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Sample records for transit-time flow meter

  1. 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 fluctuations...

  2. Modelling of transit-time ultrasonic flow meters under multi-phase flow conditions

    DEFF Research Database (Denmark)

    Simurda, Matej; Duggen, Lars; Lassen, Benny

    2016-01-01

    of the background flow are included. Spatial derivatives are calculated by a Fourier collocation scheme allowing the use of the Fast Fourier transform. The method is compared against analytical solutions and experimental measurements. Additionally, a study of clamp-on and in-line ultrasonic flowmeters operating......A pseudospectral model for transit time ultrasonic flowmeters under multiphase flow conditions is presented. The method solves first order stress-velocity equations of elastodynamics, with acoustic media being modelled by setting shear modulus to zero. Additional terms to account for the effect...... under multiphase flow conditions is carried out....

  3. Peak flow meter (image)

    Science.gov (United States)

    A peak flow meter is commonly used by a person with asthma to measure the amount of air that can be ... become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow ...

  4. Peak flow meter use - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100202.htm Peak flow meter use - Series—Peak flow meter use - part one To use the sharing ... slide 7 out of 7 Overview A peak flow meter helps you check how well your asthma ...

  5. 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....../min. Transit time flow was measured continuously. The results showed very accurate flow measurements at all flow rates when compared to the known infusion rate of the Gemini pump. However, at flow rates below 4 ml/min, variation became a problem....

  6. Liquid ultrasonic flow meters for crude oil measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kalivoda, Raymond J.; Lunde, Per

    2005-07-01

    Liquid ultrasonic flow meters (LUFMs) are gaining popularity for the accurate measurement of petroleum products. In North America the first edition of the API standard ''Measurement of liquid hydrocarbons by ultrasonic flow meters using transit time technology'' was issued in February 2005. It addresses both refined petroleum products and crude oil applications. Its field of application is mainly custody transfer applications but it does provide general guidelines for the installation and operation of LUFM's other applications such as allocation, check meters and leak detection. As with all new technologies performance claims are at times exaggerated or misunderstood and application knowledge is limited. Since ultrasonic meters have no moving parts they appear to have fewer limitations than other liquid flow meters. Liquids ultrasonic flow meters, like turbine meters, are sensitive to fluid properties. It is increasingly more difficult to apply on high viscosity products then on lighter hydrocarbon products. Therefore application data or experience on the measurement of refined or light crude oil may not necessarily be transferred to measuring medium to heavy crude oils. Before better and more quantitative knowledge is available on how LUFMs react on different fluids, the arguments advocating reduced need for in-situ proving and increased dependency on laboratory flow calibration (e.g. using water instead of hydrocarbons) may be questionable. The present paper explores the accurate measurement of crude oil with liquid ultrasonic meters. It defines the unique characteristics of the different API grades of crude oils and how they can affect the accuracy of the liquid ultrasonic measurement. Flow testing results using a new LUFM design are discussed. The paper is intended to provide increased insight into the potentials and limitations of crude oil measurement using ultrasonic flow meters. (author) (tk)

  7. FLOW METERS WITH VERY GOOD PERFORMANCES

    Directory of Open Access Journals (Sweden)

    Mircea Dimitrie CAZACU

    2011-11-01

    Full Text Available We present the theoretical calculus of a patented flow meter, concerning such the thermodynamic and aerodynamic calculus, as well as the offered precision to measure the flow of the air in any meteorological conditions. In the same time we remark that the proposed flow meter, by its positioning, has not loss of head.

  8. A flow meter for ultrasonically measuring the flow velocity of fluids

    DEFF Research Database (Denmark)

    2015-01-01

    The invention regards a flow meter for ultrasonically measuring the flow velocity of fluids comprising a duct having a flow channel with an internal cross section comprising variation configured to generate at least one acoustic resonance within the flow channel for a specific ultrasonic frequency......, and at least two transducers for generating and sensing ultrasonic pulses, configured to transmit ultrasonic pulses at least at said specific ultrasonic frequency into the flow channel such that the ultrasonic pulses propagate through a fluid flowing in the flow channel, wherein the flow meter is configured...... to determine the flow velocity of the fluid flowing in the flow channel based on a change in transit time, phase and/or pulse such as amplitude and/or form, of the ultrasonic pulses....

  9. Turbine flow meter response in two-phase flows

    International Nuclear Information System (INIS)

    Shim, W.J.; Dougherty, T.J.; Cheh, H.Y.

    1996-01-01

    The purpose of this paper is to suggest a simple method of calibrating turbine flow meters to measure the flow rates of each phase in a two-phase flow. The response of two 50.8 mm (2 inch) turbine flow meters to air-water, two-phase mixtures flowing vertically in a 57 mm I.D. (2.25 inch) polycarbonate tube has been investigated for both upflow and downflow. The flow meters were connected in series with an intervening valve to provide an adjustable pressure difference between them. Void fractions were measured by two gamma densitometers, one upstream of the flow meters and the other downstream. The output signal of the turbine flow meters was found to depend only on the actual volumetric flow rate of the gas, F G , and liquid, F L , at the location of the flow meter

  10. Liquid metal Flow Meter - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, C.; Hoogendoom, S.; Hudson, B.; Prince, J.; Teichert, K.; Wood, J.; Chase, K.

    2007-01-30

    Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.

  11. Soft-sensing, non-intrusive multiphase flow meter

    NARCIS (Netherlands)

    Wrobel, K.; Schiferli, W.

    2009-01-01

    For single phase flow meters more and better non-intrusive or even clamp-on meters become available. This allows for a wider use of meters and for easier flow control. As the demand for multiphase meters is increasing, the current aim is to develop a non-intrusive multiphase flow meter. The

  12. Comparison of five portable peak flow meters

    Directory of Open Access Journals (Sweden)

    Glaucia Nency Takara

    2010-01-01

    Full Text Available OBJECTIVE: To compare the measurements of spirometric peak expiratory flow (PEF from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. METHODS: Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05, Spearman's correlation test and Bland-Altman's agreement test. RESULTS: The median and interquartile ranges for the spirometric values and the Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® meters were 428 (263-688 L/min, 450 (350-800 L/min, 420 (310-720 L/min, 380 (300-735 L/min, 400 (310-685 L/min and 415 (335-610 L/min, respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone® (p<0.001 and Galemed ® (p<0.01 meters. There was no agreement between the spirometric values and the five PEF meters. CONCLUSIONS: The results suggest that the values recorded from Galemed® meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone® meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  13. Comparison of five portable peak flow meters.

    Science.gov (United States)

    Takara, Glaucia Nency; Ruas, Gualberto; Pessoa, Bruna Varanda; Jamami, Luciana Kawakami; Di Lorenzo, Valéria Amorim Pires; Jamami, Mauricio

    2010-05-01

    To compare the measurements of spirometric peak expiratory flow (PEF) from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone, Assess, Galemed, Personal Best and Vitalograph peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman's test with Dunn's post-hoc (p<0.05), Spearman's correlation test and Bland-Altman's agreement test. The median and interquartile ranges for the spirometric values and the Air Zone, Assess, Galemed, Personal Best and Vitalograph meters were 428 (263-688 L/min), 450 (350-800 L/min), 420 (310-720 L/min), 380 (300-735 L/min), 400 (310-685 L/min) and 415 (335-610 L/min), respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone(R) (p<0.001) and Galemed (p<0.01) meters. There was no agreement between the spirometric values and the five PEF meters. The results suggest that the values recorded from Galemed meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices' results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters.

  14. Reciprocity and its utilization in ultrasonic flow meters

    Energy Technology Data Exchange (ETDEWEB)

    Lunde, Per; Vestrheim, Magne; Boe, Reidar; Smoergrav, Skule; Abrahamsen, Atle K.

    2005-07-01

    In ultrasonic transit time flow meters for gas and liquid (USMs), the flow direction, the flow velocity and the sound velocity are estimated from the measured up- and downstream transit times. At no-flow conditions, the up- and downstream transit times of such meters should ideally be the same, or the difference should be negligible. This may not be the case unless special precautions are made. In order to reduce the possibility of the meter to detect a false flow at no-flow conditions, USMs are typically ''dry calibrated'' before being installed in the field. ''Dry calibration'' (which may be made in different ways), in general involves measurement of (a) the time delays due to electronics, cables and transducers, (b) the so called ''{delta}t-correction'' (for each acoustic path, also denoted ''zero flow offset factor''), and (c) geometrical parameters. Various {delta}t-correction approaches may be used by different manufacturers, but these are basically similar and have the same purpose: to reduce the false flow detection and improve the accuracy at low and no-flow conditions (''zero flow adjustment''), without significantly affecting the accuracy at the high velocity measurements. The AGA-9 report and the API MPMS Ch. 5.8 standard both prescribe need for ''zero flow verification test (zero test)'' or ''zeroing the meter'', for gas and liquid USMs, respectively. Advances in USM technology based on the electro acoustic reciprocity principle have provided methods for reduction or even neglect ion of the need for ''{delta} t-correction'' of USMs. That means, if the USM measurement system is reciprocal, and operated in a ''sufficiently reciprocal'' way, the ''{delta}t-correction'' may be negligibly small over the operational range of pressure and temperature, and

  15. Multiphase flow metering: 4 years on

    Energy Technology Data Exchange (ETDEWEB)

    Falcone, G.; Hewitt, G.F.; Alimonti, C.; Harrison, B.

    2005-07-01

    Since the authors' last review in 2001 [1], the use of Multiphase Flow Metering (MFM) within the oil and gas industry continues to grow apace, being more popular in some parts of the world than others. Since the early 1990's, when the first commercial meters started to appear, there have been more than 1,600 field applications of MFM for field allocation, production optimisation and mobile well testing. As the authors predicted, wet gas metering technology has improved to such an extent that its use has rapidly increased worldwide. A ''who's who'' of the MFM sector is provided, which highlights the mergers in the sector and gives an insight into the meters and measurement principles available today. Cost estimates, potential benefits and reliability in the field of the current MFM technologies are revisited and brought up to date. Several measurements technologies have resurfaced, such as passive acoustic energy patterns, infrared wavelengths, Nuclear Magnetic Resonance (NMR) and Electrical Capacitance Tomography (ECT), and they are becoming commercial. The concept of ''virtual metering'', integrated with ''classical MFM'', is now widely accepted. However, sometimes the principles of the MFM measurements themselves are forgotten, submerged in the sales and marketing hype. (author) (tk)

  16. Capillary transit time heterogeneity and flow-metabolism coupling after traumatic brain injury

    Science.gov (United States)

    Østergaard, Leif; Engedal, Thorbjørn S; Aamand, Rasmus; Mikkelsen, Ronni; Iversen, Nina K; Anzabi, Maryam; Næss-Schmidt, Erhard T; Drasbek, Kim R; Bay, Vibeke; Blicher, Jakob U; Tietze, Anna; Mikkelsen, Irene K; Hansen, Brian; Jespersen, Sune N; Juul, Niels; Sørensen, Jens CH; Rasmussen, Mads

    2014-01-01

    Most patients who die after traumatic brain injury (TBI) show evidence of ischemic brain damage. Nevertheless, it has proven difficult to demonstrate cerebral ischemia in TBI patients. After TBI, both global and localized changes in cerebral blood flow (CBF) are observed, depending on the extent of diffuse brain swelling and the size and location of contusions and hematoma. These changes vary considerably over time, with most TBI patients showing reduced CBF during the first 12 hours after injury, then hyperperfusion, and in some patients vasospasms before CBF eventually normalizes. This apparent neurovascular uncoupling has been ascribed to mitochondrial dysfunction, hindered oxygen diffusion into tissue, or microthrombosis. Capillary compression by astrocytic endfeet swelling is observed in biopsies acquired from TBI patients. In animal models, elevated intracranial pressure compresses capillaries, causing redistribution of capillary flows into patterns argued to cause functional shunting of oxygenated blood through the capillary bed. We used a biophysical model of oxygen transport in tissue to examine how capillary flow disturbances may contribute to the profound changes in CBF after TBI. The analysis suggests that elevated capillary transit time heterogeneity can cause critical reductions in oxygen availability in the absence of ‘classic' ischemia. We discuss diagnostic and therapeutic consequences of these predictions. PMID:25052556

  17. 40 CFR 1065.220 - Fuel flow meter.

    Science.gov (United States)

    2010-07-01

    ... flow meter that meets the specifications in Table 1 of § 1065.205. We recommend a fuel flow meter that... diameters) or by using specially designed tubing bends, straightening fins, or pneumatic pulsation dampeners...

  18. Radiotracer techniques for measuring fluid flow and calibrating flow meters

    International Nuclear Information System (INIS)

    Cooper, E.L.

    1987-08-01

    Radiotracer techniques can be used to measure accurately both gas and liquid flow rates under operating conditions in a wide range of flow systems. They are ideally suited for calibrating flow meters as well as for measuring unmetered flows in industrial plants. Applications of these techniques range from measuring the flows of fuels and process fluids for energy and mass balance studies to measuring the flows of liquid and airborne effluents for pollution control. This report describes the various radiotracer techniques which can be used to measure fluid flows. The range of application and inherent accuracy of each technique is discussed

  19. Two-Phase Quality/Flow Meter

    Science.gov (United States)

    Moerk, J. Steven (Inventor); Youngquist, Robert C. (Inventor); Werlink, Rudy J. (Inventor)

    1999-01-01

    A quality and/or flow meter employs a capacitance probe assembly for measuring the dielectric constant of flow stream, particularly a two-phase flow stream including liquid and gas components.ne dielectric constant of the flow stream varies depending upon the volume ratios of its liquid and gas components, and capacitance measurements can therefore be employed to calculate the quality of the flow, which is defined as the volume ratio of liquid in the flow to the total volume ratio of gas and liquid in the flow. By using two spaced capacitance sensors, and cross-correlating the time varying capacitance values of each, the velocity of the flow stream can also be determined. A microcontroller-based processing circuit is employed to measure the capacitance of the probe sensors.The circuit employs high speed timer and counter circuits to provide a high resolution measurement of the time interval required to charge each capacitor in the probe assembly. In this manner, a high resolution, noise resistant, digital representation of each of capacitance value is obtained without the need for a high resolution A/D converter, or a high frequency oscillator circuit. One embodiment of the probe assembly employs a capacitor with two ground plates which provide symmetry to insure that accurate measurements are made thereby.

  20. FUSION OF VENTURI AND ULTRASONIC FLOW METER FOR ENHANCED FLOW METER CHARACTERISTICS USING FUZZY LOGIC

    Directory of Open Access Journals (Sweden)

    K.V. Santhosh

    2015-04-01

    Full Text Available This paper proposes a technique for measurement of liquid flow using venturi and ultrasonic flow meter(UFM to have following objectives a to design a multi-sensor data fusion (MSDF architecture for using both the sensors, b improve sensitivity and linearity of venturi and ultrasonic flow meter, and c detect and diagnosis of faults in sensor if any. Fuzzy logic algorithm is used to fuse outputs of both the sensor and train the fuzzy block to produces output which has an improved characteristics in terms of both sensitivity and linearity. For identification of sensor faults a comparative test algorithm is designed. Once trained proposed technique is tested in real life, results show successful implementation of proposed objectives.

  1. Gas flow meter and method for measuring gas flow rate

    Science.gov (United States)

    Robertson, Eric P.

    2006-08-01

    A gas flow rate meter includes an upstream line and two chambers having substantially equal, fixed volumes. An adjustable valve may direct the gas flow through the upstream line to either of the two chambers. A pressure monitoring device may be configured to prompt valve adjustments, directing the gas flow to an alternate chamber each time a pre-set pressure in the upstream line is reached. A method of measuring the gas flow rate measures the time required for the pressure in the upstream line to reach the pre-set pressure. The volume of the chamber and upstream line are known and fixed, thus the time required for the increase in pressure may be used to determine the flow rate of the gas. Another method of measuring the gas flow rate uses two pressure measurements of a fixed volume, taken at different times, to determine the flow rate of the gas.

  2. Modelling mean transit time of stream base flow during tropical cyclone rainstorm in a steep relief forested catchment

    Science.gov (United States)

    Lee, Jun-Yi; Huang, -Chuan, Jr.

    2017-04-01

    Mean transit time (MTT) is one of the of fundamental catchment descriptors to advance understanding on hydrological, ecological, and biogeochemical processes and improve water resources management. However, there were few documented the base flow partitioning (BFP) and mean transit time within a mountainous catchment in typhoon alley. We used a unique data set of 18O isotope and conductivity composition of rainfall (136 mm to 778 mm) and streamflow water samples collected for 14 tropical cyclone events (during 2011 to 2015) in a steep relief forested catchment (Pinglin, in northern Taiwan). A lumped hydrological model, HBV, considering dispersion model transit time distribution was used to estimate total flow, base flow, and MTT of stream base flow. Linear regression between MTT and hydrometric (precipitation intensity and antecedent precipitation index) variables were used to explore controls on MTT variation. Results revealed that both the simulation performance of total flow and base flow were satisfactory, and the Nash-Sutcliffe model efficiency coefficient of total flow and base flow was 0.848 and 0.732, respectively. The event magnitude increased with the decrease of estimated MTTs. Meanwhile, the estimated MTTs varied 4-21 days with the increase of BFP between 63-92%. The negative correlation between event magnitude and MTT and BFP showed the forcing controls the MTT and BFP. Besides, a negative relationship between MTT and the antecedent precipitation index was also found. In other words, wetter antecedent moisture content more rapidly active the fast flow paths. This approach is well suited for constraining process-based modeling in a range of high precipitation intensity and steep relief forested environments.

  3. 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...

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

    DEFF Research Database (Denmark)

    Hansen, Erik Feldager; 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...... correlated significantly (R = 0.88, P measurements. CONCLUSIONS: EUS measures portal venous flow with an acceptable correlation and agreement with TTU in anaesthetized pigs. The method is capable of monitoring the effects......BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler...

  5. Liquid Flow Meter based on a Thermal Anemometer Microsensor

    OpenAIRE

    Oleg Sazhin

    2016-01-01

    An analytical model of a thermal anemometer sensor is developed. A thermal anemometer microsensor utilizing doped polycrystalline silicon is created. A liquid flow meter prototype based on a thermal anemometer microsensor is designed. Results of the flow meter testing are presented.

  6. 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.

  7. Development of a novel vortex flow meter for downhole use

    NARCIS (Netherlands)

    Schiferli, W.; Cheng, L.K.

    2008-01-01

    Due to the increasing complexity of oil and gas wells, the demand for instrumentation to measure conditions inside well tubing below the surface is growing rapidly. A robust meter was designed to measure liquid flows at downhole conditions. The meter is based on a specially-designed bluff body to

  8. 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

    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.......00], p = 0.059) and AUC of 59.9%. There were no significant relationships between TTFM and graft failure in other graft types or graft configurations. CONCLUSION: The TTFM method has good discriminative ability for assessing the risk of graft failure in certain graft types within the first year after...

  9. Self-monitoring ultrasonic gas flow meter

    International Nuclear Information System (INIS)

    Lin, Y; Hans, V

    2005-01-01

    Ultrasound is predestined for gas flow velocity measurements on account of its high sensitivity to all kinds of natural and artificial turbulences in the fluid. Vortex measurements behind a bluff body as well as cross-correlation methods have been proved good. Cross-correlation measurements of natural structures determine the most frequent velocity components in the fluid. Therefore, the measured flow velocity deviates from the real mean flow velocity because of a skewed probability density distribution of the velocity components. Vortex measurements base on the principle that the frequency of the vortices generated in the wake of a bluff body is proportional to the mean flow velocity. The measurement of the periodic vortices with cross-correlation functions leads to the direct determination of the real mean flow velocity. The combination of both measuring methods results in a self-monitoring system

  10. Balanced Flow Metering and Conditioning: Technology for Fluid Systems

    Science.gov (United States)

    Kelley, Anthony R.

    2006-01-01

    Revolutionary new technology that creates balanced conditions across the face of a multi-hole orifice plate has been developed, patented and exclusively licensed for commercialization. This balanced flow technology simultaneously measures mass flow rate, volumetric flow rate, and fluid density with little or no straight pipe run requirements. Initially, the balanced plate was a drop in replacement for a traditional orifice plate, but testing revealed substantially better performance as compared to the orifice plate such as, 10 times better accuracy, 2 times faster (shorter distance) pressure recovery, 15 times less acoustic noise energy generation, and 2.5 times less permanent pressure loss. During 2004 testing at MSFC, testing revealed several configurations of the balanced flow meter that match the accuracy of Venturi meters while having only slightly more permanent pressure loss. However, the balanced meter only requires a 0.25 inch plate and has no upstream or downstream straight pipe requirements. As a fluid conditioning device, the fluid usually reaches fully developed flow within 1 pipe diameter of the balanced conditioning plate. This paper will describe the basic balanced flow metering technology, provide performance details generated by testing to date and provide implementation details along with calculations required for differing degrees of flow metering accuracy.

  11. Development of an Advanced Flow Meter using the Averaging Bi-directional Flow Tube

    Energy Technology Data Exchange (ETDEWEB)

    Baek, W. P.; Yun, B. J.; Kang, K. H.; Uh, D. J.; Chun, S. Y.; Kim, B. D.; Yun, Y. J.; Sung, S. H.; Song, C. H

    2006-01-15

    Advanced flow meter using the concept of averaging bi-directional flow tube was developed. To find characteristics of flow meter and derive theory of measurement in the single and two phase flow condition, some basic tests were attempted using flow meters with diameters of 27, 80 and 200 mm. The CFD(computational fluid dynamics) calculation was also performed to find the effects of temperature and pressure, and to optimize design of a prototypic flow meter. Following this procedure, prototypical flow meters with diameters of 200 and 500 mm were designed and manufactured. It is aimed to use in the region in which calibration constant was unchanged. The stress analysis showed that the proposed flow meter of H-beam shape is inherently strong against the bending force induced by flow. The flow computer was developed for the flow rate calculation from the measured pressure difference. In this study, the performance test using this prototype flow meter was carried out. The developed flow meter can be applied in the wide range of pressure and temperature. The basic tests showed that the lineality of the proposed flow meter is {+-} 0.5 % of full scale and flow turn down ratio is 1:20 where the Reynolds number is larger than 10,000.

  12. How to use your peak flow meter

    Science.gov (United States)

    ... attack . This can tell you how bad your asthma attack is and if your medicine is working. Any ... Make peak flow a habit! Signs of an asthma attack Stay away from asthma triggers Review Date 2/ ...

  13. Vibration isolation for Coriolis Mass-Flow meters

    NARCIS (Netherlands)

    van de Ridder, Bert

    2015-01-01

    A Coriolis Mass-Flow Meter (CMFM) is an active device based on the Coriolis force principle for direct mass-flow measurements, with high accuracy, range-ability and repeatability. The working principle of a CMFM is as follows: a fluid conveying tube is actuated to oscillate at a low amplitude. A

  14. The XCNN flow meter - a combined cross-correlation and neural network model

    International Nuclear Information System (INIS)

    Roverso, Davide

    2004-05-01

    In this report we propose the XCNN flow meter model, which consists of an integration of a cross-correlator (XC) of pressure measurements and an ensemble of neural network (NN) estimators. Since pressure information does not only travel with the fluid, like for example particles, bubbles, eddies and, to a big extent, temperature, but also through the fluid, the transit time of a pressure disturbance estimated by cross-correlation needs to be corrected to take into account the propagation velocity of pressure differentials in the fluid. This correction is performed by the neural network models, which in this case are simple single input single output three layer feed-forward neural networks. Instead of a single neural network an ensemble is used to reduce the variance of the estimate. The proposed method involves several stages where pressure transmitter data is first filtered, then fed to the cross-correlator whose result is interpolated and filtered again before being fed to the ensemble of neural networks, which produce the final flow estimate. An average accuracy of 0.29% (with 0.18 standard deviation) of a reference ultrasonic meter has been obtained on experimental measurements performed at Tecnatom s.a. This report marks the conclusion of the Virtual Sensors for Feedwater Flow Measurement project at the HRP, which run in the 2001-2003 period. (Author)

  15. The impact of flow dynamics in the design of flow meters and metering stations

    NARCIS (Netherlands)

    Bokhorst, E. van; Peters, M.C.A.M.; Braal, F.M.

    2003-01-01

    Commercially available flowmeters are provided with a calibration certificate, based on stationary flow conditions and do not include the impact of installation effects like swirl, a-symmetry, and piping and flow dynamics. Flow pulsations, valve noise and mechanical pipe vibrations can have a

  16. The magnetic flywheel flow meter: Theoretical and experimental contributions

    Science.gov (United States)

    Buchenau, D.; Galindo, V.; Eckert, S.

