\\/methodology\\/approach – This paper discusses the strengths and weaknesses of Google Scholar. Findings – The Google Books project has given a massive and valuable boost to the already rich and diverse content of Google Scholar. The downside of the growth is that significant gaps remain for top ranking

Péter Jacsó

2008-01-01

243

Colloquial Hebrew Imperatives Revisited  

ERIC Educational Resources Information Center

In revisiting Bolozky's [Bolozky, Shmuel, 1979. "On the new imperative in colloquial Hebrew." "Hebrew Annual Review" 3, 17-24] and Bat-El's [Bat-El, Outi, 2002. "True truncation in colloquial Hebrew imperatives." "Language" 78(4), 651-683] analyses of colloquial Hebrew imperatives, the article argues for restricting Imperative Truncation to the…

Bolozky, Shmuel

2009-01-01

244

Revisiting Teachers as Learners  

ERIC Educational Resources Information Center

This article revisits the concept of teachers as learners within the context of radical changes that have taken place within the education system in England over the past 25 years. The concept of "professional courage" is discussed and examined in relation to questions and issues raised by Paulo Freire in a series of letters to teachers (1997).…

Thomson, Liz

2008-01-01

245

The Linguistic Repertoire Revisited  

ERIC Educational Resources Information Center

This article argues for the relevance of poststructuralist approaches to the notion of a linguistic repertoire and introduces the notion of language portraits as a basis for empirical study of the way in which speakers conceive and represent their heteroglossic repertoires. The first part of the article revisits Gumperz's notion of a linguistic…

Busch, Brigitta

2012-01-01

246

Revisiting Bioaccumulation Criteria  

EPA Science Inventory

The objective of workgroup 5 was to revisit the B(ioaccumulation) criteria that are currently being used to identify POPs under the Stockholm Convention and PBTs under CEPA, TSCA, REACh and other programs. Despite the lack of a recognized definition for a B substance, we defined ...

247

Anodic Polarization Curves Revisited  

ERIC Educational Resources Information Center

An experiment published in this "Journal" has been revisited and it is found that the curve pattern of the anodic polarization curve for iron repeats itself successively when the potential scan is repeated. It is surprising that this observation has not been reported previously in the literature because it immediately brings into…

Liu, Yue; Drew, Michael G. B.; Liu, Ying; Liu, Lin

2013-01-01

248

Revisiting Curriculum Potential  

ERIC Educational Resources Information Center

This article analyzes the notion of curriculum potential by revisiting the ideas of Miriam Ben-Peretz and Joseph Schwab. Invoking the German "Didaktik" tradition and by way of a curriculum-making framework, the paper argues that interpreting curriculum materials for curriculum potential requires a careful analysis and unpacking of the meanings and…

Deng, Zongyi

2011-01-01

249

Application of a short-time version of the Equalization-Cancellation model to speech intelligibility experiments with speech maskers.  

PubMed

A short-time-processing version of the Equalization-Cancellation (EC) model of binaural processing is described and applied to speech intelligibility tasks in the presence of multiple maskers, including multiple speech maskers. This short-time EC model, called the STEC model, extends the model described by Wan et al. [J. Acoust. Soc. Am. 128, 3678-3690 (2010)] to allow the EC model's equalization parameters ? and ? to be adjusted as a function of time, resulting in improved masker cancellation when the dominant masker location varies in time. Using the Speech Intelligibility Index, the STEC model is applied to speech intelligibility with maskers that vary in number, type, and spatial arrangements. Most notably, when maskers are located on opposite sides of the target, this STEC model predicts improved thresholds when the maskers are modulated independently with speech-envelope modulators; this includes the most relevant case of independent speech maskers. The STEC model describes the spatial dependence of the speech reception threshold with speech maskers better than the steady-state model. Predictions are also improved for independently speech-modulated noise maskers but are poorer for reversed-speech maskers. In general, short-term processing is useful, but much remains to be done in the complex task of understanding speech in speech maskers. PMID:25096111

Wan, Rui; Durlach, Nathaniel I; Colburn, H Steven

2014-08-01

250

Real-Time Visual Feedback for Learning to Perform Short Rhythms with Variations in Timing and Loudness  

Microsoft Academic Search

According to learning theories and empirical observations, communication between teachers and students is a crucial factor in effective learning of musical expressions. One possibility for improving this communication could be the introduction of visual feedback (VFB) in the lesson. In the current study, a new type of real-time VFB is proposed, which represents changes in acoustical parameters (loudness and timing)

M. Sadakata; D. Hoppe; A. Brandmeyer; R. Timmers; P. W. M. Desain

2008-01-01

251

Real-Time Visual Feedback for Learning to Perform Short Rhythms with Expressive Variations in Timing and Loudness  

Microsoft Academic Search

According to learning theories and empirical observations, communication between teachers and students is a crucial factor in effective learning of musical expressions. One possibility for improving this communication could be the introduction of visual feedback (VFB) in the lesson. In the current study, a new type of real-time VFB is proposed, which represents changes in acoustical parameters (loudness and timing)

Makiko Sadakata; David Hoppe; Alex Brandmeyer; Renee Timmers; Peter Desain

2008-01-01

252

Short contact time direct coal liquefaction using a novel batch reactor. Quarterly progress report, January 1--May 15, 1995  

SciTech Connect

The objective of this research is to optimize the design and operation of the bench scale batch reactor for coal liquefaction at short contact times (0.01 to 10 minutes or longer). Additional objectives are to study the kinetics of direct coal liquefaction particularly at short reaction times, and to investigate the role of the organic oxygen components of coal and their reaction pathways during liquefaction. Experimental progress is reported for uncatalyzed liquefactions, catalyzed liquefactions, liquefaction in the presence of solvents other than tetralin, and kinetics of gas formation during coal liquefaction. Analytical methods were developed for the determination of the boiling range of coal liquids by thermogravimetric analysis and the determination of phenolic hydroxyl in coal, coal liquids, and coal residues.

Klein, M.T.; Calkins, W.H.

1995-05-31

253

Human brain detects short-time nonlinear predictability in the temporal fine structure of deterministic chaotic sounds  

NASA Astrophysics Data System (ADS)

Deterministic nonlinear dynamical processes are ubiquitous in nature. Chaotic sounds generated by such processes may appear irregular and random in waveform, but these sounds are mathematically distinguished from random stochastic sounds in that they contain deterministic short-time predictability in their temporal fine structures. We show that the human brain distinguishes deterministic chaotic sounds from spectrally matched stochastic sounds in neural processing and perception. Deterministic chaotic sounds, even without being attended to, elicited greater cerebral cortical responses than the surrogate control sounds after about 150 ms in latency after sound onset. Listeners also clearly discriminated these sounds in perception. The results support the hypothesis that the human auditory system is sensitive to the subtle short-time predictability embedded in the temporal fine structure of sounds.

Itoh, Kosuke; Nakada, Tsutomu

2013-04-01

254

Testing Machine for Short-Time Creep and Stress-Rupture Testing at 2000 to 2500°C  

Microsoft Academic Search

A testing machine is described in which a specimen contained within a water-jacketed vessel is heated in vacuum or in a gas atmosphere by a tantalum-tube resistance heater, and is then subjected to static tensile loads up to 100 000 psi. This machine is now in routine use at Los Alamos Scientific Laboratory for short-time creep and stress-rupture testing of

Morton C. Smith; D. M. Olson; Harry L. Brown

1957-01-01

255

OPERATIONAL NEAR REAL-TIME DERIVATION OF LAND SURFACE ALBEDO AND DOWNWELLING SHORT-WAVE RADIATION FROM MSG OBSERVATIONS  

Microsoft Academic Search

In the framework of the EUMETSAT Satellite Applica- tion Facility for Land Surface Analysis (Land-SAF) we develop surface albedo and short-wave radiation products which will be generated in near real-time from observa- tions provided by the MSG\\/SEVIRI instrument. The albedo algorithm exploits the diurnal variation of the illumination angle, which provides information on the angular variation of reflectance, in order

Bernhard Geiger; Laurent Franchist; Dulce Lajas; Jean-Louis Roujean

2004-01-01

256

Adaptive System Identification in the Short-Time Fourier Transform Domain Using Cross-Multiplicative Transfer Function Approximation  

Microsoft Academic Search

In this paper, we introduce cross-multiplicative transfer function (CMTF) approximation for modeling linear systems in the short-time Fourier transform (STFT) domain. We assume that the transfer function can be represented by cross-multiplicative terms between distinct subbands. We investigate the influence of cross-terms on a system identifier implemented in the STFT domain and derive analytical relations between the noise level, data

Yekutiel Avargel; Israel Cohen

2008-01-01

257

Numerical study of the effect of normalised window size, sampling frequency, and noise level on short time Fourier transform analysis  

NASA Astrophysics Data System (ADS)

Photonic Doppler velocimetry, also known as heterodyne velocimetry, is a widely used optical technique that requires the analysis of frequency modulated signals. This paper describes an investigation into the errors of short time Fourier transform analysis. The number of variables requiring investigation was reduced by means of an equivalence principle. Error predictions, as the number of cycles, samples per cycle, noise level, and window type were varied, are presented. The results were found to be in good agreement with analytical models.

Ota, T. A.

2013-10-01

258

Reliable genotyping of short tandem repeat loci without an allelic ladder using time-of-flight mass spectrometry  

Microsoft Academic Search

DNA separations which traditionally have been performed by slab gel or capillary electrophoresis, may now be conducted via\\u000a time-of-flight mass spectrometry (TOF-MS). The advantages of using a mass spectrometry approach for short tandem repeat (STR)\\u000a characterization include a dramatic increase in both the speed of analysis and the accuracy of mass measurements. We report\\u000a here typing of the STR loci

J. M. Butler; J. Li; T. A. Shaler; J. A. Monforte; C. H. Becker

1998-01-01

259

Numerical study of the effect of normalised window size, sampling frequency, and noise level on short time Fourier transform analysis.  

PubMed

Photonic Doppler velocimetry, also known as heterodyne velocimetry, is a widely used optical technique that requires the analysis of frequency modulated signals. This paper describes an investigation into the errors of short time Fourier transform analysis. The number of variables requiring investigation was reduced by means of an equivalence principle. Error predictions, as the number of cycles, samples per cycle, noise level, and window type were varied, are presented. The results were found to be in good agreement with analytical models. PMID:24182128

Ota, T A

2013-10-01

260

Real-time forecasting of short-term irrigation canal demands using a robust multivariate Bayesian learning model  

Microsoft Academic Search

In the lower Sevier River basin in Utah, the travel times between reservoir releases and arrival at irrigation canal diversions\\u000a limit the reservoir operation in enabling delivery changes, which may not be compatible with the on demand schedule in the\\u000a basin. This research presents a robust machine learning approach to forecast the short-term diversion demands for three irrigation\\u000a canals. These

Andres M. Ticlavilca; Mac McKee; Wynn R. Walker

261

Short-Time Scale Dynamic Failure Modes in a Through-Silicon-Via (TSV) Flip-Chip Configuration  

E-print Network

/O interconnections operating at several giga-Hertz clock speed inevitably suffer serious heat dissipation which raises important reliability concerns. Due to the miniaturized component size and complex structures in 3-D flip-chip packages, the possibility... analysis on short- time scale effects due to the practical deficiency of technology to capture waveforms propagating in a IC package at the giga-hertz level. Hence, a finite element analysis (FEA) model is required to "virtually" study the topic...

Huang, Chang-Chia

2010-10-12

262

Transient and secular radioactive equilibrium revisited  

E-print Network

The two definitions of radioactive equilibrium are revisited in this paper. The terms activity equilibrium and effective life equilibrium are proposed to take the place of currently used terms transient equilibrium and secular equilibrium. The proposed new definitions have the advantage of providing a clearer physics meaning. Besides the well known instant activity equilibrium, another class of exact effective life-time equilibrium is also discussed in this letter.

Zhang, Qinghui; Amols, Howard

2014-01-01

263

Human express saccades: extremely short reaction times of goal directed eye movements  

Microsoft Academic Search

Human subjects were asked to execute a saccade from a central fixation point to a peripheral target at the time of its onset. When the fixation point is turned off some time (˜ 200 ms) before target onset, such that there is a gap where subjects see nothing, the distribution of their saccadic reaction times is bimodal with one narrow

B. Fischer; E. Ramsperger

1984-01-01

264

Short duration winter-time performances of different passive solar systems  

NASA Astrophysics Data System (ADS)

The thermal performance of three full-sized adjoining rooms, each with a different south-facing passive feature, were monitored for two short periods during January to February and February to March. These rooms are Trombe wall cell, a control cell, and a direct gain cell in the NBS passive solar test facility. Data from 436 sensors were collected, including auxiliary energy supplied, continuous air infiltration, temperatures, solar radiation, and wind speed and direction. The test facility, instrumentation, data acquisition system, and procedures and test conditions are described. The performance of the three test cells are compared along with the values of average, controidal, and maximum and minimum air temperatures in the direct gain and Trombe wall cells. Results indicate that regardless of the magnitude of the stratification, the temperature recorded by the sensor placed in the vicinity of the centroid of the cell was nearly equal to the average value of the cell air temperature.

Mahajan, B. M.

1984-08-01

265

Short-time-scale (year) variations of petroleum fluids from the U.S. Gulf Coast  

NASA Astrophysics Data System (ADS)

Evolving short-term (less than 5 yr) compositional changes in hydrocarbon charge from some Eugene Island Block 330 (EI-330) wells are demonstrated. Storage, analytical, and production artifacts are shown to be minimal. In some wells, compositions remain constant from 1985 to 1993, whereas in others in the same reservoir, significant changes are observed. In some cases, temporal variability is greater than spatial variability. Maximum temporal change is strongest for specific compounds: toluene and C 6 to C 9 normal alkanes, but is also observed to a lesser extent for higher-molecular-weight components (up to n-C 32). Principal coordinate analysis shows the highest degree of overall temporal compositional change over an 8-yr period in the shallowest wells where there is also evidence of biodegradation. Small temporal compositional changes are also observed in two deeper wells that are below the thermal window favorable for biodegradation. An exception is an unusual oil, where a very large increase in toluene, as well as smaller changes in a number of n-alkanes, was observed in 1993. The ? 13C compound-specific isotopic signature of toluene, in addition to several other C 7-C 8 compounds in this oil, yields convincing evidence that it is related to the same family as other EI-330 oils and unlikely to be due to a drilling or laboratory contaminant. Minor isotopic differences in other C 7 compounds (1.5‰) are consistent with extensive gas washing of this oil. The short-term compositional changes in EI-330 oils are attributed to gas washing, which causes overprinting of biodegraded oils with light n-alkanes in shallower GA and HB reservoirs where oils are currently being biodegraded in situ. Patterns of smaller changes in heavier compounds in both shallower and deeper wells are also consistent with this interpretation.

Whelan, Jean K.; Eglinton, Lorraine; Kennicutt, Mahlon C.; Qian, Yaorong

2001-10-01

266

Thermalization time of thin metal film heated by short pulse laser  

NASA Astrophysics Data System (ADS)

Based on the hyperbolic two-step heat conduction model, using the Laplace transform and numerical inverse transform method (Riemann-sum approximation method), the thermal behaviour of thin metal films has been studied during femtosecond pulse laser heating. Also the thermalization time, which is the time for the electron gas and solid lattice to reach thermal balance, has been studied in detail. The values of thermalization time for silver (Ag), gold (Au), copper (Cu) and lead (Pb) are obtained. The effects of material parameters of the thin metal film on the thermalization time are considered for the four kinds of metals by changing one of the parameters and regarding the other parameters as constant. For a typical metal material, the order of the thermalization time is of the order of hundreds of picoseconds. The thermalization time decays exponentially with the increase of phonon-electron coupling factor or electron gas thermal conductivity and it increases linearly with the increase of the ratio of lattice heat capacity to electron gas heat capacity. However, the relaxation time of the electron gas has very little effect on the thermalization time.

Xu, Hong-Yu; Zhang, Yuan-Chong; Song, Ya-Qin; Chen, Dian-Yun

2004-10-01

267

FALSE DETERMINATIONS OF CHAOS IN SHORT NOISY TIME SERIES. (R828745)  

EPA Science Inventory

A method (NEMG) proposed in 1992 for diagnosing chaos in noisy time series with 50 or fewer observations entails fitting the time series with an empirical function which predicts an observation in the series from previous observations, and then estimating the rate of divergenc...

268

Test of the exponential decay law at short decay times using tau leptons  

Microsoft Academic Search

Quantum mechanics predicts an exponential distribution for the decay time of massive particles. However, deviations are expected for decay times shorter than about 10?13 s in models conjecturing the existence of hidden variables. Following a recent proposal, the decay length distribution of 5843 ? leptons decaying into 3 charged particles was analyzed in search of such a deviation. The deviation

Gideon Alexander; J. Allison; N. Altekamp; K A Ametewee; K. J. Anderson; S. Anderson; S. Arcelli; D A Axen; Georges Azuelos; A. H. Ball; E. Barberio; R. J. Barlow; R. Bartoldus; J Richard Batley; G. Beaudoin; J. Bechtluft; G. A. Beck; C. Beeston; T. Behnke; A. N. Bell; K. W. Bell; G. Bella; Stanislaus Cornelius Maria Bentvelsen; P. Berlich; Siegfried Bethke; O. Biebel; Ian J Bloodworth; J. E. Bloomer; P. Bock; H. M. Bosch; M. Boutemeur; B. T. Bouwens; S. Braibant; P G Bright-Thomas; R. M. Brown; Helfried J Burckhart; C. Burgard; R. Bürgin; P. Capiluppi; R. K. Carnegie; A. A. Carter; J. R. Carter; C. Chang Y; C. Charlesworth; D. G. Charlton; D. Chrisman; S. L. Chu; P. E. L. Clarke; S. G. Clowes; I. Cohen; J. E. Conboy; O. C. Cooke; M. Cuffiani; S. Dado; C. Dallapiccola; G. M. Dallavalle; C L Darling; S. De Jong; L. A. del Pozo; M. S. Dixit; E. do Couto e Silva; E. Duchovni; G. Duckeck; I. P. Duerdoth; U. C. Dunwoody; J. E. G. Edwards; P. G. Estabrooks; H. G. Evans; Franco Luigi Fabbri; B. Fabbro; P. Fath; F. Fiedler; M. Fierro; Margret Fincke-Keeler; H. M. Fischer; R. Folman; D. G. Fong; M. Foucher; H. Fukui; A. Fürtjes; P. Gagnon; A. Gaidot; J. W. Gary; J. Gascon; S. M. Gascon-Shotkin; N. I. Geddes; C. Geich-Gimbel; S. W. Gensler; F. X. Gentit; T. Geralis; G. Giacomelli; P. Giacomelli; R. Giacomelli; V. Gibson; W. R. Gibson; D. M. Gingrich; J. Goldberg; M. J. Goodrick; W. Gorn; C. Grandi; E. Gross; C. Hajdu; G. G. Hanson; M. Hansroul; M. Hapke; C. K. Hargrove; P. A. Hart; C. Hartmann; M. Hauschild; C. M. Hawkes; R. Hawkings; Richard J Hemingway; G. Herten; R. D. Heuer; M. D. Hildreth; J. C. Hill; S. J. Hillier; T. Hilse; P. R. Hobson; D. Hochman; R James Homer; A. K. Honma; D. Horváth; R. Howard; R. E. Hughes-Jones; D. E. Hutchcroft; P. Igo-Kemenes; D. C. Imrie; A. Jawahery; P. W. Jeffreys; H. Jeremie; Martin Paul Jimack; A. Joly; M. Jones; R. W. L. Jones; U. Jost; P. Jovanovic; D A Karlen; T. Kawamoto; Richard K Keeler; R. G. Kellogg; B. W. Kennedy; B. J. King; J. King; J. Kirk; S. Kluth; T. Kobayashi; M. Kobel; D. S. Koetke; T. P. Kokott; S. Komamiya; R V Kowalewski; T. Kress; P. Krieger; J. von Krogh; P. Kyberd; G. D. Lafferty; H. Lafoux; R. Lahmann; W. P. Lai; D. Lanske; J. Lauber; J. G. Layter; A. M. Lee; E. Lefebvre; Daniel Lellouch; J. Letts; L. Levinson; C. Lewis; S. L. Lloyd; F. K. Loebinger; G. D. Long; B. Lorazo; Michael J Losty; J. Ludwig; A. Luig; A. Malik; M. Mannelli; S. Marcellini; C. Markus; A. J. Martin; J. P. Martin; G. Martinez; T. Mashimo; W. Matthews; P. Mättig; W. J. McDonald; J A McKenna; E. A. Mckigney; T. J. McMahon; A. I. McNab; F. Meijers; S. Menke; F. S. Merritt; H. Mes; J. Meyer; Aldo Michelini; G. Mikenberg; D. J. Miller; R. Mir; W. Mohr; A. Montanari; T. Mori; M. Morii; U. Müller; B. Nellen; B. Nijjhar; R. Nisius; S. W. O'Neale; F. G. Oakham; F. Odorici; H. O. Ogren; N. J. Oldershaw; T. Omori; C. J. Oram; M. J. Oreglia; S. Orito; M. Palazzo; J. Pálinkás; F. M. Palmonari; J. P. Pansart; G. Pásztor; J. R. Pater; G. N. Patrick; M. J. Pearce; P. D. Phillips; J. E. Pilcher; J L Pinfold; D. E. Plane; P R Poffenberger; B. Poli; A. Posthaus; T. W. Pritchard; H. Przysiezniak; D. L. Rees; D. Rigby; M. G. Rison; S. A. Robins; N L Rodning; J. M. Roney; E. Ros; A. M. Rossi; M. Rosvick; P. Routenburg; Y. Rozen; K. Runge; O. Runolfsson; D. R. Rust; R. Rylko; E Sarkisyan-Grinbaum; M. Sasaki; C. Sbarra; A. D. Schaile; O. Schaile; F. Scharf; P. Scharff-Hansen; P. Schenk; B. Schmitt; M. Schröder; H. C. Schultz-Coulon; M. Schulz; P. Schütz; J. Schwiening; W. G. Scott; T. G. Shears; B. C. Shen; C. H. Shepherd-Themistocleous; P. Sherwood; G. P. Siroli; A. Sittler; A. Skillman; A. Skuja; A. M. Smith; T. J. Smith; G. A. Snow; Randall J Sobie; S. Söldner-Rembold; R. W. Springer; M. Sproston; A. Stahl; M. Starks; C. Stegmann; K. Stephens; J. Steuerer; B. Stockhausen; D. Strom; F. Strumia; P. Szymanski; R. Tafirout; H. Takeda; P. Taras; S. Tarem; M. Tecchio; N. Tesch; M. A. Thomson; E. von Törne; S. Towers; M. Tscheulin; T. Tsukamoto; E. Tsur; A. S. Turcot; M. F. Turner-Watson; P. Utzat; R. Van Kooten; G. Vasseur; P. Vikas; M G Vincter; E. H. Vokurka; F. Wäckerle; A. Wagner; D. L. Wagner; C. P. Ward; D. R. Ward; J. J. Ward; P. M. Watkins; A. T. Watson; N. K. Watson; P. Weber; P. S. Wells; N. Wermes; B. Wilkens; G. W. Wilson; J. A. Wilson; T. Wlodek; G. Wolf; S A Wotton; T. R. Wyatt; S M Xella; S. Yamashita; G. Yekutieli; V. Zacek

1996-01-01

269

Use of extremely short F?rster resonance energy transfer probes in real-time polymerase chain reaction  

PubMed Central

Described in the article is a new approach for the sequence-specific detection of nucleic acids in real-time polymerase chain reaction (PCR) using fluorescently labeled oligonucleotide probes. The method is based on the production of PCR amplicons, which fold into dumbbell-like secondary structures carrying a specially designed ‘probe-luring’ sequence at their 5? ends. Hybridization of this sequence to a complementary ‘anchoring’ tail introduced at the 3? end of a fluorescent probe enables the probe to bind to its target during PCR, and the subsequent probe cleavage results in the florescence signal. As it has been shown in the study, this amplicon-endorsed and guided formation of the probe-target duplex allows the use of extremely short oligonucleotide probes, up to tetranucleotides in length. In particular, the short length of the fluorescent probes makes possible the development of a ‘universal’ probe inventory that is relatively small in size but represents all possible sequence variations. The unparalleled cost-effectiveness of the inventory approach is discussed. Despite the short length of the probes, this new method, named Angler real-time PCR, remains highly sequence specific, and the results of the study indicate that it can be effectively used for quantitative PCR and the detection of polymorphic variations. PMID:24013564

Kutyavin, Igor V.

2013-01-01

270

Short communication: Decrease in rumination time as an indicator of the onset of calving.  

