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Sample records for transit time measurement

  1. Transit time measurement of Juqueri river waters

    International Nuclear Information System (INIS)

    Plata Bedmar, E.; Garcia A, E.; Albuquerque, A.M. de; Sanchez, W.

    1975-01-01

    The time of travel of the Juqueri River water through the east branch of the Pirapora Reservoir was measured using radioactive tracers (6 Ci 131 I in Kl Solution). The changes in Juqueri River flow rate were also measured during the run. The center of mass of the radioactive cloud was used for the time of travel calculations. Six measurements of the Juqueri River flow rate were perfomed in different days, using the total count method. Fifty, millicuries of 131 I were used in each run. The results of time travel obtained under non-steady conditions, and their correction for steady state are also discussed

  2. Chronopotentiometric chloride sensing using transition time measurement

    NARCIS (Netherlands)

    Abbas, Yawar; de Graaf, D.B.; Olthuis, Wouter; van den Berg, Albert

    2013-01-01

    Detection of chloride ions is crucial to accurately access the concrete structure durability[1]. The existing electrochemical method of chloride ions detection in concrete, potentiometry[1], is not suitable for in-situ measurement due to the long term stability issue of conventional reference

  3. Simplified scintigraphic methods for measuring gastrointestinal transit times

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2000-01-01

    To investigate whether simple transit measurements based on scintigraphy performed only 0, 2, 4 and 24 h after intake of a radiolabelled meal can be used to predict the mean transit time values for the stomach, the small intestine, and the colon, a study was conducted in 16 healthy volunteers....... After ingestion of a meal containing 111indium-labelled water and 99mtechnetium-labelled omelette, imaging was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small...... intestinal and colonic mean transit times were calculated for both markers and compared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Highly significant correlations were found between gastric mean transit time...

  4. Lifetime measurements in transitional nuclei by fast electronic scintillation timing

    Science.gov (United States)

    Caprio, M. A.; Zamfir, N. V.; Casten, R. F.; Amro, H.; Barton, C. J.; Beausang, C. W.; Cooper, J. R.; Gürdal, G.; Hecht, A. A.; Hutter, C.; Krücken, R.; McCutchan, E. A.; Meyer, D. A.; Novak, J. R.; Pietralla, N.; Ressler, J. J.; Berant, Z.; Brenner, D. S.; Gill, R. L.; Regan, P. H.

    2002-10-01

    A new generation of experiments studying nuclei in spherical-deformed transition regions has been motivated by the introduction of innovative theoretical approaches to the treatment of these nuclei. The important structural signatures in the transition regions, beyond the basic yrast level properties, involve γ-ray transitions between low-spin, non-yrast levels, and so information on γ-ray branching ratios and absolute matrix elements (or level lifetimes) for these transitions is crucial. A fast electronic scintillation timing (FEST) system [H. Mach, R. L. Gill, and M. Moszyński, Nucl. Instrum. Methods A 280, 49 (1989)], making use of BaF2 and plastic scintillation detectors, has been implemented at the Yale Moving Tape Collector for the measurement of lifetimes of states populated in β^ decay. Experiments in the A100 (Pd, Ru) and A150 (Dy, Yb) regions have been carried out, and a few examples will be presented. Supported by the US DOE under grants and contracts DE-FG02-91ER-40609, DE-FG02-88ER-40417, and DE-AC02-98CH10886 and by the German DFG under grant Pi 393/1.

  5. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VIII. CATALOG OF TRANSIT TIMING MEASUREMENTS OF THE FIRST TWELVE QUARTERS

    Energy Technology Data Exchange (ETDEWEB)

    Mazeh, Tsevi; Nachmani, Gil; Holczer, Tomer; Sokol, Gil [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 Ellis Ave., Chicago, IL 60637 (United States); Ford, Eric B.; Ragozzine, Darin [Astronomy Department, University of Florida, Gainesville, FL 32111 (United States); Sanchis-Ojeda, Roberto [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Zucker, Shay [Department of Geophysical, Atmospheric and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University, 69978 Tel Aviv (Israel); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Quintana, Elisa V. [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, CA 94043 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Welsh, William [Astronomy Department, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States)

    2013-10-01

    Following the works of Ford et al. and Steffen et al. we derived the transit timing of 1960 Kepler objects of interest (KOIs) using the pre-search data conditioning light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough signal-to-noise ratios, we obtained also the duration and depth of each transit. The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations. Including systems found by previous works, we have found 130 KOIs that showed highly significant times of transit variations (TTVs) and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV—the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

  6. Simplified scintigraphic methods for measuring gastrointestinal transit times

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2000-01-01

    . After ingestion of a meal containing 111indium-labelled water and 99mtechnetium-labelled omelette, imaging was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small...... intestinal and colonic mean transit times were calculated for both markers and compared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Highly significant correlations were found between gastric mean transit time...... and fractional gastric emptying at 2 h (111In: r=0.95, P

  7. Pharyngeal transit time measured by scintigraphic and biomagnetic method

    International Nuclear Information System (INIS)

    Miquelin, C.A.; Braga, F.J.H.N.; Baffa, O.

    1996-01-01

    A comparative evaluation between scintigraphic and biomagnetic method to measure the pharyngeal transit is presented. Three volunteers have been studied. The aliment (yogurt) was labeled with 9 9 m Technetium for the scintigraphic test and with ferrite for the biomagnetic one. The preliminary results indicate a difference between the values obtained, probably due to the biomagnetic detector resolution

  8. Stopped-flow technique for transit time measurement in a gas jet

    International Nuclear Information System (INIS)

    Rengan, K.; Lin, J.; Lim, T.; Meyer, R.A.; Harrell, J.

    1985-01-01

    A 'stopped-flow' technique for the measurement of transit time of reaction products in a gas jet is described. The method involved establishing the gas flow through the jet system when the reactor is operating steadily and allowing the pressure to reach equilibrium values. The gas flow is stopped by means of electrically operated valves. The transit-time measurement is achieved by opening the valves and initiating the multiscanning of total activity simultaneously. The value obtained agrees well with the transit time measured by pulsing the reactor. The 'stopped-flow' technique allows on-line measurement of transit time in any gas jet system where the physical transportation time is the major component of the transit time. This technique is especially useful for systems installed in reactors which do not have pulsing capability. (orig.)

  9. Measurement and evaluation of transit travel time reliability

    Science.gov (United States)

    2011-01-01

    Transportation system customers need consistency in their daily travel times to enable them to plan their daily : activities, whether that is a commuter on their way to work, a company setting up delivery schedules for justintime : manufacturin...

  10. Proof of Concept: Design and Initial Evaluation of a Device to Measure Gastrointestinal Transit Time.

    Science.gov (United States)

    Wagner, Robert H; Savir-Baruch, Bital; Halama, James R; Venu, Mukund; Gabriel, Medhat S; Bova, Davide

    2017-09-01

    Chronic constipation and gastrointestinal motility disorders constitute a large part of a gastroenterology practice and have a significant impact on a patient's quality of life and lifestyle. In most cases, medications are prescribed to alleviate symptoms without there being an objective measurement of response. Commonly used investigations of gastrointestinal transit times are currently limited to radiopaque markers or electronic capsules. Repeated use of these techniques is limited because of the radiation exposure and the significant cost of the devices. We present the proof of concept for a new device to measure gastrointestinal transit time using commonly available and inexpensive materials with only a small amount of radiotracer. Methods: We assembled gelatin capsules containing a 67 Ga-citrate-radiolabeled grain of rice embedded in paraffin for use as a point-source transit device. It was tested for stability in vitro and subsequently was given orally to 4 healthy volunteers and 10 patients with constipation or diarrhea. Imaging was performed at regular intervals until the device was excreted. Results: The device remained intact and visible as a point source in all subjects until excretion. When used along with a diary of bowel movement times and dates, the device could determine the total transit time. The device could be visualized either alone or in combination with a barium small-bowel follow-through study or a gastric emptying study. Conclusion: The use of a point-source transit device for the determination of gastrointestinal transit time is a feasible alternative to other methods. The device is inexpensive and easy to assemble, requires only a small amount of radiotracer, and remains inert throughout the gastrointestinal tract, allowing for accurate determination of gastrointestinal transit time. Further investigation of the device is required to establish optimum imaging parameters and reference values. Measurements of gastrointestinal transit time

  11. Flow-rate measurement using radioactive tracers and transit time method

    International Nuclear Information System (INIS)

    Turtiainen, Heikki

    1986-08-01

    The transit time method is a flow measurement method based on tracer techniques. Measurement is done by injecting to the flow a pulse of tracer and measuring its transit time between two detection positions. From the transit time the mean flow velosity and - using the pipe cross section area - the volume flow rate can be calculated. When a radioisotope tracer is used the measurement can be done from outside the pipe and without disturbing the process (excluding the tracer injection). The use of the transit time method has been limited because of difficulties associated with handling and availability of radioactive tracers and lack of equipment suitable for routine use in industrial environments. The purpose of this study was to find out if these difficulties may be overcome by using a portable isotope generator as a tracer source and automating the measurement. In the study a test rig and measuring equipment based on the use of a ''1''3''7Cs/''1''3''7''''mBa isotope generator were constructed. They were used to study the accuracy and error sources of the method and to compare different algorithms to calculate the transit time. The usability of the method and the equipment in industrial environments were studied by carrying out over 20 flow measurements in paper and pulp mills. On the basis of the results of the study, a project for constructing a compact radiatracer flowmeter for industrial use has been started. The application range of this kind of meter is very large. The most obvious applications are in situ calibration of flowmeters, material and energy balance studies, process equipment analyses (e.g. pump efficiency analyses). At the moment tracer techniques are the only methods applicable to these measurements on-line and with sufficient accuracy

  12. The Measurement of Time: Children's Construction of Transitivity, Unit Iteration, and Conservation of Speed.

    Science.gov (United States)

    Long, Kathy; Kamii, Constance

    2001-01-01

    Interviews 120 children in kindergarten and grades 2, 4, and 6 with five Piagetian tasks to determine the grade level at which most have constructed transitive reasoning, unit iteration, and conservation of speed. Indicates that construction of the logic necessary to make sense of the measurement of time is generally not complete before sixth…

  13. Measuring the diameter of rising gas bubbles by means of the ultrasound transit time technique

    Energy Technology Data Exchange (ETDEWEB)

    Richter, T., E-mail: Thomas.Richter6@tu-dresden.de; Eckert, K., E-mail: Kerstin.Eckert@tu-dresden.de; Yang, X.; Odenbach, S.

    2015-09-15

    Highlights: • Ultrasound transit time technique (UTTT) is applied to the zig-zag raise of gas bubble. • Comparison of bubble diameter and tilt, measured by UTTT, with high-speed imaging. • Uncertainty in the determination of the bubble diameter by UTTT is less than 7%. • UTTT is able to measure dynamic changes in bubble size in opaque liquids and vessels. • UTTT can be applied to liquid metal loops. - Abstract: This study presents ultrasound transit time technique (UTTT) measurements of the diameter variations of single argon bubbles rising in a zig-zag trajectory in water. Simultaneous size measurements with a high-speed camera show that UTTT resolves both the apparent diameter and the tilt of the bubble axis with an accuracy of better than 7%. This qualifies UTTT for the measurement of bubble sizes in opaque liquids, such as liquid metals, or vessels.

  14. Assessment of Tandem Measurements of pH and Total Gut Transit Time in Healthy Volunteers

    OpenAIRE

    Mikolajczyk, Adam E; Watson, Sydeaka; Surma, Bonnie L; Rubin, David T

    2015-01-01

    Objectives: The variation of luminal pH and transit time in an individual is unknown, yet is necessary to interpret single measurements. This study aimed to assess the intrasubject variability of gut pH and transit time in healthy volunteers using SmartPill devices (Covidien, Minneapolis, MN). Methods: Each subject (n=10) ingested two SmartPill devices separated by 24?h. Mean pH values were calculated for 30?min after gastric emptying (AGE), before the ileocecal (BIC) valve, after the ileocec...

  15. [Evaluation and Optimization of Microvascular Arterial Anastomoses by Transit Time Flow Measurement].

    Science.gov (United States)

    Herberhold, S; Röttker, J; Bartmann, D; Solbach, A; Keiner, S; Welz, A; Bootz, F; Laffers, W

    2016-03-01

    INDRODUCTION: The regular application of transit time flow measurement in microvascular anastomoses during heart surgery has lead to improvements of the outcome of coronary artery bypass grafts. Our study was meant to discover whether this measurement method was also applicable for evaluation and optimization of microvascular arterial anastomoses of radial forearm flaps. In this prospective examination a combining ultrasound imaging and transit time flow measurement device (VeriQ, MediStim) was used during surgery to assess anastomotic quality of 15 radial forearm flaps. Pulsatility index (PI) and mean blood flow were measured immediately after opening the arterial anastomosis as well as 15 min afterwards. Furthermore, application time and description of handling were recorded seperately for every assessment. Mean blood flow immediately after opening the anastomosis and 15 min later were 3.9 and 3.4 ml/min resepectively showing no statistically significant difference (p=0.96). There was no significance in the increase of pulsatility index from 22.1 to 27.2 (p=0.09) during the same time range, either. Due to measurement results showing atypical pulse curves in 2 cases decision for surgical revision of the anastomoses was made. All forearm flaps showed good vascularisation during follow-up. Time for device set up, probe placement and measurements was about 20 min. Handling was described to be uncomplicated without exception. There were no noteworthy problems. Transit time flow measurement contributes to the improvement of anastomotic quality and therefore to the overall outcome of radial forearm flaps. The examined measurement method provides objective results and is useful for documentation purposes. © Georg Thieme Verlag KG Stuttgart · New York.

  16. A transit-time flow meter for measuring milliliter per minute liquid flow

    DEFF Research Database (Denmark)

    Yang, Canqian; Kymmel, Mogens; Søeberg, Henrik

    1988-01-01

    A transit-time flow meter, using periodic temperature fluctuations as tracers, has been developed for measuring liquid flow as small as 0.1 ml/min in microchannels. By injecting square waves of heat into the liquid flow upstream with a tiny resistance wire heater, periodic temperature fluctuation....... This flow meter will be used to measure and control the small liquid flow in microchannels in flow injection analysis. Review of Scientific Instruments is copyrighted by The American Institute of Physics....... are generated downstream. The fundamental frequency phase shift of the temperature signal with respect to the square wave is found to be a linear function of the reciprocal mean velocity of the fluid. The transit-time principle enables the flow meter to have high accuracy, better than 0.2%, and good linearity...

  17. Time dependency of local cerebral blood flow measurements caused by regional variations in tissue transit time

    International Nuclear Information System (INIS)

    Lear, J.L.; Kasliwal, R.; Feyerabend, A.

    1990-01-01

    Calculated values of local cerebral blood flow (LCBF) using the diffusible tracer model are assumed to be independent of time as long as experiments are brief enough to prevent tissue saturation. This paper investigates the effects of CTT variation on LCBF measurements. Using double-label quantitative digital autoradiography, we compared iodoantipyrine (IAP)-based LCBF measurements obtained with tracer infusions of different lengths of time. Lightly anesthetized rats were given simultaneous ramp infusions of C-14 IAP (45 seconds) and I-123 IAP (15 seconds) and immediately sacrificed. Two autoradiograms of each brain section, one representing I-123 and the other representing C-14, were produced, digitized, and converted into images of LCBF based on the 15- and 45-second infusion periods. The LCBF image pairs were compared on a pixel-by-pixel basis

  18. Smartphone-based Continuous Blood Pressure Measurement Using Pulse Transit Time.

    Science.gov (United States)

    Gholamhosseini, Hamid; Meintjes, Andries; Baig, Mirza; Linden, Maria

    2016-01-01

    The increasing availability of low cost and easy to use personalized medical monitoring devices has opened the door for new and innovative methods of health monitoring to emerge. Cuff-less and continuous methods of measuring blood pressure are particularly attractive as blood pressure is one of the most important measurements of long term cardiovascular health. Current methods of noninvasive blood pressure measurement are based on inflation and deflation of a cuff with some effects on arteries where blood pressure is being measured. This inflation can also cause patient discomfort and alter the measurement results. In this work, a mobile application was developed to collate the PhotoPlethysmoGramm (PPG) waveform provided by a pulse oximeter and the electrocardiogram (ECG) for calculating the pulse transit time. This information is then indirectly related to the user's systolic blood pressure. The developed application successfully connects to the PPG and ECG monitoring devices using Bluetooth wireless connection and stores the data onto an online server. The pulse transit time is estimated in real time and the user's systolic blood pressure can be estimated after the system has been calibrated. The synchronization between the two devices was found to pose a challenge to this method of continuous blood pressure monitoring. However, the implemented continuous blood pressure monitoring system effectively serves as a proof of concept. This combined with the massive benefits that an accurate and robust continuous blood pressure monitoring system would provide indicates that it is certainly worthwhile to further develop this system.

  19. Measurement of small bowel transit time by 99Tcm-SC imaging: preliminary clinical study

    International Nuclear Information System (INIS)

    Zhang Shaohua; Xu Jingying; Bei Lian; Zhu Chaohui; Ba Jiantao

    1999-01-01

    Objective: To develop a method of measuring small bowel transit time (SBTT) by 99 Tc m -sulfur collide (SC) imaging and to compare with the method of added lactose in the test meal. Methods: 20 healthy volunteers and 26 patients with gastrointestinal disorders were studied. In fasting state, the subjects were asked to ingest the 99 Tc m -SC labelled solid meal within 5 minutes, then the image acquisition was immediately started with SPECT. The images were acquired every 15 min during the first hour, at 30 min intervals during 2∼4 hours and hourly thereafter until 80% radioactivity had entered the colon. One week later, the same procedure of imaging with 15 g lactulose added in the test meal was performed. The regions of interest (ROIs) were taken at stomach and colon, and the SBTT was calculated by deconvolution or by subtraction of the 50% time of gastric emptying from the 50% time of colon filling. Results: 1) The mean SBTT of 20 healthy volunteers was (4.2 +- 0.5) h, oral-caecum transit time (OCTT) was (4.3 +- 0.6) h; lactulose shortened the SBTT by (1.8 +- 0.6) h; 2) 26 patients showed different results of SBTT due to their different gastrointestinal disorders bases. Conclusions: 99 Tc m -SC imaging was a noninvasive and useful method to measure SBTT. The added lactulose can shorten the examination time and help to identify the time of food to the ileocecal region

  20. An Investigation of Pulse Transit Time as a Non-Invasive Blood Pressure Measurement Method

    International Nuclear Information System (INIS)

    McCarthy, B M; O'Flynn, B; Mathewson, A

    2011-01-01

    The objective of this paper is to examine the Pulse Transit Method (PTT) as a non-invasive means to track Blood Pressure over a short period of time. PTT was measured as the time it takes for an ECG R-wave to propagate to the finger, where it is detected by a photoplethysmograph sensor. The PTT method is ideal for continuous 24-hour Blood Pressure Measurement (BPM) since it is both cuff-less and non-invasive and therefore comfortable and unobtrusive for the patient. Other techniques, such as the oscillometric method, have shown to be accurate and reliable but require a cuff for operation, making them unsuitable for long term monitoring. Although a relatively new technique, the PTT method has shown to be able to accurately track blood pressure changes over short periods of time, after which re-calibration is necessary. The purpose of this study is to determine the accuracy of the method.

  1. Noninvasive measurement of cerebrospinal fluid flow using an ultrasonic transit time flow sensor: a preliminary study.

    Science.gov (United States)

    Pennell, Thomas; Yi, Juneyoung L; Kaufman, Bruce A; Krishnamurthy, Satish

    2016-03-01

    OBJECT Mechanical failure-which is the primary cause of CSF shunt malfunction-is not readily diagnosed, and the specific reasons for mechanical failure are not easily discerned. Prior attempts to measure CSF flow noninvasively have lacked the ability to either quantitatively or qualitatively obtain data. To address these needs, this preliminary study evaluates an ultrasonic transit time flow sensor in pediatric and adult patients with external ventricular drains (EVDs). One goal was to confirm the stated accuracy of the sensor in a clinical setting. A second goal was to observe the sensor's capability to record real-time continuous CSF flow. The final goal was to observe recordings during instances of flow blockage or lack of flow in order to determine the sensor's ability to identify these changes. METHODS A total of 5 pediatric and 11 adult patients who had received EVDs for the treatment of hydrocephalus were studied in a hospital setting. The primary EVD was connected to a secondary study EVD that contained a fluid-filled pressure transducer and an in-line transit time flow sensor. Comparisons were made between the weight of the drainage bag and the flow measured via the sensor in order to confirm its accuracy. Data from the pressure transducer and the flow sensor were recorded continuously at 100 Hz for a period of 24 hours by a data acquisition system, while the hourly CSF flow into the drip chamber was recorded manually. Changes in the patient's neurological status and their time points were noted. RESULTS The flow sensor demonstrated a proven accuracy of ± 15% or ± 2 ml/hr. The flow sensor allowed real-time continuous flow waveform data recordings. Dynamic analysis of CSF flow waveforms allowed the calculation of the pressure-volume index. Lastly, the sensor was able to diagnose a blocked catheter and distinguish between the blockage and lack of flow. CONCLUSIONS The Transonic flow sensor accurately measures CSF output within ± 15% or ± 2 ml

  2. Measurement of oro-caecal transit time by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Savarino, Edoardo; De Cassan, Chiara [Division of Gastroenterology, Department of Surgical, Oncological and Gastroenterological Sciences, Padua (Italy); Savarino, Vincenzo; Furnari, Manuele; Marabotto, Elisa; Gemignani, Lorenzo; Bruzzone, Luca; Moscatelli, Alessandro [University of Genoa, Division of Gastroenterology, Department of Internal Medicine, Genoa (Italy); Fox, Mark [Queen' s Medical Center, NIHR Biomedical Research Unit, Nottingham Digestive Diseases Centre, Nottingham (United Kingdom); Di Leo, Giovanni [IRCCS Policlinico San Donato, Servizio di Radiologia, San Donato Milanese (Italy); Sardanelli, Francesco; Sconfienza, Luca Maria [IRCCS Policlinico San Donato, Servizio di Radiologia, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese, Milano (Italy)

    2015-06-01

    To assess prospectively the agreement of orocaecal transit time (OCTT) measurements by lactulose hydrogen breath test (LHBT) and magnetic resonance imaging (MRI) in healthy subjects. Volunteers underwent abdominal 1.5-T MRI using axial and coronal single-shot fast-spin-echo T2-weighted sequences, having fasted and after lactulose ingestion (10 g/125 mL). Imaging and H{sub 2} excretion gas-chromatography were performed concurrently every 15 min up to 180 min. MR images were analyzed using semiautomatic segmentation to calculate small bowel gas volume (SBGV) and visually to detect bolus arrival in the caecum. Agreement between MRI- and LHBT-OCTT was assessed. Twenty-eight subjects (17 men/11 women; mean age ± standard deviation 30 ± 8 years) were evaluated. Two H{sub 2} non-producers on LHBT were excluded. OCTT measured by MRI and LHBT was concordant in 18/26 (69 %) subjects (excellent agreement, k = 0.924). Median SBGV was 49.0 mL (interquartile interval 44.1 - 51.6 mL). In 8/26 (31 %) subjects, MRI showed that the lactulose bolus was in the terminal ileum and not the caecum when H{sub 2}E increased on LHBT. Median OCTT measured by MRI was significantly longer than OCTT measured by LHBT [135 min (120 - 150 min) vs. 127.5 min (105 - 150 min); p = 0.008]. Above baseline levels, correlation between [H{sub 2}] and SBGV was significant (r = 0.964; p < 0.001). MRI provides valid measurements of OCTT and gas production in the small bowel. (orig.)

  3. Increasing accuracy of pulse transit time measurements by automated elimination of distorted photoplethysmography waves

    NARCIS (Netherlands)

    M.H.N. van Velzen (M. H N); A.J. Loeve (Arjo J.); S.P. Niehof (Sjoerd); E.G. Mik (Egbert)

    2017-01-01

    textabstractPhotoplethysmography (PPG) is a widely available non-invasive optical technique to visualize pressure pulse waves (PWs). Pulse transit time (PTT) is a physiological parameter that is often derived from calculations on ECG and PPG signals and is based on tightly defined characteristics of

  4. Increasing accuracy of pulse transit time measurements by automated elimination of distorted photoplethysmography waves

    NARCIS (Netherlands)

    van Velzen, M.H.N.; Loeve, A.J.; Niehof, S.P.; Mik, E.G.

    2017-01-01

    Photoplethysmography (PPG) is a widely available non-invasive optical technique to visualize pressure pulse waves (PWs). Pulse transit time (PTT) is a physiological parameter that is often derived from calculations on ECG and PPG signals and is based on tightly defined characteristics of the PW

  5. Increasing accuracy of pulse transit time measurements by automated elimination of distorted photoplethysmography waves.

    Science.gov (United States)

    van Velzen, Marit H N; Loeve, Arjo J; Niehof, Sjoerd P; Mik, Egbert G

    2017-11-01

    Photoplethysmography (PPG) is a widely available non-invasive optical technique to visualize pressure pulse waves (PWs). Pulse transit time (PTT) is a physiological parameter that is often derived from calculations on ECG and PPG signals and is based on tightly defined characteristics of the PW shape. PPG signals are sensitive to artefacts. Coughing or movement of the subject can affect PW shapes that much that the PWs become unsuitable for further analysis. The aim of this study was to develop an algorithm that automatically and objectively eliminates unsuitable PWs. In order to develop a proper algorithm for eliminating unsuitable PWs, a literature study was conducted. Next, a '7Step PW-Filter' algorithm was developed that applies seven criteria to determine whether a PW matches the characteristics required to allow PTT calculation. To validate whether the '7Step PW-Filter' eliminates only and all unsuitable PWs, its elimination results were compared to the outcome of manual elimination of unsuitable PWs. The '7Step PW-Filter' had a sensitivity of 96.3% and a specificity of 99.3%. The overall accuracy of the '7Step PW-Filter' for detection of unsuitable PWs was 99.3%. Compared to manual elimination, using the '7Step PW-Filter' reduces PW elimination times from hours to minutes and helps to increase the validity, reliability and reproducibility of PTT data.

  6. Assessment of the Variation Associated with Repeated Measurement of Gastrointestinal Transit Times and Assessment of the Effect of Oral Ranitidine on Gastrointestinal Transit Times Using a Wireless Motility Capsule System in Dogs

    Directory of Open Access Journals (Sweden)

    Jonathan A. Lidbury

    2012-01-01

    Full Text Available This study aimed to evaluate the variation associated with repeated measurement of gastrointestinal (GI transit times and the effect of oral ranitidine on GI transit times in healthy dogs using a wireless motility capsule (WMC system. Eight privately owned healthy adult dogs were enrolled, and one developed diarrhea and was removed from the study. For the first 3 repetitions, each dog was fed a standard meal followed by oral administration of a WMC. For the 4th repetition, each dog was given ranitidine hydrochloride (75 mg PO every 12 hours prior to and during assessment of GI transit times. Mean between-subject coefficients of variation for gastric emptying time (GET, small and large bowel transit time (SLBTT, and total transit time (TTT were 26.9%, 32.3%, and 19.6%, respectively. Mean within-subject coefficients of variation for GET, SLBTT, and TTT were 9.3%, 19.6%, and 15.9%, respectively. Median GET, SLBTT, and TTT without ranitidine were 719, 1,636, and 2,735 minutes, respectively. Median GET, SLBTT, and TTT with ranitidine were 757, 1,227, and 2,083 minutes, respectively. No significant differences in GI transit times were found between any of the 4 repetitions. Under these experimental conditions, no significant effects of oral ranitidine on GI transit times were observed.

  7. Positron life time and annihilation Doppler broadening measurements on transition metal complexes

    International Nuclear Information System (INIS)

    Levay, B.; Burger, K.

    1982-01-01

    Positron life time and annihilation Doppler broadening measurements have been carried out on 44 solid coordination compounds. Several correlations have been found between the annihilation life time (tau 1 ) and line shape parameters (L) and the chemical structure of the compounds. Halide ligands were the most active towards positrons. This fact supports the assumption on the possible formation of [e + X - ] positron-halide bound state. The life time was decreasing and the annihilation energy spectra were broadening with the increasing negative character of the halides. The aromatic base ligands affected the positron-halide interaction according to their basicity and space requirement and thus they indirectly affected the annihilation parameters, too. In the planar and tetrahedral complexes the electron density on the central met--al ion affected directly the annihilation parameters, while in the octahedral mixed complexes it had only an ind--irect effect through the polarization of the halide ligands. (author)

  8. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, E F; Strandberg, C; Bendtsen, F

    1999-01-01

    with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...... echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  9. Tc-99m-Human Serum Albumin Transit Time as a Measure of Arm Breast Cancer-Related Lymphedema

    DEFF Research Database (Denmark)

    Toyserkani, Navid M; Hvidsten, Svend; Tabatabaeifar, Siavosh

    2017-01-01

    34-68 years, with unilateral arm lymphedema following breast cancer treatment underwent bilateral lymphoscintigraphy using intradermal injection in both hands of technetium-99m-labeled human serum albumin and sequential 5 min imaging for 5 hours. The mean transit time (MTT) in the arms was calculated...... based on time activity curves generated from injection site and arm regions. Visual lymphedema scoring was performed based on dermal backflow and lymph node presence. Excess arm volume was calculated from circumference measurements. RESULTS: The MTT (mean ± SD) was significantly longer in the lymphedema...

  10. Validation of transit-time flowmetry for chronic measurements of regional blood flow in resting and exercising rats

    Directory of Open Access Journals (Sweden)

    S.L. Amaral

    1997-07-01

    Full Text Available The objective of the present study was to validate the transit-time technique for long-term measurements of iliac and renal blood flow in rats. Flow measured with ultrasonic probes was confirmed ex vivo using excised arteries perfused at varying flow rates. An implanted 1-mm probe reproduced with accuracy different patterns of flow relative to pressure in freely moving rats and accurately quantitated the resting iliac flow value (on average 10.43 ± 0.99 ml/min or 2.78 ± 0.3 ml min-1 100 g body weight-1. The measurements were stable over an experimental period of one week but were affected by probe size (resting flows were underestimated by 57% with a 2-mm probe when compared with a 1-mm probe and by anesthesia (in the same rats, iliac flow was reduced by 50-60% when compared to the conscious state. Instantaneous changes of iliac and renal flow during exercise and recovery were accurately measured by the transit-time technique. Iliac flow increased instantaneously at the beginning of mild exercise (from 12.03 ± 1.06 to 25.55 ± 3.89 ml/min at 15 s and showed a smaller increase when exercise intensity increased further, reaching a plateau of 38.43 ± 1.92 ml/min at the 4th min of moderate exercise intensity. In contrast, exercise-induced reduction of renal flow was smaller and slower, with 18% and 25% decreases at mild and moderate exercise intensities. Our data indicate that transit-time flowmetry is a reliable method for long-term and continuous measurements of regional blood flow at rest and can be used to quantitate the dynamic flow changes that characterize exercise and recovery

  11. Identifiability analysis of rotational diffusion tensor and electronic transition moments measured in time-resolved fluorescence depolarization experiment

    International Nuclear Information System (INIS)

    Szubiakowski, Jacek P.

    2014-01-01

    The subject of this paper is studies of the deterministic identifiability of molecular parameters, such as rotational diffusion tensor components and orientation of electronic transition moments, resulting from the time-resolved fluorescence anisotropy experiment. In the most general case considered, a pair of perpendicularly polarized emissions enables the unique determination of all the rotational diffusion tensor's principal components. The influence of the tensor's symmetry and the associated degeneration of its eigenvalues on the identifiability of the electronic transitions moments is systematically investigated. The analysis reveals that independently of the rotational diffusion tensor's symmetry, the transition moments involved in photoselection and emission processes cannot be uniquely identified without a priori information about their mutual orientation or their orientation with respect to the principal axes of the tensor. Moreover, it is shown that increasing the symmetry of the rotational diffusion tensor deteriorates the degree of the transition moments identifiability. To obtain these results analytically, a novel approach to solve bilinear system of equations for Markov parameters is applied. The effect of the additional information, obtained from fluorescence measurements for different molecular mobilities, to improve the identifiability at various levels of analysis is shown. The effectiveness and reliability of the target analysis method for experimental determination of the molecular parameters is also discussed

  12. Dynamic measurements of reflux for quantifying gastroesophageal reflux in patients with prolonged esophageal transit time

    International Nuclear Information System (INIS)

    Gratz, K.F.; Creutzig, H.; Schmiedt, W.; Oelert, H.; Hundeshagen, H.; Medizinische Hochschule Hannover

    1985-01-01

    A combination of a radionuclide transit test and a dynamic gastroesophageal scan was evaluated in normal volunteers, in patients with achalasia treated by pneumatic dilatation (n=34) or Heller myotomy (n=21). Interpretation of 31 of 57 examinations done with usual scintiscan was not possible because of too high esophageal tracer retention. Only one case could not be interpreted with the modified technique. Gastroesophageal reflux was detected and quantified in this manner in 8 patients, 6 more than with the usual scintiscan. 7 of these 8 patients have had Heller procedure, 1 patient even combined with fundoplasty. (orig.) [de

  13. Dynamic measurements of reflux for quantifying gastroesophageal reflux in patients with prolonged esophageal transit time

    Energy Technology Data Exchange (ETDEWEB)

    Gratz, K.F.; Creutzig, H.; Schmiedt, W.; Oelert, H.; Hundeshagen, H.

    1985-05-01

    A combination of a radionuclide transit test and a dynamic gastroesophageal scan was evaluated in normal volunteers, in patients with achalasia treated by pneumatic dilatation (n=34) or Heller myotomy (n=21). Interpretation of 31 of 57 examinations done with usual scintiscan was not possible because of too high esophageal tracer retention. Only one case could not be interpreted with the modified technique. Gastroesophageal reflux was detected and quantified in this manner in 8 patients, 6 more than with the usual scintiscan. 7 of these 8 patients have had Heller procedure, 1 patient even combined with fundoplasty.

  14. Intraoperative transit-time flow measurement is not altered in venous bypass grafts covered by the eSVS mesh.

    Science.gov (United States)

    Emery, Robert W; Solien, Eric

    2013-01-01

    The aim of this study was to determine whether the eSVS Mesh interferes with transit-time flow measurement (TTFM) assessing intraoperative coronary vein graft patency. In four swine undergoing off-pump bypass grafting to the anterior descending coronary artery, five TTFMs were sequentially obtained on meshed and bare grafts at baseline and under Dobutamine stress at five separate locations on the graft in each animal. The Medistim VeriQ was used for TTFM. The grafts were examined for patency after the swine were killed. There was no difference in hemodynamics or TTFM either at baseline or under Dobutamine stress between the eSVS Mesh covered and uncovered grafts. Dobutamine, however, significantly increased hemodynamics and graft flow parameters measured from baseline. The eSVS Mesh does not interfere with Doppler flow measurement in covered coronary vein grafts.

  15. Time-resolved and volumetric PIV measurements of a transitional separation bubble on an SD7003 airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Burgmann, S.; Dannemann, J.; Schroeder, W. [RWTH Aachen University, Department of Mechanical Engineering, Institute of Aerodynamics, Aachen (Germany)

    2008-04-15

    To comprehensively understand the effects of Kelvin-Helmholtz instabilities on a transitional separation bubble on the suction side of an airfoil regarding as to flapping of the bubble and its impact on the airfoil performance, the temporal and spatial structure of the vortices occurring at the downstream end of the separation bubble is investigated. Since the bubble variation leads to a change of the pressure distribution, the investigation of the instantaneous velocity field is essential to understand the details of the overall airfoil performance. This vortex formation in the reattachment region on the upper surface of an SD7003 airfoil is analyzed in detail at different angles of attack. At a Reynolds number Re{sub c} < 100,000 the laminar boundary layer separates at angles of attack >4 . Due to transition processes, turbulent reattachment of the separated shear layer occurs enclosing a locally confined recirculation region. To identify the location of the separation bubble and to describe the dynamics of the reattachment, a time-resolved PIV measurement in a single light-sheet is performed. To elucidate the spatial structure of the flow patterns in the reattachment region in time and space, a stereo scanning PIV set-up is applied. The flow field is recorded in at least ten successive light-sheet planes with two high-speed cameras enclosing a viewing angle of 65 to detect all three velocity components within a light-sheet leading to a time-resolved volumetric measurement due to a high scanning speed. The measurements evidence the development of quasi-periodic vortex structures. The temporal dynamics of the vortex roll-up, initialized by the Kelvin-Helmholtz (KH) instability, is shown as well as the spatial development of the vortex roll-up process. Based on these measurements a model for the evolving vortex structure consisting of the formation of c-shape vortices and their transformation into screwdriver vortices is introduced. (orig.)

  16. Transit-time flow measurement as a predictor of coronary bypass graft failure at one year angiographic follow-up

    DEFF Research Database (Denmark)

    Lehnert, Per; Møller, Christian H; Damgaard, Sune

    2015-01-01

    on graft vessel type, anastomatic configuration, and coronary artery size. RESULTS: Nine hundred eighty-two coronary anastomoses were performed of which 12% had signs of graft failure at one year angiographic follow-up. In internal mammary arteries (IMAs), analysis showed a 4% decrease in graft failure......BACKGROUND: Transit-time flow measurement (TTFM) is a commonly used intraoperative method for evaluation of coronary artery bypass graft (CABG) anastomoses. This study was undertaken to determine whether TTFM can also be used to predict graft patency at one year postsurgery. METHODS: Three hundred...... forty-five CABG patients with intraoperative graft flow measurements and one year angiographic follow-up were analyzed. Graft failure was defined as more than 50% stenosis including the "string sign." Logistic regression analysis was used to analyze the risk of graft failure after one year based...

  17. Progress in the development of the DTMROC time measurement chip for the ATLAS transition radiation tracker (TRT)

    CERN Document Server

    Alexander, C; Dressnandt, N; Ekenberg, T; Farthouat, Philippe; Keener, P T; Lam, N; La Marra, D; Mann, J; Newcomer, F M; Ryzhov, V; Söderberg, M; Szczygiel, R; Van Berg, R; Williams, H H

    2001-01-01

    A 16-channel digital time-measurement readout chip (DTMROC) has been fabricated in the TEMIC/DM1LL left bracket 1 right bracket BI- CMOS radiation-hard process for the Large Hadron Collider's (LHC) Transition Radiation Tracker (ATLAS/TRT) at CERN left bracket 2 right bracket . The chip receives discriminated straw-drift-tube signals from bipolar amplifier-shaper-discriminator chips (ASDBLR). measures the arrival time in 3.125 ns increments ( plus or minus 1 ns), and stores the data in a pipeline for 3.3mus. A trigger signal (L1A) causes the data to be tagged with a time stamp and stored for readout- Up to 13 events may be stored in an on-chip buffer while data is being clocked out in a 40 MHz serial stream. The chip has been designed to function after exposure to 1x10**1**4 protons/cm**2 and 1 Mrad total dose. System beam-tests have demonstrated measurement of track positions with a resolution of 165mum and 85% efficiency at rates up to 18MHz. 6 Refs.

  18. Effects of cuff inflation and deflation on pulse transit time measured from ECG and multi-wavelength PPG.

    Science.gov (United States)

    Liu, Jing; Li, Yao; Ding, Xiao-Rong; Dai, Wen-Xuan; Zhang, Yuan-Ting

    2015-01-01

    Pulse transit time (PTT), which refers to the time it takes a pulse wave to travel between two arterial sites is a promising index for cuff-less blood pressure (BP) estimation, as well as non-invasive assessment of arterial functions. However, it has not been investigated whether PTTs measured from ECG and different wavelength PPG are equally affected by the arterial status. Furthermore, comparison between the changes of different PTTs can provide enlightenment on the hardware implementation of the PTT-based BP estimation method. This work mainly studied the changes of PTTs calculated from electrocardiogram (ECG) and multi-wavelength photoplethysmogram (PPG) after exerting cuff pressure on the upper arm. A four-channel PPG acquisition system was developed to collect the multi-wavelength PPG signals of red, yellow, green and blue light at the fingertip simultaneously. Ten subjects participated in the experiment and their PTTs measured from different PPG and ECG signals before and after exerting cuff pressure were compared. This study found that within one minute after the four-minute cuff inflation and deflation process, the PTT measured from ECG and yellow PPG experienced a significant increase (p0.9) compared with that before exerting cuff pressure. This indicates that PTTs calculated from different wavelength PPG have different recoverability from smooth muscle relaxation. Another interesting finding is that the PTT calculated from ECG and yellow PPG had a strong correlation (|r|>0.7) with the time difference between yellow PPG and other PPG signals, which implies the potential of the time difference between yellow PPG and other PPGs as a complementary to PTT-based model for blood pressure estimation.

  19. TRANSIT TIMING VARIATION MEASUREMENTS OF WASP-12b AND QATAR-1b: NO EVIDENCE OF ADDITIONAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Karen A.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Kielkopf, John F. [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States)

    2017-02-01

    WASP-12b and Qatar-1b are transiting hot Jupiters for which previous works have suggested the presence of transit timing variations (TTVs) indicative of additional bodies in these systems—an Earth-mass planet in WASP-12 and a brown-dwarf mass object in Qatar-1. Here, we present 23 new WASP-12b and 18 new Qatar-1b complete (or nearly complete) transit observations. We perform global system fits to all of our light curves for each system, as well as RV and stellar spectroscopic parameters from the literature. The global fits provide refined system parameters and uncertainties for each system, including precise transit center times for each transit. The transit model residuals of the combined and five minute binned light curves have an rms of 183 and 255 parts per million (ppm) for WASP-12b and Qatar-1b, respectively. Most of the WASP-12b system parameter values from this work are consistent with values from previous studies, but have ∼40%–50% smaller uncertainties. Most of the Qatar-1b system parameter values and uncertainties from this work are consistent with values recently reported in the literature. We find no convincing evidence for sinusoidal TTVs with a semi-amplitude of more than ∼35 and ∼25 s in the WASP-12b and Qatar-1b systems, respectively.

  20. The study of transit time measurement for flow through the central and southern canals of MADA using I-131 radioisotope technique

    International Nuclear Information System (INIS)

    Roslan Mohd Ali; Md Shahid Ayub; Zainuddin Othman; Juhari Yusof; Mohd Asri Ramli; Eow Boon Tiak

    1996-01-01

    The measurement of breakthrough and transit time through the central and southern canals of Lembaga Kemajuan Pertanian Muda (MADA) by using radiotracer technique is discussed An estimated of 1700 cusec water was released from Pelubang regulator through central canal. The water is then distributed through several regulators down stream and finally ended through the SCD1 and SCD1a secondary canals. Radiotracer 1-131 with the activity of 250 mCi and 500 mCi were injected at several identified injection points by using glass breaker technique. The measurement of breakthrough and transit time were observed respectively at several measurement station. Results of the study indicated that the time travel from Pelubang regulator to SCD1a secondary canal would take about 3 days during normal operation. Detail of breakthrough and transit time at every regulators and other measurement stations were also presented

  1. Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.

    Science.gov (United States)

    Shimizu, Kazuhiro; Kosaka, Nobuyuki; Fujiwara, Yasuhiro; Matsuda, Tsuyoshi; Yamamoto, Tatsuya; Tsuchida, Tatsuro; Tsuchiyama, Katsuki; Oyama, Nobuyuki; Kimura, Hirohiko

    2017-01-10

    The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF). A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by 99m Tc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF. The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P renal ASL-MRI as debated in brain imaging.

  2. Pharyngeal transit time measured by scintigraphic and biomagnetic method; Tempo de transito faringeano medido atraves dos metodos cintilografico e biomagnetico

    Energy Technology Data Exchange (ETDEWEB)

    Miquelin, C.A.; Braga, F.J.H.N.; Baffa, O. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica; Dantas, R.O.; Oliveira, R.B. [Faculdade de Medicina de Ribeirao Preto, SP (Brazil)

    1996-12-31

    A comparative evaluation between scintigraphic and biomagnetic method to measure the pharyngeal transit is presented. Three volunteers have been studied. The aliment (yogurt) was labeled with {sup 9}9{sup m} Technetium for the scintigraphic test and with ferrite for the biomagnetic one. The preliminary results indicate a difference between the values obtained, probably due to the biomagnetic detector resolution 3 refs., 2 figs., 1 tab.

  3. Transit time for resonant tunneling

    International Nuclear Information System (INIS)

    Garcia Calderon, G.; Rubio, A.

    1990-09-01

    This work considers properties of the partial widths in one dimensional elastic resonant tunneling in order to propose a transit-time τ tr = (h/2π)/Γ n T res ) where Γ n is the elastic width and T res the transmission coefficient at resonance energy. This time is interpreted as an average over the resonance energy width. It is shown that the tunneling current density integrated across a sharp resonance is inversely proportional to τ tr . This transit time may be much larger than the values predicted by other definitions. (author). 20 refs

  4. Transit performance measures in California.

    Science.gov (United States)

    2016-04-01

    This research is the result of a California Department of Transportation (Caltrans) request to assess the most commonly : available transit performance measures in California. Caltrans wanted to understand performance measures and data used by : Metr...

  5. Time resolved reflectivity measurements of the amorphous-to-gamma and gamma-to-alpha phase transitions in ion-implanted Al2O3

    International Nuclear Information System (INIS)

    McCallum, J.C.; Simpson, T.W.; Mitchell, I.V.

    1994-01-01

    Time resolved optical reflectivity (TRR) has been used to measure the growth kinetics associated with the amorphous-to-gamma and gamma-to-alpha phase transitions in ion-beam amorphised c-axis oriented α-Al 2 O 3 . The optical reflectivity technique allows the recrystallisation behaviour to be monitored dynamically during regrowth so that the growth kinetics associated with the two phase transitions can be measured simply and accurately from a relatively small number of samples. The amorphous-to-gamma and gamma-to-alpha phase transitions were studied over the temperature ranges of 670-770 C and 900-1070 C, respectively. The growth kinetics obtained for the two transitions are compared to previous work. ((orig.))

  6. Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast-enhanced T1-weighted perfusion MRI

    DEFF Research Database (Denmark)

    Larsson, Henrik B.W.; Vestergaard, Mark B.; Lindberg, Ulrich

    2017-01-01

    Purpose: Capillary transit time heterogeneity, measured as CTH, may set the upper limit for extraction of substances in brain tissue, e.g., oxygen. The purpose of this study was to investigate the feasibility of dynamic contrast-enhanced T1 weighted MRI (DCE-MRI) at 3 Tesla (T), in estimating CTH...

  7. Coordinating Transit Transfers in Real Time

    Science.gov (United States)

    2016-05-06

    Transfers are a major source of travel time variability for transit passengers. Coordinating transfers between transit routes in real time can reduce passenger waiting times and travel time variability, but these benefits need to be contrasted with t...

  8. Orocaecal transit time in Duchenne muscular dystrophy.

    OpenAIRE

    Korman, S H; Bar-Oz, B; Granot, E; Meyer, S

    1991-01-01

    Smooth muscle degeneration may occur in Duchenne muscular dystrophy. We measured fasting orocaecal transit time in patients with advanced Duchenne muscular dystrophy and other muscular dystrophies and in healthy controls. No significant differences were found. In contrast to reports of gastric hypomotility in Duchenne muscular dystrophy, we found no evidence of impaired small intestinal motility.

  9. Phase transition phenomenon: A compound measure analysis

    Science.gov (United States)

    Kang, Bo Soo; Park, Chanhi; Ryu, Doojin; Song, Wonho

    2015-06-01

    This study investigates the well-documented phenomenon of phase transition in financial markets using combined information from both return and volume changes within short time intervals. We suggest a new measure for the phase transition behaviour of markets, calculated as a return distribution conditional on local variance in volume imbalance, and show that this measure successfully captures phase transition behaviour under various conditions. We analyse the intraday trade and quote dataset from the KOSPI 200 index futures, which includes detailed information on the original order size and the type of each initiating investor. We find that among these two competing factors, the submitted order size yields more explanatory power on the phenomenon of market phase transition than the investor type.

  10. Measurement of extracellular volume and transit time heterogeneity using contrast-enhanced myocardial perfusion MRI in patients after acute myocardial infarction.

    Science.gov (United States)

    Kunze, Karl P; Rischpler, Christoph; Hayes, Carmel; Ibrahim, Tareq; Laugwitz, Karl-Ludwig; Haase, Axel; Schwaiger, Markus; Nekolla, Stephan G

    2017-06-01

    To assess the ability of dynamic contrast-enhanced myocardial perfusion MRI to measure extracellular volume (ECV) and to investigate the possibility of estimating capillary transit time heterogeneity (CTH) in patients after myocardial infarction and successful revascularization. Twenty-four perfusion data sets were acquired on a 3 Tesla positron emission tomography (PET)/MRI scanner. Three perfusion models of different complexity were implemented in a hierarchical fashion with an Akaike information criterion being used to determine the number of fit parameters supported by the data. Results were compared sector-wise to ECV from an equilibrium T 1 mapping method (modified look-locker inversion recovery (MOLLI)). ECV derived from the perfusion analysis correlated well with equilibrium measurements (R² = 0.76). Estimation of CTH was supported in 16% of sectors (mostly remote). Inclusion of a nonzero CTH parameter usually led to lower estimates of first-pass extraction and slightly higher estimates of blood volume and flow. Estimation of the capillary permeability-surface area product was feasible in 81% of sectors. Transit time heterogeneity has a measurable effect on the kinetic analysis of myocardial perfusion MRI data, and Gd-DTPA extravasation in the myocardium is usually not flow-limited in infarct-related pathology. Measurement of myocardial ECV using perfusion imaging could provide a scan-time efficient alternative to methods based on T 1 mapping. Magn Reson Med 77:2320-2330, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  11. Characterization of dynamics in complex lyophilized formulations: I. Comparison of relaxation times measured by isothermal calorimetry with data estimated from the width of the glass transition temperature region.

    Science.gov (United States)

    Chieng, Norman; Mizuno, Masayasu; Pikal, Michael

    2013-10-01

    The purposes of this study are to characterize the relaxation dynamics in complex freeze dried formulations and to investigate the quantitative relationship between the structural relaxation time as measured by thermal activity monitor (TAM) and that estimated from the width of the glass transition temperature (ΔT(g)). The latter method has advantages over TAM because it is simple and quick. As part of this objective, we evaluate the accuracy in estimating relaxation time data at higher temperatures (50 °C and 60 °C) from TAM data at lower temperature (40 °C) and glass transition region width (ΔT(g)) data obtained by differential scanning calorimetry. Formulations studied here were hydroxyethyl starch (HES)-disaccharide, HES-polyol, and HES-disaccharide-polyol at various ratios. We also re-examine, using TAM derived relaxation times, the correlation between protein stability (human growth hormone, hGH) and relaxation times explored in a previous report, which employed relaxation time data obtained from ΔT(g). Results show that most of the freeze dried formulations exist in single amorphous phase, and structural relaxation times were successfully measured for these systems. We find a reasonably good correlation between TAM measured relaxation times and corresponding data obtained from estimates based on ΔT(g), but the agreement is only qualitative. The comparison plot showed that TAM data are directly proportional to the 1/3 power of ΔT(g) data, after correcting for an offset. Nevertheless, the correlation between hGH stability and relaxation time remained qualitatively the same as found with using ΔT(g) derived relaxation data, and it was found that the modest extrapolation of TAM data to higher temperatures using ΔT(g) method and TAM data at 40 °C resulted in quantitative agreement with TAM measurements made at 50 °C and 60 °C, provided the TAM experiment temperature, is well below the Tg of the sample. Copyright © 2013 Elsevier B.V. All rights

  12. Transit timing observations from Kepler. V. Transit timing variation candidates in the first sixteen months from polynomial models

    DEFF Research Database (Denmark)

    Ford, E.B.; Ragozzine, D.; Holman, M.J.

    2012-01-01

    Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during...... that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We...

  13. An interface between the nuclear physics and the atomic physics; how to measure nuclear times observing atomic transitions

    International Nuclear Information System (INIS)

    Pinho, A.G. de

    1985-01-01

    Recent observations are related in which processes resulting from the ionization in ion-atom collisions are observed in coincidence with nuclear processes (where the incidence ion nucleus hits the target atom nucleus). The delay introduced by the nuclear reaction contaminates the results of the atomic collision and manifest itself either in the X rays (positrons) emitted in the joined atom system or in the X rays (Auger electrons) emitted by separeted atoms, after the collision. Both effects serve to obtain information on the reaction times (in general much less then 10 -16 sec). Following this line, other experimental possibilities are discussed. (L.C.) [pt

  14. Constructing ordinal partition transition networks from multivariate time series.

    Science.gov (United States)

    Zhang, Jiayang; Zhou, Jie; Tang, Ming; Guo, Heng; Small, Michael; Zou, Yong

    2017-08-10

    A growing number of algorithms have been proposed to map a scalar time series into ordinal partition transition networks. However, most observable phenomena in the empirical sciences are of a multivariate nature. We construct ordinal partition transition networks for multivariate time series. This approach yields weighted directed networks representing the pattern transition properties of time series in velocity space, which hence provides dynamic insights of the underling system. Furthermore, we propose a measure of entropy to characterize ordinal partition transition dynamics, which is sensitive to capturing the possible local geometric changes of phase space trajectories. We demonstrate the applicability of pattern transition networks to capture phase coherence to non-coherence transitions, and to characterize paths to phase synchronizations. Therefore, we conclude that the ordinal partition transition network approach provides complementary insight to the traditional symbolic analysis of nonlinear multivariate time series.

  15. Radiocardiography of minimal transit times: a useful diagnostic procedure

    International Nuclear Information System (INIS)

    Schicha, H.; Vyska, K.; Becker, V.; Feinendegen, L.E.; Duesseldorf Univ., F.R. Germany)

    1975-01-01

    Contrary to mean transit times, minimal transit times are the differences between arrival times of an indicator. Arrival times in various cardiac compartments can be easily measured with radioisotopes and fast gamma cameras permitting data processing. This paper summarizes data selected from more than 1500 measurements made so far on normal individuals and patients with valvular heart disease, myocardial insufficiency, digitalis effect, atrial fibrillation, hypothyroidism, hyperthyroidism, effort-syndrome and coronary artery disease. (author)

  16. Improvements in Low-cost Ultrasonic Measurements of Blood Flow in "by-passes" Using Narrow & Broad Band Transit-time Procedures

    Science.gov (United States)

    Ramos, A.; Calas, H.; Diez, L.; Moreno, E.; Prohías, J.; Villar, A.; Carrillo, E.; Jiménez, A.; Pereira, W. C. A.; Von Krüger, M. A.

    The cardio-pathology by ischemia is an important cause of death, but the re-vascularization of coronary arteries (by-pass operation) is an useful solution to reduce associated morbidity improving quality of life in patients. During these surgeries, the flow in coronary vessels must be measured, using non-invasive ultrasonic methods, known as transit time flow measurements (TTFM), which are the most accurate option nowadays. TTFM is a common intra-operative tool, in conjunction with classic Doppler velocimetry, to check the quality of these surgery processes for implanting grafts in parallel with the coronary arteries. This work shows important improvements achieved in flow-metering, obtained in our research laboratories (CSIC, ICIMAF, COPPE) and tested under real surgical conditions in Cardiocentro-HHA, for both narrowband NB and broadband BB regimes, by applying results of a CYTED multinational project (Ultrasonic & computational systems for cardiovascular diagnostics). mathematical models and phantoms were created to evaluate accurately flow measurements, in laboratory conditions, before our new electronic designs and low-cost implementations, improving previous ttfm systems, which include analogic detection, acquisition & post-processing, and a portable PC. Both regimes (NB and BB), with complementary performances for different conditions, were considered. Finally, specific software was developed to offer facilities to surgeons in their interventions.

  17. Late time phase transition as dark energy

    Indian Academy of Sciences (India)

    Abstract. We show that the dark energy field can naturally be described by the scalar condensates of a non-abelian gauge group. This gauge group is unified with the standard model gauge groups and it has a late time phase transition. The small phase transition explains why the positive acceleration of the universe is ...

  18. Chalk Catchment Transit Time: Unresolved Issues

    Energy Technology Data Exchange (ETDEWEB)

    Darling, W. G.; Gooddy, D. C. [British Geological Survey, Crowmarsh Gifford, Wallingford, Oxfordshire (United Kingdom); Barker, J. A. [School of Civil Engineering and the Environment, University of Southampton, Southampton (United Kingdom); Robinson, M. [Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire (United Kingdom)

    2013-07-15

    The mean transit time (MTT) of a catchment is the average residence time of water from rainfall to river outflow at the foot of the catchment. As such, MTT has important water quality as well as resource implications. Many catchments worldwide have been measured for MTT using environmental isotopes, yet the Chalk, an important aquifer in NW Europe, has received little attention in this regard. The catchment of the River Lambourn in southern England has been intermittently studied since the 1960s using isotopic methods. A tritium peak measured in the river during the 1970s indicates an apparent MTT of {approx}15 years, but the thick unsaturated zone (average {approx}50 m) of the catchment suggests that the MTT should be much greater because of the average downward movement through the Chalk of {approx}1 m/a consistently indicated by tritium and other tracers. Recent work in the catchment using SF{sub 6} as a residence time indicator has given groundwater ages in the narrow range 11-18 yrs, apparently supporting the river tritium data but in conflict with the unsaturated zone data even allowing for a moderate proportion of rapid bypass flow. The MTT of the catchment remains unresolved for the time being. (author)

  19. A search for transit timing variation

    Directory of Open Access Journals (Sweden)

    Kramm U.

    2011-02-01

    Full Text Available Photometric follow-ups of transiting exoplanets (TEPs may lead to discoveries of additional, less massive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. In 2009 we launched an international observing campaign, the aim of which is to detect and characterise signals of transit timing variation (TTV in selected TEPs. The programme is realised by collecting data from 0.6-2.2-m telescopes spread worldwide at different longitudes. We present our observing strategy and summarise first results for WASP-3b with evidence for a 15 Earth-mass perturber in an outer 2:1 orbital resonance.

  20. Hemodynamic evaluation before and after the STA-MCA anastomosis; With special reference to measurement of regional transit time with intra-arterial digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Touho, Hajime; Karasawa, Jun; Shishido, Hisashi; Yamada, Keisuke; Shibamoto, Keiji [Osaka Neurological Inst. Toyonaka (Japan)

    1990-09-01

    Twenty-seven patients with minor completed and major stroke in the chronic stage underwent superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. The regional cerebral blood flow (rCBF), using inhalation of stable xenon and computed tomographic scanning (Xe{sup s} CT-CBF study), and the mode of transit time (MTT) in the MCA territory using intra-arterial digital aortography were measured. Activated rCBF and MTT was measured 20 minutes after the administration of acetazolamide (10 mg/kg) in 14 patients. Nineteen of the 23 patients with minor stroke (Group 1) showed immediate improvement in their neurological state within a few days of the operation, while four patients with minor stroke (Group 2) and four patients with major stroke (Group 3) showed no improvement. Based on the rCBF obtained with the Xe{sup s} CT-CBF study, affected side rCBF/unaffected side rCBF and %f ((peak DSA number/affected side MTT)/(peak DSA number/unaffected side MTT)) were compared. There was a significant positive correlation. Affected side MTT in Group 1 was 6.41{plus minus}1.16 sec, preoperatively, and significantly decreased to 5.13{plus minus}0.91 sec after the operation. On the other hand, preoperative MTT in Group 2 was 4.40{plus minus}0.81 sec and 4.76{plus minus}0.89 sec, postoperatively. Preoperative %f in Group 1 was 0.514{plus minus}0.143 and significantly increased to 0.739{plus minus}0.154, postoperatively. Group 2 showed no change. Vasodilatory capacity with acetazolamide showed a marked improvement in Group 1, postoperativery. Our study indicated that if MTT is moderately lengthened, %f is moderately decreased, and vasodilatory capacity is impaired, in patients with minor ischemic stroke will benefit from STA-MCA anastomosis. (author).