    2014-06-01

    The development of contactless flow meters is an important issue for monitoring and controlling of processes in different application fields, like metallurgy, liquid metal casting, or cooling systems for nuclear reactors and transmutation machines. Shercliff described in his book "The Theory of Electromagnetic Flow Measurement, Cambridge University Press, 1962" a simple and robust device for contact-less measurements of liquid metal flow rates which is known as magnetic flywheel. The sensor consists of several permanent magnets attached on a rotatable soft iron plate. This arrangement will be placed closely to the liquid metal flow to be measured, so that the field of the permanent magnets penetrates into the fluid volume. The flywheel will be accelerated by a Lorentz force arising from the interaction between the magnetic field and the moving liquid. Steady rotation rates of the flywheel can be taken as a measure for the mean flow rate inside the fluid channel. The present paper provides a detailed theoretical description of the sensor in order to gain a better insight into the functional principle of the magnetic flywheel. Theoretical predictions are confirmed by corresponding laboratory experiments. For that purpose, a laboratory model of such a flow meter was built and tested on a GaInSn-loop under various test conditions.

  17. Coriolis mass flow rate meters for low flows

    NARCIS (Netherlands)

    Mehendale, A.

    2008-01-01

    The accurate and quick measurement of small mass flow rates (~10 mg/s) of fluids is considered an “enabling technology��? in semiconductor, fine-chemical, and food & drugs industries. Flowmeters based on the Coriolis effect offer the most direct sensing of the mass flow rate, and for this reason do

  18. A seepage meter designed for use in flowing water

    Science.gov (United States)

    Rosenberry, D.O.

    2008-01-01

    Seepage meters provide one of the most direct means to measure exchange of water across the sediment-water interface, but they generally have been unsuitable for use in fluvial settings. Although the seepage bag can be placed inside a rigid container to minimize velocity head concerns, the seepage cylinder installed in the sediment bed projects into and disrupts the flow field, altering both the local-scale fluid exchange as well as measurement of that exchange. A low-profile seepage meter designed for use in moving water was tested in a seepage meter flux tank where both current velocity and seepage velocity could be controlled. The conical seepage cylinder protrudes only slightly above the sediment bed and is connected via tubing to a seepage bag or flowmeter positioned inside a rigid shelter that is located nearby where current velocity is much slower. Laboratory and field tests indicate that the net effect of the small protrusion of the seepage cylinder into the surface water flow field is inconsequentially small for surface water currents up to 65 cm s-1. Current velocity affects the variability of seepage measurements; seepage standard deviation increased from ???2 to ???6 cm d-1 as current velocity increased from 9 to 65 cm s-1. Substantial bias can result if the shelter is not placed to minimize hydraulic gradient between the bag and the seepage cylinder.

  19. Compact Mass Flow Meter Based on a Micro Coriolis Flow Sensor

    Directory of Open Access Journals (Sweden)

    Remco Wiegerink

    2013-03-01

    Full Text Available In this paper we demonstrate a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 1 g/h (for water at a pressure drop < 1 bar. It has a zero stability of 2 mg/h and an accuracy of 0.5% reading for both liquids and gases. The temperature drift between 10 and 50 °C is below 1 mg/h/°C. The meter is robust, has standard fluidic connections and can be read out by means of a PC or laptop via USB. Its performance was tested for several common gases (hydrogen, helium, nitrogen, argon and air and liquids (water and isopropanol. As in all Coriolis mass flow meters, the meter is also able to measure the actual density of the medium flowing through the tube. The sensitivity of the measured density is ~1 Hz.m3/kg.

  20. Compact mass flow meter based on a micro Coriolis flow sensor

    NARCIS (Netherlands)

    Sparreboom, Wouter; Katerberg, M.R.; Lammerink, Theodorus S.J.; Postma, F.M.; Haneveld, J.; Groenesteijn, Jarno; Wiegerink, Remco J.; Lötters, Joost Conrad

    2012-01-01

    In this paper we present a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 2 g/h (for water at a pressure drop of 2 bar). It has a zero stability of 2 mg/h and an accuracy of 0.5% reading. The temperature drift between 10 and 50 ºC is below 1 mg/h/ºC. The meter is robust,

  1. Time-of-flight dependency on transducer separation distance in a reflective-path guided-wave ultrasonic flow meter at zero flow conditions.

    Science.gov (United States)

    Aanes, Magne; Kippersund, Remi Andre; Lohne, Kjetil Daae; Frøysa, Kjell-Eivind; Lunde, Per

    2017-08-01

    Transit-time flow meters based on guided ultrasonic wave propagation in the pipe spool have several advantages compared to traditional inline ultrasonic flow metering. The extended interrogation field, obtained by continuous leakage from guided waves traveling in the pipe wall, increases robustness toward entrained particles or gas in the flow. In reflective-path guided-wave ultrasonic flow meters (GW-UFMs), the flow equations are derived from signals propagating solely in the pipe wall and from signals passing twice through the fluid. In addition to the time-of-flight (TOF) through the fluid, the fluid path experiences an additional time delay upon reflection at the opposite pipe wall due to specular and non-specular reflections. The present work investigates the influence of these reflections on the TOF in a reflective-path GW-UFM as a function of transducer separation distance at zero flow conditions. Two models are used to describe the signal propagation through the system: (i) a transient full-wave finite element model, and (ii) a combined plane-wave and ray-tracing model. The study shows that a range-dependent time delay is associated with the reflection of the fluid path, introducing transmitter-receiver distance dependence. Based on these results, the applicability of the flow equations derived using model (ii) is discussed.

  2. Transit time distributions and StorAge Selection functions in a sloping soil lysimeter with time-varying flow paths: Direct observation of internal and external transport variability

    Science.gov (United States)

    Kim, Minseok; Pangle, Luke A.; Cardoso, Charléne; Lora, Marco; Volkmann, Till H. M.; Wang, Yadi; Harman, Ciaran J.; Troch, Peter A.

    2016-09-01

    Transit times through hydrologic systems vary in time, but the nature of that variability is not well understood. Transit times variability was investigated in a 1 m3 sloping lysimeter, representing a simplified model of a hillslope receiving periodic rainfall events for 28 days. Tracer tests were conducted using an experimental protocol that allows time-variable transit time distributions (TTDs) to be calculated from data. Observed TTDs varied with the storage state of the system, and the history of inflows and outflows. We propose that the observed time variability of the TTDs can be decomposed into two parts: "internal" variability associated with changes in the arrangement of, and partitioning between, flow pathways; and "external" variability driven by fluctuations in the flow rate along all flow pathways. These concepts can be defined quantitatively in terms of rank StorAge Selection (rSAS) functions, which is a theory describing lumped transport dynamics. Internal variability is associated with temporal variability in the rSAS function, while external is not. The rSAS function variability was characterized by an "inverse storage effect," whereby younger water is released in greater proportion under wetter conditions than drier. We hypothesize that this effect is caused by the rapid mobilization of water in the unsaturated zone by the rising water table. Common approximations used to model transport dynamics that neglect internal variability were unable to reproduce the observed breakthrough curves accurately. This suggests that internal variability can play an important role in hydrologic transport dynamics, with implications for field data interpretation and modeling.

  3. Arrival-Time Detection and Ultrasonic Flow-Meter Applications

    International Nuclear Information System (INIS)

    Willatzen, Morten; Soendergaard, Peter; Latino, Carl; Voss, Frands; Andersen, Niels Lervad; Brokate, Martin; Bounaim, Aicha

    2006-01-01

    The Danfoss problem on ultrasonic flow measurement has been separated into three parts each handled by a subgroup of the authors listed above. The first subgroup deals with a presentation of modelling equations describing the physics of ultrasonic flow meters employing reciprocal ultrasonic transducer systems. The mathematical model presented allows the electrical output signal to be determined corresponding to any time-dependent electrical input signal. The transducers modelled consist of a piezoceramic material layer and a passive acoustic matching layer. The second subgroup analyzes the possibility of coding the input signal so as to simplify arrival-time detection by re.nding the coded input sequence in the received signal. The narrow-band nature of the transducers makes this problem non-trivial but suggestions for improvement are proposed. The analysis given is based on traditional autoand cross-correlation techniques. The third subgroup attempts to improve existing correlation methods in determining arrival-time detection of signals. A mathematical formulation of the problem is given and the application to a set of real signals provided by Danfoss A/S is performed with good results

  4. Compact mass flow meter based on a micro coriolis flow sensor

    NARCIS (Netherlands)

    Sparreboom, Wouter; van de Geest, Jan; Katerberg, Marcel; Postma, F.M.; Haneveld, J.; Groenesteijn, Jarno; Lammerink, Theodorus S.J.; Wiegerink, Remco J.; Lötters, Joost Conrad

    2013-01-01

    In this paper we demonstrate a compact ready-to-use micro Coriolis mass flow meter. The full scale flow is 1 g/h (for water at a pressure drop < 1 bar). It has a zero stability of 2 mg/h and an accuracy of 0.5% reading for both liquids and gases. The temperature drift between 10 and 50 °C is below 1

  5. Study of Polyurethane Foaming Dynamics Using a Heat Flow Meter

    Science.gov (United States)

    Koniorczyk, P.; Trzyna, M.; Zmywaczyk, J.; Zygmunt, B.; Preiskorn, M.

    2017-05-01

    This work presents the results of the study concerning the effects of fillers addition on the heat flux density \\dot{q}( t ) of foaming of polyurethane-polystyrene porous composite (PSUR) and describes the dynamics of this process during the first 600 s. This foaming process resulted in obtaining porous materials that were based on HFC 365/225 blown rigid polyurethane foam (PUR) matrix, which contained thermoplastic expandable polystyrene (EPS) beads as the filler. In PSUR composites, the EPS beads were expanded after being heated to a temperature above the glass transition temperature of EPS and vaporing gas incorporated inside, by using the heat of exothermic reaction of polyol with isocyanate. From the start (t=0) to the end of the PSUR composite foaming process (t=tk), \\dot{q}( t ) was measured with the use of the heat flow meter. For the purpose of the study two PUR systems were selected: one with high and one with low heat density of foaming process q. EPS beads were selected from the same manufacturer with large and small diameter. The mass fraction of EPS in PSUR foam varied during the measurements. Additionally, a study of volume fractions of expanded EPS phase in PSUR foams as a function of mass fractions of EPS was conducted. In order to verify effects of the EPS addition on the heat flux density during PSUR foaming process, the thermal conductivity measurements were taken.

  6. Exploring the role of mixing between subsurface flow paths on transit time distributions using a Lagrangian model

    Science.gov (United States)

    Zehe, Erwin; Jackisch, Conrad; Rodriguez, Nicolas; Klaus, Julian

    2017-04-01

    Only a minute amount of global fresh water is stored in the unsaturated zone. Yet this tiny compartment controls soil microbial activity and associated trace gas emissions, transport and transformations of contaminants, plant productivity, runoff generation and groundwater recharge. To date, the processes controlling renewal and age of different fractions of the soil water stock are far from being understood. Current theories and process concepts were largely inferred either from over-simplified laboratory experiments, or non-exhaustive point observations and tracer data in the field. Tracer data provide key but yet integrated information about the distribution of travel times of the tracer molecules to a certain depth or on their travel depth distribution within a given time. We hence are able to observe the "effect" of soil structure i.e. partitioning of infiltrating water between fast preferential and slow flow paths and imperfect subsequent mixing between these flow paths in the subsurface and the related plant water uptake. However, we are not able to study the "cause" - because technologies for in-situ observations of flow, flow path topology and exchange processes at relevant interfaces have up to now not been at hand. In the present study we will make use of a Lagrangian model for subsurface water dynamics to explore how subsurface heterogeneity and mixing among different storage fractions affects residence time distribution in the unsaturated zone in a forward approach. Soil water is represented by particles of constant mass, which travel according to the Itô form of the Fokker Planck equation. The model concept builds on established soil physics by estimating the drift velocity and the diffusion term based on the soil water characteristics. The model has been shown to simulate capillary driven soil moisture dynamics in good accordance with a) the Richards equation and b) observed soil moisture data in different soil. The particle model may furthermore

  7. A gas/solids flow metering method based upon differential pressure measurements

    International Nuclear Information System (INIS)

    Shaffer, F.D.; Bajura, R.A.

    1986-01-01

    Experiments were conducted to calibrate a gas/solids mass flow meter which required the measurement of two differential pressures. The metering run consisted of three flow elements: an inlet contraction, a length of straight pipe, and a venturi. The operation of the meter was tested using air and spent fluid cracking catalyst for mass loading ratios (solids/gas) as large as 35:1. Calibration data are presented for a meter utilizing a length of straight pipe and a venturi. Successful operation was attained with other combinations of the three flow elements

  8. 21 CFR 868.1860 - Peak-flow meter for spirometry.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Peak-flow meter for spirometry. 868.1860 Section 868.1860 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... spirometry. (a) Identification. A peak-flow meter for spirometry is a device used to measure a patient's...

  9. 75 FR 42330 - Elemental Mercury Used in Flow Meters, Natural Gas Manometers, and Pyrometers; Significant New...

    Science.gov (United States)

    2010-07-21

    ... Elemental Mercury Used in Flow Meters, Natural Gas Manometers, and Pyrometers; Significant New Use Rule... mercury (CAS No. 7439-97-6) for use in flow meters, natural gas manometers, and pyrometers, except for use... who intend to manufacture (including import) or process elemental mercury for an activity that is...

  10. Inadequate peak expiratory flow meter characteristics detected by a computerised explosive decompression device

    DEFF Research Database (Denmark)

    Miller, M.R.; Atkins, P.R.; Pedersen, O.F.

    2003-01-01

    Methods: The dynamic response of mini-Wright (MW), Vitalograph (V), TruZone (TZ), MultiSpiro (MS) and pneumotachograph (PT) flow meters was tested by delivering two differently shaped flow-time profiles from a computer controlled explosive decompression device fitted with a fast response solenoid.......1) and 257 (39.2), respectively, and at ≈200 l/min they were 51 (23.9) and 1 (0.5). All the meters met ATS accuracy requirements when tested with their waveforms. Conclusions: An improved method for testing the dynamic response of flow meters detects marked overshoot (underdamping) of TZ and MS responses...

  11. Techniques and standards in intraoperative graft verification by transit time flow measurement after coronary artery bypass graft surgery: a critical review.

    Science.gov (United States)

    Niclauss, Lars

    2017-01-01

    Transit time flow measurement (TTFM) is a quality control tool for intraoperative graft evaluation in coronary artery bypass graft (CABG) surgery. A critical review of the literature available using TTFM in CABG surgery is the focus of this article. The main objectives will be to detail precise parameters for flow evaluation, to show limitations of TTFM and to prove its predictive impact on postoperative graft failure rate. Publications listed in the PubMed database were reviewed, searching for intraoperative graft verification in coronary surgery by TTFM, with postoperative imaging follow-up (FU) modality and with a special focus on publications released after European guidelines from 2010. Nine included publications revealed an overall graft failure rate of ∼12%. Mean graft flow had a positive predictive value in the largest study, and cut-offs, of at least 20 ml/min for internal mammary artery (IMA) grafts, therein partially confirming guidelines, and 30-40 ml/min for saphenous venous grafts (SVGs) were proposed. An explicit correlation between graft flow, patency rate and severity of coronary stenosis, by indicating the fractional flow reserve, was found for IMA grafts. Increased pulsatility index and increased systolic reverse flow probably predict worse outcome and may help identifying competitive flow. Diastolic filling, rarely indicated, could not be confirmed as the predictive marker. No significant correlation of TTFM and graft failure rate for radial and other arterial grafts could be found, partially due to the small number of these types of grafts analysed. Larger target vessels and lower postoperative CK-MB levels may predict better graft patency rates. Low sensitivity for TTFM to reliably detect graft failure is certainly a major issue, as found in randomized analyses. However, methodical limitations and varying threshold values for TTFM render a general consensus difficult. Influence of quantity (vessel territory distribution) and quality

  12. Predicting Extubation Outcome by Cough Peak Flow Measured Using a Built-in Ventilator Flow Meter.

    Science.gov (United States)

    Gobert, Florent; Yonis, Hodane; Tapponnier, Romain; Fernandez, Raul; Labaune, Marie-Aude; Burle, Jean-François; Barbier, Jack; Vincent, Bernard; Cleyet, Maria; Richard, Jean-Christophe; Guérin, Claude

    2017-12-01

    Successful weaning from mechanical ventilation depends on the patient's ability to cough efficiently. Cough peak flow (CPF) could predict extubation success using a dedicated flow meter but required patient disconnection. We aimed to predict extubation outcome using an overall model, including cough performance assessed by a ventilator flow meter. This was a prospective observational study conducted from November 2014 to October 2015. Before and after a spontaneous breathing trial, subjects were encouraged to cough as strongly as possible before freezing the ventilator screen to assess CPF and tidal volume (V T ) in the preceding inspiration. Early extubation success rate was defined as the proportion of subjects not re-intubated 48 h after extubation. Diagnostic performance of CPF and V T was assessed by using the area under the curve of the receiver operating characteristic curve. Cut-off values for CPF and V T were defined according to median values and used to describe the performance of a predictive test combining them with risk factors of early extubation failure. Among 673 subjects admitted, 92 had a cough assessment before extubation. For the 81 subjects with early extubation success, the median CPF was -67.7 L/min, and median V T was 0.646 L. For the 11 subjects with early extubation failure, the median CPF was -57.3 L/min, and median V T was 0.448 L. Area under the curve was 0.61 (95% CI 0.37-0.83) for CPF and 0.64 (95% CI 0.42-0.84) for CPF/V T combined. After dichotomization (CPF 0.55 L), there was a synergistic effect to predict early extubation success ( P pH before extubation meter of an ICU ventilator was able to predict extubation success and to build a composite score to predict extubation failure. The results were close to that found in previous studies that used a dedicated flow meter. This could help to identify high-risk subjects to prevent extubation failure. (ClinicalTrials.gov registration NCT02847221.). Copyright © 2017 by Daedalus

  13. 40 CFR 1065.640 - Flow meter calibration calculations.

    Science.gov (United States)

    2010-07-01

    ... temperature of the flow rate. R = molar gas constant. M mix = molar mass of the flow rate. Example 1: V stdref...). These governing equations assume one-dimensional isentropic inviscid compressible flow of an ideal gas... ideal gas, the governing equations include a first-order correction for the behavior of a real gas...

  14. Unbalanced-flow, fluid-mixing plug with metering capabilities

    Science.gov (United States)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Van Buskirk, Paul D. (Inventor)

    2009-01-01

    A fluid mixer plug has holes formed therethrough such that a remaining portion is closed to fluid flow. The plug's inlet face defines a central circuit region and a ring-shaped region with the ring-shaped region including at least some of the plug's remaining portion so-closed to fluid flow. This remaining portion or closed region at each radius R of the ring shaped region satisfies a radius independent, flow-based relationship. Entry openings are defined in the plug's inlet face in correspondence with the holes. The entry openings define an open flow area at each radius of the ring-shaped region. The open flow area at each such radius satisfies the inverse of the flow-based relationship defining the closed regions of the plug.

  15. Design and construction of two phases flow meter

    International Nuclear Information System (INIS)

    Nor Paiza Mohamad Hasan

    2002-01-01

    This paper deals with design of the gamma ray correlometer and flow loop system for measuring the velocity between two parallel cross-sections of a pipeline. In the laboratory, the radioisotope source and detector were collimated by brass with small beam slit respectively. The flow loop system consists of transparent pipeline, adjustable frequency pump and water container. As a result, when the construction of the flow loop and correlometer is completed, the velocity of two phases flow can be measured by the cross-correlation techniques. (Author)

  16. Development and evaluation of a meter for measuring return line fluid flow rates during drilling

    Energy Technology Data Exchange (ETDEWEB)

    Loeppke, G.E.; Schafer, D.M.; Glowka, D.A.; Scott, D.D.; Wernig, M.D. (Sandia National Labs., Albuquerque, NM (United States)); Wright, E.K. (Ktech Corp., Albuquerque, NM (United States))

    1992-06-01

    The most costly problem routinely encountered in geothermal drilling is lost circulation, which occurs when drilling fluid is lost to the formation rather than circulating back to the surface. The successful and economical treatment of lost circulation requires the accurate measurement of drilling fluid flow rate both into and out of the well. This report documents the development of a meter for measuring drilling fluid outflow rates in the return line of a drilling rig. The meter employs a rolling counterbalanced float that rides on the surface of the fluid in the return line. The angle of the float pivot arm is sensed with a pendulum potentiometer, and the height of the float is calculated from this measurement. The float height is closely related to the fluid height and, therefore, the flow rate in the line. The prototype rolling float meter was extensively tested under laboratory conditions in the Wellbore Hydraulics Flow Facility; results from these tests were used in the design of the field prototype rolling float meter. The field prototype meter was tested under actual drilling conditions in August and September 1991 at the Long Valley Exploratory Well near Mammoth Lakes, Ca. In addition, the performance of several other commercially available inflow and outflow meters was evaluated in the field. The tested inflow meters included conventional pump stroke counters, rotary pump speed counters, magnetic flowmeters, and an ultrasonic Doppler flowmeter. On the return flow line, a standard paddlemeter, an acoustic level meter, and the prototype rolling float meter were evaluated for measuring drilling fluid outflow rates.

  17. 40 CFR 1065.230 - Raw exhaust flow meter.

    Science.gov (United States)

    2010-07-01

    ... a chemical-balance calculation to determine work from brake-specific fuel consumption and fuel... exhaust's thermodynamic, fluid, and compositional states. (c) Flow conditioning. For any type of raw...

  18. Impedance void-meter and neural networks for vertical two-phase flows

    International Nuclear Information System (INIS)

    Mi, Y.; Li, M.; Xiao, Z.; Tsoukalas, L.H.; Ishii, M.

    1998-01-01

    Most two-phase flow measurements, including void fraction measurements, depend on correct flow regime identification. There are two steps towards successful identification of flow regimes: one is to develop a non-intrusive instrument to demonstrate area-averaged void fluctuations, the other to develop a non-linear mapping approach to perform objective identification of flow regimes. A non-intrusive impedance void-meter provides input signals to a neural mapping approach used to identify flow regimes. After training, both supervised and self-organizing neural network learning paradigms performed flow regime identification successfully. The methodology presented holds considerable promise for multiphase flow diagnostic and measurement applications. (author)

  19. Coriolis mass flow meter using contactless excitation and detection

    NARCIS (Netherlands)

    Mehendale, A.; Lotters, Joost Conrad; Lötters, Joost Conrad; Zwikker, Jan Marinus

    2006-01-01

    A mass flowmeter of the Coriolis type with a tube through which a medium flows during operation and with excitation means for causing the entire tube or part thereof to perform a rotational vibration about a primary axis of rotation during operation. The excitation means are electromagnetic and

  20. Feasibility Study of Power Uprate Using Ultrasonic Flow Meters in NPPs

    International Nuclear Information System (INIS)

    Kim, Tae Mi; Heo, Gyun Young

    2010-01-01

    Feedwater flowrate is an important input parameter in establishing the plant's operating power level. In Korean nuclear power plants, venturi flow meters have been used for measuring the feedwater flow of the secondary side. However, as time goes on, the fouling in venture meters could cause measurement uncertainties to grow and that could lead to operation at less than about 2% of the licensed thermal power limit. In order to resolve the problem, nuclear power plants in other countries use Ultrasonic Flow Meters (UFMs) which have relatively lower measurement uncertainty (about 0.5%) instead of venturi flow meters and have reduced the errors from the fouling in venturi-type flow meters. USA amended 10 CFR 50 Appendix K so that US nuclear power plants can use real value of Core Operating Limit Supervisory System (COLSS) uncertainty, which is currently fixed as 2%, by adopting the UFM. Korea also has been amended the law in order to get benefits from the technology. In this study, we are going to present the fundamental principles of UFMs and the advantages and disadvantages of its installation. Also, we inquire into the conventional uses of UFMs in the overseas sites and then check what is needed to consider for its domestic application

  1. 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

  2. Numerical Simulation Modelling for Velocity Measurement of Electromagnetic Flow Meter

    International Nuclear Information System (INIS)

    Wang, J Z; Gong, C L; Tian, G Y; Lucas, G P

    2006-01-01

    An induced voltage EMF in the area of measuring single-phase flow rate in pipes has been used in many industrial areas. To measure the continuous phase velocity profile in multiphase flows where the continuous phase is an electrical conductor, Electrical capacitance and resistance tomography has been comprehensively investigated, except for continuous phase velocity profile measurement. This paper tries to design the numerical simulation model according to the basic electromagnetic induction law and to investigate the relationship between induced electric potential or potential drop and the velocity distribution of the conductive continuous phase in the flow. First, the 3-Dimenssion simulating module for EMF is built. Given the most simple velocity profile of the fluid in the pipe, the value of the induced potential difference between electrodes is obtained by simulation and theoretical computation according to J A Shercliff's weight function. The relative error is 6.066 . This proves that the simulation model is accurate enough to investigate the characteristic of the induced potential difference of EMF. Finally, the relationship between induced potential difference and the velocity profile is analysed in detail where the complicated velocity profile is expressed as vz = 1m/s when 0.022< x2+y2< = 0.02652 and vz = 5m/s when x2+y2< = 0.022

  3. Microcomputer-controlled flow meter used on a water loop

    International Nuclear Information System (INIS)

    Haniger, L.