PubMed

The aim of this study was to investigate whether rumination time (RT) is affected by the onset of calving. The relationship between both feeding time and dry matter intake (DMI) to the onset of calving was also examined. In addition, the correlation between feeding behavior characteristics, described here as RT, feeding time, and DMI, was evaluated. Under test conditions, the feeding behavior of pregnant Holstein cows was recorded from the time when they were moved into calving pens (usually 7 to 5d prepartum) until the onset of calving. Feeding time and DMI were recorded by automatic feed bins; RT was measured continuously by a measuring halter based on electromyography (DairyCheck; BITSz Engineering GmbH, Zwickau, Germany), which constitutes a new approach regarding feeding behavior detection. Data analysis related to the final 72 h, before the onset of calving, which were divided into twelve 6-h blocks. The last 6h (one 6-h block) before calving were compared with the 72- to 7-h time frame (11 times 6-h blocks) before calving, which was defined as the reference period. For this time period, feeding behavior data for 17 cows was fully available, which was the precondition for data analysis. In the final 6h before imminent birth, RT was significantly reduced. During this time, it was found that the mean minimum RT was 69.9 ± 28.5 min/6h compared with the mean RT of 95.5 ± 30.8 min/6h in the reference period. The average decrease in RT was 27% (25.6 min/6h). In addition, feeding time and DMI were significantly reduced. The average decrease in feeding time was 57% (20.8 min/6h), and in DMI it was 56% (1.9 kg/6h). High correlation coefficients between feeding behavior characteristics were only found between feeding time and DMI. Values of feeding behavior among cows were characterized by high variability. Recording RT can serve as a useful tool for predicting the timing of birth for dairy cows, but further research is necessary. PMID:24612813

Büchel, S; Sundrum, A

2014-05-01

271

Time-dependent intensity and phase measurements of ultrashort laser pulses as short as 10 fs  

SciTech Connect

Frequency-Resolved Optical Gating (FROG) measures the time-dependent intensity and phase of an ultrashort laser pulse. Using FROG, we have tested theories for the operation of sub{minus}10 fs laser oscillators.

DeLong, K.W.; Fittinghoff, D.N.; Ladera, C.L.; Trebino, R. [Sandia National Labs., Livermore, CA (United States); Taft, G.; Rundquist, A.; Murnane, M.M.; Kapteyn, H.C. [Washington State Univ., Pullman, WA (United States). Dept. of Physics; Christov, I.P. [Faculty of Physics, Sofia Univ., Sofia (Bulgaria)

1995-05-01

272

Short time scale thermal mechanical shock wave propagation in high performance microelectronic packaging configuration  

E-print Network

predict vastly different results in the vicinity of the heat source but that the differences diminish within a larger time window. Results from both theories indicate that the rapid thermal-mechanical waves cause high frequency, broadband stress waves...

Nagaraj, Mahavir

2004-11-15

273

Short-term sandbar variability based on video imagery: Comparison between Time-Average and Time-Variance techniques  

USGS Publications Warehouse

Time-exposure intensity (averaged) images are commonly used to locate the nearshore sandbar position (xb), based on the cross-shore locations of maximum pixel intensity (xi) of the bright bands in the images. It is not known, however, how the breaking patterns seen in Variance images (i.e. those created through standard deviation of pixel intensity over time) are related to the sandbar locations. We investigated the suitability of both Time-exposure and Variance images for sandbar detection within a multiple bar system on the southern coast of Brazil, and verified the relation between wave breaking patterns, observed as bands of high intensity in these images and cross-shore profiles of modeled wave energy dissipation (xD). Not only is Time-exposure maximum pixel intensity location (xi-Ti) well related to xb, but also to the maximum pixel intensity location of Variance images (xi-Va), although the latter was typically located 15m offshore of the former. In addition, xi-Va was observed to be better associated with xD even though xi-Ti is commonly assumed as maximum wave energy dissipation. Significant wave height (Hs) and water level (??) were observed to affect the two types of images in a similar way, with an increase in both Hs and ?? resulting in xi shifting offshore. This ??-induced xi variability has an opposite behavior to what is described in the literature, and is likely an indirect effect of higher waves breaking farther offshore during periods of storm surges. Multiple regression models performed on xi, Hs and ?? allowed the reduction of the residual errors between xb and xi, yielding accurate estimates with most residuals less than 10m. Additionally, it was found that the sandbar position was best estimated using xi-Ti (xi-Va) when xb was located shoreward (seaward) of its mean position, for both the first and the second bar. Although it is unknown whether this is an indirect hydrodynamic effect or is indeed related to the morphology, we found that this behavior can be explored to optimize sandbar estimation using video imagery, even in the absence of hydrodynamic data. ?? 2011 Elsevier B.V..

Guedes, R.M.C.; Calliari, L.J.; Holland, K.T.; Plant, N.G.; Pereira, P.S.; Alves, F.N.A.

2011-01-01

274

Optimization of counting times for short-lived gamma-ray emitters in air filter samples.  

PubMed

A methodology for the optimization of the counting times in a series of measurements of gamma-ray emitters in air filters is presented. In the optimal measurement regime in measurements of all the filters in a batch, the same minimum detectable activity is attained. It is shown how the number of filters, the properties of the gamma-ray emitter and the equipment influence the measurement time of the batch of filters and the minimum detectable activity attained. PMID:16554169

Korun, M

2006-01-01

275

Parvalbumin tunes spike-timing and efferent short-term plasticity in striatal fast spiking interneurons  

PubMed Central

Striatal fast spiking interneurons (FSIs) modulate output of the striatum by synchronizing medium-sized spiny neurons (MSNs). Recent studies have broadened our understanding of FSIs, showing that they are implicated in severe motor disorders such as parkinsonism, dystonia and Tourette syndrome. FSIs are the only striatal neurons to express the calcium-binding protein parvalbumin (PV). This selective expression of PV raises questions about the functional role of this Ca2+ buffer in controlling FSI Ca2+ dynamics and, consequently, FSI spiking mode and neurotransmission. To study the functional involvement of FSIs in striatal microcircuit activity and the role of PV in FSI function, we performed perforated patch recordings on enhanced green fluorescent protein-expressing FSIs in brain slices from control and PV?/? mice. Our results revealed that PV?/? FSIs fired more regularly and were more excitable than control FSIs by a mechanism in which Ca2+ buffering is linked to spiking activity as a result of the activation of small conductance Ca2+-dependent K+ channels. A modelling approach of striatal FSIs supports our experimental results. Furthermore, PV deletion modified frequency-specific short-term plasticity at inhibitory FSI to MSN synapses. Our results therefore reinforce the hypothesis that in FSIs, PV is crucial for fine-tuning of the temporal responses of the FSI network and for the orchestration of MSN populations. This, in turn, may play a direct role in the generation and pathology-related worsening of motor rhythms. PMID:23551945

Orduz, David; Bischop, Don Patrick; Schwaller, Beat; Schiffmann, Serge N; Gall, David

2013-01-01

276

Revisiting Dialogues and Monologues  

ERIC Educational Resources Information Center

In educational discourse dialogue tends to be viewed as being (morally) superior to monologue. When we look at them as basic forms of communication, we find that dialogue is a two-way, one-to-one form and monologue is a one-way, one-to-many form. In this paper I revisit the alleged (moral) superiority of dialogue. First, I problematize certain…

Kvernbekk, Tone

2012-01-01

277

An investigation of short period oscillations of the solar irradiance and their time variations  

NASA Technical Reports Server (NTRS)

Measurements of solar irradiance fluctuations by the Active Cavity Radiometer (ACRIM) instrument onboard the Solar Maximum Mission (SMM) show variations on a time scale of about 5 minutes due to solar p-mode oscillations, as well as longer-term variations related to solar magnetic activity. The question was studied whether the p-mode frequencies change with time as a result of changing solar structure associated with the activity cycle. The ACRIM data on SMM are particularly well-suited for this purpose, because the instrument operated continuously from February 1980 to December 1980 and again from May 1984 to the present. The main activity entailed a detailed study of the observational data to determine if a change in the p-mode frequencies is evident from the time of solar maximum to that of solar minimum. It was concluded that the measured eigenfrequencies were significantly higher during the 1980 time frame than during the 1984 to 1986 time frame. The conclusion that there is significant change in the eigenfrequencies with the activity cycle remains only tentative, and needs confirmation from analysis of more data during the upcoming solar maximum.

Noyes, Robert W.

1987-01-01

278

Potential denitrification and N2O efflux from riparian soils during short-time flooding  

NASA Astrophysics Data System (ADS)

Denitrification can contribute significantly to the filter function of soils because it leads to permanent removal of nitrate. Denitrification has been intensively studied in wetlands characterized by seasonal wet-dry cycles and in riparian buffer zones between agricultural land and rivers. Less attention has been paid to the effects of overbank flooding in river floodplains, in particular to short terms effect of flood pulses. We monitored denitrification potential, N2O efflux and related parameters in soils of a restored reach of the Alpine river Thur in northeastern Switzerland during and after flashy flood events. The study was part of the interdisciplinary project cluster RECORD, which was initiated to advance the mechanistic understanding of coupled hydrological and ecological processes in river corridors. The studied river reach comprised the following three functional processing zones (FPZ) representing a lateral successional gradient with decreasing hydrological connectivity (i.e. decreasing flooding frequency and duration). (i) The grass zone developed naturally on a gravel bar after restoration of the channelized river section (mainly colonized by canary reed grass Phalaris arundinacae). The soil is composed of up to 80 cm thick fresh sediments trapped and stabilized by the grass roots. (ii) The bush zone is composed of young willow trees (Salix viminalis) planted during restoration to stabilize older overbank deposits. (iii) The mixed forest is a mature riparian hardwood forest developed on older overbank sediments with ash and maple as dominant trees. The study period was between April and October 2009 including two flood events in June and July. The first flood inundated the grass zone and lower part of the willow bush while the second bigger flood swept through all the FPZs. Topsoil samples were taken from four spatial replicates in each FPZ mostly biweekly and with higher frequency following the floods. Potential denitrification was measured as denitrifier enzyme activity (DEA) and substrate limitation was assessed by the same assay but without addition of glucose and nitrate. Over the entire observation period, soil moisture was the main controlling factor of DEA in all FPZ (correlation between DEA and gravimetric water content with R = 0.74, 0.61 and 0.47 for grass zone, willow bush and mixed forest, respectively, at p<0.01). Considering extractable nitrate and the results from the denitrification assay without nitrate and glucose we conclude that there was some substrate limitation but it was not severe. During the flooding events, DEA responded instantaneously to the changes in soil moisture. Particularly strong denitrification "pulses" were observed 1 to 2 days after peak floods in the grass zone, while the scale of change decreased with distance from the river. A severe substrate limitation in the grass zone was indicated 5 days after the peak of the second flood. N2O emissions did not correlate with DEA. High N2O emissions were measured in the grass zone during the entire period of relatively high soil moisture encompassing the two floods with maximum values shortly after water level fell below the overbank sediment. Smaller N2O emissions during complete or partial saturation of the sediments indicated a smaller proportion of denitrification related N2O vs. N2. In addition, a comparison with the composition of soil solution collected in-situ (in particular nitrate and DOC) will be presented for additional insight into controls and limitations of denitrification.

Shrestha, Juna; Niklaus, Pascal; Frossard, Emmanuel; Tockner, Klement; Luster, Jörg

2010-05-01

279

Spatial and Time Coincidence Detection of the Decay Chain of Short-Lived Radioactive Nuclei  

SciTech Connect

The quantum counting position sensitive pixel detector Timepix with per-pixel energy and time resolution enables to detect radioactive ions and register the consecutive decay chain by simultaneous position-and time-correlation. This spatial and timing coincidence technique in the same sensor is demonstrated by the registration of the decay chain {sup 8}He{yields}{sup {beta} 8}Li and {sup 8}Li{yields}{sup {beta}-} {sup 8}Be{yields}{alpha}+{alpha} and by the measurement of the {beta} decay half-lives. Radioactive ions, selectively obtained from the Lohengrin fission fragment spectrometer installed at the High Flux Reactor of the ILL Grenoble, are delivered to the Timepix silicon sensor where decays of the implanted ions and daughter nuclei are registered and visualized. We measure decay lifetimes in the range {>=}{mu}s with precision limited just by counting statistics.

Granja, Carlos; Jakubek, Jan; Platkevic, Michal; Pospisil, Stanislav [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Koester, Ulli [Institute Laue Langevin, 6 rue Jules Horowitz, F-38042 Grenoble Cedex 9 (France)

2010-08-04

280

SHORT COMMUNICATION Effects of time and rainfall on PCR success using DNA  

E-print Network

was to determine the length of time a fecal pellet from a Sitka black-tailed deer (Odocoileus hemionus sitkensis of DNA from ungulate pellets. Keywords DNA degradation Á Feces Á Microsatellites Á Odocoileus hemionus with limited road access, such as Sitka black-tailed deer (Odo- coileus hemionus sitkensis) in the temperate

281

Performance impact on nuclear thermal propulsion of piloted Mars missions with short transit times  

NASA Technical Reports Server (NTRS)

The requirements of nuclear thermal propulsion (NTP) are examined with respect to a specific mission scenario derived from Stafford Committee recommendations. The recommended mission scenario is a split/sprint opposition mission which includes a piloted vehicle and a cargo vehicle, and the baseline mission is developed from a reference trajectory. Key mision parameters are developed from the baseline mission, including engine-thrust levels, mission opportunity, and engine burn-time requirements. The impact of engine failure is also considered in terms of burn-time requirements, and other mission-performance issues considered include propulsion-technology assumptions, triple-perigee earth-departure burns, and Mars parking-orbit selection. The engine requirements call for a 50-75-klb engine-thrust level, maximum single burn time of 0.6 hours, and a maximum total-mission burn time of 1.7 hours. For a crew of 6, a 475-day total-mission trip with a 90-day stay at Mars is possible.

Wickenheiser, T. J.; Gessner, K. S.; Alexander, S. W.

1991-01-01

282

Frequency-selective quantification of short-echo time Magnetic Resonance spectra  

E-print Network

they share the same model, are modeled using a database of metabolite signals. Quantification of SE time MR spectra is complicated by broad baseline signal contributions, resonance line-shape distortions the unwanted com- ponents. This paper considers three types of unwanted or nui- sance components: the baseline

283

Characterizing bioterrorist attacks from a short time series of diagnosed patient data -A Bayesian approach  

E-print Network

infected, the time of infection, and the average dose received, is important when planning a medical that these data are usually sufficient, especially if the model of the outbreak used in the inverse problem problem is only a partially accurate representation of the outbreak. We find that while

Ray, Jaideep

284

High protective, environmental friendly and short-time developed conversion coatings for aluminium alloys  

Microsoft Academic Search

There are a variety of procedures, described in the bibliography, for producing conversion coatings using salts of lanthanide elements, and the coatings obtained by means of some of these procedures show acceptable levels of protection. Nevertheless, the principal limitation usually presented by these procedures is the excessively prolonged treatment times required to achieve such levels of protection. This therefore limits

M. Bethencourt; F. J. Botana; M. J. Cano; M. Marcos

2002-01-01

285

Short Running Title: Implementing RealTime Semantics Contact Author: Gerald Luttgen  

E-print Network

¨uttgen, Implementing Real­Time Semantics 1 1 INTRODUCTION A variety of formal approaches have been introduced, and a verification method. Specification languages provide a syntactic means for describing (abstractions of) real­world systems and can be of graph­ ical nature (e.g. Statecharts [Harel 1987]), term­based (e.g., process

Cleaveland, Rance

286

Short Running Title: Implementing Real-Time Semantics Contact Author: Gerald Luttgen  

E-print Network

of real-world systems and can be of graph- ical nature e.g. Statecharts Harel 1987 , term-based e precisely, syntactic models are compiled to labeled transition systems which describe the real-world system, Implementing Real-Time Semantics 1 1 INTRODUCTION A variety of formal approaches have been introduced

Lüttgen, Gerald

287

Transcription factor target prediction using multiple short expression time series from Arabidopsis thaliana  

PubMed Central

Background The central role of transcription factors (TFs) in higher eukaryotes has led to much interest in deciphering transcriptional regulatory interactions. Even in the best case, experimental identification of TF target genes is error prone, and has been shown to be improved by considering additional forms of evidence such as expression data. Previous expression based methods have not explicitly tried to associate TFs with their targets and therefore largely ignored the treatment specific and time dependent nature of transcription regulation. Results In this study we introduce CERMT, Covariance based Extraction of Regulatory targets using Multiple Time series. Using simulated and real data we show that using multiple expression time series, selecting treatments in which the TF responds, allowing time shifts between TFs and their targets and using covariance to identify highly responding genes appear to be a good strategy. We applied our method to published TF – target gene relationships determined using expression profiling on TF mutants and show that in most cases we obtain significant target gene enrichment and in half of the cases this is sufficient to deliver a usable list of high-confidence target genes. Conclusion CERMT could be immediately useful in refining possible target genes of candidate TFs using publicly available data, particularly for organisms lacking comprehensive TF binding data. In the future, we believe its incorporation with other forms of evidence may improve integrative genome-wide predictions of transcriptional networks. PMID:18021423

Redestig, Henning; Weicht, Daniel; Selbig, Joachim; Hannah, Matthew A

2007-01-01

288

Broadband extreme-ultraviolet survey spectrometer for short-time-scale experiments  

E-print Network

to record extreme-UV impurity spectra in a magnetic-fusion-research device. To simplify the vacuum system, light is passed out of the spectrom- eter's vacuum to the detector with a sodium the spectrometer's vacuum. In- creased time resolution is achieved with a simple modification of the electronics

Wisconsin at Madison, University of

289

Characterizing ecosystem-atmosphere interactions from short to interannual time scales  

NASA Astrophysics Data System (ADS)

Characterizing ecosystem-atmosphere interactions in terms of carbon and water exchange on different time scales is considered a major challenge in terrestrial biogeochemical cycle research. The respective time series currently comprise an observation period of up to one decade. In this study, we explored whether the observation period is already sufficient to detect cross-relationships between the variables beyond the annual cycle, as they are expected from comparable studies in climatology. We investigated the potential of Singular System Analysis (SSA) to extract arbitrary kinds of oscillatory patterns. The method is completely data adaptive and performs an effective signal to noise separation. We found that most observations (Net Ecosystem Exchange, NEE, Gross Primary Productivity, GPP, Ecosystem Respiration, Reco, Vapor Pressure Deficit, VPD, Latent Heat, LE, Sensible Heat, H, Wind Speed, u, and Precipitation, P) were influenced significantly by low-frequency components (interannual variability). Furthermore, we extracted a set of nontrivial relationships and found clear seasonal hysteresis effects except for the interrelation of NEE with Global Radiation (Rg). SSA provides a new tool for the investigation of these phenomena explicitly on different time scales. Furthermore, we showed that SSA has great potential for eddy covariance data processing, since it can be applied as a novel gap filling approach relying on the temporal correlation structure of the time series structure only.

Mahecha, M. D.; Reichstein, M.; Lange, H.; Carvalhais, N.; Bernhofer, C.; Grünwald, T.; Papale, D.; Seufert, G.

2007-09-01

290

Non-destructive measurement of stem water content by time domain reflectometry using short probes  

Microsoft Academic Search

Time Domain Reflectometry (TDR) has previously been used to determine the water content of soils. Here, TDR is assessed as a method of tracking the seasonal change in water content of the stems of mature trees (Pinus sylvestris L.). The longer probes used for soil were replaced by 50 mm probes, inserted radially into the stems at 1 m above

J. Irvine; J. Grace

2010-01-01

291

Effects of time-of-day and partial sleep deprivation on short-term maximal performances of judo competitors.  

PubMed

This study assessed the effects of partial sleep deprivation on short-term maximal performances of judokas in the morning and afternoon of the following day. In a randomized design, 12 judokas completed the maximal voluntary contraction, the handgrip, and the Wingate tests before and after a judo combat. Measurements were performed at 09:00 and 16:00 hours after a reference-normal sleep night and 2 conditions of 4-hour partial sleep deprivation timed at the beginning (SDB) or at the end of the night (SDE). The results showed that muscle power and strength were significantly higher at 16:00 than 09:00 hours (p < 0.05). These diurnal variations disappeared after SDB and SDE and after the combat. In addition, SDE resulted in significant decreases of short-term maximal performance in the afternoon (p < 0.01). In conclusion, SDE decreased muscle strength and power at 16:00 hours and, therefore, might have blunted the diurnal variations of short-term maximal exercise. Thus, early rising is more detrimental than late bedtime to muscle strength and power for judo athletes when competitions are scheduled in the afternoon hours. PMID:23974210

Souissi, Nizar; Chtourou, Hamdi; Aloui, Asma; Hammouda, Omar; Dogui, Mohamed; Chaouachi, Anis; Chamari, Karim

2013-09-01

292

HARE++: Hardware Assisted Reverse Execution Revisited Ioannis Doudalis  

E-print Network

HARE++: Hardware Assisted Reverse Execution Revisited Ioannis Doudalis Georgia Institute- nique. HARE++ reduces the reverse execution latency by 3.5-4 times on average compared to HARE-accelerators. 1. Introduction Debugging is a time consuming, yet important, process during soft- ware development

Prvulovic, Milos

293

Study on Performance Parameters of the Plasma Source for a Short-Conduction-Time Plasma Opening Switch  

NASA Astrophysics Data System (ADS)

Plasma source performance parameters, including plasma ejection density and velocity, greatly affect the operation of a short-conduction-time plasma opening switch (POS). In this paper, the plasma source used in the POS of Qiangguang I generator is chosen as the study object. At first the POS working process is analyzed. The result shows that the opening performance of the POS can be improved by increasing the plasma ejection velocity and decreasing the plasma density. The influence of the cable plasma gun structure and number on the plasma ejection parameters is experimentally investigated with two charge collectors. Finally a semi-empirical model is proposed to describe the experimental phenomenon.

Luo, Weixi; Zeng, Zhengzhong; Wang, Liangping; Lei, Tianshi; Hu, Yixiang; Huang, Tao; Sun, Tieping

2012-12-01

294

The use of short-echo-time 1 H MRS for childhood cerebellar tumours prior to histopathological diagnosis  

Microsoft Academic Search

Background  Proton magnetic resonance spectroscopy (MRS) measures concentrations of metabolites in vivo and provides a powerful method\\u000a for identifying tumours. MRS has not entered routine clinical use partly due to the difficulty of analysing the spectra.\\u000a \\u000a \\u000a \\u000a Objective  To create a straightforward method for interpreting short-echo-time MRS of childhood cerebellar tumours.\\u000a \\u000a \\u000a \\u000a Materials and methods  Single-voxel MRS (1.5-T Siemens Symphony NUM4, TR\\/TE 1,500\\/30 ms) was performed

Lisa M. Harris; Nigel Davies; Lesley MacPherson; Katharine Foster; Shaheen Lateef; Kal Natarajan; Spyridon Sgouros; Marie-Anne Brundler; Theodoros N. Arvanitis; Richard G. Grundy; Andrew C. Peet

2007-01-01

295

New short-time alignment technique for 70-meter antenna surface panels  

NASA Technical Reports Server (NTRS)

With severely limited field modification time for upgrading the 64-m antenna to 70-m diameter, a new shorter time method for aligning the surface panels of the main reflector was needed. For each target on the surface panel, both distance (or range) and elevation angle measurements are made. A new technique for setting the surface panels at zenith look has been devised. This article describes the software required to convert the computed target distortions obtained from the JPL-IDEAS structural analysis computer program (defining the gravity load change from a 45-deg elevation angle to zenith look) into the theodolite reading at zenith look. The technique results in a perfectly shaped reflector at the 45-deg rigging elevation, with acceptable surface error tolerance.

Katow, M. S.

1986-01-01

296

Short time variability of solar corona during recent solar cycle minimum  

NASA Astrophysics Data System (ADS)

Sphinx is the X-ray spectrophotometer designed to measure X-ray emission from the Sun in the energy range between 0.8 keV and 15 keV. The instrument is placed onboard Russian KORONAS-PHOTON satellite launched on January 30, 2009. In this paper we present the observations of coronal emission obtained between March-April and August-September 2009, i.e. the times towards the end of the last, very prolonged and deep minimum of solar activity. Prompt analysis of SphinX spectra reveal the variability of the average coronal plasma charac-teristics like the temperature and emission measure. These data are used to compare SphinX and GOES measurements, for selected times. Examples of many sub/microflare events with maxima of the X-ray flux, observed much below the GOES sensitivity threshold level will be presented.