  1. Late-time cosmological phase transitions

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1990-11-01

    It is shown that the potential galaxy formation and large-scale structure problems of objects existing at high redshifts (Z approx-gt 5), structures existing on scales of 100M pc as well as velocity flows on such scales, and minimal microwave anisotropies (ΔT/T) approx-lt 10 -5 can be solved if the seeds needed to generate structure form in a vacuum phase transition after decoupling. It is argued that the basic physics of such a phase transition is no more exotic than that utilized in the more traditional GUT scale phase transitions, and that, just as in the GUT case, significant random gaussian fluctuations and/or topological defects can form. Scale lengths of ∼100M pc for large-scale structure as well as ∼1 M pc for galaxy formation occur naturally. Possible support for new physics that might be associated with such a late-time transition comes from the preliminary results of the SAGE solar neutrino experiment, implying neutrino flavor mixing with values similar to those required for a late-time transition. It is also noted that a see-saw model for the neutrino masses might also imply a tau neutrino mass that is an ideal hot dark matter candidate. However, in general either hot or cold dark matter can be consistent with a late-time transition. 47 refs., 2 figs

  2. TRANSIT TIMING OBSERVATIONS FROM KEPLER. V. TRANSIT TIMING VARIATION CANDIDATES IN THE FIRST SIXTEEN MONTHS FROM POLYNOMIAL MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Ragozzine, Darin; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rowe, Jason F.; Barclay, Thomas; Borucki, William J.; Bryson, Stephen T.; Caldwell, Douglas A.; Kinemuchi, Karen; Koch, David G.; Lissauer, Jack J.; Still, Martin; Tenenbaum, Peter [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Gautier, Thomas N. [Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109 (United States); Ibrahim, Khadeejah A.; Uddin, Kamal [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Kjeldsen, Hans, E-mail: eford@astro.ufl.edu [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); and others

    2012-09-10

    Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during the first sixteen months of Kepler observations. We present 39 strong TTV candidates based on long-term trends (2.8% of suitable data sets). We present another 136 weaker TTV candidates (9.8% of suitable data sets) based on the excess scatter of TTV measurements about a linear ephemeris. We anticipate that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We find that the occurrence rate of planet candidates that show TTVs is significantly increased ({approx}68%) for planet candidates transiting stars with multiple transiting planet candidates when compared to planet candidates transiting stars with a single transiting planet candidate.

  3. Verifying duration properties of timed transition systems

    DEFF Research Database (Denmark)

    Liu, Zhiming; Ravn, Anders P.; Li, Xiaoshan

    1998-01-01

    This paper proposes a method for formal real-time systems development:Requirements and high level design decisions are time interval properties and are therefore specified in the Duration Calculus (DC), while implementations are described bytimed transition systems (TTS). A link from implementati...

  4. Transition Icons for Time-Series Visualization and Exploratory Analysis.

    Science.gov (United States)

    Nickerson, Paul V; Baharloo, Raheleh; Wanigatunga, Amal A; Manini, Todd M; Tighe, Patrick J; Rashidi, Parisa

    2018-03-01

    The modern healthcare landscape has seen the rapid emergence of techniques and devices that temporally monitor and record physiological signals. The prevalence of time-series data within the healthcare field necessitates the development of methods that can analyze the data in order to draw meaningful conclusions. Time-series behavior is notoriously difficult to intuitively understand due to its intrinsic high-dimensionality, which is compounded in the case of analyzing groups of time series collected from different patients. Our framework, which we call transition icons, renders common patterns in a visual format useful for understanding the shared behavior within groups of time series. Transition icons are adept at detecting and displaying subtle differences and similarities, e.g., between measurements taken from patients receiving different treatment strategies or stratified by demographics. We introduce various methods that collectively allow for exploratory analysis of groups of time series, while being free of distribution assumptions and including simple heuristics for parameter determination. Our technique extracts discrete transition patterns from symbolic aggregate approXimation representations, and compiles transition frequencies into a bag of patterns constructed for each group. These transition frequencies are normalized and aligned in icon form to intuitively display the underlying patterns. We demonstrate the transition icon technique for two time-series datasets-postoperative pain scores, and hip-worn accelerometer activity counts. We believe transition icons can be an important tool for researchers approaching time-series data, as they give rich and intuitive information about collective time-series behaviors.

  5. Gibbs measures and phase transitions

    CERN Document Server

    Georgii, Hans-Otto

    2011-01-01

    From a review of the first edition: ""This book […] covers in depth a broad range of topics in the mathematical theory of phase transition in statistical mechanics. […] It is in fact one of the author's stated aims that this comprehensive monograph should serve both as an introductory text and as a reference for the expert."" (F. Papangelou, Zentralblatt MATH) The second edition has been extended by a new section on large deviations and some comments on the more recent developments in the area.

  6. First measurements of electron-beam transit times and micropulse elongation in a photoelectric injector at the High-Brightness Accelerator FEL (HIBAF)

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.; Carlsten, B.E.; Feldman, R.B.

    1990-01-01

    Key aspects of the dynamics of a photoelectric injector (PEI) on the Los Alamos High-Brightness Accelerator FEL (HIBAF) facility have been investigated using a synchroscan streak camera. By phase-locking the streak camera sweep to the reference 108.3 MHz rf signal, the variations of micropulse temporal elongations (30 to 80% over the drive-laser pulse length) and of transit times (25 ps for a 16{degree}-phase change) were observed for the first time. These results were in good agreement with PARMELA simulations. 2 refs., 8 figs.

  7. Clinical value of radionuclide small intestine transit time measurement combined with lactulose hydrogen breath test for the diagnosis of bacterial overgrowth in irritable bowel syndrome.

    Science.gov (United States)

    Ning, Yanli; Lou, Cen; Huang, Zhongke; Chen, Dongfang; Huang, Huacheng; Chen, Liang; Zhang, Bucheng; Dai, Ning; Zhao, Jianmin; Zhen, Xia

    2016-01-01

    Small intestine bacterial overgrowth (SIBO) may be a pathogenetic factor for irritable bowel syndrome (IBS). This syndrome cannot be explained by structural abnormalities and has no specific diagnostic laboratory tests or biomarkers. We studied quantitatively and semi-quantitatively, using lactulose hydrogen breath test (LHBT), small intestinal transit time (SITT) (99m)technetium-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in order to examine the mobility of small intestine as an indication of bacterial overgrowth in patients. Eighty nine consecutive patients who met Rome criteria for IBS were retrospectively studied. According to the diagnostic criteria, all patients were divided into two groups: the SIBO group and the non-SIBO group. The tracer was a mixture of 10g lactulose, 37MBq (99m)Tc-DTPA and 100mL water. The patient drank the whole mixture during 1min and the SITT study started immediately. The SITT and the LHBT followed every 15min for up to 3h after emptying the urine bladder. Spearman's rank correlation was applied to assess the correlation of oro-cecum transit time (OCTT) between imaging and LHBT. The semi-quantitative index between the SIBO group and the non-SIBO group was analyzed with Wilcoxon's rank sum test. If there was significant group difference, the receiver operating characteristic (ROC) curve was used. Pintestinal transit time study using a lactose hydrogen breath test and (99m)Tc-DTPA is a real-time test for small intestine bacteria overgrowth in IBS patients and can be used as an indicator of the disease.

  8. Measurement of arterial transit time and renal blood flow using pseudocontinuous ASL MRI with multiple post-labeling delays: Feasibility, reproducibility, and variation.

    Science.gov (United States)

    Kim, Dong Won; Shim, Woo Hyun; Yoon, Seong Kuk; Oh, Jong Yeong; Kim, Jeong Kon; Jung, Hoesu; Matsuda, Tsuyoshi; Kim, Dongeun

    2017-09-01

    To evaluate the feasibility, reproducibility, and variation of renal perfusion and arterial transit time (ATT) using pseudocontinuous arterial spin labeling magnetic resonance imaging (PCASL MRI) in healthy volunteers. PCASL MRI at 3T was performed in 25 healthy volunteers on two different occasions. The ATT and ATT-corrected renal blood flow (ATT-cRBF) were calculated at four different post-labeling delay points (0.5, 1.0, 1.5, and 2.0 s) and evaluated for each kidney and subject. The intraclass correlation (ICC) and Bland-Altman plot were used to assess the reproducibility of the PCASL MRI technique. The within-subject coefficient of variance was determined. Results were obtained for 46 kidneys of 23 subjects with a mean age of 38.6 ± 9.8 years and estimated glomerular filtration rate (eGFR) of 89.1 ± 21.2 ml/min/1.73 m 2 . Two subjects failed in the ASL MRI examination. The mean cortical and medullary ATT-cRBF for the subjects were 215 ± 65 and 81 ± 21 ml/min/100 g, respectively, and the mean cortical and medullary ATT were 1141 ± 262 and 1123 ± 245 msec, correspondingly. The ICC for the cortical ATT-cRBF was 0.927 and the within-subject coefficient of variance was 14.4%. The ICCs for the medullary ATT-cRBF and the cortical and medullary ATT were poor. The Bland-Altman plot for cortical RBF showed good agreement between the two measurements. PCASL MRI is a feasible and reproducible method for measuring renal cortical perfusion. In contrast, ATT for the renal cortex and medulla has poor reproducibility and high variation. 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:813-819. © 2017 International Society for Magnetic Resonance in Medicine.

  9. Beam induced transit time signals at SPEAR

    International Nuclear Information System (INIS)

    McConnell, R.A.

    1975-01-01

    Beam induced signals at frequencies related to inter-cavity transit times have been detected at SPEAR. Whether this effect enters significantly into beam instabilities has not yet been determined. Preliminary experiments suggest that under certain conditions at low energy (1.5 GeV) , when μ/sub s/, passes through one of the transit time resonances, some current is lost. Care must be taken, however, not to confuse this effect, if it exists, with synchrobetatron resonances and with an as yet unexplained vertical instability in SPEAR. At high energy (3.7 GeV), no effect has been shown to exist, though detectable signals are present. 2 refs., 2 tabs

  10. Uniqueness in time measurement

    International Nuclear Information System (INIS)

    Lorenzen, P.

    1981-01-01

    According to P. Janich a clock is defined as an apparatus in which a point ( hand ) is moving uniformly on a straight line ( path ). For the definition of uniformly first the scaling (as a constant ratio of velocities) is defined without clocks. Thereafter the uniqueness of the time measurement can be proved using the prove of scaling of all clocks. But the uniqueness can be defined without scaling, as it is pointed out here. (orig.) [de

  11. Real-time measurements of nitrogen oxide emissions from in-use New York City transit buses using a chase vehicle.

    Science.gov (United States)

    Shorter, Joanne H; Herndon, Scott; Zahniser, Mark S; Nelson, David D; Wormhoudt, Joda; Demerjian, Kenneth L; Kolb, Charles E

    2005-10-15

    New diesel engine technologies and alternative fuel engines are being introduced into fleets of mass transit buses to try to meet stricter emission regulations of nitrogen oxides and particulates: Real-time instruments including an Aerodyne Research tunable infrared laser differential absorption spectrometer (TILDAS) were deployed in a mobile laboratory to assess the impact of the implementation of the new technologies on nitrogen oxide emissions in real world driving conditions. Using a "chase" vehicle sampling strategy, the mobile laboratory followed target vehicles, repeatedly sampling their exhaust. Nitrogen oxides from approximately 170 in-use New York City mass transit buses were sampled during the field campaigns. Emissions from conventional diesel buses, diesel buses with continuously regenerating technology (CRT), diesel hybrid electric buses, and compressed natural gas (CNG) buses were compared. The chase vehicle sampling method yields real world emissions that can be included in more realistic emission inventories. The NO, emissions from the diesel and CNG buses were comparable. The hybrid electric buses had approximately one-half the NOx emissions. In CRT diesels, NO2 accounts for about one-third of the NOx emitted in the exhaust, while for non-CRT buses the NO2 fraction is less than 10%.

  12. Linking age, survival, and transit time distributions

    Science.gov (United States)

    Calabrese, Salvatore; Porporato, Amilcare

    2015-10-01

    Although the concepts of age, survival, and transit time have been widely used in many fields, including population dynamics, chemical engineering, and hydrology, a comprehensive mathematical framework is still missing. Here we discuss several relationships among these quantities by starting from the evolution equation for the joint distribution of age and survival, from which the equations for age and survival time readily follow. It also becomes apparent how the statistical dependence between age and survival is directly related to either the age dependence of the loss function or the survival-time dependence of the input function. The solution of the joint distribution equation also allows us to obtain the relationships between the age at exit (or death) and the survival time at input (or birth), as well as to stress the symmetries of the various distributions under time reversal. The transit time is then obtained as a sum of the age and survival time, and its properties are discussed along with the general relationships between their mean values. The special case of steady state case is analyzed in detail. Some examples, inspired by hydrologic applications, are presented to illustrate the theory with the specific results. This article was corrected on 11 Nov 2015. See the end of the full text for details.

  13. Computerprogram for the determination of minimal cardiac transit times

    International Nuclear Information System (INIS)

    Bosiljanoff, P.; Herzog, H.; Schmid, A.; Sommer, D.; Vyska, K.; Feinendegen, L.E.

    1982-10-01

    An Anger-Type gamma-camera is used to register the first pass of a radioactive tracer of blood flow through the heart. The acquired data are processed by a suitable computer program yielding time-activity curves for sequential heart segments, which are selected by the region of interest technique. The program prints the minimal cardiac transit times, in terms of total transit times, as well as segmental transit times for the right atrium, right ventricle, lung, left atrium and left ventricle. The measured values are normalized to a rate of 80/min and are compared to normal mean values. The deviation from the normal mean values is characterized by a coefficient F. Moreover, these findings are qualitatively rated. (orig./MG)

  14. Constipation and Colonic Transit Times in Children With Morbid Obesity

    NARCIS (Netherlands)

    van der Baan-Slootweg, Olga H.; Liem, Olivia; Bekkali, Noor; van Aalderen, Wim M. C.; Rijcken, Tammo H. Pels; Di Lorenzo, Carlo; Benninga, Marc A.

    2011-01-01

    Objectives: The aim of the study was to determine the frequency of functional constipation according to the Rome III criteria in children with morbid obesity and to evaluate by measuring colonic transit times (CTTs) whether decreased colonic motility is present in these children. Patients and

  15. Transit-time instability in Hall thrusters

    International Nuclear Information System (INIS)

    Barral, Serge; Makowski, Karol; Peradzynski, Zbigniew; Dudeck, Michel

    2005-01-01

    Longitudinal waves characterized by a phase velocity of the order of the velocity of ions have been recurrently observed in Hall thruster experiments and simulations. The origin of this so-called ion transit-time instability is investigated with a simple one-dimensional fluid model of a Hall thruster discharge in which cold ions are accelerated between two electrodes within a quasineutral plasma. A short-wave asymptotics applied to linearized equations shows that plasma perturbations in such a device consist of quasineutral ion acoustic waves superimposed on a background standing wave generated by discharge current oscillations. Under adequate circumstances and, in particular, at high ionization levels, acoustic waves are amplified as they propagate, inducing strong perturbation of the ion density and velocity. Responding to the subsequent perturbation of the column resistivity, the discharge current generates a standing wave, the reflection of which sustains the generation of acoustic waves at the inlet boundary. A calculation of the frequency and growth rate of this resonance mechanism for a supersonic ion flow is proposed, which illustrates the influence of the ionization degree on their onset and the approximate scaling of the frequency with the ion transit time. Consistent with experimental reports, the traveling wave can be observed on plasma density and velocity perturbations, while the plasma potential ostensibly oscillates in phase along the discharge

  16. Using connectivity for measuring equity in transit provision

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Popoks, Dmitrijs; Prato, Carlo Giacomo

    2014-01-01

    . In addition, transit connectivity weighs the impedance components according to their relative importance to travelers. The assessment of equity was performed for the multi-modal transit system in the Greater Copenhagen Area, renowned for its transit-oriented finger-plan. The assessment method used a GIS...... representation of the network (i.e., service lines, timetables, metro stations, train stations, and bus stops), and transit assignment results (i.e., level-of-service times, passenger flows). The assessment method proved effective in calculating location-based and potential-accessibility measures and Gini...... coefficients of inequality in the Greater Copenhagen Area. Results show that the transit-oriented development contributes to spatial equity with high connectivity in densely populated zones, vertical equity with comparable connectivity in high income and low income zones, inter-generational equity with good...

  17. Real-time subway information for improving transit ridership.

    Science.gov (United States)

    2016-08-01

    In recent years, the standardization of transit schedule information has yielded a dramatic increase in the accessibility of computerized transit schedules and given rise to real-time service schedules. Two such real-time service schedules are the Ge...

  18. Measuring Business Cycle Time.

    OpenAIRE

    Stock, James H

    1987-01-01

    The business cycle analysis of Arthur F. Burns and Wesley C. Mitchell and the National Bureau of Economic Research presumed that aggregate economic variables evolve on a time scale defined by business cycle turning points rather than by months or quarters. Do macroeconomic variables appear to evolve on an economic rather than a calendar time scale? Evidence presented here suggests that they do. However, the estimated economic time scales are only weakly related to business cycle time scales, ...

  19. FTA real-time transit information assessment : white paper on literature review of real-time transit information systems.

    Science.gov (United States)

    Real-time transit information systems are key technology applications within the transit industry designed to provide better customer service by disseminating timely and accurate information. Riders use this information to make various decisions abou...

  20. Pharyngeal Pressure and Timing During Bolus Transit

    Science.gov (United States)

    Walczak, Chelsea C.; Jones, Corinne A.; McCulloch, Timothy M.

    2018-01-01

    Determining intrabolus pressure (IBP) at the upper esophageal sphincter (UES) and in the esophagus has given compelling evidence that IBP can be a predictor for swallowing dysfunction. Studies have looked most superiorly at the low hypopharynx region but there has been no inquiry into what IBP measures throughout the entire pharynx can tell us. We present a study to describe the pressures within and surrounding the moving bolus throughout the pharynx and into the UES. Simultaneous HRM and videofluoroscopy were performed in 10 healthy subjects swallowing ten 10 mL thin-liquid barium boluses. Three events surrounding bolus movement were tracked via videofluoroscopy, two additional events were found using manometric measures. As the bolus passes through the pharynx, low pressure is created at and below the head of the bolus. A modest pressure increase is seen as the bolus passes through the pharynx and finally, high pressure is observed at the bolus tail, followed by an even larger pressure generation of a clearance event. HRM allows for greater resolution in data collection in the pharynx and in this study, aided in identifying semi unique characteristics around the hypopharynx and the UES which are consistent with the complex anatomy of the regions and the transition of the UES from active closure to relaxed opening. In the future, additional studies designed to look at aged and diseased populations may lead to better understanding of disease etiology, and treatment options. PMID:27565155

  1. Signatures of a dissipative phase transition in photon correlation measurements

    Science.gov (United States)

    Fink, Thomas; Schade, Anne; Höfling, Sven; Schneider, Christian; Imamoglu, Ataç

    2018-04-01

    Understanding and characterizing phase transitions in driven-dissipative systems constitutes a new frontier for many-body physics1-8. A generic feature of dissipative phase transitions is a vanishing gap in the Liouvillian spectrum9, which leads to long-lived deviations from the steady state as the system is driven towards the transition. Here, we show that photon correlation measurements can be used to characterize the corresponding critical slowing down of non-equilibrium dynamics. We focus on the extensively studied phenomenon of optical bistability in GaAs cavity polaritons10,11, which can be described as a first-order dissipative phase transition12-14. Increasing the excitation strength towards the bistable range results in an increasing photon-bunching signal along with a decay time that is prolonged by more than nine orders of magnitude as compared with that of single polaritons. In the limit of strong polariton interactions leading to pronounced quantum fluctuations, the mean-field bistability threshold is washed out. Nevertheless, the functional form with which the Liouvillian gap closes as the thermodynamic limit is approached provides a signature of the emerging dissipative phase transition. Our results establish photon correlation measurements as an invaluable tool for studying dynamical properties of dissipative phase transitions without requiring phase-sensitive interferometric measurements.

  2. 'Stutter timing' for charge decay time measurement

    International Nuclear Information System (INIS)

    Chubb, John; Harbour, John; Pavey, Ian

    2011-01-01

    The paper describes the approach of 'stutter timing' that has been developed to improve the accuracy of measuring charge decay times in the presence of noise in compact and portable charge decay test instrumentation. The approach involves starting and stopping the timing clock as the noisy signal rises above and falls below the target threshold voltage level.

  3. Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

    International Nuclear Information System (INIS)

    Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon; Park, Sun-Won; Hwang, Moonjung; Lebel, R.M.

    2018-01-01

    This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

  4. Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Hwang, Moonjung [GE Healthcare Korea, Seoul (Korea, Republic of); Lebel, R.M. [GE Healthcare Canada, Calgary (Canada)

    2018-03-15

    This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

  5. Colonic transit time in patient with slow-transit constipation: Comparison of radiopaque markers and barium suspension method

    Energy Technology Data Exchange (ETDEWEB)

    Xu Huimin [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Department of General Surgery, Weifang People' s Hospital, ShanDong Province 261041 (China); Han Jiagang [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Na Ying [Department of Medical Imaging, Weifang People' s Hospital, ShanDong Province 261041 (China); Zhao Bo; Ma Huachong [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Wang Zhenjun, E-mail: wang3zj@sohu.com [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China)

    2011-08-15

    Background: Colonic transit study provides valuable information before surgical treatment is considered for patient with constipation. The radiopaque markers method is the most common way for evaluating colon transit time. The aim of this study is to compare the barium suspension with the radiopaque makers to assess the colonic mobility in patient with constipation. Methods: Colonic transit time was measured in 11 female patients with slow-transit constipation using both radiopaque markers and barium suspension method. In radiopaque markers method, the patient ingested 20 markers on the first day, and an abdominal radiograph was performed every 24 h until 80% markers were excreted. In barium suspension method, the patient swallowed up to 50 ml of 200% (w/v) barium meal. The abdominal radiographs were taken at the same time point as the former. Results: The total or segmental colonic transit time were obviously prolonged in all patients. Segmental transits time spent in the right colon, left colon and rectosigmoid for radiopaque markers and barium suspension method was, respectively, 30 {+-} 6 h and 34 {+-} 7 h; 38 {+-} 9 h and 32 {+-} 6 h; 40 {+-} 8 h and 38 {+-} 10 h. In the radiopaque markers method, total colonic transit time was 108 {+-} 14 h and it was 103 {+-} 13 h in the barium suspension method (P > 0.05). Conclusion: The barium suspension and radiopaque markers gave the similar results for colonic transit time. The barium suspension was a simple and cheap method for evaluating the colonic mobility.

  6. Colonic transit time in patient with slow-transit constipation: Comparison of radiopaque markers and barium suspension method

    International Nuclear Information System (INIS)

    Xu Huimin; Han Jiagang; Na Ying; Zhao Bo; Ma Huachong; Wang Zhenjun

    2011-01-01

    Background: Colonic transit study provides valuable information before surgical treatment is considered for patient with constipation. The radiopaque markers method is the most common way for evaluating colon transit time. The aim of this study is to compare the barium suspension with the radiopaque makers to assess the colonic mobility in patient with constipation. Methods: Colonic transit time was measured in 11 female patients with slow-transit constipation using both radiopaque markers and barium suspension method. In radiopaque markers method, the patient ingested 20 markers on the first day, and an abdominal radiograph was performed every 24 h until 80% markers were excreted. In barium suspension method, the patient swallowed up to 50 ml of 200% (w/v) barium meal. The abdominal radiographs were taken at the same time point as the former. Results: The total or segmental colonic transit time were obviously prolonged in all patients. Segmental transits time spent in the right colon, left colon and rectosigmoid for radiopaque markers and barium suspension method was, respectively, 30 ± 6 h and 34 ± 7 h; 38 ± 9 h and 32 ± 6 h; 40 ± 8 h and 38 ± 10 h. In the radiopaque markers method, total colonic transit time was 108 ± 14 h and it was 103 ± 13 h in the barium suspension method (P > 0.05). Conclusion: The barium suspension and radiopaque markers gave the similar results for colonic transit time. The barium suspension was a simple and cheap method for evaluating the colonic mobility.

  7. Taste and Temperature in Swallowing Transit Time after Stroke

    Directory of Open Access Journals (Sweden)

    Paula C. Cola

    2012-09-01

    Full Text Available Background: Oropharyngeal dysphagia is common in individuals after stroke. Taste and temperature are used in dysphagia rehabilitation. The influence of stimuli, such as taste and temperature, on swallowing biomechanics has been investigated in both healthy individuals and in individuals with neurological disease. However, some questions still remain unanswered, such as how the sequence of offered stimuli influences the pharyngeal response. The goal of the present study was to determine the influence of the sequence of stimuli, sour taste and cold temperature, on pharyngeal transit time during deglutition in individuals after stroke. Methods: The study included 60 individuals with unilateral ischemic stroke, 29 males and 31 females, aged 41–88 years (mean age: 66.2 years examined 0–50 days after ictus (median: 6 days, with mild to moderate oropharyngeal dysphagia. Exclusion criteria were hemorrhagic stroke patients, patients with decreased level of consciousness, and clinically unstable patients, as confirmed by medical evaluation. The individuals were divided into two groups of 30 individuals each. Group 1 received a nonrandomized sequence of stimuli (i.e. natural, cold, sour, and sour-cold and group 2 received a randomized sequence of stimuli. A videofluoroscopic swallowing study was performed to analyze the pharyngeal transit time. Four different stimuli (natural, cold, sour, and sour-cold were offered. The images were digitalized and specific software was used to measure the pharyngeal transit time. Since the values did not present regular distribution and uniform variances, nonparametric tests were performed. Results: Individuals in group 1 presented a significantly shorter pharyngeal transit time with the sour-cold stimulus than with the other stimuli. Individuals in group 2 did not show a significant difference in pharyngeal transit time between stimuli. Conclusions: The results showed that the sequence of offered stimuli influences

  8. Relationship between functional elongated colonic transit time and constipation

    International Nuclear Information System (INIS)

    Xie Yuchang; Qian Xuequn; Zhang Genfu

    2002-01-01

    Objective: To retrospectively analyze the role of colonic transit test in diagnosis and aetiology of constipation. Methods: 87 cases of constipation diagnosed under Agachan scoring system and having completed transit test at least once were enrolled. All cases were divided into two groups: group A have normal colonic transit time, group B have extended colonic transit time. A comparison of the ratio of rectosigmoid transit by total colon (RRT) between group A and B. Result: 32 cases were enrolled in group A and 55 in group B. Low value of RRT was presented in 10 cases out of 32 in group A (31.3%), while in group B the abnormality was observed in 9 cases out of 55 (16.4%). A statistical difference between the two group was revealed by x 2 test (P < 0.01). Conclusion: Colonic transit test helps the confirming the aetiology of constipation, and the evaluation of rectosigmoid transit function is especially valuable

  9. Thermocouple correlation transit time flowmeter tests at WCL

    International Nuclear Information System (INIS)

    Lassahn, G.D.

    1976-11-01

    Scoping tests indicate the feasibility for using transit time flowmeters with thermocouple sensors in steam-water steady state flow. Conclusive results were not obtained. More conclusive results are expected from tests to be conducted in the semiscale facility with a redesigned transit time thermocouple sensor

  10. Regional gastrointestinal transit times in severe ulcerative colitis.

    Science.gov (United States)

    Haase, A M; Gregersen, T; Christensen, L A; Agnholt, J; Dahlerup, J F; Schlageter, V; Krogh, K

    2016-02-01

    Gastrointestinal (GI) dysmotility may present secondary to inflammatory bowel disease. The main aim of this study was to investigate GI motility in ulcerative colitis (UC) patients during severe disease activity. Twenty patients with severe UC were studied with a novel telemetric capsule system (3D-Transit) designed for minimally invasive, ambulatory assessment of total and regional GI transit times. Ten patients were available for follow-up during remission. Data were compared to those of 20 healthy subjects (HS). Total GI transit time was significantly longer in patients with severe UC (median 44.5 h [range 9.9-102.7 h]) than in HS (median 27.6 h [range 9.6-56.4 h]) (p = 0.032). Additionally, during severe UC, transit time was prolonged through the proximal colon (p = 0.003) and there were strong trends toward longer than normal small intestinal transit time (HS: median 4.9 h [range 3.4-8.3 h] vs severe UC patients: median 5.9 h [range 3.9-11.9 h]; p = 0.053) and colorectal transit times (HS: median 18.2 h [range 1.5-43.7] vs severe UC patients: median 34.9 h [range 0.4-90.9 h]; p = 0.056). Our data further indicate that total GI and colorectal transit times may be prolonged in UC during early remission. Total GI transit times are significantly prolonged during severe UC. © 2016 John Wiley & Sons Ltd.

  11. How many segments are necessary to characterize delayed colonic transit time?

    Science.gov (United States)

    Bouchoucha, Michel; Devroede, Ghislain; Bon, Cyriaque; Raynaud, Jean-Jacques; Bejou, Bakhtiar; Benamouzig, Robert

    2015-10-01

    Measuring colonic transit time with radiopaque markers is simple, inexpensive, and very useful in constipated patients. Yet, the algorithm used to identify colonic segments is subjective, rather than founded on prior experimentation. The aim of the present study is to describe a rational way to determine the colonic partition in the measurement of colonic transit time. Colonic transit time was measured in seven segments: ascending colon, hepatic flexure, right and left transverse colon, splenic flexure, descending colon, and rectosigmoid in 852 patients with functional bowel and anorectal disorders. An unsupervised algorithm for modeling Gaussian mixtures served to estimate the number of subgroups from this oversegmented colonic transit time. After that, we performed a k-means clustering that separated the observations into homogenous groups of patients according to their oversegmented colonic transit time. The Gaussian mixture followed by the k-means clustering defined 4 populations of patients: "normal and fast transit" (n = 548) and three groups of patients with delayed colonic transit time "right delay" (n = 82) in which transit is delayed in the right part of the colon, "left delay" (n = 87) with transit delayed in the left part of colon and "outlet constipation" (n = 135) for patients with transit delayed in the terminal intestine. Only 3.7 % of patients were "erroneously" classified in the 4 groups recognized by clustering. This unsupervised analysis of segmental colonic transit time shows that the classical division of the colon and the rectum into three segments is sufficient to characterize delayed segmental colonic transit time.

  12. Scintigraphic measurement of regional gut transit in idiopathic constipation

    International Nuclear Information System (INIS)

    Stivland, T.; Camilleri, M.; Vassallo, M.; Proano, M.; Rath, D.; Brown, M.; Thomforde, G.; Pemberton, J.; Phillips, S.

    1991-01-01

    In this study, total gut transit and regional colonic transit in patients with idiopathic constipation were measured scintigraphically. Eight patients with severe constipation were studied, none of whom had evidence of abnormal function of the pelvic floor. 99mTc-radiolabeled Amberlite resin particles with a mixed meal were used to assess gastric emptying and small bowel transit; similar particles labeled with 111In were ingested in a coated capsule that dispersed in the ileocecal region. These were used to quantify colonic transit. Five healthy volunteers were also studied. Two patients showed delayed gastric emptying and two had slow small bowel transit. Seven of the eight patients had slow colonic transit. In five, delay affected the whole colon (pancolonic inertia); in two, transit in the ascending and transverse colon was normal, but solids moved through the left colon slowly. Mean colonic transit was also measured using radiopaque markers; this technique identified the patients with slow transit, as shown by measurements of overall colonic transit by simultaneous scintigraphy. However, estimated transit through the ascending and transverse colons was considerably shorter by the radiopaque marker technique. In conclusion, idiopathic constipation is characterized by either exaggerated reservoir functions of the ascending and transverse colons and/or impairment of propulsive function in the descending colon. Particle size may influence the result of regional colonic transit tests. Transit delays in other parts of the gut suggest that, in some patients, the condition may be a more generalized motor dysfunction

  13. Scintigraphic measurement of regional gut transit in idiopathic constipation

    Energy Technology Data Exchange (ETDEWEB)

    Stivland, T.; Camilleri, M.; Vassallo, M.; Proano, M.; Rath, D.; Brown, M.; Thomforde, G.; Pemberton, J.; Phillips, S. (Gastroenterology Research Unit, Mayo Clinic, Rochester, Minnesota (USA))

    1991-07-01

    In this study, total gut transit and regional colonic transit in patients with idiopathic constipation were measured scintigraphically. Eight patients with severe constipation were studied, none of whom had evidence of abnormal function of the pelvic floor. 99mTc-radiolabeled Amberlite resin particles with a mixed meal were used to assess gastric emptying and small bowel transit; similar particles labeled with 111In were ingested in a coated capsule that dispersed in the ileocecal region. These were used to quantify colonic transit. Five healthy volunteers were also studied. Two patients showed delayed gastric emptying and two had slow small bowel transit. Seven of the eight patients had slow colonic transit. In five, delay affected the whole colon (pancolonic inertia); in two, transit in the ascending and transverse colon was normal, but solids moved through the left colon slowly. Mean colonic transit was also measured using radiopaque markers; this technique identified the patients with slow transit, as shown by measurements of overall colonic transit by simultaneous scintigraphy. However, estimated transit through the ascending and transverse colons was considerably shorter by the radiopaque marker technique. In conclusion, idiopathic constipation is characterized by either exaggerated reservoir functions of the ascending and transverse colons and/or impairment of propulsive function in the descending colon. Particle size may influence the result of regional colonic transit tests. Transit delays in other parts of the gut suggest that, in some patients, the condition may be a more generalized motor dysfunction.

  14. Performance measures for public transit mobility management.

    Science.gov (United States)

    2011-12-01

    "Mobility management is an innovative approach for managing and delivering coordinated public : transportation services that embraces the full family of public transit options. At a national level, there are : currently no industry recognized perform...

  15. The meaning of transit times in NDT of reinforced concrete

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2007-10-01

    Transit times of longitudinal pulses that travel near reinforcing steel bars are usually smaller than in plain concrete. Chung first, and then Bungey, demonstrated the importance of including bar diameters in the correction factors when pulses propagating parallel and near to the bars can not be avoided. Besides the influence of geometric dispersion and mode conversion on pulse propagation, there is an effect due to a specific pattern of radial variation of longitudinal wave velocities from the surface of the embedded steel bar. Wall effects produce a region (a sheath) of concrete surrounding the steel bar, with smaller longitudinal pulse velocities in comparison with the velocity farther away from the bar. Then the acoustics energy travels trapped in a kind of composite leaky waveguide with a velocity less than the compression (P) wave velocity in steel and in concrete but greater than the extensional wave velocity in steel. A mathematical model of the propagation of a longitudinal wave-packet is constructed, taking into account both attenuation and dispersion effects. An asymptotic analysis of pulse propagation and the introduction of a threshold of detection in the receiving transducer, allows the derivation of an approximate analytical formula for transit times. Then the meaning of transit times in NDT of concrete is discussed. The above mentioned formula is used to study the effects of the reinforcing bar radius, the propagation parameters in plain concrete and in the sheath surrounding the steel bar, the path length between the transmitting and the receiving transducers, and the energy and the spectral composition of the pulse injected by the emitter in the tested body. Chung s empirical correlation between the measured pulse velocity and bar radius is reviewed and a new correlation is proposed

  16. Reservoir theory, groundwater transit time distributions, and lumped parameter models

    International Nuclear Information System (INIS)

    Etcheverry, D.; Perrochet, P.

    1999-01-01

    The relation between groundwater residence times and transit times is given by the reservoir theory. It allows to calculate theoretical transit time distributions in a deterministic way, analytically, or on numerical models. Two analytical solutions validates the piston flow and the exponential model for simple conceptual flow systems. A numerical solution of a hypothetical regional groundwater flow shows that lumped parameter models could be applied in some cases to large-scale, heterogeneous aquifers. (author)

  17. Pemodelan Markov Switching Dengan Time-varying Transition Probability

    OpenAIRE

    Savitri, Anggita Puri; Warsito, Budi; Rahmawati, Rita

    2016-01-01

    Exchange rate or currency is an economic variable which reflects country's state of economy. It fluctuates over time because of its ability to switch the condition or regime caused by economic and political factors. The changes in the exchange rate are depreciation and appreciation. Therefore, it could be modeled using Markov Switching with Time-Varying Transition Probability which observe the conditional changes and use information variable. From this model, time-varying transition probabili...

  18. Connecting People to Places : Spatiotemporal Analysis of Transit Supply Using Travel Time Cubes

    Science.gov (United States)

    2016-06-01

    Despite its importance, temporal measures of accessibility are rarely used in transit research or practice. This is primarily due to the inherent difficulty and complexity in computing time-based accessibility metrics. Estimating origin-to-destinatio...

  19. The liner shipping berth scheduling problem with transit times

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander; Plum, Christian E.M.; Pisinger, David

    2016-01-01

    In this paper speed optimization of an existing liner shipping network is solved by adjusting the port berth times. The objective is to minimize fuel consumption while retaining the customer transit times including the transhipment times. To avoid too many changes to the time table, changes of port...

  20. Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system.

    Science.gov (United States)

    Worsøe, Jonas; Fynne, Lotte; Gregersen, Tine; Schlageter, Vincent; Christensen, Lisbet A; Dahlerup, Jens F; Rijkhoff, Nico J M; Laurberg, Søren; Krogh, Klaus

    2011-12-29

    Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, φ). Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state. Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1) (p = 0.03). MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

  1. Transitional Leadership: Leadership During Times of Transition, Key Principles, and Considerations for Success.

    Science.gov (United States)

    Norbash, Alexander

    2017-06-01

    To suggest a methodical approach for refining transitional management abilities, including empowerment of a growing leader, leading in an unfamiliar organization or leading in an organization that is changing. Management approaches based on the body of work dealing with leadership studies and transitions and dealing with leadership during times of transition and change management were consolidated and categorized. Transitional leaders can benefit from effective leadership training including defining and prospectively accruing necessary experiences and skills; strengthening information gathering skills; effectively self-assessing; valuing and implementing mentoring; formulating strategy; and communicating. A categorical approach to transitional leadership may be implemented through a systems-based and methodical approach to gaining the definable, and distinct sets of skills and abilities necessary for transitional leadership success. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  2. Uncertainty analysis of power monitoring transit time ultrasonic flow meters

    International Nuclear Information System (INIS)

    Orosz, A.; Miller, D. W.; Christensen, R. N.; Arndt, S.

    2006-01-01

    A general uncertainty analysis is applied to chordal, transit time ultrasonic flow meters that are used in nuclear power plant feedwater loops. This investigation focuses on relationships between the major parameters of the flow measurement. For this study, mass flow rate is divided into three components, profile factor, density, and a form of volumetric flow rate. All system parameters are used to calculate values for these three components. Uncertainty is analyzed using a perturbation method. Sensitivity coefficients for major system parameters are shown, and these coefficients are applicable to a range of ultrasonic flow meters used in similar applications. Also shown is the uncertainty to be expected for density along with its relationship to other system uncertainties. One other conclusion is that pipe diameter sensitivity coefficients may be a function of the calibration technique used. (authors)

  3. Bisimulation and Open Maps for Timed Transition Systems

    DEFF Research Database (Denmark)

    Nielsen, Mogens

    1999-01-01

    Formal models for real-time systems have been studied intensively over the past decade. Much of the theory of untimed systems have been lifted to real-time settings. One example is the notion of bisimulation applied to timed transition systems, which is studied here within the general categorical...

  4. Problems measuring the underground economy in transition

    Czech Academy of Sciences Publication Activity Database

    Hanousek, Jan; Palda, F.

    2006-01-01

    Roč. 14, č. 4 (2006), s. 707-718 ISSN 0967-0750 R&D Projects: GA ČR GA402/04/0166 Institutional research plan: CEZ:AV0Z70850503 Keywords : informal economy * macro estimates of shadow economy * transition Subject RIV: AH - Economics Impact factor: 1.000, year: 2006 http://dx.doi.org/10.1111/j.1468-0351.2006.00268.x

  5. Measurements of traveling transition zone along a superconductor

    International Nuclear Information System (INIS)

    Lottin, J.C.; Miller, J.R.; Lue, J.W.; Dresner, L.

    1978-01-01

    The spatial variation of the temperature in a traveling superconducting-normal transition zone can provide valuable information on transient heat transfer in realistic coil conditions. In this paper, temperature wave curves are presented for several transport currents corresponding to propagation and recovery in a high magnetic field. The temperature profiles have been constructed in the form T = T (x + vt) by measuring the wave velocity and the temperature at one point as a function of time. The temperature is measured directly with differential thermocouples; simultaneous voltage measurements provide a continuous temperature reference in the current sharing region. Information is given about thermocouple calibration in the high magnetic field and about the temperature and magnetic field dependence of the thermal conductivity of the sample

  6. Daylight Saving Time Transitions and Road Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Tuuli Lahti

    2010-01-01

    Full Text Available Circadian rhythm disruptions may have harmful impacts on health. Circadian rhythm disruptions caused by jet lag compromise the quality and amount of sleep and may lead to a variety of symptoms such as fatigue, headache, and loss of attention and alertness. Even a minor change in time schedule may cause considerable stress for the body. Transitions into and out of daylight saving time alter the social and environmental timing twice a year. According to earlier studies, this change in time-schedule leads to sleep disruption and fragmentation of the circadian rhythm. Since sleep deprivation decreases motivation, attention, and alertness, transitions into and out of daylight saving time may increase the amount of accidents during the following days after the transition. We studied the amount of road traffic accidents one week before and one week after transitions into and out of daylight saving time during years from 1981 to 2006. Our results demonstrated that transitions into and out of daylight saving time did not increase the number of traffic road accidents.

  7. Drift-time measurement electronics

    International Nuclear Information System (INIS)

    Pernicka, M.

    1978-01-01

    The aim of the construction was to improve the time resolution without using the facility of time stretching, to have a fast read-out possibility, and to be still cheaper in price in comparison to other systems. A possibility was thus foreseen for using the firm Fairchild. These integrated circuits (IC) have, for example, a propagation delay of 0.75 ns for a gate. One can expect therefore less time jitter and less time difference between the different inputs. Furthermore this IC offers a greater flexibility and therefore the number of ICs decreases and distances become smaller. Working with clock frequencies up to 166.6 MHz is easily possible without running into timing problems. On the other hand, to make full use of the advantages of this IC, it was necessary to build the print as a multilayer. The only risk could be in the use of a completely new product. A further aim was to build for this system a second type of drift-time module with a short time range for measuring drift time and pulse length in rotated multiwire proportional chambers. A brief outline of the specifications of the different modules is given in table 1. (Auth.)

  8. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.

    2012-01-01

    Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods......: The observations were obtained using telescope-defocusing techniques, and achieve a high precision with random errors in the photometry as low as 1mmag per point. To investigate the possibility of TTVs in the light curve, we calculate the overall probability of a TTV signal using Bayesian methods. Results...

  9. No variations in transit times for Qatar-1 b

    Science.gov (United States)

    Maciejewski, G.; Fernández, M.; Aceituno, F. J.; Ohlert, J.; Puchalski, D.; Dimitrov, D.; Seeliger, M.; Kitze, M.; Raetz, St.; Errmann, R.; Gilbert, H.; Pannicke, A.; Schmidt, J.-G.; Neuhäuser, R.

    2015-05-01

    Aims: The transiting hot-Jupiter planet Qatar-1 b exhibits variations in transit times that could be perturbative. A hot Jupiter with a planetary companion on a nearby orbit would constitute an unprecedented planetary configuration, which is important for theories of the formation and evolution of planetary systems. We performed a photometric follow-up campaign to confirm or refute transit timing variations. Methods: We extend the baseline of transit observations by acquiring 18 new transit light curves acquired with 0.6-2.0 m telescopes. These photometric time series, together with data available in the literature, were analyzed in a homogenous way to derive reliable transit parameters and their uncertainties. Results: We show that the dataset of transit times is consistent with a linear ephemeris leaving no hint of any periodic variations with a range of 1 min. We find no compelling evidence of a close-in planetary companion to Qatar-1 b. This finding is in line with a paradigm that hot Jupiters are not components of compact multiplanetary systems. Based on dynamical simulations, we place tighter constraints on the mass of any fictitious nearby planet in the system. Furthermore, new transit light curves allowed us to redetermine system parameters with better precision than reported in previous studies. Our values generally agree with previous determinations. Partly based on (1) data collected with telescopes at the Rozhen National Astronomical Observatory and (2) observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.Tables of light curve data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A109

  10. ASACUSA measures microwave transition in antiprotonic helium

    CERN Document Server

    Eades, John

    2003-01-01

    The ASACUSA collaboration has reinforced its status as a paragon of precision physics by following up its impressive six parts in 10/sup 8/ measurement of the antiproton's charge and mass with new measurements of its magnetism. (4 refs).

  11. Modelling systematics of ground-based transit photometry I. Implications on transit timing variations

    DEFF Research Database (Denmark)

    von Essen, C.; Cellone, S.; Mallonn, M.

    2016-01-01

    introduced a perturbation in the mid-transit times of the hot Jupiter, caused by an Earth-sized planet in a 3:2 mean motion resonance. Analyzing the synthetic light curves produced after certain epochs, we attempt to recover the synthetically added TTV signal by means of usual primary transit fitting...... we attempt to reproduce, by means of physically and empirically motivated relationships, the effects caused by the Earth's atmosphere and the instrumental setup on the synthetic light curves. Therefore, the synthetic data present different photometric quality and transit coverage. In addition, we...

  12. High-Cadence Transit Timing Variation Monitoring of Extrasolar Planets

    Directory of Open Access Journals (Sweden)

    Naef D.

    2011-02-01

    Full Text Available We report ground-based high-cadence transit timing observations of the extrasolar planet WASP-2b. We achieve a typical timing error of 15-30 sec. The data show no significant deviations from the predicted ephemeris.

  13. Relationship between transit time and mechanical properties of a cell through a stenosed microchannel.

    Science.gov (United States)

    Ye, Ting; Shi, Huixin; Phan-Thien, Nhan; Lim, Chwee Teck; Li, Yu

    2018-01-24

    The changes in the mechanical properties of a cell are not only the cause of some diseases, but can also be a biomarker for some disease states. In recent times, microfluidic devices with built-in constrictions have been widely used to measure these changes. The transit time in such devices, defined as the time that a cell takes to pass through a constriction, has been found to be a crucial factor associated with the cell mechanical properties. Here, we use smoothed dissipative particle dynamics (SDPD), a particle-based numerical method, to explore the relationship between the transit time and mechanical properties of a cell. Three expressions of the transit time are developed from our simulation data, with respect to the stenosed size of constrictions, the shear modulus and bending modulus of cells, respectively. We show that a convergent constriction (the inlet is wider than the outlet), and a sharp-corner constriction (the constriction outlet is narrow) are better in identifying the differences in the transit time of cells. Moreover, the transit time increases and gradually approaches a constant as the shear modulus of cells increases, but increases first and then decreases as the bending modulus increases. These results suggest that the mechanical properties of cells can indeed be measured by analyzing their transit time, based on the recommended microfluidic device.

  14. Mean Transit Time and Mean Residence Time for Linear Diffusion–Convection–Reaction Transport System

    Directory of Open Access Journals (Sweden)

    Jacek Waniewski

    2007-01-01

    Full Text Available Characteristic times for transport processes in biological systems may be evaluated as mean transit times (MTTs (for transit states or mean residence times (MRT (for steady states. It is shown in a general framework of a (linear reaction–diffusion–convection equation that these two times are related. Analytical formulas are also derived to calculate moments of exit time distribution using solutions for a stationary state of the system.

  15. Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system

    Directory of Open Access Journals (Sweden)

    WorsØe Jonas

    2011-12-01

    Full Text Available Abstract Background Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. Methods A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4 giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, ϕ. Eight healthy subjects were each investigated three times: (1 with a small magnet mounted on a capsule endoscope (PillCam; (2 with the magnet alone and the small intestine in the fasting state; and (3 with the magnet alone and the small intestine in the postprandial state. Results Experiment (1 showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min and small intestinal transit time (median difference 0.5 min; range: 0-52 min. Comparing experiments (1 and (2 there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2 and (3, short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1 (p = 0.03. Conclusion MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

  16. Measuring health inequalities over time

    Directory of Open Access Journals (Sweden)

    Gustavo Bergonzoli

    2007-11-01

    Full Text Available Background: several methodologies have been used to measure health inequalities. Most of them do so in a cross- sectional fashion, causing significant loss of information. None of them measure health inequalities in social territories over time. Methods: this article presents two approaches measure health inequalities: one approach consists of a refinement of cross-sectional study, by using the analysis of ANOVA variance (ANOVA procedure to explore whether the gap between social territories is real or due to chance. Several adjustments were made to limit errors inevitably found in multiple comparisons. Polynomial procedures were then applied to identify and evaluate any trends. The second sociales se utilizó approach measures the health gap between social territories or strata (as defined in this study over time using the Poisson regression. These approaches were applied using life expectancy and maternal mortality data from Venezuela. Results: a positive relationship between tendenterritories and life expectancy was found, with a significant cia linal trend. The relation between maternal mortality and materna y territorios sociales fue cuadrática. La medición desocial territories was quadratic. The measurement of the la brecha, gap between least developed social territory and the most, a developed territory showed a gap reduction from the first to the second decade, mainly because of an increase of territorio social maternal mortality in the more developed area, rather than a real improvement in the least developed. Conclusions: study helps to clarify the impact that public policies and interventions have in reducing the health gap. Knowledge that a health gap between social territories can decrease without showing improvement in the least developed sector , is an important finding for monitoring and evaluating health interventions for improving living and health conditions in the population.

  17. Esophageal transit time in patients with chagasic megaesophagus

    Science.gov (United States)

    Martins, Paula; Ferreira, Cid Sergio; Cunha-Melo, José Renan

    2018-01-01

    Abstract The aim of this study was to determine the esophageal transit time in control individuals and in chagasic patients with or without megaesophagus. A total of 148 patients were allocated in 6 groups according to serological diagnostic of Chagas disease and the degree of esophageal dilatation: A, control healthy individuals (n = 34, 22.9%); B, indeterminate form (n = 23, 15.5%); C, megaesophagus I (n = 37, 25.0%); D, megaesophagus II (n = 19, 12.8%); E, megaesophagus III (n = 21, 14.2%); and F, megaesophagus IV (n = 14, 9.5%). After 8-hour fasting, patients were asked to swallow 75 mL of barium sulfate solution. x-Rays were obtained after 8, 30, 60, and 90 seconds, 5, 10, 30, 60, and 90 minutes, 2, 6, 12, 24 hours, and at every 12 hours until no more contrast was seen in the esophagus. This was the transit time. The transit time varied from 8 seconds to 36 hours (median = 90 seconds). A linear correlation was observed between transit time and megaesophagus grade: 8 seconds in groups A and B, 5 minutes in C, 30 minutes in D, 2 hours in E, and 9:15 hours in F. Dysphagia was not reported by 60 of 114 (52.6%) patients with positive serological tests for Chagas disease (37/91—40.7%—of patients with megaesophagus I–IV grades). The esophageal transit time increased with the grade of megaesophagus. The esophageal transit time has a direct correlation with the grade of megaesophagus; dysphagia complaint correlates with the grade of megaesophagus. However, many patients with megaesophagus do not report dysphagia. PMID:29517674

  18. Venus Elongation Measurements for the Transit of Venus, using the ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 11. Venus Elongation Measurements for the Transit of Venus, using the Historical Jantar Mantar Observatory. N Rathnasree. Classroom Volume 9 Issue 11 November 2004 pp 46-55 ...

  19. Scintigraphic measurement of colonic transit in patients with idiopathic constipation

    International Nuclear Information System (INIS)

    Yoon, K. H.; Kim, C. K.

    1999-01-01

    To evaluate usefulness of scintigraphic measurement of total and regional colonic transit in patients with idiopathic constipation. 25 patients who were complained chronic constipation underwent scintigraphic measurement of the total and regional colon transit. Of them 10 patients were diagnosed as idiopathic constipation, none of whom had evidence of abnormal function of the pelvic floor. Ten healthy volunteers were also studied. 67 Gallium-labelled Amberlite resin particles were ingested in a coated capsule with methacrylate that dispersed in the ileocecal region. Images were obtained using a gamma camera at regular intervals for the 2, 4, 8, 24, and 48 hours after the initial counting of the radioactivity in the cecum. We determined the geometric center in four regions of interest in the colon (ascending, transverse, descending, and rectosigmoid). Ten patients with colonic inertia showed significant retention of solid residue in the ascending and transverse colon over a 48-hour period. The median values for the healthy subjects at 2, 4, 8, and 24, and 48 hours were 1.44±0.2 (midway through ascending), 1.71±0.45 (midway through transverse), 2.64±0.95 (midway through descending), 3.94±0.89 (midway through rectosigmoid), and 4.52±0.76 (midway through the stool compartment). On the contrary, the values of ten patients with colonic inertia were 1.0±0.0 (midway through ascending), 1.0±0.0 (midway through ascending). 1.02 ±0.06 (midway through ascending), 1.70±0.36 (midway through transverse), and 2.33±0.31(midway through descending) at the same time (p<0.001). In patients with idiopathic constipation is characterized by exaggerated reservoir factions of the ascending and transverse colons. Scintigraphy using 67 Gallium-labelled pellets seems to be a useful tool to demonstrate the delayed colonic transit in patients with colonic inertia

  20. Scintigraphic measurement of colonic transit in patients with idiopathic constipation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, K. H.; Kim, C. K. [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

    1999-07-01

    To evaluate usefulness of scintigraphic measurement of total and regional colonic transit in patients with idiopathic constipation. 25 patients who were complained chronic constipation underwent scintigraphic measurement of the total and regional colon transit. Of them 10 patients were diagnosed as idiopathic constipation, none of whom had evidence of abnormal function of the pelvic floor. Ten healthy volunteers were also studied. 67 Gallium-labelled Amberlite resin particles were ingested in a coated capsule with methacrylate that dispersed in the ileocecal region. Images were obtained using a gamma camera at regular intervals for the 2, 4, 8, 24, and 48 hours after the initial counting of the radioactivity in the cecum. We determined the geometric center in four regions of interest in the colon (ascending, transverse, descending, and rectosigmoid). Ten patients with colonic inertia showed significant retention of solid residue in the ascending and transverse colon over a 48-hour period. The median values for the healthy subjects at 2, 4, 8, and 24, and 48 hours were 1.44{+-}0.2 (midway through ascending), 1.71{+-}0.45 (midway through transverse), 2.64{+-}0.95 (midway through descending), 3.94{+-}0.89 (midway through rectosigmoid), and 4.52{+-}0.76 (midway through the stool compartment). On the contrary, the values of ten patients with colonic inertia were 1.0{+-}0.0 (midway through ascending), 1.0{+-}0.0 (midway through ascending). 1.02 {+-}0.06 (midway through ascending), 1.70{+-}0.36 (midway through transverse), and 2.33{+-}0.31(midway through descending) at the same time (p<0.001). In patients with idiopathic constipation is characterized by exaggerated reservoir factions of the ascending and transverse colons. Scintigraphy using 67 Gallium-labelled pellets seems to be a useful tool to demonstrate the delayed colonic transit in patients with colonic inertia.

  1. Prognosis of constipation: clinical factors and colonic transit time

    Science.gov (United States)

    de Lorijn, F; van Wijk, M P; Reitsma, J; van Ginkel, R; Taminiau, J; Benninga, M

    2004-01-01

    Background: Measurement of colonic transit time (CTT) is sometimes used in the evaluation of patients with chronic constipation. Aim: To investigate the relation between symptoms and CTT, and to assess the importance of symptoms and CTT in predicting outcome. Methods: Between 1995 and 2000, 169 consecutive patients (median age 8.4 years, 65% boys) fulfilling the criteria for constipation were enrolled. During the intervention and follow up period, all kept a diary to record symptoms. CTT was measured at entry to the study. Results: At entry, defecation frequency was lower in girls than in boys, while the frequency of encopresis episodes was higher in boys. CTT values were significantly higher in those with a low defecation frequency (⩽1/week) and a high frequency of encopresis (⩾2/day). However, 50% had CTT values within the normal range. Successful outcome occurred more often in those with a rectal impaction. CTT results 100 hours were less likely to have had a successful outcome. Conclusion: The presence of a rectal impaction at presentation is associated with a better outcome at one year. A CTT >100 hours is associated with a poor outcome at one year. PMID:15269069

  2. Transit timing observations from Kepler. VI. Potentially interesting candidate systems from fourier-based statistical tests

    DEFF Research Database (Denmark)

    Steffen, J.H.; Ford, E.B.; Rowe, J.F.

    2012-01-01

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify...... several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies....

  3. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VI. POTENTIALLY INTERESTING CANDIDATE SYSTEMS FROM FOURIER-BASED STATISTICAL TESTS

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Ford, Eric B.; Rowe, Jason F.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Jenkins, Jon M.; Koch, David G.; Sanderfer, Dwight T.; Seader, Shawn; Twicken, Joseph D.; Fabrycky, Daniel C.; Holman, Matthew J.; Welsh, William F.; Batalha, Natalie M.; Ciardi, David R.; Kjeldsen, Hans; Prša, Andrej

    2012-01-01

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies.

  4. Pixel-by-pixel mean transit time without deconvolution.

    Science.gov (United States)

    Dobbeleir, Andre A; Piepsz, Amy; Ham, Hamphrey R

    2008-04-01

    Mean transit time (MTT) within a kidney is given by the integral of the renal activity on a well-corrected renogram between time zero and time t divided by the integral of the plasma activity between zero and t, providing that t is close to infinity. However, as the data acquisition of a renogram is finite, the MTT calculated using this approach might result in the underestimation of the true MTT. To evaluate the degree of this underestimation we conducted a simulation study. One thousand renograms were created by convoluting various plasma curves obtained from patients with different renal clearance levels with simulated retentions curves having different shapes and mean transit times. For a 20 min renogram, the calculated MTT started to underestimate the MTT when the MTT was higher than 6 min. The longer the MTT, the greater was the underestimation. Up to a MTT value of 6 min, the error on the MTT estimation is negligible. As normal cortical transit is less than 2 min, this approach is used for patients to calculate pixel-to-pixel cortical mean transit time and to create a MTT parametric image without deconvolution.

  5. Computation of transit times using the milestoning method with applications to polymer translocation

    Science.gov (United States)

    Hawk, Alexander T.; Konda, Sai Sriharsha M.; Makarov, Dmitrii E.

    2013-08-01

    Milestoning is an efficient approximation for computing long-time kinetics and thermodynamics of large molecular systems, which are inaccessible to brute-force molecular dynamics simulations. A common use of milestoning is to compute the mean first passage time (MFPT) for a conformational transition of interest. However, the MFPT is not always the experimentally observed timescale. In particular, the duration of the transition path, or the mean transit time, can be measured in single-molecule experiments, such as studies of polymers translocating through pores and fluorescence resonance energy transfer studies of protein folding. Here we show how to use milestoning to compute transit times and illustrate our approach by applying it to the translocation of a polymer through a narrow pore.

  6. Caregivers' Playfulness and Infants' Emotional Stress during Transitional Time

    Science.gov (United States)

    Jung, Jeesun

    2011-01-01

    The purpose of this study is to explore the playfulness of the teachers of infants and its relations to infants' emotional distress during the transitional time at a child care centre. The study used a qualitative case study. Two infant caregivers in a university-based child care centre participated in this study. For the three-month research…

  7. Real-time rescheduling and disruption management for public transit

    NARCIS (Netherlands)

    Lai, D.S.W.; Leung, Janny M.Y.

    2017-01-01

    This research is motivated by the operations of a public transit company in Hong Kong. We investigate how real-time information can be utilized in combination with historical data to improve routing and scheduling decisions practically. A dynamic integrated vehicle and crew scheduling problem is

  8. Time delay between cardiac and brain activity during sleep transitions

    NARCIS (Netherlands)

    Long, X.; Arends, J.B.A.M.; Aarts, R.M.; Haakma, R.; Fonseca, P.; Rolink, J.

    2015-01-01

    Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by

  9. Room acoustic transition time based on reflection overlap

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Brunskog, Jonas; Jacobsen, Finn

    2010-01-01

    A transition time is defined based on the temporal overlap of reflected pulses in room impulse responses. Assuming specular reflections only, the temporal distance between adjacent reflections, which is proportional to the volume of a room, is compared with the characteristic width of a pulse at ...... in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions....