    1982-01-01

    The report describes a microcomputer-controlled instrument intended for operational measurement on an experimental water loop. On the basis of pressure and temperature input signals the instrument calculates the specific weight, and for ten operator-selectable measuring channels it calculates the mass flow G(kp/s), or the voluminal flow Q(m 3 /h). On pressing the appropriate push-buttons the built-in display indicates the values of pressure (p) and temperature (t), as well as the values of specific weight γ calculated therefrom. For ten individually selectable channels the instrument displays either the values of the pressure differences of the measuring throttling elements (√Δpsub(i)), or the values of Gsub(i) or Qsub(i) as obtained by calculation. In addition, on pressing the Σ-push-button it summarizes the values of Gsub(i) and Qsub(i) for the selected channels. The device is controlled by an 8085 microprocessor, the analog unit MP 6812 being used as the A/D convertor. The instrument algorithm indicates some possible errors which may concern faults of input signals or mistakes in calculation. (author)

  4. A Self-diagnostic Method for the Electrode Adhesion of an Electromagnetic Flow-meter

    Directory of Open Access Journals (Sweden)

    Wen-Hua Cui

    2014-07-01

    Full Text Available Electrodes of electromagnetic flow-meter are subject to contamination in sewage measurement. In this paper, the relationship between the internal resistance of the flow-induced voltage and the electrode contamination is analyzed on the basis of numerical analysis. A new self- diagnostic method for electrode adhesion with additional excitation based on photovoltaic cell is proposed, in which magnetic excitation for flow-rate measurement and electric excitation for electrode self-diagnosis is divided in both time domain and frequency domain. A dual-excited electromagnetic flow-meter with electrode self-diagnosis was designed and validated. Simulation experiments based on the change of the internal resistance of the flow-induced voltage were carried out. And the experimental results fully show that this new method is feasible and promising.

  5. Experimental Investigation of the Performance of Tilt Current Meters in Wave-Dominated Flows

    DEFF Research Database (Denmark)

    Hansen, Asger Bendix; Carstensen, Stefan

    2017-01-01

    In recent years, tilt current meters (TCMs) have received renewed attention as they provide an inexpensive method for measuring currents in the coastal zone. However, previous studies focused mainly on current dominated flows or the current component of the flow. This study investigates the perfo......In recent years, tilt current meters (TCMs) have received renewed attention as they provide an inexpensive method for measuring currents in the coastal zone. However, previous studies focused mainly on current dominated flows or the current component of the flow. This study investigates...... TCMs were investigated in order to assess the effect of TCM shape on its performance. The measured TCM tilt is compared with the flow velocity measured by conventional methods. Furthermore, the ability of a TCM to measure wave orbital and wave-averaged velocities is discussed....

  6. Electromagnetic Flow Meter Having a Driver Circuit Including a Current Transducer

    Science.gov (United States)

    Karon, David M. (Inventor); Cushing, Vincent (Inventor); Patel, Sandeep K. (Inventor)

    2014-01-01

    An electromagnetic flow meter (EMFM) accurately measures both the complete flow rate and the dynamically fluctuating flow rate of a fluid by applying a unipolar DC voltage to excitation coils for a predetermined period of time, measuring the electric potential at a pair of electrodes, determining a complete flow rate and independently measuring the dynamic flow rate during the "on" cycle of the DC excitation, and correcting the measurements for errors resulting from galvanic drift and other effects on the electric potential. The EMFM can also correct for effects from the excitation circuit induced during operation of the EMFM.

  7. COMPUTER-AIDED FLOW METER APPLICABLE TO LOOSE MATERIALS IN THE COURSE OF PNEUMATIC TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    Gulyaev Valeriy Genrihovich

    2012-07-01

    Full Text Available The article covers the issues of development and the results of the pilot testing of the contact-free meter of the two-phase flow of loose construction materials in the course of their pneumatic transportation. The flow meter designed by the author is based on the method of registration of polarization currents caused by the motion of the dielectric material within the electric field of a measurement unit integrated into the pneumatic transportation line. The registration unit is the implementation of the original technology. Its functional concept is based on the Pockels transverse effect inside the lithium niobate crystal. This electro-optical effect is characterized by minimal persistence, as the phase of the optical wave varies within the time period of 10 second, and this effect makes it possible to improve the accuracy of measurements. The flow rates is identified on the basis of one variable integral parameter, the intensity of an optical wave passing through the Pockels cell simulated by the currents of polarization of the material. The paper contains the structural pattern of the computer-aided meter of loose dielectric materials in the course of their pneumatic transportation, the system of visualization of the mass flow, and the results of the pilot testing of the proposed meter. The proposed system may represent an unbiased system of management of construction materials, consumption procedures, and warehouse processing of materials.

  8. Vibration Isolation by an Actively Compliantly Mounted Sensor Applied to a Coriolis Mass-Flow Meter

    NARCIS (Netherlands)

    van de Ridder, Bert; Hakvoort, Wouter; van Dijk, Johannes; Lötters, Joost Conrad; de Boer, Andries

    2016-01-01

    In this paper, a vibration isolated design of a Coriolis mass-flow meter (CMFM) is proposed by introducing a compliant connection between the casing and the tube displacement sensors, with the objective to obtain a relative displacement measurement of the fluid conveying tube, dependent on the tube

  9. The use of a low-cost gas-liquid flow meter to monitor severe slugging

    DEFF Research Database (Denmark)

    Andreussi, Paolo; Bonizzi, Marco; Ciandri, Paolo

    2017-01-01

    method to monitor severe slugging by means of low cost instrumentation, in particular, by replacing a cumbersome instrument such as a gamma-densitometer with a differential pressure transmitter. In field operation, the multiphase orifice used in these experiments can be replaced by a calibrated control......A very simple, low-cost gas-liquid flow meter that only employs conventional field instrumentation has been used to monitor severe slugging occurring at the exit of a vertical pipe. This meter was originally developed for conventional oil field applications [1] and is based on the readings...

  10. Application of Data Smoothing Method in Signal Processing for Vortex Flow Meters

    Directory of Open Access Journals (Sweden)

    Zhang Jun

    2017-01-01

    Full Text Available Vortex flow meter is typical flow measure equipment. Its measurement output signals can easily be impaired by environmental conditions. In order to obtain an improved estimate of the time-averaged velocity from the vortex flow meter, a signal filter method is applied in this paper. The method is based on a simple Savitzky-Golay smoothing filter algorithm. According with the algorithm, a numerical program is developed in Python with the scientific library numerical Numpy. Two sample data sets are processed through the program. The results demonstrate that the processed data is available accepted compared with the original data. The improved data of the time-averaged velocity is obtained within smoothing curves. Finally the simple data smoothing program is useable and stable for this filter.

  11. Investigated conductive fracture in the granitic rocks by flow-meter logging

    International Nuclear Information System (INIS)

    Ogata, Nobuhisa; Koide, Kaoru; Takeichi, Atsushi

    1997-01-01

    Test of the use of a measurement technique for the hydraulic conductivity of geological structures which act as flow paths or are impermeable to groundwater flow. In order to prove the value of flow-meter logging as an in-situ technique for detecting conductive fractures in granitic rocks, the method has been applied to a borehole near the Tono uranium mine, Gifu, Japan. This study in involved with detecting a conductive fracture and calculating the hydraulic conductivities. The results were as follows: (1) In a zone of groundwater inflow into the borehole, the hydraulic conductivity was calculated to be of the order of the 10 -3 - 10 -4 (cm/sec) from flow-meter logging. This value agreed with the results of a in-situ borehole permeability test carried out with a similar depth interval. (2) The study showed that flow-meter logging is effective for detecting the distribution of high conductivity fractures and calculating the hydraulic conductivity. (author)

  12. Influence of the operating pressure in flow metering systems using turbine meters-key factors; Influencia da pressao em sistemas de medicao de gas natural com totalizadores de volume do tipo turbina: fatores a considerar

    Energy Technology Data Exchange (ETDEWEB)

    Wilcek, Alanna; Picanco, Marco Antonio S. [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil)

    2008-07-01

    Flow measurement is a strategic process in the Natural Gas transport and distribution industry. The diary measurement of the 43 million cubic meters consumed in Brazil is made by flow meters certified by the Rede Brasileira de Calibracao (Brazilian Calibration Network) and INMETRO. Turbine flow meters are commonly applied in high flow measurement systems. Some manufactures and authors discuss the sensibility of turbine meters to the operational conditions. The objective of this paper is to establish a discussion about the flow pressure effects in the turbine meter and the influence in measure errors. (author)

  13. Methods of measurement signal acquisition from the rotational flow meter for frequency analysis

    Directory of Open Access Journals (Sweden)

    Świsulski Dariusz

    2017-01-01

    Full Text Available One of the simplest and commonly used instruments for measuring the flow of homogeneous substances is the rotational flow meter. The main part of such a device is a rotor (vane or screw rotating at a speed which is the function of the fluid or gas flow rate. A pulse signal with a frequency proportional to the speed of the rotor is obtained at the sensor output. For measurements in dynamic conditions, a variable interval between pulses prohibits the analysis of the measuring signal. Therefore, the authors of the article developed a method involving the determination of measured values on the basis of the last inter-pulse interval preceding the moment designated by the timing generator. For larger changes of the measured value at a predetermined time, the value can be determined by means of extrapolation of the two adjacent interpulse ranges, assuming a linear change in the flow. The proposed methods allow analysis which requires constant spacing between measurements, allowing for an analysis of the dynamics of changes in the test flow, eg. using a Fourier transform. To present the advantages of these methods simulations of flow measurement were carried out with a DRH-1140 rotor flow meter from the company Kobold.

  14. A prototype of on-line digital flow rate meter based on cross-correlation principle

    International Nuclear Information System (INIS)

    Sun Xiaodong; Dai Zhenxi; Xu Jijun

    1997-01-01

    An on-line, digital prototype of flow rate measurement system based on cross-correlation principle is developed. Laboratory measurements using the prototype show that sufficiently large temperature fluctuations exist naturally and that measurements are possible. Temperature fluctuations are detected by two identical thermocouples spaced along the flow direction and are pre-processed by a thermocouple signal amplifier. The pre-processed temperature fluctuations are analyzed by a cross-correlator which measures the transit time of temperature fluctuations between two thermocouples directly. Thus, the so-called correlation velocity can be determined by a chip microprocessor 8031. Experimental results with single-phase under steady conditions also show that the distance between two thermocouples and the Reynolds number of fluid are the most important parameters to the measurement

  15. A combined ultrasonic flow meter and binary vapour mixture analyzer for the ATLAS silicon tracker

    CERN Document Server

    Bates, R; Berry, S; Berthoud, J; Bitadze, A; Bonneau, P; Botelho-Direito, J; Bousson, N; Boyd, G; Bozza, G; Da Riva, E; Degeorge, C; DiGirolamo, B; Doubek, M; Giugni, D; Godlewski, J; Hallewell, G; Katunin, S; Lombard, D; Mathieu, M; McMahon, S; Nagai, K; Perez-Rodriguez, E; Rossi, C; Rozanov, A; Vacek, V; Vitek, M; Zwalinski, L

    2013-01-01

    An upgrade to the ATLAS silicon tracker cooling control system may require a change from C3F8 (octafluoro-propane) evaporative coolant to a blend containing 10-25% of C2F6 (hexafluoro-ethane). Such a change will reduce the evaporation temperature to assure thermal stability following radiation damage accumulated at full LHC luminosity. Central to this upgrade is a new ultrasonic instrument in which sound transit times are continuously measured in opposite directions in flowing gas at known temperature and pressure to deduce the C3F8/C2F6 flow rate and mixture composition. The instrument and its Supervisory, Control and Data Acquisition (SCADA) software are described in this paper. Several geometries for the instrument are in use or under evaluation. An instrument with a pinched axial geometry intended for analysis and measurement of moderate flow rates has demonstrated a mixture resolution of 3.10-3 for C3F8/C2F6 molar mixtures with 20%C2F6, and a flow resolution of 2% of full scale for mass flows up to 30gs-...

  16. Numerical simulation of the effect of upstream swirling flow on swirl meter performance

    Science.gov (United States)

    Chen, Desheng; Cui, Baoling; Zhu, Zuchao

    2018-04-01

    Flow measurement is important in the fluid process and transmission system. For the need of accuracy measurement of fluid, stable flow is acquired. However, the elbows and devices as valves and rotary machines may produce swirling flow in the natural gas pipeline networks system and many other industry fields. In order to reveal the influence of upstream swirling flow on internal flow fields and the metrological characteristics, numerical simulations are carried out on the swirl meter. Using RNG k-ɛ turbulent model and SIMPLE algorithm, the flow field is numerically simulated under swirling flows generated from co-swirl and counter-swirl flow. Simulation results show fluctuation is enhanced or weakened depending on the rotating direction of swirling flow. A counter- swirl flow increases the entropy production rate at the inlet and outlet of the swirler, the junction region between throat and divergent section, and then the pressure loss is increased. The vortex precession dominates the static pressure distributions on the solid walls and in the channel, especially at the end region of the throat.

  17. Energy Harvesting from Fluid Flow in Water Pipelines for Smart Metering Applications

    International Nuclear Information System (INIS)

    Hoffmann, D; Willmann, A; Göpfert, R; Becker, P; Folkmer, B; Manoli, Y

    2013-01-01

    In this paper a rotational, radial-flux energy harvester incorporating a three-phase generation principle is presented for converting energy from water flow in domestic water pipelines. The energy harvester together with a power management circuit and energy storage is used to power a smart metering system installed underground making it independent from external power supplies or depleting batteries. The design of the radial-flux energy harvester is adapted to the housing of a conventional mechanical water flow meter enabling the use of standard components such as housing and impeller. The energy harvester is able to generate up to 720 mW when using a flow rate of 20 l/min (fully opened water tab). A minimum flow rate of 3 l/min is required to get the harvester started. In this case a power output of 2 mW is achievable. By further design optimization of the mechanical structure including the impeller and magnetic circuit the threshold flow rate can be further reduced

  18. Energy Harvesting from Fluid Flow in Water Pipelines for Smart Metering Applications

    Science.gov (United States)

    Hoffmann, D.; Willmann, A.; Göpfert, R.; Becker, P.; Folkmer, B.; Manoli, Y.

    2013-12-01

    In this paper a rotational, radial-flux energy harvester incorporating a three-phase generation principle is presented for converting energy from water flow in domestic water pipelines. The energy harvester together with a power management circuit and energy storage is used to power a smart metering system installed underground making it independent from external power supplies or depleting batteries. The design of the radial-flux energy harvester is adapted to the housing of a conventional mechanical water flow meter enabling the use of standard components such as housing and impeller. The energy harvester is able to generate up to 720 mW when using a flow rate of 20 l/min (fully opened water tab). A minimum flow rate of 3 l/min is required to get the harvester started. In this case a power output of 2 mW is achievable. By further design optimization of the mechanical structure including the impeller and magnetic circuit the threshold flow rate can be further reduced.

  19. 40 CFR 86.120-94 - Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement.

    Science.gov (United States)

    2010-07-01

    ... calibration; particulate, methanol and formaldehyde measurement. 86.120-94 Section 86.120-94 Protection of... Procedures § 86.120-94 Gas meter or flow instrumentation calibration; particulate, methanol and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters...

  20. Efficacy of the ejector flow-meter. A scavenging device for anaesthetic gases

    Energy Technology Data Exchange (ETDEWEB)

    Obel, D.; Jorgensen, S.; Ferguson, A.; Frandsen, K.

    1985-01-01

    Measurements of air concentrations of nitrous oxide and halothane in the breathing zone of the anaesthetist and the operating-room nurse were carried out during inhalation anaesthesia with a Mapleson D system. Gas removal was performed from inside the breathing system at the same rate as that of the fresh gas inflow by means of an ejector flow-meter. The concentrations of nitrous oxide and halothane were maintained below the Danish Threshold Limit Values of 100 and 5 parts per million, respectively, by using this type of scavenging. When these anaesthetics were used simultaneously, the reduced Threshold Limit Values were not exceeded during endotracheal anaesthesia.

  1. Experimental Study on Performance of Turbine Flowmeter and Venturi Meter in Oil-Water Two-Phase Flow Measurement

    Science.gov (United States)

    Huang, Zhiyao; Li, Xia; Liu, Yian; Wang, Baoliang; Li, Haiqing

    2007-06-01

    The performance of turbine flowmeter and Venturi meter in oil-water two-phase flow measurement was investigated. Experiments were carried out on horizontal pipelines of 0.5-inch, 1.0-inch and 1.5-inch diameters, with the total flowrate range of 0.9˜4.5m3/h and the oil volume fraction range of 15% ˜ 85%. Experimental results show that the measurement errors of the turbine flowmeter and the Venturi meter obviously increase, whether the static mixer is installed on the experimental loop or not. Also, the non-homogeneity of the oil-water two-phase flow and the swirl flow produced by the static mixer have negative influence on the performance of turbine flowmeter and Venturi meter. Research work further indicates that the oil fraction has significant influence on the measurement results of Venturi meter.

  2. Imposed Work of Breathing for Flow Meters with In-Line versus Flow-Through Technique during Simulated Neonatal Breathing.

    Directory of Open Access Journals (Sweden)

    Snorri Donaldsson

    Full Text Available The ability to determine airflow during nasal CPAP (NCPAP treatment without adding dead space or resistance would be useful when investigating the physiologic effects of different NCPAP systems on breathing. The aim of this study was to investigate the effect on pressure stability of different flow measuring devices at the in-line and flow-through position, using simulated neonatal breathing.Six different flow measure devices were evaluated by recording pressure changes and imposed work of breathing for breaths with 16 and 32 ml tidal volumes. The tests were performed initially with the devices in an in line position and with 5 and 10 L/min using flow through technique, without CPAP. The flow meters were then subsequently tested with an Infant Flow CPAP system at 3, 5 and 8 cm H2O pressure using flow through technique. The quality of the recorded signals was compared graphically.The resistance of the measuring devices generated pressure swings and imposed work of breathing. With bias flow, the resistance also generated CPAP pressure. Three of the devices had low resistance and generated no changes in pressure stability or CPAP pressure. The two devices intended for neonatal use had the highest measured resistance.The importance of pressure stability and increased work of breathing during non-invasive respiratory support are insufficiently studied. Clinical trials using flow-through technique have not focused on pressure stability. Our results indicate that a flow-through technique might be a way forward in obtaining a sufficiently high signal quality without the added effects of rebreathing and increased work of breathing. The results should stimulate further research and the development of equipment for dynamic flow measurements in neonates.

  3. Metering the capillary-driven flow of fluids in paper-based microfluidic devices.

    Science.gov (United States)

    Noh, Hyeran; Phillips, Scott T

    2010-05-15

    This article describes an exceedingly simple and low-cost method for metering the capillary-driven flow rate of fluids within three-dimensional (3D) microfluidic, paper-based analytical devices (microPADs). Initial prototypes of 3D microPADs control the spatial distribution of fluids within a device, but they provide little control over how quickly (or slowly) fluids move within the device. The methods described in this article provide control over when and how quickly a fluid is distributed into detection zones. These methods are inexpensive (the metering regions are composed of paraffin wax), the devices are easy to fabricate, and they are capable of controlling the flow of fluids to detection zones with precise time delays (e.g., +/-6% of the total wicking time). We anticipate that this type of precise control over fluid distribution rates will be useful particularly for point-of-care assays that require multiple steps (where each step requires that the reagents interact for a defined period of time) or for simultaneously displaying the results of multiple different assays on a single device.

  4. A Novel Method of Multi-Information Acquisition for Electromagnetic Flow Meters

    Directory of Open Access Journals (Sweden)

    Wenhua Cui

    2015-12-01

    Full Text Available In this paper, a novel method is proposed for multi-information acquisition from the electromagnetic flow meter, using magnetic excitation to measure the fluid velocity and electrochemistry impedance spectroscopy (EIS for both the fluid quality and the contamination level of the transducer. The impedance spectra of the transducer are measured with an additional electrical stimulus in series with the electrode measurement loop. The series connection mode instead of the parallel one improves the signal-to-noise ratio (SNR of the fluid velocity measurement and offers a wide range of impedance measurements by using a sample capacitance. In addition, a multi-frequency synchronous excitation source is synthesized based on the method of dual-base power sequences for fast EIS measurement. The conductivity measurements in the range of 1.7 μS/cm–2 mS/cm showed a relatively high accuracy with a measurement error of 5%, and the electrode adhesion detection on both with coating and no coating showed the ability of the qualitative determination of the electrode adhesion, which validated the feasibility of the multi-information acquisition method for the electromagnetic flow meter (EMFM.

  5. A Novel Method of Multi-Information Acquisition for Electromagnetic Flow Meters.

    Science.gov (United States)

    Cui, Wenhua; Li, Bin; Chen, Jie; Li, Xinwei

    2015-12-26

    In this paper, a novel method is proposed for multi-information acquisition from the electromagnetic flow meter, using magnetic excitation to measure the fluid velocity and electrochemistry impedance spectroscopy (EIS) for both the fluid quality and the contamination level of the transducer. The impedance spectra of the transducer are measured with an additional electrical stimulus in series with the electrode measurement loop. The series connection mode instead of the parallel one improves the signal-to-noise ratio (SNR) of the fluid velocity measurement and offers a wide range of impedance measurements by using a sample capacitance. In addition, a multi-frequency synchronous excitation source is synthesized based on the method of dual-base power sequences for fast EIS measurement. The conductivity measurements in the range of 1.7 μS/cm-2 mS/cm showed a relatively high accuracy with a measurement error of 5%, and the electrode adhesion detection on both with coating and no coating showed the ability of the qualitative determination of the electrode adhesion, which validated the feasibility of the multi-information acquisition method for the electromagnetic flow meter (EMFM).

  6. 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...

  7. Quantitative estimation of the influence of external vibrations on the measurement error of a coriolis mass-flow meter

    NARCIS (Netherlands)

    van de Ridder, Bert; Hakvoort, Wouter; van Dijk, Johannes; Lötters, Joost Conrad; de Boer, Andries; Dimitrovova, Z.; de Almeida, J.R.

    2013-01-01

    In this paper the quantitative influence of external vibrations on the measurement value of a Coriolis Mass-Flow Meter for low flows is investigated, with the eventual goal to reduce the influence of vibrations. Model results are compared with experimental results to improve the knowledge on how

  8. Clean water billing monitoring system using flow liquid meter sensor and SMS gateway

    Science.gov (United States)

    Fahmi, F.; Hizriadi, A.; Khairani, F.; Andayani, U.; Siregar, B.

    2018-03-01

    Public clean water company (PDAM) as a public service is designed and organized to meet the needs of the community. Currently, the number of PDAM subscribers is very big and will continue to grow, but the service and facilities to customers are still done conventionally by visiting the customer’s home to record the last position of the meter. One of the problems of PDAM is the lack of disclosure of PDAM customers’ invoice because it is only done monthly. This, of course, makes PDAM customers difficult to remember the date of payment of water account. Therefore it is difficult to maintain the efficiency. The purpose of this research is to facilitate customers of PDAM water users to know the details of water usage and the time of payment of water bills easily. It also facilitates customers in knowing information related to the form of water discharge data used, payment rates, and time grace payments using SMS Gateway. In this study, Flow Liquid Meter Sensor was used for data retrieval of water flowing in the piping system. Sensors used to require the help of Hall Effect sensor that serves to measure the speed of water discharge and placed on the pipe that has the same diameter size with the sensor diameter. The sensor will take the data from the rate of water discharge it passes; this data is the number of turns of the mill on the sensor. The results of the tests show that the built system works well in helping customers know in detail the amount of water usage in a month and the bill to be paid

  9. Internal Flow and Near-Orifice Spray Visualisations of a Model Pharmaceutical Pressurised Metered Dose Inhaler

    International Nuclear Information System (INIS)

    Versteeg, H K; Hargrave, G K; Kirby, M

    2006-01-01

    The pressurised Metered Dose Inhaler (pMDI) has become the most prescribed drug delivery system for treating the respiratory diseases. However, the spray generation mechanism of these devices has not been extensively researched and there is very little information regarding the two-phase fluid dynamics associated with pre-atomisation inside the valve stem. The aim of the work presented in this paper is to provide high-quality, time-resolved imaging of the internal flow structures of pMDIs in an attempt to link the characteristics of the internal flow to external spray atomization processes. Visualisations of the aerosols in the near-orifice region findings from previous studies of commercial pMDIs and showed the following characteristics: (i) start-up transient (ii) fully developed spray with slow spray density variations and (iii) rapid spray density pulsations with large droplet production. The results clearly highlighted the potential of optical diagnostics in the development of improved accounts of the state of the flow inside a pMDI valve and its relationship with drop formation

  10. Water Pipeline Monitoring and Leak Detection using Flow Liquid Meter Sensor

    Science.gov (United States)

    Rahmat, R. F.; Satria, I. S.; Siregar, B.; Budiarto, R.