Siarkowski, Marek; Gryciuk, Magdalena; Gburek, Szymon; Sylwester, Janusz; Sylwester, Barbara; Kepa, Anna; Buczkowska, Agnieszka; Kowalinski, Miroslaw

297

Time estimation and concurrent nontemporal processing: Specific interference from short-term-memory demands  

Microsoft Academic Search

Previous studies have shown that the effect of concurrent nontempcraLprocessmg on time astimation may vary depending on the\\u000a level of difficulty of the nontemporal task. This is commonly interpreted within the context of so-called distraction\\/interruption\\u000a models of temporal processing, which propose that as concurrent task difficulty or complexity is increased, temporal processing\\u000a receives less attention. We hypothesize that the effect

C. Fortin; R. Rousseau; P. Bourque; E. Kirouac

1993-01-01

298

Short-time-scale variations in flow speed and behavior, Helheim Glacier, East Greenland  

Microsoft Academic Search

We have obtained a suite of detailed geophysical observations, spanning two summer seasons, at Helheim Glacier, East Greenland. This interdisciplinary dataset includes geodetic, seismic, radar, and lidar observations, in addition to tidal, weather, and satellite remote-sensing data. Continuous high-rate GPS observations from a period of 50 days in July--August, 2007, extend a 60-day summer-season time series obtained in 2006. Reoccupation

M. Nettles; T. B. Larsen; P. Elósegui; A. P. Ahlstrøm; J. L. Davis; J. de Juan; G. EkstrÖM; R. Forsberg; G. S. Hamilton; S. A. Khan; M. L. Andersen; L. A. Stearns; L. Stenseng

2007-01-01

299

Kinetic study of thermal inactivation of potato peroxidase during high-temperature short-time processing  

Microsoft Academic Search

Thermal inactivation curves for peroxidase in potato extracts were determined in the range of 100 to 140°C for 10 to 100 sec.\\u000a The capillary tube method was used to obtain isothermal conditions. The come-up time for the capillary tubes was accurately\\u000a calculated by analysis method by which thermal inactivation kinetics of enzymes in relation to high temperature processing\\u000a would be

Bo Yu; Zhengyu Jin; Li Deng; Xueming Xu; Lifeng He; Jinpeng Wang; Yaoqi Tian; Hanqing Chen

2010-01-01

300

Coherent averaging of the passive fathometer response using short correlation time  

E-print Network

experimental data.1­3,8,9 The technique relies on surface generated noise from wind and waves.10,11 Ship- ping s and, for correlation times less than a few seconds, the observed sig- nal-to-noise ratio (SNR) agrees-correlation of ambient noise data from a drifting vertical array, has been the subject of much discussion in recent years

Gerstoft, Peter

301

Optimal Short-Time Acquisition Schemes in High Angular Resolution Diffusion-Weighted Imaging  

PubMed Central

This work investigates the possibilities of applying high-angular-resolution-diffusion-imaging- (HARDI-) based methods in a clinical setting by investigating the performance of non-Gaussian diffusion probability density function (PDF) estimation for a range of b-values and diffusion gradient direction tables. It does so at realistic SNR levels achievable in limited time on a high-performance 3T system for the whole human brain in vivo. We use both computational simulations and in vivo brain scans to quantify the angular resolution of two selected reconstruction methods: Q-ball imaging and the diffusion orientation transform. We propose a new analytical solution to the ODF derived from the DOT. Both techniques are analytical decomposition approaches that require identical acquisition and modest postprocessing times and, given the proposed modifications of the DOT, can be analyzed in a similar fashion. We find that an optimal HARDI protocol given a stringent time constraint (<10?min) combines a moderate b-value (around 2000?s/mm2) with a relatively low number of acquired directions (>48). Our findings generalize to other methods and additional improvements in MR acquisition techniques. PMID:23554808

Prckovska, V.; Achterberg, H. C.; Bastiani, M.; Pullens, P.; Balmashnova, E.; ter Haar Romeny, B. M.; Vilanova, A.; Roebroeck, A.

2013-01-01

302

Real-time manned simulation of advanced terminal area guidance concepts for short-haul operations  

NASA Technical Reports Server (NTRS)

A real-time simulation was conducted of three-dimensional area navigation and four-dimensional area navigation equipped (STOL) aircraft operating in a high-density terminal area traffic environment. The objectives were to examine the effects of 3D RNAV and 4D RNAV equipped aircraft on the terminal area traffic efficiency, and to examine the performance of an air traffic control system concept and associated controller display proposed for use with advanced RNAV systems. Three types of STOL aircraft were simulated each with different performance capabilities. System performance was measured in both the 4D mode and in a 3D mode; the 3D mode, used as a baseline, was simply the 4D mode less any time specification. The results show that communications workload in the 4D mode was reduced by about 35 percent compared to the 3D, while 35 percent more traffic was handled with the 4D. Aircraft holding time in the 4D mode was only 30 percent of that required in the 3D mode. In addition, the orderliness of traffic was improved significantly in the 4D mode.

Tobias, L.; Obrien, P. J.

1977-01-01

303

Detrended Fluctuation Analysis and Adaptive Fractal Analysis of Stride Time Data in Parkinson's Disease: Stitching Together Short Gait Trials  

PubMed Central

Variability indicates motor control disturbances and is suitable to identify gait pathologies. It can be quantified by linear parameters (amplitude estimators) and more sophisticated nonlinear methods (structural information). Detrended Fluctuation Analysis (DFA) is one method to measure structural information, e.g., from stride time series. Recently, an improved method, Adaptive Fractal Analysis (AFA), has been proposed. This method has not been applied to gait data before. Fractal scaling methods (FS) require long stride-to-stride data to obtain valid results. However, in clinical studies, it is not usual to measure a large number of strides (e.g., strides). Amongst others, clinical gait analysis is limited due to short walkways, thus, FS seem to be inapplicable. The purpose of the present study was to evaluate FS under clinical conditions. Stride time data of five self-paced walking trials ( strides each) of subjects with PD and a healthy control group (CG) was measured. To generate longer time series, stride time sequences were stitched together. The coefficient of variation (CV), fractal scaling exponents (DFA) and (AFA) were calculated. Two surrogate tests were performed: A) the whole time series was randomly shuffled; B) the single trials were randomly shuffled separately and afterwards stitched together. CV did not discriminate between PD and CG. However, significant differences between PD and CG were found concerning and . Surrogate version B yielded a higher mean squared error and empirical quantiles than version A. Hence, we conclude that the stitching procedure creates an artificial structure resulting in an overestimation of true . The method of stitching together sections of gait seems to be appropriate in order to distinguish between PD and CG with FS. It provides an approach to integrate FS as standard in clinical gait analysis and to overcome limitations such as short walkways. PMID:24465708

Liebherr, Magnus; Haas, Christian T.

2014-01-01

304

Measuring the impact of temperature changes on the wine production in the Douro Region using the short time fourier transform  

NASA Astrophysics Data System (ADS)

This paper investigates the cyclical behaviour of the wine production in Douro region during the period 1932-2008. In general, wine production is characterised by large fluctuations which are composed of short-term and/or long-term cycles. The aim of this paper is twofold: firstly, we decompose the wine production's variance in order to find the dominating production cycles, i.e we try to explain whether wine production follows more long-term or short-term cycles. In the next step, we try to explain those cycles using a dependent variable, namely the medium spring temperature (Tm_Sp) for the period 1967-2008. We estimated a Time-Varying Autoregressive Model, which could explain 75% of the production that is characterised by 4.8- and 2.5-year cycles. We use the Short Time Fourier Transform to decompose the link between wine production and temperature. When the temperature was incorporated, the R 2 increased and the Akaike criterion value was lower. Hence, Tm_Sp causes a large amount of these cycles and the wine production variation reflects this relationship. In addition to an upward trend, there is a clearly identifiable cycle around the long-term trend in production. We also show how much of the production cycle and what cycle in particular is explained by the Tm_Sp. There is a stable but not constant link between production and the Tm_Sp. In particular, the temperature is responsible for 5.2- and 2.4-year cycles which has been happening since the 1980s. The Tm_Sp can also be used as an indicator for the 4.8- and 2.5-year cycles of production. The developed model suggests that stationarity is a questionable assumption, and this means that historical distributions of wine production are going to need dynamic updating.

Cunha, Mário; Richter, Christian

2012-03-01

305

Observation of Brownian motion in liquids at short times: instantaneous velocity and memory loss.  

PubMed

Measurement of the instantaneous velocity of Brownian motion of suspended particles in liquid probes the microscopic foundations of statistical mechanics in soft condensed matter. However, instantaneous velocity has eluded experimental observation for more than a century since Einstein's prediction of the small length and time scales involved. We report shot-noise-limited, high-bandwidth measurements of Brownian motion of micrometer-sized beads suspended in water and acetone by an optical tweezer. We observe the hydrodynamic instantaneous velocity of Brownian motion in a liquid, which follows a modified energy equipartition theorem that accounts for the kinetic energy of the fluid displaced by the moving bead. We also observe an anticorrelated thermal force, which is conventionally assumed to be uncorrelated. PMID:24675957

Kheifets, Simon; Simha, Akarsh; Melin, Kevin; Li, Tongcang; Raizen, Mark G

2014-03-28

306

Short-time distribution of particle displacements due to swimming microorganisms  

E-print Network

The experiments of Leptos et al. [Phys. Rev. Lett. 103,198103 (2009)] show that the displacements of small particles affected by swimming microorganisms achieve a non-Gaussian distribution, which nevertheless scales diffusively. We use a simple model where the particles undergo repeated 'kicks' due to the swimmers to explain the shape of the distribution as a function of the volume fraction of swimmers. The net displacement is determined by the self-convolution of the drift function caused by one swimmer, and by a Poisson distribution for the frequency of interactions. The only adjustable parameter is the strength of the stresslet term in our spherical squirmer model. The effective diffusivity predicted by the model is consistent with the experiments, with no further parameter adjustments. The diffusive scaling appears to be due to the particular form of the drift function, and is not statistical in origin. The model also suggests that the scaling disappears for longer times, when the swimmers undergo signifi...

Thiffeault, Jean-Luc

2014-01-01

307

Short-term forecasting of life-threatening cardiac arrhythmias based on symbolic dynamics and finite-time growth rates  

NASA Astrophysics Data System (ADS)

Ventricular tachycardia or fibrillation (VT-VF) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this study is to find early signs of sustained VT-VF in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they store the 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 17 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e., without a VT-VF event. To characterize these rather short data sets, we calculate heart rate variability parameters from the time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that neither the time nor the frequency domain parameters show significant differences between the VT-VF and the control time series. However, two parameters from symbolic dynamics as well as the finite-time growth rates discriminate significantly both groups. These findings could be of importance in algorithms for next generation ICD's to improve the diagnostics and therapy of VT-VF.

Wessel, Niels; Ziehmann, Christine; Kurths, Jürgen; Meyerfeldt, Udo; Schirdewan, Alexander; Voss, Andreas

2000-01-01

308

Time-Resolved X-Ray Brightness Measurements from Short-Pulse, Laser-Irradiated Thin Foils  

NASA Astrophysics Data System (ADS)

The production of soft x rays (˜keV) from high-intensity, short-pulse laser plasmas is important for future applications such as backlighting cryogenic targets on OMEGA. The physics of short-pulse laser--plasma interactions and the coupling of laser energy into both the thermal plasma and fast electrons were studied to optimize x-ray production from mass-limited aluminum foil targets. Foil targets of various sizes from 50 to 500 ?m were irradiated with picosecond pulse duration laser pulses at intensities similar to OMEGA area backlighter schemes (10^18 to >10^19 W/cm^2). The time-resolved x-ray emission was measured with a conically curved crystal coupled with an ultrafast x-ray streak camera. The He? and the Ly? line emission from aluminum foils was spectrally measured and temporally resolved. In addition, the x-ray source was characterized with a calibrated time-integrated spectrograph and spatially resolved images were taken with a spherically curved Bragg crystal. The combination of these measurements allows the brilliance of the x-ray line source to be inferred. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

Eichman, B.; Theobald, W.; Stoeckl, C.; Mileham, C.; Sangster, T. C.

2012-10-01

309

Short-time distribution of particle displacements due to swimming microorganisms  

E-print Network

The experiments of Leptos et al. [Phys. Rev. Lett. 103,198103 (2009)] show that the displacements of small particles affected by swimming microorganisms achieve a non-Gaussian distribution, which nevertheless scales diffusively. We use a simple model where the particles undergo repeated 'kicks' due to the swimmers to explain the shape of the distribution as a function of the volume fraction of swimmers. The net displacement is determined by the self-convolution of the drift function caused by one swimmer, and by a Poisson distribution for the frequency of interactions. The only adjustable parameter is the strength of the stresslet term in our spherical squirmer model. The effective diffusivity predicted by the model is consistent with the experiments, with no further parameter adjustments. The diffusive scaling appears to be due to the particular form of the drift function, and is not statistical in origin. The model also suggests that the scaling disappears for longer times, when the swimmers undergo significant reorientation.

Jean-Luc Thiffeault

2014-08-20

310

Radiolytic Cryovolcanism Revisited  

NASA Astrophysics Data System (ADS)

Active geysers of water vapor and ice grains from the south pole of Enceladus are not yet definitively explained in terms of energy sources and processes. Other instances of hot (Io) and cold (Mars, Triton) volcanism beyond Earth are known if not fully understood. We revisit, in comparison to other models, the 'Old Faithful' theory of radiolytic gas-driven cryovolcanism first proposed by Cooper et al. [Plan. Sp. Sci. 2009]. In the energetic electron irradiation environment of Enceladus within Saturn's magnetosphere, a 10-percent duty cycle could be maintained for current geyser activity driven by gases from oxidation of ammonia to N2 and methane to CO2 in the thermal margins of a south polar sea. Much shorter duty cycles down to 0.01 percent would be required to account for thermal power output up to 16 GW, Steady accumulation of oxidant energy over four billion years could have powered all Enceladus emissions over the past four hundred thousand to four hundred million years. There could be separate energy sources driving mass flow and thermal emission over vastly different time scales. Since episodic tidal dissipation on 10 Myr time scales at 0.1 - 1 Gyr intervals [O'Neill and Nimmo, Nature 2010], and thus duty cycles 1 - 10 percent, could heat the polar sea to the current level, the radiolytic energy source could easily power and modulate the geyser mass flow on million-year time scales. Maximum thermal emission temperature 223 K [Abramov and Spencer, Icarus 2009] hints at thermal buffering in the basal and vent wall layers by a 1:1 H2O:H2O2 radiolytic eutectic, assuming deep ice crust saturation with H2O2 from long cumulative surface irradiation and downward ice convection. Due to density stratification the peroxide eutectic and salt water layers could separate, so that the denser peroxide layer (1.2 g/cc) descends to the polar sea while the lighter salt water (1.05 g/cc) rises along separate channels. Methane reservoirs could be found dissolved into the polar sea, or else trapped in hydrates [Kieffer et al., Science 2006] along flow paths and at the walls of the polar sea at surface depths below 20 km [Fortes, Icarus 2007]. Driver gas production for cryovolcanism could occur wherever these two layers come into contact under requisite temperature and pressure conditions, e.g. from 220 K and 10 bar at the 10-km basal layer of the overlying ice crust to 647 K and 220 bars at the liquid water limit, above the core-mantle boundary at 460 bars [Fortes, Icarus 2007]. We expect H2O2 oxidation to ignite at high temperatures but metallic minerals could catalyze reactions at lower temperatures nearer the basal layer. Pressure effects on oxidation rates are uncertain. Definitive modeling of Enceladus cryovolcanism likely involves synthesis of key processes from multiple models: Cold Faithful [Porco et al., Science 2006], Frigid Faithful [Keiffer et al., Science 2006], Frothy Faithful [Fortes, Icarus 2007], Old Faithful, and 'Perrier Ocean' recirculation [Matson et al., Icarus 2012].

Cooper, J. F.; Cooper, P. D.; Sittler, E. C.; Wesenberg, R. P.

2013-12-01

311

IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 23, NO. 20, OCTOBER 15, 2011 1439 All-Optical Short-Time Fourier Transform Based  

E-print Network

-Time Fourier Transform Based on a Temporal Pulse-Shaping System Incorporating an Array of Cascaded Linearly-optical approach to implementing short-time Fourier transform (STFT) of a high-speed and broadband elec- trical time, as a dispersive element to implement real-time Fourier transform. A theoretical analysis

Yao, Jianping

312

Duty periods with early start times restrict the amount of sleep obtained by short-haul airline pilots.  

PubMed

Most of the research related to human fatigue in the aviation industry has focussed on long-haul pilots, but short-haul pilots also experience elevated levels of fatigue. The aim of this study was to examine the impact of early start times on the amount of sleep obtained prior to duty and on fatigue levels at the start of duty. Seventy short-haul pilots collected data regarding their duty schedule and sleep/wake behaviour for at least two weeks. Data were collected using self-report duty/sleep diaries and wrist activity monitors. Mixed-effects regression analyses were used to examine the effects of duty start time (04:00-10:00 h) on (i) the total amount of sleep obtained in the 12h prior to the start of duty and (ii) self-rated fatigue level at the start of duty. Both analyses indicated significant main effects of duty start time. In particular, the amount of sleep obtained in the 12h prior to duty was lowest for duty periods that commenced between 04:00 and 05:00 h (i.e. 5.4h), and greatest for duty periods that commenced between 09:00 and 10:00 h (i.e. 6.6h). These data indicate that approximately 15 min of sleep is lost for every hour that the start of duty is advanced prior to 09:00 h. In addition, self-rated fatigue at the start of duty was highest for duty periods that commenced between 04:00 and 05:00 h, and lowest for duty periods that commenced between 09:00 and 10:00 h. Airlines should implement a fatigue risk management system (FRMS) for short-haul pilots required to work early-morning shifts. One component of the FRMS should be focussed on the production of 'fatigue-friendly' rosters. A second component of the FRMS should be focussed on training pilots to optimise sleep opportunities, to identify circumstances where the likelihood of fatigue is elevated, and to manage the risks associated with fatigue-related impairment. PMID:22239926

Roach, Gregory D; Sargent, Charli; Darwent, David; Dawson, Drew

2012-03-01

313

Effects of lateral velocity heterogeneity under the Nevada Test Site on short-period P wave amplitudes and travel times  

NASA Astrophysics Data System (ADS)

Short-period teleseismic P waves from the Nevada Test Site (NTS) show systematic variations in amplitudes and travel times, with low amplitudes corresponding to fast travel times, suggesting elastic focussing-defocussing effects. Also, the azimuthal amplitude and travel time patterns for events at the Pahute Mesa subsite are systematically different from those at the Yucca Flat subsite, indicating the presence of a near-source component in both the amplitude and travel-time variations. This component is isolated by removing the mean station pattern for all of NTS from the observations. A very-near-source component in the Pahute Mesa observations is also isolated by removing subsite station means from the measurements, whereas the Yucca Flat observations exhibited no coherent very-near-source component. These anomalies are back-projected through laterally homogeneous structure to form thin lens models at various depths. Travel-time delays are predicted from the amplitude variations using the equation for wavefront curvature. The long-wavelength components of the predicted and observed time delays correlate well, at depths of 25 km for the very-near-source component under Pahute Mesa and 160 km for the regional component under NTS. The time delay surfaces predicted by the amplitudes at these depths are mapped into warped velocity discontinuities suitable for the calculation of synthetic seismograms using the Kirchhoff-Helmholtz integral formulation. Both the intersite (near-source) and intrasite (very-near-source) differences in amplitudes are qualitatively predicted very well, although the range of variation is somewhat underpredicted. This deficiency is likely due to the destructive interference of anomalies inherent in back-projection to a single layer.

Lynnes, Christopher S.; Lay, Thorne

1990-03-01

314

Relaxation and short time dynamics of bulk liquids and fluids confined in spherical cavities and slit pores.  

PubMed

The density of states for bulk and confined fluids have been modeled using a recently proposed gamma distribution (Krishnan, S. H.; Ayappa, K. G. J. Chem. Phys. 2004, 121, 3197). The gamma distribution results in a closed form analytical expression for the velocity autocorrelation function and the relaxation time of the fluid. The two parameters of the gamma distribution are related analytically to the second and fourth frequency moments of the fluid using short time expansions. The predictions by the proposed gamma model are compared with the velocity autocorrelation functions obtained using the theory of instantaneous normal modes (INMs) and from molecular dynamics simulations. The model is applied to a bulk soft sphere liquid and fluids confined in a spherical cavity and slit-shaped pores. The gamma model is able to capture the resulting changes in relaxation time due to changes in density and temperature extremely well for both the bulk liquid and confined inhomogeneous fluid situations. In all cases, the predictions by the gamma model are superior to those obtained from the INM theory. In the case of the fluid confined in a slit pore, the loadings were obtained from a grand canonical Monte Carlo simulation where the pore is equilibrated with a bulk fluid. This is similar to a confinement situation in a surface force apparatus. The predicted relaxation times vs pore widths from the gamma model are seen to accurately capture the oscillations due to formation and disruption of layers within the slit pore. PMID:16375288

Krishnan, S H; Ayappa, K G

2005-12-15

315

The angular momentum of baryons and dark matter halos revisited  

Microsoft Academic Search

Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive mesh refinement, we find that at the time of accretion, gas and dark matter do carry a similar amount of specific

Taysun Kimm; Julien Devriendt; Adrianne Slyz; Christophe Pichon; Susan A. Kassin; Yohan Dubois

2011-01-01

316

A Distributed Web-based Solution for Ionospheric Model Real-time Management, Monitoring, and Short-term Prediction  

NASA Astrophysics Data System (ADS)

With the widespread availability of the Internet today, many people can monitor various scientific research activities. It is important to accommodate this interest providing on-line access to dynamic and illustrative Web-resources, which could demonstrate different aspects of ongoing research. It is especially important to explain and these research activities for high school and undergraduate students, thereby providing more information for making decisions concerning their future studies. Such Web resources are also important to clarify scientific research for the general public, in order to achieve better awareness of research progress in various fields. Particularly rewarding is dissemination of information about ongoing projects within Universities and research centers to their local communities. The benefits of this type of scientific outreach are mutual, since development of Web-based automatic systems is prerequisite for many research projects targeting real-time monitoring and/or modeling of natural conditions. Continuous operation of such systems provide ongoing research opportunities for the statistically massive validation of the models, as well. We have developed a Web-based system to run the University of Alaska Fairbanks Polar Ionospheric Model in real-time. This model makes use of networking and computational resources at the Arctic Region Supercomputing Center. This system was designed to be portable among various operating systems and computational resources. Its components can be installed across different computers, separating Web servers and computational engines. The core of the system is a Real-Time Management module (RMM) written Python, which facilitates interactions of remote input data transfers, the ionospheric model runs, MySQL database filling, and PHP scripts for the Web-page preparations. The RMM downloads current geophysical inputs as soon as they become available at different on-line depositories. This information is processed to provide inputs for the next ionospheic model time step and then stored in a MySQL database as the first part of the time-specific record. The RMM then performs synchronization of the input times with the current model time, prepares a decision on initialization for the next model time step, and monitors its execution. Then, as soon as the model completes computations for the next time step, RMM visualizes the current model output into various short-term (about 1-2 hours) forecasting products and compares prior results with available ionospheric measurements. The RMM places prepared images into the MySQL database, which can be located on a different computer node, and then proceeds to the next time interval continuing the time-loop. The upper-level interface of this real-time system is the a PHP-based Web site (http://www.arsc.edu/SpaceWeather/new). This site provides general information about the Earth polar and adjacent mid-latitude ionosphere, allows for monitoring of the current developments and short-term forecasts, and facilitates access to the comparisons archive stored in the database.

Kulchitsky, A.; Maurits, S.; Watkins, B.

2006-12-01

317

Alteration in scaling behavior of short-term heartbeat time series for professional shooting athletes from rest to exercise  

NASA Astrophysics Data System (ADS)

Scaling analysis of heartbeat time series has emerged as a useful tool for assessing the autonomic cardiac control under various physiologic and pathologic conditions. We study the heartbeat activity and scaling behavior of heartbeat fluctuations regulated by autonomic nervous system for professional shooting athletes under two states: rest and exercise, by applying the detrended fluctuation analysis method. We focus on alteration in correlation properties of heartbeat intervals for the shooters from rest to exercise, which may have a potential value in monitoring the quality of training and evaluating the sports capacity of the athletes. The result shows that scaling exponents of short-term heart rate variability signals from the shooters get significantly larger during exercise compared with those obtained at rest. It demonstrates that during exercise stronger correlations appear in the heartbeat series of shooting athletes in order to satisfy the specific requirements for high concentration and better control on their heart beats.

Zhuang, Jian Jun; Ning, Xin Bao; He, Ai Jun; Zou, Ming; Sun, Biao; Wu, Xu Hui

2008-11-01

318

Implementing high-temperature short-time media treatment in commercial-scale cell culture manufacturing processes.  