  10. Room acoustic transition time based on reflection overlap

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Brunskog, Jonas; Jacobsen, Finn

    2013-01-01

    A transition time is defined based on the temporal overlap of reflected pulses in room impulse responses. Assuming specular reflections only, the temporal distance between adjacent reflections, which is proportional to the volume of a room, is compared with the characteristic width of a pulse at ...... in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions....

  11. Oro-cecal transit time : influence of a subsequent meal

    NARCIS (Netherlands)

    Priebe, MG; Wachters-Hagedoorn, RE; Stellaard, F; Heiner, AM; Elzinga, H; Vonk, RJ

    Background Small intestinal and oro-cecal transit time (OCTT) is determined for clinical diagnostics and research purposes. Experimental protocols used vary with respect to the inclusion of a subsequent meal during the test period. This study was conducted to elucidate whether the ingestion of a

  12. Part-time Labor, Work Rules, and Transit Costs

    Science.gov (United States)

    1981-01-01

    This report examines two major issues: (1)the impact of labor union work rules : on bus transit operating costs and (2)the magnitude of cost savings that can be : expected from the use of part-time drivers. These issues are examined within : the cont...

  13. Finite-time quantum-to-classical transition for a Schroedinger-cat state

    International Nuclear Information System (INIS)

    Paavola, Janika; Hall, Michael J. W.; Paris, Matteo G. A.; Maniscalco, Sabrina

    2011-01-01

    The transition from quantum to classical, in the case of a quantum harmonic oscillator, is typically identified with the transition from a quantum superposition of macroscopically distinguishable states, such as the Schroedinger-cat state, into the corresponding statistical mixture. This transition is commonly characterized by the asymptotic loss of the interference term in the Wigner representation of the cat state. In this paper we show that the quantum-to-classical transition has different dynamical features depending on the measure for nonclassicality used. Measures based on an operatorial definition have well-defined physical meaning and allow a deeper understanding of the quantum-to-classical transition. Our analysis shows that, for most nonclassicality measures, the Schroedinger-cat state becomes classical after a finite time. Moreover, our results challenge the prevailing idea that more macroscopic states are more susceptible to decoherence in the sense that the transition from quantum to classical occurs faster. Since nonclassicality is a prerequisite for entanglement generation our results also bridge the gap between decoherence, which is lost only asymptotically, and entanglement, which may show a ''sudden death''. In fact, whereas the loss of coherences still remains asymptotic, we emphasize that the transition from quantum to classical can indeed occur at a finite time.

  14. Assessment of colonic transit time using MRI: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann, Sonja; Reiser, Maximilian F.; Lienemann, Andreas [Ludwig-Maximilians-University, Department of Clinical Radiology, Campus Grosshadern, Munich (Germany); Kirchhoff, Chlodwig; Ladurner, Roland; Mussack, Thomas [Ludwig-Maximilians-University, Department of Surgery and Traumatology, Campus Innenstadt, Munich (Germany)

    2007-03-15

    The aim of this pilot study was to evaluate a new, non-invasive examination method using MRI for the quantification of the colonic transit time after oral administration of gadolinium-saline solution filled capsules. Healthy volunteers without previous or acute symptoms of gastrointestinal disorders were enrolled. After a 3-day diet for the standardization of gastrocolonic content the volunteers swallowed five Gd-DTPA/saline 0.9%-filledcapsules. Seven different concentrations of Gd-DTPA/saline 0.9% solution between 1:0 and 0:1 were tested in a dilution series. Following ingestion of capsules, coronal Flash T1 and True Fisp sequences using a 1.5 Tesla system were obtained at 0 h, 3 h, 6 h, 12 h, 24 h, 36 h and 60 h. Sequences were analyzed by two independent experts for locating the capsules. Overall colonic transit time was separately analyzed for both genders. Fifteen healthy volunteers (7 females, 8 males; mean age 34{+-}13 years) were enrolled. The phantom study provided the best contrast in both the T1-and T2-weighted sequences defining a ratio of 1:10 for Gd-DTPA/saline 0.9% solution. The mean transit time accounted for 41{+-}9 h in women and for 31{+-}10 h in men. MRI is an adequate method for the assessment of colonic transit time offering the advantages of no exposure to radiation, short examination time, possible dynamic evaluation of the transit and the practicability in terms of a future adoption to clinical routine. (orig.)

  15. Assessment of colonic transit time using MRI: a feasibility study

    International Nuclear Information System (INIS)

    Buhmann, Sonja; Reiser, Maximilian F.; Lienemann, Andreas; Kirchhoff, Chlodwig; Ladurner, Roland; Mussack, Thomas

    2007-01-01

    The aim of this pilot study was to evaluate a new, non-invasive examination method using MRI for the quantification of the colonic transit time after oral administration of gadolinium-saline solution filled capsules. Healthy volunteers without previous or acute symptoms of gastrointestinal disorders were enrolled. After a 3-day diet for the standardization of gastrocolonic content the volunteers swallowed five Gd-DTPA/saline 0.9%-filledcapsules. Seven different concentrations of Gd-DTPA/saline 0.9% solution between 1:0 and 0:1 were tested in a dilution series. Following ingestion of capsules, coronal Flash T1 and True Fisp sequences using a 1.5 Tesla system were obtained at 0 h, 3 h, 6 h, 12 h, 24 h, 36 h and 60 h. Sequences were analyzed by two independent experts for locating the capsules. Overall colonic transit time was separately analyzed for both genders. Fifteen healthy volunteers (7 females, 8 males; mean age 34±13 years) were enrolled. The phantom study provided the best contrast in both the T1-and T2-weighted sequences defining a ratio of 1:10 for Gd-DTPA/saline 0.9% solution. The mean transit time accounted for 41±9 h in women and for 31±10 h in men. MRI is an adequate method for the assessment of colonic transit time offering the advantages of no exposure to radiation, short examination time, possible dynamic evaluation of the transit and the practicability in terms of a future adoption to clinical routine. (orig.)

  16. Transition in adolescents across time, disease and gender

    DEFF Research Database (Denmark)

    Aagaard, Hanne; Ludvigsen, Mette Spliid; Svanholm, Jette Rolf

    interview with the adolescent at outpatient clinics at Aarhus University Hospital. Follow-up is planned at 15 and 18 years of age. A comparative approach is employed to show central characteristics across time, disease and gender. Results: Results from analysis inspired by Ricoeur's phenomenological......Background: Despite a growing number of studies on transition to adulthood in adolescents, literature is scarce on qualitative, longitudinal studies of transitions in adolescents with severe chronic diseases. The aim is to study transition in adolescents with cystic fibrosis, congenital heart...... diseases and chronic kidney diseases. We specifically focus on the adolescents’ experiences, 'what is important to them', 'what characterises their interaction with health care staff' and 'the communication between the adolescents and health care staff as perceived by the adolescents'. Methods...

  17. Time delay between cardiac and brain activity during sleep transitions

    Science.gov (United States)

    Long, Xi; Arends, Johan B.; Aarts, Ronald M.; Haakma, Reinder; Fonseca, Pedro; Rolink, Jérôme

    2015-04-01

    Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by electroencephalographic (EEG) mean frequency and the cardiac parameters included heart rate, standard deviation of heartbeat intervals, and their low- and high-frequency spectral powers. Using a cross-correlation analysis, we found that the cardiac variations during wake-sleep and NREM sleep transitions preceded the EEG changes by 1-3 min but this was not the case for REM sleep transitions. These important findings can be further used to predict the onset and ending of some sleep stages in an early manner.

  18. Dual-Priced Modal Transition Systems with Time Durations

    DEFF Research Database (Denmark)

    Beneš, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

    2012-01-01

    Modal transition systems are a well-established specification formalism for a high-level modelling of component-based software systems. We present a novel extension of the formalism called modal transition systems with durations where time durations are modelled as controllable or uncontrollable...... intervals. We further equip the model with two kinds of quantitative aspects: each action has its own running cost per time unit, and actions may require several hardware components of different costs. We ask the question, given a fixed budget for the hardware components, what is the implementation...... with the cheapest long-run average reward. We give an algorithm for computing such optimal implementations via a reduction to a new extension of mean payoff games with time durations and analyse the complexity of the algorithm....

  19. Integrated response and transit time distributions of watersheds by combining hydrograph separation and long-term transit time modeling

    Directory of Open Access Journals (Sweden)

    M. C. Roa-García

    2010-08-01

    Full Text Available We present a new modeling approach analyzing and predicting the Transit Time Distribution (TTD and the Response Time Distribution (RTD from hourly to annual time scales as two distinct hydrological processes. The model integrates Isotope Hydrograph Separation (IHS and the Instantaneous Unit Hydrograph (IUH approach as a tool to provide a more realistic description of transit and response time of water in catchments. Individual event simulations and parameterizations were combined with long-term baseflow simulation and parameterizations; this provides a comprehensive picture of the catchment response for a long time span for the hydraulic and isotopic processes. The proposed method was tested in three Andean headwater catchments to compare the effects of land use on hydrological response and solute transport. Results show that the characteristics of events and antecedent conditions have a significant influence on TTD and RTD, but in general the RTD of the grassland dominated catchment is concentrated in the shorter time spans and has a higher cumulative TTD, while the forest dominated catchment has a relatively higher response distribution and lower cumulative TTD. The catchment where wetlands concentrate shows a flashier response, but wetlands also appear to prolong transit time.

  20. Quantum Zeno and anti-Zeno effects measured by transition probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenxian, E-mail: wxzhang@whu.edu.cn [School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072 (China); Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); CEMS, RIKEN, Saitama 351-0198 (Japan); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Kofman, A.G. [CEMS, RIKEN, Saitama 351-0198 (Japan); Department of Physics, The University of Michigan, Ann Arbor, MI 48109-1040 (United States); Zhuang, Jun [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); You, J.Q. [Beijing Computational Science Research Center, Beijing 10084 (China); Department of Physics, Fudan University, Shanghai 200433 (China); CEMS, RIKEN, Saitama 351-0198 (Japan); Nori, Franco [CEMS, RIKEN, Saitama 351-0198 (Japan); Department of Physics, The University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2013-10-30

    Using numerical calculations, we compare the transition probabilities of many spins in random magnetic fields, subject to either frequent projective measurements, frequent phase modulations, or a mix of modulations and measurements. For various distribution functions, we find the transition probability under frequent modulations is suppressed most if the pulse delay is short and the evolution time is larger than a critical value. Furthermore, decay freezing occurs only under frequent modulations as the pulse delay approaches zero. In the large pulse-delay region, however, the transition probabilities under frequent modulations are highest among the three control methods.

  1. Watching excitons move: the time-dependent transition density matrix

    Science.gov (United States)

    Ullrich, Carsten

    2012-02-01

    Time-dependent density-functional theory allows one to calculate excitation energies and the associated transition densities in principle exactly. The transition density matrix (TDM) provides additional information on electron-hole localization and coherence of specific excitations of the many-body system. We have extended the TDM concept into the real-time domain in order to visualize the excited-state dynamics in conjugated molecules. The time-dependent TDM is defined as an implicit density functional, and can be approximately obtained from the time-dependent Kohn-Sham orbitals. The quality of this approximation is assessed in simple model systems. A computational scheme for real molecular systems is presented: the time-dependent Kohn-Sham equations are solved with the OCTOPUS code and the time-dependent Kohn-Sham TDM is calculated using a spatial partitioning scheme. The method is applied to show in real time how locally created electron-hole pairs spread out over neighboring conjugated molecular chains. The coupling mechanism, electron-hole coherence, and the possibility of charge separation are discussed.

  2. Biomagnetic techniques for evaluating gastric emptying, peristaltic contraction and transit time.

    Science.gov (United States)

    la Roca-Chiapas, Jose María De; Cordova-Fraga, Teodoro

    2011-10-15

    Biomagnetic techniques were used to measure motility in various parts of the gastrointestinal (GI) tract, particularly a new technique for detecting magnetic markers and tracers. A coil was used to enhance the signal from a magnetic tracer in the GI tract and the signal was detected using a fluxgate magnetometer or a magnetoresistor in an unshielded room. Estimates of esophageal transit time were affected by the position of the subject. The reproducibility of estimates derived using the new biomagnetic technique was greater than 85% and it yielded estimates similar to those obtained using scintigraphy. This technique is suitable for studying the effect of emotional state on GI physiology and for measuring GI transit time. The biomagnetic technique can be used to evaluate digesta transit time in the esophagus, stomach and colon, peristaltic frequency and gastric emptying and is easy to use in the hospital setting.

  3. Measuring magnetic field vector by stimulated Raman transitions

    International Nuclear Information System (INIS)

    Wang, Wenli; Wei, Rong; Lin, Jinda; Wang, Yuzhu; Dong, Richang; Zou, Fan; Chen, Tingting

    2016-01-01

    We present a method for measuring the magnetic field vector in an atomic fountain by probing the line strength of stimulated Raman transitions. The relative line strength for a Λ-type level system with an existing magnetic field is theoretically analyzed. The magnetic field vector measured by our proposed method is consistent well with that by the traditional bias magnetic field method with an axial resolution of 6.1 mrad and a radial resolution of 0.16 rad. Dependences of the Raman transitions on laser polarization schemes are also analyzed. Our method offers the potential advantages for magnetic field measurement without requiring additional bias fields, beyond the limitation of magnetic field intensity, and extending the spatial measurement range. The proposed method can be widely used for measuring magnetic field vector in other precision measurement fields.

  4. Transic time measures in scattering theory

    International Nuclear Information System (INIS)

    MacMillan, L.W.; Osborn, T.A.

    1980-01-01

    This paper studies the time evolution of state vectors that are the solutions of the time-dependent Schroedinger equation, characterized by a Hamiltonian h. We employ trace-theorem methods to prove that the transit time of state vectors through a finite space region, Σ, may be used to construct a family in the energy variable, epsilon, of unique, positive, trace-class operators. The matrix elements of these operators, give the transit time of any vector through Σ, It is proved that the trace of these operators, for a fixed energy epsilon, provide a function which simultaneously gives the sum of all orbital transit times through region Σ and represents the state density of all vectors that have support on Σ and energy epsilon. We use the transit-time operators to recover the usual theory of time delay for single-channel scattering systems. In the process we extend the known results on time delay to include scattering by fixed impurities in a periodic medium

  5. Assessment of chronic constipation: colon transit time versus defecography

    International Nuclear Information System (INIS)

    Prokesch, R.W.; Breitenseher, M.J.; Kettenbach, J.; Herbst, F.; Maier, A.; Lechner, G.; Mahieu, P.

    1999-01-01

    Objective: The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. Materials and methods: In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. Results: Group I, idiopathic constipation (n=11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n=10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n=9), rectal prolapse (n=5) or spastic pelvic floor syndrome (n=4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P<0.05). Conclusion: The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG

  6. Assessment of chronic constipation: colon transit time versus defecography

    Energy Technology Data Exchange (ETDEWEB)

    Prokesch, R.W. E-mail: rupert.prokesch@univie.ac.at; Breitenseher, M.J.; Kettenbach, J.; Herbst, F.; Maier, A.; Lechner, G.; Mahieu, P

    1999-12-01

    Objective: The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. Materials and methods: In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. Results: Group I, idiopathic constipation (n=11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n=10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n=9), rectal prolapse (n=5) or spastic pelvic floor syndrome (n=4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P<0.05). Conclusion: The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG.

  7. Transit time spreads in biased paracentric hemispherical deflection analyzers

    International Nuclear Information System (INIS)

    Sise, Omer; Zouros, Theo J.M.

    2016-01-01

    The biased paracentric hemispherical deflection analyzers (HDAs) are an alternative to conventional (centric) HDAs maintaining greater dispersion, lower angular aberrations, and hence better energy resolution without the use of any additional fringing field correctors. In the present work, the transit time spread of the biased paracentric HDA is computed over a wide range of analyzer parameters. The combination of high energy resolution with good time resolution and simplicity of design makes the biased paracentric analyzers very promising for both coincidence and singles spectroscopy applications.

  8. Transit time spreads in biased paracentric hemispherical deflection analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Sise, Omer, E-mail: omersise@sdu.edu.tr [Dept. of Science Education, Faculty of Education, Suleyman Demirel Univ., 32260 Isparta (Turkey); Zouros, Theo J.M. [Dept. of Physics, Univ. of Crete, P.O. Box 2208, GR 71003 Heraklion (Greece); Tandem Lab, INPP, NCSR Demokritos, P.O. Box 60228, GR 15310 Ag. Paraskevi (Greece)

    2016-02-15

    The biased paracentric hemispherical deflection analyzers (HDAs) are an alternative to conventional (centric) HDAs maintaining greater dispersion, lower angular aberrations, and hence better energy resolution without the use of any additional fringing field correctors. In the present work, the transit time spread of the biased paracentric HDA is computed over a wide range of analyzer parameters. The combination of high energy resolution with good time resolution and simplicity of design makes the biased paracentric analyzers very promising for both coincidence and singles spectroscopy applications.

  9. Transit time spreads in biased paracentric hemispherical deflection analyzers

    Science.gov (United States)

    Sise, Omer; Zouros, Theo J. M.

    2016-02-01

    The biased paracentric hemispherical deflection analyzers (HDAs) are an alternative to conventional (centric) HDAs maintaining greater dispersion, lower angular aberrations, and hence better energy resolution without the use of any additional fringing field correctors. In the present work, the transit time spread of the biased paracentric HDA is computed over a wide range of analyzer parameters. The combination of high energy resolution with good time resolution and simplicity of design makes the biased paracentric analyzers very promising for both coincidence and singles spectroscopy applications.

  10. Measurement of transitional flow in pipes using ultrasonic flowmeters

    Energy Technology Data Exchange (ETDEWEB)

    Zheng-Gang, Liu; Guang-Sheng, Du; Zhu-Feng, Shao; Qian-Ran, He; Chun-Li, Zhou, E-mail: lzhenggang@sdu.edu.cn [School of Energy and Power Engineering, Qian-Fo-shan campus, Shandong University, Jinan City 250061, Shandong Province (China)

    2014-10-01

    The accuracy of an ultrasonic flowmeter depends on the ratio k of average profile velocity of pipe and average velocity of an ultrasonic propagation path. But there is no appropriate method of calculating k for transition flow. In this paper, the velocity field of the transition flow in a pipe is measured by particle image velocimetry. On this basis, the k of U-shaped and V-shaped ultrasonic flowmeter is obtained when Reynolds number is between 2000 and 20 000. It is shown that the k is constant when the Reynolds number is in the range of 2000–2400 and 5400–20 000, and the k decreases with the increasing of Re when the Reynolds number is 2400–5400. The results of study can be used to improve the measurement accuracy of ultrasonic flowmeters when flow is transition flow and can provide help for the study of pipe flow. (paper)

  11. Recovery Temperature, Transition, and Heat Transfer Measurements at Mach 5

    Science.gov (United States)

    Brinich, Paul F.

    1961-01-01

    Schlieren, recovery temperature, and heat-transfer measurements were made on a hollow cylinder and a cone with axes alined parallel to the stream. Both the cone and cylinder were equipped with various bluntnesses, and the tests covered a Reynolds number range up to 20 x 10(exp 6) at a free-stream Mach number of 4.95 and wall to free-stream temperature ratios from 1.8 to 5.2 (adiabatic). A substantial transition delay due to bluntness was found for both the cylinder and the cone. For the present tests (Mach 4.95), transition was delayed by a factor of 3 on the cylinder and about 2 on the cone, these delays being somewhat larger than those observed in earlier tests at Mach 3.1. Heat-transfer tests on the cylinder showed only slight effects of wall temperature level on transition location; this is to be contrasted to the large transition delays observed on conical-type bodies at low surface temperatures at Mach 3.1. The schlieren and the peak-recovery-temperature methods of detecting transition were compared with the heat-transfer results. The comparison showed that the first two methods identified a transition point which occurred just beyond the end of the laminar run as seen in the heat-transfer data.

  12. Optimizing the search for transiting planets in long time series

    Science.gov (United States)

    Ofir, Aviv

    2014-01-01

    Context. Transit surveys, both ground- and space-based, have already accumulated a large number of light curves that span several years. Aims: The search for transiting planets in these long time series is computationally intensive. We wish to optimize the search for both detection and computational efficiencies. Methods: We assume that the searched systems can be described well by Keplerian orbits. We then propagate the effects of different system parameters to the detection parameters. Results: We show that the frequency information content of the light curve is primarily determined by the duty cycle of the transit signal, and thus the optimal frequency sampling is found to be cubic and not linear. Further optimization is achieved by considering duty-cycle dependent binning of the phased light curve. By using the (standard) BLS, one is either fairly insensitive to long-period planets or less sensitive to short-period planets and computationally slower by a significant factor of ~330 (for a 3 yr long dataset). We also show how the physical system parameters, such as the host star's size and mass, directly affect transit detection. This understanding can then be used to optimize the search for every star individually. Conclusions: By considering Keplerian dynamics explicitly rather than implicitly one can optimally search the BLS parameter space. The presented Optimal BLS enhances the detectability of both very short and very long period planets, while allowing such searches to be done with much reduced resources and time. The Matlab/Octave source code for Optimal BLS is made available. The MATLAB code is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/561/A138

  13. Defaecation disorders in children, colonic transit time versus the Barr-score

    NARCIS (Netherlands)

    Benninga, M. A.; Büller, H. A.; Staalman, C. R.; Gubler, F. M.; Bossuyt, P. M.; van der Plas, R. N.; Taminiau, J. A.

    1995-01-01

    It is still unclear how to evaluate the existence of faecal retention or impaction in children with defaecation disorders. To objectivate the presence and degree of constipation we measured segmental and total colonic transit times (CTT) using radio-opaque markers in 211 constipated children. On

  14. Validation of a 1-mm transit time flow probe and the potential for use in microsurgery

    DEFF Research Database (Denmark)

    Bonde, Christian T; Elberg, Jens J; Holstein-Rathlou, N.-H.

    2006-01-01

    The objective of this study was to validate a prototype transit time ultrasound flow probe (Medi-Stim Butterfly Flowmeter BF 2004) of only 1 mm and to evaluate its potential for use in microsurgery. Knowledge of the ability of this kind of system to measure flow in small vessels and at small flow...

  15. A search for transit timing variations and orbital decay in WASP-46b

    Science.gov (United States)

    Petrucci, R.; Jofré, E.; Ferrero, L. V.; Cúneo, V.; Saker, L.; Lovos, F.; Gómez, M.; Mauas, P.

    2018-02-01

    We present 12 new transit observations of the exoplanet WASP-46b obtained with the 1.54-m telescope at Estación Astrofísica de Bosque Alegre (EABA, Argentina) and the 0.40-m Horacio Ghielmetti and 2.15-m Jorge Sahade telescopes at Complejo Astronómico El Leoncito (CASLEO, Argentina). We analyse them together with 37 light curves from the literature to re-determine the physical parameters and search for additional planets via transit timing variations (TTVs). We consider the 31 transits with uncertainties in their mid-transit times (e_T0) activity could be affecting the measured mid-transit times. This value of dispersion allows us to rule out the presence of additional bodies with masses larger than 2.3, 4.6, 7 and 9.3 M_{\\oplus} at the first-order mean-motion resonances 2:1, 3:2, 4:3 and 5:4 with the transiting planet, respectively. Despite the 6 yr baseline and a typical light-curve precision of 2 × 10-3, we find that we cannot significantly demonstrate a slow decrease of the orbital period of WASP-46b. We place a lower limit of Q⋆ > 7 × 103 on the tidal quality factor and determine that an additional 6 yr baseline is required to rule out Q⋆ < 105.

  16. 7 key measures for France to enter energy transition

    International Nuclear Information System (INIS)

    Creach, Morgane; Vandaele, Diane; Richard, Marion; Fink, Meike; Quirion, Philippe; Bonduelle, Antoine; Berthier, Julien; Mossalgue, Marc; Louchard, Olivier; Lenoir, Didier; Vormus, Joel; Charru, Madeleine; Claustre, Raphael; Mathis, Paul; Gauthier, Raphaelle; Couturier, Christian; Mijeon, Charlotte; Gavand, Karine; Majnoni d'Intignano, Sophia; Delcroix, Julie

    2012-01-01

    The authors of this report propose, describe and discuss seven measures to be taken to promote and support energy transition in France: to introduce a climate-energy contribution, to adopt a law for a progressive and complete nuclear phasing out, to set local communities at the heart of energy transition, to introduce a mandatory thermal renewal of existing buildings, to develop a less greenhouse gas emitter agricultural model, to enter into a low-carbon and energy efficient transport infrastructure scheme, and to plan the struggle against urban sprawl at the scale of the living area

  17. Comparison of L-H transition measurements with physics models

    International Nuclear Information System (INIS)

    Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.; Leonard, A.W.; Osborne, T.H.; Thomas, D.M.

    1998-12-01

    A technique of fitting a modified hyperbolic tangent to the edge profiles has improved the localization of plasma edge parameters. Non-dimensional edge parameters are broadly consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. The dramatic change of power threshold with the direction of the ion ∇B drift implies that phenomena in the divertor region may be critical for the L-H transition

  18. TRANSIT TIMING VARIATIONS FOR INCLINED AND RETROGRADE EXOPLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

    2010-01-01

    We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0 deg. 170 deg. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45 deg., becoming approximately constant for 45 deg. 135 deg. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0 deg. to 180 deg., whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135 deg. < i ≤ 180 deg.), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

  19. Photoperiodic time measurement in insects

    Czech Academy of Sciences Publication Activity Database

    Doležel, David

    2015-01-01

    Roč. 7, Feb 02 (2015), s. 98-103 ISSN 2214-5745 R&D Projects: GA ČR GC14-32654J; GA MŠk LH14029 Institutional support: RVO:60077344 Keywords : photoperiodic time Subject RIV: ED - Physiology Impact factor: 2.719, year: 2015 http://www.sciencedirect.com/science/article/pii/S2214574514001576

  20. Dual-phase helical CT using bolus triggering technique: optimization of transition time

    International Nuclear Information System (INIS)

    Choi, Young Ho; Kim, Tae Kyoung; Park, Byung Kwan; Koh, Young Hwan; Han, Joon Koo; Choi, Byung Ihn

    1999-01-01

    To optimize the transition time between the triggering point in monitoring scanning and the initiation of diagnostic hepatic arterial phase (HAP) scanning in hepatic spiral CT, using a bolus triggering technique. One hundred consecutive patients with focal hepatic lesion were included in this study. Patients were randomized into two groups. Transition times of 7 and 11 seconds were used in group 1 and 2, respectively. In all patients, bolus triggered HAP spiral CT was obtained using a semi-automatic bolus tracking program after the injection of 120mL of non-ionic contrast media at a rate of 3mL/sec. When aortic enhancement reached 90 HU, diagnostic HAP scanning began after a given transition time. From images of group 1 and group 2, the degree of parenchymal enhancement of the liver and tumor-to-liver attenuation difference were measured. Also, for qualitative analysis, conspicuity of the hepatic artery and hypervascular tumor was scored and analyzed. Hepatic parenchymal enhancement on HAP was 12.07 + /-6.44 HU in group 1 and 16.03 + /-5.80 HU in group 2 (p .05). In the evaluation of conspicuity of hepatic artery, there was no statistically significant difference between the two groups (p > .05). The conspicuity of hypervascular tumors in group 2 was higher than in group 1 (p < .05). HAP spiral CT using a bolus triggering technique with a transition time of 11 seconds provides better HAP images than when the transition time is 7 seconds

  1. Comparison of L-H transition measurements with physics models

    International Nuclear Information System (INIS)

    Carlstrom, T.N.; Burrell, K.H.; Carreras, B.A.

    1999-01-01

    Sawteeth and neutrals are found to have a significant influence on the H-mode power threshold scaling. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. Since the power threshold changes dramatically with the direction of the ion ∇B drift, this implies that phenomena in the divertor region are critical for the L-H transition. Local conditions at the plasma edge are consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. However, scatter in the database is too large to distinguish between conditions that lead to an L-H transition and those that remain in L-mode. (author)

  2. Comparison of L-H transition measurements with physics models

    International Nuclear Information System (INIS)

    Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.

    2001-01-01

    Sawteeth and neutrals are found to have a significant influence on the H-mode power threshold scaling. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. Since the power threshold changes dramatically with the direction of the ion ∇B drift, this implies that phenomena in the divertor region are critical for the L-H transition. Local conditions at the plasma edge are consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. However, scatter in the database is too large to distinguish between conditions that lead to an L-H transition and those that remain in L-mode. (author)

  3. Determination of global and regional heart functions with minimum transit times

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; Becker, V.; Vyska, K.; Freundlieb, C.; Bosiljanoff, P.

    1980-01-01

    The minimum transit time obviously represents the most constant flow parameter. By means of a constant, that was chosen to be 1.2 for cardiac flow, it is equal to the quotient of volume to flow and is also inversely related proportional to the fraction of ejection that is concerned. The first indicator passage through the heart is measured for the minimum cardiac transit time, whereby interesting regions were chosen for the two auricula, the two ventricula, the pulmonary artery and the aorta. The time activity characteristica obtained from the particular regions need a special smoothing by means of the gliding mean, so that the arrival times can easily be recognized. This way in one examination process the differences of arrival times respectively the minimal transit times can be obtained for each particular cardiac segment, the pulmonary circuit and the whole cardio-pulmonary circuit. The advantages of minimum cardiac transit time measurements are the simplicity and the speed of the noninvasive functional diagnostic with lower radiation load and accuracy and reproductability with low error limits, especially for the whole cardio-pulmonary MTT. The simultaneous acquisition of multiple cardiac segments is to emphasize a special way. For its particular values similar error widths were found as for the left ventricular function measurement with the triggered scintigraphy of the interior of the heart. A further advantage of the measurement is an almost problem-less application in body load. Therefore the MTT-measurement is especially useful for preventive diagnostics of coronary diseases. A combination of MTT-measurements of all segments of the small circuit with the triggered scintigraphy of the interior of the heart for analysis of regional left-ventricular ejection fractions and left-ventricular wall movements would essentially enrich the noninvasive cardiac diagnostics. (orig./APR) [de

  4. Time-dependent reflection at the localization transition

    Science.gov (United States)

    Skipetrov, Sergey E.; Sinha, Aritra

    2018-03-01

    A short quasimonochromatic wave packet incident on a semi-infinite disordered medium gives rise to a reflected wave. The intensity of the latter decays as a power law, 1 /tα , in the long-time limit. Using the one-dimensional Aubry-André model, we show that in the vicinity of the critical point of Anderson localization transition, the decay slows down, and the power-law exponent α becomes smaller than both α =2 found in the Anderson localization regime and α =3 /2 expected for a one-dimensional random walk of classical particles.

  5. Analysis of transit time spread on FBK silicon photomultipliers

    International Nuclear Information System (INIS)

    Acerbi, F.; Gola, A.; Ferri, A.; Zorzi, N.; Paternoster, G.; Piemonte, C.

    2015-01-01

    In this paper we studied one of the aspects potentially limiting the single-photon time-resolution (SPTR) of the silicon photomultiplier (SiPM): the transit time spread (TTS). We illuminated the SiPM in different positions with a fast-pulsed laser collimated to a circular spot of 0.2 mm-diameter and acquired bi-dimensional maps of the avalanche-signal arrival time of RGB and RGB-HD SiPMs, produced at FBK. We studied the effect of both the number of bonding wires connecting the device to the package and the layout of the top-metal connection (on the device). We found that the TTS does not simply depend on the trace length between the cell and the bonding pad and it could vary in the range between tens of picoseconds (with 3 bonding connections) to more than one hundred of picoseconds (with one connection)

  6. Transit time dispersion in pulmonary and systemic circulation: effects of cardiac output and solute diffusivity.

    Science.gov (United States)

    Weiss, Michael; Krejcie, Tom C; Avram, Michael J

    2006-08-01

    We present an in vivo method for analyzing the distribution kinetics of physiological markers into their respective distribution volumes utilizing information provided by the relative dispersion of transit times. Arterial concentration-time curves of markers of the vascular space [indocyanine green (ICG)], extracellular fluid (inulin), and total body water (antipyrine) measured in awake dogs under control conditions and during phenylephrine or isoproterenol infusion were analyzed by a recirculatory model to estimate the relative dispersions of transit times across the systemic and pulmonary circulation. The transit time dispersion in the systemic circulation was used to calculate the whole body distribution clearance, and an interpretation is given in terms of a lumped organ model of blood-tissue exchange. As predicted by theory, this relative dispersion increased linearly with cardiac output, with a slope that was inversely related to solute diffusivity. The relative dispersion of the flow-limited indicator antipyrine exceeded that of ICG (as a measure of intravascular mixing) only slightly and was consistent with a diffusional equilibration time in the extravascular space of approximately 10 min, except during phenylephrine infusion, which led to an anomalously high relative dispersion. A change in cardiac output did not alter the heterogeneity of capillary transit times of ICG. The results support the view that the relative dispersions of transit times in the systemic and pulmonary circulation estimated from solute disposition data in vivo are useful measures of whole body distribution kinetics of indicators and endogenous substances. This is the first model that explains the effect of flow and capillary permeability on whole body distribution of solutes without assuming well-mixed compartments.

  7. Optimization of Advanced ACTPol Transition Edge Sensor Bolometer Operation Using R(T,I) Transition Measurements

    Science.gov (United States)

    Salatino, Maria

    2017-06-01

    In the current submm and mm cosmology experiments the focal planes are populated by kilopixel transition edge sensors (TESes). Varying incoming power load requires frequent rebiasing of the TESes through standard current-voltage (IV) acquisition. The time required to perform IVs on such large arrays and the resulting transient heating of the bath reduces the sky observation time. We explore a bias step method that significantly reduces the time required for the rebiasing process. This exploits the detectors' responses to the injection of a small square wave signal on top of the dc bias current and knowledge of the shape of the detector transition R(T,I). This method has been tested on two detector arrays of the Atacama Cosmology Telescope (ACT). In this paper, we focus on the first step of the method, the estimate of the TES %Rn.

  8. Effects of barium concentration on oropharyngeal swallow timing measures.

    Science.gov (United States)

    Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

    2014-02-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

  9. Transiting Exoplanet Monitoring Project (TEMP). II. Refined System Parameters and Transit Timing Analysis of HAT-P-33b

    Science.gov (United States)

    Wang, Yong-Hao; Wang, Songhu; Liu, Hui-Gen; Hinse, Tobias C.; Laughlin, Gregory; Wu, Dong-Hong; Zhang, Xiaojia; Zhou, Xu; Wu, Zhenyu; Zhou, Ji-Lin; Wittenmyer, R. A.; Eastman, Jason; Zhang, Hui; Hori, Yasunori; Narita, Norio; Chen, Yuanyuan; Ma, Jun; Peng, Xiyan; Zhang, Tian-Meng; Zou, Hu; Nie, Jun-Dan; Zhou, Zhi-Min

    2017-08-01

    We present 10 R-band photometric observations of eight different transits of the hot Jupiter HAT-P-33b, which has been targeted by our Transiting Exoplanet Monitoring Project. The data were obtained by two telescopes at the Xinglong Station of National Astronomical Observatories of China (NAOC) from 2013 December through 2016 January, and exhibit photometric scatter of 1.6{--}3.0 {mmag}. After jointly analyzing the previously published photometric data, radial-velocity (RV) measurements, and our new light curves, we revisit the system parameters and orbital ephemeris for the HAT-P-33b system. Our results are consistent with the published values except for the planet to star radius ratio ({R}{{P}}/{R}* ), the ingress/egress duration (τ) and the total duration (T 14), which together indicate a slightly shallower and shorter transit shape. Our results are based on more complete light curves, whereas the previously published work had only one complete transit light curve. No significant anomalies in Transit Timing Variations (TTVs) are found, and we place upper mass limits on potential perturbers, largely supplanting the loose constraints provided by the extant RV data. The TTV limits are stronger near mean-motion resonances, especially for the low-order commensurabilities. We can exclude the existence of a perturber with mass larger than 0.6, 0.3, 0.5, 0.5, and 0.3 {M}\\oplus near the 1:3, 1:2, 2:3, 3:2, and 2:1 resonances, respectively.

  10. The length and time scales of water's glass transitions

    Science.gov (United States)

    Limmer, David T.

    2014-06-01

    Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

  11. The length and time scales of water's glass transitions.

    Science.gov (United States)

    Limmer, David T

    2014-06-07

    Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

  12. Renewable Energy Policies in a Time of Transition

    International Nuclear Information System (INIS)

    Murdock, Hannah E.; Adib, Rana; Lins, Christine; Guerra, Flavia; Misra, Archita; Murdock, Hannah E.; Vickery, Louise; Collier, Ute; Le Feuvre, Pharoah; Bianco, Emanuele; Mueller, Simon; Philibert, Cedric; Schmidt, Oliver; Kvarnstroem, Oskar; Collier, Ute; Hungerford, Zoe; Frankl, Paolo; Bianco, Emanuele; Hawila, Diala; Ferroukhi, Rabia; Hawila, Diala; Renner, Michael; Nagpal, Divyam; Cox, Sadie; Esterly, Sean; Priesmann, Caspar; Taylor, Hadley; Breitschopf, Barbara; Van Rooijen, Sascha

    2018-01-01

    Spurred by innovation, increased competition, and policy support in a growing number of countries, renewable energy technologies have achieved massive technological advances and sharp cost reductions. Renewables have come to the forefront of the global energy transition, with nearly every country adopting a renewable energy target. Yet progress has been uneven in different countries and sectors. Technology and financial risks still hamper the expansion of renewables into new markets. As the power sector develops further, the increased adoption of variable renewables like solar and wind requires more flexible systems. Compared to power generation, the regulatory framework for end-use sectors lags behind. This report, prepared jointly by the International Renewable Energy Agency (IRENA), the International Energy Agency (IEA) and the Renewable Energy Policy Network for the 21. Century (REN21), identifies key barriers and highlights policy options to boost renewable energy deployment. After reviewing current policies and targets worldwide, it examines sector-specific policies for heating and cooling, transport and power, as well as measures for integrating variable renewables. An updated policy classification and terminology list can serve as a global reference for renewable energy policy instruments. Among the key findings: Renewable energy policies must focus on end-use sectors, not just power generation; The use of renewables for heating and cooling requires greater policy attention, including dedicated targets, technology mandates, financial incentives, generation-based incentives, and carbon or energy taxes; Policies in the transport sector require further development, including integrated policies to de-carbonise energy carriers and fuels, vehicles and infrastructure; Policies in the power sector must also evolve further to address new challenges. Measures are needed to support the integration of variable renewable energy, taking into account the specific

  13. Effects of Barium Concentration on Oropharyngeal Swallow Timing Measures

    OpenAIRE

    Stokely, Shauna L.; Molfenter, Sonja M.; Steele, Catriona M.

    2013-01-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between “thin” (40 % w/v concentration) and “ultrathin” (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; ...

  14. Recurrence and symmetry of time series: Application to transition detection

    International Nuclear Information System (INIS)

    Girault, Jean-Marc

    2015-01-01

    Highlights: •A new theoretical framework based on the symmetry concept is proposed. •Four types of symmetry present in any time series were analyzed. •New descriptors make possible the analysis of regime changes in logistic systems. •Chaos–chaos, chaos–periodic, symmetry-breaking, symmetry-increasing bifurcations can be detected. -- Abstract: The study of transitions in low dimensional, nonlinear dynamical systems is a complex problem for which there is not yet a simple, global numerical method able to detect chaos–chaos, chaos–periodic bifurcations and symmetry-breaking, symmetry-increasing bifurcations. We present here for the first time a general framework focusing on the symmetry concept of time series that at the same time reveals new kinds of recurrence. We propose several numerical tools based on the symmetry concept allowing both the qualification and quantification of different kinds of possible symmetry. By using several examples based on periodic symmetrical time series and on logistic and cubic maps, we show that it is possible with simple numerical tools to detect a large number of bifurcations of chaos–chaos, chaos–periodic, broken symmetry and increased symmetry types

  15. Accuracy of single photoelectron time spread measurement of fast photomultipliers

    International Nuclear Information System (INIS)

    Leskovar, B.

    1975-01-01

    The accuracy of time spread measurements of fast photomultipliers was investigated, using single photoelectrons. The effect of the finite light pulse width on the measurement accuracy was determined and discussed. Experimental data were obtained on a special measuring system for light pulse widths ranging from 200 psec to 10 nsec, using fast photomultipliers 8850 and C31024 with optimized operating conditions for minimum transit time spread. A modified exponential function expression and curve-fitting parameters are given, which fit closely the experimentally obtained data over a wide dynamic range of light pulse widths. (U.S.)

  16. The effects of hypercapnia on cortical capillary transit time heterogeneity (CTH) in anesthetized mice

    DEFF Research Database (Denmark)

    Gutiérrez-Jiménez, Eugenio; Angleys, Hugo; Rasmussen, Peter Mondrup

    2018-01-01

    Capillary flow patterns are highly heterogeneous in the resting brain. During hyperemia, capillary transit-time heterogeneity (CTH) decreases, in proportion to blood's mean transit time (MTT) in passive, compliant microvascular networks. Previously, we found that functional activation reduces...

  17. The Time Course of the Probability of Transition Into and Out of REM Sleep

    Science.gov (United States)

    Bassi, Alejandro; Vivaldi, Ennio A.; Ocampo-Garcés, Adrián

    2009-01-01

    Study Objectives: A model of rapid eye movement (REM) sleep expression is proposed that assumes underlying regulatory mechanisms operating as inhomogenous Poisson processes, the overt results of which are the transitions into and out of REM sleep. Design: Based on spontaneously occurring REM sleep episodes (“Episode”) and intervals without REM sleep (“Interval”), 3 variables are defined and evaluated over discrete 15-second epochs using a nonlinear logistic regression method: “Propensity” is the instantaneous rate of into-REM transition occurrence throughout an Interval, “Volatility” is the instantaneous rate of out-of-REM transition occurrence throughout an Episode, and “Opportunity” is the probability of being in non-REM (NREM) sleep at a given time throughout an Interval, a requisite for transition. Setting: 12:12 light:dark cycle, isolated boxes. Participants: Sixteen male Sprague-Dawley rats Interventions: None. Spontaneous sleep cycles. Measurements and Results: The highest levels of volatility and propensity occur, respectively, at the very beginning of Episodes and Intervals. The new condition stabilizes rapidly, and variables reach nadirs at minute 1.25 and 2.50, respectively. Afterward, volatility increases markedly, reaching values close to the initial level. Propensity increases moderately, the increment being stronger through NREM sleep bouts occurring at the end of long Intervals. Short-term homeostasis is evidenced by longer REM sleep episodes lowering propensity in the following Interval. Conclusions: The stabilization after transitions into Episodes or Intervals and the destabilization after remaining for some time in either condition may be described as resulting from continuous processes building up during Episodes and Intervals. These processes underlie the overt occurrence of transitions. Citation: Bassi A; Vivaldi EA; Ocampo-Garcées A. The time course of the probability of transition into and out of REM sleep. SLEEP 2009

  18. Effects of snowmelt on watershed transit time distributions

    Science.gov (United States)

    Fang, Z.; Carroll, R. W. H.; Harman, C. J.; Wilusz, D. C.; Schumer, R.

    2017-12-01

    Snowmelt is the principal control of the timing and magnitude of water flow through alpine watersheds, but the streamflow generated may be displaced groundwater. To quantify this effect, we use a rank StorAge Selection (rSAS) model to estimate time-dependent travel time distributions (TTDs) for the East River Catchment (ERC, 84 km2) - a headwater basin of the Colorado River, and newly designated as the Lawrence Berkeley National Laboratory's Watershed Function Science Focus Area (SFA). Through the SFA, observational networks related to precipitation and stream fluxes have been established with a focus on environmental tracers and stable isotopes. The United Stated Geological Survey Precipitation Runoff Modeling System (PRMS) was used to estimate spatially- and temporally-variable boundary fluxes of effective precipitation (snowmelt & rain), evapotranspiration, and subsurface storage. The DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm was used to calibrate the rSAS model to observed stream isotopic concentration data and quantify uncertainty. The sensitivity of the simulated TTDs to systematic changes in the boundary fluxes was explored. Different PRMS and rSAS model parameters setup were tested to explore how they affect the relationship between input precipitation, especially snowmelt, and the estimated TTDs. Wavelet Coherence Analysis (WCA) was applied to investigate the seasonality of TTD simulations. Our ultimate goal is insight into how the Colorado River headwater catchments store and route water, and how sensitive flow paths and transit times are to climatic changes.

  19. Effect of Laparoscopic-assisted Gastropexy on Gastrointestinal Transit Time in Dogs.

    Science.gov (United States)

    Balsa, I M; Culp, W T N; Drobatz, K J; Johnson, E G; Mayhew, P D; Marks, S L

    2017-11-01

    Prophylactic gastropexy has been promoted as a means of preventing gastric volvulus during gastric dilatation and volvulus (GDV) syndrome. Little is known about the impact of gastropexy on gastrointestinal transit time. Laparoscopic-assisted gastropexy (LAG) will not alter gastrointestinal transit times when comparing gastric (GET), small and large bowel (SLBTT), and whole gut transit times (TTT) before and after surgery. 10 healthy client-owned large-breed dogs. Prospective clinical trial. Before surgery, all dogs underwent physical examination and diagnostic evaluation to ensure normal health status. Dogs were fed a prescription diet for 6 weeks before determination of gastrointestinal transit with a wireless motility capsule. LAG was then performed, and dogs were fed the diet for 6 additional weeks. Measurement of transit times was repeated 6 weeks after surgery. Ten dogs of various breeds at-risk for GDV were enrolled. No complications were encountered associated with surgery or capsule administration. There were no significant differences in GET 429 [306-1,370] versus 541 [326-1,298] (P = 0.80), SLBTT 1,243 [841-3,070] versus 1,540 [756-2,623] (P = 0.72), or TTT 1,971 [1,205-3,469] versus 1,792 [1,234-3,343] minutes (median, range) (P = 0.65) before and after LAG. An effect of LAG on gastrointestinal transit time was not identified, and wireless motility capsule can be safely administered in dogs after LAG. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  20. A methodology for rearranging transit stops for enhancing transit users generalized travel time

    Directory of Open Access Journals (Sweden)

    Mohammad Nurul Hassan

    2017-02-01

    Full Text Available This study develops a methodology to consolidate transit stops. It develops a mathematical model and a program which takes stop consolidation decision(s according to users generalized travel time savings and desired accessibility. The model iterates until the users generalized travel time savings are maximized. The study tests this mathematical model in different hypothetical scenarios. Six factors (distance between stops, passenger activity, average cruising speed, maximum walking distance, service frequency, and percentage of decreased passengers with multiple levels were set to build the scenarios. Three responses (percentage of consolidated stops, percentages of travel time and operating time savings were observed. The findings showed that the distance between the stops the passenger activity, and the probable demand change (or the percentage of decreased passengers are the most influential factors. The frequency of service was found to be influential as well. The average cruising speed has very little influence on the response variables. Finally, the model is tested on two routes (route 900 and 930 of Al Ain City public bus service. It shows that 22 and 32 out of 98 and 126 stops can be consolidated in route 900 and 930 respectively. This can save considerable amounts of users travel and operating times. In monetary values, the savings are about $329,827 and $491,094 per year for routes 900 and 930, respectively.

  1. Daylight savings time transitions and the incidence rate of unipolar depressive episodes

    DEFF Research Database (Denmark)

    Hansen, Bertel T; Sønderskov, Kim M; Hageman, Ida

    2017-01-01

    Background: Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate...... of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes. Methods...

  2. Water Storage, Mixing and Transit Times During a Multiyear Drought.

    Science.gov (United States)

    Van der Velde, Y.; Visser, A.; Thaw, M.; Safeeq, M.

    2017-12-01

    From 2012 to 2016, a five year intensive drought occurred in the Californian Sierra Nevada. We use this drought period as an opportunity to investigate how catchment water storage, mixing and transit times changes from wet to dry conditions using long term datasets of river discharge, evapotranspiration, water quality, and multiple cosmogenic radioactive isotopes. Characteristic features of the test catchment (4.6 km2 , altitude 1660-2117 m) include a thick (>5m) unsaturated zone in deeply weathered granite mountain soils, snow melt and events of high intensity rainfall, dry summers and numerous wetland meadows along the stream. Our data and model analysis suggest that under drought conditions, river flow predominantly consist of deep groundwater tapped by deeply incised sections of the stream, while the wetlands hold on to their water just below the root system of its shallow rooting vegetation. In contrast, during wet periods, most runoff is generated on the flat riparian wetland meadows, while the regional groundwater system slowly refills itself as water makes its way through the thick unsaturated zones. Antecedent wet or dry years play an crucial role as antecedent wet years cause a substantial regional groundwater flow towards the riparian wetlands, filling up the riparian wetlands and yielding a much stronger discharge response of the wetlands to rainfall events than under antecedent dry years This interaction between the regional groundwater system and the local wetland systems weakens as the drought progresses and regional groundwater flow to the wetlands lessens. Although, due to the wet events in 2016-2017, the catchment fills up rapidly to pre-drought conditions, we show that water transit times and therefore likely the water quality will contain drought signs for several years to come. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS- XXXXXX

  3. Transit-Time Damping, Landau Damping, and Perturbed Orbits

    Science.gov (United States)

    Simon, A.; Short, R. W.

    1997-11-01

    Transit-time damping(G.J. Morales and Y.C. Lee, Phys. Rev. Lett. 33), 1534 (1974).*^,*(P.A. Robinson, Phys. Fluids B 3), 545 (1991).** has traditionally been obtained by calculating the net energy gain of transiting electrons, of velocity v, to order E^2* in the amplitude of a localized electric field. This necessarily requires inclusion of the perturbed orbits in the equation of motion. A similar method has been used by others(D.R. Nicholson, Introduction to Plasma Theory) (Wiley, 1983).*^,*(E.M. Lifshitz and L.P. Pitaevskifi, Physical Kinetics) (Pergamon, 1981).** to obtain a ``physical'' picture of Landau damping in a nonlocalized field. The use of perturbed orbits seems odd since the original derivation of Landau (and that of Dawson) never went beyond a linear picture of the dynamics. We introduce a novel method that takes advantage of the time-reversal invariance of the Vlasov equation and requires only the unperturbed orbits to obtain the result. Obviously, there is much reduction in complexity. Application to finite slab geometry yields a simple expression for the damping rate. Equivalence to much more complicated results^2* is demonstrated. This method allows us to calculate damping in more complicated geometries and more complex electric fields, such as occur in SRS in filaments. See accompanying talk.(R.W. Short and A. Simon, this conference.) This work was supported by the U.S. DOE Office of Inertial Confinement Fusion under Co-op Agreement No. DE-FC03-92SF19460.

  4. Measuring device for control rod driving time

    International Nuclear Information System (INIS)

    Tanaka, Kazuhiko; Hanabusa, Masatoshi.

    1993-01-01

    The present invention concerns a measuring device for control driving time having a function capable of measuring a selected control rod driving time and measuring an entire control rod driving time simultaneously. A calculation means and a store means for the selected rod control rod driving time, and a calculation means and a store means for the entire control rod driving time are disposed individually. Each of them measures the driving time and stores the data independent of each other based on a selected control rod insert ion signal and an entire control rod insertion signal. Even if insertion of selected and entire control rods overlaps, each of the control rod driving times can be measured reliably to provide an advantageous effect capable of more accurately conducting safety evaluation for the nuclear reactor based on the result of the measurement. (N.H.)

  5. Continuous quantum measurement and the quantum to classical transition

    International Nuclear Information System (INIS)

    Bhattacharya, Tanmoy; Habib, Salman; Jacobs, Kurt

    2003-01-01

    While ultimately they are described by quantum mechanics, macroscopic mechanical systems are nevertheless observed to follow the trajectories predicted by classical mechanics. Hence, in the regime defining macroscopic physics, the trajectories of the correct classical motion must emerge from quantum mechanics, a process referred to as the quantum to classical transition. Extending previous work [Bhattacharya, Habib, and Jacobs, Phys. Rev. Lett. 85, 4852 (2000)], here we elucidate this transition in some detail, showing that once the measurement processes that affect all macroscopic systems are taken into account, quantum mechanics indeed predicts the emergence of classical motion. We derive inequalities that describe the parameter regime in which classical motion is obtained, and provide numerical examples. We also demonstrate two further important properties of the classical limit: first, that multiple observers all agree on the motion of an object, and second, that classical statistical inference may be used to correctly track the classical motion

  6. Lifetime measurements and dipole transition rates for superdeformed states in {sup 190}Hg.

    Energy Technology Data Exchange (ETDEWEB)

    Amro, H.

    1999-03-24

    The Doppler-shift attenuation method was used to measure life-times of superdeformed (SD) states for both the yrast and the first excited superdeformed band of {sup 190}Hg. Intrinsic quadruple moments Q{sub 0} were extracted. For the first time, the dipole transition rates have been extracted for the inter-band transitions which connect the excited SD band to the yrast states in the second minimum. The results support the interpretation of the excited SD band as a rotational band built on an octupole vibration.

  7. Lifetime measurements and dipole transition rates for superdeformed states in 190Hg

    International Nuclear Information System (INIS)

    Amro, H.

    1999-01-01

    The Doppler-shift attenuation method was used to measure life-times of superdeformed (SD) states for both the yrast and the first excited superdeformed band of 190 Hg. Intrinsic quadruple moments Q 0 were extracted. For the first time, the dipole transition rates have been extracted for the inter-band transitions which connect the excited SD band to the yrast states in the second minimum. The results support the interpretation of the excited SD band as a rotational band built on an octupole vibration

  8. Lesions Responsible for Delayed Oral Transit Time in Post-stroke Dysphagia.

    Science.gov (United States)

    Moon, Hyun Im; Yoon, Seo Yeon; Yi, Tae Im; Jeong, Yoon Jeong; Cho, Tae Hwan

    2017-10-11

    Some stroke patients show oral phase dysphagia, characterized by a markedly prolonged oral transit time that hinders oral feeding. The aim of this study was to clarify the clinical characteristics and lesions responsible for delayed swallowing. We reviewed 90 patients with stroke. The oral processing time plus the postfaucial aggregation time required to swallow semisolid food was assessed. The patients were divided into two groups according to oral transit time, and we analyzed the differences in characteristics such as demographic factors, lesion factors, and cognitive function. Logistic regression analyses were performed to examine the predictors of delayed oral transit time. Lesion location and volume were measured on brain magnetic resonance images. We generated statistic maps of lesions related to delayed oral phase in swallowing using voxel-based lesion symptom mapping (VLSM). The group of patients who showed delayed oral transit time had significantly low cognitive function. Also, in a regression model, delayed oral phase was predicted with low K-MMSE (Korean version of the Mini Mental Status Exam). Using VLSM, we found the lesion location to be associated with delayed oral phase after adjusting for K-MMSE score. Although these results did not reach statistical significance, they showed the lesion pattern with predominant distribution in the left frontal lobe. Delayed oral phase in post-stroke patients was not negligible clinically. Patients' cognitive impairments affect the oral transit time. When adjusting it, we found a trend that the lesion responsible for delayed oral phase was located in the left frontal lobe, though the association did not reach significance. The delay might be related to praxis function.

  9. arXiv Measurement of the $\\pi^0$ electromagnetic transition form factor slope

    CERN Document Server

    Lazzeroni, C.; Romano, A.; Blazek, T.; Koval, M.; Ceccucci, A.; Danielsson, H.; Falaleev, V.; Gatignon, L.; Goy Lopez, S.; Hallgren, B.; Maier, A.; Peters, A.; Piccini, M.; Riedler, P.; Frabetti, P.L.; Gersabeck, E.; Kekelidze, V.; Madigozhin, D.; Misheva, M.; Molokanova, N.; Movchan, S.; Potrebenikov, Yu.; Shkarovskiy, S.; Zinchenko, A.; Rubin, P.; Baldini, W.; Cotta Ramusino, A.; Dalpiaz, P.; Fiorini, M.; Gianoli, A.; Norton, A.; Petrucci, F.; Savrié, M.; Wahl, H.; Bizzeti, A.; Bucci, F.; Iacopini, E.; Lenti, M.; Veltri, M.; Antonelli, A.; Moulson, M.; Raggi, M.; Spadaro, T.; Eppard, K.; Hita-Hochgesand, M.; Kleinknecht, K.; Renk, B.; Wanke, R.; Winhart, A.; Winston, R.; Bolotov, V.; Duk, V.; Gushchin, E.; Ambrosino, F.; Di Filippo, D.; Massarotti, P.; Napolitano, M.; Palladino, V.; Saracino, G.; Anzivino, G.; Imbergamo, E.; Piandani, R.; Sergi, A.; Cenci, P.; Pepe, M.; Costantini, F.; Doble, N.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Balev, S.; Collazuol, G.; DiLella, L.; Gallorini, S.; Goudzovski, E.; Lamanna, G.; Mannelli, I.; Ruggiero, G.; Cerri, C.; Fantechi, R.; Kholodenko, S.; Kurshetsov, V.; Obraztsov, V.; Semenov, V.; Yushchenko, O.; D'Agostini, G.; Leonardi, E.; Serra, M.; Valente, P.; Fucci, A.; Salamon, A.; Bloch-Devaux, B.; Peyaud, B.; Engelfried, J.; Coward, D.; Kozhuharov, V.; Litov, L.; Arcidiacono, R.; Bifani, S.; Biino, C.; Dellacasa, G.; Marchetto, F.; Numao, T.; Retière, F.

    2017-05-10

    The NA62 experiment collected a large sample of charged kaon decays in 2007 with a highly efficient trigger for decays into electrons. A measurement of the $\\pi^{0}$ electromagnetic transition form factor slope parameter from $1.11\\times10^{6}$ fully reconstructed $K^\\pm \\to \\pi^\\pm \\pi^0_D, \\; \\pi^0_D \\to e^+ e^- \\, \\gamma$ events is reported. The measured value $a = \\left(3.68 \\pm 0.57\\right)\\times 10^{-2}$ is in good agreement with theoretical expectations and previous measurements, and represents the most precise experimental determination of the slope in the time-like momentum transfer region.

  10. Quantum processes: probability fluxes, transition probabilities in unit time and vacuum vibrations

    International Nuclear Information System (INIS)

    Oleinik, V.P.; Arepjev, Ju D.

    1989-01-01

    Transition probabilities in unit time and probability fluxes are compared in studying the elementary quantum processes -the decay of a bound state under the action of time-varying and constant electric fields. It is shown that the difference between these quantities may be considerable, and so the use of transition probabilities W instead of probability fluxes Π, in calculating the particle fluxes, may lead to serious errors. The quantity W represents the rate of change with time of the population of the energy levels relating partly to the real states and partly to the virtual ones, and it cannot be directly measured in experiment. The vacuum background is shown to be continuously distorted when a perturbation acts on a system. Because of this the viewpoint of an observer on the physical properties of real particles continuously varies with time. This fact is not taken into consideration in the conventional theory of quantum transitions based on using the notion of probability amplitude. As a result, the probability amplitudes lose their physical meaning. All the physical information on quantum dynamics of a system is contained in the mean values of physical quantities. The existence of considerable differences between the quantities W and Π permits one in principle to make a choice of the correct theory of quantum transitions on the basis of experimental data. (author)

  11. Transit Timing Variation analysis with Kepler light curves of KOI 227 and Kepler 93b

    Science.gov (United States)

    Dulz, Shannon; Reed, Mike

    2017-01-01

    By searching for transit signals in approximately 150,000 stars, NASA’s Kepler Space telescope found thousands of exoplanets over its primary mission from 2009 to 2013 (Tenenbaum et al. 2014, ApJS, 211, 6). Yet, a detailed follow-up examination of Kepler light curves may contribute more evidence on system dynamics and planetary atmospheres of these objects. Kepler’s continuous observing of these systems over the mission duration produced light curves of sufficient duration to allow for the search for transit timing variations. Transit timing variations over the course of many orbits may indicate a precessing orbit or the existence of a non-transiting third body such as another exoplanet. Flux contributions of the planet just prior to secondary eclipse may provide a measurement of bond albedo from the day-side of the transiting planet. Any asymmetries of the transit shape may indicate thermal asymmetries which can measure upper atmosphere motion of the planet. These two factors can constrain atmospheric models of close orbiting exoplanets. We first establish our procedure with the well-documented TTV system, KOI 227 (Nesvorny et al. 2014, ApJ, 790, 31). Using the test case of KOI 227, we analyze Kepler-93b for TTVs and day-side flux contributions. Kepler-93b is likely a rocky planet with R = 1.50 ± 0.03 Earth Radii and M = 2.59 ± 2.0 Earth Masses (Marcy et al. 2014, ApJS, 210, 20). This research is funded by a NASA EPSCoR grant.