    2017-04-01

    Water distribution is generally installed through underground pipes. Monitoring the underground water pipelines is more difficult than monitoring the water pipelines located on the ground in open space. This situation will cause a permanent loss if there is a disturbance in the pipeline such as leakage. Leaks in pipes can be caused by several factors, such as the pipe’s age, improper installation, and natural disasters. Therefore, a solution is required to detect and to determine the location of the damage when there is a leak. The detection of the leak location will use fluid mechanics and kinematics physics based on harness water flow rate data obtained using flow liquid meter sensor and Arduino UNO as a microcontroller. The results show that the proposed method is able to work stably to determine the location of the leak which has a maximum distance of 2 metres, and it’s able to determine the leak location as close as possible with flow rate about 10 litters per minute.

  11. A multiphase flow meter for the on-line determination of the flow rates of oil, water and gas

    International Nuclear Information System (INIS)

    Roach, G.J.; Watt, J.S.

    1997-01-01

    Multiphase mixtures of crude oil, formation water and gas are carried in pipelines from oil wells to production facilities. Multiphase flow meters (MFMs) are being developed to determine the flow rates of each component of the heterogeneous mixture in the pipeline. CSIRO Minerals has developed and field tested a gamma-ray MFM for the on-line determination of the flow rates of heterogeneous mixtures of oil, water and gas in pipelines. It consists of two specialised gamma-ray transmission gauges, and pressure and temperature sensors, mounted on the pipeline carrying the full flow of the production stream. The MFM separately measures liquids and gas flow rates, and the volume ratio of water and liquids (water cut). The MFM has been trialled at three offshore production facilities in Australia. In each, the MFM was mounted on the pipeline between the test manifold and the test separator. The multiphase streams from the various wells feeding to the platform were sequentially routed past the MFM. The MFM and test separator outputs were compared using regression analysis. The flow rates of oil, water and gas were each determined to relative errors in the range of 5-10% . The MFM has been in routine use on the West Kingfish platform in the Bass Strait since November 1994. The MFM was recently tested over a wide range of flow conditions at a Texaco flow facility near Houston. Water cut, based on pre-trial calibration, was determined to 2% rms over the range 0-100% water cut. The liquids and gas flow results were interpreted based on slip correlations obtained from comparison of the MFM and Texaco flows. Using these, the relative errors were respectively 6.6% for liquid flow, 6.2% for gas, 8% for oil and 8% for water. The MFM is licensed to Kvaerner FSSL of Aberdeen. Kvaerner will supply the gamma-ray MFM for both platform and subsea use. Technology transfer commenced in December 1996, and Kvaerner completed the manufacture of the first MFM in August 1997

  12. A multiphase flow meter for the on-line determination of the flow rates of oil, water and gas

    Energy Technology Data Exchange (ETDEWEB)

    Roach, G.J.; Watt, J.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Menai, NSW (Australia). Divsion of Minerals

    1997-10-01

    Multiphase mixtures of crude oil, formation water and gas are carried in pipelines from oil wells to production facilities. Multiphase flow meters (MFMs) are being developed to determine the flow rates of each component of the heterogeneous mixture in the pipeline. CSIRO Minerals has developed and field tested a gamma-ray MFM for the on-line determination of the flow rates of heterogeneous mixtures of oil, water and gas in pipelines. It consists of two specialised gamma-ray transmission gauges, and pressure and temperature sensors, mounted on the pipeline carrying the full flow of the production stream. The MFM separately measures liquids and gas flow rates, and the volume ratio of water and liquids (water cut). The MFM has been trialled at three offshore production facilities in Australia. In each, the MFM was mounted on the pipeline between the test manifold and the test separator. The multiphase streams from the various wells feeding to the platform were sequentially routed past the MFM. The MFM and test separator outputs were compared using regression analysis. The flow rates of oil, water and gas were each determined to relative errors in the range of 5-10% . The MFM has been in routine use on the West Kingfish platform in the Bass Strait since November 1994. The MFM was recently tested over a wide range of flow conditions at a Texaco flow facility near Houston. Water cut, based on pre-trial calibration, was determined to 2% rms over the range 0-100% water cut. The liquids and gas flow results were interpreted based on slip correlations obtained from comparison of the MFM and Texaco flows. Using these, the relative errors were respectively 6.6% for liquid flow, 6.2% for gas, 8% for oil and 8% for water. The MFM is licensed to Kvaerner FSSL of Aberdeen. Kvaerner will supply the gamma-ray MFM for both platform and subsea use. Technology transfer commenced in December 1996, and Kvaerner completed the manufacture of the first MFM in August 1997 4 refs., 7 figs.

  13. Pulpal blood flow recorded from exposed dentine with a laser Doppler flow meter using red or infrared light.

    Science.gov (United States)

    Kijsamanmith, Kanittha; Vongsavan, Noppakun; Matthews, Bruce

    2018-03-01

    To determine the percentage of the blood flow signal that is derived from dental pulp when recording from exposed dentine in a human premolar. Recordings were made from 7 healthy teeth in 5 subjects (aged 22-33 yr.) with a laser Doppler flow meter (Periflux 4001) using either a red (635 nm) or an infrared (780 nm) laser. After exposing dentine above the buccal pulpal horn (cavity diam. 1.6 mm, depth 3 mm) and isolating the crown with opaque rubber dam, blood flow was recorded alternately with infrared or red light from the exposed dentine under four conditions: before and after injecting local anaesthetic (3% Mepivacaine without vasoconstrictor) (LA) over the apex of the root of the tooth; after exposing the pulp by cutting a buccal, class V cavity in the tooth; and after sectioning the coronal pulp transversely through the exposure. There was no significant change in mean blood flow recorded with either light source when the tooth was anaesthetized or when the pulp was exposed. After the pulp had been sectioned, the blood flow recorded with infrared light fell by 67.8% and with red light, by 68.4%. The difference between these effects was not significant. When recording blood flow from exposed coronal dentine with either infrared or red light in a tooth isolated with opaque rubber dam, about 68% to the signal was contributed by the pulp. The signal:noise ratio was better with infrared than red light, and when recording from dentine than enamel. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Proposed method for reconstructing velocity profiles using a multi-electrode electromagnetic flow meter

    International Nuclear Information System (INIS)

    Kollár, László E; Lucas, Gary P; Zhang, Zhichao

    2014-01-01

    An analytical method is developed for the reconstruction of velocity profiles using measured potential distributions obtained around the boundary of a multi-electrode electromagnetic flow meter (EMFM). The method is based on the discrete Fourier transform (DFT), and is implemented in Matlab. The method assumes the velocity profile in a section of a pipe as a superposition of polynomials up to sixth order. Each polynomial component is defined along a specific direction in the plane of the pipe section. For a potential distribution obtained in a uniform magnetic field, this direction is not unique for quadratic and higher-order components; thus, multiple possible solutions exist for the reconstructed velocity profile. A procedure for choosing the optimum velocity profile is proposed. It is applicable for single-phase or two-phase flows, and requires measurement of the potential distribution in a non-uniform magnetic field. The potential distribution in this non-uniform magnetic field is also calculated for the possible solutions using weight values. Then, the velocity profile with the calculated potential distribution which is closest to the measured one provides the optimum solution. The reliability of the method is first demonstrated by reconstructing an artificial velocity profile defined by polynomial functions. Next, velocity profiles in different two-phase flows, based on results from the literature, are used to define the input velocity fields. In all cases, COMSOL Multiphysics is used to model the physical specifications of the EMFM and to simulate the measurements; thus, COMSOL simulations produce the potential distributions on the internal circumference of the flow pipe. These potential distributions serve as inputs for the analytical method. The reconstructed velocity profiles show satisfactory agreement with the input velocity profiles. The method described in this paper is most suitable for stratified flows and is not applicable to axisymmetric flows in

  15. Novel air flow meter for an automobile engine using a Si sensor with porous Si thermal isolation.

    Science.gov (United States)

    Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G

    2012-11-02

    An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine.

  16. 40 CFR 86.1320-90 - Gas meter or flow instrumentation calibration; particulate, methanol, and formaldehyde measurement.

    Science.gov (United States)

    2010-07-01

    ... calibration; particulate, methanol, and formaldehyde measurement. 86.1320-90 Section 86.1320-90 Protection of... instrumentation calibration; particulate, methanol, and formaldehyde measurement. (a) Sampling for particulate, methanol and formaldehyde emissions requires the use of gas meters or flow instrumentation to determine...

  17. Experimental procedure for the determination of counting efficiency and sampling flow rate of a grab-sampling working level meter

    International Nuclear Information System (INIS)

    Grenier, M.; Bigu, J.

    1982-07-01

    The calibration procedures used for a working level meter (WLM) of the grab-sampling type are presented in detail. The WLM tested is a Pylon WL-1000C working level meter and it was calibrated for radon/thoron daughter counting efficiency (E), for sampling pump flow rate (Q) and other variables of interest. For the instrument calibrated at the Elliot Lake Laboratory, E was 0.22 +- 0.01 while Q was 4.50 +- 0.01 L/min

  18. Test plan for evaluation of primary exhaust ventilation flow meters for double shell hydrogen watch list tanks

    International Nuclear Information System (INIS)

    Willingham, W.E.

    1996-01-01

    This document is a plan for testing four different flow meters for use in the primary exhaust ventilation ducts of Double Shell Tanks on the hydrogen watch list that do not already have this capability. This currently includes tanks 241-AW-101, 241-AN-103, 241-AN-104, 241-AN-105, and 241-SY-103. The anticipated airflow velocity in these tanks range from 0.25 m/s(50 ft/min) to 1.78 m/s (350 ft/min). Past experiences at Hanford are forcing the evaluation and selection of instruments to be used at the low flow and relatively high humidity conditions found in these tanks. Based on the results of this test, a flow meter shall be chosen for installation in the primary exhaust ventilation ducts of the above mentioned waste tanks

  19. An evaluation of the active fracture concept with modelingunsaturated flow and transport in a fractured meter-sized block ofrock

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Yongkoo; Kneafsey, Timothy J.; Ito, Kazumasa

    2003-05-30

    Numerical simulation is an effective and economical tool for optimally designing laboratory experiments and deriving practical experimental conditions. We executed a detailed numerical simulation study to examine the active fracture concept (AFC, Liu et al., 1998) using a cubic meter-sized block model. The numerical simulations for this study were performed by applying various experimental conditions, including different bottom flow boundaries, varying injection rates, and different fracture-matrix interaction (by increasing absolute matrix permeability at the fracture matrix boundary) for a larger fracture interaction under transient or balanced-state flow regimes. Two conceptual block models were developed based on different numerical approaches: a two-dimensional discrete-fracture-network model (DFNM) and a one-dimensional dual continuum model (DCM). The DFNM was used as a surrogate for a natural block to produce synthetic breakthrough curves of water and tracer concentration under transient or balanced-state conditions. The DCM is the approach typically used for the Yucca Mountain Project because of its computational efficiency. The AFC was incorporated into the DCM to capture heterogeneous flow patterns that occur in unsaturated fractured rocks. The simulation results from the DCM were compared with the results from the DFNM to determine whether the DCM could predict the water flow and tracer transport observed in the DFNM at the scale of the experiment. It was found that implementing the AFC in the DCM improved the prediction of unsaturated flow and that the flow and transport experiments with low injection rates in the DFNM were compared better with the AFC implemented DCM at the meter scale. However, the estimated AFC parameter varied from 0.38 to 1.0 with different flow conditions, suggesting that the AFC parameter was not a sufficient to fully capture the complexity of the flow processes in a one meter sized discrete fracture network.

  20. 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...

  1. 40 CFR 1065.240 - Dilution air and diluted exhaust flow meters.

    Science.gov (United States)

    2010-07-01

    ... straightening fins to establish a predictable velocity profile upstream of the meter. (d) Exhaust cooling. You... following provisions: (1) Do not sample PM downstream of the cooling. (2) If cooling causes exhaust temperatures above 202 °C to decrease to below 180 °C, do not sample NMHC downstream of the cooling for...

  2. Flow-Signature Analysis of Water Consumption in Nonresidential Building Water Networks Using High-Resolution and Medium-Resolution Smart Meter Data: Two Case Studies

    Science.gov (United States)

    Clifford, Eoghan; Mulligan, Sean; Comer, Joanne; Hannon, Louise

    2018-01-01

    Real-time monitoring of water consumption activities can be an effective mechanism to achieve efficient water network management. This approach, largely enabled by the advent of smart metering technologies, is gradually being practiced in domestic and industrial contexts. In particular, identifying water consumption habits from flow-signatures, i.e., the specific end-usage patterns, is being investigated as a means for conservation in both the residential and nonresidential context. However, the quality of meter data is bivariate (dependent on number of meters and data temporal resolution) and as a result, planning a smart metering scheme is relatively difficult with no generic design approach available. In this study, a comprehensive medium-resolution to high-resolution smart metering program was implemented at two nonresidential trial sites to evaluate the effect of spatial and temporal data aggregation. It was found that medium-resolution water meter data were capable of exposing regular, continuous, peak use, and diurnal patterns which reflect group wide end-usage characteristics. The high-resolution meter data permitted flow-signature at a personal end-use level. Through this unique opportunity to observe water usage characteristics via flow-signature patterns, newly defined hydraulic-based design coefficients determined from Poisson rectangular pulse were developed to intuitively aid in the process of pattern discovery with implications for automated activity recognition applications. A smart meter classification and siting index was introduced which categorizes meter resolution in terms of their suitable application.

  3. Design and construction of a novel Coriolis mass flow rate meter

    NARCIS (Netherlands)

    Mehendale, A.; Zwikker, Rini; Jouwsma, Wybren

    2009-01-01

    The Coriolis principle for measuring flow rates has great advantages compared to other flow measurement principles, the most important being that mass flow is measured directly. Up to now the measurement of low flow rates posed a great challenge. In a joint research project, the University of Twente

  4. Fabrication and evaluation of a graphene oxide-based cantilever-type flow-meter for subsonic gas flow rate measurement

    Science.gov (United States)

    Hamdollahi, Hassan; Rahbar-Shahrouzi, Javad

    2018-05-01

    In this paper, a cantilever-type flow meter was fabricated to measure the rate of air flow in turbulent subsonic regimes such as purged gases. In the fabrication process, a piezoresistive material was coated on an interdigitated electric board as a substrate. The piezoresistive layer was a blend of latex as the polymeric matrix and graphene oxide as the sensing nanomaterial agent, which was reduced by solvothermal reduction method. The piezoresistive blend was dip-coated on a substrate with dotted pattern and was then reduced at 240 °C for 1 h in every coating step. When an air flow passed over the surface of the cantilever beam, the beam was bent in the downward direction, resulting in small variations in the resistance of the piezoresistive layer and a change in the bending angle of the cantilever which were measured simultaneously. The air flow rate was acquired via calibrating electrical resistance changes by Arduino and Wheatstone bridge circuit. The blending angle of the substrate caused by the interaction between the airflow and the cantilever and recorded by the camera and image processing was ultimately compared with the simulation results. The flow meter accuracy as a percentage of full scale (% FS) was calculated to be  ±5.8%, and mean deviation was equal to 2.1 (% FS) with the appropriate response time of 0.70 s at the air flow range of 100‑240 m s‑1. Highlights • A cantilever-type flow meter was fabricated to measure the high-speed air flow rate. • The sensitive piezoresistive material was composed of GO and latex. • The dip-coating method was used to deposit the piezoresistive layer on the fiberglass substrate. • The impact of effective parameters on the performance of the flow meter was investigated. • A simulation study was performed and the results were compared with the experimental data.

  5. The wire-mesh sensor as a two-phase flow meter

    International Nuclear Information System (INIS)

    Shaban, H; Tavoularis, S

    2015-01-01

    A novel gas and liquid flow rate measurement method is proposed for use in vertical upward and downward gas–liquid pipe flows. This method is based on the analysis of the time history of area-averaged void fraction that is measured using a conductivity wire-mesh sensor (WMS). WMS measurements were collected in vertical upward and downward air–water flows in a pipe with an internal diameter of 32.5 mm at nearly atmospheric pressure. The relative frequencies and the power spectral density of area-averaged void fraction were calculated and used as representative properties. Independent features, extracted from these properties using Principal Component Analysis and Independent Component Analysis, were used as inputs to artificial neural networks, which were trained to give the gas and liquid flow rates as outputs. The present method was shown to be accurate for all four encountered flow regimes and for a wide range of flow conditions. Besides providing accurate predictions for steady flows, the method was also tested successfully in three flows with transient liquid flow rates. The method was augmented by the use of the cross-correlation function of area-averaged void fraction determined from the output of a dual WMS unit as an additional representative property, which was found to improve the accuracy of flow rate prediction. (paper)

  6. Techniques for measuring renal transit time

    Energy Technology Data Exchange (ETDEWEB)

    Russell, C.D. [Div. of Nuclear Medicine, Univ. of Alabama at Birmingham Medical Center, AL (United States)]|[Nuclear Medicine Service, V.A. Medical Center, Birmingham, AL (United States); Japanwalla, M. [Div. of Nuclear Medicine, Univ. of Alabama at Birmingham Medical Center, AL (United States)]|[Nuclear Medicine Service, V.A. Medical Center, Birmingham, AL (United States); Khan, S. [Div. of Nuclear Medicine, Univ. of Alabama at Birmingham Medical Center, AL (United States)]|[Nuclear Medicine Service, V.A. Medical Center, Birmingham, AL (United States); Scott, J.W. [Div. of Nuclear Medicine, Univ. of Alabama at Birmingham Medical Center, AL (United States)]|[Nuclear Medicine Service, V.A. Medical Center, Birmingham, AL (United States); Dubovsky, E.V. [Div. of Nuclear Medicine, Univ. of Alabama at Birmingham Medical Center, AL (United States)]|[Nuclear Medicine Service, V.A. Medical Center, Birmingham, AL (United States)

    1995-12-01

    A variety of techniques have been used for quantitative estimation of renal transit time. We compared different indices of transit time in a group of 30 patients having baseline and ACE inhibitor technetium-99m mercaptoacetyltriglycine (MAG{sub 3}) renography prior to arteriography: Peak time, mean transit time, and the ratio of background-subtracted counts at 20 min to those at 3 min. Each index was calculated from whole-kidney ROI, cortical ROI, and cortical factor (by factor analysis). The strongest correlations between angiographic percent of stenosis and transit time index were observed for the peak time (Spearman {rho}=0.469, n=53) and for the R20/3 (again {rho}=0.469, n=53) using the whole-kidney ROI and using only the baseline data without captopril. (Spearman`s {rho} is simply the correlation coefficient calculated from rank in list, which allows for nonlinear correlation.) Thus simple indices of transit time (whole-kidney peak time and R20/3) correlated as well with the observed pathology as did more complicated methods that required deconvolution, factor analysis, or selection of a cortical ROI. (orig./MG)

  7. Meter-Scale Reactive Transport Modeling of CO2-Rich Fluid Flow along Debonded Wellbore Casing-Cement Interfaces.

    Science.gov (United States)

    Wolterbeek, Timotheus K T; Raoof, Amir

    2018-03-20

    Defects along wellbore interfaces constitute potential pathways for CO 2 to leak from geological storage systems. In previous experimental work, we demonstrated that CO 2 -induced reaction over length-scales of several meters can lead to self-sealing of such defects. In the present work, we develop a reactive transport model that, on the one hand, enables μm-mm scale exploration of reactions along debonding defects and, on the other hand, allows simulation of the large, 6 m-long samples used in our experiments. At these lengths, we find that interplay between flow velocity and reaction rate strongly affects opening/sealing of interfacial defects, and depth of chemical alteration. Carbonate precipitation in initially open defects decreases flow rate, leading to a transition from advection-dominated to diffusion-dominated reactive transport, with acidic conditions becoming progressively more confined upstream. We investigate how reaction kinetics, portlandite content, and the nature of the carbonate products impact the extent of cement alteration and permeability reduction. Notably, we observe that nonuniformity of the initial defect geometry has a profound effect on the self-sealing behavior and permeability evolution as observed on the meter scale. We infer that future wellbore models need to consider the effects of such aperture variations to obtain reliable upscaling relations.

  8. Fabrication of a cantilever-based microfluidic flow meter with nL min(-1) resolution

    DEFF Research Database (Denmark)

    Noeth, Nadine-Nicole; Keller, Stephan Sylvest; Boisen, Anja

    2011-01-01

    ). With this etch the cantilever structures are under-etched before they are released by tweezers and the release yield is enhanced from 41.5% to 84.0%. In a continuous flow mode, the deflection of the cantilevers is directly proportional to the flow rate. By tuning the design of the integrated grid (hole size...

  9. A Matheuristic for the Liner Shipping Network Design Problem with Transit Time Restrictions

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Desaulniers, Guy; Karsten, Christian Vad

    2015-01-01

    We present a mathematical model for the liner shipping network design problem with transit time restrictions on the cargo flow. We extend an existing matheuristic for the liner shipping network design problem to consider transit time restrictions. The matheuristic is an improvement heuristic, where...

  10. Lateral flow assay with pressure meter readout for rapid point-of-care detection of disease-associated protein.

    Science.gov (United States)

    Lin, Bingqian; Guan, Zhichao; Song, Yanling; Song, Eunyeong; Lu, Zifei; Liu, Dan; An, Yuan; Zhu, Zhi; Zhou, Leiji; Yang, Chaoyong

    2018-02-26

    Paper-based assays such as lateral flow assays are good candidates for portable diagnostics owing to their user-friendly format and low cost. In terms of analytical detection, lateral flow assays usually require dedicated instruments to obtain quantitative results. Here we demonstrate a lateral flow assay with handheld pressure meter readout for the rapid detection of disease-related protein with high sensitivity and selectivity. Based on the pressure change produced by the catalytic reaction of Pt nanoparticles related to the concentration of the target, a quantitative reaction platform was established. During the lateral flow assay, the Pt nanoparticles are aggregated in the test line to form a gray band by biomolecular recognition and finally convert the recognition signal into highly sensitive pressure readout for quantitative analysis. Without sophisticated instrumentation and complicated operations, the whole detection process can be completed within 20 minutes. The limit of detection for myoglobin (2.9 ng mL -1 in diluted serum samples) meets the requirements of clinical monitoring. With the advantages of low cost, ease of operation, high sensitivity and selectivity, the method represents a versatile platform for point-of-care testing of disease biomarkers.

  11. Multi Parameter Flow Meter for On-Line Measurement of Gas Mixture Composition

    Directory of Open Access Journals (Sweden)

    Egbert van der Wouden

    2015-04-01

    Full Text Available In this paper we describe the development of a system and model to analyze the composition of gas mixtures up to four components. The system consists of a Coriolis mass flow sensor, density, pressure and thermal flow sensor. With this system it is possible to measure the viscosity, density, heat capacity and flow rate of the medium. In a next step the composition can be analyzed if the constituents of the mixture are known. This makes the approach universally applicable to all gasses as long as the number of components does not exceed the number of measured properties and as long as the properties are measured with a sufficient accuracy. We present measurements with binary and ternary gas mixtures, on compositions that range over an order of magnitude in value for the physical properties. Two platforms for analyses are presented. The first platform consists of sensors realized with MEMS fabrication technology. This approach allows for a system with a high level of integration. With this system we demonstrate a proof of principle for the analyses of binary mixtures with an accuracy of 10%. In the second platform we utilize more mature steel sensor technology to demonstrate the potential of this approach. We show that with this technique, binary mixtures can be measured within 1% and ternary gas mixtures within 3%.

  12. Transit time for third order resonance extraction

    CERN Document Server

    Pullia, M

    1996-01-01

    An important spin-off from accelerators is the use of synchrotrons for cancer therapy. A precise control of the extraction from the synchrotron is needed to satisfy the medical specifications and this has led to a renewed interest in the basic theory of third-order resonance extraction. In the present paper, a complete description of the transit time in the resonance (the time between a particle becoming unstable and reaching the electrostatic septum) is developed as a basis for future work predicting spill shapes and the influence of power supply ripple. The transit time is evaluated for constant tune and for a slowly varying tune. Both cases are subdivided into particles that start close simulation and are shown to be correct to within a few percent.

  13. 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.

  14. Robust, non-invasive methods for metering groundwater well extraction in remote environments

    Science.gov (United States)

    Bulovic, Nevenka; Keir, Greg; McIntyre, Neil

    2017-04-01

    Quantifying the rate of extraction from groundwater wells can be essential for regional scale groundwater management and impact assessment. This is especially the case in regions heavily dependent on groundwater such as the semi-arid Surat and Bowen Basins in Queensland, Australia. Of the 30 000+ groundwater wells in this area, the majority of which are used for stock watering and domestic purposes, almost none have flow metering devices installed. As part of a research project to estimate regional groundwater extraction, we have undertaken a small scale flow metering program on a selected set of wells. Conventional in-line flow meters were unsuitable for our project, as both non-invasiveness and adaptability / suitability to a variety of discharge pipe characteristics was critical. We describe the use of two metering technologies not widely used in groundwater applications, non-invasive, clamp-on ultrasonic transit time flow meters and tipping bucket flow meters, as semi-permanent installations on discharge pipes of various artesian and sub-artesian groundwater wells. We present examples of detailed extraction rate time-series, which are of particular value in developing predictive models of water well extraction in data limited areas where water use dynamics and drivers are poorly understood. We conclude by discussing future project trajectories, which include expansion of the monitoring network through development of novel metering techniques and telemetry across large areas of poor connectivity.