PubMed

The production of therapeutic proteins by mammalian cell culture is complex and sets high requirements for process, facility, and equipment design, as well as rigorous regulatory and quality standards. One particular point of concern and significant risk to supply chain is the susceptibility to contamination such as bacteria, fungi, mycoplasma, and viruses. Several technologies have been developed to create barriers for these agents to enter the process, e.g. filtration, UV inactivation, and temperature inactivation. However, if not implemented during development of the manufacturing process, these types of process changes can have significant impact on process performance if not managed appropriately. This article describes the implementation of the high-temperature short-time (HTST) treatment of cell culture media as an additional safety barrier against adventitious agents during the transfer of a large-scale commercial cell culture manufacturing process. The necessary steps and experiments, as well as subsequent results during qualification runs and routine manufacturing, are shown. PMID:24362912

Pohlscheidt, Michael; Charaniya, Salim; Kulenovic, Fikret; Corrales, Mahalia; Shiratori, Masaru; Bourret, Justin; Meier, Steven; Fallon, Eric; Kiss, Robert

2014-04-01

319

An Evaluation of Some Current Practices for Short-Time Elevated-Temperature Tensile Tests of Metals  

NASA Technical Reports Server (NTRS)

The effect of different testing practices on the short-time elevated-temperature tensile properties was determined for 2024-T3 aluminum-alloy, HM21A-T8 and HK31A-H24 magnesium-alloy, and 12 MoV stainless-steel sheet. Tests were made under single strain-rate and single head-speed conditions. A dual strain-rate test was also included. An evaluation of the effects of these practices is given for the tensile and yield strengths, the elongation in 2 inches, and the uniform elongation. The need for a uniform testing practice is demonstrated. Recommended practices suggested by different organizations are included.

Manning, Charles R., Jr.; Heimerl, George J.

1960-01-01

320

Short-Term Chromospheric Variability in alpha Tauri (K5 III): Results from IUE Time Series Observations  

NASA Technical Reports Server (NTRS)

We evaluate time series observations of chromospheric lines (Mg II, Mg I, and C II) for the K giant alpha Tau obtained using the IUE LWP camera at high dispersion. These observations cover a time span of about 2 weeks in 1994 February-March and were designed to resolve variations occurring within hours, days, and weeks. We consider the observational results in relation to theoretical acoustic heating models, motivated by the fact that alpha Tau may exhibit a basal (i.e., minimum) level of chromospheric activity. The data reveal flux variations between the extremes of 8% in Mg II h+k and 15% in each emission component. These variations occur on timescales as short as 8 hr but not on timescales longer than approx.3 days. For the h and k components, flux variations occurring on a timescale as short as 1.5 hr are also found. These changes are often not correlated (and are sometimes even anticorrelated), leading to remarkable differences in the h/k ratios. We argue that these results are consistent with the presence of strong acoustic shocks, which can lead to variable Mg II line emission when only a small number of strong shocks are propagating through the atmosphere. We deduce the electron density in the C II lambda 2325 line formation region to be log(base e) of N. approx. equals 9.0, in agreement with previous studies. Our data provide evidence that the Mg II basal flux limit for K giants might be a factor of 4 higher than suggested by Rutten et al.

Cuntz, Manfred; Deeney, Bryan D.; Brown, Alexander; Stencel, Robert E.

1996-01-01

321

FROST: Revisited and Distributed Vincent Poirriez  

E-print Network

FROST: Revisited and Distributed Vincent Poirriez LAMIH UVHC,UMR CNRS 8530 59313 Valenciennes de la Recherche FROST: Revisited and Distributed Vincent Poirriez HICOMB'05:April 04, 2005 #12;Protein Threading Problem Associate a protein sequence to an already known 3D structure. FROST: Revisited

Singer, Daniel

322

Longitudinal Assessment of Optical Quality and Intraocular Scattering Using the Double-Pass Instrument in Normal Eyes and Eyes with Short Tear Breakup Time  

PubMed Central

Purpose To assess the longitudinal changes in optical quality including intraocular scattering in normal eyes and eyes with short tear breakup time (TBUT). Methods We prospectively examined twenty eyes of 20 healthy subjects, and age-matched twenty eyes of 20 short TBUT subjects. The modulation transfer function (MTF) cutoff frequency, the Strehl ratio, and the objective scattering index (OSI) were quantitatively assessed using an Optical Quality Analysis System. We investigated the changes in these variables measured consecutively at the initial examination, 5, and 10 seconds without blinking. We also compared these variables in eyes with short TBUT with those in normal eyes. Results No significant differences in the MTF cutoff frequency, Strehl ratio, or OSI were detected over a 10-second period in normal eyes. These variables also became significantly degraded even over a 5-second period in eyes with short TBUT (p<0.01). We found significant differences in these variables at 5 and 10 seconds (p<0.05), but none immediately after the blink between normal and short TBUT eyes. Conclusions Optical quality including intraocular scattering deteriorated significantly with time in eyes with short TBUT, whereas we found significant differences over a 10-second period in normal eyes. Eyes with short TBUT showed greater deterioration in optical quality after the blink than normal eyes. The longitudinal assessment of optical quality may be effective in distinguishing eyes with short TBUT from normal eyes. PMID:24324787

Kobashi, Hidenaga; Kamiya, Kazutaka; Yanome, Kyohei; Igarashi, Akihito; Shimizu, Kimiya

2013-01-01

323

Electrocardiogram Signal and Linear Time-Frequency Transforms  

NASA Astrophysics Data System (ADS)

The diagnostic analysis of non-stationary multi component signals such as electrocardiogram (ECG) involves the use of time-frequency transforms. So, the application of time-frequency transforms to an ECG signal is an important problem of research. In this paper, initially, linear transforms like short time Fourier transform, continuous wavelet transforms, s-transform etc. are revisited. Then the application of these transforms to normal and abnormal ECG signals is illustrated. It has been observed that s-transform provides better time and frequency resolution compared to other linear transforms. The fractional Fourier transform provides rotation to the spectrogram representation.

Krishna, B. T.

2014-06-01

324

Functional traits as indicators of fodder provision over a short time scale in species-rich grasslands  

PubMed Central

Background and Aims Fodder provision in species-rich grasslands, i.e. herbage growth, proportion of leaf, and leaf and stem digestibility, is difficult to predict for short periods of time, such as between two defoliations or less. The value of two methods based on plant traits for evaluating these agronomic properties was examined. Methods One method is based on plant trait measurements on the plant community (leaf dry matter content, plant height, flowering date); the other is on vegetation composition expressed as plant functional types (acquisitive versus conservative PFTs) established by measuring leaf dry matter content on pure grass stands. The experiment consisted of 18 fields with three different defoliation regimes (combinations of cutting and grazing) and two levels of fertilization. To establish a growth curve over the first growth cycle, herbage was sampled about 10 times in spring. Key Results Coefficients of correlation between agronomic properties of the vegetation and its functional composition were higher when the latter was assessed through PFT and an indicator of the plant nutrient status (Ni) instead of measured plant traits. The date at which the ceiling yield occurred for the standing herbage mass or only the leaf component, which varied by up to 500 degree-days between treatments, and the leaf proportion, depended entirely on the PFT, and largely so for the leaf digestibility. The standing herbage mass at the time of ceiling yield depended only on Ni, or mainly so in the case of the daily herbage growth rate. Similar plant digestibility between plant communities was found at flowering time, although there were big differences in PFT composition. The shape of the growth curve was flatter when there was great functional diversity in the plant community. Conclusions The PFT composition and the Ni were more reliable than the plant functional traits measured in the field for evaluating herbage growth pattern and digestibility in spring. PMID:18974100

Ansquer, Pauline; Duru, Michel; Theau, Jean Pierre; Cruz, Pablo

2009-01-01

325

Short residence times for alkaline Vesuvius magmas in a multi-depth supply system: Evidence from geochemical and textural studies  

NASA Astrophysics Data System (ADS)

It is crucial to understand magma chamber chemico-physical conditions and residence times for high-risk volcanoes because these factors control the occurrence and size of future eruptions. In order to define magmatic pressure-temperature conditions and residence times at the Somma-Vesuvius volcano, we studied the geochemistry and texture of selected past eruptions that are representative of the entire volcanic history. Our petrological model indicates a multi-depth magma chamber composed of a deeper tephritic (350-400 Mpa) magma layer, which fed Strombolian and effusive eruptions during open-conduit activity, and an upper (200-250 Mpa) phonolitic level, which supplied the high explosive events that followed closed-conduit repose time. This upper reservoir matches the inferred transition between sedimentary sequences and metamorphic basement. At this level, the presence of a structural and lithological discontinuity favors magma storage during closed-conduit periods. The prevalent differentiation process was fractional crystallization during the magma cooling associated with upward migration of less dense, evolved liquids. Our results indicate that major steam exolution occurred during the late crystallization stage of phonolites, which accounts for the high Volcanic Explosivity Index (VEI) of eruptions supplied by these melts. Moreover, our phenocryst CSD data reveal the rapid crystallization and differentiation (decades to centuries) of alkaline Somma-Vesuvius magmas. This implies that the 400 km 2 partial melting zone detected by tomography studies at 8-10 km depth beneath Vesuvius should consist of differentiated magma that is already capable of generating a large-scale (plinian) explosive event if renewed activity develops out of the present closed-conduit state. Additionally, because our microlite CSD data indicate rapid magma migration from the chamber toward the surface, precursory activity could appear only short time before a major eruption.

Pappalardo, Lucia; Mastrolorenzo, Giuseppe

2010-07-01

326

A Bayesian method for characterizing distributed micro-releases: II. inference under model uncertainty with short time-series data.  

SciTech Connect

Terrorist attacks using an aerosolized pathogen preparation have gained credibility as a national security concern after the anthrax attacks of 2001. The ability to characterize such attacks, i.e., to estimate the number of people infected, the time of infection, and the average dose received, is important when planning a medical response. We address this question of characterization by formulating a Bayesian inverse problem predicated on a short time-series of diagnosed patients exhibiting symptoms. To be of relevance to response planning, we limit ourselves to 3-5 days of data. In tests performed with anthrax as the pathogen, we find that these data are usually sufficient, especially if the model of the outbreak used in the inverse problem is an accurate one. In some cases the scarcity of data may initially support outbreak characterizations at odds with the true one, but with sufficient data the correct inferences are recovered; in other words, the inverse problem posed and its solution methodology are consistent. We also explore the effect of model error-situations for which the model used in the inverse problem is only a partially accurate representation of the outbreak; here, the model predictions and the observations differ by more than a random noise. We find that while there is a consistent discrepancy between the inferred and the true characterizations, they are also close enough to be of relevance when planning a response.

Marzouk, Youssef; Fast P. (Lawrence Livermore National Laboratory, Livermore, CA); Kraus, M. (Peterson AFB, CO); Ray, J. P.

2006-01-01

327

Nucleoside uptake in macrophages from various murine strains: a short-time and a two-step stimulation model  

SciTech Connect

Kinetics of (3H)-uridine uptake by murine peritoneal macrophages (pM phi) is early altered after exposure to a variety of stimuli. Alterations caused by Candida albicans, lipopolysaccharide (LPS) and recombinant interferon-gamma (rIFN-gamma) were similar in SAVO, C57BL/6, C3H/HeN and C3H/HeJ mice, and were not correlated with an activation process as shown by the amount of tumor necrosis factor-alpha (TNF-alpha) being released. Short-time exposure to all stimuli resulted in an increased nucleoside uptake by SAVO pM phi, suggesting that the tumoricidal function of this cell either depends from the type of stimulus or the time when the specific interaction with the cell receptor is taking place. Experiments with priming and triggering signals confirmed the above findings, indicating that the increase or the decrease of nucleoside uptake into the cell depends essentially on the chemical nature of the priming stimulus. The triggering stimulus, on the other hand, is only able to amplify the primary response.

Busolo, F.; Conventi, L.; Grigolon, M.; Palu, G. (Inst. of Microbiology of Padua Univ. (Italy))

1991-06-28

328

Shorting time of magnetically insulated reflex-ion diodes from the neutral-atom charge-exchange mechanism  

SciTech Connect

In a magnetically insulated diode, collision-free electrons return to the cathode and no electron current is present at the anode. Electron transport to the anode is studied in this paper. Steady-state space-charge-limited flow is assumed initially. Breakdown of ion flow occurs when static neutral atoms at the anode undergo charge exchange, which results in neutral atoms drifting across the diode. These are subsequently ionized by reflexing ions producing electrons trapped in Larmor orbits throughout the diode. These electrons drift to the anode via ionization and inelastic collisions with other neutral atoms. Model calculations compare the effects of foil and mesh cathodes. Steady-state space-charge-limited ion current densities are calculated. The neutral atom density at the cathode is determined as a function of time. The shorting time of the diode is scaled versus the electrode separation d, the diode potential V/sub 0/, the magnetic field, and the initial concentration of static neutron atoms.

Strobel, G.

1981-10-01

329

The sun compass revisited  

PubMed Central

Many animals, and birds in particular, are thought to use directional information from the sun in the form of a time-compensated sun compass, with predictably deviated orientation under clock shift being regarded as the litmus test of this. We suggest that this paradigm obscures a number of other ways in which solar-derived information could be important in animal orientation. We distinguish between the known use of the sun's azimuth to provide absolute geographical direction (compass mechanism) and its possible use to detect changes in heading (heading indicator mechanism). Just as in an aircraft, these two kinds of information may be provided by separate mechanisms and used for different functions, for example for navigation versus steering. We also argue that although a solar compass must be time-referenced to account for the sun's apparent diurnal movement, this need not entail full time compensation. This is because animals might also use time-dependent solar information in an associatively acquired, and hence time-limited, way. Furthermore, we show that a solar heading indicator, when used on a sufficiently short timescale, need not require time compensation at all. Finally, we suggest that solar-derived cues, such as shadows, could also be involved in navigation in ways that depend explicitly upon position, and are therefore not strictly compass-related. This could include giving directionality to landmarks, or acting as time-dependent landmarks involved in place recognition. We conclude that clock shift experiments alone are neither necessary nor sufficient to identify the occurrence of all conceivable uses of solar information in animal orientation, so that a predictable response to clock shift should not be regarded as an acid test of the use of solar information in navigation. PMID:25389374

Guilford, Tim; Taylor, Graham K.

2014-01-01

330

Personality-relationship transactions revisited.  

PubMed

The transactional paradigm states that people create, maintain, and change their environments according to their personalities. At the same time, the environment reacts back on personality. As social relationships are part of an individual's environment, this likewise implies that there are reciprocal transactions between personality and relationships. However, earlier studies have concluded that adult personality traits are so stable that they have a stronger effect on later relationships, but that relationship effects on personality are negligible. In this article, we contend that personality-relationship transactions should be revisited. We submit that the relative powers of personality versus relationship effects depend on the type of life transition during which the effects take place: Relationship effects on personality development are more likely to emerge in the context of rather normative and highly scripted life transitions, whereas personality effects on relationship development are more likely to occur in the context of rather non-normative life transitions that are less regulated by social expectations. We illustrate these assumptions with examples from our own work and other findings reported in the literature. Furthermore, we theorize that effects of personality-relationship transactions on health also vary with the normativeness of the eliciting life transition. PMID:23927445

Neyer, Franz J; Mund, Marcus; Zimmermann, Julia; Wrzus, Cornelia

2014-12-01

331

Pharmacy School Survey Standards Revisited  

PubMed Central

In a series of 3 papers on survey practices published from 2008 to 2009, the editors of the American Journal of Pharmaceutical Education presented guidelines for reporting survey research, and these criteria are reflected in the Author Instructions provided on the Journal’s Web site. This paper discusses the relevance of these criteria for publication of survey research regarding pharmacy colleges and schools. In addition, observations are offered about surveying of small "universes" like that comprised of US colleges and schools of pharmacy. The reason for revisiting this issue is the authors’ concern that, despite the best of intentions, overly constraining publication standards might discourage research on US colleges and schools of pharmacy at a time when the interest in the growth of colleges and schools, curricular content, clinical education, competence at graduation, and other areas is historically high. In the best traditions of academia, the authors share these observations with the community of pharmacy educators in the hope that the publication standards for survey research about US pharmacy schools will encourage investigators to collect and disseminate valuable information. PMID:23459404

Barnett, Mitchell J.; Lenth, Russell V.; Knapp, Katherine K.

2013-01-01

332

Development of the short time exposure (STE) test: an in vitro eye irritation test using SIRC cells.  

PubMed

Using SIRC (rabbit corneal cell line) cells, we developed an alternative eye irritation test: the short time exposure (STE) test. This STE test is a cytotoxicity test using physiological saline or mineral oil as the test solvent. Evaluation exposure time is short (5 min), which is similar to actual exposure situations, and uses the cell viability (CV) at a constant concentration as the endpoint for irritation potential. First, in order to confirm the usefulness of this STE test in assessing eye irritation potential of chemicals, 51 raw materials were tested and the correlation between CV in the STE test and the eye irritation score in the Draize test was examined. For the undiluted raw materials tested in the Draize test, the 5% test concentration in the STE test gave irritation classes that correlated well with the irritation classes from the Draize test (accuracy: 89.6%). For those materials tested as a 10% solution in the Draize test, STE irritation classes with 0.05% test concentration corresponded well with the Draize irritation classes (accuracy: 80.0%). Next, using the cell viabilities at these two concentrations, the STE prediction model (PM) was developed. A score of 1 or 2 was given for the results from each tested concentration in the STE test and Draize test. The scores from each test were then summed to yield a 3-level (Rank 1: minimally irritant, Rank 2: moderate irritant, Rank 3: severe irritant) eye irritation potential classification. Rank classification in the STE test showed a good correlation mostly to that in the Draize test (irritation class correspondence rate: 70.2%, but after exclusion of data of alcoholic materials, the rate was 91.7%). In most cytotoxicity test, the cytotoxicity of acids and amines is generally underestimated due the use of medium as the solvent. This is the result of the buffering capacity of the media. On the other hand, the STE test could predict the eye irritation potential by evaluating the chemical with a 5% test concentration. Eleven water insoluble materials such as toluene, octanol, and hexanol could be evaluated by using mineral oil as test solvent in the STE test. The STE test demonstrated itself to be simple, promising, have great potential, be of value, and to be an easily standardized alternative eye irritation test. PMID:18248950

Takahashi, Yutaka; Koike, Mirei; Honda, Hiroshi; Ito, Yuichi; Sakaguchi, Hitoshi; Suzuki, Hiroyuki; Nishiyama, Naohiro

2008-04-01

333

Unplanned Emergency Department Revisits within 72 Hours to a Secondary Teaching Referral Hospital in Taiwan  

Microsoft Academic Search

Background: When patients return to the emergency department (ED) shortly after being seen, it is generally assumed that their initial evaluation or treatment was inadequate. Objectives: The purpose of this study was to determine the rates and causes of revisits to the ED of a 710-bed secondary teaching referral hospital (Kuang Tien General Hospital), to identify areas for improvement, and

Chiu-Lung Wu; Fa-Tsai Wang; Yao-Chiu Chiang; Yuan-Fa Chiu; Teong-Giap Lin; Lian-Fong Fu; Tsung-Lung Tsai

2010-01-01

334

Revisiting Evidence for Modularity and Functional Equivalence across Verbal and Spatial Domains in Memory  

ERIC Educational Resources Information Center

The authors revisited evidence in favor of modularity and of functional equivalence between the processing of verbal and spatial information in short-term memory. This was done by investigating the patterns of intrusions, omissions, transpositions, and fill-ins in verbal and spatial serial recall and order reconstruction tasks under control,…

Guerard, Katherine; Tremblay, Sebastien

2008-01-01

335

Catheter ablation of canine ventricular myocardium. The use of repetitive short time constant capacitive shocks to increase lesion volume.  

PubMed

Arching and barotrauma, seen with high energy DC catheter ablation, are responsible for diffuse cardiac damage and coronary sinus rupture. In six anesthetized dogs, we investigated the effects of an increasing number of short time-constant capacitive shocks on the volume of myocardial damage. Each dog received capacitive shocks of 2 J/kg at 3 sites in the left ventricle. One shock was delivered in 2 dogs, 2 shocks were delivered in 2 dogs and 3 shocks were delivered in 2 dogs. Shock delivery was not accompanied by hemodynamic collapse, sustained ventricular tachycardia or ventricular fibrillation. The dogs were sacrificed at 60 minutes. Mean (SEM) lesion volumes were 195 (39) mm3, 480 (41) mm3, and 595 (110) mm3, respectively. Despite variability in individual volume of damage, there was a significant increase in lesion volume with an increasing number of shocks. There was no evidence of perforation or tamponade. Increasing myocardial damage can be produced using repetitive capacitive shocks. Delivery of 2 shocks produces clinically useful lesions without the adverse effects associated with single high energy shocks. Repetitive capacitive shocks offer a method of increasing lesion volume without increasing energy and thereby without compromising safety. PMID:9186286

Watanabe, I; Nakai, T; Yanagawa, S; Watanabe, H; Kojima, T; Kondo, K; Takahashi, Y; Saito, S; Ozawa, Y; Kanmatsuse, K

1997-01-01

336

Short time-scale AGN X-ray variability with EXOSAT: black hole mass and normalized variability amplitude  

NASA Astrophysics Data System (ADS)

The old EXOSAT medium energy measurements of high-frequency (HF) active galactic nuclei (AGN) power spectral normalization are re-examined in the light of accurate black hole mass determinations which were not available when these data were first published by Green et al. It is found that the normalized variability amplitude (NVA), measured directly from the power spectrum, is proportional to M?, where ? ˜ -0.54 ± 0.08. As NVA is the square root of the power, these observations show that the normalization of the HF power spectrum for this sample of AGN varies very close to inversely with black hole mass. Almost the same value of ? is obtained whether the quasar 3C 273 is included in the sample or not, suggesting that the same process that drives X-ray variability in Seyfert galaxies applies also to 3C 273. These observations support the work of Gierli?ski et al. who show that an almost exactly linear anticorrelation is required if the normalizations of the HF power spectra of AGN and X-ray binary systems are to scale similarly. These observations are also consistent with a number of studies showing that the short time-scale variance of AGN X-ray light curves varies approximately inversely with mass.

McHardy, I. M.

2013-03-01

337

Real-Time Imaging of DNA Damage in Yeast Cells Using Ultra-Short Near-Infrared Pulsed Laser Irradiation  

PubMed Central

Analysis of accumulation of repair and checkpoint proteins at repair sites in yeast nuclei has conventionally used chemical agents, ionizing radiation or induction of endonucleases to inflict localized damage. In addition to these methods, similar studies in mammalian cells have used laser irradiation, which has the advantage that damage is inflicted at a specific nuclear region and at a precise time, and this allows accurate kinetic analysis of protein accumulation at DNA damage sites. We show here that it is feasible to use short pulses of near-infrared laser irradiation to inflict DNA damage in subnuclear regions of yeast nuclei by multiphoton absorption. In conjunction with use of fluorescently-tagged proteins, this allows quantitative analysis of protein accumulation at damage sites within seconds of damage induction. PCNA accumulated at damage sites rapidly, such that maximum accumulation was seen approximately 50 s after damage, then levels declined linearly over 200–1000 s after irradiation. RPA accumulated with slower kinetics such that hardly any accumulation was detected within 60 s of irradiation, and levels subsequently increased linearly over the next 900 s, after which levels were approximately constant (up to ca. 2700 s) at the damage site. This approach complements existing methodologies to allow analysis of key damage sensors and chromatin modification changes occurring within seconds of damage inception. PMID:25409521

Guarino, Estrella; Cojoc, Gheorghe; García-Ulloa, Alfonso; Toli?, Iva M.; Kearsey, Stephen E.

2014-01-01

338

Intrinsic magnetic properties of BixCo2-xMnO4 spinels obtained by short-time etching  

NASA Astrophysics Data System (ADS)

We report the structural and magnetic properties of Co2MnO4, partially substituted by Bi at the octahedral site. Bismuth enhances ferromagnetism due to a decrease of the Co2+-Co2+ antiferromagnetic interactions and an increase of the Mn3+-Mn4+ exchanges. Spurious phases (magnetic and/or nonmagnetic oxides) can easily form because of the large differences between the ionic radii of Bi3+ and Co3+, hiding or altering the intrinsic physical properties of the main BixCo2-xMnO4 phase. An easy way to eliminate the secondary phases is using acid reagents. Short-time etching of Bi0.1Co1.9MnO4 using nitric acid was successfully used, keeping most of the properties of the initial compound, with no alteration of the crystallographic structure. Final stoichiometry was respected (˜Bi0.08Co1.82MnO4), meaning that the material after etching definitely contains bismuth elements in its structure and the observed properties are intrinsic to the oxide spinel. Additional experiments were performed as a function of the synthesis conditions, showing that an optimal pH value of 7 allowed the best magnetic response of the non-doped material.

dos Santos, M. E.; Lisboa-Filho, P. N.; Gouttefangeas, F.; Peña, O.

2013-08-01

339

Real-time imaging of DNA damage in yeast cells using ultra-short near-infrared pulsed laser irradiation.  