  12. A pair spectrometer for measuring multipolarities of energetic nuclear transitions

    CERN Document Server

    Gulyás, J.; Krasznahorkay, A.J.; Csatlós, M.; Csige, L.; Gácsi, Z.; Hunyadi, M.; Krasznahorkay, A.; Vitéz, A.; Tornyi, T.G.

    2016-02-01

    A multi-detector array has been designed and constructed for the simultaneous measurement of energy- and angular correlations of electron-positron pairs. Experimental results are obtained over a wide angular range for high-energy transitions in 16O, 12C and 8Be. A comparison with GEANT simulations demonstrates that angular correlations between 50 and 180 degrees of the electron-positron pairs in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency.

  13. Use of a large time-compensated scintillation detector in neutron time-of-flight measurements

    International Nuclear Information System (INIS)

    Goodman, C.D.

    1979-01-01

    A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time. 3 claims

  14. Transit time homogenization in ischemic stroke - A novel biomarker of penumbral microvascular failure?

    DEFF Research Database (Denmark)

    Engedal, Thorbjørn S; Hjort, Niels; Hougaard, Kristina D

    2017-01-01

    Cerebral ischemia causes widespread capillary no-flow in animal studies. The extent of microvascular impairment in human stroke, however, is unclear. We examined how acute intra-voxel transit time characteristics and subsequent recanalization affect tissue outcome on follow-up MRI in a historic...... cohort of 126 acute ischemic stroke patients. Based on perfusion-weighted MRI data, we characterized voxel-wise transit times in terms of their mean transit time (MTT), standard deviation (capillary transit time heterogeneity - CTH), and the CTH:MTT ratio (relative transit time heterogeneity), which...... tissue, prolonged mean transit time (>5 seconds) and very low cerebral blood flow (≤6 mL/100 mL/min) was associated with high risk of infarction, largely independent of recanalization status. In the remaining mismatch region, low relative transit time heterogeneity predicted subsequent infarction...

  15. Colonic transit time is related to bacterial metabolism and mucosal turnover in the human gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    Little is known about how colonic transit time relates to human colonic metabolism, and its importance for host health, although stool consistency, a proxy for colonic transit time, has recently been negatively associated with gut microbial richness. To address the relationships between colonic t...... imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.......Little is known about how colonic transit time relates to human colonic metabolism, and its importance for host health, although stool consistency, a proxy for colonic transit time, has recently been negatively associated with gut microbial richness. To address the relationships between colonic...... transit time and the gut microbial composition and metabolism, we assessed the colonic transit time of 98 subjects using radiopaque markers, and profiled their gut microbiota by16S rRNA gene sequencing and their urine metabolome by ultra performance liquid chromatography mass spectrometry. Based...

  16. A non-destructive method to measure the thermal properties of frozen soils during phase transition

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2015-04-01

    Full Text Available Frozen soils cover about 40% of the land surface on the earth and are responsible for the global energy balances affecting the climate. Measurement of the thermal properties of frozen soils during phase transition is important for analyzing the thermal transport process. Due to the involvement of phase transition, the thermal properties of frozen soils are rather complex. This paper introduces the uses of a multifunctional instrument that integrates time domain reflectometry (TDR sensor and thermal pulse technology (TPT to measure the thermal properties of soil during phase transition. With this method, the extent of phase transition (freezing/thawing was measured with the TDR module; and the corresponding thermal properties were measured with the TPT module. Therefore, the variation of thermal properties with the extent of freezing/thawing can be obtained. Wet soils were used to demonstrate the performance of this measurement method. The performance of individual modules was first validated with designed experiments. The new sensor was then used to monitor the properties of soils during freezing–thawing process, from which the freezing/thawing degree and thermal properties were simultaneously measured. The results are consistent with documented trends of thermal properties variations.

  17. Colonic transit time and pressure based on Bernoulli's principle.

    Science.gov (United States)

    Uno, Yoshiharu

    2018-01-01

    Variations in the caliber of human large intestinal tract causes changes in pressure and the velocity of its contents, depending on flow volume, gravity, and density, which are all variables of Bernoulli's principle. Therefore, it was hypothesized that constipation and diarrhea can occur due to changes in the colonic transit time (CTT), according to Bernoulli's principle. In addition, it was hypothesized that high amplitude peristaltic contractions (HAPC), which are considered to be involved in defecation in healthy subjects, occur because of cecum pressure based on Bernoulli's principle. A virtual healthy model (VHM), a virtual constipation model and a virtual diarrhea model were set up. For each model, the CTT was decided according to the length of each part of the colon, and then calculating the velocity due to the cecum inflow volume. In the VHM, the pressure change was calculated, then its consistency with HAPC was verified. The CTT changed according to the difference between the cecum inflow volume and the caliber of the intestinal tract, and was inversely proportional to the cecum inflow volume. Compared with VHM, the CTT was prolonged in the virtual constipation model, and shortened in the virtual diarrhea model. The calculated pressure of the VHM and the gradient of the interlocked graph were similar to that of HAPC. The CTT and HAPC can be explained by Bernoulli's principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics.

  18. Time measurements for thermalequilibrium in spodumene crystals

    International Nuclear Information System (INIS)

    Fujii, A.T.; Isotani, S.

    1982-01-01

    Experiments for measurement of time taken to reach thermal equilibrium in Spodumene crystals - 2mm to 5,4mm thick - in the temperature range 100 0 to 250 0 C are described. The measurements indicate a linear relationship between time and thickenes for heating as well as for cooling. Difference in thermal equilibrium time for heating and for cooling is about of 20 seconds. (author) [pt

  19. Is direct measurement of time possible?

    Science.gov (United States)

    Reynolds, Thomas

    2017-08-01

    Is direct measurement of time possible? The answer to this question may depend upon how one understands time. Is time an essential constituent of physical reality? Or is what scientists are talking about when they use the symbol ‘t’ or the word ‘time’ an human cultural construct, as the Chief of the USA NIST Divisions of Time and Frequency and of Quantum Physics has suggested. Few aspects of physics do not reference activity to time, but many discussions within either view of time seem to use one same, largely traditional, language of time. Briefly considering the question of measurement, including from a formal measure-theoretic point of view, clarifies the situation.

  20. An USB-based time measurement system

    International Nuclear Information System (INIS)

    Qin Xi; Liu Shubin; An Qi

    2010-01-01

    In this paper,we report the electronics of a timing measurement system of PTB(portable TDC board), which is a handy tool based on USB interface, customized for high precision time measurements without any crates. The time digitization is based on the High Performance TDC Chip (HPTDC). The real-time compensation for HPTDC outputs and the USB master logic are implemented in an ALTERA's Cyclone FPGA. The architecture design and logic design are described in detail. Test of the system showed a time resolution of 13.3 ps. (authors)

  1. Additive measures of travel time variability

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2011-01-01

    This paper derives a measure of travel time variability for travellers equipped with scheduling preferences defined in terms of time-varying utility rates, and who choose departure time optimally. The corresponding value of travel time variability is a constant that depends only on preference...... parameters. The measure is unique in being additive with respect to independent parts of a trip. It has the variance of travel time as a special case. Extension is provided to the case of travellers who use a scheduled service with fixed headway....

  2. Frequency Comb Driven Raman Transitions in the THz Range: High Precision Isotope Shift Measurements in Ca+

    DEFF Research Database (Denmark)

    Meyer, Steffen

    2017-01-01

    and frequency resolved optical gating (FROG) are used, and the two frequency comb systems used for the experiments are thoroughly characterized, a Coherent Mira Ti:sapph oscillator and a MenloSystems fiber based frequency comb system. The potential of frequency comb driven Raman transitions is shown...... transition frequencies typically are on the order of a few THz. High precision measurements on these ions have many intriguing applications, for example the test of time-variations of fundamental constants, ultracold chemistry on the quantum level, and quantum information and computing, to name just a few...

  3. H/L transition time estimation in JET using conformal predictors

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, S., E-mail: sergio.gonzalez@ciemat.es [Asociacion EURATOM/CIEMAT para Fusion, Madrid 28040 (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid 28040 (Spain); Murari, A. [Consorzio RFX, Associazione EURATOM/ENEA per la Fusione, Padova 4-25127 (Italy); Pereira, A. [Asociacion EURATOM/CIEMAT para Fusion, Madrid 28040 (Spain); Dormido-Canto, S.; Ramirez, J.M. [Departamento de Informatica y Automatica, UNED, Madrid 28040 (Spain)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer H/L transitions have been predicted using H/L and L/H models. Black-Right-Pointing-Pointer Models have been built using conformal predictors to hedge the prediction with confidence and credibility measures. Black-Right-Pointing-Pointer Models have been trained using linear and radial basis function kernels. Black-Right-Pointing-Pointer Conformal measures have proven their usefulness to validate data-driven models. - Abstract: Recent advances in data mining allow the automatic recognition of physical phenomena in the databases of fusion devices without human intervention. This is important to create large databases of physical events (thereby increasing the statistical relevance) in an unattended manner. Important examples are the L/H and H/L transitions. In this contribution, a novel technique is introduced to automatically locate H/L transitions in JET by using conformal predictors. The focus is on H/L transitions because typically there is not a clear signature in the time series of the most widely available signals to recognize the change of confinement. Conformal predictors hedge their prediction by means of two parameters: confidence and credibility. The technique has been based on binary supervised classifiers to separate the samples of the respective confinement modes. Results with several underlying classifiers are presented.

  4. Impedance measurements on a fast transition-edge sensor for optical and near-infrared range

    International Nuclear Information System (INIS)

    Taralli, E; Portesi, C; Lolli, L; Monticone, E; Rajteri, M; Novikov, I; Beyer, J

    2010-01-01

    Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 μm x 20 μm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C, thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.

  5. Gastrointestinal mean transit times in young and middle-aged healthy subjects

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2001-01-01

    To investigate the effects of age and gender on gastric, small intestinal and colonic mean transit times, a study was conducted in 32 healthy volunteers: eight young women (22-30 years), eight young men (20-28 years), eight middle-aged women (43-51 years) and eight middle-aged men (38-53 years......, small intestinal and colonic mean transit times were calculated. The gastric, small intestinal and colonic mean transit times were significantly longer in women. Ageing was shown to accelerate the gastric and small intestinal transit significantly. In the group of men the colonic mean transit time...... was unaffected by age, but middle-aged women had a significantly slower colonic transit than young women. We therefore conclude that both age and gender have to be considered when reference values for gastric, small intestinal and colonic mean transit times have to be established....

  6. Nanosecond time measurements of single pulse

    International Nuclear Information System (INIS)

    Xing Jingyuan; Cheng Shiyuan

    1986-01-01

    This report mainly describes the principle specification of circuit design and time-interval calibrations of model SHS 500 time-to-digital converter. Its range is 12 to 500 ns, with six ranges: 50, 100, 200, 300, 400 and 500 ns. The precision of measured time-interval is 0.3% of full scale and time resolution is 0.1% of full scale

  7. Alteration of gastrointestinal transit time in the rat after bile duct cannulation surgery

    International Nuclear Information System (INIS)

    Ayres, P.H.; Medinsky, M.A.; Muggenburg, B.A.; Bond, J.A.

    1985-01-01

    Alteration of gastrointestinal (GI) transit time could affect the bioavailability of a toxicant if the toxicant is absorbed in the GI tract. The effect of surgery on GI transit time was investigated using radiographic imaging of barium during passage through the GI tract of the rat. Bile duct cannulation surgery delayed transit of barium to over 18 h, whereas in the normal animal, transit required approximately 6 h. GI transit time was only moderately affected by laparotomy after an 18-h postsurgery recovery period. These results suggest that the gastrointestinal absorption of orally administered toxicants could be affected by bile duct cannulation. 3 references, 1 figure, 1 table

  8. The climate of HD 189733b from fourteen transits and eclipses measured by Spitzer

    Energy Technology Data Exchange (ETDEWEB)

    Agol, E.; /Washington U., Seattle, Astron. Dept. /Santa Barbara, KITP /UC, Santa Barbara; Cowan, Nicolas B.; /Washington U., Seattle, Astron. Dept.; Knutson, Heather A.; /UC, Berkeley, Astron. Dept.; Deming, Drake; /NASA, Goddard; Steffen, Jason H.; /Fermilab; Henry, Gregory W.; /Tennessee State U.; Charbonneau, David; /Harvard-Smithsonian Ctr. Astrophys.

    2010-07-01

    We present observations of six transits and six eclipses of the transiting planet system HD 189733 taken with the Spitzer Space Telescope IRAC camera at 8 microns, as well as a re-analysis of previously published data. We use several novel techniques in our data analysis, the most important of which is a new correction for the detector 'ramp' variation with a double-exponential function which performs better and is a better physical model for this detector variation. Our main scientific findings are: (1) an upper limit on the variability of the day-side planet flux of 2.7% (68% confidence); (2) the most precise set of transit times measured for a transiting planet, with an average accuracy of 3 seconds; (3) a lack of transit-timing variations, excluding the presence of second planets in this system above 20% of the mass of Mars in low-order mean-motion resonance at 95% confidence; (4) a confirmation of the planet's phase variation, finding the night side is 64% as bright as the day side, as well as an upper limit on the night-side variability of 17% (68% confidence); (5) a better correction for stellar variability at 8 micron causing the phase function to peak 3.5 hours before secondary eclipse, confirming that the advection and radiation timescales are comparable at the 8 micron photosphere; (6) variation in the depth of transit, which possibly implies variations in the surface brightness of the portion of the star occulted by the planet, posing a fundamental limit on non-simultaneous multi-wavelength transit absorption measurements of planet atmospheres; (7) a measurement of the infrared limb-darkening of the star, which is in good agreement with stellar atmosphere models; (8) an offset in the times of secondary eclipse of 69 seconds, which is mostly accounted for by a 31 second light travel time delay and 33 second delay due to the shift of ingress and egress by the planet hot spot; this confirms that the phase variation is due to an offset hot

  9. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Weitang; Zhang, Zhiyong; Liu, Jinbo; Li, Zhen; Song, Junmin; Wu, Changcai [Department of Colorectal Surgery, The First Affiliated Hospital and Institute of Clinical Medicine, Zhengzhou University, 450052 Zhengzhou (China); Wang, Guixian, E-mail: guixianwang@hotmail.com [Department of Colorectal Surgery, The First Affiliated Hospital and Institute of Clinical Medicine, Zhengzhou University, 450052 Zhengzhou (China)

    2012-09-15

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation.

  10. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    International Nuclear Information System (INIS)

    Yuan, Weitang; Zhang, Zhiyong; Liu, Jinbo; Li, Zhen; Song, Junmin; Wu, Changcai; Wang, Guixian

    2012-01-01

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation

  11. Double threshold discriminator for timing measurements

    International Nuclear Information System (INIS)

    Frolov, A.R.; Oslopova, T.V.; Pestov, Yu.N.

    1995-01-01

    The new type of a discriminator is based on the idea of simultaneous time measurements at two different thresholds for each pulse. Instead of using two independent electronic TDC channels this discriminator produces an output pulse with the timing taking into account the information from two time measurements ''on-line''. The operation principle, analytical calculations and experimental results are presented. The time walk of the discriminator at the level of 10 ps in the range of the input pulse height of 0.2-1.5 V has been obtained. ((orig.))

  12. Markov transition probability-based network from time series for characterizing experimental two-phase flow

    International Nuclear Information System (INIS)

    Gao Zhong-Ke; Hu Li-Dan; Jin Ning-De

    2013-01-01

    We generate a directed weighted complex network by a method based on Markov transition probability to represent an experimental two-phase flow. We first systematically carry out gas—liquid two-phase flow experiments for measuring the time series of flow signals. Then we construct directed weighted complex networks from various time series in terms of a network generation method based on Markov transition probability. We find that the generated network inherits the main features of the time series in the network structure. In particular, the networks from time series with different dynamics exhibit distinct topological properties. Finally, we construct two-phase flow directed weighted networks from experimental signals and associate the dynamic behavior of gas-liquid two-phase flow with the topological statistics of the generated networks. The results suggest that the topological statistics of two-phase flow networks allow quantitative characterization of the dynamic flow behavior in the transitions among different gas—liquid flow patterns. (general)

  13. Transition to motherhood and the self: measurement, stability, and change.

    Science.gov (United States)

    Ruble, D N; Brooks-Gunn, J; Fleming, A S; Fitzmaurice, G; Stangor, C; Deutsch, F

    1990-03-01

    Different ways of conceptualizing and measuring change in attitudes during transition to motherhood are examined. A series of analyses was performed on data from a cross-sectional sample (N = 667) and a smaller longitudinal sample (n = 48) to demonstrate sound psychometric properties for 2 new scales and to show construct comparability across different phases of childbearing. For Childbearing Attitudes Questionnaire, results demonstrated equality of covariance for 16 scales and comparability of structure and meaning of 4 higher order factors--identification with motherhood, social orientation, self-confidence, and negative aspects of giving birth. For Mothering Self-Definition Questionnaire, results demonstrated equality of covariance of 5 scales and comparability of structure and meaning of a single higher order factor, interpreted as reflecting positive feelings about one's mothering characteristics. Analyses of correlations and mean differences identified areas of change and stability.

  14. Sensitive Measurement of the Kosterlitz-Thouless Transition

    Science.gov (United States)

    Ben-Ezra, Shalva; Glaberson, William I.

    2006-09-01

    We have developed a new technique for probing the Kosterlitz - Thouless transition in thin helium films. The technique is based on operation of a single quartz crystal microbalance at two different harmonic frequencies simultaneously. The technique is insensitive to surface effects, and provides the means for monitoring the heating of the film. By suppressing heating and surface effects we were able to systematically compare the results with the existing theories of ANHS, Bowley, Armour and Benedict, and Armour and Bowley. Substantial agreement with the last model of Armour and Bowley was observed. To the best our knowledge this is the first time that the experimental data in the frequency range 10-30MHz is compared to theoretical models.

  15. Real time refractive index measurement by ESPI

    International Nuclear Information System (INIS)

    Torroba, R.; Joenathan, C.

    1991-01-01

    In this paper a method to measure refractive index variations in real time is reported. A technique to introduce reference fringes in real time is discussed. Both the theoretical and experimental results are presented and an example with phase shifting is given. (author). 8 refs, 5 figs

  16. Transit Timing Observations from Kepler: III. Confirmation of 4 Multiple Planet Systems by a Fourier-Domain Study of Anti-correlated Transit Timing Variations

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Fabrycky, Daniel C.; /Lick Observ.; Ford, Eric B.; /Florida U.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Welsh, William F.; /Caltech; Borucki, William J.; /NASA, Ames /UC, Santa Barbara

    2012-01-01

    We present a method to confirm the planetary nature of objects in systems with multiple transiting exoplanet candidates. This method involves a Fourier-domain analysis of the deviations in the transit times from a constant period that result from dynamical interactions within the system. The combination of observed anticorrelations in the transit times and mass constraints from dynamical stability allow us to claim the discovery of four planetary systems, Kepler-25, Kepler-26, Kepler-27 and Kepler-28, containing eight planets and one additional planet candidate.

  17. Time-resolved measurements of luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Collier, Bradley B. [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); McShane, Michael J., E-mail: mcshane@tamu.edu [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); Materials Science and Engineering Program, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States)

    2013-12-15

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described.

  18. Time-resolved measurements of luminescence

    International Nuclear Information System (INIS)

    Collier, Bradley B.; McShane, Michael J.

    2013-01-01

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described

  19. Measuring multiscaling in financial time-series

    International Nuclear Information System (INIS)

    Buonocore, R.J.; Aste, T.; Di Matteo, T.

    2016-01-01

    We discuss the origin of multiscaling in financial time-series and investigate how to best quantify it. Our methodology consists in separating the different sources of measured multifractality by analyzing the multi/uni-scaling behavior of synthetic time-series with known properties. We use the results from the synthetic time-series to interpret the measure of multifractality of real log-returns time-series. The main finding is that the aggregation horizon of the returns can introduce a strong bias effect on the measure of multifractality. This effect can become especially important when returns distributions have power law tails with exponents in the range (2, 5). We discuss the right aggregation horizon to mitigate this bias.

  20. Decreasing Transition Times in Elementary School Classrooms: Using Computer-Assisted Instruction to Automate Intervention Components

    Science.gov (United States)

    Hine, Jeffrey F.; Ardoin, Scott P.; Foster, Tori E.

    2015-01-01

    Research suggests that students spend a substantial amount of time transitioning between classroom activities, which may reduce time spent academically engaged. This study used an ABAB design to evaluate the effects of a computer-assisted intervention that automated intervention components previously shown to decrease transition times. We examined…

  1. Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System.

    Science.gov (United States)

    Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent; Gronbaek, Henning; Krogh, Klaus

    2015-07-30

    The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the performance of 3D-Transit in patients with carcinoid diarrhea and to compare the patients' regional gastrointestinal transit times (GITT) and colonic motility patterns with those of healthy subjects. Fifteen healthy volunteers and seven patients with neuroendocrine tumor and at least 3 bowel movements per day were inves-tigated with 3D-Transit and standard radiopaque markers. Total GITT assessed with 3D-Transit and radiopaque markers were well correlated (Spearman's rho = 0.64, P = 0.002). Median total GITT was 12.5 (range: 8.5-47.2) hours in patients versus 25.1 (range: 13.1-142.3) hours in healthy (P = 0.007). There was no difference in gastric emptying (P = 0.778). Median small intestinal transit time was 3.8 (range: 1.4-5.5) hours in patients versus 4.4 (range: 1.8-7.2) hours in healthy subjects (P = 0.044). Median colorectal transit time was 5.2 (range: 2.9-40.1) hours in patients versus 18.1 (range: 5.0-134.0) hours in healthy subjects (P = 0.012). Median frequency of pansegmental co-lonic movements was 0.45 (range: 0.03-1.02) per hour in patients and 0.07 (range: 0-0.61) per hour in healthy subjects (P = 0.045). Three-dimensional Transit allows assessment of regional GITT in patients with diarrhea. Patients with carcinoid diarrhea have faster than normal gastrointestinal transit due to faster small intestinal and colorectal transit times. The latter is caused by an increased frequency of pansegmental colonic movements.

  2. Transition in adolescents across time, disease and gender

    DEFF Research Database (Denmark)

    Svanholm, Jette Rolf; Ludvigsen, Mette Spliid; Aagaard, Hanne

    University, Denmark Jeanette.Svanholm@skejby.rm.dk, Mette.Ludvigsen@skejby.rm.dk, Hanne.Aagaard@skejby.rm.dk Background: Adolescents do not get involved in the preparation and planning of their health care transition, which leaves them with negative experiences and feelings of not having their health care......’ with congenial heart diseases, chronic kidney diseases and cystic fibrosis perspective. Objective: To study experiences of transition in adolescents with severe chronic diseases in the context of child-centred health care to adult-centred health care Research questions: • What are the adolescents’ experiences...... study, longitudinal design • systematic literature search • ethnographic fieldwork (Hammersley, Atkinson 2007) o participant observations of consultations between adolescents and health care staff o individual semi-structured interviews with the adolescents (Kvale, Brinkmann 2009). Participants...

  3. Comparison of active-set method deconvolution and matched-filtering for derivation of an ultrasound transit time spectrum

    International Nuclear Information System (INIS)

    Wille, M-L; Langton, C M; Zapf, M; Ruiter, N V; Gemmeke, H

    2015-01-01

    The quality of ultrasound computed tomography imaging is primarily determined by the accuracy of ultrasound transit time measurement. A major problem in analysis is the overlap of signals making it difficult to detect the correct transit time. The current standard is to apply a matched-filtering approach to the input and output signals. This study compares the matched-filtering technique with active set deconvolution to derive a transit time spectrum from a coded excitation chirp signal and the measured output signal. The ultrasound wave travels in a direct and a reflected path to the receiver, resulting in an overlap in the recorded output signal. The matched-filtering and deconvolution techniques were applied to determine the transit times associated with the two signal paths. Both techniques were able to detect the two different transit times; while matched-filtering has a better accuracy (0.13 μs versus 0.18 μs standard deviations), deconvolution has a 3.5 times improved side-lobe to main-lobe ratio. A higher side-lobe suppression is important to further improve image fidelity. These results suggest that a future combination of both techniques would provide improved signal detection and hence improved image fidelity. (note)

  4. NO TIMING VARIATIONS OBSERVED IN THIRD TRANSIT OF SNOW-LINE EXOPLANET KEPLER-421b

    International Nuclear Information System (INIS)

    Dalba, Paul A.; Muirhead, Philip S.

    2016-01-01

    We observed Kepler-421 during the anticipated third transit of the snow-line exoplanet Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Previously, the Kepler spacecraft only observed two transits of Kepler-421b, leaving the planet’s transit ephemeris unconstrained. Our visible light, time-series observations from the 4.3 m Discovery Channel Telescope were designed to capture pre-transit baseline and the partial transit of Kepler-421b, barring significant TTVs. We use the light curves to assess the probabilities of various transit models using both the posterior odds ratio and the Bayesian Information Criterion, and find that a transit model with no TTVs is favored to 3.6 σ confidence. These observations suggest that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the Kepler-421b ephemeris constrained, we calculate future transit times and discuss the opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy. Our investigation emphasizes the difficulties associated with observing long-period exoplanet transits and the consequences that arise from failing to refine transit ephemerides.

  5. Effect of Epidural Block under General Anesthesia on Pulse Transit Time

    International Nuclear Information System (INIS)

    Choi, Byeong Cheol; Kim, Seong Min; Jung, Dong Keun; Kim, Gi Ryon; Lee, He Jeong; Jeon, Gye Rock

    2005-01-01

    Epidural block under general anesthesia has been widely used to control postoperative pain. In this anesthetic state many hemodynamic parameters are changed. Moreover pulse transit time is influenced by this memodynamic change. PPT change in the finger and the toe due to relaxation of arterial wall muscle after general anesthesia and epidural block under general anesthesia. This study, in the both general anesthesia and epidural block under general anesthesia, ΔPTT of the toe and of the finger are measured. In addition, ΔPTT(toe-finger) of the epidural block under general anesthesia and of the general anesthesia were compared

  6. Uncertainties for pressure-time efficiency measurements

    OpenAIRE

    Ramdal, Jørgen; Jonsson, Pontus; Dahlhaug, Ole Gunnar; Nielsen, Torbjørn; Cervantes, Michel

    2010-01-01

     In connection with the pressure-time project at the Norwegian University of Science and Technology and Luleå University of Technology, a number of tests with the pressure-time method have been performed at the Waterpower Laboratory in Trondheim, Norway. The aim is to lower the uncertainty and improve usability of the method. Also a field test at the Anundsjoe power plant in Sweden has been performed. The pressure-time measurement is affected by random uncertainty. To minimize the effect of t...

  7. Potentiometric Measurement of Transition Ranges and Titration Errors for Acid/Base Indicators

    Science.gov (United States)

    Flowers, Paul A.

    1997-07-01

    Sophomore analytical chemistry courses typically devote a substantial amount of lecture time to acid/base equilibrium theory, and usually include at least one laboratory project employing potentiometric titrations. In an effort to provide students a laboratory experience that more directly supports their classroom discussions on this important topic, an experiment involving potentiometric measurement of transition ranges and titration errors for common acid/base indicators has been developed. The pH and visually-assessed color of a millimolar strong acid/base system are monitored as a function of added titrant volume, and the resultant data plotted to permit determination of the indicator's transition range and associated titration error. Student response is typically quite positive, and the measured quantities correlate reasonably well to literature values.

  8. Timely resolved measurements on CdSe nanoparticles

    International Nuclear Information System (INIS)

    Holt, B.E. von

    2006-01-01

    By means of infrared spectroscopy the influence of the organic cover on structure and dynamics of CdSe nanoparticles was studied. First a procedure was developed, which allows to get from the static infrared spectrum informations on the quality of the organic cover and the binding behaviour of the ligands. On qualitatively high-grade and well characterized samples thereafter the dynamics of the lowest-energy electron level 1S e was time-resolvedly meausred in thew visible range. As reference served CdSe TOPO, which was supplemented by samples with the ligands octanthiole, octanic acid, octylamine, naphthoquinone, benzoquinone, and pyridine. The studied nanoparticles had a diameter of 4.86 nm. By means of the excitation-scanning or pump=probe procedure first measurements in the picosecond range were performed. The excitation wavelengths were thereby spectrally confined and so chosen that selectively the transitions 1S 3/2 -1S-e and 1P 3/2 -1P e but not the intermediately lyingt transition 2S 3/2 -1S e were excited. The excitation energies were kept so low that the excitation of several excitons in one crystal could be avoided. The scanning wavelength in the infrared corresponded to the energy difference between the electron levels 1S e and 1P e . The transients in the picosecond range are marked by a steep increasement of the signal, on which a multi-exponential decay follows. The increasement, which reproduces the popiulation of the excited state, isa inependent on the choice of the ligands. The influence of the organic cover is first visible in the different decay times of the excited electron levels. the decay of the measurement signal of CdSe TOPO can be approximatively described by three time constants: a decay constant in the early picosecond region, a time constant around hundert picoseconds, and a time constant of some nanoseconds. At increasing scanning wavelength the decay constants become longer. By directed excitation of the 1S 3/2 -1S e and the 1P 3

  9. The time-varying shortest path problem with fuzzy transit costs and speedup

    Directory of Open Access Journals (Sweden)

    Rezapour Hassan

    2016-08-01

    Full Text Available In this paper, we focus on the time-varying shortest path problem, where the transit costs are fuzzy numbers. Moreover, we consider this problem in which the transit time can be shortened at a fuzzy speedup cost. Speedup may also be a better decision to find the shortest path from a source vertex to a specified vertex.

  10. Nonparametric estimation in an "illness-death" model when all transition times are interval censored

    DEFF Research Database (Denmark)

    Frydman, Halina; Gerds, Thomas; Grøn, Randi

    2013-01-01

    We develop nonparametric maximum likelihood estimation for the parameters of an irreversible Markov chain on states {0,1,2} from the observations with interval censored times of 0 → 1, 0 → 2 and 1 → 2 transitions. The distinguishing aspect of the data is that, in addition to all transition times ...

  11. Integral definition of transition time in the Landau-Zener model

    International Nuclear Information System (INIS)

    Yan Yue; Wu Biao

    2010-01-01

    We give a general definition for the transition time in the Landau-Zener model. This definition allows us to compute numerically the Landau-Zener transition time at any sweeping rate without ambiguity in both diabatic and adiabatic bases. With this new definition, analytical results are obtained in both the adiabatic limit and the sudden limit.

  12. Patterns of digital volume pulse waveform and pulse transit time in ...

    African Journals Online (AJOL)

    In this study the digital volume pulse wave and the pulse transit time of the thumb and big toe were analyzed in young and older subjects some of whom were hypertensive. We aimed to study the components and patterns of the pulse waveform and the pulse transit time and how they might change. Material and Methods: ...

  13. Quantum coherence in the time-resolved Auger measurement

    Energy Technology Data Exchange (ETDEWEB)

    Smirnova, Olga; Yakovlev, Vladislav S; Scrinzi, Armin

    2003-12-19

    We present a quantum mechanical model of the attosecond-XUV (extreme ultraviolet) pump and laser probe measurement of an Auger decay [Drescher et al., Nature (London) 419, 803 (2002)10.1038/nature01143] and investigate effects of quantum coherence. The time-dependent Schroedinger equation is solved by numerical integration and in analytic form. We explain the transition from a quasiclassical energy shift of the spectrum to the formation of sidebands and the enhancement of high- and low-energy tails of the Auger spectrum due to quantum coherence between photoionization and Auger decay.

  14. Boltzmann babies in the proper time measure

    Energy Technology Data Exchange (ETDEWEB)

    Bousso, Raphael; Bousso, Raphael; Freivogel, Ben; Yang, I-Sheng

    2007-12-20

    After commenting briefly on the role of the typicality assumption in science, we advocate a phenomenological approach to the cosmological measure problem. Like any other theory, a measure should be simple, general, well defined, and consistent with observation. This allows us to proceed by elimination. As an example, we consider the proper time cutoff on a geodesic congruence. It predicts that typical observers are quantum fluctuations in the early universe, or Boltzmann babies. We sharpen this well-known youngness problem by taking into account the expansion and open spatial geometry of pocket universes. Moreover, we relate the youngness problem directly to the probability distribution for observables, such as the temperature of the cosmic background radiation. We consider a number of modifications of the proper time measure, but find none that would make it compatible with observation.

  15. Spin transitions in time-dependent magnetic fields

    International Nuclear Information System (INIS)

    Garisto, F.; Sanctuary, B.C.

    1981-01-01

    Nonadiabatic transitions in state-selection experiments on beams of metastable hydrogen atoms (2S/sub 1/2/) display oscillations in the population of the F=1, m=-1 state [R. D. Hight and R. T. Robiscoe, Phys. Rev. A 17, 561 (1978)]. In this paper, theoretical calculations using exact and model solenoid fields averaged over a velocity distribution show that the population oscillations arise from the presence of at least two nonadiabatic regions in the solenoid. No oscillations occur theoretically if only a single nonadiabatic region exists, unless the unlikely assumption of a coherent hydrogen-atom beam is invoked

  16. Absolute transition probabilities of 5s-5p transitions of Kr I from interferometric measurements in LTE-plasmas

    International Nuclear Information System (INIS)

    Kaschek, K.; Ernst, G.K.; Boetticher, W.

    1984-01-01

    Absolute transition probabilities of nine 5s-5p transitions of Kr I have been evaluated by using the hook method. The plasma was produced in a shock tube. The population density of the 5s-levels was calculated, under the assumption of LTE, from the electron density and the ground state number measured by means of a dual wavelength interferometer. An evaluation is given which proves the validity of the LTE assumption. (orig.)

  17. An Evaluation of the Technical Adequacy of a Revised Measure of Quality Indicators of Transition

    Science.gov (United States)

    Morningstar, Mary E.; Lee, Hyunjoo; Lattin, Dana L.; Murray, Angela K.

    2016-01-01

    This study confirmed the reliability and validity of the Quality Indicators of Exemplary Transition Programs Needs Assessment-2 (QI-2). Quality transition program indicators were identified through a systematic synthesis of transition research, policies, and program evaluation measures. To verify reliability and validity of the QI-2, we…

  18. Time-resolved absorption measurements on OMEGA

    International Nuclear Information System (INIS)

    Jaanimagi, P.A.; DaSilva, L.; Delettrez, J.; Gregory, G.G.; Richardson, M.C.

    1986-01-01

    Time-resolved measurements of the incident laser light that is scattered and/or refracted from targets irradiated by the 24 uv-beam OMEGA laser at LLE, have provided some interesting features related to time-resolved absorption. The decrease in laser absorption characteristic of irradiating a target that implodes during the laser pulse has been observed. The increase in absorption expected as the critical density surface moves from a low to a high Z material in the target has also been noted. The detailed interpretation of these results is made through comparisons with simulation using the code LILAC, as well as with streak data from time-resolved x-ray imaging and spectroscopy. In addition, time and space-resolved imaging of the scattered light yields information on laser irradiation uniformity conditions on the target. The report consists of viewgraphs

  19. Comparing Transition-Edge Sensor Response Times in a Modified Contact Scheme with Different Support Beams

    Science.gov (United States)

    Beyer, A. D.; Kenyon, M. E.; Bumble, B.; Runyan, M. C.; Echternach, P. E.; Holmes, W. A.; Bock, J. J.; Bradford, C. M.

    2013-01-01

    We present measurements of the thermal conductance, G, and effective time constants, tau, of three transition-edge sensors (TESs) populated in arrays operated from 80-87mK with T(sub C) approximately 120mK. Our TES arrays include several variations of thermal architecture enabling determination of the architecture that demonstrates the minimum noise equivalent power (NEP), the lowest tau and the trade-offs among designs. The three TESs we report here have identical Mo/Cu bilayer thermistors and wiring structures, while the thermal architectures are: 1) a TES with straight support beams of 1mm length, 2) a TES with meander support beams of total length 2mm and with 2 phononfilter blocks per beam, and 3) a TES with meander support beams of total length 2mm and with 6 phonon-filter blocks per beam. Our wiring scheme aims to lower the thermistor normal state resistance R(sub N) and increase the sharpness of the transition alpha=dlogR/dlogT at the transition temperature T(sub C). We find an upper limit of given by (25+/-10), and G values of 200fW/K for 1), 15fW/K for 2), and 10fW/K for 3). The value of alpha can be improved by slightly increasing the length of our thermistors.

  20. VIDEO CAPSULE ENDOSCOPY: A TOOL FOR THE ASSESSMENT OF SMALL BOWEL TRANSIT TIME

    Directory of Open Access Journals (Sweden)

    Reza A Hejazi

    2016-02-01

    Full Text Available Purpose: Video capsule endoscopy (VCE is a procedure that uses a wireless camera to take pictures of the gastrointestinal tract. A wireless motility capsule (WMC of a similar size has been developed, which measures pH, pressure, and temperature, and can be used to assess regional and total gastrointestinal transit times. VCE could also potentially be used as a tool for measuring small bowel transit time (SBTT.Methods: This study was designed to obtain SBTT from VCE and compare it with historical data generated by WMC. Gastric transit time (GTT was also measured. Patients were included if the indication for VCE was either iron deficiency anemia (IDA or overt obscure GI bleed (OOGIB and they did not have any known motility disorder. Results from VCE were also compared in diabetic versus non-diabetic patients. Results: There were a total of 147 VCE studies performed, including 42 for OOGIB and 105 for IDA. Median GTT and SBTT were 0.3 and 3.6 hours, respectively. The overall median GTT and SBTT were 0.3 and 3.6 hours, respectively, in the IDA group compared with 0.3 and 3.4 hours in the OOGIB group. When compared with WMC, the GTT and SBTT were significantly faster in both groups (GTT: 3.6 hours and SBTT: 4.6 hours. The median GTT and SBTT were not significantly different in diabetics versus non-diabetics: (GTT: 17.5 vs. 18.0 minutes (P=0.86 and SBTT: 3.9 hours (237 minutes vs. 3.8 hours (230 minutes, respectively (P=0.90.Conclusion: SBTT as measured using VCE is not significantly different in OOGIB compared with IDA. Both GTT and SBTT are significantly faster as assessed by VCE, which is initiated in the fasting state, compared with WMC measurement, which is initiated after a standard meal. In summary, VCE could potentially be used for measuring SBTT in the fasting state.

  1. Video Capsule Endoscopy: A Tool for the Assessment of Small Bowel Transit Time.

    Science.gov (United States)

    Hejazi, Reza A; Bashashati, Mohammad; Saadi, Mohammed; Mulla, Zuber D; Sarosiek, Irene; McCallum, Richard W; Zuckerman, Marc J

    2016-01-01

    Video capsule endoscopy (VCE) is a procedure that uses a wireless camera to take pictures of the gastrointestinal (GI) tract. A wireless motility capsule (WMC) of a similar size has been developed, which measures pH, pressure, and temperature and can be used to assess regional and total GI transit times. VCE could also potentially be used as a tool for measuring small bowel transit time (SBTT). This study was designed to obtain SBTT from VCE and compare it with historical data generated by WMC. Gastric transit time (GTT) was also measured. Patients were included if the indication for VCE was either iron deficiency anemia (IDA) or overt obscure GI bleed (OOGIB), and they did not have any known motility disorder. Results from VCE were also compared in diabetic vs. non-diabetic patients. There were a total of 147 VCE studies performed, including 42 for OOGIB and 105 for IDA. Median GTT and SBTT were 0.3 and 3.6 h, respectively. The overall median GTT and SBTT were 0.3 and 3.6 h, respectively, in the IDA group compared with 0.3 and 3.4 h in the OOGIB group. When compared with WMC, the GTT and SBTT were significantly faster in both groups (GTT: 3.6 h and SBTT: 4.6 h). The median GTT and SBTT were not significantly different in diabetics vs. non-diabetics [GTT: 17.5 vs. 18.0 min (P = 0.86) and SBTT: 3.9 h (237 min) vs. 3.8 h (230 min), respectively (P = 0.90)]. SBTT as measured using VCE is not significantly different in OOGIB compared with IDA. Both GTT and SBTT are significantly faster as assessed by VCE, which is initiated in the fasting state, compared with WMC measurement, which is initiated after a standard meal. In summary, VCE could potentially be used for measuring SBTT in the fasting state.

  2. Impact of orocecal transit time on patient´s perception of lactose intolerance.

    Science.gov (United States)

    Casellas, Francesc; Aparici, Anna; Casaus, Maite; Rodríguez, Purificación; Malagelada, Juan R

    2013-01-01

    symptoms attributed to the lactose intolerance are an important public health issue because of their prevalence and social relevance. Also because they may cause undue rejection of dairy products consume with potential health consequences. Transit time is a putative factor implied in the severity of symptoms associated with lactose. to elucidate the relation between orocecal transit time (OCTT) and lactose intolerance symptoms. observational study in patients referred to a lactose hydrogen breath test who showed an increase in breath H2 excretion higher than 25 ppm. OCTT was measured with the breath test and symptoms of lactose tolerance with a validated scale. Symptoms were measured twice: before receiving the lactose, inquiring about self perceived symptoms when patients consumed dairy products at home ("home symptoms"), and again after completing the lactose breath test ("test symptoms"). 161 patients were included. There was no correlation between OCTT and home symptoms (r = -0.1). When OCTT was faster than 60 minutes, intensity of "test symptoms" was similar to "home symptoms". However, in patients with normal or slow OCTT, the "home symptoms" were more intense than the "test symptoms" (p lactose test load the symptoms were proportionately more intense with faster OCTT. in lactose maldigesters, selfreported symptoms of lactose intolerance are more pronounced at home than after a high lactose challenge. Intolerance symptoms that patients attributed to lactose consume at home are due to factors other than fast OCTT.

  3. Time response measurements of LASL diagnostic detectors

    International Nuclear Information System (INIS)

    Hocker, L.P.

    1970-07-01

    The measurement and data analysis techniques developed under the Los Alamos Scientific Laboratory's detector improvement program were used to characterize the time and frequency response of selected LASL Compton, fluor-photodiode (NPD), and fluor-photomultiplier (NPM) diagnostic detectors. Data acquisition procedures and analysis methods presently in use are summarized, and detector time and frequency data obtained using the EG and G/AEC electron linear accelerator fast pulse (approximately 50 psec FWHM) as the incident radiation driving function are presented. (U.S.)

  4. Gastrointestinal mean transit times in young and middle-aged healthy subjects

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2001-01-01

    To investigate the effects of age and gender on gastric, small intestinal and colonic mean transit times, a study was conducted in 32 healthy volunteers: eight young women (22-30 years), eight young men (20-28 years), eight middle-aged women (43-51 years) and eight middle-aged men (38-53 years......). After ingestion of a meal containing 111Indium-labelled water and 99mTechnetium-labelled omelette imaging of the abdomen was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric......, small intestinal and colonic mean transit times were calculated. The gastric, small intestinal and colonic mean transit times were significantly longer in women. Ageing was shown to accelerate the gastric and small intestinal transit significantly. In the group of men the colonic mean transit time...

  5. Determination of electron bunch shape using transition radiation and phase-energy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Crosson, E.R.; Berryman, K.W.; Richman, B.A. [Stanford Univ., CA (United States)] [and others

    1995-12-31

    We present data comparing microbunch temporal information obtained from electron beam phase-energy measurements with that obtained from transition radiation auto-correlation measurements. The data was taken to resolve some of the ambiguities in previous transition radiation results. By measuring the energy spectrum of the electron beam as a function of its phase relative to the accelerating field, phase-energy information was extracted. This data was analyzed using tomographic techniques to reconstruct the phase-space distribution assuming an electron energy dependence of E({var_phi}) = E{sub o} + E{sub acc}cos({var_phi}), where E{sub o} is the energy of an electron entering the field, E{sub acc} is the peak energy gain, and {var_phi} is the phase between the crest of the RF wave and an electron. Temporal information about the beam was obtained from the phase space distribution by taking the one dimensional projection along the time axis. We discuss the use of this technique to verify other transition radiation analysis methods.

  6. Determination of electron bunch shape using transition radiation and phase-energy measurements

    International Nuclear Information System (INIS)

    Crosson, E.R.; Berryman, K.W.; Richman, B.A.

    1995-01-01

    We present data comparing microbunch temporal information obtained from electron beam phase-energy measurements with that obtained from transition radiation auto-correlation measurements. The data was taken to resolve some of the ambiguities in previous transition radiation results. By measuring the energy spectrum of the electron beam as a function of its phase relative to the accelerating field, phase-energy information was extracted. This data was analyzed using tomographic techniques to reconstruct the phase-space distribution assuming an electron energy dependence of E(var-phi) = E o + E acc cos(var-phi), where E o is the energy of an electron entering the field, E acc is the peak energy gain, and var-phi is the phase between the crest of the RF wave and an electron. Temporal information about the beam was obtained from the phase space distribution by taking the one dimensional projection along the time axis. We discuss the use of this technique to verify other transition radiation analysis methods

  7. Doppler limited rotational transitions of OH and SH radicals measured by continuous-wave terahertz photomixing

    Science.gov (United States)

    Eliet, Sophie; Martin-Drumel, Marie-Aline; Guinet, Mickaël; Hindle, Francis; Mouret, Gaël; Bocquet, Robin; Cuisset, Arnaud

    2011-12-01

    A continuous-wave terahertz (CW-THz) source generated by photomixing has been employed to detect and quantify radicals produced in a cold plasma probing their spin-rotation transitions. Due to their dual interest for both atmospherists and astrophysicists, the hydroxyl OH and the mercapto SH radicals have been chosen. The photomixing technique which can access the largest range of THz frequencies of any known coherent source, allowed to resolve the Doppler-limited hyperfine transitions of OH in the 2.5 THz frequency region. Line profile analysis of the hyperfine components demonstrated that OH radicals have been detected in this region at a ppm level at a temperature close to 490 K. The hyperfine structure of SH has been resolved for the first time above 1 THz. Ten new frequency transitions have been measured in the 1.3-2.6 THz frequency range using the CW-THz synthesizer based on a frequency comb. With relative uncertainties better than 10 -7, the CW-THz frequencies measured in this study are now competitive with those measured by other instruments such as frequency multiplication chains or FT-FIR spectrometers and are now capable to improve the predictions of the complete high-resolution spectra of these radicals collected in the atmospheric and astrophysical spectroscopic databases. versioncorrigeeAC 2011-07-18 17:32 2011 Arnaud Cuisset.

  8. Using the Life Satisfaction Approach to Value Daylight Savings Time Transitions: Evidence from Britain and Germany

    OpenAIRE

    Daniel Kuehnle; Christoph Wunder

    2015-01-01

    Daylight savings time (DST) represents a public good with costs and benefits. We provide the first comprehensive examination of the welfare effects of the spring and autumn transitions for the UK and Germany. Using individual-level data and a regression discontinuity design, we estimate the effect of the transitions on life satisfaction. Our results show that individuals in both the UK and Germany experience deteriorations in life satisfaction in the first week after the spring transition. We...

  9. Time-resolved brightness measurements by streaking

    Science.gov (United States)

    Torrance, Joshua S.; Speirs, Rory W.; McCulloch, Andrew J.; Scholten, Robert E.

    2018-03-01

    Brightness is a key figure of merit for charged particle beams, and time-resolved brightness measurements can elucidate the processes involved in beam creation and manipulation. Here we report on a simple, robust, and widely applicable method for the measurement of beam brightness with temporal resolution by streaking one-dimensional pepperpots, and demonstrate the technique to characterize electron bunches produced from a cold-atom electron source. We demonstrate brightness measurements with 145 ps temporal resolution and a minimum resolvable emittance of 40 nm rad. This technique provides an efficient method of exploring source parameters and will prove useful for examining the efficacy of techniques to counter space-charge expansion, a critical hurdle to achieving single-shot imaging of atomic scale targets.

  10. Measurement of the population densities in Gd atomic vapor using diode laser absorption spectroscopy in UV transitions

    International Nuclear Information System (INIS)

    Kwon, Duck Hee; Jung, E. C.; Ko, Kwang Hoon; Kim, Tack Soo

    2003-01-01

    We report on the ultraviolet laser absorption spectroscopy of atomic Gd at 394-554 nm where two transition lines are place very closely by using a frequency-doubled beam of external-cavity diode laser (ECDL). One is from 999.121 to 26337.071 cm -1 and the other from 0 to 25337.755 cm -1 . If two transition lines are placed closely within a continuous fine tuning range, the real-time measurement of the atomic excitation temperature is possible without any significant time consumption because at least two transition lines originating from different low-lying energy levels need to be investigated for the Boltzmann-plot. Since the spectral difference between the two transitions is only about 0.195 cm -1 (5.85 GHz), it is possible to record both the absorption spectra simultaneously as shown in Fig. 1. But the transition probabilities (or oscillator strengths) of these lines have not been measured accurately yet to the best of our knowledge. We report on the newly measured transition probabilities by analyzing their absorption spectra at known vapor density conditions. The simultaneous measurement of the atomic excitation temperature and the vapor density demonstrated. In addition we present another ultraviolet laser absorption spectroscopy of atomic Gd at 403.540 nm by means of a commercial blue diode laser and investigate the characteristics of the blue diode laser as well.

  11. Agreement between pre-post measures of change and transition ratings as well as then-tests

    OpenAIRE

    Meyer, Thorsten; Richter, Susanne; Raspe, Heiner

    2013-01-01

    Background Different approaches have been developed for measuring change. Direct measurement of change (transition ratings) requires asking a patient directly about his judgment about the change he has experienced (reported change). With indirect measures of change, the patients? status is assessed at different time points and differences between them are calculated (measured change). When using the quasi-indirect approach (?then-test?), patients are asked after an intervention to rate their ...

  12. A study on the pulmonary mean transit time and the pulmonary blood volume by RI-cardiogram

    International Nuclear Information System (INIS)

    Ushio, Norio

    1987-01-01

    The pulmonary mean transit time and the pulmonary blood volume in cases of cardio-pulmonary disease were measured using Giuntini's method which is considered the most appropriate among radiocardiographic methods. The errors in this method were confirmed to be almost negligible. The results obtained were as follows: 1) The pulmonary mean transit time was related to the systemic mean transit time and markedly prolonged in left heart failure. On the other hand, it was markedly shortened in some cases of chronic pulmonary disease, particularly pulmonary emphysema. 2) The pulmonary blood volume tended to increase in left heart disorders and mitral valve disease and tended to decrease in the chronic pulmonary disease. The decrease was conspicuous particularly in some cases of pulmonary emphysema. 3) A structural change of the pulmonary vascular system in the chronic pulmonary disease appeared to bring about shortening of the pulmonary mean transit time and a decrease in the pulmonary blood volume. The pathophysiology of cardio-pulmonary disease can be more clarified by the RI-cardiogram used in this study, in which the pulmonary mean transit time and the pulmonary blood volume are used as the indicator. (author)

  13. Colonic transit time is related to bacterial metabolism and mucosal turnover in the gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    2016-01-01

    Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transi...... does not per se imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.......Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transit...... time in humans, assessed using radio-opaque markers, is associated with overall gut microbial composition, diversity and metabolism. We find that a long colonic transit time associates with high microbial richness and is accompanied by a shift in colonic metabolism from carbohydrate fermentation...

  14. Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis.

    Science.gov (United States)

    Chiba, Tomoaki; Hino, Hideitsu; Akaho, Shotaro; Murata, Noboru

    2017-01-01

    In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group's sales beat GM's sales, which is a reasonable scenario.

  15. Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis.

    Directory of Open Access Journals (Sweden)

    Tomoaki Chiba

    Full Text Available In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group's sales beat GM's sales, which is a reasonable scenario.

  16. Topological transitions at finite temperatures: A real-time numerical approach

    International Nuclear Information System (INIS)

    Grigoriev, D.Yu.; Rubakov, V.A.; Shaposhnikov, M.E.

    1989-01-01

    We study topological transitions at finite temperatures within the (1+1)-dimensional abelian Higgs model by a numerical simulation in real time. Basic ideas of the real-time approach are presented and some peculiarities of the Metropolis technique are discussed. It is argued that the processes leading to topological transitions are of classical origin; the transitions can be observed by solving the classical field equations in real time. We show that the topological transitions actually pass via the sphaleron configuration. The transition rate as a function of temperature is found to be in good agreement with the analytical predictions. No extra suppression of the rate is observed. The conditions of applicability of our approach are discussed. The temperature interval where the low-temperature broken phase persists is estimated. (orig.)

  17. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    International Nuclear Information System (INIS)

    Le Sage, G P

    2002-01-01

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the beam profile will be described

  18. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    CERN Document Server

    Le Sage, G P

    2002-01-01

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the b...

  19. A Departure Time Choice for Morning Commute Considering Train Capacity of a Rail Transit Line

    OpenAIRE

    Jia Feng; Baohua Mao; Zhijie Chen; Yun Bai; Minggao Li

    2013-01-01

    Every commuter utilizing urban rail transit decides the departure time from home to a station according to individual judgment for the biggest possibility to board a train as soon as possible after the arrival. Therefore, the departure time choice behavior of the commuters is complicated especially when the transport capacity of this transit line cannot meet the travel demands of its users in rush hour. This research first develops a travel cost function mainly considering the travel time to ...

  20. Daylight Savings Time Transitions and the Incidence Rate of Unipolar Depressive Episodes.

    Science.gov (United States)

    Hansen, Bertel T; Sønderskov, Kim M; Hageman, Ida; Dinesen, Peter T; Østergaard, Søren D

    2017-05-01

    Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes. Using time series intervention analysis of nationwide data from the Danish Psychiatric Central Research Register from 1995 to 2012, we compared the observed trend in the incidence rate of hospital contacts for unipolar depressive episodes after the transitions to and from summer time to the predicted trend in the incidence rate. The analyses were based on 185,419 hospital contacts for unipolar depression and showed that the transition from summer time to standard time were associated with an 11% increase (95% CI = 7%, 15%) in the incidence rate of unipolar depressive episodes that dissipated over approximately 10 weeks. The transition from standard time to summer time was not associated with a parallel change in the incidence rate of unipolar depressive episodes. This study shows that the transition from summer time to standard time was associated with an increase in the incidence rate of unipolar depressive episodes. Distress associated with the sudden advancement of sunset, marking the coming of a long period of short days, may explain this finding. See video abstract at, http://links.lww.com/EDE/B179.

  1. Direct and real time probe of photoinduced structure transition in colossal magnetoresistive material

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junjie [Physics Department, Florida State University, Tallahassee, Florida 32310 (United States); National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Wang, Xuan [Institute of physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Zhou, Haidong [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Zhou, Jun; Cao, Jianming, E-mail: jcao@magnet.fsu.edu [Physics Department, Florida State University, Tallahassee, Florida 32310 (United States); National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Cheng, J. G. [Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)

    2016-07-25

    We report a direct and real time measurement of photoinduced structure phase transition in single crystal La{sub 0.84}Sr{sub 0.16}MnO{sub 3} using femtosecond electron diffraction. The melting of orthorhombic lattice ordering under femtosecond optical excitation is found involving two distinct processes with different time scales, an initial fast melting of orthorhombic phase in about 4 ps and a subsequent slower transformation in 90 ps and longer timescales. The fast process is designated as the initial melting of orthorhombic phase induced by the Mn-O bond change that is most likely driven by the quenching of the dynamic Jahn-Teller distortion following the photo-excitation. The slow process is attributed to the growing of newly formed structure domain from the photo-excited sites to the neighboring non-excited orthorhombic sites.

  2. Time-delay-induced phase-transition to synchrony in coupled bursting neurons

    Science.gov (United States)

    Adhikari, Bhim Mani; Prasad, Awadhesh; Dhamala, Mukeshwar

    2011-06-01

    Signal transmission time delays in a network of nonlinear oscillators are known to be responsible for a variety of interesting dynamic behaviors including phase-flip transitions leading to synchrony or out of synchrony. Here, we uncover that phase-flip transitions are general phenomena and can occur in a network of coupled bursting neurons with a variety of coupling types. The transitions are marked by nonlinear changes in both temporal and phase-space characteristics of the coupled system. We demonstrate these phase-transitions with Hindmarsh-Rose and Leech-Heart interneuron models and discuss the implications of these results in understanding collective dynamics of bursting neurons in the brain.

  3. Measurements of a vortex transitional ndro Josephson memory cell

    International Nuclear Information System (INIS)

    Tahara, S.; Ishida, I.; Hidaka, M.; Nagasawa, S.; Ajisawa, Y.; Wada, Y.

    1988-01-01

    A novel vortex transitional NDRO Jospehson memory cell has been successfully fabricated and tested. The memory cell consists of two superconducting loops and a two-junction interferometer gate as a sense gate. The superconducting loop contains one Josephson junction and inductances, and stores single flux quantum. The memory cell employs vortex transitions in the superconducting loops for writing and reading data. The memory cell chips have been fabricated using niobium planarization process. The +-21 percent address signal current margin and the +-33 percent sense gate current margin have been obtained experimentally. The memory operation of the cell driven by the two-junction interferometer gates has been accurately demonstrated

  4. Are anomalously short tunnelling times measurable?

    International Nuclear Information System (INIS)

    Delgado, V.; Muga, J.G.

    1996-01-01

    Low and Mende have analyzed the conditions that would make possible an actual measurement of an anomalously short traversal time through a potential barrier concluding that such a measurement cannot be made because it is not possible to describe the tunnelling of a wave packet initially close to the barrier by the open-quote open-quote usual wave packet space time analysis close-quote close-quote. We complement this work in several ways: It is argued that the described failure of the usual formalism occurs under a set of too restrictive conditions, some of them not physically motivated, so it does not necessarily imply the impossibility of such a measurement. However, by retaining only conditions well motivated on physical grounds we have performed a systematic numerical check which shows that the conclusion by Low and Mende is indeed generally valid. It is shown that, as speculated by Low and Mende, the process is dominated by over the barrier transmission. Copyright copyright 1996 Academic Press, Inc

  5. Time Resolved Deposition Measurements in NSTX

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Roquemore, A.L.; Hogan, J.; Wampler, W.R.

    2004-01-01

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm 2 of deposition, however surprisingly, 15.9 (micro)g/cm 2 of material loss occurred at 7 discharges. The net deposited mass of 13.3 (micro)g/cm 2 matched the mass of 13.5 (micro)g/cm 2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition

  6. Tile Surface Thermocouple Measurement Challenges from the Orbiter Boundary Layer Transition Flight Experiment

    Science.gov (United States)

    Campbell, Charles H.; Berger, Karen; Anderson, Brian

    2012-01-01

    Hypersonic entry flight testing motivated by efforts seeking to characterize boundary layer transition on the Space Shuttle Orbiters have identified challenges in our ability to acquire high quality quantitative surface temperature measurements versus time. Five missions near the end of the Space Shuttle Program implemented a tile surface protuberance as a boundary layer trip together with tile surface thermocouples to capture temperature measurements during entry. Similar engineering implementations of these measurements on Discovery and Endeavor demonstrated unexpected measurement voltage response during the high heating portion of the entry trajectory. An assessment has been performed to characterize possible causes of the issues experienced during STS-119, STS-128, STS-131, STS-133 and STS-134 as well as similar issues encountered during other orbiter entries.