  15. Radioisotope conveyor ash meter

    International Nuclear Information System (INIS)

    Savelov, V.D.

    1994-01-01

    Radioisotope conveyor ash meter realizes persistent measuring of ashiness of coal and products of its enrichment on the belt conveyor without contact. The principle of ash meter acting is based on functional dependence of the gamma radiation flows backscattering intensity of radioisotope sources from the ash volume content in the controlled fuel. Facility consists from the ashiness transducer and the processing and control device

  16. A comparison of peak expiratory flow measured from forced vital capacity and peak flow meter manoeuvres in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Agarwal Dipti

    2007-01-01

    Full Text Available Background: Spirometry measures the mechanical function of lungs, chest wall and respiratory muscles by assessing the total volume of air exhaled from total lung capacity to residual volume. Spirometry and peak flow measurements have usually been carried out on separate equipments using different expiratory maneuvers. Aims: The present study was carried out to determine whether there is a significant difference between peak expiratory flow (PEF derived from a short sharp exhalation (PEF maneuver and that derived from a full forced vital capacity (FVC maneuver in healthy volunteers. Settings: A medical college and tertiary level hospital. Materials and Methods: The present study was carried out during the period from January 2006 to July 2006. The study included 80 healthy volunteers with no coexisting illnesses, who were in the 15-45 years age group and belonging to either sex. They were asked to perform two sets of PEF and FVC maneuvers using the same turbine spirometer; the order was randomly assigned.th Statistical Analysis: The difference between PEF obtained from a peak flow maneuver (PEFPF and that obtained from a forced vital capacity maneuver (PEFVC in healthy volunteers was analyzed separately for males and females, as well as for both groups combined, and statistical significance of its correlations with study data parameters was analyzed.th Results: The difference between PEF obtained from a peak flow maneuver (PEFPF and that obtained from a forced vital capacity maneuver (PEFVC was statistically significant ( P < 0.001 in males and in females separately and also for both groups combined. PEFPF (517.25 ± 83.22 liters/min was significantly greater than PEFVC (511.09 ± 83.54 liters/min, as found on combined group mean analysis. However, the difference was small (6.16 + 7.09 liters/min. Conclusions: FVC maneuver can be used over spirometers to detect the PEF; and on follow-up subsequently, the same maneuver should be used to derive PEF

  17. Proof-of-principle demonstration of a virtual flow meter-based transducer for gaseous helium monitoring in particle accelerator cryogenics

    Science.gov (United States)

    Arpaia, P.; Blanco, E.; Girone, M.; Inglese, V.; Pezzetti, M.; Piccinelli, F.; Serio, L.

    2015-07-01

    A transducer based on a virtual flow meter is proposed for monitoring helium distribution and consumption in cryogenic systems for particle accelerators. The virtual flow meter allows technical and economical constraints, preventing installation of physical instruments in all the needed measurement points, to be overcome. Virtual flow meter performance for the alternative models of Samson [http://www.samson.de (2015)] and Sereg-Schlumberger [http://www.slb.com/ (2015)] is compared with the standard IEC 60534-2-1 [Industrial-process control valves—Part 2-1: Flow capacity—sizing equations for fluid flow under installed conditions (2011), https://webstore.iec.ch/publication/2461], for a large temperature range, for both gaseous and liquid helium phases, and for different pressure drops. Then, the calibration function of the transducer is derived. Finally, the experimental validation for the helium gaseous state on the test station for superconducting magnets in the laboratory SM18 [Pirotte et al., AIP Conf. Proc. 1573, 187 (2014)] at CERN is reported.

  18. 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

  19. 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

  20. Advances in gas flow metering - end of the history, peaceful co-existence or a new beginning; Les avancees dans le mesurage des debits de gaz - fin de l'histoire, coexistence pacifique ou nouveau commencement

    Energy Technology Data Exchange (ETDEWEB)

    Studzinski, W. [NOVA Research and Technology Centre, Calgary (Canada)

    2000-07-01

    Gas flow metering plays an important role in the technical and fiscal operations of pipeline systems. Over the last hundred years, the industry has gone through several technical revolutions. The recent two decades were characterized by the introduction of flow computers in the 80's and acceptance of ultrasonic meters in the 90's. These changes, associated with measurement technology, have had a profound impact on pipeline operation, deregulation of the gas industry and gas trading. Significant advances were made, however, it is certainly not the end for progress in gas flow metering. The future development of optoelectronic and mass flow meters combined with advances in telemetry and tele-calibration may significantly reduce capital and maintenance costs. Classical flow meters will be upgraded to a new level of performance and will co-exist with the newest technologies. The uncertainty of flow measurement will be improved, mainly in terms of stability over longer periods of time. Old and new meters will be able to perform in environments other than dry natural gas. Processing of flow measurement data will evolve with the progress in flow computers and smart transmitters. The advances in gas flow metering will be driven by life cycle cost reduction as well as new business and service requirements. (author)

  1. Assessing the controls and uncertainties on mean transit times in contrasting headwater catchments

    Science.gov (United States)

    Cartwright, Ian; Irvine, Dylan; Burton, Chad; Morgenstern, Uwe

    2018-02-01

    Estimating the time required for water to travel through headwater catchments from where it recharges to where it discharges into streams (the transit time) is important for understanding catchment behaviour. This study uses tritium (3H) activities of stream water to estimate the mean transit times of water in the upper Latrobe and Yarra catchments, southeast Australia, at different flow conditions. The 3H activities of the stream water were between 1.26 and 1.99 TU, which are lower than those of local rainfall (2.6 to 3.0 TU). 3H activities in individual subcatchments are almost invariably lowest at low streamflows. Mean transit times calculated from the 3H activities using a range of lumped parameter models are between 7 and 62 years and are longest during low streamflows. Uncertainties in the estimated mean transit times result from uncertainties in the geometry of the flow systems, uncertainties in the 3H input, and macroscopic mixing. In addition, simulation of 3H activities in FEFLOW indicates that heterogeneous hydraulic conductivities increase the range of mean transit times corresponding to a specific 3H activity. The absolute uncertainties in the mean transit times may be up to ±30 years. However, differences between mean transit times at different streamflows in the same catchment or between different subcatchments in the same area are more reliably estimated. Despite the uncertainties, the conclusions that the mean transit times are years to decades and decrease with increasing streamflow are robust. The seasonal variation in major ion geochemistry and 3H activities indicate that the higher general streamflows in winter are sustained by water displaced from shallower younger stores (e.g., soils or regolith). Poor correlations between 3H activities and catchment area, drainage density, mean slope, distance to stream, and landuse, imply that mean transit times are controlled by a variety of factors including the hydraulic properties of the soils and

  2. Current meter data from moored current meter casts in the Northeast Pacific Ocean as part of the Flow Over Abrupt Topography project from 1990-01-06 to 1991-12-03 (NODC Accession 9500077)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Northeast Pacific Ocean from January 6, 1990 to December 3, 1991. Data were submitted by...

  3. 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.

  4. 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.

  5. 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...... find that the occurrence rate of planet candidates that show TTVs is significantly increased (~68%) for planet candidates transiting stars with multiple transiting planet candidates when compared to planet candidates transiting stars with a single transiting planet candidate....

  6. Study of a three-phase flow metering process for oil-water-gas flows; Etude d`un procede de mesure des debits d`un ecoulement triphasique de type eau-huile-gaz

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Ch.

    1996-11-01

    We propose a theoretical and experimental study of a three-phase flow metering process for oil-water-gas flows. The selected process is based on a combination of a mixer, a Venturi and ultrasonic methods. To perform an experimental validation of this process an instrumented set-up for three-phase air-oil-water flows has been designed, conceived and adjusted. An original theoretical model have been built to predict three-phase dispersed flows across a contraction. Once validated with two-phase air-water, oil-water and air-oil-water flows data, this model has been used to solve the Venturi metering problems. After a critical review of the available techniques, the ultrasonic propagation velocity has been selected to determine two-phase liquid-liquid flow composition. Two original models have been developed to describe the ultrasonic propagation with the dispersed phase fraction. The comparison with experimental data in oil-water flows show the superiority of one of the two models, the scattering model. For the void fraction determination in air-water flows, the work of Bensler (1990) based on the ultrasonic attenuation measurement has been extended to take into account the multiple scattering effects. Finally these techniques have been combined to determine the different flow rates in air-water, oil-water flows. For two-phase air-water and oil-water flows the problem is solved and the flow rates are measured with a very good accuracy ({+-} 3%). The results quality obtained with three-phase oil-water-gas flows and the secure theoretical bases allowing their interpretation give us the opportunity to strongly recommend the development of an industrial prototype based on the process we studied. (author) 183 refs.

  7. Using a physically-based transit time distribution function to estimate the hydraulic parameters and hydraulic transit times of an unconfined aquifer from tritium measurements

    Science.gov (United States)

    Farlin, Julien; Maloszewski, Piotr; Schneider, Wilfried; Gallé, Tom

    2014-05-01

    Groundwater transit time is of interest in environmental studies pertaining to the transport of pollutants from its source to the aquifer outlet (spring or pumping well) or to an observation well. Different models have been proposed to describe the distribution of transit times within groundwatersheds, the most common being the dispersion model, the exponential-piston-flow model (EPM) both proposed by Maloszewski and Zuber (Maloszewski and Zuber, 1982) and the (two or three parameter) gamma model (Amin and Campana, 1996; Kirchner et al., 1999). Choosing which function applies best is a recurrent and controversial problem in hydrogeology. The object of this study is to revisit the applicability of the EPM for unconfined aquifers, and to introduce an alternative model based explicitly on groundwater hydraulics. The alternative model is based on the transit time of water from any point at the groundwater table to the aquifer outlet, and is used to calculate inversely the hydraulic parameters of a fractured unconfined sandstone aquifer from tritium measurements made in a series of contact springs. This model is compared to the EPM, which is usually adopted to describe the transit time distribution of confined and unconfined aquifers alike. Both models are tested against observations, and it is shown that the EPM fails the test for some of the springs, and generally seems to overestimate the older water component. Amin, I. E., and M. E. Campana (1996), A general lumped parameter model for the interpretation of tracer data and transit time calculation in hydrologic systems, Journal of Hydrology, 179, 1-21, doi: 10.1016/0022-1694(95)02880-3. Kirchner, J. W., X. H. Feng, and C. Neal (1999), Fractal stream chemistry and its implications for contaminant transport in catchments, Nature physics, 403, 524-527, doi: 10.1038/35000537. Maloszewski, P., and A. Zuber (1982), Determining the turnover time of groundwater systems with the aid of environmental tracers, Journal of

  8. Twin Cities ramp meter evaluation : executive summary

    Science.gov (United States)

    2001-02-01

    This report details the results of a study on the traffic flow and safety impacts of ramp metering. The study served two important public purposes. 1. It thoroughly documented the benefits resulting from ramp metering to traffic operations and relate...

  9. 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.

  10. Gastrointestinal transit times and motility in patients with cystic fibrosis

    DEFF Research Database (Denmark)

    Hedsund, Caroline; Gregersen, Tine; Jønsson, Iben

    2012-01-01

    OBJECTIVE: Patients with cystic fibrosis (CF) often suffer from gastrointestinal (GI) dysfunction including obstructive symptoms, malabsorption and pain, but the underlying pathophysiology remains obscure. AIM: To compare GI motility and transit times in CF patients and healthy controls. MATERIAL...

  11. Experimental study of an electromagnetic flow meter for liquid metals based on torque measurement during pumping process

    International Nuclear Information System (INIS)

    Dubovikova, N; Kolesnikov, Y; Karcher, Ch

    2015-01-01

    This paper presents a detailed experimental study on an electromagnetic flow measurement technique to measure the flow rate of liquid metals. The experimental setup consists of a contactless electromagnetic pump with a torque sensor mounted on the pump shaft. The electromagnetic pump is composed of two rotating steel discs having embedded permanent magnets with alternating poles. The rotation of the discs creates a travelling sinusoidal magnetic field and eddy currents within the liquid metal. The metal is contained inside the duct located between the discs of the pump. The interaction of the magnetic field and the induced eddy currents generates an electromagnetic Lorentz force providing the pumping effect. The flow rate is proportional to this force. The torque sensor measures the moment of the discs due to the Lorentz force, which is converted to a flow rate value. We name the method Lorentz torque velocimetry (LTV). The full calibration procedure and experimental investigation of the LTV are described. The method can be used as a non-contact flow rate control technique for liquid metals. (paper)

  12. Ultrasonic meters in the feedwater flow to recover thermal power in the reactor of nuclear power plant of Laguna Verde U1 and U2

    International Nuclear Information System (INIS)

    Tijerina S, F.

    2008-01-01

    The engineers in nuclear power plants BWRs and PWRs based on the development of the ultrasonic technology for the measurement of the mass, volumetric flow, density and temperature in fluids, have applied this technology in two primary targets approved by the NRC: the use for the recovery of thermal power in the reactor and/or to be able to realize an increase of thermal power licensed in a 2% (MUR) by 1OCFR50 Appendix K. The present article mentions the current problem in the measurement of the feedwater flow with Venturi meters, which affects that the thermal balance of reactor BWRs or PWRs this underestimated. One in broad strokes describes the application of the ultrasonic technology for the ultrasonic measurement in the flow of the feedwater system of the reactor and power to recover thermal power of the reactor. One is to the methodology developed in CFE for a calibration of the temperature transmitters of RTD's and the methodology for a calibration of the venturi flow transmitters using ultrasonic measurement. Are show the measurements in the feedwater of reactor of the temperature with RTD's and ultrasonic measurement, as well as the flow with the venturi and the ultrasonic measurement operating the reactor to the 100% of nominal thermal power, before and after the calibration of the temperature transmitters and flow. Finally, is a plan to be able to realize a recovery of thermal power of the reactor, showing as carrying out their estimations. As a result of the application of ultrasonic technology in the feedwater of reactor BWR-5 in Laguna Verde, in the Unit 1 cycle 13 it was recover an equivalent energy to a thermal power of 25 MWt in the reactor and an exit electrical power of 6 M We in the turbogenerator. Also in the Unit 2 cycle 10 it was recover an equivalent energy to a thermal power of 40 MWt in the reactor and an exit electrical power of 16 M We in the turbogenerator. (Author)

  13. 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.

  14. Transit time for water distribution in the northern part of the Muda irrigation scheme

    International Nuclear Information System (INIS)

    Md Shahid Ayub; Kamarudin Samuding; Kamisah Alias

    2002-01-01

    This study was carried out to establish the transit times for high and low flow from the Pedu Dam through the northern part of the Muda irrigation Scheme. The result of the study would assist in the management of water released from the Pedu Dam into the irrigation system thus sustaining the rice production in the area. Peak to peak method was employed and I was used as a tracer. At high discharge, it took 3.3 days for the water from the Pedu Dam to reach the end of the system, whereas at low discharge it took 7.5 days. The transit time at high discharge seems to be more linear with distance as compared to the low discharge. For low discharge, the linearity was observed to hold only from Pedu to Kampong Kubu, after which the gradient of transit time against distance curve increased with increase of distance along the North Canal, and then decreased along the Arau Canal. For high discharge, the transit time gradient could be divided into three portions, but the differences were not significant. (Author)

  15. 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...... 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, Ptransit time and fractional colonic filling at 4 h (111In: r=-0.97, Ptransit time and geometric centre of colonic content...

  16. 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

  17. Electrical capacitance tomography (ECT) and gamma radiation meter for comparison with and validation and tuning of computational fluid dynamics (CFD) modeling of multiphase flow

    International Nuclear Information System (INIS)

    Pradeep, Chaminda; Yan, Ru; Mylvaganam, Saba; Vestøl, Sondre; Melaaen, Morten C

    2014-01-01

    The electrical capacitance tomographic (ECT) approach is increasingly seen as attractive for measurement and control applications in the process industries. Recently, there is increased interest in using the tomographic details from ECT for comparing with and validating and tuning CFD models of multiphase flow. Collaboration with researchers working in the field of computational fluid dynamics (CFD) modeling of multiphase flows gives valuable information for both groups of researchers in the field of ECT and CFD. By studying the ECT tomograms of multiphase flows under carefully monitored inflow conditions of the different media and by obtaining the capacitance values, C(i, j, t) with i = 1…N, j = 1, 2,…N and i ≠ j obtained from ECT modules with N electrodes, it is shown how the interface heights in a pipe with stratified flow of oil and air can be fruitfully compared to the values of those obtained from ECT and gamma radiation meter (GRM) for improving CFD modeling. Monitored inflow conditions in this study are flow rates of air, water and oil into a pipe which can be positioned at varying inclinations to the horizontal, thus emulating the pipelines laid in subsea installations. It is found that ECT-based tomograms show most of the features seen in the GRM-based visualizations with nearly one-to-one correspondence to interface heights obtained from these two methods, albeit some anomalies at the pipe wall. However, there are some interesting features the ECT manages to capture: features which the GRM or the CFD modeling apparently do not show, possibly due to parameters not defined in the inputs to the CFD model or much slower response of the GRM. Results presented in this paper indicate that a combination of ECT and GRM and preferably with other modalities with enhanced data fusion and analysis combined with CFD modeling can help to improve the modeling, measurement and control of multiphase flow in the oil and gas industries and in the process industries

  18. Electrical capacitance tomography (ECT) and gamma radiation meter for comparison with and validation and tuning of computational fluid dynamics (CFD) modeling of multiphase flow

    Science.gov (United States)

    Pradeep, Chaminda; Yan, Ru; Vestøl, Sondre; Melaaen, Morten C.; Mylvaganam, Saba

    2014-07-01

    The electrical capacitance tomographic (ECT) approach is increasingly seen as attractive for measurement and control applications in the process industries. Recently, there is increased interest in using the tomographic details from ECT for comparing with and validating and tuning CFD models of multiphase flow. Collaboration with researchers working in the field of computational fluid dynamics (CFD) modeling of multiphase flows gives valuable information for both groups of researchers in the field of ECT and CFD. By studying the ECT tomograms of multiphase flows under carefully monitored inflow conditions of the different media and by obtaining the capacitance values, C(i, j, t) with i = 1…N, j = 1, 2,…N and i ≠ j obtained from ECT modules with N electrodes, it is shown how the interface heights in a pipe with stratified flow of oil and air can be fruitfully compared to the values of those obtained from ECT and gamma radiation meter (GRM) for improving CFD modeling. Monitored inflow conditions in this study are flow rates of air, water and oil into a pipe which can be positioned at varying inclinations to the horizontal, thus emulating the pipelines laid in subsea installations. It is found that ECT-based tomograms show most of the features seen in the GRM-based visualizations with nearly one-to-one correspondence to interface heights obtained from these two methods, albeit some anomalies at the pipe wall. However, there are some interesting features the ECT manages to capture: features which the GRM or the CFD modeling apparently do not show, possibly due to parameters not defined in the inputs to the CFD model or much slower response of the GRM. Results presented in this paper indicate that a combination of ECT and GRM and preferably with other modalities with enhanced data fusion and analysis combined with CFD modeling can help to improve the modeling, measurement and control of multiphase flow in the oil and gas industries and in the process industries

  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. 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

  1. 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.

  2. Hot-wire air flow meter for gasoline fuel-injection system. Calculation of air mass in cylinder during transient condition; Gasoline funsha system yo no netsusenshiki kuki ryuryokei. Kato untenji no cylinder juten kukiryo no keisan

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Y. [Hitachi Car Engineering, Ltd., Tokyo (Japan); Nishimura, Y.; Osuga, M.; Yamauchi, T. [Hitachi, Ltd., Tokyo (Japan)

    1997-10-01

    Air flow characteristics of hot-wire air flow meters for gasoline fuel-injection systems with supercharging and exhaust gas recycle during transient conditions were investigated to analyze a simple method for calculating air mass in cylinder. It was clarified that the air mass in cylinder could be calculated by compensating for the change of air mass in intake system by using aerodynamic models of intake system. 3 refs., 6 figs., 1 tab.

  3. 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

  4. Real-time isotope monitoring network at the Biosphere 2 Landscape Evolution Observatory resolves meter-to-catchment scale flow dynamics

    Science.gov (United States)

    Volkmann, T. H. M.; Van Haren, J. L. M.; Kim, M.; Harman, C. J.; Pangle, L.; Meredith, L. K.; Troch, P. A.

    2017-12-01

    Stable isotope analysis is a powerful tool for tracking flow pathways, residence times, and the partitioning of water resources through catchments. However, the capacity of stable isotopes to characterize catchment hydrological dynamics has not been fully exploited as commonly used methodologies constrain the frequency and extent at which isotopic data is available across hydrologically-relevant compartments (e.g. soil, plants, atmosphere, streams). Here, building upon significant recent developments in laser spectroscopy and sampling techniques, we present a fully automated monitoring network for tracing water isotopes through the three model catchments of the Landscape Evolution Observatory (LEO) at the Biosphere 2, University of Arizona. The network implements state-of-the-art techniques for monitoring in great spatiotemporal detail the stable isotope composition of water in the subsurface soil, the discharge outflow, and the atmosphere above the bare soil surface of each of the 330-m2 catchments. The extensive valving and probing systems facilitate repeated isotope measurements from a total of more than five-hundred locations across the LEO domain, complementing an already dense array of hydrometric and other sensors installed on, within, and above each catchment. The isotope monitoring network is operational and was leveraged during several months of experimentation with deuterium-labelled rain pulse applications. Data obtained during the experiments demonstrate the capacity of the monitoring network to resolve sub-meter to whole-catchment scale flow and transport dynamics in continuous time. Over the years to come, the isotope monitoring network is expected to serve as an essential tool for collaborative interdisciplinary Earth science at LEO, allowing us to disentangle changes in hydrological behavior as the model catchments evolve in time through weathering and colonization by plant communities.

  5. 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

  6. 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.)

  7. 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.

  8. Physiological variation of normal transit time in children

    International Nuclear Information System (INIS)

    Vivian, G.; Iodd-Pokropek, A.; Gordon, I.; Hospital for Sick Children, London

    1985-01-01

    Quantitation of the sup(99m)Tc-diethylenetriaminepentaacetic Acid (DTPA) scan yields by uptake analysis an estimate of individual kidney glomerular filtration rate (IKGFR) and by deconvolutional analysis an estimate of the mean transit time (MTT) of the non-reabsorbable tracer through the kidney. The whole kidney MTT is compounded of the renal parenchymal MTT and the rate of pelvic clearance; both functions are influenced by prevailing rates of salt and water excretion. The present study was undertaken to investigate the effect of physiological variations on the normal DTPA scan. The contralateral normal kidney in 11 children with suspected unilateral urinary tract obstruction were studied twice, first with an early morning scan (EMS) and second, 24 h later, following hypotonic volume expansion (HVE). A strong correlation was shown between urine osmolality and MTT. IKGFR was independent of the state of hydration, but in comparison to mild hydration, HVE shortened significantly (P<0.001) the normal whole kidney MTT, with less effect on parenchymal MTT (P<0.01) and therefore has its predominant effect on pelvic clearance. We advise caution in the interpretation of whole kidney transit time analysis without standardization of salt and water excretion rates. Parenchymal transit time offers a potentially useful clinical index. (orig.)

  9. 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.

  10. 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

  11. Metrological control of instruments, equipment and measurement system for ultrasonic meters of flow; Controle metrologico de instrumentos, equipamentos e sistema de medicao para medidores ultra-sonicos de vazao

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, Oscar de

    2004-07-01

    Following the actual tendency to obtaining greater precision in Natural Gas measurement, in the past few years the use of Ultrasonic Flow Meters as Custody Transfer applications has grown significantly. There are several units currently operating in Brazil. The legislation for model approval, measure system certification and periodical metrological control of the above mentioned equipment, is currently under elaboration final stage. It was placed under public inquire through the 'Portaria 037' of 2004 of INMETRO, which proposes the authorization to perform the Metrological control by the Operator, once it has a quality system implemented according NBR ISO 9001-2000 and/or ISO 17025. This paper describes the verification procedure adopted by most of ultrasonic meters manufacturers. It also describes the application of the procedure for create the 'Metrological Control System of the Measurement System' of a 12'' Ultrasonic Meter installed and operating, with 3 years operation's data. (author)

  12. Intracranial contrast transit times on digital subtraction angiography decrease more in patients with delayed intraparenchymal hemorrhage after Pipeline.