PubMed

Analysis of accumulation of repair and checkpoint proteins at repair sites in yeast nuclei has conventionally used chemical agents, ionizing radiation or induction of endonucleases to inflict localized damage. In addition to these methods, similar studies in mammalian cells have used laser irradiation, which has the advantage that damage is inflicted at a specific nuclear region and at a precise time, and this allows accurate kinetic analysis of protein accumulation at DNA damage sites. We show here that it is feasible to use short pulses of near-infrared laser irradiation to inflict DNA damage in subnuclear regions of yeast nuclei by multiphoton absorption. In conjunction with use of fluorescently-tagged proteins, this allows quantitative analysis of protein accumulation at damage sites within seconds of damage induction. PCNA accumulated at damage sites rapidly, such that maximum accumulation was seen approximately 50 s after damage, then levels declined linearly over 200-1000 s after irradiation. RPA accumulated with slower kinetics such that hardly any accumulation was detected within 60 s of irradiation, and levels subsequently increased linearly over the next 900 s, after which levels were approximately constant (up to ca. 2700 s) at the damage site. This approach complements existing methodologies to allow analysis of key damage sensors and chromatin modification changes occurring within seconds of damage inception. PMID:25409521

Guarino, Estrella; Cojoc, Gheorghe; García-Ulloa, Alfonso; Toli?, Iva M; Kearsey, Stephen E

2014-01-01

340

First-order virial expansion of short-time diffusion and sedimentation coefficients of permeable particles suspensions  

E-print Network

For suspensions of permeable particles, the short-time translational and rotational self-diffusion coefficients, and collective diffusion and sedimentation coefficients are evaluated theoretically. An individual particle is modeled as a uniformly permeable sphere of a given permeability, with the internal solvent flow described by the Debye-Bueche-Brinkman equation. The particles are assumed to interact non-hydrodynamically by their excluded volumes. The virial expansion of the transport properties in powers of the volume fraction is performed up to the two-particle level. The first-order virial coefficients corresponding to two-body hydrodynamic interactions are evaluated with very high accuracy by the series expansion in inverse powers of the inter-particle distance. Results are obtained and discussed for a wide range of the ratio, x, of the particle radius to the hydrodynamic screening length inside a permeable sphere. It is shown that for x >= 10, the virial coefficients of the transport properties are well-approximated by the hydrodynamic radius (annulus) model developed by us earlier for the effective viscosity of porous-particle suspensions.

Bogdan Cichocki; Maria L. Ekiel-Jezewska; G. Naegele; E. Wajnryb

2011-01-23

341

Short-term light adaptation of a cyanobacterium, Synechocystis sp. PCC 6803, probed by time-resolved fluorescence spectroscopy.  

PubMed

In photosynthetic organisms, the interactions among pigment-protein complexes change in response to light conditions. In the present study, we analyzed the transfer of excitation energy from the phycobilisome (PBS) and photosystem (PS) II to PSI in the cyanobacterium Synechocystis sp. PCC 6803. After 20 min of dark adaptation, Synechocystis cells were illuminated for 5 min with strong light with different spectral profiles, blue, green, two kinds of red, and white light. After illumination, the energy-transfer characteristics were evaluated using steady-state fluorescence and picosecond time-resolved fluorescence spectroscopy techniques. The fluorescence rise and decay curves were analyzed by global analysis to obtain fluorescence decay-associated spectra, followed by spectral component analysis. Under illumination with strong light, the contribution of the energy transfer from the PSII to PSI (spillover) became greater, and that of the energy transfer from the PBS to PSI decreased; the former change was larger than the latter. The energy transfer pathway to PSI was sensitive to red light. We discuss the short-term adaptation of energy-transfer processes in Synechocystis under strong-light conditions. PMID:24495908

Akimoto, Seiji; Yokono, Makio; Yokono, Erina; Aikawa, Shimpei; Kondo, Akihiko

2014-08-01

342

In vitro trans-scleral iontophoresis of methylprednisolone hemisuccinate with short application time and high drug concentration.  

PubMed

Trans-scleral iontophoresis, i.e. the application of small electric current to enhance drug transport across sclera is an option for non-invasive delivery of corticosteroids to the posterior segment of the eye. In this paper, in vitro trans-scleral iontophoresis of methylprednisolone hemisuccinate was investigated using concentrated drug solutions and short application times to mimic the iontophoretic conditions of in vivo studies. The drug at the donor concentration of 45 mg/ml was delivered through isolated porcine sclera under passive and iontophoretic conditions (cathodal, 2.4 mA) for 2-15 min. In a second set of experiments, the drug was delivered for 5 min at current intensities of 0.9-7.2 mA. After donor removal, drug release was followed up to 24 h. The exposure of concentrated solutions to sclera for 2-15 min under passive conditions caused a notable accumulation of drug up to 0.8 mg/cm², the release of which was successively followed for 24 h. In cathodal iontophoresis, the amount of accumulated drug increased proportionally to the charge between 0.3 and 1.44 Coulomb. When the charge was increased to 2.16 Coulomb by increasing the application time or current intensity, no further enhancement was recorded. This behaviour can be ascribed to substantial drug adsorption on the scleral tissue, as demonstrated through streaming potential studies, with the consequent increase of the electroosmotic flow that opposes drug transport. The set up suggested here could help in defining the optimal conditions for in vivo studies with animal models and reducing the number of in vivo experiments. PMID:23628405

Pescina, S; Martini, D; Santi, P; Padula, C; Murtomäki, L; Nicoli, S

2013-07-15

343

Timing in free-living rufous hummingbirds, Selasphorus rufus.  

PubMed

Animals organize their lives around circannual and circadian rhythms, but little is known of their use of much shorter intervals. In the laboratory, some animals can learn the specific duration (seconds or minutes) between periods of food access. It has been supposed that wild nectarivores, such as hummingbirds, might also learn short time intervals so as to avoid revisiting emptied flowers until the nectar has been replenished. We provided free-living, territorial rufous hummingbirds each with eight artificial flowers containing sucrose solution. Four flowers were refilled 10 min after the bird emptied them, and the other four were refilled 20 min after being emptied. Throughout the day, birds revisited the 10 min flowers significantly sooner than they revisited the 20 min flowers, and return visits to the flowers matched their refill schedules. Hummingbirds remembered the locations and timing of eight rewards, updating this information throughout the day. Not only is this the first time that this degree of timing ability has been shown in wild animals, but these hummingbirds also exhibit two of the fundamental aspects of episodic-like memory (where and when), the kind of memory for specific events often thought to be exclusive to humans. PMID:16527747

Henderson, Jonathan; Hurly, T Andrew; Bateson, Melissa; Healy, Susan D

2006-03-01

344

Multi-physics investigation on the failure mechanism and short-time scale wave motion in flip-chip configuration  

E-print Network

employed to characterize the waves and the various failure modes associated with the moving of these short-lived dynamical disturbances in bulk materials and along interfaces. A qualitative measure for failure was also developed which enables the extent...

Oh, Yoonchan

2005-11-01

345

Short contact time direct coal liquefaction using a novel batch reactor. Quarterly technical progress report, September 15, 1995--January 15, 1996  

SciTech Connect

The objective of this research is to optimize the design and operation of the bench scale batch reactor (SCTBR) f or coal liquefaction at short contact times (0.01 to 10 minutes or longer). Additional objectives are to study the kinetics of direct coal liquefaction particularly at short reaction times, and to investigate the role of the organic oxygen components of coal and their reaction pathways during liquefaction. Many of those objectives have already been achieved and others are still in progress. This quarterly report covers further progress toward those objectives.

Klein, M.T.; Calkins, W.H.; Huang, He

1996-01-26

346

Balancing the Need for Reliability and Time Efficiency: Short Forms of the Wechsler Adult Intelligence Scale-III  

Microsoft Academic Search

Tables permitting the conversion of short-form composite scores to full-scale IQ estimates have been published for previous editions of the Wechsler Adult Intelligence Scale (WAIS). Equivalent tables are now needed for selected subtests of the WAIS-III. This article used Tellegen and Briggs’s formulae to convert the sum of scaled scores for four selected WAIS-III short-form combinations into full-scale IQ estimates.

Sharon L. E. Jeyakumar; Erin M. Warriner; Vaishali V. Raval; Saadia A. Ahmad

2004-01-01

347

Second-phase validation study of short time exposure test for assessment of eye irritation potency of chemicals.  

PubMed

A Short Time Exposure (STE) test is a cytotoxicity test that uses SIRC cells (rabbit corneal cell line) to assess eye irritation potency following a 5-min chemical exposure. This second-phase validation study assessed the predictive capacity of the STE test using 40 coded test substances at three laboratories. A Validation Management Team (VMT) then evaluated the predictivity of the STE test for United Nation (UN) Globally Harmonized System (GHS) categories using 63 test substances including the results of the first-phase validation study. The STE test can assess not only the severe or corrosive ocular irritants (corresponding to the UN GHS Category 1) but also non-irritant (corresponding to UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. The predictivity by STE test, however, was insufficient for identification of UN GHS categories (Category 1, Category 2, or Non Category). These results suggest that the STE test can be recommended as an initial step in a top-down approach to identification of severe irritants and test substances that require classification for eye irritation (UN GHS Category 1) as well as an initial step in a bottom-up approach to identification of test substances that do not require classification for eye irritation (UN GHS Non Category) from other toxicity classes, especially for limited types of test substances. On the other hand, the STE test is not considered adequate for the identification of mild or moderate irritants (i.e., UN GHS Categories 2A and 2B) and severe irritants (UN GHS Category 1). PMID:23747838

Kojima, Hajime; Hayashi, Kazuhiko; Sakaguchi, Hitoshi; Omori, Takashi; Otoizumi, Takuya; Sozu, Takashi; Kuwahara, Hirofumi; Hayashi, Takumi; Sakaguchi, Mayumi; Toyoda, Akemi; Goto, Haruka; Watanabe, Shinichi; Ahiko, Kyoko; Nakamura, Tsuneaki; Morimoto, Takashi

2013-09-01

348

Successful operation of continuous reactors at short retention times results in high-density, fast-rate Dehalococcoides dechlorinating cultures.  

PubMed

The discovery of Dehalococcoides mccartyi reducing perchloroethene and trichloroethene (TCE) to ethene was a key landmark for bioremediation applications at contaminated sites. D. mccartyi-containing cultures are typically grown in batch-fed reactors. On the other hand, continuous cultivation of these microorganisms has been described only at long hydraulic retention times (HRTs). We report the cultivation of a representative D. mccartyi-containing culture in continuous stirred-tank reactors (CSTRs) at a short, 3-d HRT, using TCE as the electron acceptor. We successfully operated 3-d HRT CSTRs for up to 120 days and observed sustained dechlorination of TCE at influent concentrations of 1 and 2 mM TCE to ? 97 % ethene, coupled to the production of 10(12) D. mccartyi cells Lculture (-1). These outcomes were possible in part by using a medium with low bicarbonate concentrations (5 mM) to minimize the excessive proliferation of microorganisms that use bicarbonate as an electron acceptor and compete with D. mccartyi for H2. The maximum conversion rates for the CSTR-produced culture were 0.13 ± 0.016, 0.06 ± 0.018, and 0.02 ± 0.007 mmol Cl(-) Lculture (-1) h(-1), respectively, for TCE, cis-dichloroethene, and vinyl chloride. The CSTR operation described here provides the fastest laboratory cultivation rate of high-cell density Dehalococcoides cultures reported in the literature to date. This cultivation method provides a fundamental scientific platform for potential future operations of such a system at larger scales. PMID:24085396

Delgado, Anca G; Fajardo-Williams, Devyn; Popat, Sudeep C; Torres, César I; Krajmalnik-Brown, Rosa

2014-03-01

349

A voxel-based investigation for MRI-only radiotherapy of the brain using ultra short echo times.  

PubMed

Radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, so-called MRI-only RT, would remove the systematic registration error between MR and computed tomography (CT), and provide co-registered MRI for assessment of treatment response and adaptive RT. Electron densities, however, need to be assigned to the MRI images for dose calculation and patient setup based on digitally reconstructed radiographs (DRRs). Here, we investigate the geometric and dosimetric performance for a number of popular voxel-based methods to generate a so-called pseudo CT (pCT).Five patients receiving cranial irradiation, each containing a co-registered MRI and CT scan, were included. An ultra short echo time MRI sequence for bone visualization was used. Six methods were investigated for three popular types of voxel-based approaches; (1) threshold-based segmentation, (2) Bayesian segmentation and (3) statistical regression. Each approach contained two methods. Approach 1 used bulk density assignment of MRI voxels into air, soft tissue and bone based on logical masks and the transverse relaxation time T2 of the bone. Approach 2 used similar bulk density assignments with Bayesian statistics including or excluding additional spatial information. Approach 3 used a statistical regression correlating MRI voxels with their corresponding CT voxels. A similar photon and proton treatment plan was generated for a target positioned between the nasal cavity and the brainstem for all patients. The CT agreement with the pCT of each method was quantified and compared with the other methods geometrically and dosimetrically using both a number of reported metrics and introducing some novel metrics.The best geometrical agreement with CT was obtained with the statistical regression methods which performed significantly better than the threshold and Bayesian segmentation methods (excluding spatial information). All methods agreed significantly better with CT than a reference water MRI comparison. The mean dosimetric deviation for photons and protons compared to the CT was about 2% and highest in the gradient dose region of the brainstem. Both the threshold based method and the statistical regression methods showed the highest dosimetrical agreement.Generation of pCTs using statistical regression seems to be the most promising candidate for MRI-only RT of the brain. Further, the total amount of different tissues needs to be taken into account for dosimetric considerations regardless of their correct geometrical position. PMID:25393873

Edmund, Jens M; Kjer, Hans M; Van Leemput, Koen; Hansen, Rasmus H; Andersen, Jon Al; Andreasen, Daniel

2014-12-01

350

Revisiting the UK Muslim diasporic public sphere at a time of terror: from local (benign) invisible spaces to seditious conspiratorial spaces and the ‘failure of multiculturalism’ discourse  

Microsoft Academic Search

Public exposés of hidden spaces where diasporic Muslims allegedly enunciate extreme anti?Western rhetoric or plot sedition, highlight an ironic shift from a time, analysed in my earlier work, when the Pakistani diasporic public sphere in Britain was invisible and local while nevertheless being regarded as relatively benign: a space of expressive rhetoric, ceremonial celebration and local power struggles. Suicide bombings

Pnina Werbner

2009-01-01

351

The Revolving Door Phenomenon Revisited: Time to Readmission in 17'415 Patients with 37'697 Hospitalisations at a German Psychiatric Hospital  

PubMed Central

Objective Despite the recurring nature of the disease process in many psychiatric patients, individual careers and time to readmission rarely have been analysed by statistical models that incorporate sequence and velocity of recurrent hospitalisations. This study aims at comparing four statistical models specifically designed for recurrent event history analysis and evaluating the potential impact of predictor variables from different sources (patient, treatment process, social environment). Method The so called Andersen-Gil counting process model, two variants of the conditional models of Prentice, Williams, and Peterson (gap time model, conditional probability model), and the so called frailty model were applied to a dataset of 17’415 patients observed during a 12 years period starting from 1996 and leading to 37’697 psychiatric hospitalisations. Potential prognostic factors stem from a standardized patient documentation form. Results Estimated regression coefficients over different models were highly similar, but the frailty model best represented the sequentiality of individual treatment careers and differing velocities of disease progression. It also avoided otherwise likely misinterpretations of the impact of gender, partnership, historical time and length of stay. A widespread notion of psychiatric diseases as inevitably chronic and worsening could be rejected. Time in community was found to increase over historical time for all patients. Most important protective factors beyond diagnosis were employment, partnership, and sheltered living situation. Risky conditions were urban living and a concurrent substance use disorder. Conclusion Prognostic factors for course of diseases should be determined only by statistical models capable of adequately incorporating the recurrent nature of psychiatric illnesses. PMID:24116059

Frick, Ulrich; Frick, Hannah; Langguth, Berthold; Landgrebe, Michael; Hubner-Liebermann, Bettina; Hajak, Goran

2013-01-01

352

Searle's"Dualism Revisited"  

SciTech Connect

A recent article in which John Searle claims to refute dualism is examined from a scientific perspective. John Searle begins his recent article 'Dualism Revisited' by stating his belief that the philosophical problem of consciousness has a scientific solution. He then claims to refute dualism. It is therefore appropriate to examine his arguments against dualism from a scientific perspective. Scientific physical theories contain two kinds of descriptions: (1) Descriptions of our empirical findings, expressed in an every-day language that allows us communicate to each other our sensory experiences pertaining to what we have done and what we have learned; and (2) Descriptions of a theoretical model, expressed in a mathematical language that allows us to communicate to each other certain ideas that exist in our mathematical imaginations, and that are believed to represent, within our streams of consciousness, certain aspects of reality that we deem to exist independently of their being perceived by any human observer. These two parts of our scientific description correspond to the two aspects of our general contemporary dualistic understanding of the total reality in which we are imbedded, namely the empirical-mental aspect and the theoretical-physical aspect. The duality question is whether this general dualistic understanding of ourselves should be regarded as false in some important philosophical or scientific sense.

P., Henry

2008-11-20

353

TRADES: a new software to derive orbital parameters from observed Transit Times and Radial Velocities. Revisiting Kepler-11 and Kepler-9  

E-print Network

Aims. With the purpose of determining the orbital parameters of exoplanetary systems from observational data, we have developed a software, named TRADES (TRAnsits and Dynamics of Exoplanetary Systems) to simultaneously fit observed radial velocities and transit times data. Methods. We implemented a dynamical simulator for N-body system which also fits the available data during the orbital integration and determines the best combination of the orbital parameters using grid search, $\\chi^2$ minimization, genetic algorithms, particle swarm optimization, and bootstrap analysis. Results. To validate TRADES, we tested the code on a synthetic three-body system and on two real systems discovered by the Kepler mission: Kepler-9 and Kepler-11. These systems are good benchmarks to test multiple exoplanet systems showing transit time variations (TTVs) due to the gravitational interaction among planets. We have found orbital parameters of Kepler-11 planets in good agreement with the values proposed in the discovery paper ...

Borsato, Luca; Nascimbeni, Valerio; Piotto, Giampaolo; Granata, Valentina; Bedin, Luigi Rolly; Malavolta, Luca

2014-01-01

354

Revisiting a Sample of U.S. Billionaires: How Sample Selection and Timing of Maternal Condition Influence Findings on the Trivers-Willard Effect  

PubMed Central

Based on evolutionary theory, Trivers & Willard (TW) predicted the existence of mechanisms that lead parents with high levels of resources to bias offspring sex composition to favor sons and parents with low levels of resources to favor daughters. This hypothesis has been tested in samples of wealthy individuals but with mixed results. Here, I argue that both sample selection due to a high number of missing cases and a lacking specification of the timing of wealth accumulation contribute to this equivocal pattern. This study improves on both issues: First, analyses are based on a data set of U.S. billionaires with near-complete information on the sex of offspring. Second, subgroups of billionaires are distinguished according to the timing when they acquired their wealth. Informed by recent insights on the timing of a potential TW effect in animal studies, I state two hypotheses. First, billionaires have a higher share of male offspring than the general population. Second, this effect is larger for heirs and heiresses who are wealthy at the time of conception of all of their children than for self-made billionaires who acquired their wealth during their adult lives, that is, after some or all of their children have already been conceived. Results do not support the first hypothesis for all subgroups of billionaires. But for males, results are weakly consistent with the second hypothesis: Heirs but not self-made billionaires have a higher share of male offspring than the U.S. population. Heiresses, on the other hand, have a much lower share of male offspring than the U.S. average. This hints to a possible interplay of at least two mechanisms affecting sex composition. Implications for future research that would allow disentangling the distinct mechanisms are discussed. PMID:23437389

Schnettler, Sebastian

2013-01-01

355

TRADES: A new software to derive orbital parameters from observed transit times and radial velocities. Revisiting Kepler-11 and Kepler-9  

NASA Astrophysics Data System (ADS)

Aims: With the purpose of determining the orbital parameters of exoplanetary systems from observational data, we have developed a software, named TRADES (TRAnsits and Dynamics of Exoplanetary Systems), to simultaneously fit observed radial velocities and transit times data. Methods: We implemented a dynamical simulator for N-body systems, which also fits the available data during the orbital integration and determines the best combination of the orbital parameters using grid search, ?2 minimization, genetic algorithms, particle swarm optimization, and bootstrap analysis. Results: To validate TRADES, we tested the code on a synthetic three-body system and on two real systems discovered by the Kepler mission: Kepler-9 and Kepler-11. These systems are good benchmarks to test multiple exoplanet systems showing transit time variations (TTVs) due to the gravitational interaction among planets. We have found that orbital parameters of Kepler-11 planets agree well with the values proposed in the discovery paper and with a a recent work from the same authors. We analyzed the first three quarters of Kepler-9 system and found parameters in partial agreement with discovery paper. Analyzing transit times (T0s), covering 12 quarters of Kepler data, that we have found a new best-fit solution. This solution outputs masses that are about 55% of the values proposed in the discovery paper; this leads to a reduced semi-amplitude of the radial velocities of about 12.80 ms-1.

Borsato, L.; Marzari, F.; Nascimbeni, V.; Piotto, G.; Granata, V.; Bedin, L. R.; Malavolta, L.

2014-11-01

356

Internet Governance revisited: Think decentralization!  

E-print Network

Internet Governance revisited: Think decentralization! Brown-bag presentation given at the National Administration of the core technical resources of the Internet: ICANN: The mission... ,,preserving the public of the Internet" #12;unique identifiers basis for accurate routing of information (TCP/IP) IP-blocks managed

Schweik, Charles M.

357

PSOS Revisited Peter G. Neumann  

E-print Network

PSOS Revisited Peter G. Neumann Computer Science Laboratory SRI International Menlo Park CA 94025 This paper provides a retrospective view of the design of SRI's Provably Secure Operating System (PSOS), a for- mally specified tagged-capability hierarchical system ar- chitecture. It examines PSOS

Neumann, Peter G.

358

Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner  

DOEpatents

An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90.degree. angle of incidence.

Veligdan, James T. (Manorville, NY)

1994-01-01

359

The linkages among hillslope-vegetation changes, elevation, and the timing of late-Quaternary fluvial-system aggradation in the Mojave Desert revisited  

NASA Astrophysics Data System (ADS)

Valley-floor-channel and alluvial-fan deposits and terraces in the southwestern US record multiple episodes of late-Quaternary fluvial-system aggradation and incision. Perhaps the most well-constrained of these episodes took place from the latest Pleistocene to the present in the Mojave Desert. One hypothesis for this episode - i.e., the paleovegetation-change hypothesis (PVCH) - posits that a reduction in hillslope vegetation cover associated with the transition from Pleistocene woodlands to Holocene desert scrub generated a pulse of sediment that triggered a primary phase of aggradation downstream, followed by channel incision, terrace abandonment, and initiation of a secondary phase of aggradation further downstream. A second hypothesis - i.e., the extreme-storm hypothesis - attributes episodes of aggradation and incision to changes in the frequency and/or intensity of extreme storms. In the past decade a growing number of studies has advocated the extreme-storm hypothesis and challenged the PVCH on the basis of inconsistencies in both timing and process. Here I show that in eight out of nine sites where the timing of fluvial-system aggradation in the Mojave Desert is reasonably well constrained, measured ages of primary aggradation are consistent with the predictions of the PVCH if the time-transgressive nature of paleovegetation changes with elevation is fully taken into account. I also present an alternative process model for PVCH that is more consistent with available data and produces sediment pulses primarily via an increase in drainage density (i.e., a transformation of hillslopes into low-order channels) rather than solely via an increase in sediment yield from hillslopes. This paper further documents the likely important role of changes in upland vegetation cover and drainage density in driving fluvial-system response during semiarid-to-arid climatic changes.

Pelletier, J. D.

2014-08-01

360

Using the Advanced Progressive Matrices (Set I) to Assess Fluid Ability in a Short Time Frame: An Item Response Theory-Based Analysis  

ERIC Educational Resources Information Center

This article is aimed at evaluating the possibility that Set I of the Advanced Progressive Matrices (APM-Set I) can be employed to assess fluid ability in a short time frame. The APM-Set I was administered to a sample of 1,389 primary and secondary school students. Confirmatory factor analysis attested to the unidimensionality of the scale. Item…

Chiesi, Francesca; Ciancaleoni, Matteo; Galli, Silvia; Primi, Caterina

2012-01-01

361

Changes in Children's Perception-Action Tuning over Short Time Scales: Bicycling across Traffic-Filled Intersections in a Virtual Environment  

ERIC Educational Resources Information Center

This investigation examined short-term changes in child and adult cyclists' gap decisions and movement timing in response to general and specific road-crossing experiences. Children (10- and 12-year-olds) and adults rode a bicycle through a virtual environment with 12 intersections. Participants faced continuous cross traffic and waited for gaps…

Plumert, Jodie M.; Kearney, Joseph K.; Cremer, James F.; Recker, Kara M.; Strutt, Jonathan

2011-01-01

362

On the use of petrology to characterize shallow degassing and microlite textures from vulcanian tephra in short time windows of eruption at Popocatepetl Volcano, Mexico  

Microsoft Academic Search

Popocatepetl volcano is located close to densely populated areas (Mexico City and Puebla metropolitan area), and therefore, evaluation of hazards associated with explosive eruptions is crucial. It is important to be able to monitor changes in eruption style (explosive to dome building) within a short period of time. In this work we present detailed textural and compositional data for ashes

J. Roberge; H. Delgado Granados; C. Linares Lopez; M. A. Reyes Salas; P. Wallace

2006-01-01

363

DEWEK Wind Energy Conference 2012 Category: 4. Simulation models BACKWARD EXTRAPOLATION OF SHORT-TIME MEASUREMENT DATA FOR A REMAINING SERVICE LIFE ESTIMATION OF WIND  

E-print Network

DEWEK Wind Energy Conference 2012 Category: 4. Simulation models 1 BACKWARD EXTRAPOLATION OF SHORT-TIME MEASUREMENT DATA FOR A REMAINING SERVICE LIFE ESTIMATION OF WIND TURBINES Dipl.-Ing. René Kamieth, Prof. Dr, Germany, Tel.: +49-(0)30-314-23603, Fax: +49-(0)30-314-26131 Summary Wind turbines built in the last

Berlin,Technische Universität

364

Richards model revisited: validation by and application to infection dynamics.  