  7. Transitions in the computational power of thermal states for measurement-based quantum computation

    International Nuclear Information System (INIS)

    Barrett, Sean D.; Bartlett, Stephen D.; Jennings, David; Doherty, Andrew C.; Rudolph, Terry

    2009-01-01

    We show that the usefulness of the thermal state of a specific spin-lattice model for measurement-based quantum computing exhibits a transition between two distinct 'phases' - one in which every state is a universal resource for quantum computation, and another in which any local measurement sequence can be simulated efficiently on a classical computer. Remarkably, this transition in computational power does not coincide with any phase transition, classical, or quantum in the underlying spin-lattice model.

  8. Transiting Exoplanet Monitoring Project (TEMP). IV. Refined System Parameters, Transit Timing Variations, and Orbital Stability of the Transiting Planetary System HAT-P-25

    Science.gov (United States)

    Wang, Xian-Yu; Wang, Songhu; Hinse, Tobias C.; Li, Kai; Wang, Yong-Hao; Laughlin, Gregory; Liu, Hui-Gen; Zhang, Hui; Wu, Zhen-Yu; Zhou, Xu; Zhou, Ji-Lin; Hu, Shao-Ming; Wu, Dong-Hong; Peng, Xi-Yan; Chen, Yuan-Yuan

    2018-06-01

    We present eight new light curves of the transiting extra-solar planet HAT-P-25b obtained from 2013 to 2016 with three telescopes at two observatories. We use the new light curves, along with recent literature material, to estimate the physical and orbital parameters of the transiting planet. Specifically, we determine the mid-transit times (T C ) and update the linear ephemeris, T C[0] = 2456418.80996 ± 0.00025 [BJDTDB] and P = 3.65281572 ± 0.00000095 days. We carry out a search for transit timing variations (TTVs), and find no significant TTV signal at the ΔT = 80 s-level, placing a limit on the possible strength of planet–planet interactions (TTVG). In the course of our analysis, we calculate the upper mass-limits of the potential nearby perturbers. Near the 1:2, 2:1, and 3:1 resonances with HAT-P-25b, perturbers with masses greater than 0.5, 0.3, and 0.5 M ⊕ respectively, can be excluded. Furthermore, based on the analysis of TTVs caused by light travel time effect (LTTE) we also eliminate the possibility that a long-period perturber exists with M p > 3000 MJ within a = 11.2 au of the parent star.

  9. Critical capacity, travel time delays and travel time distribution of rapid mass transit systems

    Science.gov (United States)

    Legara, Erika Fille; Monterola, Christopher; Lee, Kee Khoon; Hung, Gih Guang

    2014-07-01

    We set up a mechanistic agent-based model of a rapid mass transit system. Using empirical data from Singapore's unidentifiable smart fare card, we validate our model by reconstructing actual travel demand and duration of travel statistics. We subsequently use this model to investigate two phenomena that are known to significantly affect the dynamics within the RTS: (1) overloading in trains and (2) overcrowding in the RTS platform. We demonstrate that by varying the loading capacity of trains, a tipping point emerges at which an exponential increase in the duration of travel time delays is observed. We also probe the impact on the rail system dynamics of three types of passenger growth distribution across stations: (i) Dirac delta, (ii) uniform and (iii) geometric, which is reminiscent of the effect of land use on transport. Under the assumption of a fixed loading capacity, we demonstrate the dependence of a given origin-destination (OD) pair on the flow volume of commuters in station platforms.

  10. Shock timing measurements in DT ice layers

    Science.gov (United States)

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

    2013-10-01

    Shock timing experiments on the National Ignition Facility (NIF) are routinely conducted using the keyhole target geometry, in which the strength and timing of multiple shocks are measured in a liquid-deuterium (D2) filled capsule interior. These targets have recently been modified to improve the surrogacy to ignition implosions by replacing the standard, continuous liquid D2 capsule fill with a deuterium-tritium (DT) ice layer with a central DT gas fill. These experiments remove any possible material surrogacy difference between D2 and DT as well as incorporating the physics of multiple shock release and recompression events from an ice layer of finite thickness, an effect that is absent in the liquid-filled targets. Experimental results and comparisons with numerical simulation are presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

  11. Leak rate measurements on bimetallic transition samples for ILC cryomodules

    International Nuclear Information System (INIS)

    Budagov, Yu.; Chernikov, A.; Sabirov, B.

    2008-01-01

    The results of leak test of bimetallic (titanium-stainless steel) transition elements produced by explosion welding are presented. Vacuum and high-pressure tests of the sample for leakage were carried out at room temperature and liquid nitrogen temperature. Similar tests were also carried out under thermal cycling conditions

  12. First-time viewers' comprehension of films: bridging shot transitions.

    Science.gov (United States)

    Ildirar, Sermin; Schwan, Stephan

    2015-02-01

    Which perceptual and cognitive prerequisites must be met in order to be able to comprehend a film is still unresolved and a controversial issue. In order to gain some insights into this issue, our field experiment investigates how first-time adult viewers extract and integrate meaningful information across film cuts. Three major types of commonalities between adjacent shots were differentiated, which may help first-time viewers with bridging the shots: pictorial, causal, and conceptual. Twenty first-time, 20 low-experienced and 20 high-experienced viewers from Turkey were shown a set of short film clips containing these three kinds of commonalities. Film clips conformed also to the principles of continuity editing. Analyses of viewers' spontaneous interpretations show that first-time viewers indeed are able to notice basic pictorial (object identity), causal (chains of activity), as well as conceptual (links between gaze direction and object attention) commonalities between shots due to their close relationship with everyday perception and cognition. However, first-time viewers' comprehension of the commonalities is to a large degree fragile, indicating the lack of a basic notion of what constitutes a film. © 2014 The British Psychological Society.

  13. Sport Transition of JPSS VIIRS Imagery for Night-time Applications

    Science.gov (United States)

    Fuell, Kevin; LeRoy, Anita; Smith, Matt; Miller, Steve; Kann, Diedre; Bernhardt, David; Reydell, Nezette; Cox, Robert

    2014-01-01

    The NASA/Short-term Prediction, Research, and Transition (SPoRT) Program and NOAA/Cooperative Institute for Research in the Atmosphere (CIRA) work within the NOAA/Joint Polar Satellite System (JPSS) Proving Ground to demonstrate the unique capabilities of the VIIRS instrument. Very similar to MODIS, the VIIRS instrument provides many high-resolution visible and infrared channels in a broad spectrum. In addition, VIIRS is equipped with a low-light sensor that is able to detect light emissions from the land and atmosphere as well as reflected sunlight by the lunar surface. This band is referred to as the Day-Night Band due to the sunlight being used at night to see cloud and topographic features just as one would typically see in day-time visible imagery. NWS forecast offices that collaborate with SPoRT and CIRA have utilized MODIS imagery in operations, but have longed for more frequent passes of polar-orbiting data. The VIIRS instrument enhances SPoRT collaborations with WFOs by providing another day and night-time pass, and at times two additional passes due to its large swath width. This means that multi-spectral, RGB imagery composites are more readily available to prepare users for their use in GOES-R era and high-resolution imagery for use in high-latitudes is more frequently able to supplement standard GOES imagery within the SPoRT Hybrid GEO-LEO product. The transition of VIIRS also introduces the new Day-Night Band capability to forecast operations. An Intensive Evaluation Period (IEP) was conducted in Summer 2013 with a group of "Front Range" NWS offices related to VIIRS night-time imagery. VIIRS single-channel imagery is able to better analyze the specific location of fire hotspots and other land features, as well as provide a more true measurement of various cloud and aerosol properties than geostationary measurements, especially at night. Viewed within the SPoRT Hybrid imagery, the VIIRS data allows forecasters to better interpret the more frequent, but

  14. Analysis in measurements of gastric emptying time

    International Nuclear Information System (INIS)

    Lee, Choon Ho; Lee, Man Koo

    1997-01-01

    Scintigraphic measurement of gastric emptying time has been reported to be influenced by the variation in depth of radionuclide within the stomach. This study was designed to clarify whether a part of the variability in gastric emptying could be ascribed to a relationship between anterior image, the total anteroposterior image and the tissue attenuation correction(geometric mean). A dual-head scintillation camera(ADAC, USA) was used to investigate effect of such changes. We were performed 16 normal subject gastric emptying studies with 99 mTC labelled scramble egg, milk and solid meal(610 Kcal, 300 g). The results are as follows; On anterior image, T 1/2 emptying time was delayed by 5 min, 6.5%(range : 3 ∼ 18 min, 5∼31.4%) compared with the geometric mean. But there was no different gastric emptying time between the total anteroposterior image and geometric mean. Therefore, if will be useful to use the method of geometric mean or the total anteroposterior image to evaluate the gastric emptying time accurately

  15. Analysis in measurements of gastric emptying time

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choon Ho [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of); Lee, Man Koo [Wonkwang Health Science College, Iksan (Korea, Republic of)

    1997-02-01

    Scintigraphic measurement of gastric emptying time has been reported to be influenced by the variation in depth of radionuclide within the stomach. This study was designed to clarify whether a part of the variability in gastric emptying could be ascribed to a relationship between anterior image, the total anteroposterior image and the tissue attenuation correction(geometric mean). A dual-head scintillation camera(ADAC, USA) was used to investigate effect of such changes. We were performed 16 normal subject gastric emptying studies with {sup 99}mTC labelled scramble egg, milk and solid meal(610 Kcal, 300 g). The results are as follows; On anterior image, T{sub 1/2} emptying time was delayed by 5 min, 6.5%(range : 3 {approx} 18 min, 5{approx}31.4%) compared with the geometric mean. But there was no different gastric emptying time between the total anteroposterior image and geometric mean. Therefore, if will be useful to use the method of geometric mean or the total anteroposterior image to evaluate the gastric emptying time accurately.

  16. Time-Lapse Measurement of Wellbore Integrity

    Science.gov (United States)

    Duguid, A.

    2017-12-01

    Well integrity is becoming more important as wells are used longer or repurposed. For CO2, shale gas, and other projects it has become apparent that wells represent the most likely unintended migration pathway for fluids out of the reservoir. Comprehensive logging programs have been employed to determine the condition of legacy wells in North America. These studies provide examples of assessment technologies. Logging programs have included pulsed neutron logging, ultrasonic well mapping, and cement bond logging. While these studies provide examples of what can be measured, they have only conducted a single round of logging and cannot show if the well has changed over time. Recent experience with time-lapse logging of three monitoring wells at a US Department of Energy sponsored CO2 project has shown the full value of similar tools. Time-lapse logging has shown that well integrity changes over time can be identified. It has also shown that the inclusion of and location of monitoring technologies in the well and the choice of construction materials must be carefully considered. Two of the wells were approximately eight years old at the time of study; they were constructed with steel and fiberglass casing sections and had lines on the outside of the casing running to the surface. The third well was 68 years old when it was studied and was originally constructed as a production well. Repeat logs were collected six or eight years after initial logging. Time-lapse logging showed the evolution of the wells. The results identified locations where cement degraded over time and locations that showed little change. The ultrasonic well maps show clearly that the lines used to connect the monitoring technology to the surface are visible and have a local effect on cement isolation. Testing and sampling was conducted along with logging. It provided insight into changes identified in the time-lapse log results. Point permeability testing was used to provide an in-situ point

  17. Methods for Detecting Early Warnings of Critical Transitions in Time Series Illustrated Using Simulated Ecological Data

    Science.gov (United States)

    Dakos, Vasilis; Carpenter, Stephen R.; Brock, William A.; Ellison, Aaron M.; Guttal, Vishwesha; Ives, Anthony R.; Kéfi, Sonia; Livina, Valerie; Seekell, David A.; van Nes, Egbert H.; Scheffer, Marten

    2012-01-01

    Many dynamical systems, including lakes, organisms, ocean circulation patterns, or financial markets, are now thought to have tipping points where critical transitions to a contrasting state can happen. Because critical transitions can occur unexpectedly and are difficult to manage, there is a need for methods that can be used to identify when a critical transition is approaching. Recent theory shows that we can identify the proximity of a system to a critical transition using a variety of so-called ‘early warning signals’, and successful empirical examples suggest a potential for practical applicability. However, while the range of proposed methods for predicting critical transitions is rapidly expanding, opinions on their practical use differ widely, and there is no comparative study that tests the limitations of the different methods to identify approaching critical transitions using time-series data. Here, we summarize a range of currently available early warning methods and apply them to two simulated time series that are typical of systems undergoing a critical transition. In addition to a methodological guide, our work offers a practical toolbox that may be used in a wide range of fields to help detect early warning signals of critical transitions in time series data. PMID:22815897

  18. Takeover Time in Highly Automated Vehicles: Noncritical Transitions to and From Manual Control.

    Science.gov (United States)

    Eriksson, Alexander; Stanton, Neville A

    2017-06-01

    The aim of this study was to review existing research into driver control transitions and to determine the time it takes drivers to resume control from a highly automated vehicle in noncritical scenarios. Contemporary research has moved from an inclusive design approach to adhering only to mean/median values when designing control transitions in automated driving. Research into control transitions in highly automated driving has focused on urgent scenarios where drivers are given a relatively short time span to respond to a request to resume manual control. We found a paucity in research into more frequent scenarios for control transitions, such as planned exits from highway systems. Twenty-six drivers drove two scenarios with an automated driving feature activated. Drivers were asked to read a newspaper, or to monitor the system, and to relinquish, or resume, control from the automation when prompted by vehicle systems. Significantly longer control transition times were found between driving with and without secondary tasks. Control transition times were substantially longer than those reported in the peer-reviewed literature. We found that drivers take longer to resume control when under no time pressure compared with that reported in the literature. Moreover, we found that drivers occupied by a secondary task exhibit larger variance and slower responses to requests to resume control. Workload scores implied optimal workload. Intra- and interindividual differences need to be accommodated by vehicle manufacturers and policy makers alike to ensure inclusive design of contemporary systems and safety during control transitions.

  19. γ-γ directional angular correlations measurements for transitions in 140 Ce

    International Nuclear Information System (INIS)

    Zamboni, C.B.; Lapolli, A.L.; Silva Figueira, M.C. da; Yoneama, M.L.; Dias, J.F.; Medeiros, J.A.G. de.

    1990-01-01

    The directional correlations of coincident gamma transitions have been measured in 140 Ce following the β - decay of 140 La, with T 1/2 = 40,3 hs, using a spectrometer consisting of two Ge detectors. The measurements were carried out for 8 gamma cascades and the multipole mixing ratios, δ, for the majority gamma transitions were extracted from the present results. (author)

  20. Determination of the full polarimetric transition matrix of a magnetized plasma from measurements of phase only

    International Nuclear Information System (INIS)

    Segre, S.E.

    1996-09-01

    It is shown that, by using a convenient modulated input polarization, it is possible to determine the full plasma polarimetric transition matrix purely from phase measurements. These are advantageous compared to previously proposed amplitude measurements. Two alternative sets of configurations for the input polarization are considered. The elements of the transition matrix thus found can be used in the reconstruction of the MHD equilibrium

  1. Noncontact sphygmomanometer based on pulse-wave transit time between the face and hand

    Science.gov (United States)

    Nakano, Kazuya; Ohnishi, Takashi; Nishidate, Izumi; Haneishi, Hideaki

    2018-02-01

    Systolic blood pressure (SBP) is highly sensitive to various factors such as psychological stress, and hence its continuous monitoring is essential to evaluate different health conditions. However, conventional sphygmomanometers cannot continuously measure SBP given the time-consuming setup based on a pressure cuff. Moreover, continuous biological signal monitoring is more comfortable when no sensors are attached. A solution for continuous SBP estimation is based on pulse transit time (PTT), which determines the time difference between two pulse waves at different body parts. In previous studies, we successfully measured the PTT using a contactless setup composed by two digital color cameras recording the face and hand of subjects. Then, the acquired images were transformed into blood volume by combining multiple regression analysis and a Monte Carlo method. As a result, the delay among images allowed to determine the PPT from pulse waves. In this study, we simultaneously measured SBP and PTT by using a sphygmomanometer and the two cameras, respectively. We evaluated SBP increases (i.e., stressful situations) and the corresponding PPT by asking participants to either grasp a handgrip or momentarily interrupting breath. We also determined the SBP and PTT without asking for such exercises. Comparison results show that the mean PTT under stress was significantly lower than that without stress, which is consistent with an increased SBP. Finally, we related the SBP and PTT by a nonlinear formula with a coefficient of determination of 0.59, thus confirming the effectiveness of the proposed system.

  2. Ellipsometry measurements of glass transition breadth in bulk films of random, block, and gradient copolymers.

    Science.gov (United States)

    Mok, M M; Kim, J; Marrou, S R; Torkelson, J M

    2010-03-01

    Bulk films of random, block and gradient copolymer systems were studied using ellipsometry to demonstrate the applicability of the numerical differentiation technique pioneered by Kawana and Jones for studying the glass transition temperature (T (g)) behavior and thermal expansivities of copolymers possessing different architectures and different levels of nanoheterogeneity. In a series of styrene/n -butyl methacrylate (S/nBMA) random copolymers, T (g) breadths were observed to increase from approximately 17( degrees ) C in styrene-rich cases to almost 30( degrees ) C in nBMA-rich cases, reflecting previous observations of significant nanoheterogeneity in PnBMA homopolymers. The derivative technique also revealed for the first time a substantial increase in glassy-state expansivity with increasing nBMA content in S/nBMA random copolymers, from 1.4x10(-4) K-1 in PS to 3.5x10(-4) K-1 in PnBMA. The first characterization of block copolymer T (g) 's and T (g) breadths by ellipsometry is given, examining the impact of nanophase-segregated copolymer structure on ellipsometric measurements of glass transition. The results show that, while the technique is effective in detecting the two T (g) 's expected in certain block copolymer systems, the details of the glass transition can become suppressed in ellipsometry measurements of a rubbery minor phase under conditions where the matrix is glassy; meanwhile, both transitions are easily discernible by differential scanning calorimetry. Finally, broad glass transition regions were measured in gradient copolymers, yielding in some cases extraordinary T (g) breadths of 69- 71( degrees ) C , factors of 4-5 larger than the T (g) breadths of related homopolymers and random copolymers. Surprisingly, one gradient copolymer demonstrated a slightly narrower T (g) breadth than the S/nBMA random copolymers with the highest nBMA content. This highlights the fact that nanoheterogeneity relevant to the glass transition response in selected

  3. Postfoundational practical theology for a time of transition

    African Journals Online (AJOL)

    Test

    2010-09-01

    Sep 1, 2010 ... Since 1990, I was involved in full time teaching and my focus was on pastoral narrative therapy. .... a balance between 'the way our beliefs are anchored in .... But couldn't we ourselves, each one of us, make our life a work.

  4. Laminar microvascular transit time distribution in the mouse somatosensory cortex revealed by Dynamic Contrast Optical Coherence Tomography.

    Science.gov (United States)

    Merkle, Conrad W; Srinivasan, Vivek J

    2016-01-15

    The transit time distribution of blood through the cerebral microvasculature both constrains oxygen delivery and governs the kinetics of neuroimaging signals such as blood-oxygen-level-dependent functional Magnetic Resonance Imaging (BOLD fMRI). However, in spite of its importance, capillary transit time distribution has been challenging to quantify comprehensively and efficiently at the microscopic level. Here, we introduce a method, called Dynamic Contrast Optical Coherence Tomography (DyC-OCT), based on dynamic cross-sectional OCT imaging of an intravascular tracer as it passes through the field-of-view. Quantitative transit time metrics are derived from temporal analysis of the dynamic scattering signal, closely related to tracer concentration. Since DyC-OCT does not require calibration of the optical focus, quantitative accuracy is achieved even deep in highly scattering brain tissue where the focal spot degrades. After direct validation of DyC-OCT against dilution curves measured using a fluorescent plasma label in surface pial vessels, we used DyC-OCT to investigate the transit time distribution in microvasculature across the entire depth of the mouse somatosensory cortex. Laminar trends were identified, with earlier transit times and less heterogeneity in the middle cortical layers. The early transit times in the middle cortical layers may explain, at least in part, the early BOLD fMRI onset times observed in these layers. The layer-dependencies in heterogeneity may help explain how a single vascular supply manages to deliver oxygen to individual cortical layers with diverse metabolic needs. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Out-of-equilibrium dynamics driven by localized time-dependent perturbations at quantum phase transitions

    Science.gov (United States)

    Pelissetto, Andrea; Rossini, Davide; Vicari, Ettore

    2018-03-01

    We investigate the quantum dynamics of many-body systems subject to local (i.e., restricted to a limited space region) time-dependent perturbations. If the system crosses a quantum phase transition, an off-equilibrium behavior is observed, even for a very slow driving. We show that, close to the transition, time-dependent quantities obey scaling laws. In first-order transitions, the scaling behavior is universal, and some scaling functions can be computed exactly. For continuous transitions, the scaling laws are controlled by the standard critical exponents and by the renormalization-group dimension of the perturbation at the transition. Our protocol can be implemented in existing relatively small quantum simulators, paving the way for a quantitative probe of the universal off-equilibrium scaling behavior, without the need to manipulate systems close to the thermodynamic limit.

  6. New measurements of spontaneous transition probabilities for beryllium-like ions

    International Nuclear Information System (INIS)

    Lang, J.; Hardcastle, R.A.; McWhirter, R.W.P.; Spurrett, P.H.

    1986-06-01

    The authors describe measurements of spectral line intensities for pairs of transitions having common upper levels and thus derive the branching ratios of their spontaneous radiative transition probabilities. These are then combined with the results of measurements of the radiative lifetimes of the upper levels by other authors to obtain values of the individual transition probabilities. The results are for transitions in NIV, OV and NeVII and are given with a claimed accuracy of between 7% and 38%. These are compared with values calculated theoretically. For some of the simpler electric dipole transitions good agreement is found. On the other hand for some of the other transitions which in certain cases are only possible because of configuration interaction disparities between the present measurements and theory are as large as x5. (author)

  7. CMS High Level Trigger Timing Measurements

    International Nuclear Information System (INIS)

    Richardson, Clint

    2015-01-01

    The two-level trigger system employed by CMS consists of the Level 1 (L1) Trigger, which is implemented using custom-built electronics, and the High Level Trigger (HLT), a farm of commercial CPUs running a streamlined version of the offline CMS reconstruction software. The operational L1 output rate of 100 kHz, together with the number of CPUs in the HLT farm, imposes a fundamental constraint on the amount of time available for the HLT to process events. Exceeding this limit impacts the experiment's ability to collect data efficiently. Hence, there is a critical need to characterize the performance of the HLT farm as well as the algorithms run prior to start up in order to ensure optimal data taking. Additional complications arise from the fact that the HLT farm consists of multiple generations of hardware and there can be subtleties in machine performance. We present our methods of measuring the timing performance of the CMS HLT, including the challenges of making such measurements. Results for the performance of various Intel Xeon architectures from 2009-2014 and different data taking scenarios are also presented. (paper)

  8. Characterisation of cerebral blood flow via determining the vascular mean transit time

    International Nuclear Information System (INIS)

    Lindner, P.; Thelen, M.

    1987-01-01

    By using a recently developed algorithm it is possible to quantify the dynamic information of a DSA sequence of the brain. The theory of algorithm allows to calculate vascular mean transit from time density curves. The algorithm minimizes the problems of densitometry with regard to 'quantitative DSA'. There is a strong correlation between vascular mean transit times and cerebral blood flow values, and therefore the results for mean transit times also correspond to the results obtained for cerebral blood flow. By computerized postprocessing of DSA-images it is possible to generate functional images of the brain with a spatial resolution that had not been attainable so far. The images represent the distribution pattern of reverse vascular mean transit times. The results from 36 patients with proven stenoses of the cervical vessels are reported. (orig.) [de

  9. Calculation model for 16N transit time in the secondary side of steam generators

    International Nuclear Information System (INIS)

    Liu Songyu; Xu Jijun; Xu Ming

    1998-01-01

    The 16 N transit time is essential to determine the leak-rate of steam generator tubes leaks with 16 N monitoring system, which is a new technique. A model was developed for calculation 16 N transit time in the secondary side of steam generators. According to the flow characters of secondary side fluid, the transit times divide into four sectors from tube sheet to the sensor on steam line. The model assumes that 16 N is moving as vapor phase in the secondary-side. So the model for vapor velocity distribution in tube bundle is presented in detail. The 16 N transit time calculation results of this model compare with these of EDF on steam generator of Qinshan NPP

  10. The transition time induced narrow linewidth of the electromagnetically induced transparency in caesium vapour

    International Nuclear Information System (INIS)

    Li Luming; Peng Xiang; Liu Cheng; Guo Hong; Chen Xuzong

    2004-01-01

    We observed a narrow linewidth (∼60 kHz) in a Doppler-broadened system showing electromagnetically induced transparency in caesium atomic vapour. The transition time induced reduction of the linewidth is illustrated both theoretically and experimentally

  11. Relationships between rumination time, metabolic conditions, and health status in dairy cows during the transition period.

    Science.gov (United States)

    Soriani, N; Trevisi, E; Calamari, L

    2012-12-01

    The main objective of this experiment was to monitor the rumination pattern during the transition period in primiparous (PR) and pluriparous (PL) dairy cows and to investigate its relationships with metabolic conditions, milk yield, and health status. The study was carried out in an experimental free-stall barn and involved 32 Italian Friesian cows (9 PR and 23 PL) during the transition phase. The rumination time (RT) was recorded with an automatic system (HR-Tag), and data were calculated and summarized in 2-h intervals. Blood samples were collected during the transition phase to assess biochemical variables related to energy, protein, and mineral metabolism, as well as markers of inflammatory conditions and some enzyme activity. Daily milk yield, BW, nutritional condition, and health status were also recorded. The average RT before calving (-20 to -6 d) was 463 min/d in PR (range 270 to 620) and 522 min/d in PL (range 411 to 640). In the early lactation [15 to 40 d in milk (DIM)], the average RT was 504 min/d in PR (range 400 to 585) and 562 min/d in PL (range 414 to 685) and was positively correlated with milk yield (r = 0.36; P Cows with reduced RT before calving maintained reduced RT after calving and suffered a greater frequency of disease than cows with greater RT in late pregnancy. Moreover, cows characterized by mild inflammatory conditions and without health disorders or only mild health disorders during the puerperium showed a greater average rumination time (over 520 min/d) during the first 10 d of lactation. Conversely, the decreased RT (450 min/d) during the first few days of lactation was observed in cows with subclinical diseases or health disorders. Cows affected by clinical mastitis during the trial showed a reduction of RT and a change in its variability already some days before the drug treatment. Our results suggest that the automatic measurement of RT is useful to predict calving time and to quickly obtain information on health status of the

  12. Dating of streamwater using tritium in a post nuclear bomb pulse world: continuous variation of mean transit time with streamflow

    Directory of Open Access Journals (Sweden)

    U. Morgenstern

    2010-11-01

    Full Text Available Tritium measurements of streamwater draining the Toenepi catchment, a small dairy farming area in Waikato, New Zealand, have shown that the mean transit time of the water varies with the flow rate of the stream. Mean transit times through the catchment are 2–5 years during high baseflow conditions in winter, increasing to 30–40 years as baseflow decreases in summer, and then dramatically older water during drought conditions with mean transit time of more than 100 years. Older water is gained in the lower reaches of the stream, compared to younger water in the headwater catchment. The groundwater store supplying baseflow was estimated from the mean transit time and average baseflow to be 15.4 × 106 m3 of water, about 1 m water equivalent over the catchment and 2.3 times total annual streamflow. Nitrate is relatively high at higher flow rates in winter, but is low at times of low flow with old water. This reflects both lower nitrate loading in the catchment several decades ago as compared to current intensive dairy farming, and denitrification processes occurring in the older groundwater. Silica, leached from the aquifer material and accumulating in the water in proportion to contact time, is high at times of low streamflow with old water. There was a good correlation between silica concentration and streamwater age, which potentially allows silica concentrations to be used as a proxy for age when calibrated by tritium measurements. This study shows that tritium dating of stream water is possible with single tritium measurements now that bomb-test tritium has effectively disappeared from hydrological systems in New Zealand, without the need for time-series data.

  13. Neutral Pion Transition Form Factor Measurement and Run Control at the NA62 experiment

    CERN Document Server

    AUTHOR|(CDS)2082375; Goudzovski, Evgueni

    The measurement of the 0 electromagnetic transition form factor (TFF) slope a is performed in the time-like region of momentum transfer using a sample of 1.1 $10^6$ $\\pi^0 \\to e^+ e^- \\gamma$ Dalitz decays collected at the NA62-RK experiment in 2007. The event selection, the fit procedure and the study of the systematic ffects are presented. The final result obtained $a = (3.68 \\pm 0.51stat \\pm 0.25syst) \\times 10^{-2} $ is the most precise to date and represents the first evidence of a non-zero $\\pi^0$ TFF slope with more than 3 $\\sigma$ significance. The NA62 experiment based at the CERN SPS is currently taking data and aims at measuring the branching fraction of the $K \\to \\pi \

  14. Using Dielectric Relaxation Spectroscopy to Characterize the Glass Transition Time of Polydextrose.

    Science.gov (United States)

    Buehler, Martin G; Kindle, Michael L; Carter, Brady P

    2015-06-01

    Dielectric relaxation spectroscopy was used to characterize the glass transition time, tg , of polydextrose, where the glass transition temperature, Tg , and water activity, aw (relative humidity), were held constant during polydextrose relaxation. The tg was determined from a shift in the peak frequency of the imaginary capacitance spectrum with time. It was found that when the peak frequency reaches 30 mHz, polydextrose undergoes glass transition. Glass transition time, tg , is the time for polydextrose to undergo glass transition at a specific Tg and aw . Results lead to a modified state diagram, where Tg is depressed with increasing aw . This curve forms a boundary: (a) below the boundary, polydextrose does not undergo glass transition and (b) above the boundary, polydextrose rapidly undergoes glass transition. As the boundary curve is specified by a tg value, it can assist in the selection of storage conditions. An important point on the boundary curve is at aw = 0, where Tg0 = 115 °C. The methodology can also be used to calculate the stress-relaxation viscosity of polydextrose as a function of Tg and aw , which is important when characterizing the flow properties of polydextrose initially in powder form. © 2015 Institute of Food Technologists®

  15. Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans.

    OpenAIRE

    El Oufir, L; Flourié, B; Bruley des Varannes, S; Barry, J L; Cloarec, D; Bornet, F; Galmiche, J P

    1996-01-01

    BACKGROUND/AIMS: To investigate whether transit time could influence H2 consuming flora and certain indices of colonic bacterial fermentation. METHODS: Eight healthy volunteers (four methane excretors and four non-methane excretors) were studied for three, three week periods during which they received a controlled diet alone (control period), and then the same diet with cisapride or loperamide. At the end of each period, mean transit time (MTT) was estimated, an H2 lactulose breath test was p...

  16. Total and segmental colon transit time in constipated children assessed by scintigraphy with 111In-DTPA given orally.

    Science.gov (United States)

    Vattimo, A; Burroni, L; Bertelli, P; Messina, M; Meucci, D; Tota, G

    1993-12-01

    Serial colon scintigraphy using 111In-DTPA (2 MBq) given orally was performed in 39 children referred for constipation, and the total and segmental colon transit times were measured. The bowel movements during the study were recorded and the intervals between defecations (ID) were calculated. This method proved able to identify children with normal colon morphology (no. = 32) and those with dolichocolon (no. = 7). Normal children were not included for ethical reasons and we used the normal range determined by others using x-ray methods (29 +/- 4 hours). Total and segmental colon transit times were found to be prolonged in all children with dolichocolon (TC: 113.55 +/- 41.20 hours; RC: 39.85 +/- 26.39 hours; LC: 43.05 +/- 18.30 hours; RS: 30.66 +/- 26.89 hours). In the group of children with a normal colon shape, 13 presented total and segmental colon transit times within the referred normal value (TC: 27.79 +/- 4.10 hours; RC: 9.11 +/- 2.53 hours; LC: 9.80 +/- 3.50 hours; RS: 8.88 +/- 4.09 hours) and normal bowel function (ID: 23.37 +/- 5.93 hours). In the remaining children, 5 presented prolonged retention in the rectum (RS: 53.36 +/- 29.66 hours), and 14 a prolonged transit time in all segments. A good correlation was found between the transit time and bowel function. From the point of view of radiation dosimetry, the most heavily irradiated organs were the lower large intestine and the ovaries, and the level of radiation burden depended on the colon transit time. We can conclude that the described method results safe, accurate and fully diagnostic.

  17. Scintigraphic Small Intestinal Transit Time and Defaecography in Patients with J-Pouch

    Directory of Open Access Journals (Sweden)

    Mie Dilling Kjaer

    2015-10-01

    Full Text Available Objective methods for examination of pouch function are warranted for a better understanding of the functional result and treatment of dysfunction. The objective of this study was to evaluate the results of scintigraphic intestinal transit time and defaecography compared to the results of pouch function, mucosal condition and a questionnaire on quality of life (QoL. This cross-sectional study included 21 patients. Scintigraphic transit time and defaecography was determined with the use of Tc-99m. Pouch function was assessed by number of bowel movements, pouch volume, and continence. Pouch mucosal condition was evaluated by endoscopy and histology. Median transit time was 189 min (105–365. Median ejection fraction at defaecography (EF was 49% (3–77 and 62% (17–98 after first and second defecation. Median pouch volume was 223 mL (100–360. A median daily stool frequency of nine (4–25 was reported and three (14% patients suffered from daytime incontinence. No patients had symptomatic or endoscopic pouchitis; however, the histology showed unspecific inflammation in 19 (90% patients. There was no correlation between transit time, evacuation fraction (EF and pouch function in univariate analysis. However, we found a high body mass index (BMI and a low bowel movement frequency to be associated with a longer transit time by multivariate analysis. Scintigraphic determination of transit time and defaecography are feasible methods in patients with ileal pouch anal anastomosis, but the clinical relevance is yet doubtful.

  18. Effect of realistic and filtered stellar photometric noise on the detection of moons using photometric transit timing

    Directory of Open Access Journals (Sweden)

    Lewis K.

    2011-02-01

    Full Text Available The photometric transit timing technique was proposed by Szabó et al. (2006 as a method for discovering moons of transiting extrasolar planets. In the preliminary analysis of this technique, it was assumed that the noise in the transit lightcurve was well described by uncorrelated white noise. However, this assumption is not necessarily realistic. To determine the effect of using more realistic lightcurves, transit timing uncertainties are calculated for the case of white noise, measured solar photometric noise and measured solar photometric noise that has been filtered. It is found that for light curves contaminated with realistic photometric noise, the transit timing uncertainties are dramatically increased (and thus moon detection reduced. In addition, we find that while filtering reduced this problem, it did not negate it.

  19. The role of nuclear energy in times of energy transition

    International Nuclear Information System (INIS)

    2012-01-01

    Since the reactor catastrophe in Fukushima, the risk of nuclear power has once again become more evident to the public and has also led to a rethinking of politics in Europe. Slogans like ''Nuclear Power, No Thanks!'', ''Get Out of Euratom'' are making more and more the rounds. The phase-out of nuclear energy is the topic that is increasingly provoking people to think. But how should one handle this? What role will nuclear energy play in a distant future? Central factors such as the economic viability of renewable energy sources and the environmental and social compatibility of production and distribution must be taken into account, while at the same time the reduction of pollutants and greenhouse gases must continue. If this is done without nuclear energy, is the rapid abandonment of nuclear energy even necessary or does nuclear energy generation have to be used as a temporary solution? (roessner)

  20. TRANSIT

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...

  1. [Determination of total and segmental colonic transit time in constipated children].

    Science.gov (United States)

    Zhang, Shu-cheng; Wang, Wei-lin; Bai, Yu-zuo; Yuan, Zheng-wei; Wang, Wei

    2003-03-01

    To determine the total and segmental colonic transit time of normal Chinese children and to explore its value in constipation in children. The subjects involved in this study were divided into 2 groups. One group was control, which had 33 healthy children (21 males and 12 females) aged 2 - 13 years (mean 5 years). The other was constipation group, which had 25 patients (15 males and 10 females) aged 3 - 14 years (mean 7 years) with constipation according to Benninga's criteria. Written informed consent was obtained from the parents of each subject. In this study the simplified method of radio opaque markers was used to determine the total gastrointestinal transit time and segmental colonic transit time of the normal and constipated children, and in part of these patients X-ray defecography was also used. The total gastrointestinal transit time (TGITT), right colonic transit time (RCTT), left colonic transit time (LCTT) and rectosigmoid colonic transit time (RSTT) of the normal children were 28.7 +/- 7.7 h, 7.5 +/- 3.2 h, 6.5 +/- 3.8 h and 13.4 +/- 5.6 h, respectively. In the constipated children, the TGITT, LCTT and RSTT were significantly longer than those in controls (92.2 +/- 55.5 h vs 28.7 +/- 7.7 h, P < 0.001; 16.9 +/- 12.6 h vs 6.5 +/- 3.8 h, P < 0.01; 61.5 +/- 29.0 h vs 13.4 +/- 5.6 h, P < 0.001), while the RCTT had no significant difference. X-ray defecography demonstrated one rectocele, one perineal descent syndrome and one puborectal muscle syndrome, respectively. The TGITT, RCTT, LCTT and RSTT of the normal children were 28.7 +/- 7.7 h, 7.5 +/- 3.2 h, 6.5 +/- 3.8 h and 13.4 +/- 5.6 h, respectively. With the segmental colonic transit time, constipation can be divided into four types: slow-transit constipation, outlet obstruction, mixed type and normal transit constipation. X-ray defecography can demonstrate the anatomical or dynamic abnormalities within the anorectal area, with which constipation can be further divided into different subtypes, and

  2. Assessment of bolus transit with intraluminal impedance measurement in patients with esophageal motility disorders.

    Science.gov (United States)

    Bogte, A; Bredenoord, A J; Oors, J; Siersema, P D; Smout, A J P M

    2015-10-01

    The clinical management of patients with non-obstructive dysphagia is notoriously difficult. Esophageal impedance measurement can be used to measure esophageal bolus transit without the use of radiation exposure to patients. However, validation of measurement of bolus transit with impedance monitoring has only been performed in healthy subjects with normal motility and not in patients with dysphagia and esophageal motility disorders. The aim was, therefore, to investigate the relationship between transit of swallowed liquid boluses in healthy controls and in patients with dysphagia. Twenty healthy volunteers and 20 patients with dysphagia underwent concurrent impedance measurement and videofluoroscopy. Each subject swallowed five liquid barium boluses. The ability of detecting complete or incomplete bolus transit by means of impedance measurement was assessed, using radiographic bolus transit as the gold standard. Impedance monitoring recognized stasis and transit in 80.5% of the events correctly, with 83.9% of bolus transit being recognized and 77.2% of stasis being recognized correctly. In controls 79.8% of all swallows were scored correctly, whereas in patients 81.3% of all swallows were scored correctly. Depending on the contractility pattern, between 77.0% and 94.3% of the swallows were scored correctly. Impedance measurement can be used to assess bolus clearance patterns in healthy subjects, but can also be used to reliably assess bolus transit in patients with dysphagia and motility disorders. © 2015 John Wiley & Sons Ltd.

  3. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.; Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-12-31

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  4. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 [mu]s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  5. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States)); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  6. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States); Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-09-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  7. On the use of spring baseflow recession for a more accurate parameterization of aquifer transit time distribution functions

    Directory of Open Access Journals (Sweden)

    J. Farlin

    2013-05-01

    Full Text Available Baseflow recession analysis and groundwater dating have up to now developed as two distinct branches of hydrogeology and have been used to solve entirely different problems. We show that by combining two classical models, namely the Boussinesq equation describing spring baseflow recession, and the exponential piston-flow model used in groundwater dating studies, the parameters describing the transit time distribution of an aquifer can be in some cases estimated to a far more accurate degree than with the latter alone. Under the assumption that the aquifer basis is sub-horizontal, the mean transit time of water in the saturated zone can be estimated from spring baseflow recession. This provides an independent estimate of groundwater transit time that can refine those obtained from tritium measurements. The approach is illustrated in a case study predicting atrazine concentration trend in a series of springs draining the fractured-rock aquifer known as the Luxembourg Sandstone. A transport model calibrated on tritium measurements alone predicted different times to trend reversal following the nationwide ban on atrazine in 2005 with different rates of decrease. For some of the springs, the actual time of trend reversal and the rate of change agreed extremely well with the model calibrated using both tritium measurements and the recession of spring discharge during the dry season. The agreement between predicted and observed values was however poorer for the springs displaying the most gentle recessions, possibly indicating a stronger influence of continuous groundwater recharge during the summer months.

  8. Minimal cardiac transit-times in the diagnosis of heart disease. Measurements with the gamma-retina V and sup(113m)-In. The influence of long-term digitalization on central volume relations in patients with latent and manifest cardiac insufficiency

    Energy Technology Data Exchange (ETDEWEB)

    Freundlieb, C; Vyska, K; Hoeck, A; Schicha, H; Becker, V; Feinendegen, L E [Kernforschungsanlage Juelich G.m.b.H. (F.R. Germany). Inst. fuer Medizin

    1976-02-01

    Using Indium-113m and the Gamma Retina V (Fucks-Knipping Camera), the minimal cardiac transit times (MTTs) were measured radiocardiographically from the right auricle to the aortic root. This analysis served to determine the relation between stroke volume and the segment volume of the part of circulation between the right auricle and the aortic root. In 39 patients with myocardial insufficiency of different clinical degree the effectiveness of digitalization was, up to a period of 5 years, measured by means of the volume relation mentioned above. The following conclusions can be drawn from the results: digitalization of patients with myocardial insufficiency leads to an improvement of the impaired relation of central volumes. In patients with diminished cardiac reserve the improvement is drastic and often results in a nearly complete normalization. The data remain constant during therapy even for an observation period of 5 years. Digitalization of patients with congestive heart failure only leads to a partial improvement. In contrast to patients with diminished cardiac reserve this effect is temporary. The different behaviour of the relation between stroke volume and segment volume in patients with diminished cardiac reserve and congestive heart failure under prolonged administration of digitalis points to the necessity of treatment with digitalis in the early stage of myocardial disease.

  9. Firing patterns transition and desynchronization induced by time delay in neural networks

    Science.gov (United States)

    Huang, Shoufang; Zhang, Jiqian; Wang, Maosheng; Hu, Chin-Kun

    2018-06-01

    We used the Hindmarsh-Rose (HR) model (Hindmarsh and Rose, 1984) to study the effect of time delay on the transition of firing behaviors and desynchronization in neural networks. As time delay is increased, neural networks exhibit diversity of firing behaviors, including regular spiking or bursting and firing patterns transitions (FPTs). Meanwhile, the desynchronization of firing and unstable bursting with decreasing amplitude in neural system, are also increasingly enhanced with the increase of time delay. Furthermore, we also studied the effect of coupling strength and network randomness on these phenomena. Our results imply that time delays can induce transition and desynchronization of firing behaviors in neural networks. These findings provide new insight into the role of time delay in the firing activities of neural networks, and can help to better understand the firing phenomena in complex systems of neural networks. A possible mechanism in brain that can cause the increase of time delay is discussed.

  10. Daylight saving time transitions and hospital treatments due to accidents or manic episodes

    Directory of Open Access Journals (Sweden)

    Lönnqvist Jouko

    2008-02-01

    Full Text Available Abstract Background Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003. Methods The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003. Results The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes. Conclusion One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment.

  11. Daylight saving time transitions and hospital treatments due to accidents or manic episodes

    Science.gov (United States)

    Lahti, Tuuli A; Haukka, Jari; Lönnqvist, Jouko; Partonen, Timo

    2008-01-01

    Background Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003. Methods The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003. Results The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes. Conclusion One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment. PMID:18302734

  12. Anthropogenic CO2 in the oceans estimated using transit time distributions

    International Nuclear Information System (INIS)

    Waugh, D.W.; McNeil, B.I.

    2006-01-01

    The distribution of anthropogenic carbon (Cant) in the oceans is estimated using the transit time distribution (TTD) method applied to global measurements of chlorofluorocarbon-12 (CFC12). Unlike most other inference methods, the TTD method does not assume a single ventilation time and avoids the large uncertainty incurred by attempts to correct for the large natural carbon background in dissolved inorganic carbon measurements. The highest concentrations and deepest penetration of anthropogenic carbon are found in the North Atlantic and Southern Oceans. The estimated total inventory in 1994 is 134 Pg-C. To evaluate uncertainties the TTD method is applied to output from an ocean general circulation model (OGCM) and compared the results to the directly simulated Cant. Outside of the Southern Ocean the predicted Cant closely matches the directly simulated distribution, but in the Southern Ocean the TTD concentrations are biased high due to the assumption of 'constant disequilibrium'. The net result is a TTD overestimate of the global inventory by about 20%. Accounting for this bias and other centred uncertainties, an inventory range of 94-121 Pg-C is obtained. This agrees with the inventory of Sabine et al., who applied the DeltaC* method to the same data. There are, however, significant differences in the spatial distributions: The TTD estimates are smaller than DeltaC* in the upper ocean and larger at depth, consistent with biases expected in DeltaC* given its assumption of a single parcel ventilation time

  13. Critical Time Intervention for Homeless People Making the Transition to Community Living: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Vet, R. de; Beijersbergen, M.D.; Jonker, I.E.; Lako, D.A.M.; Hemert, A.M. van; Herman, D.B.; Wolf, J.R.L.M.

    2017-01-01

    To help create an evidence base in Europe for effective interventions that improve the well-being of homeless people, we tested whether critical time intervention (CTI), a time-limited intervention developed to support vulnerable people during times of transition, is effective outside the United

  14. On the fast estimation of transit times application to BWR simulated data

    International Nuclear Information System (INIS)

    Antonopoulos-Domis, M.; Marseguerra, M.; Padovani, E.

    1996-01-01

    Real time estimators of transit times are proposed. BWR noise is simulated including a global component due to rod vibration. The time obtained form the simulation is used to investigate the robustness and noise immunity of the estimators. It is found that, in presence of a coincident (global) signal, the cross-correlation function is the worst estimator. (authors)

  15. Gastrointestinal Transit Time, Glucose Homeostasis and Metabolic Health: Modulation by Dietary Fibers.

    Science.gov (United States)

    Müller, Mattea; Canfora, Emanuel E; Blaak, Ellen E

    2018-02-28

    Gastrointestinal transit time may be an important determinant of glucose homeostasis and metabolic health through effects on nutrient absorption and microbial composition, among other mechanisms. Modulation of gastrointestinal transit may be one of the mechanisms underlying the beneficial health effects of dietary fibers. These effects include improved glucose homeostasis and a reduced risk of developing metabolic diseases such as obesity and type 2 diabetes mellitus. In this review, we first discuss the regulation of gastric emptying rate, small intestinal transit and colonic transit as well as their relation to glucose homeostasis and metabolic health. Subsequently, we briefly address the reported health effects of different dietary fibers and discuss to what extent the fiber-induced health benefits may be mediated through modulation of gastrointestinal transit.

  16. Ultra Fast Timing Measurements at $^{78}$Ni and $^{132}$Sn

    CERN Multimedia

    2002-01-01

    We propose to measure level lifetimes in the exotic nuclei of $^{81}$Ga and $^{80}$Ga in the vicinity of $^{78}$Ni and of $^{135}$Sb and $^{134}$Sb above $^{132}$Sn by the time-delayed technique. These are relatively simple nuclear systems with a few particles and/or holes outside of the doubly-magic core thus can be treated rather precisely within the shell model. The anticipated new structure information on these nuclei, and in particular the lifetime results will put constraints on the model parameters and will serve to verify their predictions. The selected nuclei are some of the most exotic ones just above $^{78}$Ni or $^{132}$Sn, where the transition rates can be studied at present. Of the strongest interest is the nucleus of $^{81}$Ga, which has only 3 valence protons outside of $^{78}$Ni with the lowest proton orbits being $p_{3/2}$ and $f_{5/2}$. The Ml transition between these states, although allowed by the selection rules, should be $\\textit{l}$-forbidden thus very slow. This should give rise to a...

  17. Electric dipole transitions for four-times ionized cerium (Ce V)

    Energy Technology Data Exchange (ETDEWEB)

    Usta, Betül Karaçoban, E-mail: bkaracoban@sakarya.edu.tr; Akgün, Elif, E-mail: elif.akgun@ogr.sakarya.edu.tr; Alparslan, Büşra, E-mail: busra.alparslan1@ogr.sakarya.edu.tr [Physics Department, Sakarya University, 54187, Sakarya (Turkey)

    2016-03-25

    We have calculated the transition parameters, such as wavelengths, oscillator strengths, and transition probabilities (or rates), for the electric dipole (E1) transitions in four-times ionized cerium (Ce V, Z = 58) by using the multiconfiguration Hartree-Fock method within the framework of Breit-Pauli (MCHF+BP) relativistic corrections and the relativistic Hartree-Fock (HFR) method. The obtained results have been compared with other works available in literature. A discussion of these calculations for Ce V in this study has also been in view of the MCHF+BP and HFR methods.

  18. On entropy change measurements around first order phase transitions in caloric materials.

    Science.gov (United States)

    Caron, Luana; Ba Doan, Nguyen; Ranno, Laurent

    2017-02-22

    In this work we discuss the measurement protocols for indirect determination of the isothermal entropy change associated with first order phase transitions in caloric materials. The magneto-structural phase transitions giving rise to giant magnetocaloric effects in Cu-doped MnAs and FeRh are used as case studies to exemplify how badly designed protocols may affect isothermal measurements and lead to incorrect entropy change estimations. Isothermal measurement protocols which allow correct assessment of the entropy change around first order phase transitions in both direct and inverse cases are presented.

  19. Neutron depolarization measurements of HoCo2 near the magnetic phase transition

    International Nuclear Information System (INIS)

    Kraan, W.

    1976-09-01

    The magnetic phase transition in HoCo 2 at zero applied field is investigated. The Landau theory of magnetic phase transition is discussed. The experimental technique for neutron depolarization measurements in the temperature range 65-90 K is described

  20. Validity and reliability of the Palliative Care Transition Measure for Caregivers (PCTM-C).

    Science.gov (United States)

    D'Angelo, Daniela; Mastroianni, Chiara; Artico, Marco; Biagioli, Valentina; Latina, Roberto; Guarda, Michela; Piredda, Michela; De Marinis, Maria Grazia

    2018-01-21

    Patients suffering from advanced disease face different care transitions. The transition from acute to palliative care is challenging and may lead to the discontinuity of care. Family caregivers become important sources of information, as patients begin to experience difficulties in coping with emotional transition events. The Care Transition Measure was developed to evaluate care transitions as experienced by the elderly. It has never been used in palliative care. The aim of this study was to test the validity and reliability of a modified version of the Palliative Care Transition Measure, specifically the Palliative Care Transition Measure for Caregivers (PCTM-C). The study included two main phases. Phase I focused on the construction of a modified version of the Palliative Care Transition Measure through two focus groups and by computing the content validity index. Phase II focused on testing the psychometric properties of the PCTM-C on 272 family caregivers through confirmatory factor analysis. Result The content validity index for each of the items was higher than 0.80, whereas that for the scale was 0.95. The model tested with confirmatory factor analysis fitted the data well and confirmed that the transition measures referred to communication, integrated care and a trusting-relationship, and therefore the core dimensions of continuity according to existing conceptual models. The internal consistency was high (Cronbach's alpha = 0.94). Significance of results The PCTM-C proved to be a suitable measure of the quality of such transitions. It may be used in clinical practice as a continuity quality indicator and has the potential to guide interventions to enhance family caregivers' experience of care continuity.

  1. Using Forbush Decreases to Derive the Transit Time of ICMEs Propagating from 1 AU to Mars

    Science.gov (United States)

    Freiherr von Forstner, Johan L.; Guo, Jingnan; Wimmer-Schweingruber, Robert F.; Hassler, Donald M.; Temmer, Manuela; Dumbović, Mateja; Jian, Lan K.; Appel, Jan K.; Čalogović, Jaša.; Ehresmann, Bent; Heber, Bernd; Lohf, Henning; Posner, Arik; Steigies, Christian T.; Vršnak, Bojan; Zeitlin, Cary J.

    2018-01-01

    The propagation of 15 interplanetary coronal mass ejections (ICMEs) from Earth's orbit (1 AU) to Mars (˜1.5 AU) has been studied with their propagation speed estimated from both measurements and simulations. The enhancement of magnetic fields related to ICMEs and their shock fronts causes the so-called Forbush decrease, which can be detected as a reduction of galactic cosmic rays measured on ground. We have used galactic cosmic ray (GCR) data from in situ measurements at Earth, from both STEREO A and STEREO B as well as GCR measurements by the Radiation Assessment Detector (RAD) instrument on board Mars Science Laboratory on the surface of Mars. A set of ICME events has been selected during the periods when Earth (or STEREO A or STEREO B) and Mars locations were nearly aligned on the same side of the Sun in the ecliptic plane (so-called opposition phase). Such lineups allow us to estimate the ICMEs' transit times between 1 and 1.5 AU by estimating the delay time of the corresponding Forbush decreases measured at each location. We investigate the evolution of their propagation speeds before and after passing Earth's orbit and find that the deceleration of ICMEs due to their interaction with the ambient solar wind may continue beyond 1 AU. We also find a substantial variance of the speed evolution among different events revealing the dynamic and diverse nature of eruptive solar events. Furthermore, the results are compared to simulation data obtained from two CME propagation models, namely the Drag-Based Model and ENLIL plus cone model.

  2. Thermophysical Property Measurements of Silicon-Transition Metal Alloys

    Science.gov (United States)

    Banish, R. Michael; Erwin, William R.; Sansoucie, Michael P.; Lee, Jonghyun; Gave, Matthew A.

    2014-01-01

    Metals and metallic alloys often have high melting temperatures and highly reactive liquids. Processing reactive liquids in containers can result in significant contamination and limited undercooling. This is particularly true for molten silicon and it alloys. Silicon is commonly termed "the universal solvent". The viscosity, surface tension, and density of several silicon-transition metal alloys were determined using the Electrostatic Levitator system at the Marshall Space Flight Center. The temperature dependence of the viscosity followed an Arrhenius dependence, and the surface tension followed a linear temperature dependence. The density of the melts, including the undercooled region, showed a linear behavior as well. Viscosity and surface tension values were obtain for several of the alloys in the undercooled region.

  3. Usage of the micropixel detector TimePix for observation of the dynamics of phase transitions in metals

    Directory of Open Access Journals (Sweden)

    M. V. Pugach

    2012-12-01

    Full Text Available The results for the test of a TimePix hybrid detector as a tool for measuring and imaging in real time dynamics of phase transitions in metal alloys under heating or cooling are presented. The X-rays ( ~ 10 keV experimental setup explored for the diffraction studies at the Institute for Problems of Material Science NASU (Kyiv is briefly described. An evolution of the diffraction maxima position (~ 20 μm accuracy of the scattered X-rays was ob-served with exposures from a few dozen to a few hundred milliseconds under heating or cooling of the samples of Armco iron at a rate of 100 to 250 C/s. Data for the phase transitions (alpha-, gamma-phases observed during heating/cooling (20 - 1250 °C using the X-ray diffraction were measured.

  4. Determination of Gastrointestinal Transit Times in Barred Owls ( Strix varia ) by Contrast Fluoroscopy.

    Science.gov (United States)

    Doss, Grayson A; Williams, Jackie M; Mans, Christoph

    2017-06-01

    Contrast imaging studies are routinely performed in avian patients when an underlying abnormality of the gastrointestinal (GI) tract is suspected. Fluoroscopy offers several advantages over traditional radiography and can be performed in conscious animals with minimal stress and restraint. Although birds of prey are commonly encountered as patients, little is known about GI transit times and contrast imaging studies in these species, especially owls. Owls are commonly encountered in zoological, educational, and wildlife settings. In this study, 12 adult barred owls ( Strix varia ) were gavage fed a 30% weight-by-volume barium suspension (25 mL/kg body weight). Fluoroscopic exposures were recorded at 5, 15, 30, 60, 120, 180, 240, and 300 minutes after administration. Overall GI transit time and transit times of various GI organs were recorded. Median (interquartile range [IQR]) overall GI transit time was 60 minutes (IQR: 19-60 minutes) and ranged from 5-120 minutes. Ventricular and small intestinal contrast filling was rapid. Ventricular emptying was complete by a median of 60 minutes (IQR: 30-120 minutes; range: 30-240 minutes), whereas small intestinal emptying was not complete in 9/12 birds by 300 minutes. Median small intestinal contraction rate was 15 per minute (IQR: 13-16 minutes; range: 10-19 minutes). Median overall GI transit time in barred owls is more rapid than mean transit times reported for psittacine birds and red-tailed hawks ( Buteo jamaicensis ). Fluoroscopy is a safe, suitable method for investigating GI motility and transit in this species.

  5. The determination of allowed outage time using the evaluation of transition risk

    International Nuclear Information System (INIS)

    Kang, D. I.; Kim, K. Y.; Jang, S. C.

    2001-03-01

    he objectives of this study are to propose a new evaluation method for transition risk and to determine the AOT using the new method. We review and compare the evaluation methods of transition risk which was previously studied. We also identify important assumptions used in previous studies for the evaluation of transition risk. We select general items required for the development of evaluation method for the transition risk. Based on the items selected, we propose a new evaluation method for transition risk. The new evaluation method for the transition risk is based on following assumptions; 1)For the same time span, the risk occurred from the failure to the completion of component repair during power operation is the same as the total risk including the risk occurred from power operation to specific shutdown/low power operation and the risk from specific shutdown/low power operation to power operation. 2)Shutdown operation and the repair of components are initiated just after the identification of the failure of components. The evaluation of the transition risk is performed to incorporate the characteristics of shutdown operation into Ulchin Units 3 and 4 Level 1 internal PSA for power operation. The application results of the new method to the HPSIS and the LPSIS for Ulchin Units 3 and 4 show that the AOT of HPSIS is properly determined and the AOT of LPSIS can be greatly increased. In this study, the main factors affecting the determination of AOT using the evaluation for transition risk are identified as the time of shutdown operation, the consideration of the change on common cause failure probability, and the risk of shutdown operation. It is expected that the evaluation method for the transition risk proposed in this study will be used for the determination of AOT and for the decision, in the case of the components unavailable, whether power operation is continuously performed or shutdown operation is initiated

  6. Reactive scattering theory for molecular transitions in time-dependent fields

    International Nuclear Information System (INIS)

    Peskin, U.; Miller, W.H.

    1995-01-01

    A new approach is introduced for computing probabilities of molecular transitions in time-dependent fields. The method is based on the stationary (t,t') representation of the Schroedinger equation and is shown to be equivalent to infinite order time-dependent perturbation theory. Bound-to-bound (i.e., photoexcitation) and bound-to-continuum (i.e., photoreaction) transitions are regarded as reactive collisions with the ''time coordinate'' as the reaction coordinate in an extended Hilbert space. A numerical method based on imposing absorbing boundary conditions for the time coordinate in a discrete variable representation framework is introduced. A single operation of the Green's operator provides all the state-specific transition probabilities as well as partial state-resolved (inclusive) reaction probabilities. Illustrative numerical applications are given for model systems

  7. The Ebb and Flow of Filipino First-Time Fatherhood Transition Space: A Grounded Theory Study.

    Science.gov (United States)

    Villamor, Neil Jupiter E; de Guzman, Allan B; Matienzo, Evangeline T

    2016-11-01

    Fatherhood, as a developmental process, is both a human experience and a text that needs to be read. For developing nations like the Philippines, little is known about the process undergone by first-time fathers on their transition to fatherhood, and how nurses can play a significant role in assisting them. This grounded theory study purported to conceptualize the multifaceted process of transition from the lens of Filipino first-time fathers' lived experiences. A total of 20 first-time fathers from Metro Manila, Philippines, were purposively selected to take part in an individual, semistructured, and in-depth interview. The Glaserian (classical) method of analysis was specifically used, and field texts were inductively analyzed using a repertory grid. Member checking and correspondence were done to validate the findings of the study. Six surfacing stages emerged relative to the process of transition. Interestingly, The B.R.I.D.G.E. Theory of First-Time Fatherhood Transition Space describes how these fathers progress from the beholding, reorganizing, inhibiting, delivering, grasping, and embracing phases toward successful transition. This emerged theoretical model can be used in framing health care programs where the needs of fathers during this period are met and addressed. Finally, it can also be used in guiding nurses in their provision of a more empathetic care for first-time fathers. © The Author(s) 2015.