    Science.gov (United States)

    Brunozzi, Denise; Shakur, Sophia F; Charbel, Fady T; Alaraj, Ali

    2018-04-01

    Background Pipeline embolization devices (PEDs) are used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage (DIPH). Changes in intracranial hemodynamics after PED are poorly understood. Objective Here, we assess hemodynamic changes after PED in patients and compare these changes in patients with and without DIPH (DIPH+ and DIPH-). Methods Records of patients with distal internal carotid artery (ICA) aneurysms treated with PED at our institution between 2012 and 2017 were retrospectively reviewed. Regions of interest were selected proximally to PED over the cavernous ICA and distally over the middle cerebral artery (MCA), and then transit times were determined using syngo iFlow software (Siemens). Ratio of MCA to ICA transit time was compared before, after treatment, and at follow-up. Ratios were also compared between DIPH+ and DIPH- subgroups. Correlations between aneurysm size, age, and ratios were investigated. Results Fifty-three patients were included. The ratio of MCA to ICA transit time decreased significantly after PED deployment (1.13 vs. 1.22, p transit time decreases following PED treatment and decreases more in patients with DIPH. These contrast transit time changes can be detected in real time immediately after PED deployment.

  13. Successful well test application of portable multi-phase flow meter for high gas-volume and high water-cut wells in east Kalimantan, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Kaura, Jiten D.; Finley, D.B. [PT Halliburton Indonesia, Jakarta (Indonesia); Sudradjat, Wangsa; Riyanto, Latief [Tota E and P Indonesie, Jakarta (Indonesia); Halverson, Martin [FlowSys AS, Bergen (Norway)

    2004-07-01

    Recently, testing was needed on production wells in East Kalimantan. The wells were in a mature field, and productivity from the wells field featured high water cut (WC) and extremely high gas-volume fractions (GVF). The WC and GVF ranged from 80 to 100% and 90 to 100%, respectively. Moreover, most of the wells are low productivity so they are very sensitive to back-pressure. The high WC, high GVF and low-productivity from these wells in this area present an extreme challenge for accurate production measurement. Barges are commonly used to perform well services in the swamp area of this marginal field, and production allocations from wells in this difficult area were previously monitored and measured with conventional well-test equipment on-board a well testing barge. The well test equipment traditionally used requires a large footprint, and the associated flaring presents an environmental situation in this sensitive swamp area. Hence, the MPFM solution was chosen. To better meet the challenges presented by the testing conditions, a portable multiphase flow meter (MPFM) was chosen to perform the testing from the well-testing barge. For comparative purposes, the MPFM was installed on the barge immediately upstream of the well testing equipment. Initial measurements with the MPFM yielded results that were {+-} 30% of the test separator reading. A slight modification was introduced to the MPFM system in the form of a gas knock-out (GKO) vessel. Subsequent measurements with the modified MPFM system yielded readings that were {+-}10% of the test separator reading. (author)

  14. Room acoustic transition time based on reflection overlap

    DEFF Research Database (Denmark)

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

    2013-01-01

    at time t, which is mainly controlled by the absorption characteristics of the boundary surfaces of the room. Scattering, diffuse reflections, and diffraction, which facilitate the overlapping process, have not been taken into account. Measured impulse responses show that the transition occurs earlier......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...... in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions....

  15. Room acoustic transition time based on reflection overlap

    DEFF Research Database (Denmark)

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

    2010-01-01

    at time t, which is mainly controlled by the absorption characteristics of the boundary surfaces of the room. Scattering, diffuse reflections, and diffraction, which facilitate the overlapping process, have not been taken into account. Measured impulse responses show that the transition occurs earlier......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...... in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions....

  16. The effects of transit time heterogeneity on brain oxygenation during rest and functional activation

    Science.gov (United States)

    Rasmussen, Peter M; Jespersen, Sune N; Østergaard, Leif

    2015-01-01

    The interpretation of regional blood flow and blood oxygenation changes during functional activation has evolved from the concept of ‘neurovascular coupling', and hence the regulation of arteriolar tone to meet metabolic demands. The efficacy of oxygen extraction was recently shown to depend on the heterogeneity of capillary flow patterns downstream. Existing compartment models of the relation between tissue metabolism, blood flow, and blood oxygenation, however, typically assume homogenous microvascular flow patterns. To take capillary flow heterogeneity into account, we modeled the effect of capillary transit time heterogeneity (CTH) on the ‘oxygen conductance' used in compartment models. We show that the incorporation of realistic reductions in CTH during functional hyperemia improves model fits to dynamic blood flow and oxygenation changes acquired during functional activation in a literature animal study. Our results support earlier observations that oxygen diffusion properties seemingly change during various physiologic stimuli, and posit that this phenomenon is related to parallel changes in capillary flow patterns. Furthermore, our results suggest that CTH must be taken into account when inferring brain metabolism from changes in blood flow- or blood oxygenation-based signals . PMID:25492112

  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. 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.

  19. 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)

  20. 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®

  1. Transit timing effects due to an exomoon - II

    Science.gov (United States)

    Kipping, David M.

    2009-07-01

    In our previous paper, we evaluated the transit duration variation (TDV) effect for a co-aligned planet-moon system at an orbital inclination of i = 90°. Here, we will consider the effect for the more general case of i inclined from the planet-star plane by Euler rotation angles α,β and γ. We find that the TDV signal has two major components, one due to the velocity variation effect described in our first paper and one new component due to transit impact parameter variation. By evaluating the dominant terms, we find the two effects are additive for prograde exomoon orbits, and deductive for retrograde orbits. This asymmetry could allow for future determination of the orbital sense of motion. We re-evaluate the ratio of TDV and transit timing variation effects, η, in the more general case of an inclined planetary orbit with a circular orbiting moon and find that it is still possible to directly determine the moon's orbital separation from just the ratio of the two amplitudes, as first proposed in our previous paper.

  2. 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.

  3. Constipation and colonic transit times in children with morbid obesity.

    Science.gov (United States)

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

    2011-04-01

    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. Ninety-one children with morbid obesity ages 8 to 18 years, entering a prospective, randomized controlled study evaluating the effect of an outpatient versus inpatient treatment program of obesity, participated. All of the children filled out a standardized questionnaire regarding their bowel habits, and CTTs were measured using radioopaque markers. Food diaries were also recorded to evaluate their diet. A total of 19 children (21%) had functional constipation according to the Rome III criteria, whereas 1 child had functional nonretentive fecal incontinence. Total CTT exceeded 62 hours in only 10.5% of the children with constipation, and among them, 2 had a total CTT of >100 hours. In the nonconstipated group 8.3% had a delayed CTT. Furthermore, no difference was found between the diet of children with or without constipation, specifically not with respect to fiber and fat intake. Our study confirms a high frequency of functional constipation in children with obesity, using the Rome III criteria. However, abnormal colonic motility, as measured by CTT, was delayed in only a minority of patients. No relation was found between constipation in these children and fiber or fat intake.

  4. Advanced Instrumentation for Molten Salt Flow Measurements at NEXT

    Science.gov (United States)

    Tuyishimire, Olive

    2017-09-01

    The Nuclear Energy eXperiment Testing (NEXT) Lab at Abilene Christian University is building a Molten Salt Loop to help advance the technology of molten salt reactors (MSR). NEXT Lab's aim is to be part of the solution for the world's top challenges by providing safe, clean, and inexpensive energy, clean water and medical Isotopes. Measuring the flow rate of the molten salt in the loop is essential to the operation of a MSR. Unfortunately, there is no flow meter that can operate in the high temperature and corrosive environment of a molten salt. The ultrasonic transit time method is proposed as one way to measure the flow rate of high temperature fluids. Ultrasonic flow meter uses transducers that send and receive acoustic waves and convert them into electrical signals. Initial work presented here focuses on the setup of ultrasonic transducers. This presentation is the characterization of the pipe-fluid system with water as a baseline for future work.

  5. 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.

  6. 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

  7. 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.

  8. 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

    based on a gamma-variate model of the capillary transit time distribution. In addition, we wanted to investigate if a subtle increase of the blood–brain barrier permeability can be incorporated into the model, still allowing estimation of CTH. Materials and Methods: Twenty-three healthy subjects were...... scanned at 3.0T MRI system applying DCE-MRI and using a gamma-variate model to estimate CTH as well as cerebral blood flow (CBF), cerebral blood volume (CBV), and permeability of the blood–brain barrier, measured as the influx constant Ki. For proof of principle we also investigated three patients...... response function. Conclusion: Our results open the possibility of characterizing brain perfusion by the capillary transit time distribution using DCE-MRI, theoretically a determinant of efficient blood to brain transport of important substances. Level of Evidence: 2. J. MAGN. RESON. IMAGING 2017;45:1809–1820....

  9. 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

    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 sequencingand their urine metabolome by ultra performance liquid chromatography mass spectrometry. Based...... on correlation analyses,we show that colonic transit time is associated with overall gutmicrobial composition, diversity and metabolism. A relatively prolonged colonic transit time associates with high microbial species richness and a shift in colonic metabolismfrom carbohydrate fermentation to protein...

  10. 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...... 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...... on correlation analyses, we show that colonic transit time is associated with overall gut microbial composition, diversity and metabolism. A relatively prolonged colonic transit time associates with high microbial species richness and a shift in colonic metabolism from carbohydrate fermentation to protein...

  11. Modeling hyporheic exchange and in-stream transport with time-varying transit time distributions

    Science.gov (United States)

    Ball, A.; Harman, C. J.; Ward, A. S.

    2014-12-01

    Transit time distributions (TTD) are used to understand in-stream transport and exchange with the hyporheic zone by quantifying the probability of water (and of dissolved material) taking time T to traverse the stream reach control volume. However, many studies using this method assume a TTD that is time-invariant, despite the time-variability of the streamflow. Others assume that storage is 'randomly sampled' or 'well-mixed' with a fixed volume or fixed exchange rate. Here we present a formulation for a time-variable TTD that relaxes both the time-invariant and 'randomly sampled' assumptions and only requires a few parameters. The framework is applied to transient storage, representing some combination of in-stream and hyporheic storage, along a stream reach. This approach does not assume that hyporheic and dead-zone storage is fixed or temporally-invariant, and allows for these stores to be sampled in more physically representative ways determined by the system itself. Instead of using probability distributions of age, probability distributions of storage (ranked by age) called Ω functions are used to describe how the off-stream storage is sampled in the outflow. Here the Ω function approach is used to describe hyporheic exchange during diurnal fluctuations in streamflow in a gaining reach of the H.J. Andrews Experimental Forest. The breakthrough curves of salt slugs injected four hours apart over a 28-hour period show a systematic variation in transit time distribution. This new approach allows us to relate these salt slug TTDs to a corresponding time-variation in the Ω function, which can then be related to changes in in-stream storage and hyporheic zone mobilization under varying flow conditions. Thus, we can gain insights into how channel storage and hyporheic exchange are changing through time without having to specify difficult to measure or unmeasurable quantities of our system, such as total storage.

  12. 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 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...

  13. Your Glucose Meter

    Science.gov (United States)

    ... Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco ... 164KB) En Español Basic Facts 7 Tips for Testing Your Blood Sugar and Caring for Your Meter ...

  14. 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.

  15. Colonic transit time and pressure based on Bernoulli’s principle

    Science.gov (United States)

    Uno, Yoshiharu

    2018-01-01

    Purpose 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. Methods 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. Results 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. Conclusion The CTT and HAPC can be explained by Bernoulli’s principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics. PMID:29670388

  16. 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...... in eight healthy subjects. Neither mean small-intestinal nor mean orocaecal transit times of the radiolabelled marker were correlated with the magnitude of hydrogen peak, hydrogen peak time, or the area under hydrogen curve. No correlation was noted between whole-gut transit time of the radiolabelled...... marker and mean whole-gut transit time calculated from a 6-day administration of the radiopaque marker in 16 healthy subjects. The stool weight was inversely correlated with the mean colonic (r = -0.46, p = 0.009) and the mean whole-gut (r = -0.45, p = 0.011) transit times of the radiolabelled marker...

  17. 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....

  18. Image based automatic water meter reader

    Science.gov (United States)

    Jawas, N.; Indrianto

    2018-01-01

    Water meter is used as a tool to calculate water consumption. This tool works by utilizing water flow and shows the calculation result with mechanical digit counter. Practically, in everyday use, an operator will manually check the digit counter periodically. The Operator makes logs of the number shows by water meter to know the water consumption. This manual operation is time consuming and prone to human error. Therefore, in this paper we propose an automatic water meter digit reader from digital image. The digits sequence is detected by utilizing contour information of the water meter front panel.. Then an OCR method is used to get the each digit character. The digit sequence detection is an important part of overall process. It determines the success of overall system. The result shows promising results especially in sequence detection.

  19. 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.

  20. 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.

  1. Net metering study of switching effects on electromechanical meters[Report prepared for the Measurement Canada Electricity Net Metering Project

    Energy Technology Data Exchange (ETDEWEB)

    Van Overberghe, L. [Measurement Canada, London, ON (Canada)

    2006-03-03

    The feasibility of introducing net metering in the electricity sector was evaluated with particular reference to a project administered by Measurement Canada and Electro-Federation Canada (MicroPower Connect) in collaboration with Natural Resources Canada. The objective of the Measurement Canada Electricity Net Metering Project is to identify and eliminate the barriers introduced by the Electricity and Gas Inspection Act regarding the introduction of net metering. The purpose was to design a device that would allow rotation reversal in a residential electromechanical single phase meter. The device should approximate any fluctuations found in a typical net metering system. A series of tests were conducted to understand the influences, on errors, of forward-to-reverse and reverse-to-forward transitions, specifically to find evidence of error migration and mechanical stress. The project was designed to find and measure the effects of forward reverse switching on an electromechanical meter resulting from a change in energy flow. Twenty metres were calibrated in the forward direction in series from light load to high load. Power factor was not adjustable. Test points were then applied in both the forward and reverse directions. The exercise yielded individual errors which were aggregated to show average found errors after 3,000 transitions. Small shifts in errors were apparent and there was no evidence to support a disk flutter theory. refs., tabs., figs.

  2. Conducted interference on smart meters

    NARCIS (Netherlands)

    Keyer, Cornelis H.A.; Leferink, Frank

    2017-01-01

    The increasing conducted interference caused by modern electronic equipment is causing more problems for electronic, or static, energy meters. These meters are called smart meters when equipped with a communication link, and are replacing the conventional electromechanical meters. It is known that

  3. Estimation of transit times in a Karst Aquifer system using environmental tracers: Application on the Jeita Aquifer system-Lebanon.

    Science.gov (United States)

    Doummar, Joanna; Hamdan, Ahmad

    2016-04-01

    Estimating transit times is essential for the assessment of aquifer vulnerability to contaminants. Groundwater in karst aquifer is assumed to be relatively young due to fast preferential pathways; slow flow components are present in water stored in the fissured matrix. Furthermore, transit times are site specific as they depend on recharge rates, temperatures, elevation, and flow media; saturated and unsaturated zones. These differences create significant variation in the groundwater age in karst systems as the water sampled will be a mix of different water that has been transported through different flow pathways (fissured matrix and conduits). Several methods can be applied to estimate water transit time of an aquifer such as artificial tracers, which provide an estimate for fast flow velocities. In this study, groundwater residence times in the Jeita spring aquifer (Lebanon) were estimated using several environmental tracers such as Chlorofluorocarbons (CFCs), Sulfur Hexafluoride (SF6), Helium-Tritium (3H, 3H- 3He). Additional stable isotope and major ion analysis was performed to characterize water types. Groundwater samples were collected from six different wells in the Jeita catchment area (Jurassic Kesrouane aquifer) as well as from the spring and cave itself. The results are reproducible for the Tritium-Helium method, unlike for the CFC/SF6 methods that yielded poor results due to sampling problems. Tritium concentrations in all groundwater samples show nearly the same concentration (~2.73 TU) except for one sample with relatively lower tritium concentration (~2.26 TU). Ages ranging from 0.07 ± 0.07 years to 23.59 ± 0.00 years were obtained. The youngest age is attributed to the spring/ cave while the oldest ages were obtained in wells tapping the fissured matrix. Neon in these samples showed considerable variations and high delta Ne in some samples indicating high excess air. Four (4) samples showed extreme excess air (Delta-Ne is greater than 70 %) and

  4. 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

  5. Carbon activity meter

    International Nuclear Information System (INIS)

    Roy, P.; Krankota, J.L.

    1975-01-01

    A carbon activity meter utilizing an electrochemical carbon cell with gaseous reference electrodes having particular application for measuring carbon activity in liquid sodium for the LMFBR project is described. The electrolyte container is electroplated with a thin gold film on the inside surface thereof, and a reference electrode consisting of CO/CO 2 gas is used. (U.S.)

  6. Meter Designs Reduce Operation Costs for Industry

    Science.gov (United States)

    2013-01-01

    Marshall Space Flight Center collaborated with Quality Monitoring and Control (QMC) of Humble, Texas, through a Space Act Agreement to design a balanced flow meter for the Space Shuttle Program. QMC founded APlus-QMC LLC to commercialize the technology, which has contributed to 100 new jobs, approximately $250,000 in yearly sales, and saved customers an estimated $10 million.

  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. Runoff Generation Mechanisms and Mean Transit Time in a High-Elevation Tropical Ecosystem

    Science.gov (United States)

    Mosquera, G.

    2015-12-01

    Understanding runoff generation processes in tropical mountainous regions remains poorly understood, particularly in ecosystems above the tree line. Here, we provide insights on the process dominating the ecohydrology of the tropical alpine biome (i.e., páramo) of the Zhurucay River Ecohydrological Observatory. The study site is located in south Ecuador between 3400-3900 m in elevation. We used a nested monitoring system with eight catchments (20-753 ha) to measure hydrometric data since December 2010. Biweekly samples of rainfall, streamflow, and soil water at low tension were collected for three years (May 2011-May2014) and analyzed for water stable isotopes. We conducted an isotopic characterization of rainfall, streamflow, and soil waters to investigate runoff generation. These data were also integrated into a lumped model to estimate the mean transit time (MTT) and to investigate landscape features that control its variability. The isotopic characterization evidenced that the water stored in the shallow organic horizon of the Histosol soils (Andean wetlands) located near the streams is the major contributor of water to the streams year-round, whereas the water draining through the hillslope soils, the Andosols, regulates discharge by recharging the wetlands at the valley bottoms. The MTT evaluation indicated relatively short MTTs (0.15-0.73 yr) linked to short subsurface flow paths of water. We also found evidence for topographic controls on the MTT variability. These results reveal that: 1) the ecohydrology of this ecosystem is dominated by shallow subsurface flow in the organic horizon of the soils and 2) the combination of the high storage capacity of the Andean wetlands and the slope of the catchments controls runoff generation and the high water regulation capacity of the ecosystem.

  9. 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

  10. 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.

  11. Transit Timing Observations from Kepler. VI. Potentially Interesting Candidate Systems from Fourier-based Statistical Tests

    OpenAIRE

    Steffen, Jason H.; Ford, Eric B.; Rowe, Jason F.; Fabrycky, Daniel C.; Holman, Matthew J.; Welsh, WIlliam F.; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Ciardi, David R.; Jenkins, Jon M.; Kjeldsen, Hans; Koch, David G.; 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 (Q6) 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 sy...

  12. An Estimate of the Global Ocean Transit Time Distribution Computed With an Eddy Rich General Circulation Model

    Science.gov (United States)

    Bryan, F. O.; Maltrud, M.; Peacock, S.; Lindsay, K.

    2008-12-01

    Transit time distributions (TTDs), or age spectra, provide a powerful conceptual framework for evaluating and interpreting the advective-diffusive transport properties of geophysical flows. Most calculations and practical applications of TTDs to date have considered only the case of steady circulations with parameterized turbulent mixing. We have computed the first decades of the global ocean TTD for the unsteady, but statistically stationary, flow using an ensemble of impulse boundary propagators in an eddy-rich general ciculation model. In this presentation we will provide an overview of the geographical and temporal structure of the computed TTD, consider the convergence properties of the TTD as a function of ensemble size, space-time coarsening, and lag time, and consider the utility of TTDs as a metric for testing eddy mixing parameterizations in coarse resolution models.

  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. 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.

  15. Development of the impedance void meter

    International Nuclear Information System (INIS)

    Chung, Moon Ki; Song, Chul Hwa; Won, Soon Yeon; Kim, Bok Deuk

    1994-06-01

    An impedance void meter is developed to measure the area-averaged void fraction. Its basic principle is based on the difference in the electrical conductivity between phases. Several methods of measuring void fraction are briefly reviewed and the reason why this type of void meter is chosen to develop is discussed. Basic principle of the measurement is thoroughly described and several design parameters to affect the overall function are discussed in detail. As example of applications is given for vertical air-water flow. It is shown that the current design has good dynamic response as well as very fine spatial resolution. (Author) 47 refs., 37 figs

  16. Digital Capacitance Meter

    OpenAIRE

    Indra Budi Cahya Ardi; Luyung Dinaini Skom, MM

    2002-01-01

    This thesis explores the design, build, analyze the work circuit, and test a series ofDigital Capacitance Meter. It works by using two monostable multivibrator as shownon the input from the output through seven segment indicator. As the source voltageused 9-volt battery.This tool is used to determine condition and capacity of a capacitor in the variousunits, namely: Pikko farad (pF), nano-farad (nF), micro and milli farad farad (MF).

  17. Mean transit times in headwater catchments: insights from the Otway Ranges, Australia

    Science.gov (United States)

    Howcroft, William; Cartwright, Ian; Morgenstern, Uwe

    2018-01-01

    Understanding the timescales of water flow through catchments and the sources of stream water at different flow conditions is critical for understanding catchment behaviour and managing water resources. Here, tritium (3H) activities, major ion geochemistry and streamflow data were used in conjunction with lumped parameter models (LPMs) to investigate mean transit times (MTTs) and the stores of water in six headwater catchments in the Otway Ranges of southeastern Australia. 3H activities of stream water ranged from 0.20 to 2.14 TU, which are significantly lower than the annual average 3H activity of modern local rainfall, which is between 2.4 and 3.2 TU. The 3H activities of the stream water are lowest during low summer flows and increase with increasing streamflow. The concentrations of most major ions vary little with streamflow, which together with the low 3H activities imply that there is no significant direct input of recent rainfall at the streamflows sampled in this study. Instead, shallow younger water stores in the soils and regolith are most likely mobilised during the wetter months. MTTs vary from approximately 7 to 230 years. Despite uncertainties of several years in the MTTs that arise from having to assume an appropriate LPM, macroscopic mixing, and uncertainties in the 3H activities of rainfall, the conclusion that they range from years to decades is robust. Additionally, the relative differences in MTTs at different streamflows in the same catchment are estimated with more certainty. The MTTs in these and similar headwater catchments in southeastern Australia are longer than in many catchments globally. These differences may reflect the relatively low rainfall and high evapotranspiration rates in southeastern Australia compared with headwater catchments elsewhere. The long MTTs imply that there is a long-lived store of water in these catchments that can sustain the streams over drought periods lasting several years. However, the catchments are likely

  18. Flowrate measurements in closed pipes by the method of transit time measurement. Pt.1 Method of transit time of a radioactive tracer

    International Nuclear Information System (INIS)

    Dubail, A.; Favennec, J.M.

    1982-01-01

    Classical methods of flowrate measuring in closed pipes generally make use of indirect principles (for example: the measurements of the pressure loss through an orifice plate). Absolute or fundamental methods of the measurements of volume and time allow the ''in situ'' calibration and control of flowmeters in their nominal conditions of use. The method of transit-time measurements by fast injection of a radioactive tracer is described and analyzed [fr

  19. Streamlining Smart Meter Data Analytics

    OpenAIRE

    Liu, Xiufeng; Nielsen, Per Sieverts

    2015-01-01

    Today smart meters are increasingly used in worldwide. Smart meters are the advanced meters capable of measuring customer energy consumption at a fine-grained time interval, e.g., every 15 minutes. The data are very sizable, and might be from different sources, along with the other social-economic metrics such as the geographic information of meters, the information about users and their property, geographic location and others, which make the data management very complex. On the other hand, ...

  20. Net metering: zero electricity bill

    International Nuclear Information System (INIS)

    Mangi, A.; Khan, Z.

    2011-01-01

    Worldwide move towards renewable energy sources, environmental concerns and decentralization of the power sector have made net metering an attractive option for power generation at small scale. This paper discusses the net metering, economical issues of renewable sources in Pakistan, technical aspects, installation suitability according to varying terrain, existing utility rules and formulation of legislation for net metering making it economically attractive. (author)

  1. Smart metering design and applications

    CERN Document Server

    Weranga, K S K; Chandima, D P

    2013-01-01

    Taking into account the present day trends and the requirements, this Brief focuses on smart metering of electricity for next generation energy efficiency and conservation. The contents include discussions on the smart metering concepts and existing technologies and systems as well as design and implementation of smart metering schemes together with detailed examples.

  2. Good standards for smart meters

    NARCIS (Netherlands)

    Hoenkamp, R.A.; Huitema, G.B.