PubMed

Ever since Richards proposed his flexible growth function more than half a century ago, it has been a mystery that this empirical function has made many incredible coincidences with real ecological or epidemic data even though one of its parameters (i.e., the exponential term) does not seem to have clear biological meaning. It is therefore a natural challenge to mathematical biologists to provide an explanation of the interesting coincidences and a biological interpretation of the parameter. Here we start from a simple epidemic SIR model to revisit Richards model via an intrinsic relation between both models. Especially, we prove that the exponential term in the Richards model has a one-to-one nonlinear correspondence to the basic reproduction number of the SIR model. This one-to-one relation provides us an explicit formula in calculating the basic reproduction number. Another biological significance of our study is the observation that the peak time is approximately just a serial interval after the turning point. Moreover, we provide an explicit relation between final outbreak size, basic reproduction number and the peak epidemic size which means that we can predict the final outbreak size shortly after the peak time. Finally, we introduce a constraint in Richards model to address over fitting problem observed in the existing studies and then apply our method with constraint to conduct some validation analysis using the data of recent outbreaks of prototype infectious diseases such as Canada 2009 H1N1 outbreak, GTA 2003 SARS outbreak, Singapore 2005 dengue outbreak, and Taiwan 2003 SARS outbreak. Our new formula gives much more stable and precise estimate of model parameters and key epidemic characteristics such as the final outbreak size, the basic reproduction number, and the turning point, compared with earlier simulations without constraints. PMID:22889641

Wang, Xiang-Sheng; Wu, Jianhong; Yang, Yong

2012-11-21

365

Balancing the Need for Reliability and Time Efficiency: Short Forms of the Wechsler Adult Intelligence Scale-III  

ERIC Educational Resources Information Center

Tables permitting the conversion of short-form composite scores to full-scale IQ estimates have been published for previous editions of the Wechsler Adult Intelligence Scale (WAIS). Equivalent tables are now needed for selected subtests of the WAIS-III. This article used Tellegen and Briggs's formulae to convert the sum of scaled scores for four…

Jeyakumar, Sharon L. E.; Warriner, Erin M.; Raval, Vaishali V.; Ahmad, Saadia A.

2004-01-01

366

Evidence for the stimulation of field-aligned electron density irregularities on a short time scale by ionospheric topside sounders  

Microsoft Academic Search

Ionospheric topside sounders can be considered to act as mobile ionospheric heating facilities. They stimulate a wide variety of plasma phenomena that suggests that significant plasma heating can be produced in the vicinity of the spacecraft following the short duration (0.1 ms) high-power (hundreds of watts) sounder pulse. Most of these phenomena are sensitive to the ambient plasma conditions, particularly

Robert F. Benson

1997-01-01

367

Magnetic resonance imaging (MRI) of solid materials entails numerous problems from short longitudinal relaxation (T2) times to  

E-print Network

Magnetic resonance imaging (MRI) of solid materials entails numerous problems from short advantages over conventional MRI procedures such as more stable and stronger gradients (> 50 T/m), and finer the metal foils on the 1D profile. High-Resolution MRI Probe for STRAFI Studies of Solid Materials Joel A

Weston, Ken

368

"In Loco Parentis" Revisited?  

ERIC Educational Resources Information Center

Suggests that many students are not aware of proper etiquette and proposes that business communication instructors offer a short bibliography and a few tips that can help students acquire more polish. (DF)

Murphree, Carolyn T.

1986-01-01

369

The P600-as-P3 hypothesis revisited: Single-trial analyses reveal that the late EEG positivity following linguistically deviant material is reaction time aligned.  

PubMed

The P600, a late positive ERP component following linguistically deviant stimuli, is commonly seen as indexing structural, high-level processes, e.g. of linguistic (re)analysis. It has also been identified with the P3 (P600-as-P3 hypothesis), which is thought to reflect a systemic neuromodulator release facilitating behavioural shifts and is usually response time aligned. We investigated single-trial alignment of the P600 to response, a critical prediction of the P600-as-P3 hypothesis. Participants heard sentences containing morphosyntactic and semantic violations and responded via a button press. The elicited P600 was perfectly response aligned, while an N400 following semantic deviations was stimulus aligned. This is, to our knowledge, the first single-trial analysis of language processing data using within-sentence behavioural responses as temporal covariates. Results support the P600-as-P3 perspective and thus constitute a step towards a neurophysiological grounding of language-related ERPs. PMID:25151545

Sassenhagen, Jona; Schlesewsky, Matthias; Bornkessel-Schlesewsky, Ina

2014-10-01

370

Heliocentric Distance of Coronal Mass Ejections at the Time of Energetic Particle Release: Revisiting the Ground Level Enhancement Events of Solar Cycle 23  

NASA Technical Reports Server (NTRS)

Using the kinematics of coronal mass ejections (CMEs), onset time of soft X-ray flares, and the finite size of the pre-eruption CME structure, we derive the heliocentric distane at which the energetic particles during the ground level enhancement (GLE) events of Solar Cycle 23. We find that the GLE particles are released when the CMEs reach an average heliocentric distance of approx.3.25 solar radii (Rs). From this we infer that the shocks accelerating the particles are located at similar heights. Type II radio burst observations indicate that the CMEs are at much lower distances (average approx.1.4 Rs) when the CME-driven shock first forms. The shock seems to travel approx.1.8 Rs over a period of approox.30 min on the average before releasing the GLE particles. In deriving these results, we made three assumptions that have observational support: (i) the CME lift off occurs from an initial distance of about 1.25 Rs; (ii) the flare onset and CME onset are one and the same because these are two different manifestations of the same eruption; and (iii) the CME has positive acceleration from the onset to the first appearance in the coronagraphic field of view (2.5 to 6 Rs). Observations of coronal cavities in eclipse pictures and in coronagraphic images justify the assumption (i). The close relationship between the flare reconnection magnetic flux and the azimuthal flux of interplanetary magnetic clouds justify assumption (ii) consistent with the standard model (CSHKP) of solar eruption. Coronagraphic observations made close to the solar surface indicate a large positive acceleration of CMEs to a heliocentric distance of approx.3 Rs before they start slowing down due to the drag force. The inferred acceleration (approx.1.5 km/s/s) is consistent with reported values in the literature.

Gopalswamy, Natchimuthuk

2011-01-01

371

Time-dependent theory of Auger decay induced by ultra-short pulses in a strong laser field  

Microsoft Academic Search

A quantum mechanical theory of a laser-assisted Auger process in atoms excited by an ultra-short (attosecond) electromagnetic pulse in the field of a few-cycle strong laser pulse is presented. It is based on the non-stationary Schrödinger equation, which describes the photoionization of an inner atomic shell and the decay of the created vacancy, while the Auger electron is treated in

A K Kazansky; I P Sazhina; N M Kabachnik

2009-01-01

372

Means and method for characterizing high power, ultra short laser pulses in a real time, on line manner  

DOEpatents

An ultra short (<10 ps), high power laser pulse is temporally characterized by a system that uses a physical measurement of a wavefront that has been altered in a known manner. The system includes a first reflection switch to remove a portion of a pulse from a beam of pulses, then includes a second reflection switch, operating in a mode that is opposite to the first reflection switch, to slice off a portion of that removed portion. The sliced portion is then directed to a measuring device for physical measurement. The two reflection switches are arranged with respect to each other and with respect to the beam of ultra short pulses such that physical measurement of the sliced portion is related to the temporal measurement of the ultra short pulse by a geometric or trigonometric relationship. The reflection switches are operated by a control pulse that is directed to impinge on each of the reflection switches at a 90[degree] angle of incidence. 8 figures.

Veligdan, J.T.

1994-03-08

373

Distant future of the Sun and Earth revisited  

E-print Network

We revisit the distant future of the Sun and the solar system, based on stellar models computed with a thoroughly tested evolution code. For the solar giant stages, mass-loss by the cool (but not dust-driven) wind is considered in detail. Using the new and well-calibrated mass-loss formula of Schroder & Cuntz (2005, 2007), we find that the mass lost by the Sun as an RGB giant (0.332 M_Sun, 7.59 Gy from now) potentially gives planet Earth a significant orbital expansion, inversely proportional to the remaining solar mass. According to these solar evolution models, the closest encounter of planet Earth with the solar cool giant photosphere will occur during the tip-RGB phase. During this critical episode, for each time-step of the evolution model, we consider the loss of orbital angular momentum suffered by planet Earth from tidal interaction with the giant Sun, as well as dynamical drag in the lower chromosphere. We find that planet Earth will not be able to escape engulfment, despite the positive effect of solar mass-loss. In order to survive the solar tip-RGB phase, any hypothetical planet would require a present-day minimum orbital radius of about 1.15 AU. Furthermore, our solar evolution models with detailed mass-loss description predict that the resulting tip-AGB giant will not reach its tip-RGB size. The main reason is the more significant amount of mass lost already in the RGB phase of the Sun. Hence, the tip-AGB luminosity will come short of driving a final, dust-driven superwind, and there will be no regular solar planetary nebula (PN). But a last thermal pulse may produce a circumstellar (CS) shell similar to, but rather smaller than, that of the peculiar PN IC 2149 with an estimated total CS shell mass of just a few hundredths of a solar mass.

Klaus-Peter Schroder; Robert C. Smith

2008-01-25

374

Time to Revisit Crop Insurance Premium Subsidies?  

Microsoft Academic Search

In 2000, Congress decided to move away from a fixed-dollar-per-acre premium subsidy to a subsidy percentage that applies to any crop insurance product offered. This change reduced the cost to farmers of moving from yield insurance to revenue insurance by more than 50%. In addition, Congress decided to pay a large proportion of the additional premium for higher coverage levels,

Bruce A. Babcock

2011-01-01

375

Anticancer agents against malaria: time to revisit?  

PubMed Central

The emergence of artemisinin resistance could adversely impact the current strategy for malaria treatment; thus, new drugs are urgently needed. A possible approach to developing new antimalarials is to find new uses for old drugs. Some anticancer agents such as methotrexate and trimetrexate are active against malaria. However, they are commonly perceived to be toxic and thus not suitable for malaria treatment. In this opinion article, we examine how the toxicity of anticancer agents is just a matter of dose or ‘only dose makes the poison’, as coined in Paracelsus’ law. Thus, the opportunity exists to discover new antimalarials using the anticancer pharmacopoeia. PMID:20056487

Nzila, Alexis; Okombo, John; Becker, Ruy Perez; Chilengi, Roma; Lang, Trudie; Niehues, Tim

2010-01-01

376

Highly controlled synthesis of nanometric gold particles by citrate reduction using the short mixing, heating and quenching times achievable in a microfluidic device  

NASA Astrophysics Data System (ADS)

Homodispersed 1.8 nm gold nanoparticles were obtained reproducibly in high yields using the classical Turkevich protocol at a high concentration in a continuous flow capillary reactor. The microfluidic reactor made from commercially available items permitted short mixing, heating and quenching times which are the key parameters of this synthesis.Homodispersed 1.8 nm gold nanoparticles were obtained reproducibly in high yields using the classical Turkevich protocol at a high concentration in a continuous flow capillary reactor. The microfluidic reactor made from commercially available items permitted short mixing, heating and quenching times which are the key parameters of this synthesis. Electronic supplementary information (ESI) available: Description of the microfluidic device, protocol for gold nanoparticle synthesis in batch and in the microsystem, and gold nanoparticle size distribution raw data. See DOI: 10.1039/c2nr11666a

Ftouni, Jamal; Penhoat, Maël; Addad, Ahmed; Payen, Edmond; Rolando, Christian; Girardon, Jean-Sébastien

2012-07-01

377

Reply to comment on "A simple model for the short-time evolution of near-surface current and temperature profiles"  

E-print Network

This is our response to a comment by Walter Eifler on our paper `A simple model for the short-time evolution of near-surface current and temperature profiles' (arXiv:physics/0503186, accepted for publication in Deep-Sea Research II). Although Eifler raises genuine issues regarding our model's validity and applicability, we are nevertheless of the opinion that it is of value for the short-term evolution of the upper-ocean profiles of current and temperature. The fact that the effective eddy viscosity tends to infinity for infinite time under a steady wind stress may not be surprising. It can be interpreted as a vertical shift of the eddy viscosity profile and an increase in the size of the dominant turbulent eddies under the assumed conditions of small stratification and infinite water depth.

Jenkins, A D; Jenkins, Alastair D.; Ward, Brian

2005-01-01

378

Operational Near Real-Time Derivation of Land Surface Albedo and DownWelling Short-Wave Radiation from MSG Observations  

Microsoft Academic Search

In the framework of the EUMETSAT Satellite Applica- tion Facility for Land Surface Analysis (Land-SAF) we develop surface albedo and short-wave radiation products which will be generated in near real-time from observa- tions provided by the MSG\\/SEVIRI instrument. The albedo algorithm exploits the diurnal variation of the illumination angle, which provides information on the angular variation of reflectance, in order

B. Geiger; L. Franchistéguy; D. Lajas; J.-L. Roujean

2004-01-01

379

Specific features of growth and energetics of juvenile rainbow trout Parasalmo ( Oncorhynchus ) mykiss at constant temperature and its short-time periodic deviations into the upper suboptimal zone  

Microsoft Academic Search

It was shown that short-time periodical temperature fluctuations within the upper temperature zone suboptimal for the growth\\u000a of juvenile rainbow trout Parasalmo (Oncorhynchus) mykiss exerts a favorable effect on the growth and energetics of fish. Under variable temperature conditions, an increase in the\\u000a rate of growth and improvement of energetic and production indices of juvenile trout, as compared to constant

V. V. Zdanovich; V. Ya. Pushkar’; M. Z. Kelekhsaev

2011-01-01

380

Use of high-concentration-short-time chlorine dioxide gas treatments for the inactivation of Salmonella enterica spp. inoculated onto Roma tomatoes  

Microsoft Academic Search

Salmonella outbreaks have been recently linked to the consumption of fresh tomatoes. Thus, there is a need to develop systems that reduce the risk of microbial contamination to increase product shelf-life and keep fresh fruit attributes. The objectives of this study were to evaluate high-concentration-short-time chlorine dioxide gas treatments effects on Salmonella-inoculated Roma tomatoes and determine the optimal treatment conditions

V. Trinetta; M. T. Morgan; R. H. Linton

2010-01-01

381

Comparison of short- and long-term outcomes for aggressive spine rehabilitation delivered two versus three times per week  

Microsoft Academic Search

Background context: Rehabilitation services using intensive exercise for the treatment of chronic spinal pain have traditionally been scheduled at a frequency of three times per week.Purpose: In an attempt to reduce the cost of rehabilitation services, this study was designed to determine whether treatment offered two times per week could produce similar outcomes when compared with an established three times

James Rainville; Cristin A Jouve; Carol Hartigan; Eugenio Martinez; Mark Hipona

2002-01-01

382

Scope of high-frequency time keeping in searches for short-period gamma-ray sources  

Microsoft Academic Search

This paper presents a novel technique to derive the absolute time of occurrence of an event with an accuracy of less than 200 microsec by adapting the HF time synchronization technique to correct for the aging rate and the frequency drift of a temperature-controlled quartz frequency standard. The propagation delay suffered by the HF time signals has been estimated by

M. L. Sapru; A. K. Tickoo; I. K. Kaul; S. K. Kaul; C. L. Bhat

1990-01-01

383

Short wavelength magnetic buoyancy instability  

E-print Network

Magnetic buoyancy instability plays an important role in the evolution of astrophysical magnetic fields. Here we revisit the problem introduced by \\citet{Gilman_1970} of the short wavelength linear stability of a plane layer of compressible isothermal fluid permeated by a horizontal magnetic field of strength decreasing with height. Dissipation of momentum and magnetic field is neglected. By the use of a Rayleigh-Schr\\"odinger perturbation analysis, we explain in detail the limit in which the transverse horizontal wavenumber of the perturbation, denoted by $k$, is large (i.e.\\ short horizontal wavelength) and show that the fastest growing perturbations become localized in the vertical direction as $k$ is increased. The growth rates are determined by a function of the vertical coordinate $z$ since, in the large $k$ limit, the eigenmodes are strongly localized in the vertical direction. We consider in detail the case of two-dimensional perturbations varying in the directions perpendicular to the magnetic field,...

Mizerski, K A; Hughes, D W

2013-01-01

384

Scope of high-frequency time keeping in searches for short-period gamma-ray sources  

Microsoft Academic Search

This paper presents a novel technique to derive the absolute time of occurrence of an event with an accuracy of < 200 µs by\\u000a adapting the HF time synchronization technique to correct for the aging rate and the frequency drift of a temperature-controlled\\u000a quartz frequency standard. The propagation delay suffered by the HF time signals has been estimated by monitoring

M. L. Sapru; A. K. Tickoo; I. K. Kaul; S. K. Kaul; C. L. Bhat; R. K. Kaul; H. S. Rawat; V. K. Senecha; R. C. Rannot; H. Razdan

1990-01-01

385

Pair Production Constraints on Superluminal Neutrinos Revisited  

SciTech Connect

We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint. In summary, any model for which the CG pair production process operates is excluded because such timelike neutrinos would not be detected by OPERA or other experiments. However, a superluminal neutrino which is effectively lightlike with fixed p{sup 2} can evade the Cohen-Glashow constraint because of energy-momentum conservation. The coincidence involved in explaining the SN1987A constraint certainly makes such a picture improbable - but it is still intrinsically possible. The lightlike model is appealing in that it does not violate Lorentz symmetry in particle interactions, although one would expect Hughes-Drever tests to turn up a violation eventually. Other evasions of the CG constraints are also possible; perhaps, e.g., the neutrino takes a 'short cut' through extra dimensions or suffers anomalous acceleration in matter. Irrespective of the OPERA result, Lorentz-violating interactions remain possible, and ongoing experimental investigation of such possibilities should continue.

Brodsky, Stanley J.; /SLAC; Gardner, Susan; /Kentucky U.

2012-02-16

386

Coal liquefaction short residence time process research, 79-1. First quarterly report, October 1December 31, 1978  

Microsoft Academic Search

The bench scale coal liquefaction reactor is being modified to increase the accuracy of data required for kinetic studies, and to also extend the region of operation of the reactor. Preliminary concepts have been identified for residence time measurements and further studies are underway to evaluate performance under reaction conditions. Current concepts include: solid phase residence time--magnetic tracer particles or

R. K. Traeger; T. C. Bickel

1979-01-01

387

Human short-term exposure to electromagnetic fields emitted by mobile phones decreases computer-assisted visual reaction time.  

PubMed

The worldwide dramatic increase in mobile phone use has generated great concerns about the detrimental effects of microwave radiations emitted by these communication devices. Reaction time plays a critical role in performing tasks necessary to avoid hazards. As far as we know, this study is the first survey that reports decreased reaction time after exposure to electromagnetic fields generated by a high specific absorption rate mobile phone. It is also the first study in which previous history of mobile phone use is taken into account. The aim of this study was to assess both the acute and chronic effects of electromagnetic fields emitted by mobile phones on reaction time in university students. Visual reaction time (VRT) of young university students was recorded with a simple blind computer-assisted-VRT test, before and after a 10 min real/sham exposure to electromagnetic fields of mobile phones. Participants were 160 right-handed university students aged 18-31. To assess the effect of chronic exposures, the reaction time in sham-exposed phases were compared among low level, moderate and frequent users of mobile phones. The mean ± SD reaction time after real exposure and sham exposure were 286.78 ± 31.35 ms and 295.86 ± 32.17 ms (P < 0.001), respectively. The age of students did not significantly alter the reaction time either in talk or in standby mode. The reaction time either in talk or in standby mode was shorter in male students. The students' VRT was significantly affected by exposure to electromagnetic fields emitted by a mobile phone. It can be concluded that these exposures cause decreased reaction time, which may lead to a better response to different hazards. In this light, this phenomenon might decrease the chances of human errors and fatal accidents. PMID:22426673

Mortazavi, S M J; Rouintan, M S; Taeb, S; Dehghan, N; Ghaffarpanah, A A; Sadeghi, Z; Ghafouri, F

2012-06-01

388

Revisiting the Orion Nebula  

NASA Astrophysics Data System (ADS)

Orion the Hunter is perhaps the best-known constellation in the sky, well placed in the winter for observers in both the northern and southern hemispheres, and instantly recognisable. Just below Orion's belt (three distinctive stars in a row), the hilt of his sword holds a great jewel in the sky, the beautiful Orion Nebula. Bright enough to be seen with the naked eye, the nebula, also known as Messier 42, is a wide complex of gas and dust, illuminated by several massive and hot stars at its core, the famous Trapezium stars. For astronomers, Orion is surely one of the most important constellations, as it contains one of the nearest and most active stellar nurseries in the Milky Way, the galaxy in which we live. Here tens of thousands of new stars have formed within the past ten million years or so - a very short span of time in astronomical terms. For comparison: our own Sun is now 4,600 million years old and has not yet reached half-age. Reduced to a human time-scale, star formation in Orion would have been going on for just one month as compared to the Sun's 40 years. In fact, located at a distance of 1500 light years, the Orion Nebula plays such an important role in astrophysics that it can be argued that our understanding of star formation is for a large part based on the Orion Nebula. It is thus no surprise that the Orion Nebula is one of the most studied objects in the night sky (see for example the various related ESO Press Photos and Releases: ESO Press Photo 03a/98, ESO Press Photos 03a-d/01, ESO Press Photos 12a-e/01, ESO Press Release 14/01,...). The richness of the stellar cluster inside the Orion Nebula makes it an ideal, and unique, target for high resolution and wide-field imaging. Following some pioneering work made a few years ago, an international team of astronomers [1], led by Massimo Robberto (European Space Agency and Space Telescope Science Institute), used the Wide Field Imager (WFI), a 67-million pixel digital camera that is installed at the ESO/MPG 2.2m telescope at La Silla, to obtain very deep images of this region. ESO PR Photo 20/04 shows a false-colour composite of images obtained in four different wavebands (see technical information below). Among others, these observations allow the astronomers to measure the rates of mass that falls onto the young stars (the mass accretion rates) and to determine if it depends on the position of the stars in the cluster. If this were the case, it would indicate that the final stages of star formation are affected by the onset of ionising radiation from the most massive stars. From a preliminary study with the Hubble Space Telescope, the astronomers found that indeed the mass accretion rates are lower in the Orion Nebula Cluster than in other, more diffuse star-forming regions. The analysis of these new WFI images should allow confirmation of this hypothesis. The astronomers also obtained images of the Orion Nebula in several narrow-band filters corresponding to emission lines - hydrogen (Halpha), oxygen ([OIII]), and sulphur ([SII]) - enabling them to probe the morphology of the nebula in these prominent lines. It is rather obvious from the image that for example some regions are redder than others, providing the astronomers with important clues on the conditions prevailing in the nebula. In the next months, a large international collaboration also led by M. Robberto will use the Hubble Space Telescope to survey with unprecedented sensitivity (23-25 mag) and spatial resolution approximately 50% of the field imaged by the present WFI observations. The astronomers expect to discover and classify an unknown but substantial population of young double stars, low mass stars and brown dwarfs.

2004-06-01

389

Strong Poison Revisited  

SciTech Connect

Selenium in the form of selenocysteine plays an essential role in a number of proteins, but its role in non-enzymatic biochemistry is also important. In this short review we discuss the interactions between inorganic selenium, arsenic and mercury under physiological conditions, especially in the presence of glutathione. This chemistry is obviously important in making the arsenic and mercury unavailable for more toxic interactions, but in the process it suggests that a side-effect of chronic arsenic and/or mercury exposure is likely to be functional selenium deficiency.

Prince, R.C.; Gailer, J.; Gunson, D.E.; Turner, R.J.; George, G.N.; Pickering, I.J.