  8. Xylanase, protease and superdosing phytase interactions in broiler performance, carcass yield and digesta transit time

    Directory of Open Access Journals (Sweden)

    Tiago T. dos Santos

    2017-06-01

    Full Text Available The interaction of xylanase, protease and superdosing (1,500 FTU/kg phytase in a 2 × 2 × 2 factorial arrangement was studied in broilers fed sorghum-based diets. A total of 2,800 one-day-old unsexed Ross 308 chicks were housed in 56 pens with 50 birds per pen, with or without inclusion of xylanase, protease and phytase, totaling 8 treatments and 7 replicates per treatment. Body weight (BW and feed intake (FI were measured at 21 and 42 days of age, and mortality corrected feed conversion ratio (FCR was calculated for each period and cumulatively. Tibia ash and carcass yield were determined in 2 birds per replicate at 21 and 42 days of age, respectively. Digesta transit time was determined at 21, 28, 35 and 42 days of age using 5 birds per replicate. Results showed that superdosing phytase increased BW and FI at 42 days of age (P < 0.05 and xylanase improved FCR (P < 0.05. Xylanase and phytase also positively influenced carcass yield and breast weight, respectively. Overall, inclusion of superdosing phytase increased transit time when included in a diet containing xylanase, and no change with protease inclusion. In conclusion, the beneficial effects of xylanase, protease and superdosing phytase in broiler performance were not additive. This limitation is likely not related to the lack of efficacy of any one of the individual enzymes but to a limitation of the bird to respond additively to successive additions of enzymes.

  9. Relationships between transit time in man and in vitro fermentation of dietary fiber by fecal bacteria.

    Science.gov (United States)

    Oufir, L E; Barry, J L; Flourié, B; Cherbut, C; Cloarec, D; Bornet, F; Galmiche, J P

    2000-08-01

    To assess the effects of drug-induced changes in mean transit time (MTT) on the activity of human fecal flora in vitro. The activity of fecal flora was estimated by the ability of a fecal inoculum to ferment a substrate (beet fiber) in vitro in a batch system for 24 h. The inoculum was collected from 8 healthy volunteers studied during three 3-week randomized periods, who received a controlled diet alone (control period) or the same diet with either cisapride or loperamide. Cisapride and loperamide were adjusted in order to halve and double MTT measured during the control period. At the end of each period, the percentage disappearance of the initial added substrate and the concentration and the profile of short-chain fatty acids (SCFAs), were determined. In the control period, the pH of the inoculum and SCFA concentration were inversely related to MTT (P=0.0001). Individual SCFA production was also significantly related to MTT (P<0.01). Cisapride-reduced transit time was associated with a significant rise in the concentrations of total SCFAs (P<0.05), propionic and butyric acids (P<0.05) and the percentage substrate disappearance (P<0.05). Inverse relations were observed during the loperamide period. Moreover, MTT was inversely related to the percentage substrate disappearance (P<0.001), SCFA production (P<0.001) and butyrate production (P<0.0005). Changes in MTT alter bacterial activity and modify the bacterial pathways affecting the proportion of individual SCFAs. European Journal of Clinical Nutrition (2000) 54, 603-609

  10. Mobilising female labour market reserves: What promotes women’s transitions from part-time to full-time work?

    OpenAIRE

    Kitterød, Ragni Hege; Rønsen, Marit; Seierstad, Ane

    2011-01-01

    Considering the high female part-time rates in Norway, one may envisage a sizeable additional labour supply if more part-time working women would switch to full time. In view of an ageing population and increased demand for labour in the future, we investigate this issue by studying married and cohabiting women’s transitions from part-time to full-time work based on panel data from 2003-2009. Contrary to evidence from other countries with well-established support for working mo...

  11. Long Spin-Relaxation Times in a Transition-Metal Atom in Direct Contact to a Metal Substrate.

    Science.gov (United States)

    Hermenau, Jan; Ternes, Markus; Steinbrecher, Manuel; Wiesendanger, Roland; Wiebe, Jens

    2018-03-14

    Long spin-relaxation times are a prerequisite for the use of spins in data storage or nanospintronics technologies. An atomic-scale solid-state realization of such a system is the spin of a transition-metal atom adsorbed on a suitable substrate. For the case of a metallic substrate, which enables the direct addressing of the spin by conduction electrons, the experimentally measured lifetimes reported to date are on the order of only hundreds of femtoseconds. Here, we show that the spin states of iron atoms adsorbed directly on a conductive platinum substrate have a surprisingly long spin-relaxation time in the nanosecond regime, which is comparable to that of a transition metal atom decoupled from the substrate electrons by a thin decoupling layer. The combination of long spin-relaxation times and strong coupling to conduction electrons implies the possibility to use flexible coupling schemes to process the spin information.

  12. Association of rumination time with subclinical ketosis in transition dairy cows.

    Science.gov (United States)

    Kaufman, E I; LeBlanc, S J; McBride, B W; Duffield, T F; DeVries, T J

    2016-07-01

    The objective of this study was to characterize the relationship between rumination and subclinical ketosis (SCK) in transition dairy cows. A study was conducted on 4 commercial dairy farms in eastern Ontario, Canada. A total of 339 Holstein dairy cows (107 primiparous and 232 multiparous) were monitored for rumination activity and SCK from 14 d before calving until 28 d after calving. Rumination was recorded daily using an automated monitoring system. A blood sample was taken from the coccygeal vein of each cow for measurement of β-hydroxybutyrate (BHB) once weekly throughout the 6-wk observation period. Cows with BHB ≥1.2mmol/L in any of the 4 postpartum samples were considered to have SCK. Cases of retained placenta, metritis, milk fever, or mastitis during the study period were also recorded. Cows were categorized into 1 of 4 groups: healthy cows (HLT) that had no SCK or any other recorded health problem (n=139); cows treated for at least one health issue other than SCK (HLT+; n=50); cows with SCK (hyperketonemia; HYK) with no other health problems during transition (n=97); or cows (HYK+) that had SCK and one or more other health problems (n=53). Daily rumination time was summarized by week and comparisons were made between HLT and HYK and HYK+. From 2 wk before calving (wk -2) to 4 wk after calving (wk +4), there was no difference in rumination time (409±9.8min/d) among HLT, HYK, and HYK+ cows in their first lactation. Multiparous cows in HLT spent an average of 459±11.3min/d ruminating from wk -2 to wk +4. Multiparous HYK cows ruminated 25±12.8min/d less than HLT cows, whereas HYK+ cows ruminated 44±15.6min/d less than HLT cows. The largest differences in rumination time between HLT and HYK+ cows were seen during wk -1, +1, and +2, when HYK+ cows ruminated 48±17.2, 73±16.0, and 65±19.4min/d less than HLT cows, respectively. In multiparous cows, increased odds of HYK were associated with greater milk yield in the previous lactation, greater loss of

  13. Progress on precision measurements of inner shell transitions in highly charged ions at an ECR ion source

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, Csilla I.; Indelicato, Paul; LeBigot, Eric-Olivier; Vallette, Alexandre; Amaro, Pedro; Guerra, Mauro; Gumberidze, Alex [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France); Centro de Fisica Atomica, CFA, Departamento de Fisica (Portugal); Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France)

    2012-05-25

    Inner shell transitions of highly charged ions produced in the plasma of an Electron Cyclotron Resonance Ion Source (ECRIS) were observed the first time by a Double Crystal Spectrometer (DCS). The DCS is a well-used tool in precision x-ray spectroscopy due to its ability of precision wavelength measurement traced back to a relative angle measurement. Because of its requirement for a bright x-ray source the DCS has not been used before in direct measurements of highly charged ions (HCI). Our new precision measurement of inner shell transitions in HCI is not just going to provide new x-ray standards for quantum metrology but can also give information about the plasma in which the ions reside. Ionic temperatures and with that the electron density can be determined by thorough examination of line widths measured with great accuracy.

  14. Magnet tracking allows assessment of regional gastrointestinal transit times in children.

    Science.gov (United States)

    Hedsund, Caroline; Joensson, Iben Moeller; Gregersen, Tine; Fynne, Lotte; Schlageter, Vincent; Krogh, Klaus

    2013-01-01

    Data on small intestinal transit time in healthy children are lacking, and normal values for gastric emptying and colonic transit time are sparse. Conventional methods, including radiopaque markers, scintigraphy, and PillCam™ involve radiation or require the child to swallow a large pill. The minimally invasive, radiation-free Motility Tracking System-1 (MTS-1) has been introduced for description of gastrointestinal motility in adults. The aim of the study was to evaluate the MTS-1 for assessment of gastrointestinal transit times and motility patterns in healthy children. Twenty-one healthy children (nine girls), median age 10 (range 7-12) years were included. For evaluation with MTS-1, a small magnetic pill was ingested and tracked through the gastrointestinal tract by a matrix of 16 magnetic sensors placed behind a nonmagnetic bed. The children were investigated for 8 hours after swallowing the magnetic pill and again for 4 hours the following morning. After leaving the unit, each child came back after every bowel movement to determine if the pill had been expelled. Nineteen children could swallow the pill. Characteristic contraction patterns were identified for the stomach (three per minute), small intestine (9-11 per minute), and colon (4-5 per minute). Median total gastrointestinal transit time was 37.7 (range 9.5-95.8) hours, median gastric emptying time was 37 (range 2-142) minutes, median small intestinal transit time was 302 (range 164 to >454) minutes, and median colorectal transit time was 38.1 (range 5.6-90.0) hours. MTS-1 allows minimally invasive evaluation of gastrointestinal motility in children. Use of the method is, however, restricted by the nonambulatory setup.

  15. Scintigraphic small intestinal transit time and defaecography in patients with J-pouch

    DEFF Research Database (Denmark)

    Kjær, Mie Dilling; Simonsen, Jane Angel; Hvidsten, Svend

    2015-01-01

    Objective methods for examination of pouch function are warranted for a better understanding of the functional result and treatment of dysfunction. The objective of this study was to evaluate the results of scintigraphic intestinal transit time and defaecography compared to the results of pouch...... function, mucosal condition and a questionnaire on quality of life (QoL). This cross-sectional study included 21 patients. Scintigraphic transit time and defaecography was determined with the use of Tc-99m. Pouch function was assessed by number of bowel movements, pouch volume, and continence. Pouch...... mucosal condition was evaluated by endoscopy and histology. Median transit time was 189 min (105–365). Median ejection fraction at defaecography (EF) was 49% (3–77) and 62% (17–98) after first and second defecation. Median pouch volume was 223 mL (100–360). A median daily stool frequency of nine (4...

  16. Theoretical determination of transit time locus curves for ultrasonic pulse echo testing - ALOK. Pt. 4

    International Nuclear Information System (INIS)

    Grohs, B.

    1983-01-01

    The ALOK-technique allows the simultaneous detection of flaws and their evaluation with respect to type, location and dimension by interpretation of the transit time behaviour during scanning of the reflector. The accuracy of information obtained by means of this technique can be further improved both during interference elimination and reconstruction owing to the ability of exact calculation of possible transit time locus curves of given reflectors. The mathematical solution of transit time locus curve calculations refers here to pulse echo testing in consideration of the refraction of sound on the forward wedge/test object - interface. The method of solving the problem is equivalent to the Fermat's principle in optics. (orig.) [de

  17. The Transit-Time Distribution from the Northern Hemisphere Midlatitude Surface

    Science.gov (United States)

    Orbe, Clara; Waugh, Darryn W.; Newman, Paul A.; Strahan, Susan; Steenrod, Stephen

    2015-01-01

    The distribution of transit times from the Northern Hemisphere (NH) midlatitude surface is a fundamental property of tropospheric transport. Here we present an analysis of the transit time distribution (TTD) since air last contacted the northern midlatitude surface layer, as simulated by the NASA Global Modeling Initiative Chemistry Transport Model. We find that throughout the troposphere the TTD is characterized by long flat tails that reflect the recirculation of old air from the Southern Hemisphere and results in mean ages that are significantly larger than the modal age. Key aspects of the TTD -- its mode, mean and spectral width -- are interpreted in terms of tropospheric dynamics, including seasonal shifts in the location and strength of tropical convection and variations in quasi-isentropic transport out of the northern midlatitude surface layer. Our results indicate that current diagnostics of tropospheric transport are insufficient for comparing model transport and that the full distribution of transit times is a more appropriate constraint.

  18. Physical activity during video capsule endoscopy correlates with shorter bowel transit time.

    Science.gov (United States)

    Stanich, Peter P; Peck, Joshua; Murphy, Christopher; Porter, Kyle M; Meyer, Marty M

    2017-09-01

     Video capsule endoscopy (VCE) is limited by reliance on bowel motility for propulsion, and lack of physical activity has been proposed as a cause of incomplete studies. Our aim was to prospectively investigate the association between physical activity and VCE bowel transit.  Ambulatory outpatients receiving VCE were eligible for the study. A pedometer was attached at the time of VCE ingestion and step count was recorded at the end of the procedure. VCE completion was assessed by logistic regression models, which included step count (500 steps as one unit). Total transit time was analyzed by Cox proportional hazards models. The hazard ratios (HR) with 95 % confidence interval (CI) indicated the "hazard" of completion, such that HRs > 1 indicated a reduced transit time.  A total of 100 patients were included. VCE was completed in 93 patients (93 %). The median step count was 2782 steps. Step count was not significantly associated with VCE completion (odds ratio 1.45, 95 %CI 0.84, 2.49). Pedometer step count was significantly associated with shorter total, gastric, and small-bowel transit times (HR 1.09, 95 %CI 1.03, 1.16; HR 1.05, 95 %CI 1.00, 1.11; HR 1.07, 95 %CI 1.01, 1.14, respectively). Higher body mass index (BMI) was significantly associated with VCE completion (HR 1.87, 95 %CI 1.18, 2.97) and shorter bowel transit times (HR 1.05, 95 %CI 1.02, 1.08).  Increased physical activity during outpatient VCE was associated with shorter bowel transit times but not with study completion. In addition, BMI was a previously unreported clinical characteristic associated with VCE completion and should be included as a variable of interest in future studies.

  19. Quantum to Classical Transitions via Weak Measurements and Post-Selection

    Science.gov (United States)

    Cohen, Eliahu; Aharonov, Yakir

    Alongside its immense empirical success, the quantum mechanical account of physical systems imposes a myriad of divergences from our thoroughly ingrained classical ways of thinking. These divergences, while striking, would have been acceptable if only a continuous transition to the classical domain was at hand. Strangely, this is not quite the case. The difficulties involved in reconciling the quantum with the classical have given rise to different interpretations, each with its own shortcomings. Traditionally, the two domains are sewed together by invoking an ad hoc theory of measurement, which has been incorporated in the axiomatic foundations of quantum theory. This work will incorporate a few related tools for addressing the above conceptual difficulties: deterministic operators, weak measurements, and post-selection. Weak Measurement, based on a very weak von Neumann coupling, is a unique kind of quantum measurement with numerous theoretical and practical applications. In contrast to other measurement techniques, it allows to gather a small amount of information regarding the quantum system, with only a negligible probability of collapsing it onto an eigenstate of the measured observable. A single weak measurement yieldsan almost random outcome, but when performed repeatedly over a large ensemble, the averaged outcome becomes increasingly robust and accurate. Importantly, a long sequence of weak measurements can be thought of as a single projective measurement. We claim in this work that classical variables appearing in the o-world, such as center of mass, moment of inertia, pressure, and average forces, result from a multitude of quantum weak measurements performed in the micro-world. Here again, the quantum outcomes are highly uncertain, but the law of large numbers obliges their convergence to the definite quantities we know from our everyday lives. By augmenting this description with a final boundary condition and employing the notion of "classical

  20. Pulmonary blood volume and transit time in cirrhosis: relation to lung function

    DEFF Research Database (Denmark)

    Møller, Søren; Burchardt, H; Øgard, CG

    2006-01-01

    BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis......, in the controls, Pvolume...

  1. Time versus frequency domain measurements: layered model ...

    African Journals Online (AJOL)

    ... their high frequency content while among TEM data sets with low frequency content, the averaging times for the FEM ellipticity were shorter than the TEM quality. Keywords: ellipticity, frequency domain, frequency electromagnetic method, model parameter, orientation error, time domain, transient electromagnetic method

  2. Lifetime measurements in shape transition nucleus 188Pt

    Science.gov (United States)

    Rohilla, Aman; Gupta, C. K.; Singh, R. P.; Muralithar, S.; Chakraborty, S.; Sharma, H. P.; Kumar, A.; Govil, I. M.; Biswas, D. C.; Chamoli, S. K.

    2017-04-01

    Nuclear level lifetimes of high spin states in yrast and non-yrast bands of 188Pt nucleus have been measured using recoil distance plunger setup present at IUAC, Delhi. In the experiment nuclear states of interest were populated via 174Yb(18O,4 n)188Pt reaction at a beam energy of 79MeV provided by 15 UD Pelletron accelerator. The extracted B(E2\\downarrow) values show an initial rise up to 4+ state and then a nearly constant behavior with spin along yrast band, indicating change of nuclear structure in 188Pt at low spins. The good agreement between experimental and TPSM model B(E2\\downarrow) values up to 4^+ state suggests an increase in axial deformation of the nucleus. The average absolute β2 = 0.20 (3) obtained from measured B(E2\\downarrow) values matches well the values predicted by CHFB and IBM calculations for oblate ( β2 ˜ -0.19) and prolate (β2 ˜ 0.22) shapes. As the lifetime measurements do not yield the sign of β2, no definite conclusion can be drawn on the prolate or oblate collectivity of 188Pt on the basis of present measurements.

  3. Lifetime measurements in shape transition nucleus {sup 188}Pt

    Energy Technology Data Exchange (ETDEWEB)

    Rohilla, Aman; Gupta, C.K.; Chamoli, S.K. [University of Delhi, Department of Physics and Astrophysics, New Delhi (India); Singh, R.P.; Muralithar, S. [Inter University Accelerator Centre, New Delhi (India); Chakraborty, S.; Sharma, H.P. [Banaras Hindu University, Department of Physics, Varanasi (India); Kumar, A.; Govil, I.M. [Panjab University, Department of Physics, Chandigarh (India); Biswas, D.C. [Bhabha Atomic Research Center, Nuclear Physics Division, Trombay, Mumbai (India)

    2017-04-15

    Nuclear level lifetimes of high spin states in yrast and non-yrast bands of {sup 188}Pt nucleus have been measured using recoil distance plunger setup present at IUAC, Delhi. In the experiment nuclear states of interest were populated via {sup 174}Yb({sup 18}O,4n){sup 188}Pt reaction at a beam energy of 79MeV provided by 15 UD Pelletron accelerator. The extracted B(E2 ↓) values show an initial rise up to 4{sup +} state and then a nearly constant behavior with spin along yrast band, indicating change of nuclear structure in {sup 188}Pt at low spins. The good agreement between experimental and TPSM model B(E2 ↓) values up to 4{sup +} state suggests an increase in axial deformation of the nucleus. The average absolute β{sub 2} = 0.20 (3) obtained from measured B(E2 ↓) values matches well the values predicted by CHFB and IBM calculations for oblate (β{sub 2} ∝ -0.19) and prolate (β{sub 2} ∝ 0.22) shapes. As the lifetime measurements do not yield the sign of β{sub 2}, no definite conclusion can be drawn on the prolate or oblate collectivity of {sup 188}Pt on the basis of present measurements. (orig.)

  4. Latent Transition Analysis with a Mixture Item Response Theory Measurement Model

    Science.gov (United States)

    Cho, Sun-Joo; Cohen, Allan S.; Kim, Seock-Ho; Bottge, Brian

    2010-01-01

    A latent transition analysis (LTA) model was described with a mixture Rasch model (MRM) as the measurement model. Unlike the LTA, which was developed with a latent class measurement model, the LTA-MRM permits within-class variability on the latent variable, making it more useful for measuring treatment effects within latent classes. A simulation…

  5. Squid measurement of the Verwey transition on epitaxial (1 0 0) magnetite thin films

    International Nuclear Information System (INIS)

    Dediu, V.; Arisi, E.; Bergenti, I.; Riminucci, A.; Solzi, M.; Pernechele, C.; Natali, M.

    2007-01-01

    We report results on epitaxial magnetite (Fe 3 O 4 ) thin films grown by electron beam ablation on (1 0 0) MgAl 2 O 4 substrates. At 120 K magnetite undergoes a structural and electronic transition, the so-called Verwey transition, at which magnetic and conducting properties of the material change. We observed the Verwey transition on epitaxial films with a thickness of 50 nm by comparing zero-field cooling (ZFC) and field cooling (FC) curves measured with a superconducting quantum interference device (SQUID) magnetometer. Observation of the Verwey transition by SQUID measurements in the films is sign of their high crystalline quality. Room temperature ferromagnetism has also been found by magneto-optical Kerr rotation (MOKE) and confirmed by SQUID measurements, with a hysteresis loop showing a coercive field of hundreds of Oe

  6. Minimal cardiac transit-times in the diagnosis of heart disease

    International Nuclear Information System (INIS)

    Freundlieb, C.; Vyska, K.; Hoeck, A.; Schicha, H.; Becker, V.; Feinendegen, L.E.

    1976-01-01

    Using Indium-113m and the Gamma Retina V (Fucks-Knipping Camera), the minimal cardiac transit times (MTTs) were measured radiocardiographically from the right auricle to the aortic root. This analysis served to determine the relation between stroke volume and the segment volume of the part of circulation between the right auricle and the aortic root. In 39 patients with myocardial insufficiency of different clinical degree the effectiveness of digitalization was, up to a period of 5 years, measured by means of the volume relation mentioned above. The following conclusions can be drawn from the results: digitalization of patients with myocardial insufficiency leads to an improvement of the impaired relation of central volumes. In patients with diminished cardiac reserve the improvement is drastic and often results in a nearly complete normalization. The data remain constant during therapy even for an observation period of 5 years. Digitalization of patients with congestive heart failure only leads to a partial improvement. In contrast to patients with diminished cardiac reserve this effect is temporary. The different behaviour of the relation between stroke volume and segment volume in patients with diminished cardiac reserve and congestive heart failure under prolonged administration of digitalis points to the necessity of treatment with digitalis in the early stage of myocardial disease. (orig.) [de

  7. VizieR Online Data Catalog: Kepler-80 transit timing observations (MacDonald+, 2016)

    Science.gov (United States)

    MacDonald, M. G.; Ragozzine, D.; Fabrycky, D. C.; Ford, E. B.; Holman, M. J.; Isaacson, H. T.; Lissauer, J. J.; Lopez, E. D.; Mazeh, T.; Rogers, L.; Rowe, J. F.; Steffen, J. H.; Torres, G.

    2017-05-01

    Kepler-80 was observed photometrically by the Kepler Space Telescope. We had access to several sets of Transit Timing (TT) measurements, including the publicly available data from Rowe & Thompson (arXiv:1504.00707) and Mazeh et al. 2013 (Cat. J/ApJS/208/16). We also had the updated long-cadence TT estimates from the Mazeh group (Holczer et al. 2016, Cat. J/ApJS/225/9) and short-cadence TT data from both co-authors JR and DF. These were all measured using similar methods (see Mazeh et al. 2013, Cat. J/ApJS/208/16) and had no major differences. Spectra were taken of Kepler-80 by Keck and McDonald Observatories, and these spectra and preliminary interpretations are available on the Kepler Community Follow-up Observing Program (CFOP) website (https://cfop.ipac.caltech.edu). We acquired an 1800s high-resolution spectrum with the Keck I telescope and the High Resolution Echelle Spectrometer (HIRES) on 2011 July 20. The standard California Planet Search setup and data reduction of HIRES was used, resulting in a S/N of 35 at 5500Å. The C2 decker, with dimensions of 0.87''*14'', was used to allow a resolution of ~60000 and sky subtraction. (5 data files).

  8. Unconventional Topological Phase Transition in Two-Dimensional Systems with Space-Time Inversion Symmetry

    Science.gov (United States)

    Ahn, Junyeong; Yang, Bohm-Jung

    2017-04-01

    We study a topological phase transition between a normal insulator and a quantum spin Hall insulator in two-dimensional (2D) systems with time-reversal and twofold rotation symmetries. Contrary to the case of ordinary time-reversal invariant systems, where a direct transition between two insulators is generally predicted, we find that the topological phase transition in systems with an additional twofold rotation symmetry is mediated by an emergent stable 2D Weyl semimetal phase between two insulators. Here the central role is played by the so-called space-time inversion symmetry, the combination of time-reversal and twofold rotation symmetries, which guarantees the quantization of the Berry phase around a 2D Weyl point even in the presence of strong spin-orbit coupling. Pair creation and pair annihilation of Weyl points accompanying partner exchange between different pairs induces a jump of a 2D Z2 topological invariant leading to a topological phase transition. According to our theory, the topological phase transition in HgTe /CdTe quantum well structure is mediated by a stable 2D Weyl semimetal phase because the quantum well, lacking inversion symmetry intrinsically, has twofold rotation about the growth direction. Namely, the HgTe /CdTe quantum well can show 2D Weyl semimetallic behavior within a small but finite interval in the thickness of HgTe layers between a normal insulator and a quantum spin Hall insulator. We also propose that few-layer black phosphorus under perpendicular electric field is another candidate system to observe the unconventional topological phase transition mechanism accompanied by the emerging 2D Weyl semimetal phase protected by space-time inversion symmetry.

  9. Transit Time Flowmetry in Coronary Surgery-An Important Tool in Graft Verification

    Directory of Open Access Journals (Sweden)

    Emir Mujanović

    2007-08-01

    Full Text Available The aim of this study was to analyze the Transit time flow measurement (TTFM experience in the first 1000 CABG operations. First 1000 patients had coronary artery bypass grafting (CABG performed in Cardiovascular Clinic, University Clinical Centre Tuzla, Bosnia and Herzegovina, between September, 1998 and September, 2003. CABG without use of cardio-pulmonary bypass (CPB-(OPCAB was used as the preferential surgical method both because this method is reported to have equal or better results than CABG with use of CPB (ONCAB, and because of the significant cost savings realized. TTFM was routinely used in all grafts as a quality assurance measure. Criteria for a poor functioning graft were: low mean flow (MF, pul-satility index (PI above 5 and a poor diastolic flow pattern. When no reversible cause of poor TTFM results were identified the graft was revised. A total of 1394 grafts in OPCAB group and 1478 in ONCAB group were performed. A total of 38 grafts (2,72% in 37 patients (7,07% were revised in OPCAB group, and 26 grafts (1,75% in 26 patients (5,45% in ONCAB group. 1 patient in OPCAB group needed 2 graft revisions. Graft revisions were more common in OPCAB, but with no significant difference (p=0,1035. The most frequently revised graft was LAD graft in both groups. Although the percentage of grafts revised are relatively low, it is still very important to record TTFM. More than 5% of patients in both groups needed graft revision. Although TTFM does not guarantee that grafts will stay open for a prolonged period of time we certainly believe that grafts that are occluded at the time of surgery will continue to stay occluded. TTFM is especially critical in OPCAB surgery where the technical challenge of grafting is higher then in ONCAB.

  10. Trip time prediction in mass transit companies. A machine learning approach

    OpenAIRE

    João M. Moreira; Alípio Jorge; Jorge Freire de Sousa; Carlos Soares

    2005-01-01

    In this paper we discuss how trip time prediction can be useful foroperational optimization in mass transit companies and which machine learningtechniques can be used to improve results. Firstly, we analyze which departmentsneed trip time prediction and when. Secondly, we review related work and thirdlywe present the analysis of trip time over a particular path. We proceed by presentingexperimental results conducted on real data with the forecasting techniques wefound most adequate, and concl...

  11. Kinetically controlled glass transition measurement of organic aerosol thin films using broadband dielectric spectroscopy

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2018-06-01

    Full Text Available Glass transitions from liquid to semi-solid and solid phase states have important implications for reactivity, growth, and cloud-forming (cloud condensation nuclei and ice nucleation capabilities of secondary organic aerosols (SOAs. The small size and relatively low mass concentration of SOAs in the atmosphere make it difficult to measure atmospheric SOA glass transitions using conventional methods. To circumvent these difficulties, we have adapted a new technique for measuring glass-forming properties of atmospherically relevant organic aerosols. Aerosol particles to be studied are deposited in the form of a thin film onto an interdigitated electrode (IDE using electrostatic precipitation. Dielectric spectroscopy provides dipole relaxation rates for organic aerosols as a function of temperature (373 to 233 K that are used to calculate the glass transition temperatures for several cooling or heating rates. IDE-enabled broadband dielectric spectroscopy (BDS was successfully used to measure the kinetically controlled glass transition temperatures of aerosols consisting of glycerol and four other compounds with selected cooling and heating rates. The glass transition results agree well with available literature data for these five compounds. The results indicate that the IDE-BDS method can provide accurate glass transition data for organic aerosols under atmospheric conditions. The BDS data obtained with the IDE-BDS technique can be used to characterize glass transitions for both simulated and ambient organic aerosols and to model their climate effects.

  12. OT1_ipascucc_1: Understanding the Origin of Transition Disks via Disk Mass Measurements

    Science.gov (United States)

    Pascucci, I.

    2010-07-01

    Transition disks are a distinguished group of few Myr-old systems caught in the phase of dispersing their inner dust disk. Three different processes have been proposed to explain this inside-out clearing: grain growth, photoevaporation driven by the central star, and dynamical clearing by a forming giant planet. Which of these processes lead to a transition disk? Distinguishing between them requires the combined knowledge of stellar accretion rates and disk masses. We propose here to use 43.8 hours of PACS spectroscopy to detect the [OI] 63 micron emission line from a sample of 21 well-known transition disks with measured mass accretion rates. We will use this line, in combination with ancillary CO millimeter lines, to measure their gas disk mass. Because gas dominates the mass of protoplanetary disks our approach and choice of lines will enable us to trace the bulk of the disk mass that resides beyond tens of AU from young stars. Our program will quadruple the number of transition disks currently observed with Herschel in this setting and for which disk masses can be measured. We will then place the transition and the ~100 classical/non-transition disks of similar age (from the Herschel KP "Gas in Protoplanetary Systems") in the mass accretion rate-disk mass diagram with two main goals: 1) reveal which gaps have been created by grain growth, photoevaporation, or giant planet formation and 2) from the statistics, determine the main disk dispersal mechanism leading to a transition disk.

  13. Direct measurement of the transition from edge to core power coupling in a light-ion helicon source

    Science.gov (United States)

    Piotrowicz, P. A.; Caneses, J. F.; Showers, M. A.; Green, D. L.; Goulding, R. H.; Caughman, J. B. O.; Biewer, T. M.; Rapp, J.; Ruzic, D. N.

    2018-05-01

    We present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge in the form of infra-red camera imaging of a thin stainless steel target plate on the Proto-Material Exposure eXperiment device. The time-resolved images measure the two-dimensional distribution of power deposition in the helicon discharge. The discharge displays a mode transition characterized by a significant increase in the on-axis electron density and core power coupling, suppression of edge power coupling, and the formation of a fast-wave radial eigenmode. Although the self-consistent mechanism that drives this transition is not yet understood, the edge-to-core power transition displays characteristics that are consistent with the discharge entering a slow-wave anti-resonant regime. RF magnetic field measurements made across the plasma column, together with the power deposition results, provide direct evidence to support the suppression of the slow-wave in favor of core plasma production by the fast-wave in a light-ion helicon source.

  14. Time-resolved small-angle neutron scattering of a micelle-to-vesicle transition

    Energy Technology Data Exchange (ETDEWEB)

    Egelhaaf, S U [Institut Max von Laue - Paul Langevin (ILL), 38 -Grenoble (France); Schurtenberger, P [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-04-01

    Amphiphilic molecules spontaneously self-assemble in solution to form a variety of aggregates. Only limited information is available on the kinetics of the structural transitions as well as on the existence of non-equilibrium or metastable states. Aqueous mixtures of lecithin and bile salt are very interesting biological model-systems which exhibit a spontaneous transition from polymer-like mixed micelles to vesicles upon dilution. The small-angle neutron scattering (SANS) instrument D22, with its very high neutron flux and the broad range of scattering vectors covered in a single instrumental setting, allowed us for the first time to perform time-resolved scattering experiments in order to study the micelle-to-vesicle transition. The temporal evolution of the aggregate structures were followed and detailed information was obtained even on molecular length-scales. (author). 5 refs.

  15. Potential of public transit as a transportation control measure: Case studies

    Energy Technology Data Exchange (ETDEWEB)

    Sillings, M.

    1998-07-01

    This report is the final product of the Clean Air Project of the National Association of Regional Councils/NARC. It documents a nationwide study of transit projects and programs initiated in the wake of the 1990 Clean Air Act Amendments/CAAA and the Intermodal Surface Transportation Efficiency Act of 1991/ISTEA. The study purpose was to assess the experience, limitations, and value of public transit as a potential transportation control measure/TCM, i.e., generates significant air quality benefits by eliminating or reducing emissions from motor vehicles. Four in-depth case studies and six additional projects featured as innovations in transportation are offered as examples investigating the potential of transit as a TCM. These case studies and innovations highlight the efforts of ten metropolitan areas and transit agencies which have succeed in developing and implementing innovative transit strategies.

  16. Pulsatility index variations using two different transit-time flowmeters in coronary artery bypass surgery.

    Science.gov (United States)

    Nordgaard, Håvard B; Vitale, Nicola; Astudillo, Rafael; Renzulli, Attilio; Romundstad, Pål; Haaverstad, Rune

    2010-05-01

    Transit-time flow measurement is widely accepted as an intra-operative assessment in coronary artery bypass grafting (CABG). However, the two most commonly applied flowmeters, manufactured by MediStim ASA and Transonic Inc., have different default filter settings of 20 and 10 Hz, respectively. This may cause different flow measurements, which will influence the reported results. The aim was to compare pulsatility index (PI) values recorded by the MediStim and Transonic flowmeters in two different clinical settings: (1) analysis of the flow patterns recorded simultaneously by both flowmeters in the same CABGs; and (2) evaluation of flow patterns under different levels of filter settings in the same grafts. Graft flow and PI were measured using the two different flowmeters simultaneously in 19 bypass grafts. Finally, eight grafts were assessed under different digital filter settings at 5, 10, 20, 30, 50 and 100 Hz. The Transonic flowmeter provided substantially lower PI as compared with the MediStim flowmeter. By increasing the filter setting in the flowmeter, PI increased considerably. The Transonic flowmeter displayed a lower PI than the MediStim, due to a lower filter setting. In the Transonic,flow signals are filtered at a lower level, rendering a 'smoother' pattern of flow curves. Because different filter settings determine different PIs, caution must be taken when flow values and flowmeters are compared. The type of flowmeter should be indicated whenever graft flow measurements and derived indexes are provided [corrected]. Copyright 2009 European Association for Cardio-Thoracic Surgery. All rights reserved.

  17. Observation of a Time Quasicrystal and Its Transition to a Superfluid Time Crystal

    Science.gov (United States)

    Autti, S.; Eltsov, V. B.; Volovik, G. E.

    2018-05-01

    We report experimental realization of a quantum time quasicrystal and its transformation to a quantum time crystal. We study Bose-Einstein condensation of magnons, associated with coherent spin precession, created in a flexible trap in superfluid 3He-B . Under a periodic drive with an oscillating magnetic field, the coherent spin precession is stabilized at a frequency smaller than that of the drive, demonstrating spontaneous breaking of discrete time translation symmetry. The induced precession frequency is incommensurate with the drive, and hence, the obtained state is a time quasicrystal. When the drive is turned off, the self-sustained coherent precession lives a macroscopically long time, now representing a time crystal with broken symmetry with respect to continuous time translations. Additionally, the magnon condensate manifests spin superfluidity, justifying calling the obtained state a time supersolid or a time supercrystal.

  18. Morphing Wing: Experimental Boundary Layer Transition Determination and Wing Vibrations Measurements and Analysis =

    Science.gov (United States)

    Tondji Chendjou, Yvan Wilfried

    This Master's thesis is written within the framework of the multidisciplinary international research project CRIAQ MDO-505. This global project consists of the design, manufacture and testing of a morphing wing box capable of changing the shape of the flexible upper skin of a wing using an actuator system installed inside the wing. This changing of the shape generates a delay in the occurrence of the laminar to turbulent transition area, which results in an improvement of the aerodynamic performances of the morphed wing. This thesis is focused on the technologies used to gather the pressure data during the wind tunnel tests, as well as on the post processing methodologies used to characterize the wing airflow. The vibration measurements of the wing and their real-time graphical representation are also presented. The vibration data acquisition system is detailed, and the vibration data analysis confirms the predictions of the flutter analysis performed on the wing prior to wind tunnel testing at the IAR-NRC. The pressure data was collected using 32 highly-sensitive piezoelectric sensors for sensing the pressure fluctuations up to 10 KHz. These sensors were installed along two wing chords, and were further connected to a National Instrument PXI real-time acquisition system. The acquired pressure data was high-pass filtered, analyzed and visualized using Fast Fourier Transform (FFT) and Standard Deviation (SD) approaches to quantify the pressure fluctuations in the wing airflow, as these allow the detection of the laminar to turbulent transition area. Around 30% of the cases tested in the IAR-NRC wind tunnel were optimized for drag reduction by the morphing wing procedure. The obtained pressure measurements results were compared with results obtained by infrared thermography visualization, and were used to validate the numerical simulations. Two analog accelerometers able to sense dynamic accelerations up to +/-16g were installed in both the wing and the aileron boxes

  19. Time-Resolved Studies of Laser-Induced Phase Transitions in Gallium Arsenide

    Science.gov (United States)

    Siegal, Yakir

    This thesis describes a series of time-resolved experiments of the linear and nonlinear optical properties of GaAs during laser-induced phase transitions. The first set of experiments consists of a direct determination of the behavior of the linear dielectric constant at photon energies of 2.2 eV and 4.4 eV following excitation of the sample with 1.9-eV, 70-fs laser pulses spanning a fluence range from 0 to 2.5 kJ/m^2. The results from this set of experiments were used to extract the behavior of the second-order optical susceptibility from second-harmonic generation measurements made under identical excitation conditions. These experiments are unique because they provide explicit information on the behavior of intrinsic material properties--the linear and nonlinear optical susceptibilities--during laser-induced phase transitions in semiconductors without the ambiguities in interpretation that are generally inherent in reflectivity and second-harmonic generation measurements. The dielectric constant data indicate a drop in the average bonding-antibonding splitting of GaAs following the laser pulse excitation. This behavior leads to a collapse of the band-gap on a picosecond time scale for excitation at fluences near the damage threshold of 1.0 kJ/m ^2 and even faster at higher excitation fluences. The changes in the electronic band structure result from a combination of electronic screening by the excited free carriers and structural deformation of the lattice caused by the destabilization of the covalent bonds. The behavior of the second-order susceptibility shows that the material loses long-range order before the average bonding-antibonding splitting, which is more sensitive to short-range structure, changes significantly. Loss of long-range order and a drop of more than 2 eV in the average bonding-antibonding splitting are seen even at fluences below the damage threshold, a regime in which the laser-induced changes are reversible.

  20. Superhilac real-time velocity measurements

    International Nuclear Information System (INIS)

    Feinberg, B.; Meaney, D.; Thatcher, R.; Timossi, C.

    1987-03-01

    Phase probes have been placed in several external beam lines at the LBL heavy ion linear accelerator (SuperHILAC) to provide non-destructive velocity measurements independent of the ion being accelerated. The existing system has been improved to provide the following features: a display refresh rate better than twice per second, a sensitive pseudo-correlation technique to pick out the signal from the noise, simultaneous measurements of up to four ion velocities when more than one beam is being accelerated, and a touch-screen operator interface. These improvements allow the system to be used as a routine tuning aid and beam velocity monitor

  1. Phase transition traced by conductivity measurements: quantitative analysis

    DEFF Research Database (Denmark)

    Keding, Ralf; Ruessel, Christian; Tauch, Diana

    2008-01-01

    to the electrodes, all in a cylindrical geometry. The electrical resistivity of a sample in the system BaAl2B2O7 was measured during cooling between liquidus temperature (T-l) and transformation temperature (T-g) using a fixed frequency of 3.7 Hz. The melt crystallised in this temperature range during cooling...... of conductivity and the resistance changes caused by phase transformation. This enables to determine the crystal growth velocity in the temperature range between 750 and 860 degrees C in a single experiment....

  2. Triplicated P-wave measurements for waveform tomography of the mantle transition zone

    Directory of Open Access Journals (Sweden)

    S. C. Stähler

    2012-11-01

    Full Text Available Triplicated body waves sample the mantle transition zone more extensively than any other wave type, and interact strongly with the discontinuities at 410 km and 660 km. Since the seismograms bear a strong imprint of these geodynamically interesting features, it is highly desirable to invert them for structure of the transition zone. This has rarely been attempted, due to a mismatch between the complex and band-limited data and the (ray-theoretical modelling methods. Here we present a data processing and modelling strategy to harness such broadband seismograms for finite-frequency tomography. We include triplicated P-waves (epicentral distance range between 14 and 30° across their entire broadband frequency range, for both deep and shallow sources. We show that is it possible to predict the complex sequence of arrivals in these seismograms, but only after a careful effort to estimate source time functions and other source parameters from data, variables that strongly influence the waveforms. Modelled and observed waveforms then yield decent cross-correlation fits, from which we measure finite-frequency traveltime anomalies. We discuss two such data sets, for North America and Europe, and conclude that their signal quality and azimuthal coverage should be adequate for tomographic inversion. In order to compute sensitivity kernels at the pertinent high body wave frequencies, we use fully numerical forward modelling of the seismic wavefield through a spherically symmetric Earth.

  3. Nuclear transition moment measurements of neutron rich nuclei

    Science.gov (United States)

    Starosta, Krzysztof

    2009-10-01

    The Recoil Distance Method (RDM) and related Doppler Shift Attenuation Method (DSAM) are well-established tools for lifetime measurements following nuclear reactions near the Coulomb barrier. Recently, the RDM was implemented at National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University using NSCL/K"oln plunger device and a unique combination of the state-of-the-art instruments available there. Doppler-shift lifetime measurements following Coulomb excitation, knock-out, and fragmentation at intermediate energies of ˜100 MeV/u hold the promise of providing lifetime information for excited states in a wide range of unstable nuclei. So far, the method was used to investigate the collectivity of the neutron-rich ^16,18,20C, ^62,64,66Fe, ^70,72Ni, ^110,114Pd isotopes and also of the neutron-deficient N=Z ^64Ge. A significant fraction of these experiments was performed using NSCL's Segmented Germanium Array instrumented with the Digital Data Acquisition System which enables gamma-ray tracking. The impact of GRETINA and gamma-ray tracking on RDM and DSAM studies of neutron-rich nuclei will be discussed.

  4. Study of signal discrimination for timing measurements

    CERN Document Server

    Krepelkova, Marta

    2017-01-01

    The timing detectors of the CMS-TOTEM Precision Proton Spectrometer (CT-PPS) are currently read out using discrete components, separated into three boards; the first board hosts the sensors and the amplifiers, the second one hosts the discriminators and the third is dedicated to the Time to Digital Converter (TDC) and to the interface with the data acquisition system (DAQ). This work proposes a new front-end electronics for the timing detector, with sensors, amplifiers and discriminators integrated on the same board. We simulated an updated version of the amplifier together with a discriminator designed using commercial components. We decided to use an LVDS buffer as a discriminator, because of its cost, availability, speed and lo w power consumption. As a proof of concept, we used the LVDS input of an FPGA to discriminate signals produced by a detector prototype, using a radioactive source.

  5. Magnet tracking allows assessment of regional gastrointestinal transit times in children

    Directory of Open Access Journals (Sweden)

    Hedsund C

    2013-11-01

    Full Text Available Caroline Hedsund,1,2 Iben Moeller Joensson,2 Tine Gregersen,1 Lotte Fynne,1 Vincent Schlageter,3 Klaus Krogh1 1Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, 2Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark; 3Motilis Medica SA, Lausanne, Switzerland Background: Data on small intestinal transit time in healthy children are lacking, and normal values for gastric emptying and colonic transit time are sparse. Conventional methods, including radiopaque markers, scintigraphy, and PillCam™ involve radiation or require the child to swallow a large pill. The minimally invasive, radiation-free Motility Tracking System-1 (MTS-1 has been introduced for description of gastrointestinal motility in adults. The aim of the study was to evaluate the MTS-1 for assessment of gastrointestinal transit times and motility patterns in healthy children. Methods: Twenty-one healthy children (nine girls, median age 10 (range 7–12 years were included. For evaluation with MTS-1, a small magnetic pill was ingested and tracked through the gastrointestinal tract by a matrix of 16 magnetic sensors placed behind a nonmagnetic bed. The children were investigated for 8 hours after swallowing the magnetic pill and again for 4 hours the following morning. After leaving the unit, each child came back after every bowel movement to determine if the pill had been expelled. Results: Nineteen children could swallow the pill. Characteristic contraction patterns were identified for the stomach (three per minute, small intestine (9–11 per minute, and colon (4–5 per minute. Median total gastrointestinal transit time was 37.7 (range 9.5–95.8 hours, median gastric emptying time was 37 (range 2–142 minutes, median small intestinal transit time was 302 (range 164 to >454 minutes, and median colorectal transit time was 38.1 (range 5.6–90.0 hours. Conclusion: MTS-1 allows minimally invasive evaluation of gastrointestinal motility in

  6. THE KEPLER-19 SYSTEM: A TRANSITING 2.2 R{sub Circled-Plus} PLANET AND A SECOND PLANET DETECTED VIA TRANSIT TIMING VARIATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, Sarah; Fressin, Francois; Charbonneau, David; Desert, Jean-Michel; Torres, Guillermo; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fabrycky, Daniel [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Marcy, Geoffrey; Isaacson, Howard [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720 (United States); Burke, Christopher J.; Henze, Christopher; Howell, Steven B.; Bryson, Stephen T.; Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, Batavia, IL 60510 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas, Austin, TX 78712 (United States); Jenkins, Jon M., E-mail: sballard@cfa.harvard.edu [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); and others

    2011-12-20

    We present the discovery of the Kepler-19 planetary system, which we first identified from a 9.3 day periodic transit signal in the Kepler photometry. From high-resolution spectroscopy of the star, we find a stellar effective temperature T{sub eff} = 5541 {+-} 60 K, a metallicity [Fe/H] = -0.13 {+-} 0.06, and a surface gravity log(g) = 4.59 {+-} 0.10. We combine the estimate of T{sub eff} and [Fe/H] with an estimate of the stellar density derived from the photometric light curve to deduce a stellar mass of M{sub *} = 0.936 {+-} 0.040 M{sub Sun} and a stellar radius of R{sub *} = 0.850 {+-} 0.018 R{sub Sun} (these errors do not include uncertainties in the stellar models). We rule out the possibility that the transits result from an astrophysical false positive by first identifying the subset of stellar blends that reproduce the precise shape of the light curve. Using the additional constraints from the measured color of the system, the absence of a secondary source in the high-resolution spectrum, and the absence of a secondary source in the adaptive optics imaging, we conclude that the planetary scenario is more than three orders of magnitude more likely than a blend. The blend scenario is independently disfavored by the achromaticity of the transit: we measure a transit depth with Spitzer at 4.5 {mu}m of 547{sup +113}{sub -110} ppm, consistent with the depth measured in the Kepler optical bandpass of 567 {+-} 6 ppm (corrected for stellar limb darkening). We determine a physical radius of the planet Kepler-19b of R{sub p} = 2.209 {+-} 0.048 R{sub Circled-Plus }; the uncertainty is dominated by uncertainty in the stellar parameters. From radial velocity observations of the star, we find an upper limit on the planet mass of 20.3 M{sub Circled-Plus }, corresponding to a maximum density of 10.4 g cm{sup -3}. We report a significant sinusoidal deviation of the transit times from a predicted linear ephemeris, which we conclude is due to an additional perturbing body in

  7. Ages and transit times as important diagnostics of model performance for predicting carbon dynamics in terrestrial vegetation models

    Science.gov (United States)

    Ceballos-Núñez, Verónika; Richardson, Andrew D.; Sierra, Carlos A.

    2018-03-01

    The global carbon cycle is strongly controlled by the source/sink strength of vegetation as well as the capacity of terrestrial ecosystems to retain this carbon. These dynamics, as well as processes such as the mixing of old and newly fixed carbon, have been studied using ecosystem models, but different assumptions regarding the carbon allocation strategies and other model structures may result in highly divergent model predictions. We assessed the influence of three different carbon allocation schemes on the C cycling in vegetation. First, we described each model with a set of ordinary differential equations. Second, we used published measurements of ecosystem C compartments from the Harvard Forest Environmental Measurement Site to find suitable parameters for the different model structures. And third, we calculated C stocks, release fluxes, radiocarbon values (based on the bomb spike), ages, and transit times. We obtained model simulations in accordance with the available data, but the time series of C in foliage and wood need to be complemented with other ecosystem compartments in order to reduce the high parameter collinearity that we observed, and reduce model equifinality. Although the simulated C stocks in ecosystem compartments were similar, the different model structures resulted in very different predictions of age and transit time distributions. In particular, the inclusion of two storage compartments resulted in the prediction of a system mean age that was 12-20 years older than in the models with one or no storage compartments. The age of carbon in the wood compartment of this model was also distributed towards older ages, whereas fast cycling compartments had an age distribution that did not exceed 5 years. As expected, models with C distributed towards older ages also had longer transit times. These results suggest that ages and transit times, which can be indirectly measured using isotope tracers, serve as important diagnostics of model structure

  8. Influence of orocaecal transit time on hydrogen excretion after carbohydrate malabsorption

    DEFF Research Database (Denmark)

    Rumessen, J J; Hamberg, O; Gudmand-Høyer, E

    1989-01-01

    The aim of the present study was to determine whether changes in orocaecal transit time (OCTT) affect the magnitude of the breath hydrogen (H2) excretion after ingestion of unabsorbable carbohydrate. We studied eight healthy subjects by interval sampling of end expiratory H2 concentration for 12...

  9. Simultaneous Optimization of Container Ship Sailing Speed and Container Routing with Transit Time Restrictions

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Røpke, Stefan; Pisinger, David

    We introduce a decision support tool for liner shipping companies to optimally determine the sailing speed and needed fleet for a global network. As a novelty we incorporate cargo routing decisions with tight transit time restrictions on each container such that we get a realistic picture...

  10. Splitting the scotoperiod: effects on feeding behaviour, intestinal fill and digestive transit time in broiler chickens

    DEFF Research Database (Denmark)

    Duve, Linda Rosager; Steenfeldt, Sanna; Thodberg, Karen

    2011-01-01

    points (n¼192). Digestive transit time was estimated on d 29 using a chromic oxide marker; production variables and the extent of foot pad dermatitis were also recorded. 4. In the 3 h prior to a scotoperiod, feeding activity increased in chickens from DARK 8 but not DARK 4þ4. This increase was reflected...

  11. The effect of coffee on gastric emptying and oro-caecal transit time

    NARCIS (Netherlands)

    Boekema, P. J.; Lo, B.; Samsom, M.; Akkermans, L. M.; Smout, A. J.

    2000-01-01

    BACKGROUND: The consumption of coffee allegedly induces or aggravates gastrointestinal symptoms. In order to investigate the effect of coffee on gastrointestinal motility we studied the effect of coffee on gastric emptying and oro-caecal transit time. METHODS: In a randomised, controlled, cross-over

  12. Real-time monitoring of clinical processes using complex event processing and transition systems.

    Science.gov (United States)

    Meinecke, Sebastian

    2014-01-01

    Dependencies between tasks in clinical processes are often complex and error-prone. Our aim is to describe a new approach for the automatic derivation of clinical events identified via the behaviour of IT systems using Complex Event Processing. Furthermore we map these events on transition systems to monitor crucial clinical processes in real-time for preventing and detecting erroneous situations.

  13. Scintigraphic determination of gastrointestinal transit times. A comparison with breath hydrogen and radiologic methods

    DEFF Research Database (Denmark)

    Madsen, J L; Larsen, N E; Hilsted, J

    1991-01-01

    A scintigraphic method for determination of gastrointestinal transit times was compared with the breath hydrogen test and a multiple-bolus, single-radiograph technique. A close temporal association was found between the caecal appearance of radioactivity and the onset of breath hydrogen excretion...... the breath hydrogen concentration profiles....

  14. Dating Violence, Bullying, and Sexual Harassment: Longitudinal Profiles and Transitions over Time

    Science.gov (United States)

    Miller, Shari; Williams, Jason; Cutbush, Stacey; Gibbs, Deborah; Clinton-Sherrod, Monique; Jones, Sarah

    2013-01-01

    Although there is growing recognition of the problem of dating violence, little is known about how it unfolds among young adolescents who are just beginning to date. This study examined classes (subgroups) and transitions between classes over three time points based on dating violence, bullying, and sexual harassment perpetration and victimization…

  15. Colonic transit time relates to bacterial metabolism and mucosal turnover in the human gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    catabolism as reflected by microbial metabolites in urine. This results in a number of potentially deleterious protein-derived metabolites. Additionally, longer colonic transit time correlates with metabolites likely reflecting reduced renewal of the colonic mucosa. Together, this suggests that a high gut...

  16. How does subsurface retain and release stored water? An explicit estimation of young water fraction and mean transit time

    Science.gov (United States)

    Ameli, Ali; McDonnell, Jeffrey; Laudon, Hjalmar; Bishop, Kevin

    2017-04-01

    The stable isotopes of water have served science well as hydrological tracers which have demonstrated that there is often a large component of "old" water in stream runoff. It has been more problematic to define the full transit time distribution of that stream water. Non-linear mixing of previous precipitation signals that is stored for extended periods and slowly travel through the subsurface before reaching the stream results in a large range of possible transit times. It difficult to find tracers can represent this, especially if all that one has is data on the precipitation input and the stream runoff. In this paper, we explicitly characterize this "old water" displacement using a novel quasi-steady physically-based flow and transport model in the well-studied S-Transect hillslope in Sweden where the concentration of hydrological tracers in the subsurface and stream has been measured. We explore how subsurface conductivity profile impacts the characteristics of old water displacement, and then test these scenarios against the observed dynamics of conservative hydrological tracers in both the stream and subsurface. This work explores the efficiency of convolution-based approaches in the estimation of stream "young water" fraction and time-variant mean transit times. We also suggest how celerity and velocity differ with landscape structure

  17. Phase transition traced by conductivity measurements: quantitative analysis

    DEFF Research Database (Denmark)

    Keding, Ralf; Ruessel, Christian; Tauch, Diana

    2008-01-01

    starting from the electrodes. The change in the conductivity as a function of the temperature was fitted with VFT-equation for both the melt and the crystalline phase. An extrapolation of the resistance of the melt as well as of the crystalline material allows to separate the temperature dependent changes...... of conductivity and the resistance changes caused by phase transformation. This enables to determine the crystal growth velocity in the temperature range between 750 and 860 degrees C in a single experiment.......The measurement of the crystal growth velocity is carried out by analysing the change in the resistivity of the sample. The calculation of the crystal growth velocity is developed for crystal formation in the volume, crystal growth initiated at the electrodes as well as perpendicular...

  18. The cost of travel time variability: three measures with properties

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2016-01-01

    This paper explores the relationships between three types of measures of the cost of travel time variability: measures based on scheduling preferences and implicit departure time choice, Bernoulli type measures based on a univariate function of travel time, and mean-dispersion measures. We...

  19. Measurements of line overlap for resonant spoiling of x-ray lasing transitions

    International Nuclear Information System (INIS)

    Beiersdorfer, P.; Elliott, S.R.; MacGowan, B.J.; Nilsen, J.

    1994-06-01

    High-precision measurements are presented of candidate line pairs for resonant spoiling of x-ray lasing transitions in the nickel-like W 46+ , the neon-like Fe 16+ , and the neon-like La 47+ x-ray lasers. Our measurements were carried out with high-resolution crystal spectrometers, and a typical precision of 20--50 ppM was achieved. While most resonances appear insufficient for effective photo-spoiling, two resonance pairs are identified that provide a good overlap. These are the 4p 1/2 → 3d 3/2 transition in nickel-like W 46+ with the 2p 3/2 → 1s 1/2 transition in hydrogenic Al 12+ , and the 3s 1/2 → 2p 3/2 transition in neon-like La 47+ with the 1 1 S 0 -2 1 P 1 line in heliumlike Ti 20+

  20. Time resolved measurements of cathode fall in high frequency fluorescent lamps

    International Nuclear Information System (INIS)

    Hadrath, S; Garner, R C; Lieder, G H; Ehlbeck, J

    2007-01-01

    Measurements are presented of the time resolved cathode and anode falls of high frequency fluorescent lamps for a range of discharge currents typically encountered in dimming mode. Measurements were performed with the movable anode technique. Supporting spectroscopic emission measurements were made of key transitions (argon 420.1 nm and mercury 435.8 nm), whose onset coincide with cathode fall equalling the value associated with the energy, relative to the ground state, of the upper level of the respective transition. The measurements are in general agreement with the well-known understanding of dimmed lamp operation: peak cathode fall decreases with increasing lamp current and with increasing auxiliary coil heating. However, the time dependence of the measurements offers additional insight

  1. Addressing fear of crime in public space: gender differences in reaction to safety measures in train transit.

    Science.gov (United States)

    Yavuz, Nilay; Welch, Eric W

    2010-01-01

    Research has identified several factors that affect fear of crime in public space. However, the extent to which gender moderates the effectiveness of fear-reducing measures has received little attention. Using data from the Chicago Transit Authority Customer Satisfaction Survey of 2003, this study aims to understand whether train transit security practices and service attributes affect men and women differently. Findings indicate that, while the presence of video cameras has a lower effect on women's feelings of safety compared with men, frequent and on-time service matters more to male passengers. Additionally, experience with safety-related problems affects women significantly more than men. Conclusions discuss the implications of the study for theory and gender-specific policies to improve perceptions of transit safety.

  2. Measuring Passenger Travel Time Reliability Using Smart Card Data

    NARCIS (Netherlands)

    Bagherian, M.; Cats, O.; van Oort, N.; Hickman, M

    2016-01-01

    Service reliability is a key performance measure for transit agencies in increasing their service quality and thus ridership. Conventional reliability metrics are established based on vehicle movements and thus do not adequately reflect passenger’s experience. In the past few years, the growing

  3. Measuring Passenger Travel Time Reliability using Smartcard Data

    NARCIS (Netherlands)

    Bagherian, M.; Cats, O.; van Oort, N.; Hickman, M

    2016-01-01

    Service reliability is a key performance measure for transit agencies in increasing their service quality and thus ridership. Conventional reliability metrics are established based on vehicle movements and thus do not adequately reflect passenger’s experience. In the past few years, the growing

  4. Measurement of Voice Onset Time in Maxillectomy Patients

    OpenAIRE

    Hattori, Mariko; Sumita, Yuka I.; Taniguchi, Hisashi

    2014-01-01

    Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients ...

  5. FDTD based transition time dependent crosstalk analysis for coupled RLC interconnects

    International Nuclear Information System (INIS)

    Sharma, Devendra Kumar; Kaushik, Brajesh Kumar; Sharma, R. K.