    2012-01-01

    This paper examines what lessons can be learned from the rollout of smart meters in the Netherlands to improve the European smart meter standardization. This study is based on the case of the Dutch meter rollout which preparations started in 2005 but finally was delayed until 2011 by governmental

  3. Advanced metering techniques

    Energy Technology Data Exchange (ETDEWEB)

    Szydlowski, R.F.

    1993-01-01

    The goal of the US Department of Energy Federal Energy Management Program (FEMP) is to facilitate energy-efficiency improvements at federal facilities. This is accomplished by a balanced program of technology development, facility assessment, and use of cost-sharing procurement mechanisms. Technology development focuses upon the tools and procedures used to identify and evaluate efficiency improvements. For facility assessment, FEMP provides metering equipment and trained analysts to federal agencies exhibiting a commitment to improve energy-use efficiency. To assist in implementing energy-efficiency measures, FEMP helps federal agencies with identifying efficiency opportunities and in implementing energy-efficiency and demand-side management programs at federal sites. As the lead laboratory for FEMP, Pacific Northwest Laboratory (PNL) provides technical assistance to federal agencies to better understand and characterize energy systems. The US Army Forces Command (FORSCOM) has tasked PNL to provide technical assistance to characterize and modernize energy systems at FORSCOM installations. As part of that technical assistance, PNL performed an in-depth examination of automatic meter-reading system technologies currently available. The operating characteristics and relative merits of all the major systems were reviewed in the context of applicability to federal installations. That review is documented in this report.

  4. 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

  5. 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.

  6. 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...

  7. The effect of conjunctions on the transit timing variations of exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Nesvorný, David [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Vokrouhlický, David, E-mail: davidn@boulder.swri.edu, E-mail: vokrouhl@cesnet.cz [Institute of Astronomy, Charles University, V Holešovičkách 2, CZ-18000 Prague 8 (Czech Republic)

    2014-07-20

    We develop an analytic model for transit timing variations produced by orbital conjunctions between gravitationally interacting planets. If the planetary orbits have tight orbital spacing, which is a common case among the Kepler planets, the effect of a single conjunction can be best described as: (1) a step-like change of the transit timing ephemeris with subsequent transits of the inner planet being delayed and those of the outer planet being sped up, and (2) a discrete change in sampling of the underlying oscillations from eccentricity-related interaction terms. In the limit of small orbital eccentricities, our analytic model gives explicit equations for these effects as a function of the mass and orbital separation of planets. We point out that a detection of the conjunction effect in real data is of crucial importance for the physical characterization of planetary systems from transit timing variations.

  8. Isotope specific arbitrary material flow meter

    Science.gov (United States)

    Barty, Christopher P. J.; Post, John C.; Jones, Edwin

    2016-10-25

    A laser-based mono-energetic gamma-ray source is used to provide non-destructive and non-intrusive, quantitative determination of the absolute amount of a specific isotope contained within pipe as part of a moving fluid or quasi-fluid material stream.

  9. Pulse-echo ultrasound transit time spectroscopy: A comparison of experimental measurement and simulation prediction.

    Science.gov (United States)

    Wille, Marie-Luise; Almualimi, Majdi A; Langton, Christian M

    2016-01-01

    Considering ultrasound propagation through complex composite media as an array of parallel sonic rays, a comparison of computer-simulated prediction with experimental data has previously been reported for transmission mode (where one transducer serves as transmitter, the other as receiver) in a series of 10 acrylic step-wedge samples, immersed in water, exhibiting varying degrees of transit time inhomogeneity. In this study, the same samples were used but in pulse-echo mode, where the same ultrasound transducer served as both transmitter and receiver, detecting both 'primary' (internal sample interface) and 'secondary' (external sample interface) echoes. A transit time spectrum was derived, describing the proportion of sonic rays with a particular transit time. A computer simulation was performed to predict the transit time and amplitude of various echoes created, and compared with experimental data. Applying an amplitude-tolerance analysis, 91.7% ± 3.7% of the simulated data were within ±1 standard deviation of the experimentally measured amplitude-time data. Correlation of predicted and experimental transit time spectra provided coefficients of determination (R(2)%) ranging from 100.0% to 96.8% for the various samples tested. The results acquired from this study provide good evidence for the concept of parallel sonic rays. Furthermore, deconvolution of experimental input and output signals has been shown to provide an effective method to identify echoes otherwise lost due to phase cancellation. Potential applications of pulse-echo ultrasound transit time spectroscopy include improvement of ultrasound image fidelity by improving spatial resolution and reducing phase interference artefacts. © IMechE 2015.

  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. 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.

  12. 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.

  13. 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....

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

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Ford, Eric B. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); 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. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Welsh, William F. [Astronomy Department, San Diego State University, San Diego, CA 92182-1221 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/California Institute of Technology, Pasadena, CA 91125 (United States); Kjeldsen, Hans [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Prsa, Andrej, E-mail: jsteffen@fnal.gov [Department of Astronomy and Astrophysics, Villanova University, 800 East Lancaster Avenue, Villanova, PA 19085 (United States)

    2012-09-10

    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.

  15. Field signatures of non-Fickian transport processes: transit time distributions, spatial correlations, reversibility and hydrogeophysical imaging

    Science.gov (United States)

    Le Borgne, T.; Kang, P. K.; Guihéneuf, N.; Shakas, A.; Bour, O.; Linde, N.; Dentz, M.

    2015-12-01

    Non-Fickian transport phenomena are observed in a wide range of scales across hydrological systems. They are generally manifested by a broad range of transit time distributions, as measured for instance in tracer breakthrough curves. However, similar transit time distributions may be caused by different origins, including broad velocity distributions, flow channeling or diffusive mass transfer [1,2]. The identification of these processes is critical for defining relevant transport models. How can we distinguish the different origins of non-Fickian transport in the field? In this presentation, we will review recent experimental developments to decipher the different causes of anomalous transport, based on tracer tests performed at different scales in cross borehole and push pull conditions, and time lapse hydrogeophysical imaging of tracer motion [3,4]. References:[1] de Anna-, P., T. Le Borgne, M. Dentz, A. M. Tartakovsky, D. Bolster, P. Davy (2013) Flow Intermittency, Dispersion and Correlated Continuous Time Random Walks in Porous Media, Phys. Rev. Lett., 110, 184502 [2] Le Borgne T., Dentz M., and Carrera J. (2008) Lagrangian Statistical Model for Transport in Highly Heterogeneous Velocity Fields. Phys. Rev. Lett. 101, 090601 [3] Kang, P. K., T. Le Borgne, M. Dentz, O. Bour, and R. Juanes (2015), Impact of velocity correlation and distribution on transport in fractured media : Field evidence and theoretical model, Water Resour. Res., 51, 940-959 [4] Dorn C., Linde N., Le Borgne T., O. Bour and L. Baron (2011) Single-hole GPR reflection imaging of solute transport in a granitic aquifer Geophys. Res. Lett. Vol.38, L08401

  16. E-meter with PLC-based automated meter reading

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, M. [Texas Instruments, Toronto, ON (Canada)

    2007-11-15

    Data can be transferred from electronic meters (e-meters) to a concentrator or other device in a variety of ways. However, new ways of communication are needed for automated meter reading (AMR) in order to avoid visits by utility officials to properties where meters are installed. In addition to remote meter reading, e-meters can have functions implemented to lower costs for electricity providers or to provide new features for end customers. This would only be possible if the meter could also receive data via a 2-way communication link. This article presented powerline communication (PLC), a completely different technique for AMR in which the power lines are used as the communication media. The major technologies used in PLC in Europe were discussed along with the challenges of overcoming quality problems. The ability to integrate all required functionality for a complex e-meter with PLC modem into small central processing units (CPUs) was also discussed. Texas Instruments offers a digital signal processor (DSP) that ensures reliable PLC. The way in which these microcomputers process electrical signals was also outlined in this article, with particular reference to how the information is made accessible for the CPUs and for metering devices. 3 figs.

  17. 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...

  18. 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...

  19. 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...

  20. Colonic transit time in constipated children: does pediatric slow-transit constipation exist?

    NARCIS (Netherlands)

    Benninga, M. A.; Büller, H. A.; Tytgat, G. N.; Akkermans, L. M.; Bossuyt, P. M.; Taminiau, J. A.

    1996-01-01

    In adults, slow-transit constipation is a well-established form of constipation with abdominal pain and an empty rectum on examination. Marker studies in these patients, mainly women, show a markedly slowed transit time in all colonic segments. No studies in constipated children are available that

  1. 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)

  2. Influence of Convective Effect of Solar Winds on the CME Transit Time

    Science.gov (United States)

    Sun, Lu-yuan

    2017-10-01

    Based on an empirical model for predicting the transit time of coronal mass ejections (CMEs) proposed by Gopalswamy, 52 CME events which are related to the geomagnetic storms of Dst Dst < -200 nT) in 1996- 2007 are selected, and combined with the observational data of the interplanetary solar winds that collected by the ACE satellite at 1AU, to analyze the influence of convective effect of ambient solar winds on the prediction of the CME transit time when it arrives at a place of 1 AU. After taking the convective effect of ambient solar winds into account, the standard deviation of predictions is reduced from 16.5 to 11.4 hours for the 52 CME events, and the prediction error is less than 15 hours for 68% of these events; while the standard deviation of predictions is reduced from 10.6 to 6.5 hours for the 10 CME events that caused extremely strong geomagnetic storms, and the prediction error is less than 5 hours for 6 of the 10 events. These results show that taking the convective effect of ambient solar winds into account can reduce the standard deviation of the predicted CME transit time, hence the convective effect of solar winds plays an important role for predicting the transit times of CME events.

  3. 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

  4. 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…

  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. Micro-gen metering solutions

    Energy Technology Data Exchange (ETDEWEB)

    Elland, J.; Dickson, J.; Cranfield, P.

    2003-07-01

    This report summarises the results of a project to investigate the regulation of domestic electricity metering work and identify the most economic options for micro-generator installers to undertake work on electricity meters. A micro-generation unit is defined as an energy conversion system converting non-electrical energy into electrical energy and can include technologies such as photovoltaic systems, small-scale wind turbines, micro-hydroelectric systems, and combined heat and power systems. Details of six tasks are given and cover examination of the existing framework and legal documentation for metering work, the existing technical requirements for meter operators, meter operator personnel accreditation, appraisal of options for meter changes and for micro-generation installation, document change procedures, industry consultation, and a review of the costs implications of the options.

  7. Comparison of Different Control Schemes for Strategic Departure Metering

    Science.gov (United States)

    Idris, Husni; Shen, Ni; Saraf, Aditya; Bertino, Jason; Zelinski, Shannon

    2016-01-01

    Airports and their terminal airspaces are key choke points in the air transportation system causing major delays and adding to pollution. A solution aimed at mitigating these chokepoints integrates the scheduling of runway operations, flight release from the gates and ramp into the airport movement area, and merging with other traffic competing for downstream airspace points. Within this integrated concept, we present a simulation-based analysis of the departure metering process, which delays the release of flights into the airport movement area while balancing two competing objectives: (1) maintaining large enough queues at the airport resources to maximize throughput and (2) absorbing excess delays at the gates or in ramp areas to save on fuel consumption, emissions, noise, and passenger discomfort. Three metering strategies are compared which respectively attempt to control the number of flights that (1) left the gate but did not take off, (2) left the ramp but did not take off, and (3) spent their unimpeded transit time to the runway but did not take off. It was observed that under deterministic and demand uncertainty conditions, the first strategy performed better than the other two strategies in terms of maintaining the runway throughput while transferring a significant average delay of two minutes to the gate. On the other hand, under uncertainties of flight transit time and runway service rate, all the strategies struggled to delay flights at the gate without a significant impact on the runway throughput.

  8. 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.

  9. 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.

  10. 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.

  11. Relative renal uptake and transit time measurements using functional factor images and fuzzy regions of interest

    International Nuclear Information System (INIS)

    Samal, M.; Nimmon, C.C.; Britton, K.E.; Bergmann, H.

    1998-01-01

    The aim of the study was a quantitative comparison of relative renal uptake and both the whole-kidney and the parenchymal transit time derived from factor analysis of image sequences and provided by standard clinical procedures. In order to extract the stable, well-interpretable factors, factor analysis was performed locally in the problem-specific time and spatial windows and the resulting factor images either evaluated directly as functional images or used as fuzzy regions of interest (ROIs) for the subsequent extraction of time-activity curves from the analysed data. The values of relative renal uptake of the left kidney measured in the functional factor images. Whole-kidney transit time calculated using fuzzy ROI curves correlated well with the reference values; however, both its mean value (336.5 s) and the standard deviation (151.5 s) were substantially greater than those of the values provided by a standard procedure. Parenchymal transit time calculated using ROI curves correlated better with the transit time through a wider corticomedullary region rather than through a narrow cortical region, which is decisive in a differential diagnosis of renal disorders. In general, values of transit times provided by factor analysis correlated well with those provided by reference methods but with a shift towards the higher numerical values. Results of the study provide quantitative evidence that the factor analysis of dynamic data may yield clinically relevant information. However, some basic requirements have to be fullfilled if the method is to be successfully applied clinically.(orig./MG) (orig.)

  12. Weather Impact on Airport Arrival Meter Fix Throughput

    Science.gov (United States)

    Wang, Yao

    2017-01-01

    Time-based flow management provides arrival aircraft schedules based on arrival airport conditions, airport capacity, required spacing, and weather conditions. In order to meet a scheduled time at which arrival aircraft can cross an airport arrival meter fix prior to entering the airport terminal airspace, air traffic controllers make regulations on air traffic. Severe weather may create an airport arrival bottleneck if one or more of airport arrival meter fixes are partially or completely blocked by the weather and the arrival demand has not been reduced accordingly. Under these conditions, aircraft are frequently being put in holding patterns until they can be rerouted. A model that predicts the weather impacted meter fix throughput may help air traffic controllers direct arrival flows into the airport more efficiently, minimizing arrival meter fix congestion. This paper presents an analysis of air traffic flows across arrival meter fixes at the Newark Liberty International Airport (EWR). Several scenarios of weather impacted EWR arrival fix flows are described. Furthermore, multiple linear regression and regression tree ensemble learning approaches for translating multiple sector Weather Impacted Traffic Indexes (WITI) to EWR arrival meter fix throughputs are examined. These weather translation models are developed and validated using the EWR arrival flight and weather data for the period of April-September in 2014. This study also compares the performance of the regression tree ensemble with traditional multiple linear regression models for estimating the weather impacted throughputs at each of the EWR arrival meter fixes. For all meter fixes investigated, the results from the regression tree ensemble weather translation models show a stronger correlation between model outputs and observed meter fix throughputs than that produced from multiple linear regression method.

  13. New Approaches to Assessing and Predicting the Hydrologic Impacts of Urban Disturbance Using Isotopes and Transit Time Analysis

    Science.gov (United States)

    Soulsby, C.; Geris, J.; Birkel, C.; Tetzlaff, D.

    2015-12-01

    Urbanization is an abrupt hydrological disturbance that affects large parts of the world. For ameliorative management, an understanding of how flow partitioning and storage dynamics are affected is crucial, yet this remains limited. This reflects the lack of integrated monitoring and modelling frameworks for characterizing these hydrological response dynamics to incremental urban development. Here we use a coupled flow-isotope model to assess the impacts of urbanisation (~20%) on stream water age distributions in an 8 km2 catchment. A conceptual runoff model was used with flux tracking to estimate the time-varying age of stream water at the outlet and both urban and non-urban sub-catchments over a 3 year period. Combined objective functions of both flow and isotope metric constrained model structures, improved calibration and aided model evaluation. Specifically, we explored (1) the age distribution of stream water draining urban and non-urban areas, (2) the integrated effect of these different land uses at larger catchment scales, and (3) how the modelling can predict the impacts on the stream water age of future urbanization proposals. The results showed that stream water draining the most urbanized tributary was youngest with a mean transit time (MTT) of sustainable urban water design in terms of targeted restriction of rapid water fluxes.

  14. 77 FR 40586 - Draft NIST Interagency Report (NISTIR) 7823, Advanced Metering Infrastructure Smart Meter...

    Science.gov (United States)

    2012-07-10

    ...-01] Draft NIST Interagency Report (NISTIR) 7823, Advanced Metering Infrastructure Smart Meter... Technology (NIST) seeks comments on Draft NISTIR 7823, Advanced Metering Infrastructure Smart Meter... (AMI) Smart Meters. The target audience for Draft NISTIR 7823 includes numerous stakeholders in the...

  15. Digital reactivity meter

    International Nuclear Information System (INIS)

    Copie, M.; Valantic, B.

    1978-01-01

    Digital reactivity meters (DRM) are mostly used as measuring instruments, e.g. for calibration of control rods, and there are only a few cases of their incorporation into the control systems of the reactors. To move in this direction there is more development work needed. First of all, fast algorithms are needed for inverse kinetics equations to relieve the computer for more important tasks of reactor model solving in real time. The next problem, currently under investigation, is the incorporation of the reactor thermal-hydraulic model into the DRM so that it can be used in the power range. Such an extension of DHM allows presentation not only of the instantaneous reactivity of the system, but also the inserted reactivity can be estimated from the temperature reactivity feed-backs. One of the applications of this concept is the anomalous digital reactivity monitor (ADRN) as part of the reactor protection system. As a solution of the first problem, a fast algorithm for solving the inverse kinetics equations has been implemented in the off-line program RODCAL on CDC 1700 computer and tested for its accuracy by performing different control rod calibrations on the reactor TRIGA

  16. An alternative arrangement of metered dosing fluid using centrifugal pump

    Science.gov (United States)

    Islam, Md. Arafat; Ehsan, Md.

    2017-06-01

    Positive displacement dosing pumps are extensively used in various types of process industries. They are widely used for metering small flow rates of a dosing fluid into a main flow. High head and low controllable flow rates make these pumps suitable for industrial flow metering applications. However their pulsating flow is not very suitable for proper mixing of fluids and they are relatively more expensive to buy and maintain. Considering such problems, alternative techniques to control the fluid flow from a low cost centrifugal pump is practiced. These include - throttling, variable speed drive, impeller geometry control and bypass control. Variable speed drive and impeller geometry control are comparatively costly and the flow control by throttling is not an energy efficient process. In this study an arrangement of metered dosing flow was developed using a typical low cost centrifugal pump using bypass flow technique. Using bypass flow control technique a wide range of metered dosing flows under a range of heads were attained using fixed pump geometry and drive speed. The bulk flow returning from the system into the main tank ensures better mixing which may eliminate the need of separate agitators. Comparative performance study was made between the bypass flow control arrangement of centrifugal pump and a diaphragm type dosing pump. Similar heads and flow rates were attainable using the bypass control system compared to the diaphragm dosing pump, but using relatively more energy. Geometrical optimization of the centrifugal pump impeller was further carried out to make the bypass flow arrangement more energy efficient. Although both the systems run at low overall efficiencies but the capital cost could be reduced by about 87% compared to the dosing pump. The savings in capital investment and lower maintenance cost very significantly exceeds the relatively higher energy cost of the bypass system. This technique can be used as a cost effective solution for

  17. 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.

  18. 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

  19. 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.

  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. Total and Segmental Colon Transit Time Study in Functional Constipation: Comparison With Healthy Subjects

    OpenAIRE

    Bhate, Prasad A.; Patel, Jatin A.; Parikh, Pathik; Ingle, Meghraj A.; Phadke, Anniruddha; Sawant, Prabha D.

    2015-01-01

    Background Constipation is a common problem worldwide. Constipation can be primary or secondary. Primary constipation is subdivided in slow transit constipation, normal transit constipation, and dyssynergic defecation. Colon transit time (CTT) is the most basic and primary tool in evaluating disorders of colonic motility. CTT helps to differentiate between types of constipation and plan the treatment. Methods Fifty functional constipation patients and 25 healthy controls were asked to ingest ...

  2. Noise Performance of Millimeter-wave Silicon Based Mixed Tunneling Avalanche Transit Time(MITATT) Diode

    OpenAIRE

    Aritra Acharyya; Moumita Mukherjee; J. P. Banerjee

    2010-01-01

    A generalized method for small-signal simulation of avalanche noise in Mixed Tunneling Avalanche Transit Time (MITATT) device is presented in this paper where the effect of series resistance is taken into account. The method is applied to a millimeter-wave Double Drift Region (DDR) MITATT device based on Silicon to obtain noise spectral density and noise measure as a function of frequency for different values of series resistance. It is found that noise measure of the dev...

  3. 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) value of σ is that the stellar 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.

  4. Bayesian Nonparametric Estimation for Dynamic Treatment Regimes with Sequential Transition Times.

    Science.gov (United States)

    Xu, Yanxun; Müller, Peter; Wahed, Abdus S; Thall, Peter F

    2016-01-01

    We analyze a dataset arising from a clinical trial involving multi-stage chemotherapy regimes for acute leukemia. The trial design was a 2 × 2 factorial for frontline therapies only. Motivated by the idea that subsequent salvage treatments affect survival time, we model therapy as a dynamic treatment regime (DTR), that is, an alternating sequence of adaptive treatments or other actions and transition times between disease states. These sequences may vary substantially between patients, depending on how the regime plays out. To evaluate the regimes, mean overall survival time is expressed as a weighted average of the means of all possible sums of successive transitions times. We assume a Bayesian nonparametric survival regression model for each transition time, with a dependent Dirichlet process prior and Gaussian process base measure (DDP-GP). Posterior simulation is implemented by Markov chain Monte Carlo (MCMC) sampling. We provide general guidelines for constructing a prior using empirical Bayes methods. The proposed approach is compared with inverse probability of treatment weighting, including a doubly robust augmented version of this approach, for both single-stage and multi-stage regimes with treatment assignment depending on baseline covariates. The simulations show that the proposed nonparametric Bayesian approach can substantially improve inference compared to existing methods. An R program for implementing the DDP-GP-based Bayesian nonparametric analysis is freely available at https://www.ma.utexas.edu/users/yxu/.

  5. Smart Metering System for Microgrids

    DEFF Research Database (Denmark)

    Palacios-Garcia, Emilio; Guan, Yajuan; Savaghebi, Mehdi

    2015-01-01

    Smart meters are the cornerstone in the new conception of the electrical network or Smart Grid (SG), providing detailed information about users' energy consumption and allowing the suppliers to remotely collect data for billing. Nevertheless, their features are not only useful for the energy...... will expose an example of Smart Meters integration in a Microgrid scenario, which is the Intelligent Microgrid Lab of Aalborg University (AAU). To do this, first the installation available in the Microgrid Lab will be introduced. Then, three different test scenarios and their respective results...... will be presented, regarding the capabilities of this system and the advantages of integration the Smart Meters information in the Microgrid control....

  6. Automated borehole gravity meter system

    International Nuclear Information System (INIS)

    Lautzenhiser, Th.V.; Wirtz, J.D.

    1984-01-01

    An automated borehole gravity meter system for measuring gravity within a wellbore. The gravity meter includes leveling devices for leveling the borehole gravity meter, displacement devices for applying forces to a gravity sensing device within the gravity meter to bring the gravity sensing device to a predetermined or null position. Electronic sensing and control devices are provided for (i) activating the displacement devices, (ii) sensing the forces applied to the gravity sensing device, (iii) electronically converting the values of the forces into a representation of the gravity at the location in the wellbore, and (iv) outputting such representation. The system further includes electronic control devices with the capability of correcting the representation of gravity for tidal effects, as well as, calculating and outputting the formation bulk density and/or porosity

  7. Healthcare Energy Metering Guidance (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    This brochure is intended to help facility and energy managers plan and prioritize investments in energy metering. It offers healthcare-specific examples of metering applications, benefits, and steps that other health systems can reproduce. It reflects collaborative input from the U.S. Department of Energy national laboratories and the health system members of the DOE Hospital Energy Alliance's Benchmarking and Measurement Project Team.

  8. Transit timing observations from Kepler – VII. Confirmation of 27 planets in 13 multiplanet systems via transit timing variations and orbital stability

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States). Accelerator Physics Center; Fabrycky, Daniel C. [Lick Observ.; Agol, Eric [Washington U., Seattle; Ford, Eric B.; Morehead, Robert C. [Florida U.; Cochran, William D. [Texas U.; Lissauer, Jack J. [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Adams, Elisabeth R. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Borucki, William J. [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Bryson, Steve [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Caldwell, Douglas A. [SETI Inst., Mrn. View; Dupree, Andrea [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Jenkins, Jon M. [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Robertson, Paul [Texas U.; Rowe, Jason F. [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Seader, Shawn [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Thompson, Susan [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States); Twicken, Joseph D. [NASA Ames Research Center (ARC), Moffett Field, Mountain View, CA (United States)

    2012-10-27

    We confirm 27 planets in 13 planetary systems by showing the existence of statistically significant anti-correlated transit timing variations (TTVs), which demonstrates that the planet candidates are in the same system, and long-term dynamical stability, which places limits on the masses of the candidates---showing that they are planetary. %This overall method of planet confirmation was first applied to \\kepler systems 23 through 32. All of these newly confirmed planetary systems have orbital periods that place them near first-order mean motion resonances (MMRs), including 6 systems near the 2:1 MMR, 5 near 3:2, and one each near 4:3, 5:4, and 6:5. In addition, several unconfirmed planet candidates exist in some systems (that cannot be confirmed with this method at this time). A few of these candidates would also be near first order MMRs with either the confirmed planets or with other candidates. One system of particular interest, Kepler-56 (KOI-1241), is a pair of planets orbiting a 12th magnitude, giant star with radius over three times that of the Sun and effective temperature of 4900 K---among the largest stars known to host a transiting exoplanetary system.