2009-06-04

390

Short time dissolution kinetics of refractory elements Fe, Al, and Ti in Asian outflow-impacted marine aerosols and implications  

NASA Astrophysics Data System (ADS)

A six-step sequential extraction protocol was employed for marine aerosols with varying mixture of dust and pollution particles collected from the East China Sea to study the dissolution kinetics of refractory elements Fe, Al, and Ti (with a focus on Fe) in relation to acidic substances such as sulfate, nitrate, and water-soluble organic carbon. The three elements might be of a natural origin such as Asian dust and/or anthropogenic origins such as coal fly ash and biomass burning; however, this study focused on the dissolution kinetics, instead of their sources. We selected three samples with varying dust loading but close acid loadings for the experiment so that the acidic effect on the aerosol Fe dissolution could be explored as the direct contribution of water-soluble Fe from anthropogenic sources, if any, might be constrained at a relatively constant level among the samples. Extraction was stepwise performed with six steps for total 30 min, and the leaching duration was as short as ten seconds in the first five steps. No saturation was found for the analyzed elements. Two phases of dissolution curves were observed in all interested compositions, which could be explained by an aged aerosol particle model, with an intrinsically insoluble core and weathered surface. The first phase curve approximates the first-order reaction, with considerably high dissolution rates of 6.5-277 ?mol g-1 min-1, indicating the likely existence of an “extremely fast iron pool” that may exist on the weathered surface of aged particles, along with other three pools proposed by Shi et al. (2011). Acid/dust ratio could be a crucial factor that facilitates parameterization of aerosol iron dissolution. Results of this study are useful in improving aerosol iron and other transition element dissolution schemes in atmospheric chemistry models.

Hsu, Shih-Chieh; Lin, Fei-Jan; Liu, Tsun-Hsien; Lin, Shuen-Hsin; Kao, Shuh-Ji; Tseng, Chun-Mao; Huang, Chao-Hao

2013-11-01

391

Short-term wave forecasting with AR models in real-time optimal control of wave energy converters  

Microsoft Academic Search

Time domain control of wave energy converters requires knowledge of future incident wave elevation in order to approach conditions for optimal energy extraction. Autoregressive models revealed to be a promising approach to the prediction of future values of the wave elevation only from its past history. Results on real wave observations from different ocean locations show that AR models allow

Francesco Fusco; John V. Ringwood

2010-01-01

392

Alteration in scaling behavior of short-term heartbeat time series for professional shooting athletes from rest to exercise  

Microsoft Academic Search

Scaling analysis of heartbeat time series has emerged as a useful tool for assessing the autonomic cardiac control under various physiologic and pathologic conditions. We study the heartbeat activity and scaling behavior of heartbeat fluctuations regulated by autonomic nervous system for professional shooting athletes under two states: rest and exercise, by applying the detrended fluctuation analysis method. We focus on

Jian Jun Zhuang; Xin Bao Ning; Ai Jun He; Ming Zou; Biao Sun; Xu Hui Wu

2008-01-01

393

Short time-scale spectral variability in the A0 supergiant HD 92207 and the importance of line profile variations for the interpretation of FORS 2 spectropolarimetric observations  

NASA Astrophysics Data System (ADS)

Our recent search for the presence of a magnetic field in the bright early A-type supergiant HD 92207 using FOcal reducer low dispersion spectrograph (FORS) 2 in spectropolarimetric mode indicated the presence of a longitudinal magnetic field of the order of a few hundred gauss. Assuming the ideal case of a non-variable star, this discovery has recently been questioned in one work trying to demonstrate the importance of non-photon noise in FORS 2 observations. The assumption of non-variability of HD 92207 can, however, not be held since substantial profile variations of diverse lines on a time-scale of minutes or maybe even a fraction of a minute are detected in FORS 2 spectra. The presence of short-term spectral variability in blue supergiants, which are considered as Type II supernova progenitors, has not been a subject of systematic studies before and is critical for the current theoretical understanding of their physics. Given the detected short-term variability, the question of the presence of a magnetic field cannot be answered without proper modelling of the impact of such a variability on the measurements of the magnetic field. Since the short-term periodicity does not fit into the currently known domain of non-radially pulsating supergiants, its confirmation is of great importance for models of stellar evolution.

Hubrig, S.; Schöller, M.; Kholtygin, A. F.

2014-05-01

394

Revisiting the Schrodinger probability current  

E-print Network

We revisit the definition of the probability current for the Schrodinger equation. First, we prove that the Dirac probability currents of stationary wave functions of the hydrogen atom and of the isotrop harmonic oscillator are not nil and correspond to a circular rotation of the probability. Then, we recall how it is necessary to add to classical Pauli and Schrodinger currents, an additional spin-dependant current, the Gordan current. Consequently, we get a circular probability current in the Schrodinger approximation for the hydrogen atom and the isotrop harmonic oscillator.

Michel Gondran; Alexandre Gondran

2003-04-08

395

Optical design of the short pulse x-ray imaging and microscopy time-angle correlated diffraction beamline at the Advanced Photon Source.  

PubMed

The short pulse x-ray imaging and microscopy beamline is one of the two x-ray beamlines that will take full advantage of the short pulse x-ray source in the Advanced Photon Source (APS) upgrade. A horizontally diffracting double crystal monochromator which includes a sagittally focusing second crystal will collect most of the photons generated when the chirped electron beam traverses the undulator. A Kirkpatrick-Baez mirror system after the monochromator will deliver to the sample a beam which has an approximately linear correlation between time and vertical beam angle. The correlation at the sample position has a slope of 0.052 ps/?rad extending over an angular range of 800 ?rad for a cavity deflection voltage of 2 MV. The expected time resolution of the whole system is 2.6 ps. The total flux expected at the sample position at 10 keV with a 0.9 eV energy resolution is 5.7 × 10(12) photons/s at a spot having horizontal and vertical full width at half maximum of 33 ?m horizontal by 14 ?m vertical. This new beamline will enable novel time-dispersed diffraction experiments on small samples using the full repetition rate of the APS. PMID:23742528

Reininger, R; Dufresne, E M; Borland, M; Beno, M A; Young, L; Kim, K-J; Evans, P G

2013-05-01

396

Optical design of the short pulse x-ray imaging and microscopy time-angle correlated diffraction beamline at the Advanced Photon Source  

SciTech Connect

The short pulse x-ray imaging and microscopy beamline is one of the two x-ray beamlines that will take full advantage of the short pulse x-ray source in the Advanced Photon Source (APS) upgrade. A horizontally diffracting double crystal monochromator which includes a sagittally focusing second crystal will collect most of the photons generated when the chirped electron beam traverses the undulator. A Kirkpatrick-Baez mirror system after the monochromator will deliver to the sample a beam which has an approximately linear correlation between time and vertical beam angle. The correlation at the sample position has a slope of 0.052 ps/{mu}rad extending over an angular range of 800 {mu}rad for a cavity deflection voltage of 2 MV. The expected time resolution of the whole system is 2.6 ps. The total flux expected at the sample position at 10 keV with a 0.9 eV energy resolution is 5.7 Multiplication-Sign 10{sup 12} photons/s at a spot having horizontal and vertical full width at half maximum of 33 {mu}m horizontal by 14 {mu}m vertical. This new beamline will enable novel time-dispersed diffraction experiments on small samples using the full repetition rate of the APS.

Reininger, R.; Dufresne, E. M.; Borland, M.; Beno, M. A.; Young, L.; Kim, K.-J. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Evans, P. G. [Department of Materials Science and Engineering, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2013-05-15

397

Short Report: Development of a Real-time Quantitative PCR Assay to Enumerate Yersinia pestis in Fleas  

Microsoft Academic Search

A real-time quantitative polymerase chain reaction (qPCR) assay was developed for Yersina pestis. The qPCR assay was developed utilizing a conserved region of the Y. pestis ferric iron uptake regulator gene (fur) to design primers and a fluorescent (FAM-labeled) TaqMan probe. The assay was optimized using cultured Y. pestis (UG05-0454) and was confirmed to work with strains from 3 Y.

Elizabeth S. Gabitzsch; Rommelle Vera-Tudela; Rebecca J. Eisen; Scott W. Bearden; Kenneth L. Gage; Nordin S. Zeidner

2008-01-01

398

Calcination and sintering models for application to high-temperature, short-time sulfation of calcium-based sorbents  

Microsoft Academic Search

To simulate the staged availability of transient high surface area CaO observed in high-temperature flow-reactor data, the paper describes the rate of calcination of CaCOâ or Ca(OH)2, using an empirical modification of the shrinking-core model. The physical model depicts particle decomposition by the shrinking-core mechanism. The subsequent time-dependent decrease in CaO reactivity (surface area and porosity) due to sintering is

Corey R. Milne; Geoffrey D. Silcox; David W. Pershing; David A. Kirchgessner

1990-01-01

399

Time course of lung retention and toxicity of inhaled particles: short-term exposure to nano-Ceria.  

PubMed

Two Ceria nanomaterials (NM-211 and NM-212) were tested for inhalation toxicity and organ burdens in order to design a chronic and carcinogenicity inhalation study (OECD TG No. 453). Rats inhaled aerosol concentrations of 0.5, 5, and 25 mg/m(3) by whole-body exposure for 6 h/day on 5 consecutive days for 1 or 4 weeks with a post-exposure period of 24 or 129 days, respectively. Lungs were examined by bronchoalveolar lavage and histopathology. Inhaled Ceria is deposited in the lung and cleared with a half-time of 40 days; at aerosol concentrations higher than 0.5 mg/m(3), this clearance was impaired resulting in a half-time above 200 days (25 mg/m(3)). After 5 days, Ceria (>0.5 mg/m(3)) induced an early inflammatory reaction by increases of neutrophils in the lung which decreased with time, with sustained exposure, and also after the exposure was terminated (during the post-exposure period). The neutrophil number observed in bronchoalveolar lavage fluid (BALF) was decreasing and supplemented by mononuclear cells, especially macrophages which were visible in histopathology but not in BALF. Further progression to granulomatous inflammation was observed 4 weeks post-exposure. The surface area of the particles provided a dose metrics with the best correlation of the two Ceria's inflammatory responses; hence, the inflammation appears to be directed by the particle surface rather than mass or volume in the lung. Observing the time course of lung burden and inflammation, it appears that the dose rate of particle deposition drove an initial inflammatory reaction by neutrophils. The later phase (after 4 weeks) was dominated by mononuclear cells, especially macrophages. The progression toward the subsequent granulomatous reaction was driven by the duration and amount of the particles in the lung. The further progression of the biological response will be determined in the ongoing long-term study. PMID:25273020

Keller, Jana; Wohlleben, Wendel; Ma-Hock, Lan; Strauss, Volker; Gröters, Sibylle; Küttler, Karin; Wiench, Karin; Herden, Christiane; Oberdörster, Günter; van Ravenzwaay, Bennard; Landsiedel, Robert

2014-11-01

400

The Effects of Timing of Pediatric Knee Ligament Surgery on Short-term Academic Performance in School-Aged Athletes  

Microsoft Academic Search

Background: Orthopaedic injuries negatively affect the academic lives of children.Hypothesis: The timing of anterior cruciate ligament (ACL) and medial patellofemoral ligament (MPFL) reconstructions affects academic performance in school-aged athletes.Study Design: Cohort study; Level of evidence, 2.Methods: Records of patients ?18 years old who underwent ACL or MPFL reconstructions from 2001-2007 were reviewed retrospectively. Subjects had been administered a unique questionnaire

Natasha E. Trentacosta; Mark A. Vitale; Christopher S. Ahmad

2009-01-01

401

1: Know your story. What is the main information you want to tell? In the short time someone stands in  

E-print Network

) or downloaded as a PDF from: http://cis.unh.edu/idc/posters Building Using PowerPoint A Guide for Using PowerPoint categories. Before opening PowerPoint, gather everything you think you want on the poster. This is the time (if room) · 1 table · photo of mountain before NH Sample List: #12;7: Begin. 1) Open PowerPoint (PPT

New Hampshire, University of

402

Predictability of Solar Radiation for Photovoltaics systems over Europe: from short-term to seasonal time-scales  

NASA Astrophysics Data System (ADS)

Photovoltaic diffusion is steadily growing on Europe, passing from a capacity of almost 14 GWp in 2011 to 21.5 GWp in 2012 [1]. Having accurate forecast is needed for planning and operational purposes, with the possibility to model and predict solar variability at different time-scales. This study examines the predictability of daily surface solar radiation comparing ECMWF operational forecasts with CM-SAF satellite measurements on the Meteosat (MSG) full disk domain. Operational forecasts used are the IFS system up to 10 days and the System4 seasonal forecast up to three months. Forecast are analysed considering average and variance of errors, showing error maps and average on specific domains with respect to prediction lead times. In all the cases, forecasts are compared with predictions obtained using persistence and state-of-art time-series models. We can observe a wide range of errors, with the performance of forecasts dramatically affected by orography and season. Lower errors are on southern Italy and Spain, with errors on some areas consistently under 10% up to ten days during summer (JJA). Finally, we conclude the study with some insight on how to "translate" the error on solar radiation to error on solar power production using available production data from solar power plants. [1] EurObserver, "Baromètre Photovoltaïque, Le journal des énergies renouvables, April 2012."

De Felice, Matteo; Petitta, Marcello; Ruti, Paolo

2014-05-01

403

Demospongic Acids Revisited  

PubMed Central

The well-known fatty acids with a ?5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32) and from some terrestrial plants with short acyl chains (C18–C19). Finally, the ?5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between ?5,9 fatty acids and other NMI FAs. PMID:21116406

Kornprobst, Jean-Michel; Barnathan, Gilles

2010-01-01

404

Very short NMR relaxation times of anions in ionic liquids: New pulse sequence to eliminate the acoustic ringing  

NASA Astrophysics Data System (ADS)

NMR relaxation processes of anions were studied in two neat imidazolium-based room temperature ionic liquids (RTILs) 1-decyl-3-methyl-imidazolium bromide- and chloride. The spin-lattice and spin-spin relaxations of 81Br and 35Cl nuclei were found to be extremely fast due to very strong quadrupolar interactions. The determined relaxation rates are comparable with those observed in the solids or in some critical organic solute/water/salt systems. In order to eliminate the acoustic ringing of the probe-head during relaxation times measurements the novel pulse sequence has been devised. It is based on the conventional inversion recovery pulse sequence, however, instead of the last 90° pulse the subsequence of three 90° pulses applied along axes to fulfill the phase cycling condition is used. Using this pulse sequence it was possible to measure T1 for both studied nuclei. The viscosity measurements have been carried out and the rotational correlation times were calculated. The effective 35Cl quadrupolar coupling constant was found to be almost one order lower than that for 81Br, i.e. 1.8 MHz and 16.0 MHz, respectively. Taking into account the facts that the ratio of (Q(35Cl)/Q(81Br))2 ? 0.1 and EFG tensors on the anions are quite similar, analogous structural organizations are expected for both RTILs. The observed T1/T2 (1.27-1.44) ratios were found to be not sufficiently high to confirm the presence of long-living (on the time scale of ?10-8 s) mesoscopic structures or heterogeneities in the studied neat ionic liquids.

Klimavicius, Vytautas; Gdaniec, Zofia; Balevicius, Vytautas

2014-11-01

405

Short time scales of magma-mixing processes prior to the 2011 eruption of Shinmoedake volcano, Kirishima volcanic group, Japan  

NASA Astrophysics Data System (ADS)

We estimated time scales of magma-mixing processes just prior to the 2011 sub-Plinian eruptions of Shinmoedake volcano to investigate the mechanisms of the triggering processes of these eruptions. The sequence of these eruptions serves as an ideal example to investigate eruption mechanisms because the available geophysical and petrological observations can be combined for interpretation of magmatic processes. The eruptive products were mainly phenocryst-rich (28 vol%) andesitic pumice (SiO2 57 wt%) with a small amount of more silicic pumice (SiO2 62-63 wt%) and banded pumice. These pumices were formed by mixing of low-temperature mushy silicic magma (dacite) and high-temperature mafic magma (basalt or basaltic andesite). We calculated the time scales on the basis of zoning analysis of magnetite phenocrysts and diffusion calculations, and we compared the derived time scales with those of volcanic inflation/deflation observations. The magnetite data revealed that a significant mixing process (mixing I) occurred 0.4 to 3 days before the eruptions (pre-eruptive mixing) and likely triggered the eruptions. This mixing process was not accompanied by significant crustal deformation, indicating that the process was not accompanied by a significant change in volume of the magma chamber. We propose magmatic overturn or melt accumulation within the magma chamber as a possible process. A subordinate mixing process (mixing II) also occurred only several hours before the eruptions, likely during magma ascent (syn-eruptive mixing). However, we interpret mafic injection to have begun more than several tens of days prior to mixing I, likely occurring with the beginning of the inflation (December 2009). The injection did not instantaneously cause an eruption but could have resulted in stable stratified magma layers to form a hybrid andesitic magma (mobile layer). This hybrid andesite then formed the main eruptive component of the 2011 eruptions of Shinmoedake.

Tomiya, Akihiko; Miyagi, Isoji; Saito, Genji; Geshi, Nobuo

2013-10-01

406

Recurrence plots revisited  

Microsoft Academic Search

We show that recurrence plots (RPs) give detailed characterizations of time series generated by dynamical systems driven by slowly varying external forces. For deterministic systems we show that RPs of the time series can be used to reconstruct the RP of the driving force if it varies sufficiently slowly. If the driving force is one-dimensional, its functional form can then

M. C. Casdagli

1997-01-01

407

Interaction between workers during a short time window is required for bacterial symbiont transmission in Acromyrmex leaf-cutting ants.  

PubMed

Stable associations between partners over time are critical for the evolution of mutualism. Hosts employ a variety of mechanisms to maintain specificity with bacterial associates. Acromyrmex leaf-cutting ants farm a fungal cultivar as their primary nutrient source. These ants also carry a Pseudonocardia Actinobacteria exosymbiont on their bodies that produces antifungal compounds that help inhibit specialized parasites of the ants' fungal garden. Major workers emerge from their pupal cases (eclose) symbiont-free, but exhibit visible Actinobacterial coverage within 14 days post-eclosion. Using subcolony experiments, we investigate exosymbiont transmission within Acromyrmex colonies. We found successful transmission to newly eclosed major workers fostered by major workers with visible Actinobacteria in all cases (100% acquiring, n?=?19). In contrast, newly eclosed major workers reared without exosymbiont-carrying major workers did not acquire visible Actinobacteria (0% acquiring, n?=?73). We further show that the majority of ants exposed to major workers with exosymbionts within 2 hours of eclosion acquired bacteria (60.7% acquiring, n?=?28), while normal acquisition did not occur when exposure occurred later than 2 hours post-eclosion (0% acquiring, n?=?18). Our findings show that transmission of exosymbionts to newly eclosed major workers occurs through interactions with exosymbiont-covered workers within a narrow time window after eclosion. This mode of transmission likely helps ensure the defensive function within colonies, as well as specificity and partner fidelity in the ant-bacterium association. PMID:25058579

Marsh, Sarah E; Poulsen, Michael; Pinto-Tomás, Adrián; Currie, Cameron R

2014-01-01

408

Plasma and Fusion Research: Regular Articles Vol. 4 (2009) Adiabatic Wave-Particle Interaction Revisited  

E-print Network

Revisited Robert L. DEWAR1,2) and Justin C.-C. YAP1) 1) Plasma Research Laboratory and Dept. of Theoretical that the wave frame is noninertial if is author's e-mail: robert.dewar@anu.edu.au time-dependent.) The equation

Dewar, Robert L.

409

Modular Ontology Languages Revisited Bernardo Cuenca-Grau and Oliver Kutz  

E-print Network

be processed, it may still be the case that the processing time involved is too high for ontology engineering in order to assist the ontology engineer in performing these tasks. We distinguish two ap- proachesModular Ontology Languages Revisited Bernardo Cuenca-Grau and Oliver Kutz The University

Grau, Bernardo Cuenca

410

The short-time structural plasticity of dendritic spines is altered in a model of Rett syndrome  

PubMed Central

The maturation of excitatory transmission comes about through a developmental period in which dendritic spines are highly motile and their number, form and size are rapidly changing. Surprisingly, although these processes are crucial for the formation of cortical circuitry, little is known about possible alterations of these processes in brain disease. By means of acute in vivo 2-photon imaging we show that the dynamic properties of dendritic spines of layer V cortical neurons are deeply affected in a mouse model of Rett syndrome (RTT) at a time around P25 when the neuronal phenotype of the disease is still mild. Then, we show that 24h after a subcutaneous injection of IGF-1 spine dynamics is restored. Our study demonstrates that spine dynamics in RTT mice is severely impaired early during development and suggest that treatments for RTT should be started very early in order to reestablish a normal period of spine plasticity. PMID:22355564

Landi, Silvia; Putignano, Elena; Boggio, Elena Maria; Giustetto, Maurizio; Pizzorusso, Tommaso; Ratto, Gian Michele

2011-01-01

411

Promoting healthy timing and spacing of pregnancy with young married women in Northern Nigeria: a short report.  

PubMed

The persistence of early and closely spaced pregnancies in Northern Nigeria contributes to maternal and child morbidity and mortality. A technical working group to WHO recommended that following a birth, a woman should space her next pregnancy by at least 24 months, and following a miscarriage or abortion, a woman space her next pregnancy by at least six months. UNICEF, UNFPA and WHO also recommend that a woman delay her first pregnancy until 18. These recommendations comprise the concept of Healthy Timing and Spacing of Pregnancy. The Extending Service Delivery Project (ESD) partnered with the Federation of Muslim Women Association of Nigeria and religious leaders to educate communities about the benefits of using family planning to practice HTSP in five local government areas. Informal discussions with 148 women and 28 men found high recall of the HTSP recommendations and favorable attitudes toward spacing and family planning although many remain concerned about the side effects of contraceptive methods. PMID:22916558

Lane, Cate; Joof, Yaikah M; Hassan, Aisha Ahmed; Pryor, Shannon

2012-06-01

412

Late Devonian paleomagnetism of the North Tien Shan, Kyrgyzia: can secular variation vary on a short time scale?  

NASA Astrophysics Data System (ADS)

We studied more than eighty lava flows from a ca. 600-meter thick pile of Upper Devonian (Frasnian) basalts and andesites of the Aral Formation in the North Tien Shan (Kyrgyzia, Central Asia). With the aid of stepwise thermal demagnetization, a high-temperature dual-polarity component was reliably isolated from most flows. The primary origin of the high-temperature component is demonstrated by positive reversal, conglomerate and fold tests. The most prominent and intriguing feature of this Late Devonian dataset involves a clear distinction in angular dispersion between the lower and upper parts of the studied section. A rather low concentration parameter (k = 14) and several directional anomalies characterize the lower section; in contrast, a much better grouping (k = 46) and a lack of directional outliers is observed for the dual-polarity vectors from the upper flow-sequence of the formation. Unable to find any rock magnetic difference between upper and lower flow sequences, we favor a geomagnetic origin for this difference and advocate the hypothesis that the magnitude of secular variation can randomly vary several-fold at the same paleolatitude and over time intervals estimated as 100,000-1,000,000 y. This is in sharp contrast with other models of secular variation, where this magnitude has been assumed to be rather time-independent (for a given latitude). Our hypothesis accounts for the observed irregularities in paleomagnetic data but makes attempts to establish a correlation between secular variation and other parameters (geographic latitude, reversal frequency, age, etc.) more difficult or even rather futile.

Bazhenov, M. L.; Van Der Voo, R.; Levashova, N. M.; Dominguez, A. R.

2011-12-01

413

The parallel-antiparallel signal difference in double-wave-vector diffusion-weighted MR at short mixing times: A phase evolution perspective  

NASA Astrophysics Data System (ADS)

Experiments with two diffusion weightings applied in direct succession in a single acquisition, so-called double- or two-wave-vector diffusion-weighting (DWV) experiments at short mixing times, have been shown to be a promising tool to estimate cell or compartment sizes, e.g. in living tissue. The basic theory for such experiments predicts that the signal decays for parallel and antiparallel wave vector orientations differ by a factor of three for small wave vectors. This seems to be surprising because in standard, single-wave-vector experiments the polarity of the diffusion weighting has no influence on the signal attenuation. Thus, the question how this difference can be understood more pictorially is often raised. In this rather educational manuscript, the phase evolution during a DWV experiment for simple geometries, e.g. diffusion between parallel, impermeable planes oriented perpendicular to the wave vectors, is considered step-by-step and demonstrates how the signal difference develops. Considering the populations of the phase distributions obtained, the factor of three between the signal decays which is predicted by the theory can be reproduced. Furthermore, the intermediate signal decay for orthogonal wave vector orientations can be derived when investigating diffusion in a box. Thus, the presented “phase gymnastics” approach may help to understand the signal modulation observed in DWV experiments at short mixing times.