    2014-01-01

    The performance of high density chips operating in the GHz range is mostly affected by on-chip interconnects. The interconnect delay depends on many factors, a few of them are inputs toggling patterns, line and coupling parasitics, input rise/fall time and source/load characteristics. The transition time of the input is of prime importance in high speed circuits. This paper addresses the FDTD based analysis of transition time effects on functional and dynamic crosstalk. The analysis is carried out for equal and unequal transition times of coupled inputs. The analysis of the effects of unequal rise time is equally important because practically, it is quite common to have mismatching in the rise time of the signals transmitting through different length wires. To demonstrate the effects, two distributed RLC lines coupled inductively and capacitively are taken into consideration. The FDTD technique is used because it gives accurate results and carries time domain analysis of coupled lines. The number of lumps in SPICE simulations is considered the same as those of spatial segments. To validate the FDTD computed results, SPICE simulations are run and results are compared. A good agreement of the computed results has been observed with respect to SPICE simulated results. An average error of less than 3.2% is observed in the computation of the performance parameters using the proposed method. (semiconductor integrated circuits)

  6. Examining the Experiences of Athletic Trainers as they transition into their First Full-Time Position

    OpenAIRE

    Stephanie M. Mazerolle; McLain Whitney; Christy Eason

    2017-01-01

    Transition to clinical practice is an important topic in athletic training, as it can be a period of time that presents challenges for the athletic trainer. Most of the research pertaining to transition to practice focuses on the skills and knowledge necessary for clinical practice, yet we know that stress can manifest from not only being an independent practitioner but also from learning how to balance one’s roles. We wanted to understand the perspective of today’s novice athletic trainers a...

  7. Establishment of a protocol for determining gastrointestinal transit time in mice using barium and radiopaque markers

    Energy Technology Data Exchange (ETDEWEB)

    Myagmarjaibuu, Bilomaa; Moon, Myeong Ju; Heo, Suk Hee; Jeong, Seo In; Jeong, Yong Yeon; Kang, Heoung Keun [Dept. of Radiology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun (Korea, Republic of); Park, Jong Seong [Dept. of Physiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Jun, Jae Yeoul [Dept. of Physiology, College of Medicine, Chosun University, Gwangju (Korea, Republic of)

    2013-01-15

    The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 μL of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ± 32.3) was significantly longer than in loperamide group I (133.2 ± 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model.

  8. Time focused measurements of roof runoff quality

    International Nuclear Information System (INIS)

    Schriewer, A.; Horn, H.; Helmreich, B.

    2008-01-01

    Runoff properties and their changes during runoff of a 14 year old zinc roof were investigated. Zinc, lead, cadmium, pH value, rain intensity and electric conductivity have been measured for a period of one year. A runoff rate of 3.73 g/m 2 a and a volume weighted mean zinc concentration of 4.9 mg/L were determined. First flush behaviour was observed in 93% of runoff events. Low rain intensities are correlating with higher zinc concentrations in runoff, whereas the duration of antecedent dry periods could not directly be linked with initial zinc concentrations

  9. Kinetics of the main phase transition of hydrated lecithin monitored by real-time x-ray diffraction

    International Nuclear Information System (INIS)

    Caffrey, M.; Bilderback, D.H.

    1984-01-01

    A method is described for observing and recording in real-time x-ray diffraction from an unoriented hydrated membrane lipid, dipalmitoylphosphatidylcholine (DPPC), through its thermotropic gel/liquid crystal phase transition. Synchrotron radiation from the Cornell High Energy Synchrotron Source (Ithaca, New York) was used as an x-ray source of extremely high brilliance and the dynamic display of the diffraction image was effected using a three-stage image intensifier tube coupled to an external fluorescent screen. The image on the output phosphor was sufficiently intense to be recorded cinematographically and to be displayed on a television monitor using a vidicon camera at 30 frames x s -1 . These measurements set an upper limit of 2 s on the DPPC gel → liquid crystal phase transition and indicate that the transition is a two-state process. The real-time method couples the power of x-ray diffraction as a structural probe with the ability to follow kinetics of structural changes. The method does not require an exogenous probe, is relatively nonperturbing, and can be used with membranes in a variety of physical states and with unstable samples. The method has the additional advantage over its static measurement counterpart in that it is more likely to detect transiently stable intermediates if present

  10. Using Start/End Timings of Spectral Transitions Between Phonemes in Concatenative Speech Synthesis

    OpenAIRE

    Toshio Hirai; Seiichi Tenpaku; Kiyohiro Shikano

    2002-01-01

    The definition of "phoneme boundary timing" in a speech corpus affects the quality of concatenative speech synthesis systems. For example, if the selected speech unit is not appropriately match to the speech unit of the required phoneme environment, the quality may be degraded. In this paper, a dynamic segment boundary defi- nition is proposed. In the definition, the concatenation point is chosen from the start or end timings of spectral transition depending on the phoneme environment at the ...

  11. Idealized flow patterns and transit times in gas/liquid contacting trays with multiple box downcomers

    International Nuclear Information System (INIS)

    D'Arcy, D.

    1977-08-01

    Trays with multiple box downcomers are often used in chemical process plants nowadays. In order to make a theoretical assessment of the mass transfer efficiency of such trays, knowledge is needed of the time spent by the liquid at various parts of the tray. An idealized but reasonable flow pattern has been assumed and the local velocities and transit times along ten equally-spaced stream lines have been computed. Numerical and graphical results are presented. (author)

  12. Time-dependent transitions with time–space noncommutativity and its implications in quantum optics

    International Nuclear Information System (INIS)

    Chandra, Nitin

    2012-01-01

    We study the time-dependent transitions of a quantum-forced harmonic oscillator in noncommutative R 1,1 perturbatively to linear order in the noncommutativity θ. We show that the Poisson distribution gets modified, and that the vacuum state evolves into a ‘squeezed’ state rather than a coherent state. The time evolutions of uncertainties in position and momentum in vacuum are also studied and imply interesting consequences for modeling nonlinear phenomena in quantum optics. (paper)

  13. Ownership of consumer electronics is associated with measures of adiposity during health transition in Vanuatu.

    Science.gov (United States)

    Sun, Cheng; Pomer, Alysa; Dancause, Kelsey N; Chan, Chim W; Olszowy, Kathryn M; Silverman, Harold; Lee, Gwang; Tarivonda, Len; Taleo, George; Regenvanu, Ralph; Kaneko, Akira; Weitz, Charles A; Garruto, Ralph M; Lum, J Koji

    2017-03-01

    The Republic of Vanuatu, like many developing nations, is undergoing a rapid health transition. Our previous study identified several behavioral risk factors for the rising prevalence of obesity. Unexpectedly, daily time spent using television and radio was revealed as a protective factor for obesity in 2007. In this study, we sought to explore associations between ownership of consumer electronics (CE) and measures of adiposity in Vanuatu in 2011. We surveyed 873 adults from five islands varying in level of economic development. Height, weight, and waist circumferences; triceps, subscapular, and suprailiac skinfolds; and percent body fat by bioelectrical impedance were measured. Ownership of eight types of CE, diet through 24-h dietary recall and leisure-time activity patterns were assessed using a questionnaire. Participants from more developed islands owned more types of CE, and revealed higher measures of adiposity on average as well as higher prevalence of obesity/central obesity. When controlling for demographic factors, and dietary and activity patterns, increased measures of adiposity and risk for obesity/central obesity were associated with ownership of cellphones, music players, televisions, video players, microwaves, and/or refrigerators. Positive correlations between CE ownership and measures of adiposity were mainly observed among men on the two most developed islands. The results of this study indicate a possible role of CE use in the rising prevalence of obesity and the shift to a sedentary lifestyle in Vanuatu and many other modernizing regions, where prevention efforts including education on healthy use of CE are imperative. © 2016 Wiley Periodicals, Inc.

  14. Scintigraphic determination of the effect of metoclopramide and morphine on small intestinal transit time

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, E.K.; Caride, V.J.; Winchenbach, K.; Troncale, F.J.; McCallum, R.W.

    1988-01-01

    To determine if a scintigraphic method could detect pharmacologic changes in small intestinal transit time (SITT), 10 male volunteers were studied at baseline and after intravenously administered metoclopramide (10 mg) and morphine (8 mg). Five of these volunteers were studied with the hydrogen breath test method for comparison. For each of the scintigraphic studies, the volunteers were positioned supine under a large-field-of-view gamma camera after ingesting an isosmotic lactulose solution containing 99mtechnetium-diethylenetriaminepentaacetic acid (DTPA). Data were collected and stored in a computer. Both gastric emptying and SITT were determined. SITT was 81 +/- 11 min (mean +/- S.E.M.; N = 10) during baseline studies, was decreased significantly to 50 +/- 6 min (N = 10; P less than 0.01) after metoclopramide, and was increased significantly to 161 +/- 15 min (N = 8; P less than 0.01) after morphine. Baseline mean values were 86.3 +/- 15 min (N = 15) for the hydrogen breath tests, 47 +/- 8 min (N = 5) for metoclopramide, and 183 +/- 16 min (N = 5) for morphine. For gastric emptying, there was no significant difference in percentage emptying at 1 hr for baseline and metochopramide (82 +/- 5% vs. 88 +/- 4%). Morphine prolonged gastric emptying at 1 hr to 63 +/- 8%. We conclude that the scintigraphic method for measuring SITT permits accurate investigation of the pharmacologic effects on intestinal motility and, in addition, may be a useful research and clinical method for SITT determination.

  15. The pursuit of new role: A study of luxury products consumption during the liminal transition into first time employment

    OpenAIRE

    Chucherd, Sunong

    2008-01-01

    Consumer behaviour research on role transition has so far been limited to the negative life changes and the changes-specific consequences towards the consumption pattern. Moreover, although young adult customers have recently been the new target customer for many luxury brands, no research has been conducted concerning the impacts of role transition during the transition into first-time employment and the role of luxury products in dealing with those effects. Liminal transition is also a new ...

  16. Sleep discontinuity and impaired sleep continuity affect transition to and from obesity over time: results from the Alameda county study.

    Science.gov (United States)

    Nordin, Maria; Kaplan, Robert M

    2010-03-01

    To investigate the impact of development in sleep continuity on transition to and from obesity over time. The study used self-reported sleep and body mass index (BMI) measures from the 1965, 1974, 1983, and 1994 waves of the longitudinal Alameda County Study. Sleep continuity was assessed by a question on whether the participants had any troubles falling or staying asleep. Change in sleep and BMI were estimated from the sleep and BMI questions in 1965 and 1994 respectively. Multinomial regression analyses were used to examine the risk/chance for a transition to and from obesity (BMI >or=30 kg/m(2)) due to development in sleep continuity. After adjustment for confounding variables, consistent sleep discontinuity both increases the risk for a transition to obesity and reduces the chance of losing weight, whereas impaired sleep continuity lowers the chance for weight loss. Effects for obesity were non-significant for those with improved sleep continuity. Consistent sleep discontinuity and impaired sleep continuity increases the risk of transition to obesity or of remaining obese.

  17. Real time measurement of air radioactivity

    International Nuclear Information System (INIS)

    Galeriu, D.; Craciunescu, T.; Teles, S.

    1998-01-01

    A Local Meteorological and Radiological Monitoring System was developed in our institute for several purposes: local monitoring, extending our experience in other location such as Cernavoda NPP and research. This system has meteorological sensors for wind speed and direction, air temperature, solar radiation, relative humidity, rainfall, dose ratemeter (Geiger-Muller counter - TIEX), Alpha-Beta Activity-in-Air Monitor (AB96), Iodine Monitor and Eberline Intelligent Ionization Chamber (FHT 6010). All data are collected by a programmable interface Delta-T Logger that is controlled by a software (ODAS - 'On-line Data Acquisition Software'). ODAS was developed in IFIN-HH. It has the capability to acquire, calculate and transmit real meteorological and radiological data through local network. The developed software controls the interface, the flux of input data through the serial port RS232 and after some processing (system, configuration, input data, connection to the network checking, etc) it creates data files. These files are transmitted on-line to our workstation or in any other place connected to Internet. Data can be collected from the logger at any time during logging. There is no need to stop logging. Data output from the logger can be controlled either from the logger's keypad or from other user terminals. ODAS is operated as follows: - First, the last written file and the date-time of acquired readings are checked. For establishing communication with logger a RS232 level signal must be sent to it. The logger wakes if asleep and sends back RDY signal. Powering the logger may take up to 100 ms to establish a correct RS232 level. Noise on the output lines occurs during this period and communication software may need to take into account such spurious signals. A command must be sent to the logger within 2 s to confirm that the last signal received is real and not spurious. Otherwise, the logger interprets the signal as noise and sleeps. The software sends further

  18. Detection of weak transitions in signal dynamics using recurrence time statistics

    International Nuclear Information System (INIS)

    Gao, J.B.; Cao Yinhe; Gu Lingyun; Harris, J.G.; Principe, J.C.

    2003-01-01

    Signal detection in noisy and nonstationary environments is very challenging. In this Letter, we study why the two types of recurrence times [Phys. Rev. Lett. 83 (1999) 3178] may be very useful for detecting weak transitions in signal dynamics. We particularly emphasize that the recurrence times of the second type may be more powerful in detecting transitions with very low energy. These features are illustrated by studying a number of speech signals with fricatives and plosives. We have also shown that the recurrence times of the first type, nevertheless, has the distinguished feature of being more robust to the noise level and less sensitive to the parameter change of the algorithm. Since throughout our study, we have not explored any features unique to the speech signals, the results shown here may indicate that these tools may be useful in many different applications

  19. Mean transit time image - a new method of analyzing brain perfusion studies

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, Z.; Ritzl, F.

    1983-05-01

    Point-by-point calculation of the mean transit time based on gamma fit was used to analyze brain perfusion studies in a vertex view. The algorithm and preliminary results in normal brain and in different stages of cerebral perfusion abnormality (ischemia, stroke, migraine, tumor, abscess) are demonstrated. In contrast to the traditional methods using fixed, a priori defined regions of interest this type of mapping of the relative regions cerebral perfusion shows more clearly the irregular outlines of the disturbance. Right to left activity ratios in the arterial part of the time-activity curves showed significant correlation with the mean transit time ratios (Q/sub 1/=1.185-0.192 Qsub(a), n=38, r=0.716, P<0.001).

  20. Time-frequency analysis of the restricted three-body problem: transport and resonance transitions

    International Nuclear Information System (INIS)

    Vela-Arevalo, Luz V; Marsden, Jerrold E

    2004-01-01

    A method of time-frequency analysis based on wavelets is applied to the problem of transport between different regions of the solar system, using the model of the circular restricted three-body problem in both the planar and the spatial versions of the problem. The method is based on the extraction of instantaneous frequencies from the wavelet transform of numerical solutions. Time-varying frequencies provide a good diagnostic tool to discern chaotic trajectories from regular ones, and we can identify resonance islands that greatly affect the dynamics. Good accuracy in the calculation of time-varying frequencies allows us to determine resonance trappings of chaotic trajectories and resonance transitions. We show the relation between resonance transitions and transport in different regions of the phase space

  1. Particle identification using the time-over-threshold method in the ATLAS Transition Radiation Tracker

    International Nuclear Information System (INIS)

    Akesson, T.; Arik, E.; Assamagan, K.; Baker, K.; Barberio, E.; Barberis, D.; Bertelsen, H.; Bytchkov, V.; Callahan, J.; Catinaccio, A.; Danielsson, H.; Dittus, F.; Dolgoshein, B.; Dressnandt, N.; Ebenstein, W.L.; Eerola, P.; Farthouat, P.; Froidevaux, D.; Grichkevitch, Y.; Hajduk, Z.; Hansen, J.R.; Keener, P.T.; Kekelidze, G.; Konovalov, S.; Kowalski, T.; Kramarenko, V.A.; Krivchitch, A.; Laritchev, A.; Lichard, P.; Lucotte, A.; Lundberg, B.; Luehring, F.; Mailov, A.; Manara, A.; McFarlane, K.; Mitsou, V.A.; Morozov, S.; Muraviev, S.; Nadtochy, A.; Newcomer, F.M.; Olszowska, J.; Ogren, H.; Oh, S.H.; Peshekhonov, V.; Rembser, C.; Romaniouk, A.; Rousseau, D.; Rust, D.R.; Schegelsky, V.; Sapinski, M.; Shmeleva, A.; Smirnov, S.; Smirnova, L.N.; Sosnovtsev, V.; Soutchkov, S.; Spiridenkov, E.; Tikhomirov, V.; Van Berg, R.; Vassilakopoulos, V.; Wang, C.; Williams, H.H.

    2001-01-01

    Test-beam studies of the ATLAS Transition Radiation Tracker (TRT) straw tube performance in terms of electron-pion separation using a time-over-threshold method are described. The test-beam data are compared with Monte Carlo simulations of charged particles passing through the straw tubes of the TRT. For energies below 10 GeV, the time-over-threshold method combined with the standard transition-radiation cluster-counting technique significantly improves the electron-pion separation in the TRT. The use of the time-over-threshold information also provides some kaon-pion separation, thereby significantly enhancing the B-physics capabilities of the ATLAS detector

  2. Enzyme reactions and their time resolved measurements

    International Nuclear Information System (INIS)

    Hajdu, Janos

    1990-01-01

    This paper discusses experimental strategies in data collection with the Laue method and summarises recent results using synchrotron radiation. Then, an assessment is made of the progress towards time resolved studies with protein crystals and the problems that remain. The paper consists of three parts which respectively describe some aspects of Laue diffraction, recent examples of structural results from Laue diffraction, and kinetic Laue crystallography. In the first part, characteristics of Laue diffraction is discussed first, focusing on the harmonics problems, spatials problem, wavelength normalization, low resolution hole, data completeness, and uneven coverage of reciprocal space. Then, capture of the symmetry unique reflection set is discussed focusing on the effect of wavelength range on the number of reciprocal lattice points occupying diffracting positions, effect of crystal to film distance and the film area and shape on the number of reflections captured, and effect of crystal symmetry on the number of unique reflections within the number of reflections captured. The second part addresses the determination of the structure of turkey egg white lysozyme, and calcium binding in tomato bushy stunt virus. The third part describes the initiation of reactions in enzyme crystals, picosecond Laue diffraction at high energy storage rings, and detectors. (N.K.)

  3. Measured Boundary Layer Transition and Rotor Hover Performance at Model Scale

    Science.gov (United States)

    Overmeyer, Austin D.; Martin, Preston B.

    2017-01-01

    An experiment involving a Mach-scaled, 11:08 f t: diameter rotor was performed in hover during the summer of 2016 at NASA Langley Research Center. The experiment investigated the hover performance as a function of the laminar to turbulent transition state of the boundary layer, including both natural and fixed transition cases. The boundary layer transition locations were measured on both the upper and lower aerodynamic surfaces simultaneously. The measurements were enabled by recent advances in infrared sensor sensitivity and stability. The infrared thermography measurement technique was enhanced by a paintable blade surface heater, as well as a new high-sensitivity long wave infrared camera. The measured transition locations showed extensive amounts, x=c>0:90, of laminar flow on the lower surface at moderate to high thrust (CT=s > 0:068) for the full blade radius. The upper surface showed large amounts, x=c > 0:50, of laminar flow at the blade tip for low thrust (CT=s boundary layer transition models in CFD and rotor design tools. The data is expected to be used as part of the AIAA Rotorcraft SimulationWorking Group

  4. Measurements of transition probabilities in the range from vacuum ultraviolet to infrared

    International Nuclear Information System (INIS)

    Peraza Fernandez, M.C.

    1992-01-01

    In this memory we describe the design, testing and calibration of different spectrometers to measure transition probabilities from the vacuum ultraviolet to the infrared spectral region. For the infrared measurements we have designed and performed a phase sensitive detection system, using an InGaAs photodiode like detector. With this system we have determined the transition probabilities of infrared lines of KrI and XeI. For these lines we haven't found previous measurements. In the vacuum ultraviolet spectral region we have designed a 3 m normal incidence monochromator where we have installed an optical multichannel analyzer. We have tested its accurate working, obtaining the absorption spectrum of KrI. In the visible region we have obtained the emission spectrum of Al using different spectral: hallow-cathode lamp and Nd: YAG laser produced Al plasma. With these spectra we have determined different atomic parameters like transition probabilities and electron temperatures.(author). 83 refs

  5. Challenges to Rainfall-Runoff and Transit Time Distribution Modeling Within the Southeastern Coastal Plain, USA

    Science.gov (United States)

    Decker, P.; Cohen, M. J.; Jawitz, J. W.

    2017-12-01

    Previous hydrologic studies primarily focus on processes related to montane catchments with significant runoff ratios, low evapotranspiration rates, and reasonably short travel times. There is a significant lack of research for hydrologic processes occurring within the United States Southeastern Coastal Plain landscape where low-relief and high rates of evapotranspiration impact water fluxes. Hydrologic modeling efforts within this region may elucidate possible interactions and timescales of solute travel where much of the landscape is managed for agricultural crops, namely plantation forestry. A long-term paired watershed study carried out in northern Florida monitored two second-order blackwater streams for five years. Rainfall-runoff models for both catchments were created using daily discharge, precipitation, and modeled evapotranspiration as input parameters. Best fit occurred (NSE = 0.8) when the catchments were modeled as two-storage (shallow and deep) reservoirs in parallel and overland flow was allowed to contribute to streamflow in periods were shallow groundwater storage was at capacity. In addition, streamflow and rainfall chloride concentrations were used to model in-variable transit time distributions using spectral methods. In both catchments this transit time was unresolvable because output spectral power exceeded input spectral power, a result assumed to be driven by the evaporative demand of the region. A modeled chloride time series from random input concentration and modeled output through the rainfall-runoff model was used to alter the evaporation ratio. Once evaporation rates equaled known rates found in cool, high-relief catchments, spectral analysis illustrated higher input spectral power and therefore resolvable transit times. Findings from this study illustrate significant effects from evaporation within the catchment - often exceeding the signal from the background catchment process itself. Calculations illustrate a proposed mean transit

  6. Accelerating the transit time of barium sulphate suspensions in small bowel examinations

    International Nuclear Information System (INIS)

    Summers, David S.; Roger, Mark D.; Allan, Paul L.; Murchison, John T.

    2007-01-01

    Purpose: To determine whether hyperosmolar and effervescent agents proven individually to accelerate transit time in the barium small bowel examination have an additive effect when combined, surpassing that of either agent alone. Materials and methods: One hundred and forty-nine patients were randomised to four groups. Three hundred milliliters of barium sulphate alone was given to the first group. Fifteen milliliters of iodinated hyperosmolar contrast agent (Gastrografin, meglumine/sodium diatrizoate, Schering) was given in addition to barium sulphate to the second group while six packets of effervescent granules (Carbex, Ferring) were added for the third group. The final group was given a combination of both additives and barium sulphate. The time taken following ingestion for the contrast column to reach the caecum, as assessed by frequent interval fluoroscopy, was recorded. A subgroup of 32 patients were selected randomly from the four groups, 8 from each and assessed for quality of examination. Statistical assessments were made using Kruskal-Wallis and Mann-Whitney tests. Results: One hundred and nineteen patients were analysed after exclusions. The addition of accelerant to barium sulphate, both individually and in combination significantly reduced the small bowel transit time (p < 0.001). No significant difference existed between the additives when used with barium alone. The combined group had significantly faster transit times compared to the hyperosmolar group (p = 0.02). Differences between combined and effervescent groups tended towards significance (p = 0.09). No significant difference existed between groups when examination quality was assessed. Conclusion: These results suggest that the addition of combined effervescent and hyperosmolar agents to the barium suspension may significantly shorten the small bowel transit time without adversely affecting examination quality. This has implications for patient acceptability of the examination as well as

  7. CHARACTERIZATION OF THE K2-19 MULTIPLE-TRANSITING PLANETARY SYSTEM VIA HIGH-DISPERSION SPECTROSCOPY, AO IMAGING, AND TRANSIT TIMING VARIATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Norio; Hori, Yasunori; Kusakabe, Nobuhiko; Takeda, Yoichi; Tamura, Motohide [Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan); Hirano, Teruyuki [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Fukui, Akihiko; Yanagisawa, Kenshi [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan); Sanchis-Ojeda, Roberto [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ryu, Tsuguru; Onitsuka, Masahiro [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan); Kudo, Tomoyuki [Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720 (United States); Delrez, Laetitia; Gillon, Michael; Jehin, Emmanuel [Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bat. B5C, B-4000 Liège (Belgium); McCormac, James [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Holman, Matthew [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Izumiura, Hideyuki, E-mail: norio.narita@nao.ac.jp [SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan)

    2015-12-10

    K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ∼7 R{sub ⊕} (inner planet b) and ∼4 R{sub ⊕} (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2 m telescope. We find that the host star is a relatively old (≥8 Gyr) late G-type star (T{sub eff} ∼ 5350 K, M{sub s} ∼ 0.9 M{sub ⊙}, and R{sub s} ∼ 0.9 R{sub ⊙}). We do not find any contaminating faint objects near the host star that could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2 m telescope, TRAPPISTCAM on the TRAPPIST 0.6 m telescope, and MuSCAT on the OAO 1.88 m telescope. We confirm the presence of transit timing variations (TTVs), as previously reported by Armstrong and coworkers. We model the observed TTVs of the inner planet using the synodic chopping formulae given by Deck and Agol. We find two statistically indistinguishable solutions for which the period ratios (P{sub c}/P{sub b}) are located slightly above and below the exact 3:2 commensurability. Despite the degeneracy, we derive the orbital period of the inner planet P{sub b} ∼ 7.921 days and the mass of the outer planet M{sub c} ∼ 20 M{sub ⊕}. Additional transit photometry (especially for the outer planet) as well as precise radial-velocity measurements would be helpful to break the degeneracy and to determine the mass of the inner planet.

  8. Examining the Experiences of Athletic Trainers as they transition into their First Full-Time Position

    Directory of Open Access Journals (Sweden)

    Stephanie M. Mazerolle

    2017-04-01

    Full Text Available Transition to clinical practice is an important topic in athletic training, as it can be a period of time that presents challenges for the athletic trainer. Most of the research pertaining to transition to practice focuses on the skills and knowledge necessary for clinical practice, yet we know that stress can manifest from not only being an independent practitioner but also from learning how to balance one’s roles. We wanted to understand the perspective of today’s novice athletic trainers and how they feel in their first full-time position, specifically relating to their professional development and establishment or maintenance of work-life balance (WLB. Using a qualitative paradigm, we phone interviewed athletic trainers who were categorized as career starters by the National Athletic Trainers’ Association. Using a purposive recruitment strategy we were able to recruit 20 (12 female, 8 male athletic trainers meeting this classification. General inductive analyses were used to code the data from our interviews, and we satisfied credibility though saturation of the data, peer review, and researcher triangulations during the coding process. Our findings suggest that while confidence in clinical skills is apparent, some of the more administrative aspects of clinical practice present challenges. We found that various employment settings offered various expectations or challenges that had the potential to impact WLB. A blend of professional and organizational processes helped transition the athletic trainer, and although both were helpful each also could be bolstered to improve transitioning for the newly credentialed athletic trainer. Employers of early career starters should be aware of the stress related to transition to practice, and the time it can take to acclimate.

  9. Correlation Between Timed Barium Esophagogram and Esophageal Transit Scintigraphy Results in Achalasia.

    Science.gov (United States)

    Park, Yoo Mi; Jeon, Han Ho; Park, Jae Jun; Kim, Jie-Hyun; Youn, Young Hoon; Park, Hyojin

    2015-08-01

    Timed barium esophagogram (TBE) and esophageal transit scintigraphy (ETS) have been adopted as useful ways to evaluate achalasia patients. TBE has merit as a simple, non-invasive, and convenient method. The study sought to compare the results of these two tests and verify their usefulness in evaluating treatment response. In addition, we assessed whether TBE could effectively replace ETS through correlation analysis. The medical records of 50 achalasia patients treated between September 2011 and June 2014 were reviewed retrospectively. The height and width of the barium column at 1, 2, and 5 min were measured by TBE. Half-life (T 1/2, min) and R 30 (percentage of remaining radioactivity 30 s after radioisotope ingestion) were measured by ETS. Both tests were performed before and after treatment, and the tests were carried out 1 and 2 days after procedures. And we analyzed the correlation between the parameters from the two tests. The parameters of TBE and ETS were improved after treatment (p treatment, the height and width results at 5 min from TBE positively correlated with the T 1/2 parameter from ETS (correlation coefficients of 0.59 and 0.75, respectively). After treatment, the correlation coefficients between the 5-min height and width of the barium column by TBE and T 1/2 by ETS were 0.55 and 0.46, respectively. Both TBE and ETS are useful modalities in assessing esophageal emptying and response to achalasia treatment. TBE and ETS results have a statistically significant correlation both pre- and post-treatment. We suggest that TBE could effectively replace ETS for the assessment of achalasia.

  10. Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans.

    Science.gov (United States)

    El Oufir, L; Flourié, B; Bruley des Varannes, S; Barry, J L; Cloarec, D; Bornet, F; Galmiche, J P

    1996-06-01

    To investigate whether transit time could influence H2 consuming flora and certain indices of colonic bacterial fermentation. Eight healthy volunteers (four methane excretors and four non-methane excretors) were studied for three, three week periods during which they received a controlled diet alone (control period), and then the same diet with cisapride or loperamide. At the end of each period, mean transit time (MTT) was estimated, an H2 lactulose breath test was performed, and stools were analysed. In the control period, transit time was inversely related to faecal weight, sulphate reducing bacteria counts, concentrations of total short chain fatty acids (SCFAs), propionic and butyric acids, and H2 excreted in breath after lactulose ingestion. Conversely, transit time was positively related to faecal pH and tended to be related to methanogen counts. Methanogenic bacteria counts were inversely related to those of sulphate reducing bacteria and methane excretors had slower MTT and lower sulphate reducing bacteria counts than non-methane excretors. Compared with the control period, MTT was significantly shortened (p < 0.05) by cisapride and prolonged (p < 0.05) by loperamide (73 (11) hours, 47 (5) hours and 147 (12) hours for control, cisapride, and loperamide, respectively, mean (SD)). Cisapride reduced transit time was associated with (a) a significant rise in faecal weight, sulphate reducing bacteria, concentrations of total SCFAs, and propionic and butyric acids and breath H2 as well as (b) a significant fall in faecal pH and breath CH4 excretion, and (c) a non-significant decrease in the counts of methanogenic bacteria. Reverse relations were roughly the same during the loperamide period including a significant rise in the counts of methanogenic bacteria and a significant fall in those of sulphate reducing bacteria. Transit time differences between healthy volunteers are associated with differences in H2 consuming flora and certain indices of colonic

  11. Financial Distress Prediction Using Discrete-time Hazard Model and Rating Transition Matrix Approach

    Science.gov (United States)

    Tsai, Bi-Huei; Chang, Chih-Huei

    2009-08-01

    Previous studies used constant cut-off indicator to distinguish distressed firms from non-distressed ones in the one-stage prediction models. However, distressed cut-off indicator must shift according to economic prosperity, rather than remains fixed all the time. This study focuses on Taiwanese listed firms and develops financial distress prediction models based upon the two-stage method. First, this study employs the firm-specific financial ratio and market factors to measure the probability of financial distress based on the discrete-time hazard models. Second, this paper further focuses on macroeconomic factors and applies rating transition matrix approach to determine the distressed cut-off indicator. The prediction models are developed by using the training sample from 1987 to 2004, and their levels of accuracy are compared with the test sample from 2005 to 2007. As for the one-stage prediction model, the model in incorporation with macroeconomic factors does not perform better than that without macroeconomic factors. This suggests that the accuracy is not improved for one-stage models which pool the firm-specific and macroeconomic factors together. In regards to the two stage models, the negative credit cycle index implies the worse economic status during the test period, so the distressed cut-off point is adjusted to increase based on such negative credit cycle index. After the two-stage models employ such adjusted cut-off point to discriminate the distressed firms from non-distressed ones, their error of misclassification becomes lower than that of one-stage ones. The two-stage models presented in this paper have incremental usefulness in predicting financial distress.

  12. Does the Timing of Transition Matter? Comparison of German Students' Self-Perceptions before and after Transition to Secondary School

    Science.gov (United States)

    Arens, A. Katrin; Yeung, Alexander Seeshing; Craven, Rhonda G.; Watermann, Rainer; Hasselhorn, Marcus

    2013-01-01

    The often observed decline in students' self-perceptions across transition to secondary school after grade 6 is often attributed to students' entry to puberty. This study aims to examine whether lowered self-perceptions can be observed after transition in Germany which occurs after grade 4 and thus takes place before puberty. Fifth graders (N =…

  13. Reciprocating Probe Measurements of L-H Transition in LHCD H-mode on EAST

    DEFF Research Database (Denmark)

    Peng, Liu; Guosheng, Xu; Huiqian, Wang

    2013-01-01

    that the power loss P loss was comparable during the L-H transition, by comparing the adjacent L-mode and H-mode discharge. The Dα emission, Te and ne decreased rapidly in the time scale of about 1 ms, and the radial electric field Er turned positive in this process near the last closed flux surface. Multiple L......-H-L transitions were observed during a single shot when the applied LHW power was marginal to the threshold. The floating potential (Vf) had negative spikes corresponding with the Dα signal, and Er oscillation evolved into several intermittent negative spikes just before the L-H transition. In some shots......, dithering was observed just before the L-H transition....

  14. Temperature-Controlled High-Speed AFM: Real-Time Observation of Ripple Phase Transitions.

    Science.gov (United States)

    Takahashi, Hirohide; Miyagi, Atsushi; Redondo-Morata, Lorena; Scheuring, Simon

    2016-11-01

    With nanometer lateral and Angstrom vertical resolution, atomic force microscopy (AFM) has contributed unique data improving the understanding of lipid bilayers. Lipid bilayers are found in several different temperature-dependent states, termed phases; the main phases are solid and fluid phases. The transition temperature between solid and fluid phases is lipid composition specific. Under certain conditions some lipid bilayers adopt a so-called ripple phase, a structure where solid and fluid phase domains alternate with constant periodicity. Because of its narrow regime of existence and heterogeneity ripple phase and its transition dynamics remain poorly understood. Here, a temperature control device to high-speed atomic force microscopy (HS-AFM) to observe dynamics of phase transition from ripple phase to fluid phase reversibly in real time is developed and integrated. Based on HS-AFM imaging, the phase transition processes from ripple phase to fluid phase and from ripple phase to metastable ripple phase to fluid phase could be reversibly, phenomenologically, and quantitatively studied. The results here show phase transition hysteresis in fast cooling and heating processes, while both melting and condensation occur at 24.15 °C in quasi-steady state situation. A second metastable ripple phase with larger periodicity is formed at the ripple phase to fluid phase transition when the buffer contains Ca 2+ . The presented temperature-controlled HS-AFM is a new unique experimental system to observe dynamics of temperature-sensitive processes at the nanoscopic level. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models

    Energy Technology Data Exchange (ETDEWEB)

    Fabrycky, Daniel C.; /UC, Santa Cruz; Ford, Eric B.; /Florida U.; Steffen, Jason H.; /Fermilab; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Moorhead, Althea V.; /Florida U.; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Bryson, Steve; /NASA, Ames; Buchhave, Lars A.; /Bohr Inst. /Copenhagen U.; Christiansen, Jessie L.; /SETI Inst., Mtn. View /NASA, Ames /Caltech

    2012-01-01

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present 4 sets of lightcurves from the Kepler spacecraft, which each show multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems architectures, even in cases for which high-precision Doppler follow-up is impractical.

  16. Transition into daylight saving time influences the fragmentation of the rest-activity cycle

    Directory of Open Access Journals (Sweden)

    Tuulio-Henriksson Annamari

    2006-01-01

    Full Text Available Abstract Background Daylight saving time is widely adopted. Little is known about its influence on the daily rest-activity cycles. We decided to explore the effects of transition into daylight saving time on the circadian rhythm of activity. Methods We monitored the rest-activity cycles with the use of wrist-worn accelerometer on a sample of ten healthy adults for ten days around the transition into summer time. Identical protocols were carried out on the same individuals in two consecutive years, yielding data on 200 person-days for analysis in this study. Results There was no significant effect on the rest-activity cycle in the sample as a whole. Fragmentation of the rest-activity cycle was enhanced in a subgroup of persons having sleep for eight hours or less (P = 0.04 but reduced in those who preferred to sleep for more than eight hours per night (P = 0.05. The average level of motor activity was increased in persons having the morning preference for daily activity patterns (P = 0.01. Conclusion Transition into daylight saving time may have a disruptive effect on the rest-activity cycle in those healthy adults who are short-sleepers or more of the evening type.

  17. Measurement of the Dead-Time in a Multichannel Analyser

    DEFF Research Database (Denmark)

    Mortensen, L.; Olsen, J.

    1973-01-01

    By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses.......By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses....

  18. Non-adiabatic transition of the fissioning nucleus at scission: the time scale

    International Nuclear Information System (INIS)

    Carjan, N.; Rizea, M.

    2012-01-01

    The sudden approximation has been recently used to calculate the microscopic scission-properties during low-energy fission of 236 U. In this approach the scission process, i.e., the transition from two fragments connected by a thin neck to two separated fragments was considered to happen suddenly. The approach is stationary (the time evolution is not explicitly treated) and it only involves the two sets of neutron eigenstates for the two nuclear configurations considered: just before scission (α i ) and immediately after scission (α f ). The purpose of the present paper is to go beyond this mathematical approximation considering the real physical situation in which the above mentioned transition takes place in a time interval ΔT ≠ 0. For this we need to follow the evolution from α i to αf of all occupied neutron states by solving numerically the two-dimensional time-dependent Schroedinger equation with time-dependent potential. Calculations are performed for mass divisions from A L = 70 to A L = 118 (A L being the light fragment mass) taking into account all the neutron states (Ω = 1/2, 3/2,..., 11/2) that are bound in 236 U at α i . The diabatic-dissipative dynamics of the neck rupture is very complicated and its exact duration is un-known. ΔT is therefore taken as parameter having values from 0.25 x 10 -22 to 6 x 10 -22 sec. The resulting scission neutron multiplicities - sc and primary fragments' excitation energies E sc * are compared with those obtained in the frame of the sudden approximation (that corresponds to ΔT = 0). As expected, shorter is the transition time more excited are the fragments and more neutrons are emitted, the sudden approximation being an upper limit. For ΔT = 10 -22 sec, which is a realistic value, the time dependent results are 20% below this limit. For transition times longer than 5 x 10 -22 sec the adiabatic limit is reached: no scission neutrons are emitted anymore and the excitation energy at α f is negligible. The

  19. Time evolution and dynamical phase transitions at a critical time in a system of one-dimensional bosons after a quantum quench.

    Science.gov (United States)

    Mitra, Aditi

    2012-12-28

    A renormalization group approach is used to show that a one-dimensional system of bosons subject to a lattice quench exhibits a finite-time dynamical phase transition where an order parameter within a light cone increases as a nonanalytic function of time after a critical time. Such a transition is also found for a simultaneous lattice and interaction quench where the effective scaling dimension of the lattice becomes time dependent, crucially affecting the time evolution of the system. Explicit results are presented for the time evolution of the boson interaction parameter and the order parameter for the dynamical transition as well as for more general quenches.

  20. Wigner time-delay distribution in chaotic cavities and freezing transition.

    Science.gov (United States)

    Texier, Christophe; Majumdar, Satya N

    2013-06-21

    Using the joint distribution for proper time delays of a chaotic cavity derived by Brouwer, Frahm, and Beenakker [Phys. Rev. Lett. 78, 4737 (1997)], we obtain, in the limit of the large number of channels N, the large deviation function for the distribution of the Wigner time delay (the sum of proper times) by a Coulomb gas method. We show that the existence of a power law tail originates from narrow resonance contributions, related to a (second order) freezing transition in the Coulomb gas.

  1. The transition between monostable and bistable states induced by time delay in intracellular calcium oscillation

    International Nuclear Information System (INIS)

    Duan, Wei-Long

    2013-01-01

    The revised role of the time delay of active processes with colored noises of transmission of intracellular Ca 2+ in intracellular calcium oscillation (ICO) is investigated by means of a first-order algorithm based on stochastic simulation. The simulation results indicate that time delay induces a double critical phenomenon and a transition between the monostable and bistable states of the ICO system. In addition, as the time delay increases, for a cytosolic Ca 2+ concentration with weak colored noises there appears a calcium burst, and the Ca 2+ concentration of the calcium store shows nonmonotonic variation. (paper)

  2. Polynomial-time Algorithms for Computing Distances of Fuzzy Transition Systems

    OpenAIRE

    Chen, Taolue; Han, Tingting; Cao, Yongzhi

    2017-01-01

    Behaviour distances to measure the resemblance of two states in a (nondeterministic) fuzzy transition system have been proposed recently in the literature. Such a distance, defined as a pseudo-ultrametric over the state space of the model, provides a quantitative analogue of bisimilarity. In this paper, we focus on the problem of computing these distances. We first extend the definition of the pseudo-ultrametric by introducing discount such that the discounting factor being equal to 1 capture...

  3. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. I. MEASURING PHOTOMETRIC ECCENTRICITIES OF INDIVIDUAL TRANSITING PLANETS

    International Nuclear Information System (INIS)

    Dawson, Rebekah I.; Johnson, John Asher

    2012-01-01

    Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the 'cold' Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial-velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial-velocity follow-up of most. Here, we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star's density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations—part of the 'photoeccentric' light curve signature of a planet's eccentricity—even with long-cadence Kepler photometry and loosely constrained stellar parameters. A Markov Chain Monte Carlo exploration of parameter posteriors naturally marginalizes over the periapse angle and automatically accounts for the transit probability. To demonstrate, we use three published transit light curves of HD 17156 b to measure an eccentricity of e = 0.71 +0.16 –0.09 , in good agreement with the discovery value e = 0.67 ± 0.08 based on 33 radial-velocity measurements. We present two additional tests using Kepler data. In each case, the technique proves to be a viable method of measuring exoplanet eccentricities and their confidence intervals. Finally, we argue that this method is the most efficient, effective means of identifying the extremely eccentric, proto-hot Jupiters predicted by Socrates et al.

  4. Measurements of excited-state-to-excited-state transition probabilities and photoionization cross-sections using laser-induced fluorescence and photoionization signals

    International Nuclear Information System (INIS)

    Shah, M.L.; Sahoo, A.C.; Pulhani, A.K.; Gupta, G.P.; Dikshit, B.; Bhatia, M.S.; Suri, B.M.

    2014-01-01

    Laser-induced photoionization and fluorescence signals were simultaneously observed in atomic samarium using Nd:YAG-pumped dye lasers. Two-color, three-photon photoionization and two-color fluorescence signals were recorded simultaneously as a function of the second-step laser power for two photoionization pathways. The density matrix formalism has been employed to analyze these signals. Two-color laser-induced fluorescence signal depends on the laser powers used for the first and second-step transitions as well as the first and second-step transition probability whereas two-color, three-photon photoionization signal depends on the third-step transition cross-section at the second-step laser wavelength along with the laser powers and transition probability for the first and second-step transitions. Two-color laser-induced fluorescence was used to measure the second-step transition probability. The second-step transition probability obtained was used to infer the photoionization cross-section. Thus, the methodology combining two-color, three-photon photoionization and two-color fluorescence signals in a single experiment has been established for the first time to measure the second-step transition probability as well as the photoionization cross-section. - Highlights: • Laser-induced photoionization and fluorescence signals have been simultaneously observed. • The density matrix formalism has been employed to analyze these signals. • Two-color laser-induced fluorescence was used to measure the second-step transition probability. • The second-step transition probability obtained was used to infer the photoionization cross-section. • Transition probability and photoionization cross-section have been measured in a single experiment

  5. Pulmonary blood volume and transit time in cirrhosis: relation to lung function

    DEFF Research Database (Denmark)

    Møller, Søren; Burchardt, H; Øgard, CG

    2006-01-01

    BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis....... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis...

  6. Measurement of peripheral electron temperature by electron cyclotron emission during the H-mode transition in JFT-2M tokamak

    International Nuclear Information System (INIS)

    Hoshino, Katsumichi; Yamamoto, Takumi; Kawashima, Hisato

    1987-01-01

    Time evolution and profile of peripheral electron temperature during the H-mode like transition in a tokamak plasma is measured using the second and third harmonic of electron cyclotron emission (ECE). The so called ''H-mode'' state which has good particle/energy confinement is characterized by sudden decrease in the spectral line intensity of deuterium molecule. Such a sudden decrease in the line intensity of D α with good energy confinement is found not only in divertor discharges, but also in limiter dischargs in JFT-2M tokamak. It is found by the measurement of ECE that the peripheral electron temperature suddenly increases in both of such phases. The relation between H-transition and the peripheral electron temperature or its profile is investigated. (author)

  7. The Use of Stable Isotope Tracers to Quantify the Transit Time Distribution of Water

    Science.gov (United States)

    Gray, T. M.; Troch, P. A. A.

    2016-12-01

    Water pollution is an important societal problem because it can have harmful effects on human and ecological health. In order to improve water quality, scientists must develop land management methods that can avoid or mitigate environmental pollution. State of the art tools to develop such methods are flow and transport models that trace water and other solutes through the landscape. These models deliver important information that can lead to remediation efforts, and improve the quality of water for humans, plants, and animals. However, these models may be difficult to apply since many details about the catchment may not be available. Instead, a lumped approach is often used to find the water transit time using stable isotope tracers such as 18O and 2H that are naturally applied by precipitation to a catchment. The transit time distribution of water is an important indicator for the amount of solutes soil water and groundwater can contain, and thus a predictor of water quality. We conducted a 2-week long experiment using a tilted weighing lysimeter at Biosphere 2 to observe the breakthrough curves of deuterium and specific artificial DNA particles. We show that hydrological parameters can be computed in order to provide an estimate for the transit time distribution of deuterium. The convolution integral is then used to determine the distribution of the water transit time in the system. Unfortunately, stable isotopes such as deuterium make it difficult to pinpoint a specific flowpath since they naturally occur in the environment. Recent studies have shown that DNA tracers are able to trace water through the landscape. We found that DNA has a similar breakthrough curve happening at similar timescales as the deuterium. Therefore, DNA tracers may be able to identify sources of nonpoint source pollution in the future.

  8. Transit time magnetic pumping experiments in the proto-cleo stellarator

    International Nuclear Information System (INIS)

    Millar, W.

    1975-04-01

    Experiments are described in which magnetic field perturbations at frequencies approximately 100 kHz, of the type required for Transit Time Magnetic Pumping, are applied to the PROTO-CLEO stellarator. The chief effect is an increase in the plasma loss rate, which is investigated in some detail. The importance of electrostatic fields is discussed, and attention is drawn to the possibility of operating in a region not explored here, with long wavelength and low frequency. (author)

  9. Changes to Workflow and Process Measures in the PICU During Transition From Semi to Full Electronic Health Record.

    Science.gov (United States)

    Salib, Mina; Hoffmann, Raymond G; Dasgupta, Mahua; Zimmerman, Haydee; Hanson, Sheila

    2015-10-01

    Studies showing the changes in workflow during transition from semi to full electronic medical records are lacking. This objective study is to identify the changes in workflow in the PICU during transition from semi to full electronic health record. Prospective observational study. Children's Hospital of Wisconsin Institutional Review Board waived the need for approval so this study was institutional review board exempt. This study measured clinical workflow variables at a 72-bed PICU during different phases of transition to a full electronic health record, which occurred on November 4, 2012. Phases of electronic health record transition were defined as follows: pre-electronic health record (baseline data prior to transition to full electronic health record), transition phase (3 wk after electronic health record), and stabilization (6 mo after electronic health record). Data were analyzed for the three phases using Mann-Whitney U test with a two-sided p value of less than 0.05 considered significant. Seventy-two bed PICU. All patients in the PICU were included during the study periods. Five hundred and sixty-four patients with 2,355 patient days were evaluated in the three phases. Duration of rounds decreased from a median of 9 minutes per patient pre--electronic health record to 7 minutes per patient post electronic health record. Time to final note decreased from 2.06 days pre--electronic health record to 0.5 days post electronic health record. Time to first medication administration after admission also decreased from 33 minutes pre--electronic health record and 7 minutes post electronic health record. Time to Time to medication reconciliation was significantly higher pre-electronic health record than post electronic health record and percent of medication reconciliation completion was significantly lower pre--electronic health record than post electronic health record and percent of medication reconciliation completion was significantly higher pre

  10. Gravitational waves from a supercooled electroweak phase transition and their detection with pulsar timing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kobakhidze, Archil; Lagger, Cyril; Manning, Adrian [University of Sydney, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Sydney, NSW (Australia); Yue, Jason [National Taiwan Normal University, Department of Physics, Taipei (China)

    2017-08-15

    We investigate the properties of a stochastic gravitational wave background produced by a first-order electroweak phase transition in the regime of extreme supercooling. We study a scenario whereby the percolation temperature that signifies the completion of the transition, T{sub p}, is as low as a few MeV (nucleosynthesis temperature), while most of the true vacuum bubbles are formed much earlier at the nucleation temperature, T{sub n} ∝ 50 GeV. This implies that the gravitational wave spectrum is mainly produced by the collisions of large bubbles and characterised by a large amplitude and a peak frequency as low as f ∝ 10{sup -9}-10{sup -7} Hz. We show that such a scenario can occur in (but not limited to) a model based on a non-linear realisation of the electroweak gauge group, so that the Higgs vacuum configuration is altered by a cubic coupling. In order to carefully quantify the evolution of the phase transition of this model over such a wide temperature range we go beyond the usual fast transition approximation, taking into account the expansion of the Universe as well as the behaviour of the nucleation probability at low temperatures. Our computation shows that there exists a range of parameters for which the gravitational wave spectrum lies at the edge between the exclusion limits of current pulsar timing array experiments and the detection band of the future Square Kilometre Array observatory. (orig.)

  11. Dynamic phase transitions in a cylindrical Ising nanowire under a time-dependent oscillating magnetic field

    International Nuclear Information System (INIS)

    Deviren, Bayram; Kantar, Ersin; Keskin, Mustafa

    2012-01-01

    The dynamic phase transitions in a cylindrical Ising nanowire system under a time-dependent oscillating external magnetic field for both ferromagnetic and antiferromagnetic interactions are investigated within the effective-field theory with correlations and the Glauber-type stochastic dynamics approach. The effective-field dynamic equations for the average longitudinal magnetizations on the surface shell and core are derived by employing the Glauber transition rates. Temperature dependence of the dynamic magnetizations, the dynamic total magnetization, the hysteresis loop areas and the dynamic correlations are investigated in order to characterize the nature (first- or second-order) of the dynamic transitions as well as the dynamic phase transition temperatures and the compensation behaviors. The system strongly affected by the surface situations. Some characteristic phenomena are found depending on the ratio of the physical parameters in the surface shell and the core. According to the values of Hamiltonian parameters, five different types of compensation behaviors in the Néel classification nomenclature exist in the system. The system also exhibits a reentrant behavior. - Highlights: ► The dynamic aspects of a cylindrical Ising nanowire are investigated in detail. ► The dynamic magnetizations, hysteresis loop areas and correlations are calculated. ► We studied both the FM and AFM interactions within the EFT with correlations. ► Some characteristic phenomena are found depending on the interaction parameters. ► We obtained five different types of compensation behaviors and reentrant behavior.

  12. Dynamic phase transitions in a cylindrical Ising nanowire under a time-dependent oscillating magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Deviren, Bayram [Department of Physics, Nevsehir University, 50300 Nevsehir (Turkey); Kantar, Ersin [Department of Physics, Erciyes University, 38039 Kayseri (Turkey); Keskin, Mustafa, E-mail: keskin@erciyes.edu.tr [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)

    2012-07-15

    The dynamic phase transitions in a cylindrical Ising nanowire system under a time-dependent oscillating external magnetic field for both ferromagnetic and antiferromagnetic interactions are investigated within the effective-field theory with correlations and the Glauber-type stochastic dynamics approach. The effective-field dynamic equations for the average longitudinal magnetizations on the surface shell and core are derived by employing the Glauber transition rates. Temperature dependence of the dynamic magnetizations, the dynamic total magnetization, the hysteresis loop areas and the dynamic correlations are investigated in order to characterize the nature (first- or second-order) of the dynamic transitions as well as the dynamic phase transition temperatures and the compensation behaviors. The system strongly affected by the surface situations. Some characteristic phenomena are found depending on the ratio of the physical parameters in the surface shell and the core. According to the values of Hamiltonian parameters, five different types of compensation behaviors in the Neel classification nomenclature exist in the system. The system also exhibits a reentrant behavior. - Highlights: Black-Right-Pointing-Pointer The dynamic aspects of a cylindrical Ising nanowire are investigated in detail. Black-Right-Pointing-Pointer The dynamic magnetizations, hysteresis loop areas and correlations are calculated. Black-Right-Pointing-Pointer We studied both the FM and AFM interactions within the EFT with correlations. Black-Right-Pointing-Pointer Some characteristic phenomena are found depending on the interaction parameters. Black-Right-Pointing-Pointer We obtained five different types of compensation behaviors and reentrant behavior.

  13. Properties of transit-time interactions in magnetized plasmas: Analytic and numerical results

    International Nuclear Information System (INIS)

    Melatos, A.; Robinson, P.A.

    1993-01-01

    The recently developed perturbation theory of transit-time interactions between particles and coherent wave packets in magnetized plasmas is applied to particular field structures. Limits of validity are determined by comparison with test-particle simulations, showing that the theory is accurate everywhere except near certain well-determined resonances, for wave fields exceeding a characteristic threshold, and for particles below a particular velocity. The properties of transit-time interactions in magnetized plasmas are investigated in detail to determine their dependence on the fields and parameters of the particle motion. Resonant particle scattering is found to occur at low particle velocities when the frequency of the coherent wave packet is an integer multiple of the gyrofrequency. Two different types of resonant transit-time dissipation are also observed: one arises from transient cyclotron acceleration in the localized wave packet, the other from beating between the gyration of the particles and the oscillation of the wave packet field. Both effects involve an interplay between the field geometry and resonant oscillations

  14. Insights into the photochemical disproportionation of transition metal dimers on the picosecond time scale.

    Science.gov (United States)

    Lomont, Justin P; Nguyen, Son C; Harris, Charles B

    2013-05-09

    The reactivity of five transition metal dimers toward photochemical, in-solvent-cage disproportionation has been investigated using picosecond time-resolved infrared spectroscopy. Previous ultrafast studies on [CpW(CO)3]2 established the role of an in-cage disproportionation mechanism involving electron transfer between 17- and 19-electron radicals prior to diffusion out of the solvent cage. New results from time-resolved infrared studies reveal that the identity of the transition metal complex dictates whether the in-cage disproportionation mechanism can take place, as well as the more fundamental issue of whether 19-electron intermediates are able to form on the picosecond time scale. Significantly, the in-cage disproportionation mechanism observed previously for the tungsten dimer does not characterize the reactivity of four out of the five transition metal dimers in this study. The differences in the ability to form 19-electron intermediates are interpreted either in terms of differences in the 17/19-electron equilibrium or of differences in an energetic barrier to associative coordination of a Lewis base, whereas the case for the in-cage vs diffusive disproportionation mechanisms depends on whether the 19-electron reducing agent is genuinely characterized by 19-electron configuration at the metal center or if it is better described as an 18 + δ complex. These results help to better understand the factors that dictate mechanisms of radical disproportionation and carry implications for radical chain mechanisms.

  15. The acceleration of energetic particles in the interplanetary medium by transit time damping

    International Nuclear Information System (INIS)

    Fisk, L.A.

    1976-01-01

    It has been reported recently by McDonald et al. (1976) that 1-MeV protons may undergo considerable acceleration in corotating streams. It has been suggested recently by Fisk et al. (1974b) that interstellar neutral particles which are ionized in the solar cavity may be accelerated in the solar wind and may account for the anomalous component that is observed in low-energy cosmic rays (at approx.10 MeV/nucleon). It is shown here that the particles in both of these cases could be accelerated by transit time damping propagating fluctuations in the magnitude of the interplanetary magnetic field (e.g., magnetosonic waves). The protons in corotating streams may be accelerated by transit time damping the small-scale variations in the field magnitude that are observed at a low level in the inner solar system. The interstellar ions may be accelerated by transit time damping large-scale field variations in the outer solar system

  16. A Framework for Relating Timed Transition Systems and Preserving TCTL Model Checking

    DEFF Research Database (Denmark)

    Jacobsen, Lasse; Jacobsen, Morten; Møller, Mikael Harkjær

    2010-01-01

    Many formal translations between time dependent models have been proposed over the years. While some of them produce timed bisimilar models, others preserve only reachability or (weak) trace equivalence. We suggest a general framework for arguing when a translation preserves Timed Computation Tree...... Logic (TCTL) or its safety fragment.The framework works at the level of timed transition systems, making it independent of the modeling formalisms and applicable to many of the translations published in the literature. Finally, we present a novel translation from extended Timed-Arc Petri Nets...... to Networks of Timed Automata and using the framework argue that itpreserves the full TCTL. The translation has been implemented in the verification tool TAPAAL....

  17. GIS-measured walkability, transit, and recreation environments in relation to older Adults' physical activity: A latent profile analysis.

    Science.gov (United States)

    Todd, Michael; Adams, Marc A; Kurka, Jonathan; Conway, Terry L; Cain, Kelli L; Buman, Matthew P; Frank, Lawrence D; Sallis, James F; King, Abby C

    2016-12-01

    An infrequently studied question is how diverse combinations of built environment (BE) features relate to physical activity (PA) for older adults. We derived patterns of geographic information systems- (GIS) measured BE features and explored how they accounted for differences in objective and self-reported PA, sedentary time, and BMI in a sample of older adults. Senior Neighborhood Quality of Life Study participants (N=714, aged 66-97years, 52.1% women, 29.7% racial/ethnic minority) were sampled in 2005-2008 from the Seattle-King County, WA and Baltimore, MD-Washington, DC regions. Participants' home addresses were geocoded, and net residential density, land use mix, retail floor area ratio, intersection density, public transit density, and public park and private recreation facility density measures for 1-km network buffers were derived. Latent profile analyses (LPAs) were estimated from these GIS-based measures. In multilevel regression models, profiles were compared on accelerometer-measured moderate-to-vigorous PA (MVPA) and sedentary time and self-reported PA, adjusting for covariates and clustering. Analyses were conducted in 2014-2015. LPAs yielded three profiles: low walkability/transit/recreation (L-L-L); mean walkability/transit/recreation (M-M-M); and high walkability/transit/recreation (H-H-H). Three PA outcomes were more favorable in the HHH than the LLL profile group (difference of 7.2min/day for MVPA, 97.8min/week for walking for errands, and 79.2min/week for walking for exercise; all pswalkability index, suggesting that diverse BE features are important for healthy aging. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Buttafava, Mauro, E-mail: mauro.buttafava@polimi.it; Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Dalla Mora, Alberto [Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy)

    2014-08-15

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor.

  19. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    International Nuclear Information System (INIS)

    Buttafava, Mauro; Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto; Dalla Mora, Alberto

    2014-01-01

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor

  20. Dead time effects in laser Doppler anemometry measurements

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Buchhave, Preben; George, William K.

    2014-01-01

    frequency range, starting around the cutoff frequency due to the finite size of the MV. Using computer-generated data mimicking the LDA data, these effects have previously been shown to appear due to the effect of dead time, i.e., the finite time during which the system is not able to acquire new...... measurements. These dead times can be traced back to the fact that the burst-mode LDA cannot measure more than one signal burst at a time. Since the dead time is approximately equal to the residence time for a particle traversing a measurement volume, we are dealing with widely varying dead times, which...

  1. Measurement of Sub-Picosecond Electron Bunches via Electro-Optic Sampling of Coherent Transition Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Timothy John [Northern Illinois U.

    2012-01-01

    Future collider applications as well as present high-gradient laser plasma wakefield accelerators and free-electron lasers operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. We present results on the single-shot electro-optic spectral decoding of coherent transition radiation from bunches generated at the Fermilab A0 photoinjector laboratory. A longitudinal double-pulse modulation of the electron beam is also realized by transverse beam masking followed by a transverse-to-longitudinal phase-space exchange beamline. Live profile tuning is demonstrated by upstream beam focusing in conjunction with downstream monitoring of single-shot electro-optic spectral decoding of the coherent transition radiation.

  2. The IPERMOB System for Effective Real-Time Road Travel Time Measurement and Prediction

    OpenAIRE

    Martelli, Francesca; Renda, Maria Elena; Santi, Paolo

    2010-01-01

    Accurate, real-time measurement and estimation of road travel time is considered a central problem in the design of advanced Intelligent Transportation Systems. In particular, whether eective, real-time collection of travel time measurements in a urban area is possible is, to the best of our knowledge, still an open problem. In this paper, we introduce the IPERMOB system for efficient, real-time collection of travel time measurements in urban areas through vehicular networks. We demonstrate t...

  3. Femtosecond Near Edge X-ray Absorption Measurement of the VO2 Phase Transition

    International Nuclear Information System (INIS)

    Cavalleri, A.; Chong, H.H.W.; Fourmaux, S.; Glover, T.E.; Heimann, P.A; Kieffer, J.C.; Padmore, H.A.; Schoenlein, R.W.

    2004-01-01

    The authors measure the insulator-to-metal transition in VO 2 using femtosecond Near-Edge X-ray Absorption. Sliced pulses of synchrotron radiation are used to detect the photo-induced dynamics at the 516-eV Vanadium L 3 edge

  4. Effects of skin pressure by clothing on digestion and orocecal transit time of food.

    Science.gov (United States)

    Sone, Y; Kato, N; Kojima, Y; Takasu, N; Tokura, H

    2000-05-01

    In order to reveal the influence of clothing skin pressure on digestion of food through the gastrointestinal tract, we examined the absorption of dietary carbohydrate and orocecal transit time of a test meal by means of a breath hydrogen test on 7 healthy young women. In this experiment, we collected breath samples from the participants wearing loose-fitting experimental garment on the second day of the experiment and from the same participants but wearing an additional tight-fitting girdle on the following day for 16 hours and 9 hours, respectively. Skin pressure applied by a girdle on participant's waist, abdomen and hip region was 15.5 +/- 0.4 mmHg (mean +/- SE), 11.0 +/- 0.2 mmHg, and 13.6 +/- 0.6 mmHg, respectively, and the values were 2-3 times larger than those of the experimental garment. The hydrogen concentration vs. time curve showed that breath hydrogen levels at its peaks (15:00, 15:30, 16:00, 16:30, and 17:00 hr) on the third day of the experiment were significantly higher than those of the corresponding time on the second day (p clothing condition (p hand, the transit time of the test meal for the subjects wearing a girdle did not differ significantly from that for the subjects wearing the garment of less pressure (270 +/- 18 minutes and 263 +/- 21 minutes, respectively). These results indicate that the clothing skin pressure has an inhibitory effect on the absorption of dietary carbohydrate in the small intestine, but no effect on the orocecal transit time of a meal.

  5. Picosecond time measurement using ultra fast analog memories

    OpenAIRE

    Breton, D.; Delagnes, E.; Maalmi, J.

    2009-01-01

    International audience; The currently existing electronics dedicated to precise time measurement is mainly based on the use of constant fraction discriminators (CFD) associated with Time to Digital Converters (TDC). The constant fraction technique minimizes the time walk effect (dependency of timing on the pulse amplitude). Several attempts have been made to integrate CFD in multi-channel ASICs. But the time resolution measured on the most advanced one is of the order of 30 ps rms. Two main t...

  6. Contrast fluoroscopic evaluation of gastrointestinal transit times with and without the use of falconry hoods in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Doss, Grayson A; Williams, Jackie M; Mans, Christoph

    2017-11-01

    OBJECTIVE To evaluate gastrointestinal transit times in red-tailed hawks (Buteo jamaicensis) by use of contrast fluoroscopic imaging and investigate the effect of falconry hooding in these hawks on gastrointestinal transit time. DESIGN Prospective, randomized, blinded, complete crossover study. ANIMALS 9 healthy red-tailed hawks. PROCEDURES Hawks were gavage-fed a 30% weight-by-volume barium suspension (25 mL/kg [11.3 mL/lb]) into the crop. Fluoroscopic images were obtained at multiple time points after barium administration. Time to filling and emptying of various gastrointestinal tract organs and overall transit time were measured. The effect of hooding (hooded vs nonhooded) on these variables was assessed in a randomized complete crossover design. RESULTS In nonhooded birds, overall gastrointestinal transit time ranged from 30 to 180 minutes (mean ± SD, 100 ± 52 min). Time to complete crop emptying ranged from 30 to 180 minutes (83 ± 49 min). Contrast medium was present in the ventriculus in all birds within 5 minutes of administration and in the small intestines within 5 to 15 minutes (median, 5 min). Hooding of red-tailed hawks resulted in a significant delay of complete crop emptying (no hood, 83 ± 49 minutes; hood, 133 ± 48 minutes), but no significant effects of hooding were found on other measured variables. CONCLUSIONS AND CLINICAL RELEVANCE These results indicated that overall gastrointestinal transit times are faster in red-tailed hawks than has been reported for psittacines and that the use of a falconry hood in red-tailed hawks may result in delayed crop emptying. Hooding did not exert significant effects on overall gastrointestinal transit time in this raptorial species.

  7. Colon Transit Time Test in Korean Children with Chronic Functional Constipation

    Science.gov (United States)

    Yoo, Ha Yeong; Kim, Mock Ryeon; Park, Hye Won; Son, Jae Sung

    2016-01-01

    Purpose Each ethnic group has a unique life style, including diets. Life style affects bowel movement. The aim of this study is to describe the results of colon transit time (CTT) tests in Korean children who had chronic functional constipation based on highly refined data. Methods One hundred ninety (86 males) out of 415 children who performed a CTT test under the diagnosis of chronic constipation according to Rome III criteria at Konkuk University Medical Center from January 2006 through March 2015 were enrolled in this study. Two hundreds twenty-five children were excluded on the basis of CTT test result, defecation diary, and clinical setting. Shapiro-Wilk and Mann-Whitney U, and chi-square tests were used for statistical analysis. Results The median value and interquartile range (IQR) of CTT was 54 (37.5) hours in Encopresis group, and those in non-encopresis group was 40.2 (27.9) hours (pencopresis group and encopresis was statistically significant (p=0.002). The non-encopresis group (n=154, 81.1%) was divided into normal transit subgroup (n=84, 54.5%; median value and IQR of CTT=26.4 [9.6] hours), outlet obstruction subgroup (n=18, 11.7%; 62.4 [15.6] hours), and slow transit subgroup (n=52, 33.8%; 54.6 [21.0] hours]. The encopresis group (n=36, 18.9%) was divided into normal transit subgroup (n=8, 22.2%; median value and IQR of CTT=32.4 [9.9] hours), outlet obstruction subgroup (n=8, 22.2%; 67.8 [34.8] hours), and slow transit subgroup (n=20, 55.6%; 59.4 [62.7]hours). Conclusion This study provided the basic pattern and value of the CTT test in Korean children with chronic constipation. PMID:27064388

  8. ISOL yield predictions from holdup-time measurements

    International Nuclear Information System (INIS)

    Spejewski, Eugene H.; Carter, H Kennon; Mervin, Brenden T.; Prettyman, Emily S.; Kronenberg, Andreas; Stracener, Daniel W

    2008-01-01

    A formalism based on a simple model is derived to predict ISOL yields for all isotopes of a given element based on a holdup-time measurement of a single isotope of that element. Model predictions, based on parameters obtained from holdup-time measurements, are compared to independently-measured experimental values

  9. Time-dependent Hartree-Fock dynamics and phase transition in Lipkin-Meshkov-Glick model

    International Nuclear Information System (INIS)

    Kan, K.; Lichtner, P.C.; Dworzecka, M.; Griffin, J.J.

    1980-01-01

    The time-dependent Hartree-Fock solutions of the two-level Lipkin-Meshkov-Glick model are studied by transforming the time-dependent Hartree-Fock equations into Hamilton's canonical form and analyzing the qualitative structure of the Hartree-Fock energy surface in the phase space. It is shown that as the interaction strength increases these time-dependent Hartree-Fock solutions undergo a qualitative change associated with the ground state phase transition previously studied in terms of coherent states. For two-body interactions stronger than the critical value, two types of time-dependent Hartree-Fock solutions (the ''librations'' and ''rotations'' in Hamilton's mechanics) exist simultaneously, while for weaker interactions only the rotations persist. It is also shown that the coherent states with the maximum total pseudospin value are determinants, so that time-dependent Hartree-Fock analysis is equivalent to the coherent state method

  10. A new methodology for measuring time correlations and excite states of atoms and nuclei

    International Nuclear Information System (INIS)

    Cavalcante, M.A.

    1989-01-01

    A system for measuring time correlation of physical phenomena events in the range of 10 -7 to 10 5 sec is proposed, and his results presented. This system, is based on a sequential time scale which is controlled by a precision quartz oscillator; the zero time of observation is set by means of a JK Flip-Flop, which is operated by a negative transition of pulse in coincidence with the pulse from a detector which marks the time zero of the event (precedent pulse). This electronic system (named digital chronoanalizer) was used in the measurement of excited states of nuclei as well as for the determination of time fluctuations in physical phenomena, such as the time lag in a halogen Geiger counter and is the measurement of the 60 KeV excited state of N P 237 . (author)

  11. SHORT COMMUNICATION: Time measurement device with four femtosecond stability

    Science.gov (United States)

    Panek, Petr; Prochazka, Ivan; Kodet, Jan

    2010-10-01

    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.

  12. VizieR Online Data Catalog: Times of transits and occultations of WASP-12b (Patra+, 2017)

    Science.gov (United States)

    Patra, K. C.; Winn, J. N.; Holman, M. J.; Yu, L.; Deming, D.; Dai, F.

    2017-08-01

    Between 2016 October and 2017 February, we observed seven transits of WASP-12 with the 1.2m telescope at the Fred Lawrence Whipple Observatory on Mt. Hopkins, Arizona. Images were obtained with the KeplerCam detector through a Sloan r'-band filter. The typical exposure time was 15s, chosen to give a signal-to-noise ratio of about 200 for WASP-12. The field of view of this camera is 23.1' on a side. We used 2*2 binning, giving a pixel scale of 0.68''. We measured two new occultation times based on hitherto unpublished Spitzer observations in 2013 December (program 90186, P.I. Todorov). Two different transits were observed, one at 3.6μm and one at 4.5μm. The data take the form of a time series of 32*32-pixel subarray images, with an exposure time of 2.0s per image. The data were acquired over a wide range of orbital phases, but for our purpose, we analyzed only the ~14000 images within 4hr of each occultation. (1 data file).

  13. Hidden measurements, hidden variables and the volume representation of transition probabilities

    OpenAIRE

    Oliynyk, Todd A.

    2005-01-01

    We construct, for any finite dimension $n$, a new hidden measurement model for quantum mechanics based on representing quantum transition probabilities by the volume of regions in projective Hilbert space. For $n=2$ our model is equivalent to the Aerts sphere model and serves as a generalization of it for dimensions $n \\geq 3$. We also show how to construct a hidden variables scheme based on hidden measurements and we discuss how joint distributions arise in our hidden variables scheme and th...

  14. The Hetu'u Global Network: Measuring the Distance to the Sun with the Transit of Venus

    Science.gov (United States)

    Rodriguez, David; Faherty, J.

    2013-01-01

    In the spirit of historic astronomical endeavors, we invited school groups across the globe to collaborate in a solar distance measurement using the 2012 transit of Venus. In total, our group (stationed at Easter Island, Chile) recruited 19 school groups spread over 6 continents and 10 countries to participate in our Hetu’u Global Network. Applying the methods of French astronomer Joseph-Nicolas Delisle, we used individual second and third Venus-Sun contact times to calculate the distance to the Sun. Ten of the sites in our network had amiable weather; 8 of which measured second contact and 5 of which measured third contact leading to consistent solar distance measurements of 152+/-30 million km and 163+/-30 million km respectively. The distance to the Sun at the time of the transit was 152.25 million km; therefore, our measurements are also consistent within 1-sigma of the known value. The goal of our international school group network was to inspire the next generation of scientists using the excitement and accessibility of such a rare astronomical event. In the process, we connected hundreds of participating students representing a diverse, multi-cultural group with differing political, economic, and racial backgrounds.

  15. Mean transit times as a parameter for optimizing the quantitative brain scintigraphy

    International Nuclear Information System (INIS)

    Vosberg, H.; Szabo, Z.; Nase, D.; Feinendegen, L.E.

    1984-01-01

    Cerebral perfusion imaging with non-diffusible Tc-9mm-labelled substances is a simple screening procedure for identifying perfusion deficits, which can easily be applied in all nuclear medicine departments. Gross hypoperfusion can readily be recognized on analog images. To visualize and assess minor changes in limited brain areas, the perfusion phase in each pixel was fitted to a gamma function and the mean transit times were stored as parametric matrix. To examine the diagnostic sensitivity of transit time images versus that of the usual semiquantitative procedures, data of 84 patients with unilateral cerebral blood flow disorders were analyzed. From the pertinent studies parameters of hemispheral flow were computed using 10 different methodes. Data for the normal and the diseased hemisphere and their ratios were subjected to analysis of variance to assess their diagnostic weight. Patient groups with different angiologically verfied stenoses or occlusion were most easily dinstinguished by the time interval carotid artery - hemispheral peak. The values derived from the parametric images of mean transit times showed more or less the same weight, but the special advantage offered by parametric images, i.e. the precise visualization of the hypoperfused area, was not considered in the analysis of variance. Factorial analysis indicated that the parameters examined can be described by 2 factors to the extent of 72%. The first of these factors combines the weights (58%) of those variables which, in one may or the other, reflect the time of perfusion, while the second includes variables which make use of the count rates for differentiation (14%). The analysis of gamma camera data for diagnosing cerebral blood flow disorders is thus improved. (Author)

  16. Television viewing, leisure-time exercise and acute coronary syndrome in transitional Albania.

    Science.gov (United States)

    Burazeri, Genc; Goda, Artan; Kark, Jeremy D

    2008-07-01

    To assess the association of leisure-time exercise and television (TV) viewing, a sedentary marker, with acute coronary syndrome (ACS) in Albania, a transitional country in Southeast Europe. A population-based case-control study was conducted among Tirana residents in 2003-2006. Information on leisure-time exercise (transformed into kilocalories of energy expenditure) and daily hours of TV viewing was obtained by interviewer-administered questionnaire. 460 non-fatal ACS patients (368 men, 92 women) and 628 coronary heart disease-free controls (413 men, 215 women) were studied. Adjusted for socio-demographic characteristics, conventional coronary risk factors and leisure-time exercise, TV viewing was associated with ACS in women (OR=1.66, 95%CI=1.12-2.46 per hour/day viewing), but not in men (OR=0.93, 95%CI=0.81-1.07; P for sex-interaction=0.02). A low level of leisure-time exercise (adjusted also for TV viewing) was associated with ACS similarly in men and women (pooled sexes OR=2.03, 95%CI=1.29-3.22 for bottom vs top tertile of energy expenditure). Leisure-time inactivity is confirmed as an important risk factor for ACS also in Southeastern Europe. TV viewing may be an informative coronary risk marker in transitional societies, especially in women.

  17. Identifying timescales and possible precursors of the awake to asleep transition in EOG time series

    International Nuclear Information System (INIS)

    Carniel, Roberto; Del Pin, Enrico; Budai, Riccardo; Pascolo, Paolo

    2005-01-01

    In this work we study the awake to asleep state transition in eye blinking activity. In this perspective the human electroculographic activity (EOG) was first experimentally investigated by means of a spectral analyses of the time series resulting for processes underlying both the brain activity and the eye dynamics. We studied the evolution of the spectral content both via the classical spectrogram and with the computation of summarizing scalar parameters: mean frequency, maximum frequency, spectral variance. With these tools we highlighted a significative dynamical change appearing before the transition from the awake to the asleep state, characterized by a general widening of the spectrum, that translates into a decrease of the maximum frequency, an increase of the average frequency and an increase of the spectral variance. Due to inherently high non-linearities involved, chaotic patterns were likely to occur in the experimental time series. These were analyzed therefore with the chaos theory. In particular we studied the time evolution of dynamical parameters as computed on different windows of the time series, i.e. optimal delay time as suggested by autocorrelation and mutual information on one side, embedding quality evaluation as suggested by the False Nearest Neighbours percentage on the other

  18. Material Classification Using Raw Time-of-Flight Measurements

    KAUST Repository

    Su, Shuochen; Heide, Felix; Swanson, Robin J.; Klein, Jonathan; Callenberg, Clara; Hullin, Matthias; Heidrich, Wolfgang

    2016-01-01

    We propose a material classification method using raw time-of-flight (ToF) measurements. ToF cameras capture the correlation between a reference signal and the temporal response of material to incident illumination. Such measurements encode unique

  19. Influence of Sensor Ingestion Timing on Consistency of Temperature Measures

    National Research Council Canada - National Science Library

    Goodman, Daniel A; Kenefick, Robert W; Cadarette, Bruce S; Cheuvront, Samuel N

    2009-01-01

    ... (ITS) to measure core body temperature have been demonstrated. However, the effect of elapsed time between ITS ingestion and Tint measurement has not been thoroughly studied. Methods: Eight volunteers...

  20. Correlations between aorto-popliteal bolus transit speed and aortic and popliteal bolus transit time during CT angiography of aortoiliac and lower extremity arteries

    Energy Technology Data Exchange (ETDEWEB)

    Nakaya, Yasuhiro, E-mail: y-nakaya@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka 565-0871 (Japan); Kim, Tonsok; Hori, Masatoshi; Onishi, Hiromitsu; Nakamoto, Atsushi; Tsuboyama, Takahiro; Maeda, Noboru; Higashihara, Hiroki; Tomoda, Kaname; Nakamura, Hironobu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka 565-0871 (Japan)

    2011-08-15

    Purpose: The purpose of this study was to investigate correlations between the aorto-popliteal bolus transit speed and aortic and popliteal bolus transit time in order to evaluate the possibility for prediction of bolus transit speed by single test injection technique. Materials and methods: Approval was obtained from our institutional review board for this study, which included 42 patients, from all of whom written informed consent was obtained. Low-dose serial CT scanning after injection of 12 ml contrast material (300 mg/ml) at a rate of 3 ml/s followed by saline flush was performed twice, first at the level of the upper abdomen and second at the level of the knee joint. The times needed to reach peak enhancement of the upper abdominal aorta (T-aorta) and bilateral popliteal arteries (T-popliteal) were obtained, and aorto-popliteal bolus transit speeds between the abdominal aorta and popliteal arteries were calculated. ABI was recorded for the bilateral feet. The Pearson's product-moment correlation coefficient was used to investigate the correlation between the bolus transit speed and T-aorta, T-popliteal, ABI, and patient age. Result: The respective correlation coefficients for bolus transit speed on the one hand and T-aorta, T-popliteal, ABI, patient age on the other were -0.50, -0.84, 0.36, and -0.52. Conclusion: The time to peak enhancement for popliteal arteries showed the strongest correlation with aorto-popliteal bolus transit speeds, and was considered to be the most accurate predictor for aorto-popliteal bolus transit speeds.

  1. Does timing and sequencing of transitions to adulthood make a difference? Stress, smoking, and physical activity among young Australian women.

    Science.gov (United States)

    Bell, Sandra; Lee, Christina

    2006-01-01

    The major changes of the transition to adulthood are argued to be stressful, and health-related behaviors such as smoking and physical activity may be adopted, consolidated, or abandoned at this time. On the other hand, research has suggested that the normative transitions of emerging adulthood, although involving considerable change, may be associated with low stress because they are perceived as both positive and normal at this life stage. This article examines relations between the timing and sequencing of life transitions and stress and health-related behaviors, focusing on the transition to young adulthood among Australian women. A total of 853 women aged 22 to 27 provided information about the timing and sequencing of 6 life transitions: moving out of home, stopping full-time education, starting full-time work, having the first live-in relationship, marriage, and motherhood-and stress, smoking, and physical activity. Most had moved out of home, stopped full-time education, and started full-time work, but only 14% had undertaken all 6 transitions. Overall, 70% of participants had made transitions "in order." Overall, the findings suggest that the relations between timing and sequencing of transitions, and indicators of health, are moderate for smoking, but small for stress and for physical activity. These effects remained after controlling for socioeconomic status of the participants' families of origin. Matching current social norms for the timing and sequencing of life changes may be of less importance for women's well-being than is commonly believed. Although the significant relations between early or "out of order" transitions and smoking are of concern, the smaller relations with stress and with sedentariness suggest that such transitions may have limited negative consequences, and support the view that individuals are active in choosing the life path that is appropriate for them and their circumstances.

  2. Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction

    Science.gov (United States)

    Cailleau, Hervé Collet, Eric; Buron-Le Cointe, Marylise; Lemée-Cailleau, Marie-Hélène Koshihara, Shin-Ya

    A new frontier in the field of structural science is the emergence of the fast and ultra-fast X-ray science. Recent developments in time-resolved X-ray diffraction promise direct access to the dynamics of electronic, atomic and molecular motions in condensed matter triggered by a pulsed laser irradiation, i.e. to record "molecular movies" during the transformation of matter initiated by light pulse. These laser pump and X-ray probe techniques now provide an outstanding opportunity for the direct observation of a photoinduced structural phase transition as it takes place. The use of X-ray short-pulse of about 100ps around third-generation synchrotron sources allows structural investigations of fast photoinduced processes. Other new X-ray sources, such as laser-produced plasma ones, generate ultra-short pulses down to 100 fs. This opens the way to femtosecond X-ray crystallography, but with rather low X-ray intensities and more limited experimental possibilities at present. However this new ultra-fast science rapidly progresses around these sources and new large-scale projects exist. It is the aim of this contribution to overview the state of art and the perspectives of fast and ultra-fast X-ray scattering techniques to study photoinduced phase transitions (here, the word ultra-fast is used for sub-picosecond time resolution). In particular we would like to largely present the contribution of crystallographic methods in comparison with optical methods, such as pump-probe reflectivity measurements, the reader being not necessary familiar with X-ray scattering. Thus we want to present which type of physical information can be obtained from the positions of the Bragg peaks, their intensity and their shape, as well as from the diffuse scattering beyond Bragg peaks. An important physical feature is to take into consideration the difference in nature between a photoinduced phase transition and conventional homogeneous photoinduced chemical or biochemical processes where

  3. A Fourier Collocation Approach for Transit-Time Ultrasonic Flowmeter Under Multi-Phase Flow Conditions

    DEFF Research Database (Denmark)

    Simurda, Matej; Lassen, Benny; Duggen, Lars

    2017-01-01

    A numerical model for a clamp-on transit-time ultrasonic flowmeter (TTUF) under multi-phase flow conditions is presented. The method solves equations of linear elasticity for isotropic heterogeneous materials with background flow where acoustic media are modeled by setting shear modulus to zero....... Spatial derivatives are calculated by a Fourier collocation method allowing the use of the fast Fourier transform (FFT) and time derivatives are approximated by a finite difference (FD) scheme. This approach is sometimes referred to as a pseudospectral time-domain method. Perfectly matched layers (PML......) are used to avoid wave-wrapping and staggered grids are implemented to improve stability and efficiency. The method is verified against exact analytical solutions and the effect of the time-staggering and associated lowest number of points per minimum wavelengths value is discussed. The method...

  4. Comparable Measures of Accessibility to Public Transport Using the General Transit Feed Specification

    Directory of Open Access Journals (Sweden)

    Jinjoo Bok

    2016-03-01

    Full Text Available Public transport plays a critical role in the sustainability of urban settings. The mass mobility and quality of urban lives can be improved by establishing public transport networks that are accessible to pedestrians within a reasonable walking distance. Accessibility to public transport is characterized by the ease with which inhabitants can reach means of transportation such as buses or metros. By measuring the degree of accessibility to public transport networks using a common data format, a comparative study can be conducted between different cities or metropolitan areas with different public transit systems. The General Transit Feed Specification (GTFS by Google Developers allows this by offering a common format based on text files and sharing the data set voluntarily produced and contributed by the public transit agencies of many participating cities around the world. This paper suggests a method to assess and compare public transit accessibility in different urban areas using the GTFS feed and demographic data. To demonstrate the value of the new method, six examples of metropolitan areas and their public transit accessibility are presented and compared.

  5. Period, epoch, and prediction errors of ephemerides from continuous sets of timing measurements

    Science.gov (United States)

    Deeg, H. J.

    2015-06-01

    Space missions such as Kepler and CoRoT have led to large numbers of eclipse or transit measurements in nearly continuous time series. This paper shows how to obtain the period error in such measurements from a basic linear least-squares fit, and how to correctly derive the timing error in the prediction of future transit or eclipse events. Assuming strict periodicity, a formula for the period error of these time series is derived, σP = σT (12 / (N3-N))1 / 2, where σP is the period error, σT the timing error of a single measurement, and N the number of measurements. Compared to the iterative method for period error estimation by Mighell & Plavchan (2013), this much simpler formula leads to smaller period errors, whose correctness has been verified through simulations. For the prediction of times of future periodic events, usual linear ephemeris were epoch errors are quoted for the first time measurement, are prone to an overestimation of the error of that prediction. This may be avoided by a correction for the duration of the time series. An alternative is the derivation of ephemerides whose reference epoch and epoch error are given for the centre of the time series. For long continuous or near-continuous time series whose acquisition is completed, such central epochs should be the preferred way for the quotation of linear ephemerides. While this work was motivated from the analysis of eclipse timing measures in space-based light curves, it should be applicable to any other problem with an uninterrupted sequence of discrete timings for which the determination of a zero point, of a constant period and of the associated errors is needed.

  6. Effect of counting system dead time on thyroid uptake measurements

    International Nuclear Information System (INIS)

    Simpkin, D.J.

    1984-01-01

    Equations are derived and the results of numerical calculations shown that illustrate the effect of counting system dead time on measured thyroid uptake of radioiodine. It is predicted that the observed uptake is higher than the true uptake due to system dead time. This is shown for both paralyzing and nonparalyzing dead time. The effect of increasing the administered activity is shown to increase the measured uptake, in a manner predicted by the paralyzable and nonparalyzable dead time models

  7. Detection of Second Order Melting Transitions in the HTSC's by Specific Heat Measurements?

    Science.gov (United States)

    Pierson, Stephen W.; Valls, Oriol T.

    1997-03-01

    The finite magnetic field phase transition in the high-temperature superconductors from the solid vortex lattice to the liquid has been under intense study recently. Detection of this melting is difficult but has been seen in magnetization and resistivity measurements. It has also been reported recently in specific heat measurements. In particular, in one case, evidence for a second order melting phase transition has been presented based on specific heat measurements.(M. Roulin, A. Junod, and E. Walker. Science 273), 1210 (1996). However, we present evidence that the feature in the specific heat data can be explained using a theory derived using the lowest-Landau-level approximation(Z. Tes)anović and A. V. Andreev, Phys. Rev. B 49, 4064 (1994) that does not invoke flux lattice melting arguments.

  8. Analysis of thermal fluctuations in the semiscale tests to determine flow transit delay times using a transfer function cross-correlation technique

    International Nuclear Information System (INIS)

    Raptis, A.C.; Popper, G.F.

    1977-08-01

    On April 14, 1976, EG and G performed the Semiscale Blowdown 29-1 experiment to try to establish the feasibility of using a transit time flowmeter (TTF) to measure transient blowdown two-phase flow rates. The recorded signals from that experiment were made available to and analyzed by the Argonne National Laboratory using the transfer function cross-correlation technique. The theoretical background for the transfer function method of analysis and the results of the data analysis are presented. Histograms of transit time during the blowdown are shown and topics for further investigation are identified

  9. High-effective position time spectrometer in actual measurements of low intensity region of electron spectra

    International Nuclear Information System (INIS)

    Babenkov, M.I.; Zhdanov, V.S.

    2002-01-01

    simultaneous measurements of spectrum of final states of daughter helium ion on beta source backing. Spectral investigations of three electron Auger transition are also interesting; they allow receiving quality experimental information, which is necessary for adequate understanding of electron-electron correlation in atom. Intensity of these transitions is one orders less than intensity of ordinary two electrons Auger transitions. A high effectiveness of measurements, excellent relation of effect/background at effect tendency to zero and acceptable resolution make position-time spectrometer indispensable in special measurements of three-electrons Auger transitions, for example LL MMM

  10. Measurement of voice onset time in maxillectomy patients.

    Science.gov (United States)

    Hattori, Mariko; Sumita, Yuka I; Taniguchi, Hisashi

    2014-01-01

    Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients for objective speech evaluation. We examined voice onset time for /ka/ and /ta/ in 13 maxillectomy patients by calculating the number of valid measurements of voice onset time out of three trials for each syllable. Wilcoxon's signed rank test showed that voice onset time measurements were more successful for /ka/ and /ta/ when a prosthesis was used (Z = -2.232, P = 0.026 and Z = -2.401, P = 0.016, resp.) than when a prosthesis was not used. These results indicate a prosthesis affected voice onset measurement in these patients. Although more research in this area is needed, measurement of voice onset time has the potential to be used to evaluate consonant production in maxillectomy patients wearing a prosthesis.

  11. Measurement of Voice Onset Time in Maxillectomy Patients

    Directory of Open Access Journals (Sweden)

    Mariko Hattori

    2014-01-01

    Full Text Available Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients for objective speech evaluation. We examined voice onset time for /ka/ and /ta/ in 13 maxillectomy patients by calculating the number of valid measurements of voice onset time out of three trials for each syllable. Wilcoxon’s signed rank test showed that voice onset time measurements were more successful for /ka/ and /ta/ when a prosthesis was used (Z=−2.232, P=0.026 and Z=−2.401, P=0.016, resp. than when a prosthesis was not used. These results indicate a prosthesis affected voice onset measurement in these patients. Although more research in this area is needed, measurement of voice onset time has the potential to be used to evaluate consonant production in maxillectomy patients wearing a prosthesis.

  12. An Energy-Based Similarity Measure for Time Series

    Directory of Open Access Journals (Sweden)

    Pierre Brunagel

    2007-11-01

    Full Text Available A new similarity measure, called SimilB, for time series analysis, based on the cross-ΨB-energy operator (2004, is introduced. ΨB is a nonlinear measure which quantifies the interaction between two time series. Compared to Euclidean distance (ED or the Pearson correlation coefficient (CC, SimilB includes the temporal information and relative changes of the time series using the first and second derivatives of the time series. SimilB is well suited for both nonstationary and stationary time series and particularly those presenting discontinuities. Some new properties of ΨB are presented. Particularly, we show that ΨB as similarity measure is robust to both scale and time shift. SimilB is illustrated with synthetic time series and an artificial dataset and compared to the CC and the ED measures.

  13. Torque measurements reveal sequence-specific cooperative transitions in supercoiled DNA

    Science.gov (United States)

    Oberstrass, Florian C.; Fernandes, Louis E.; Bryant, Zev

    2012-01-01

    B-DNA becomes unstable under superhelical stress and is able to adopt a wide range of alternative conformations including strand-separated DNA and Z-DNA. Localized sequence-dependent structural transitions are important for the regulation of biological processes such as DNA replication and transcription. To directly probe the effect of sequence on structural transitions driven by torque, we have measured the torsional response of a panel of DNA sequences using single molecule assays that employ nanosphere rotational probes to achieve high torque resolution. The responses of Z-forming d(pGpC)n sequences match our predictions based on a theoretical treatment of cooperative transitions in helical polymers. “Bubble” templates containing 50–100 bp mismatch regions show cooperative structural transitions similar to B-DNA, although less torque is required to disrupt strand–strand interactions. Our mechanical measurements, including direct characterization of the torsional rigidity of strand-separated DNA, establish a framework for quantitative predictions of the complex torsional response of arbitrary sequences in their biological context. PMID:22474350

  14. Quality in transitional care of the elderly: Key challenges and relevant improvement measures

    Directory of Open Access Journals (Sweden)

    Marianne Storm

    2014-05-01

    Full Text Available Introduction: Elderly people aged over 75 years with multifaceted care needs are often in need of hospital treatment. Transfer across care levels for this patient group increases the risk of adverse events. The aim of this paper is to establish knowledge of quality in transitional care of the elderly in two Norwegian hospital regions by identifying issues affecting the quality of transitional care and based on these issues suggest improvement measures.Methodology: Included in the study were elderly patients (75+ receiving health care in the municipality admitted to hospital emergency department or discharged to community health care with hip fracture or with a general medical diagnosis. Participant observations of admission and discharge transitions (n = 41 were carried out by two researchers.Results: Six main challenges with belonging descriptions have been identified: (1 next of kin (bridging providers, advocacy, support, information brokering, (2 patient characteristics (level of satisfaction, level of insecurity, complex clinical conditions, (3 health care personnel's competence (professional, system, awareness of others’ roles, (4 information exchange (oral, written, electronic, (5 context (stability, variability, change incentives, number of patient handovers and (6 patient assessment (complex clinical picture, patient description, clinical assessment.Conclusion: Related to the six main challenges, several measures have been suggested to improve quality in transitional care, e.g. information to and involvement of patients and next of kin, staff training, standardisation of routines and inter-organisational staff meetings.

  15. Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System

    DEFF Research Database (Denmark)

    Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent

    2015-01-01

    BACKGROUND/AIMS: The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not ...

  16. Thermal lens and interferometric method for glass transition and thermo physical properties measurements in Nd2O3 doped sodium zincborate glass.

    Science.gov (United States)

    Astrath, N G C; Steimacher, A; Rohling, J H; Medina, A N; Bento, A C; Baesso, M L; Jacinto, C; Catunda, T; Lima, S M; Karthikeyan, B

    2008-12-22

    In this work the time resolved thermal lens method is combined with interferometric technique, the thermal relaxation calorimetry, photoluminescence and lifetime measurements to determine the thermo physical properties of Nd(2)O(3) doped sodium zincborate glass as a function of temperature up to the glass transition region. Thermal diffusivity, thermal conductivity, fluorescence quantum efficiency, linear thermal expansion coefficient and thermal coefficient of electronic polarizability were determined. In conclusion, the results showed the ability of thermal lens and interferometric methods to perform measurements very close to the phase transition region. These techniques provide absolute values for the measured physical quantities and are advantageous when low scan rates are required.

  17. How does landscape structure influence catchment transit time across different geomorphic provinces?

    Science.gov (United States)

    Tetzlaff, D.; Seibert, J.; McGuire, K.J.; Laudon, H.; Burns, Douglas A.; Dunn, S.M.; Soulsby, C.

    2009-01-01

    Despite an increasing number of empirical investigations of catchment transit times (TTs), virtually all are based on individual catchments and there are few attempts to synthesize understanding across different geographical regions. Uniquely, this paper examines data from 55 catchments in five geomorphic provinces in northern temperate regions (Scotland, United States of America and Sweden). The objective is to understand how the role of catchment topography as a control on the TTs differs in contrasting geographical settings. Catchment inverse transit time proxies (ITTPs) were inferred by a simple metric of isotopic tracer damping, using the ratio of standard deviation of ??18O in streamwater to the standard deviation of ??18O in precipitation. Quantitative landscape analysis was undertaken to characterize the catchments according to hydrologically relevant topographic indices that could be readily determined from a digital terrain model (DTM). The nature of topographic controls on transit times varied markedly in different geomorphic regions. In steeper montane regions, there are stronger gravitational influences on hydraulic gradients and TTs tend to be lower in the steepest catchments. In provinces where terrain is more subdued, direct topographic control weakened; in particular, where flatter areas with less permeable soils give rise to overland flow and lower TTs. The steeper slopes within this flatter terrain appear to have a greater coverage of freely draining soils, which increase sub-surface flow, therefore increasing TTs. Quantitative landscape analysis proved a useful tool for intercatchment comparison. However, the critical influence of sub-surface permeability and connectivity may limit the transferability of predictive tools of hydrological function based on topographic parameters alone. Copyright ?? 2009 John Wiley & Sons, Ltd.

  18. Runoff generating processes in adjacent tussock grassland and pine plantation catchments as indicated by mean transit time estimation using tritium

    Directory of Open Access Journals (Sweden)

    M. K. Stewart

    2010-06-01

    Full Text Available The east Otago uplands of New Zealand's South Island have long been studied because of the environmental consequences of converting native tussock grasslands to other land covers, notably forestry and pasture for stock grazing. Early studies showed that afforestation substantially reduced annual water yield, stream peak flows, and 7-day low flows, mainly as a consequence of increased interception. Tritium measurements have indicated that surprisingly old water is present in catchments GH1 and GH2, and the small headwater wetland and catchment (GH5, and contributes strongly to baseflow. The data have been simulated assuming the presence of two types of water in the baseflow, young water from shallow aquifers connecting hillside regolith with the stream, and old water from deep bedrock aquifers, respectively. The mean transit time of the young water is approximately one month, while that of the old water is 25–26 years as revealed by the presence of tritium originating from the bomb-peak in NZ rainfall in late 1960s and early 1970s. Such a long transit time indicates slow release from groundwater reservoirs within the bedrock, which constitute by far the larger of the water stores. Comparison of the results from catchments GH1 (tussock and GH2 (pine forest suggests that about equal quantities of water (85 mm/a are contributed from the deep aquifers in the two catchments, although runoff from the shallow aquifers has been strongly reduced by afforestation in GH2. This study has revealed the presence of a long transit time component of water in runoff in a catchment with crystalline metamorphic bedrock.

  19. Runoff generating processes in adjacent tussock grassland and pine plantation catchments as indicated by mean transit time estimation using tritium

    Science.gov (United States)

    Stewart, M. K.; Fahey, B. D.

    2010-06-01

    The east Otago uplands of New Zealand's South Island have long been studied because of the environmental consequences of converting native tussock grasslands to other land covers, notably forestry and pasture for stock grazing. Early studies showed that afforestation substantially reduced annual water yield, stream peak flows, and 7-day low flows, mainly as a consequence of increased interception. Tritium measurements have indicated that surprisingly old water is present in catchments GH1 and GH2, and the small headwater wetland and catchment (GH5), and contributes strongly to baseflow. The data have been simulated assuming the presence of two types of water in the baseflow, young water from shallow aquifers connecting hillside regolith with the stream, and old water from deep bedrock aquifers, respectively. The mean transit time of the young water is approximately one month, while that of the old water is 25-26 years as revealed by the presence of tritium originating from the bomb-peak in NZ rainfall in late 1960s and early 1970s. Such a long transit time indicates slow release from groundwater reservoirs within the bedrock, which constitute by far the larger of the water stores. Comparison of the results from catchments GH1 (tussock) and GH2 (pine forest) suggests that about equal quantities of water (85 mm/a) are contributed from the deep aquifers in the two catchments, although runoff from the shallow aquifers has been strongly reduced by afforestation in GH2. This study has revealed the presence of a long transit time component of water in runoff in a catchment with crystalline metamorphic bedrock.

  20. Characterisation of two-phase horizontal flow regime transition by the application of time-frequency analysis methods

    International Nuclear Information System (INIS)

    Seleghim, Paulo

    1996-01-01

    This work concerns the development of a methodology which objective is to characterize and diagnose two-phase flow regime transitions. The approach is based on the fundamental assumption that a transition flow is less stationary than a flow with an established regime. In a first time, the efforts focused on: 1) the design and construction of an experimental loop, allowing to reproduce the main horizontal two-phase flow patterns, in a stable and controlled way, 2) the design and construction of an electrical impedance probe, providing an imaged information of the spatial phase distribution in the pipe, the systematic study of the joint time-frequency and time-scale analysis methods, which permitted to define an adequate parameter quantifying the un-stationary degree. In a second time, in order to verify the fundamental assumption, a series of experiments were conducted, which objective was to demonstrate the correlation between un-stationary and regime transition. The un-stationary degree was quantified by calculating the Gabor's transform time-frequency covariance of the impedance probe signals. Furthermore, the phenomenology of each transition was characterized by the joint moments and entropy. The results clearly show that the regime transitions are correlated with local-time frequency covariance peaks, which demonstrates that these regime transitions are characterized by a loss of stationarity. Consequently, the time-frequency covariance constitutes an objective two-phase flow regime transition indicator. (author) [fr

  1. A deconvolution method for deriving the transit time spectrum for ultrasound propagation through cancellous bone replica models.

    Science.gov (United States)

    Langton, Christian M; Wille, Marie-Luise; Flegg, Mark B

    2014-04-01

    The acceptance of broadband ultrasound attenuation for the assessment of osteoporosis suffers from a limited understanding of ultrasound wave propagation through cancellous bone. It has recently been proposed that the ultrasound wave propagation can be described by a concept of parallel sonic rays. This concept approximates the detected transmission signal to be the superposition of all sonic rays that travel directly from transmitting to receiving transducer. The transit time of each ray is defined by the proportion of bone and marrow propagated. An ultrasound transit time spectrum describes the proportion of sonic rays having a particular transit time, effectively describing lateral inhomogeneity of transit times over the surface of the receiving ultrasound transducer. The aim of this study was to provide a proof of concept that a transit time spectrum may be derived from digital deconvolution of input and output ultrasound signals. We have applied the active-set method deconvolution algorithm to determine the ultrasound transit time spectra in the three orthogonal directions of four cancellous bone replica samples and have compared experimental data with the prediction from the computer simulation. The agreement between experimental and predicted ultrasound transit time spectrum analyses derived from Bland-Altman analysis ranged from 92% to 99%, thereby supporting the concept of parallel sonic rays for ultrasound propagation in cancellous bone. In addition to further validation of the parallel sonic ray concept, this technique offers the opportunity to consider quantitative characterisation of the material and structural properties of cancellous bone, not previously available utilising ultrasound.

  2. Kinetics and mechanism of transitions involving the lamellar, cubic, inverted hexagonal, and fluid isotropic phases of hydrated monoacylglycerides monitored by time-resolved X-ray diffraction

    International Nuclear Information System (INIS)

    Caffrey, M.

    1987-01-01

    A study of the dynamics and mechanism of the various thermotropic phase transitions undergone by the hydrated monoacylglycerides monoolein and monoelaidin, in the temperature range of 20-120 0 C and from 0 to 5 M NaCl, has been undertaken. Measurements were made by using time-resolved X-ray diffraction at the Cornell High-Energy Synchrotron Source. The lamellar chain order/disorder, lamellar/cubic (body centered, space group No.8), cubic (body centered, No.8)/cubic (primitive No.4), cubic (body centered, No.12)/cubic (primitive, No.4), cubic (primitive, No.4)/fluid isotropic, cubic (body centered, No.12)/inverted hexagonal, cubic (primitive, No.4)/inverted hexagonal, and hexagonal/fluid isotropic transitions were examined under active heating and passive cooling by using a jump in temperature to effect phase transformation. All of the transitions with the exception of the cubic (body centered, No.8)/cubic (primitive, No.4) and the cubic (body centered, No.12)/cubic (primitive, No.4) cooling transitions were found (1) to be repeatable, (2) to be reversible, and (3) to have an upper bound on the transit time (time required to complete the transition) of ≤ 3s. In addition to the time-resolved measurements, data were obtained on the stability of the various phases in the temperature range of 20-120 0 C and from 0 to 5 M NaCl. In the case of fully hydrated monoolein, high salt strongly favors the hexagonal over the cubic (body centered, No.8) phase and slightly elevates the hexagonal/fluid isotropic transition temperature. With fully hydrated monoelaidin, the hexagonal phase which is not observed in the absence of salt becomes the dominant phase at high salt concentration

  3. GARUSO - Version 1.0. Uncertainty model for multipath ultrasonic transit time gas flow meters

    Energy Technology Data Exchange (ETDEWEB)

    Lunde, Per; Froeysa, Kjell-Eivind; Vestrheim, Magne

    1997-09-01

    This report describes an uncertainty model for ultrasonic transit time gas flow meters configured with parallel chords, and a PC program, GARUSO Version 1.0, implemented for calculation of the meter`s relative expanded uncertainty. The program, which is based on the theoretical uncertainty model, is used to carry out a simplified and limited uncertainty analysis for a 12`` 4-path meter, where examples of input and output uncertainties are given. The model predicts a relative expanded uncertainty for the meter at a level which further justifies today`s increasing tendency to use this type of instruments for fiscal metering of natural gas. 52 refs., 15 figs., 11 tabs.

  4. Predicting critical transitions in dynamical systems from time series using nonstationary probability density modeling.

    Science.gov (United States)

    Kwasniok, Frank

    2013-11-01

    A time series analysis method for predicting the probability density of a dynamical system is proposed. A nonstationary parametric model of the probability density is estimated from data within a maximum likelihood framework and then extrapolated to forecast the future probability density and explore the system for critical transitions or tipping points. A full systematic account of parameter uncertainty is taken. The technique is generic, independent of the underlying dynamics of the system. The method is verified on simulated data and then applied to prediction of Arctic sea-ice extent.

  5. On some practical consideration of the electron beam breakup transit time oscillator

    International Nuclear Information System (INIS)

    Kwan, T.J.T.

    1992-01-01

    The electron beam breakup transit time oscillator (BTO) makes use of the interaction between an electron beam and the azimuthally azimuthally asymmetric transverse magnetic mode (TM 110 ) of a cavity to facilitate the exchange of energy between them. Linear theory has shown a large growth rate in the regime where space-charge effects can be ignored. In this study, we have investigated the non-ideal elements in the BTO and evaluated their effects accordingly. The practical issues under consideration are electron beam quality, energy, and space-charge potential. Our calculations indicate only a modest unfavorable scalings with respect to these parameters

  6. Time-dependent local-to-normal mode transition in triatomic molecules

    Science.gov (United States)

    Cruz, Hans; Bermúdez-Montaña, Marisol; Lemus, Renato

    2018-01-01

    Time-evolution of the vibrational states of two interacting harmonic oscillators in the local mode scheme is presented. A local-to-normal mode transition (LNT) is identified and studied from temporal perspective through time-dependent frequencies of the oscillators. The LNT is established as a polyad-breaking phenomenon from the local standpoint for the stretching degrees of freedom in a triatomic molecule. This study is carried out in the algebraic representation of bosonic operators. The dynamics of the states are determined via the solutions of the corresponding nonlinear Ermakov equation and a local time-dependent polyad is obtained as a tool to identify the LNT. Applications of this formalism to H2O, CO2, O3 and NO2 molecules in the adiabatic, sudden and linear regime are considered.

  7. Direct simulation of groundwater transit-time distributions using the reservoir theory

    Science.gov (United States)

    Etcheverry, David; Perrochet, Pierre

    Groundwater transit times are of interest for the management of water resources, assessment of pollution from non-point sources, and quantitative dating of groundwaters by the use of environmental isotopes. The age of water is the time water has spent in an aquifer since it has entered the system, whereas the transit time is the age of water as it exits the system. Water at the outlet of an aquifer is a mixture of water elements with different transit times, as a consequence of the different flow-line lengths. In this paper, transit-time distributions are calculated by coupling two existing methods, the reservoir theory and a recent age-simulation method. Based on the derivation of the cumulative age distribution over the whole domain, the approach accounts for the whole hydrogeological framework. The method is tested using an analytical example and its applicability illustrated for a regional layered aquifer. Results show the asymmetry and multimodality of the transit-time distribution even in advection-only conditions, due to the aquifer geometry and to the velocity-field heterogeneity. Résumé Les temps de transit des eaux souterraines sont intéressants à connaître pour gérer l'évaluation des ressources en eau dans le cas de pollution à partir de sources non ponctuelles, et aussi pour dater quantitativement les eaux souterraines au moyen des isotopes du milieu. L'âge de l'eau est le temps qu'elle a passé dans un aquifère depuis qu'elle est entrée dans le système, alors que le temps de transit est l'âge de l'eau au moment où elle quitte le système. L'eau à la sortie d'un aquifère est un mélange d'eaux possédant différents temps de transit, du fait des longueurs différentes des lignes de courant suivies. Dans ce papier, les distributions des temps de transit sont calculées en couplant deux méthodes, la théorie du réservoir et une méthode récente de simulation des âges. Basée sur la dérivation de la distribution cumulées des âges sur

  8. Fourier Collocation Approach With Mesh Refinement Method for Simulating Transit-Time Ultrasonic Flowmeters Under Multiphase Flow Conditions.

    Science.gov (United States)

    Simurda, Matej; Duggen, Lars; Basse, Nils T; Lassen, Benny

    2018-02-01

    A numerical model for transit-time ultrasonic flowmeters operating under multiphase flow conditions previously presented by us is extended by mesh refinement and grid point redistribution. The method solves modified first-order stress-velocity equations of elastodynamics with additional terms to account for the effect of the background flow. Spatial derivatives are calculated by a Fourier collocation scheme allowing the use of the fast Fourier transform, while the time integration is realized by the explicit third-order Runge-Kutta finite-difference scheme. The method is compared against analytical solutions and experimental measurements to verify the benefit of using mapped grids. Additionally, a study of clamp-on and in-line ultrasonic flowmeters operating under multiphase flow conditions is carried out.

  9. Measurement-theoretic foundations of time discounting in economics

    OpenAIRE

    Conrad Heilmann

    2008-01-01

    In economics, the concept of time discounting introduces weights on future goods to make these less valuable. Yet, both the conceptual motivation for time discounting and its specic functional form remain contested. To address these problems, this paper provides a measurement-theoretic framework of representation for time discounting. The representation theorem characterises time discounting factors by representations of time dierences. This general result can be interpreted with existing the...

  10. Social climber attachment in forming networks produces a phase transition in a measure of connectivity

    Science.gov (United States)

    Taylor, Dane; Larremore, Daniel B.

    2012-09-01

    The formation and fragmentation of networks are typically studied using percolation theory, but most previous research has been restricted to studying a phase transition in cluster size, examining the emergence of a giant component. This approach does not study the effects of evolving network structure on dynamics that occur at the nodes, such as the synchronization of oscillators and the spread of information, epidemics, and neuronal excitations. We introduce and analyze an alternative link-formation rule, called social climber (SC) attachment, that may be combined with arbitrary percolation models to produce a phase transition using the largest eigenvalue of the network adjacency matrix as the order parameter. This eigenvalue is significant in the analyses of many network-coupled dynamical systems in which it measures the quality of global coupling and is hence a natural measure of connectivity. We highlight the important self-organized properties of SC attachment and discuss implications for controlling dynamics on networks.

  11. Landuse effects on runoff generating processes in tussock grassland indicated by mean transit time estimation using tritium

    Science.gov (United States)

    Stewart, M. K.; Fahey, B. D.

    2010-02-01

    The east Otago uplands of New Zealand's South Island have long been studied because of the environmental consequences of converting native tussock grasslands to other land covers, notably forestry and pasture for stock grazing. Early studies showed that afforestation substantially reduced annual water yield, stream peak flows, and 7-day low flows, mainly as a consequence of increased interception. Tritium measurements have indicated that surprisingly old water is present in catchments GH1 and GH2, and the small headwater wetland and catchment (GH5). The old water contributes strongly to baseflow (and therefore also to quickflow). The data have been simulated assuming the presence of two types of water in the baseflow, young water from shallow aquifers connecting hillside regolith with the stream, and old water from deep bedrock aquifers, respectively. The mean transit time of the young water is of the order of months, while that of the old water is 25-26 years as revealed by the presence of tritium originating from the bomb-peak in NZ rainfall in late 1960s and early 1970s. Such a long transit time indicates slow release from groundwater reservoirs within the bedrock, which constitute by far the larger of the water stores. Comparison of the results from catchments GH1 (tussock) and GH2 (pine forest) suggests that about equal quantities of water (85 mm annually) are contributed from the deep aquifers in the two catchments, although runoff from the shallow aquifers has been strongly reduced by afforestation in GH2.

  12. In situ observation of sol-gel transition of agarose aqueous solution by fluorescence measurement.

    Science.gov (United States)

    Wang, Zheng; Yang, Kun; Li, Haining; Yuan, Chaosheng; Zhu, Xiang; Huang, Haijun; Wang, Yongqiang; Su, Lei; Fang, Yapeng

    2018-06-01

    Sol-gel transition behavior of agarose aqueous solution was investigated by using rheology and fluorescence measurement. On heating, the storage modulus G' decreased gradually, then deviated abruptly at the temperature of about 65°C, and finally decreased slowly again. For fluorescence measurement, the phase transition point kept almost at the temperature of 65°C, which was consistent with that in rheology measurement. Upon compression, it was indicated that the fluorescence lifetime for the probe in the agarose aqueous solution showed a dramatic change in the vicinity of the phase transition point. T vs. P phase diagram of agarose aqueous solution was constructed, which showed that the melting point was an increasing function of pressure. Based on the phase diagram, the agarose gels were prepared by cooling under atmospheric pressure and the pressure of 300MPa, respectively. From the result of the recovered samples studied by optical rheometry, it was found that agarose gel prepared under high pressure had a higher elasticity and lower viscosity index, compared with that under atmospheric pressure. It could be speculated that such kinds of properties might be attributed to the smaller pore size during gelation under high pressure. Copyright © 2018. Published by Elsevier B.V.

  13. Effect of closed loop cooling water transit time on containment cooling

    International Nuclear Information System (INIS)

    Smith, R.P.; Vossahlik, J.E.; Goodwin, E.F.

    1996-01-01

    Long term containment cooling analyses in nuclear plant systems are usually conducted assuming a quasi steady-state process, that is, a steady state evaluation of the cooling system is completed for each calculational step. In reality, fluid transport in the system, and heat addition to system components may affect the heat removal rate of the system. Transient effects occurring during system startup may affect the maximum temperatures experienced in the system. It is important to ensure that such transient effects do not affect operation of the system (e.g., cause a high temperature trip). To evaluate the effect of fluid transit delays, a closed loop cooling water system model has been developed that incorporates the fluid transport times when determining the closed loop cooling system performance. This paper describes the closed loop cooling system model as implemented in the CONTEMPT-LT/028 code. The evaluation of the transient temperature response of the closed loop cooling system using the model is described. The paper also describes the effect of fluid transit time on the overall containment cooling performance

  14. Phase transition of the susceptible-infected-susceptible dynamics on time-varying configuration model networks

    Science.gov (United States)

    St-Onge, Guillaume; Young, Jean-Gabriel; Laurence, Edward; Murphy, Charles; Dubé, Louis J.

    2018-02-01

    We present a degree-based theoretical framework to study the susceptible-infected-susceptible (SIS) dynamics on time-varying (rewired) configuration model networks. Using this framework on a given degree distribution, we provide a detailed analysis of the stationary state using the rewiring rate to explore the whole range of the time variation of the structure relative to that of the SIS process. This analysis is suitable for the characterization of the phase transition and leads to three main contributions: (1) We obtain a self-consistent expression for the absorbing-state threshold, able to capture both collective and hub activation. (2) We recover the predictions of a number of existing approaches as limiting cases of our analysis, providing thereby a unifying point of view for the SIS dynamics on random networks. (3) We obtain bounds for the critical exponents of a number of quantities in the stationary state. This allows us to reinterpret the concept of hub-dominated phase transition. Within our framework, it appears as a heterogeneous critical phenomenon: observables for different degree classes have a different scaling with the infection rate. This phenomenon is followed by the successive activation of the degree classes beyond the epidemic threshold.

  15. DA-9701 improves colonic transit time and symptoms in patients with functional constipation: A prospective study.

    Science.gov (United States)

    Kim, Su Young; Woo, Hyun Sun; Kim, Kyoung Oh; Choi, Sung Han; Kwon, Kwang An; Chung, Jun-Won; Kim, Yoon Jae; Kim, Jung Ho; Kim, Su Ji; Park, Dong Kyun

    2017-12-01

    DA-9701, a newly developed prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, has been shown to effectively treat functional dyspepsia. Recently, it has also been suspected to improve gastrointestinal motor function. The aims of this study were to assess the effect of DA-9701 on colonic transit time (CTT) and symptoms of functional constipation. Thirty-three patients with functional constipation based on the Rome III criteria were prospectively enrolled. The patients received 30-mg DA-9701 three times a day for 24 days. CTT was estimated initially and at the end of treatment. Symptoms such as spontaneous bowel movements, straining, stool form, feeling of incomplete emptying and anorectal blockage, abdominal discomfort and pain, overall defecation satisfaction, and incidence of adverse events were also analyzed. Twenty-seven patients completed the study. DA-9701 was associated with a significantly reduced CTT from 34.9 ± 17.6 to 23.7 ± 19.1 h (P = 0.001). Segmental CTT also significantly decreased after treatment (right CTT: from 16.8 [0.0-28.8] to 6.0 [0.0-25.2] hours, P DA-9701 accelerates colonic transit and safely improves symptoms in patients with functional constipation. Therefore, we suggest that this novel agent could help to treat patients with this condition. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  16. Suppression of the Transit -Time Instability in Large-Area Electron Beam Diodes

    Science.gov (United States)

    Myers, Matthew C.; Friedman, Moshe; Swanekamp, Stephen B.; Chan, Lop-Yung; Ludeking, Larry; Sethian, John D.

    2002-12-01

    Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm × 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%.

  17. Suppression of the transit-time instability in large-area electron beam diodes

    International Nuclear Information System (INIS)

    Myers, Matthew C.; Friedman, Moshe; Sethian, John D.; Swanekamp, Stephen B.; Chan, L.-Y.; Ludeking, Larry

    2002-01-01

    Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm x 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%

  18. Measurements of Rationality: Individual Differences in Information Processing, the Transitivity of Preferences and Decision Strategies.

    Science.gov (United States)

    Sleboda, Patrycja; Sokolowska, Joanna

    2017-01-01

    The first goal of this study was to validate the Rational-Experiential Inventory ( REI ) and the Cognitive Reflection Test ( CRT ) through checking their relation to the transitivity axiom. The second goal was to test the relation between decision strategies and cognitive style as well as the relation between decision strategies and the transitivity of preferences. The following characteristics of strategies were investigated: requirements for trade-offs, maximization vs. satisficing and option-wise vs. attribute-wise information processing. Respondents were given choices between two multi-attribute options. The options were designed so that the choice indicated which strategy was applied. Both the REI-R and the CRT were found to be good predictors of the transitivity of preferences. Respondents who applied compensatory strategies and the maximization criterion scored highly on the REI-R and in the CRT , whereas those who applied the satisficing rule scored highly on the REI-R but not in the CRT . Attribute-wise information processing was related to low scores in both measurements. Option-wise information processing led to a high transitivity of preferences.

  19. Mode transition in bubbly Taylor-Couette flow measured by PTV

    International Nuclear Information System (INIS)

    Yoshida, K; Tasaka, Y; Murai, Y; Takeda, T

    2009-01-01

    The drag acting to the inner cylinder in Taylor-Couette flow system can be reduced by bubble injection. In this research, relationship between drag reduction and change of vortical structure in a Taylor-Couette flow is investigated by Particle Tracking Velocimetry (PTV). The velocity vector field in the r-z cross section and the bubble concentration in the front view (z-θ plane) are measured. This paper describes the change of vortical structures with bubbles, and the mode transition that is sensitively affected by the bubbles is discussed. The bubbles accumulate in the three parts relative to vortex position by the interaction between bubbles and vortices. The status of bubble's distribution is different depending on position. This difference affects mode transition as its trigger significantly. The presence of bubbles affects the transition from toroidal mode to spiral mode but does not induce the transition from spiral mode to toroidal mode. Further we found that Taylor vortex bifurcates and a pair of vortices coalesces when the flow switches between spiral mode and toroidal mode.

  20. Transitions among Health States Using 12 Measures of Successful Aging in Men and Women: Results from the Cardiovascular Health Study

    Directory of Open Access Journals (Sweden)

    Stephen Thielke

    2012-01-01

    Full Text Available Introduction. Successful aging has many dimensions, which may manifest differently in men and women at different ages. Methods. We characterized one-year transitions among health states in 12 measures of successful aging among adults in the Cardiovascular Health Study. The measures included self-rated health, ADLs, IADLs, depression, cognition, timed walk, number of days spent in bed, number of blocks walked, extremity strength, recent hospitalizations, feelings about life as a whole, and life satisfaction. We dichotomized variables into “healthy” or “sick,” states, and estimated the prevalence of the healthy state and the probability of transitioning from one state to another, or dying, during yearly intervals. We compared men and women and three age groups (65–74, 75–84, and 85–94. Findings. Measures of successful aging showed similar results by gender. Most participants remained healthy even into advanced ages, although health declined for all measures. Recuperation, although less common with age, still occurred frequently. Men had a higher death rate than women regardless of health status, and were also more likely to remain in the healthy state. Discussion. The results suggest a qualitatively different experience of successful aging between men and women. Men did not simply “age faster” than women.