Finsterbusch, Jürgen

2011-01-01

414

Short-time Fourier transform analysis of ab initio molecular dynamics simulation: collision reaction between CN and C4H6.  

PubMed

Collision reactions between cyano radical (CN) and dimethylacetylene (C4H6) are thought to occur in the atmosphere of Saturn's moon Titan. However, it is difficult to reproduce reactions occurring in unique environments to study their dynamical processes. In this study, collision reactions between CN and C4H6 were investigated using ab initio molecular dynamics (AIMD) simulations. The simulation results were categorized into three kinds: nonreactive collision, incorporation, and substitution. Short-time Fourier transform analysis of velocity autocorrelation functions obtained by the AIMD simulations, which has been recently developed by our research group, was performed to examine the nonequilibrium condition of the vibrational states. Spectrograms, which correspond to the time evolution of power spectra, clarify the relationship between the three reaction channels and the dynamical changes of the vibrational states. PMID:15688439

Tamaoki, Mari; Yamauchi, Yusuke; Nakai, Hiromi

2005-04-15

415

Comparison of MCNP calculation and measurement of neutron fluence in a channel for short-time irradiation in the LVR-15 reactor  

SciTech Connect

The main purpose of this work was to evaluate the neutron energy distribution in a channel of the LVR-15 reactor used mostly for short-time neutron activation analysis. Twenty types of activation monitors were irradiated in this channel equipped with a pneumatic facility with a transport time of 3.5 s. The activities measured and the corresponding reaction rates were used to determinate the neutron spectrum. The reaction rates were compared with MCNP calculations to confirm the results. The second purpose of this work was to verify our nuclear data library used for the reaction rate calculations. The experiment results were also incorporated into our database system of neutron energy distribution at the reactor core. (authors)

Lahodova, Z.; Flibor, S.; Klupak, V. [Nuclear Research Inst. Rez Plc, Reactor Services Div., 250 68 Rez (Czech Republic); Kucera, J. [Nuclear Physics Inst., Academy of Science of the Czech Republic, 250 68 Rez (Czech Republic); Marek, M.; Viererbl, L. [Nuclear Research Inst. Rez Plc, Reactor Services Div., 250 68 Rez (Czech Republic)

2006-07-01

416

Time-frequency analysis of short-lasting modulation of EEG induced by TMS during wake, sleep deprivation and sleep  

PubMed Central

The occurrence of dynamic changes in spontaneous electroencephalogram (EEG) rhythms in the awake state or sleep is highly variable. These rhythms can be externally modulated during transcranial magnetic stimulation (TMS) with a perturbation method to trigger oscillatory brain activity. EEG-TMS co-registration was performed during standard wake, during wake after sleep deprivation and in sleep in six healthy subjects. Dynamic changes in the regional neural oscillatory activity of the cortical areas were characterized using time-frequency analysis based on the wavelet method, and the modulation of induced oscillations were related to different vigilance states. A reciprocal synchronizing/desynchronizing effect on slow and fast oscillatory activity was observed in response to focal TMS after sleep deprivation and sleep. We observed a sleep-related slight desynchronization of alpha mainly over the frontal areas, and a widespread increase in theta synchronization. These findings could be interpreted as proof of the interference external brain stimulation can exert on the cortex, and how this could be modulated by the vigilance state. Potential clinical applications may include evaluation of hyperexcitable states such as epilepsy or disturbed states of consciousness such as minimal consciousness. PMID:24302903

Manganotti, Paolo; Formaggio, Emanuela; Del Felice, Alessandra; Storti, Silvia F.; Zamboni, Alessandro; Bertoldo, Alessandra; Fiaschi, Antonio; Toffolo, Gianna M.

2013-01-01

417

Short communication: Added value of rumination time for the prediction of dry matter intake in lactating dairy cows.  

PubMed

The objective of the current study was to quantify the change in the prediction of dry matter intake (DMI) resulting from the inclusion of rumination time (RT) in the 2001 National Research Council (NRC) DMI prediction model. Forty-one Holstein cows fed the same total mixed ration were involved in a 10-wk study. Individual DMI were measured daily. The accuracy and precision of the original NRC prediction model, based on body weight, fat-corrected milk, and week of lactation as independent variables, was compared with the accuracy and precision of the same model with RT as an additional independent variable. The RT estimate was significant in the model developed but had a low value (0.031 kg/h). Root mean square prediction errors were very similar in the 2 models (1.70 and 1.68 kg/d) as were the other indicators (R(2), linear bias, random error, and concordance correlation coefficient) selected to compare the models in this study. These results indicate no gain in DMI prediction precision or accuracy when RT is included in the NRC model. PMID:25129493

Clément, P; Guatteo, R; Delaby, L; Rouillé, B; Chanvallon, A; Philipot, J M; Bareille, N

2014-10-01

418

Time-resolved synchrotron diffraction and theoretical studies of very short-lived photo-induced molecular species  

PubMed Central

Definitive experimental results on the geometry of fleeting species are at the time of writing still limited to monochromatic data collection, but methods for modifications of the polychromatic Laue data to increase their accuracy and their suitability for pump–probe experiments have been implemented and are reviewed. In the monochromatic experiments summarized, excited-state conversion percentages are small when neat crystals are used, but are higher when photoactive species are embedded in an inert framework in supramolecular crystals. With polychromatic techniques and increasing source brightness, smaller samples down to tenths of a micrometre or less can be used, increasing homogeneity of exposure and the fractional population of the excited species. Experiments described include a series of transition metal complexes and a fully organic example involving excimer formation. In the final section, experimental findings are compared with those from theoretical calculations on the isolated species. Qualitative agreement is generally obtained, but the theoretical results are strongly dependent on the details of the calculation, indicating the need for further systematic analysis. PMID:20164641

Coppens, Philip; Benedict, Jason; Messerschmidt, Marc; Novozhilova, Irina; Graber, Tim; Chen, Yu-Sheng; Vorontsov, Ivan; Scheins, Stephan; Zheng, Shao-Liang

2010-01-01

419

Time-resolved synchrotron diffraction and theoretical studies of very short-lived photo-induced molecular species.  

PubMed

Definitive experimental results on the geometry of fleeting species are at the time of writing still limited to monochromatic data collection, but methods for modifications of the polychromatic Laue data to increase their accuracy and their suitability for pump-probe experiments have been implemented and are reviewed. In the monochromatic experiments summarized, excited-state conversion percentages are small when neat crystals are used, but are higher when photoactive species are embedded in an inert framework in supramolecular crystals. With polychromatic techniques and increasing source brightness, smaller samples down to tenths of a micrometre or less can be used, increasing homogeneity of exposure and the fractional population of the excited species. Experiments described include a series of transition metal complexes and a fully organic example involving excimer formation. In the final section, experimental findings are compared with those from theoretical calculations on the isolated species. Qualitative agreement is generally obtained, but the theoretical results are strongly dependent on the details of the calculation, indicating the need for further systematic analysis. PMID:20164641

Coppens, Philip; Benedict, Jason; Messerschmidt, Marc; Novozhilova, Irina; Graber, Tim; Chen, Yu-Sheng; Vorontsov, Ivan; Scheins, Stephan; Zheng, Shao-Liang

2010-03-01

420

Catalyst assessment for upgrading short contact time SRC (solvent-refined coal) to low-sulfur boiler fuels  

SciTech Connect

Of nine catalysts tested in a fixed-bed pilot unit for upgrading a 50% West Kentucky SRC recycle solvent blend, best desulfurization and deoxygenation activities were obtained with proprietary catalysts, Mobil HCL-2 and HCL-3, American Cyanamid's commercial HDS-1443, and Harshaw's commercial 618X catalyst. The activities depended in part on the presence of macropores. The best Conradson carbon residue reduction was obtained with Mobil HCL-2 and HCL-3, and with Amoco'/s developmental catalyst Amocat 1B. The highest polar asphaltene conversion was obtained with Amocat 1B and HDS-1443. The lowest hydrogen consumption as a function of total liquid product sulfur content occurred with HCL-2, HDS-1443, and Amocat 1A. An aging run with Amocat 1A was operated smoothly for 15 days at 2000 psig and 775/sup 0/F, and then terminated owing to incipient reactor plugging; a simple deactivation equation correctly predicted the degree of desulfurization with time on stream, which was equivalent to a 2/sup 0/ to 3/sup 0/F/day temperature rise for maintaining constant product sulfur levels. The deposits formed on the catalysts were analyzed.

Shih, S.S.; Angevine, P.J.; Heck, R.H.; Sawruk, S.

1980-01-01

421

Use of high-concentration-short-time chlorine dioxide gas treatments for the inactivation of Salmonella enterica spp. inoculated onto Roma tomatoes.  

PubMed

Salmonella outbreaks have been recently linked to the consumption of fresh tomatoes. Thus, there is a need to develop systems that reduce the risk of microbial contamination to increase product shelf-life and keep fresh fruit attributes. The objectives of this study were to evaluate high-concentration-short-time chlorine dioxide gas treatments effects on Salmonella-inoculated Roma tomatoes and determine the optimal treatment conditions for microbial inactivation and shelf-life extension. Effects of ClO(2) concentration (2, 5, 8 and 10mg/l) and exposure time (10, 30, 60, 120 and 180 s) on inoculated Roma tomatoes were studied. Salmonella enterica strains, serotype Montevideo, Javiana and Baildon, were used to experimentally inoculate the food product. After ClO(2) treatments, tomatoes were stored at room temperature for 28 days. Inherent microbial population, change in tomato color, and chlorine dioxide gas residuals were evaluated. ANOVA analysis showed that both ClO(2) concentration and treatment time were significant (p<0.01) for Salmonella inactivation. Surviving Salmonella populations of 3.09, 2.17 and 1.16 logCFU/cm(2) were obtained treating tomatoes with 8 mg/l ClO(2) for 60 s, 10 mg/l ClO(2) for 120 s, and 10 mg/l for 180 s, respectively (initial Salmonella population: 6.03±0.11 log CFU/cm(2)). The selected treatments significantly reduced background microflora (p<0.05), while fruit color and residual contents were not significantly different (p>0.05), as compared to the control. Results suggest the potential for high-concentration-short-time treatments ClO(2) gas as an effective pathogen inactivation technology for large-scale produce packing operations. PMID:20832678

Trinetta, V; Morgan, M T; Linton, R H

2010-12-01

422

Time-dependent Changes of Cadmium and Metallothionein after Short-term Exposure to Cadmium in Rats  

PubMed Central

The time-dependent changes in cadmium (Cd) concentration were studied in Female Sprague-Dawley (SD) rats during and after Cd exposure via drinking water (10 and 50 ppm) for 30 days. The cadmium concentration in muscle, liver, kidney, blood plasma, and urine, and the metallothionein concentration in blood plasma were determined every 10 days during exposure and every 7 days after exposure for 3 weeks. The muscle Cd concentration did not change during, and neither after, exposure. The liver Cd concentration increased from 1.4 to 3.3 (at 10 ppm) and from 6.1 to 10.1 folds (at 50 ppm) during exposure and remained higher than those of controls in both groups even during post-exposure period. The kidney Cd concentrations were 2.3 to 5.1 (at 10 ppm) and 4.9-14.0 folds (at 50 ppm) higher than those of controls during exposure and also remained elevated during the post-exposure period. Plasma Cd concentrations were not significantly different from those of controls in both groups. Urine Cd concentrations were more than 2 folds (at 10 ppm) and 6.5 to 12.6 folds (at 50 ppm) higher than those of controls but rapidly decreased over the 7 days of withdrawal. Blood plasma metallothionein concentrations were more than 2.4 folds (at 10 ppm) and 3.1 to 7.4 folds (at 50 ppm) , and they remained elevated till 7 days (10 ppm) and 14 days (at 50 ppm) after exposure. Our data support that Cd in urine could be a useful biomarker during Cd exposure period and metallothionein in blood plasma could be as a supportive biological marker for during and post Cd exposure. PMID:24278516

Cho, Mi Ran; Jeong, Sang-Hee; Cho, Myung Haing

2010-01-01

423

Temporal compositional trends over short and long time-scales in basalts of the Big Pine Volcanic Field, California  

NASA Astrophysics Data System (ADS)

Primitive basaltic single eruptions in the Big Pine Volcanic Field (BPVF) of Owens Valley, California show systematic temporal-compositional variation that cannot be described by simple models of fractional crystallization, partial melting of a single source, or crustal contamination. We targeted five monogenetic eruption sequences in the BPVF for detailed chemical and isotopic measurements and 40Ar/ 39Ar dating, focusing primarily on the Papoose Canyon sequence. The vent of the primitive (Mg# = 69) Papoose Canyon sequence (760.8 ± 22.8 ka) produced magmas with systematically decreasing (up to a factor of two) incompatible element concentrations, at roughly constant MgO (9.8 ± 0.3 (1?) wt.%) and Na 2O. SiO 2 and compatible elements (Cr and Ni) show systematic increases, while 87Sr/ 86Sr systematically decreases (0.7063-0.7055) and ? Nd increases (- 3.4 to - 1.1). 187Os/ 188Os is highly radiogenic (0.20-0.31), but variations among four samples do not correlate with other chemical or isotopic indices, are not systematic with respect to eruption order, and thus the Os system appears to be decoupled from the dominant trends. The single eruption trends likely result from coupled melting and mixing of two isotopically distinct sources, either through melt-rock interaction or melting of a lithologically heterogeneous source. The other four sequences, Jalopy Cone (469.4 ± 9.2 ka), Quarry Cone (90.5 ±17.6 ka), Volcanic Bomb Cone (61.6 ± 23.4 ka), and Goodale Bee Cone (31.8 ± 12.1 ka) show similar systematic temporal decreases in incompatible elements. Monogenetic volcanic fields are often used to decipher tectonic changes on the order of 10 5-10 6 yr through long-term changes in lava chemistry. However, the systematic variation found in Papoose Canyon (10 0-10 2 yr) nearly spans that of the entire volcanic field, and straddles cutoffs for models of changing tectonic regime over much longer time-scales. Moreover, ten new 40Ar/ 39Ar ages combined with chemistry from all BPVF single eruption sequences show the long-term trend of BPVF evolution comprises the overlapping, temporal-compositional trends of the monogenetic vents. This suggests that the single eruption sequences contain the bulk of the systematic chemical variation, whereas their aggregate compositions define the long-term trend of volcanic field evolution.

Blondes, Madalyn S.; Reiners, Peter W.; Ducea, Mihai N.; Singer, Brad S.; Chesley, John

2008-05-01

424

Adaptive Individual Differences Revisited  

Microsoft Academic Search

Humans possess a complex array of evolved psychological mechanisms, only a subset of which is activated at any particular time. Attempts to reduce human sexual strategies to a single, rigid, invariant strategy, and to label departures from a single strategy as maladjusted, fail to accord with a large body of empirical evidence. Personality psychology cannot afford to ignore the rich

David M. Buss

1999-01-01

425

The plasmapause revisited  

NASA Technical Reports Server (NTRS)

Saturation of the dc double probe instrument on Explorer 45 was used to identify the plasmapause. A data base was developed to statistically study the average position of the plasmapause over 14.5 hours of magnetic local time under differing magnetic conditions. The afternoon-evening bulge in the L coordinate of the plasmapause versus local time was found centered between 20 and 21 hours MLT during magnetically quiet periods and shifted toward dusk as activity increased, but always post dusk. During quiet periods a bulge in the L coordinate near noon was also seen, which disappeared as activity increased. The average local time distribution plasmapause position during high magnetic activity was irregular in the afternoon region where large scale convection models predict the creation of plasmatails or detached plasma regions from increases in the solar wind induced convection. The results suggest that solar wind induced convection is partially shielded from the dayside. As the intensity of the convection is increased, it more effectively penetrates the dayside, which shifts the post dusk bulge nearer to dusk and eliminates the quiet-time bulge near noon.

Maynard, N. C.; Gebowsky, J. M.

1976-01-01

426

Dissipative Particle Dynamics revisited  

Microsoft Academic Search

Dissipative Particle Dynamics is a particle model that allows to simulate complex fluids at meso- scopic scales. Since its introduction a decade ago it has been applied to a large variety of different complex fluid systems. At the same time, generalizations of the model have been introduced in order to refine the concept of dissipative particle. Here, I offer my

Pep Espa

427

Green Science: Revisiting Recycling  

ERIC Educational Resources Information Center

Recycling has been around for a long time--people have reused materials and refashioned them into needed items for thousands of years. More recently, war efforts encouraged conservation and reuse of materials, and in the 1970s recycling got its official start when recycling centers were created. Now, curbside recycling programs and recycling…

Palliser, Janna

2011-01-01

428

Revisiting High School Visits  

ERIC Educational Resources Information Center

NACAC's anniversary is a great time to follow up on an article on high school visits, a topic of ongoing discussion in every admission and guidance office. The article highlights a variety of potential good outcomes that can be derived from collaborative interactions. Sadly, however, admission representatives are apt to be described by the…

Flagel, Andrew

2012-01-01

429

Effects of high pressure homogenisation of raw bovine milk on alkaline phosphatase and microbial inactivation. A comparison with continuous short-time thermal treatments.  

PubMed

Raw whole milk of high microbial quality (58 degrees C), but markedly decreased above 200 MPa when Tin=24 degrees C (T2>60 degrees C). In contrast to inactivation induced by continuous short-time thermal treatments, ALP inactivation induced by HP homogenisation was clearly due to mechanical forces (shear, cavitation and/or impact) in the HP valve and not to the short (<1 s) residence time at temperature T2 in the same valve. Inactivation of the three exogenous microorganisms led to similar conclusions. Homogenisation at 250 MPa or 300 MPa (Tin=24 degrees C) induced a 2-3 log cycle reduction of the total endogenous milk flora and a 1.5-1.8 log cycle reduction of inoculated List. innocua. Higher reduction ratios (2-4 log cycles) were obtained for the two other microorganisms. The highest levels of ALP inactivation corresponded to the highest extents of microbial reduction. Running the milk twice or three times through the homogeniser (recycling), keeping temperature T1 approximately 29 degrees C and pressure=200 MPa, increased homogenisation efficiency. PMID:16834813

Picart, Laëtitia; Thiebaud, Maryse; René, Malika; Pierre Guiraud, Joseph; Cheftel, Jean Claude; Dumay, Eliane

2006-11-01

430

Episodicity of Orogeny Revisited  

NASA Astrophysics Data System (ADS)

Although it is well established that orogeny is episodic, the duration, correlation and geographic distribution of orogenic episodes is not well constrained. Using large numbers of concordant U/Pb zircon ages from subduction-related granitoids (> 7000), it is now possible to better constrain these variables. Monte Carlo simulation probabilistic histograms of zircon age spectra remove questionable and spurious age peaks, yet allow resolution of peaks with >10 My duration with the data sets. Orogenic episodes with durations < 20 My, herein called pulses, are generally of regional geographic extent, whereas long-lived events (100-250 My), herein called periods, may be of regional or global extent. Orogenic periods comprise several to many pulses. Most orogenic pulses reflect geographic variations in intensity of subduction or/and plate collisions as for instance recorded around the perimeter of the Pacific basin in the last 100 My. Neither of the widely recognized pulses at 2.7 nor 1.9 Ga is global in extent. Orogenic pulses at 2700 and 2680 Ma occur on four continents each (2700: Superior, Hearne-Rae, Nain, North China; 2680: Yilgarn, Africa, Slave, Wyoming). Likewise, an orogenic pulse at 1880 is found on four continents (Laurentia, Baltica, East Asia, South America), and another pulse at 1860 Ma occurs on three continents (Africa, Siberia, Australia). Some orogenic pulses track lateral continental growth, such as 2730, 2715, and 2700 Ma pulses in the Abitibi greenstone belt, and 850, 800 and 750 Ma pulses in the Arabian-Nubian shield. Major orogenic periods are recognized at 2750-2650, 1900-1650, and 1250-1000 Ma and each of these is associated with supercontinent formation. Orogenic periods at 2600-2500 (China and India) and 2150-2050 Ma (West Africa, Amazonia, Rio de la Plata) may be associated with the formation of small supercontinents. Our results suggest that orogenic periods with intervening gaps may not require sudden and short-lived changes in mantle behavior, but may be associated primarily with the supercontinent cycle, and thus be a characteristic feature of planets with plate tectonics.

Condie, K. C.; Aster, R. C.

2008-12-01

431

Counting glycans revisited.  

PubMed

We present an algorithm for counting glycan topologies of order [Formula: see text] that improves on previously described algorithms by a factor [Formula: see text] in both time and space. More generally, we provide such an algorithm for counting rooted or unrooted [Formula: see text]-ary trees with labels or masses assigned to the vertices, and we give a "recipe" to estimate the asymptotic growth of the resulting sequences. We provide constants for the asymptotic growth of [Formula: see text]-ary trees and labeled quaternary trees (glycan topologies). Finally, we show how a classical result from enumeration theory can be used to count glycan structures where edges are labeled by bond types. Our method also improves time bounds for counting alkanes. PMID:23974240

Böcker, Sebastian; Wagner, Stephan

2014-10-01

432

Operational Near Real-Time Derivation of Land Surface Albedo and Down-Welling Short-Wave Radiation from MSG Observations  

NASA Astrophysics Data System (ADS)

In the framework of the EUMETSAT Satellite Applica- tion Facility for Land Surface Analysis (Land-SAF) we develop surface albedo and short-wave radiation products which will be generated in near real-time from observa- tions provided by the MSG/SEVIRI instrument. The albedo algorithm exploits the diurnal variation of the illumination angle, which provides information on the angular variation of reflectance, in order to invert a lin- ear kernel-based bi-directional reflectance model. Sev- eral albedo variants are derived by adequately integrating the constrained model functions. In the case of poor an- gular sampling the achievable accuracy needs to be aug- mented by additional information, e.g. by using a static a priori information data base derived from measurements of instruments with multiple view angle capabilities. The down-welling short-wave radiation at the surface es- sentially depends on cloud cover and hence to derive a reliable estimate of this quantity the cloud mask repre- sents an important piece of information. Depending on the presence of clouds and potentially on cloud type dif- ferent physically based parameterisation schemes are ap- plied to approximate the radiative transfer problem. Key words: Meteosat Second Generation; Land Surface Albedo; Down-welling Radiation.

Geiger, B.; Franchistéguy, L.; Lajas, D.; Roujean, J.-L.

2004-11-01

433

Dimensional analysis revisited.  

PubMed

The applicability of dimensional analysis (DA) is discussed in relation to the metabolic scaling laws. The evolution of different theories of biological similarity has shown that the calculated reduced exponents (b) of Huxley's allometric equation are closely correlated with the numerical values obtained from the statistical analysis of empirical data. Body mass and body weight are not equivalent as biological reference systems, since in accordance to Newton's second law, the former has a dimension of a mass, while the latter should be dimensionally considered as a force (W = MLT-2). This distinction affects the coefficients of the mass exponent (alpha). This difference is of paramount importance in microgravity conditions (spaceflight) and of buoyancy during the fetal life in mammals. Furthermore, the coefficients (beta) of the length dimension, and (gamma) of the time dimension do not vary when mass or weight are utilized as reference systems. Consequently, the "specific metabolic time," that results from the ratio of basal oxygen consumption and body mass or body weight yields the "biological meaning" of the time dimension, which is of fractal nature. PMID:14631872

Günther, Bruno; Morgado, Enrique

2003-01-01

434

Health risk of chrysotile revisited  

PubMed Central

This review provides a basis for substantiating both kinetically and pathologically the differences between chrysotile and amphibole asbestos. Chrysotile, which is rapidly attacked by the acid environment of the macrophage, falls apart in the lung into short fibers and particles, while the amphibole asbestos persist creating a response to the fibrous structure of this mineral. Inhalation toxicity studies of chrysotile at non-lung overload conditions demonstrate that the long (>20?µm) fibers are rapidly cleared from the lung, are not translocated to the pleural cavity and do not initiate fibrogenic response. In contrast, long amphibole asbestos fibers persist, are quickly (within 7?d) translocated to the pleural cavity and result in interstitial fibrosis and pleural inflammation. Quantitative reviews of epidemiological studies of mineral fibers have determined the potency of chrysotile and amphibole asbestos for causing lung cancer and mesothelioma in relation to fiber type and have also differentiated between these two minerals. These studies have been reviewed in light of the frequent use of amphibole asbestos. As with other respirable particulates, there is evidence that heavy and prolonged exposure to chrysotile can produce lung cancer. The importance of the present and other similar reviews is that the studies they report show that low exposures to chrysotile do not present a detectable risk to health. Since total dose over time decides the likelihood of disease occurrence and progression, they also suggest that the risk of an adverse outcome may be low with even high exposures experienced over a short duration. PMID:23346982

Dunnigan, Jacques; Hesterberg, Thomas; Brown, Robert; Velasco, Juan Antonio Legaspi; Barrera, Raul; Hoskins, John; Gibbs, Allen

2013-01-01