  9. 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.

  10. Total and segmental colonic transit time in constipated patients with Chagas’ disease without megaesophagus or megacolon

    Directory of Open Access Journals (Sweden)

    S.L. Santos

    2000-01-01

    Full Text Available Manometric and pharmacological tests have shown that motor abnormalities may occur in the non-dilated colons of chagasic patients. In order to investigate the presence of abnormalities of colonic function in constipated patients with Chagas’ disease (ChC without megaesophagus or megacolon, studies of total and segmental colonic transit time with radiopaque markers were performed on 15 ChC patients, 27 healthy volunteers and 17 patients with idiopathic constipation (IC. The values obtained for the control group were similar to those reported in the literature (total colonic time: 34.1 ± 15.6 h; right colon: 9.9 ± 7.3 h; left colon: 10.8 ± 10 h, and rectosigmoid: 12.6 ± 9.9 h. Colonic transit time data permitted us to divide both IC and ChC patients into groups with normal transit and those with slow colonic transit. Colonic inertia was detected in 41% of IC patients and in 13% of ChC patients; left colon isolated stasis (hindgut dysfunction was detected in 12% of IC patients and 7% of ChC patients, and outlet obstruction was detected in 6% of IC patients and 7% of ChC patients. There were no significant differences in total or segmental colonic transit times between slow transit IC and slow transit ChC patients. In conclusion, an impairment of colonic motility was detected in about 30% of constipated patients with Chagas’ disease without megaesophagus or megacolon. This subgroup of patients presented no distinctive clinical feature or pattern of colonic dysmotility when compared to patients with slow transit idiopathic constipation.

  11. Hepatic vein transit time of SonoVue: a comparative study with Levovist.

    Science.gov (United States)

    Lim, Adrian K P; Patel, Nayna; Eckersley, Robert J; Goldin, Robert D; Thomas, Howard C; Cosgrove, David O; Taylor-Robinson, Simon D; Blomley, Martin J K

    2006-07-01

    To prospectively compare transit times of Levovist and SonoVue in healthy volunteers and patients with biopsy-proved hepatitis C-related liver disease. Institutional review board approval and informed consent were obtained. Forty patients and 25 healthy volunteers were examined. Subjects fasted, a bolus of SonoVue (0.6 mL) was injected into a cubital fossa vein, and hepatic venous time-intensity profiles were measured with spectral Doppler tracing. This was repeated with two injections of Levovist (2 g) and another injection of SonoVue. Time-intensity curves of spectral Doppler signals of right and middle hepatic veins were analyzed. A sustained signal intensity increase of 10% above baseline levels indicated hepatic vein transit time (HVTT). Carotid artery audio intensity was measured in volunteers. Analysis of variance and t tests were used for statistical analysis. Twelve patients had mild hepatitis; 18, moderate or severe hepatitis; and 10, cirrhosis. Mean HVTTs in control, mild hepatitis, moderate or severe hepatitis, and cirrhosis groups were 38.3 seconds +/- 2.4 (standard error), 47.5 seconds +/- 6.5, 29.5 seconds +/- 10.8, and 17.6 seconds +/- 5.0, respectively, with Levovist (P SonoVue (P SonoVue; however, there were significant differences in HVTT between all patient groups with Levovist. HVTT of SonoVue was shorter than that of Levovist in all groups (P SonoVue or Levovist (9.1 seconds +/- 2.4 [standard error] and 8.4 seconds +/- 2.5, respectively, P = .18). HVTT was significantly shorter with SonoVue than with Levovist; there was no significant difference in cardiopulmonary transit time. RSNA, 2006

  12. 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.

  13. 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

  14. 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

  15. Novel computation of pulse transit time from multi-channel PPG signals by wavelet transform

    Directory of Open Access Journals (Sweden)

    Pielmuş Alexandru-Gabriel

    2016-09-01

    Full Text Available Being able to accurately monitor blood pressure in a reliable, truly non-invasive manner is a highly sought after goal within the biomedical community. In this paper we propose and assess a system, methodology and algorithm for unobtrusively obtaining true pulse transit time data from readily accessible peripheral locations, such as the hand, using a highly synchronous body-sensor-network encompassing an electrocardiogram- and dual mode photoplethysmogram sensor node. The results suggest the feasibility of acquiring such data, which strongly correlates with the recorded reference blood pressure, and can therefore be further employed to track changes thereof.

  16. 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.

  17. Checking liquid meters. Marketers find ''master meter program'' provides reliable, economical method to check truck meters

    Energy Technology Data Exchange (ETDEWEB)

    Lady, P.

    1976-08-01

    With LP-gas prices continuing to increase, LP-gas marketers are becoming increasingly aware of the need for testing liquid meters on trucks used for delivering bulk propane. Many large marketers are aware of the need for consistent testing and are establishing periodic programs for their truck fleets. Because the official test equipment--the volumetric meter power--is expensive and requires a highly trained operator, many dealers are seeking simpler, less expensive testing methods to make sure that their meters are dispensing fuel. The more accurate of the two alternative methods is a master meter which has been calibrated against a prover and whose variations are known for different flow rates. The method's main disadvantage is the possibility that the master meter might be in error. The last method, which uses truck scales, is the least expensive and most readily available to all operators but also is the least accurate and is time-consuming, especially in low-flow tests.

  18. Effects of anatomical position on esophageal transit time: A biomagnetic diagnostic technique

    Science.gov (United States)

    Cordova-Fraga, Teodoro; Sosa, Modesto; Wiechers, Carlos; la Roca-Chiapas, Jose Maria De; Moreles, Alejandro Maldonado; Bernal-Alvarado, Jesus; Huerta-Franco, Raquel

    2008-01-01

    AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI). METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the ETT was assessed in three anatomical positions (at upright, fowler, and supine positions; 90º, 45º and 0º, respectively). RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between ETT mean of the different positions. The ETT means were 5.2 ± 1.1 s, 6.1 ± 1.5 s, and 23.6 ± 9.2 s for 90º, 45º and 0º, respectively. Pearson correlation results were r = -0.716 and P 0.05 according the subject’s BMI. CONCLUSION: We demonstrated that using this biomagnetic technique, it is possible to measure the ETT and the effects of the anatomical position on the ETT. PMID:18837088

  19. 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%.

  20. Long-term transit timing monitoring and homogenous study of WASP-32

    International Nuclear Information System (INIS)

    Sun Lei-Lei; Gu Sheng-Hong; Wang Xiao-Bin; Cao Dong-Tao; Wang Yi-Bo; Xiang Yue; Cameron Andrew Collier; Hui Ho-Keung; Kwok Chi-Tai; Yeung Bill; Leung Kam-Cheung

    2015-01-01

    We report new photometric observations of the transiting exoplanetary system WASP-32 made by using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China from 2010 to 2012. Following our usual procedure, the observed data are corrected for systematic errors according to the coarse decorrelation and SYSREM algorithms so as to enhance the signal of the transit events. Combined with radial velocity data presented in the literature, our newly observed data and earlier photometric data in the literature are simultaneously analyzed to derive the physical parameters describing the system by employing the Markov chain Monte Carlo technique. The derived parameters are consistent with the result published in the original paper about WASP-32b, but the uncertainties of the new parameters are smaller than those in the original paper. Moreover, our modeling result supports a circular orbit for WASP-32b. Through the analysis of all available mid-transit times, we have refined the orbital period of WASP-32b; no evident transit timing variation is found in these transit events. (research papers)

  1. 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

  2. Transit timing variations for planets co-orbiting in the horseshoe regime

    Energy Technology Data Exchange (ETDEWEB)

    Vokrouhlický, David [Institute of Astronomy, Charles University, V Holešovičkách 2, CZ-18000 Prague 8 (Czech Republic); Nesvorný, David, E-mail: vokrouhl@cesnet.cz, E-mail: davidn@boulder.swri.edu [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

    2014-08-10

    Although not yet detected, pairs of exoplanets in 1:1 mean motion resonance probably exist. Low eccentricity, near-planar orbits, which in the comoving frame follow horseshoe trajectories, are one of the possible stable configurations. Here we study transit timing variations (TTVs) produced by mutual gravitational interaction of planets in this orbital architecture, with the goal to develop methods that can be used to recognize this case in observational data. In particular, we use a semi-analytic model to derive parametric constraints that should facilitate data analysis. We show that characteristic traits of the TTVs can directly constrain the (1) ratio of planetary masses and (2) their total mass (divided by that of the central star) as a function of the minimum angular separation as seen from the star. In an ideal case, when transits of both planets are observed and well characterized, the minimum angular separation can also be inferred from the data. As a result, parameters derived from the observed transit timing series alone can directly provide both planetary masses scaled to the central star mass.

  3. 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.

  4. Sensitivity of Catchment Transit Times to Rainfall Variability Under Present and Future Climates

    Science.gov (United States)

    Wilusz, Daniel C.; Harman, Ciaran J.; Ball, William P.

    2017-12-01

    Hydrologists have a relatively good understanding of how rainfall variability shapes the catchment hydrograph, a reflection of the celerity of hydraulic head propagation. Much less is known about the influence of rainfall variability on catchment transit times, a reflection of water velocities that control solute transport. This work uses catchment-scale lumped parameter models to decompose the relationship between rainfall variability and an important metric of transit times, the time-varying fraction of young water (environmental tracer data from neighboring headwater catchments in Plynlimon, Wales from 1999 to 2008. At both sites, the mean annual FYW increased more than 13 percentage points from the driest to the wettest year. Yearly mean rainfall explained most between-year variation, but certain signatures of rainfall pattern were also associated with higher FYW including: more clustered storms, more negatively skewed storms, and higher covariance between daily rainfall and discharge. We show that these signatures are symptomatic of an "inverse storage effect" that may be common among watersheds. Looking to the future, changes in rainfall due to projected climate change caused an up to 19 percentage point increase in simulated mean winter FYW and similarly large decreases in the mean summer FYW. Thus, climate change could seasonally alter the ages of water in streams at these sites, with concomitant impacts on water quality.

  5. Transit timing variations for planets co-orbiting in the horseshoe regime

    International Nuclear Information System (INIS)

    Vokrouhlický, David; Nesvorný, David

    2014-01-01

    Although not yet detected, pairs of exoplanets in 1:1 mean motion resonance probably exist. Low eccentricity, near-planar orbits, which in the comoving frame follow horseshoe trajectories, are one of the possible stable configurations. Here we study transit timing variations (TTVs) produced by mutual gravitational interaction of planets in this orbital architecture, with the goal to develop methods that can be used to recognize this case in observational data. In particular, we use a semi-analytic model to derive parametric constraints that should facilitate data analysis. We show that characteristic traits of the TTVs can directly constrain the (1) ratio of planetary masses and (2) their total mass (divided by that of the central star) as a function of the minimum angular separation as seen from the star. In an ideal case, when transits of both planets are observed and well characterized, the minimum angular separation can also be inferred from the data. As a result, parameters derived from the observed transit timing series alone can directly provide both planetary masses scaled to the central star mass.

  6. An Inflection Point Method for the Determination of Pulmonary Transit Time From Contrast Echocardiography.

    Science.gov (United States)

    Boronyak, Steven M; Monahan, Ken; Brittain, Evan L; Merryman, W David

    2015-07-01

    Indicator-dilution curves (IDCs) for the estimation of pulmonary transit times (PTTs) can be generated noninvasively using contrast echocardiography. Currently, these IDCs are analyzed by manual inspection, which is not feasible in a clinical setting, or fit to a statistical model to derive parameters of interest. However, IDCs generated from patients are frequently subject to significant low-frequency noise and recirculation artifacts that obscure the first-pass signal and render model fitting impractical or inaccurate. Thus, the objective of this paper was to develop alternative computational methods to determine PTT using noisy clinical data in which the signal decay is not adequately visible. We report on a method that uses a model fit to the rise portion of the IDCs to determine the signal inflection point. Additionally, a signal truncation algorithm was developed that enables automated analysis of the IDCs. We compare PTTs derived from our inflection point method to those obtained by manual inspection in 25 patients (R(2) = 0.86) and to those obtained by mean transit time calculation following fitting to a local density random walk model (R(2) = 0.80) in a subset of this cohort. Combined with a signal truncation algorithm, the inflection point method provides robust, automated determination of PTT from noisy IDCs containing recirculation artifacts. The inflection point method addresses the need for computational analysis of IDCs obtained from contrast echocardiograms that are not amenable to first-pass model fitting.

  7. 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.

  8. Arduino based radiation survey meter

    International Nuclear Information System (INIS)

    Rahman, Nur Aira Abd; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee; Muzakkir, Amir

    2016-01-01

    This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr −1 ). Conversion factor (CF) value for conversion of CPM to μSvhr −1 determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr

  9. Arduino based radiation survey meter

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Nur Aira Abd, E-mail: nur-aira@nm.gov.my; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee [Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Muzakkir, Amir [Sinaran Utama Teknologi Sdn Bhd, 43650, Bandar Baru Bangi, Selangor (Malaysia)

    2016-01-22

    This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr{sup −1}). Conversion factor (CF) value for conversion of CPM to μSvhr{sup −1} determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr.

  10. Intelligent Flow Control Valve

    Science.gov (United States)

    Kelley, Anthony R (Inventor)

    2015-01-01

    The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely.

  11. 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.

  12. 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.

  13. 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.

  14. Arrival metering fuel consumption analysis

    Science.gov (United States)

    2011-01-01

    Arrival metering is a method of time-based traffic management that is used by the Federal Aviation Administration to plan and manage streams of arrival traffic during periods of : high demand at busy airports. The Traffic Management Advisor is an aut...

  15. Streamlining Smart Meter Data Analytics

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Nielsen, Per Sieverts

    2015-01-01

    of the so-called big data possible. This can improve energy management, e.g., help utilities improve the management of energy and services, and help customers save money. As this regard, the paper focuses on building an innovative software solution to streamline smart meter data analytic, aiming at dealing...

  16. 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

    2015-09-01

    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 the effects of the intervention on the latency to on-task behavior of 4 students in 2 classrooms. Data also were collected on students' on-task behavior during activities and teachers' use of prompts and praise statements. Implementation of the intervention substantially decreased students' latencies to on-task behavior and increased on-task behavior overall. Further, the 2 teachers used fewer prompts to cue students to transition and stay on task and provided more praise during intervention phases. We discuss how automating classroom interventions may affect student and teacher behavior as well as how it may increase procedural fidelity. © Society for the Experimental Analysis of Behavior.

  17. 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.

  18. 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

    The transit timing variation technique (TTV) has been widely used to detect and characterize multiple planetary systems. Due to the observational biases imposed mainly by the photometric conditions and instrumentation and the high signal-to-noise required to produce primary transit observations...... the observing time at hand carrying out such follow-ups, or if the use of medium-to-low quality transit light curves, combined with current standard techniques of data analysis, could be playing a main role against exoplanetary search via TTVs. The purpose of this work is to investigate to what extent ground......-based observations treated with current modelling techniques are reliable to detect and characterize additional planets in already known planetary systems. To meet this goal, we simulated typical primary transit observations of a hot Jupiter mimicing an existing system, Qatar-1. To resemble ground-based observations...

  19. Relationship between gastrointestinal transit time and anesthetic fasting protocols in the captive chimpanzee, Pan troglodytes.

    Science.gov (United States)

    Ardente, A; Chinnadurai, S; De Voe, R; Stringer, E; Webb, T; Ireland, J; Saker, K

    2011-06-01

    Lengthy social separation and prolonged fasting time contribute to increased risks associated with anesthesia in captive primates. This study is an initial attempt to identify a safe pre-anesthetic fasting procedure by identifying gastric emptying time (GET) and gastrointestinal transit time (GTT) of captive chimpanzees, Pan troglodytes. Seven adult chimpanzees at the North Carolina Zoo immobilized for annual physical examinations were fed barium-impregnated polyethylene spheres to measure GET. Eleven animals were individually fed a color dye marker and fecal passage was observed to determine GTT. Gastric emptying time (GET) was approximated to be >3 hours but fasting time of 3 hours would allow for complete gastric emptying and could potentially replace the current overnight fast (≥16 hour) to help minimize complications associated with pre-anesthetic fasting in captive primates. © 2011 John Wiley & Sons A/S.

  20. Smart metering. Conformance tests for electricity meters; Smart Metering. Konformitaetstests an Stromzaehlern

    Energy Technology Data Exchange (ETDEWEB)

    Bormann, Matthias; Pongratz, Siegfried [VDE Pruef- und Zertifizierungsinstitut, Offenbach (Germany)

    2012-07-01

    Introduction of communication technologies into today's energy network enables the interworking between the domains of smart metering, smart grid, smart home and e-mobility as well as the creation and provisioning of new innovative services such as efficient load adjustment. Due to this convergence the new energy networks are becoming increasingly complex. Ensuring the interworking between all network elements (e.g. electricity meters, gateways) in these smart energy networks is of utmost importance. To this end conformance and interoperability tests have to be defined to ensure that services work as expected. (orig.)

  1. The importance of water transit time and mineral dissolution kinetics for the flux of weathering products

    Science.gov (United States)

    Erlandsson, Martin; Bishop, Kevin; Köhler, Stephan; Amvrosiadi, Nino

    2016-04-01

    Soil mineral weathering is one of the major sources of base cations (BC), which play a dual role for a forest ecosystem; they function both as plant nutrients, and for buffering against acidification of catchment runoff. On a long-term basis, the soil weathering rates will determine the highest sustainable forest productivity without causing acidification. It is believed that the hydrologic residence time play a key role in determining weathering rates on a landscape scale. In this study, we investigate the significance of the water transit residence time (WTT) distribution for the transport of base cations to catchment runoff. By modelling hillslope flowpaths with different transit times, using the geochemical computing code PHREEQC, we demonstrate how in-stream dynamics as exemplified by elemental ratios can be explained by mineral dissolution kinetics and equilibria. Specifically, we hypothesize that equilibrium of plagioclase regulates the delivery of base cations and silica to catchment runoff. These patters can be seen in field data from 10 years of sampling from a nested-catchment, where the Na+/BC and the Si/BC-ratios vary systematically with WTT on both a temporal and a spatial scale. This behavior has implications for the total transport of products from mineral dissolution to catchment runoff. As the water entering the stream is a mixture of water with different transit times, the composition of stream water will not only be dependent on the average WTT, but also on the shape of the WTT distribution. For the base cations associated with minerals that becomes supersaturated or with precipitating secondary phases within the range of WTT, i.e. Na+ and K+, the tails of "old water" of the WRT-distribution will not contribute to any extra transport of these elements. Finally, we use the derived relationships to estimate the transport of weathering products from a forested hillslope, given the modelled WRT distribution.

  2. Transit-time and age distributions for nonlinear time-dependent compartmental systems.

    Science.gov (United States)

    Metzler, Holger; Müller, Markus; Sierra, Carlos A

    2018-02-06

    Many processes in nature are modeled using compartmental systems (reservoir/pool/box systems). Usually, they are expressed as a set of first-order differential equations describing the transfer of matter across a network of compartments. The concepts of age of matter in compartments and the time required for particles to transit the system are important diagnostics of these models with applications to a wide range of scientific questions. Until now, explicit formulas for transit-time and age distributions of nonlinear time-dependent compartmental systems were not available. We compute densities for these types of systems under the assumption of well-mixed compartments. Assuming that a solution of the nonlinear system is available at least numerically, we show how to construct a linear time-dependent system with the same solution trajectory. We demonstrate how to exploit this solution to compute transit-time and age distributions in dependence on given start values and initial age distributions. Furthermore, we derive equations for the time evolution of quantiles and moments of the age distributions. Our results generalize available density formulas for the linear time-independent case and mean-age formulas for the linear time-dependent case. As an example, we apply our formulas to a nonlinear and a linear version of a simple global carbon cycle model driven by a time-dependent input signal which represents fossil fuel additions. We derive time-dependent age distributions for all compartments and calculate the time it takes to remove fossil carbon in a business-as-usual scenario.

  3. The scintigraphic determination of small intestinal transit time in patients with irritable bowel syndrome

    International Nuclear Information System (INIS)

    Marano, A.R.; Caride, V.J.; Shah, R.V.; Prokop, E.K.; Troncale, F.J.; McCallum, R.W.

    1984-01-01

    Diffuse disturbance in gastrointestinal motility may be present in patients with irritable bowel syndrome (IBS). To further investigate small intestinal motility in IBS patients small intestinal transit time (SITT) was determined and related to the symptom status. 11 female patients with IBS (mean age 29 years) were divided into those whose predominate symptom was diarrhea (N=6), and those with only constipation (N=5). All subjects ingested an isosmotic solution of lactulose (10 gm in 150cc of water) labeled with 99m-Tc-DTPA (Sn). The patient was studied supine under a 25 inch gamma camera with data collected at 1 frame per minute for 180 minutes or until activity appeared in the ascending colon. Regions of interest were selected over the cecum and ascending colon. The time of first appearance of radioactivity in the region of the cecum was taken as the small intestinal transit time. SITT in the 5 normal females was 98.7 +- 13 min (mean +- SEM). SITT in the IBS patients with diarrhea, 67.3 +- 7 min was significantly faster (p< 0.08). SITT in the constipated IBS patients, 126 +- 12 min, was slower than normals and significantly different from diarrhea patients (p< 0.001). These studies show that IBS patients with diarrhea have significantly faster SITT than normals while constipated IBS patients have significantly slower SITT than the diarrhea subgroup. Further, this study emphasizes the need to study the various symptomatic subgroups of IBs patients independently and indicates a possible role for abnormal SITT in the pathogenesis of IBS

  4. The scintigraphic determination of small intestinal transit time in patients with irritable bowel syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Marano, A.R.; Caride, V.J.; Shah, R.V.; Prokop, E.K.; Troncale, F.J.; McCallum, R.W.

    1984-01-01

    Diffuse disturbance in gastrointestinal motility may be present in patients with irritable bowel syndrome (IBS). To further investigate small intestinal motility in IBS patients small intestinal transit time (SITT) was determined and related to the symptom status. 11 female patients with IBS (mean age 29 years) were divided into those whose predominate symptom was diarrhea (N=6), and those with only constipation (N=5). All subjects ingested an isosmotic solution of lactulose (10 gm in 150cc of water) labeled with 99m-Tc-DTPA (Sn). The patient was studied supine under a 25 inch gamma camera with data collected at 1 frame per minute for 180 minutes or until activity appeared in the ascending colon. Regions of interest were selected over the cecum and ascending colon. The time of first appearance of radioactivity in the region of the cecum was taken as the small intestinal transit time. SITT in the 5 normal females was 98.7 +- 13 min (mean +- SEM). SITT in the IBS patients with diarrhea, 67.3 +- 7 min was significantly faster (p< 0.08). SITT in the constipated IBS patients, 126 +- 12 min, was slower than normals and significantly different from diarrhea patients (p< 0.001). These studies show that IBS patients with diarrhea have significantly faster SITT than normals while constipated IBS patients have significantly slower SITT than the diarrhea subgroup. Further, this study emphasizes the need to study the various symptomatic subgroups of IBs patients independently and indicates a possible role for abnormal SITT in the pathogenesis of IBS.

  5. Electricity as (Big Data: Metering, spatiotemporal granularity and value

    Directory of Open Access Journals (Sweden)

    Mette Kragh-Furbo

    2018-02-01

    Full Text Available Electricity is hidden within wires and networks only revealing its quantity and flow when metered. The making of its properties into data is therefore particularly important to the relations that are formed around electricity as a produced and managed phenomenon. We propose approaching all metering as a situated activity, a form of quantification work in which data is made and becomes mobile in particular spatial and temporal terms, enabling its entry into data infrastructures and schemes of evaluation and value production. We interrogate the transition from the pre-digital into the making of bigger, more spatiotemporally granular electricity data, through focusing on those actors selling and materialising new metering technologies, data infrastructures and services for larger businesses and public sector organisations in the UK. We examine the claims of truth and visibility that accompany these shifts and their enrolment into management techniques that serve to more precisely apportion responsibility for, and evaluate the status of, particular patterns and instances of electricity use. We argue that whilst through becoming Big Data electricity flow is now able to be known and given identity in significantly new terms, enabling new relations to be formed with the many heterogeneous entities implicated in making and managing energy demand, it is necessary to sustain some ambivalence as to the performative consequences that follow for energy governance. We consider the wider application of our conceptualisation of metering, reflecting on comparisons with the introduction of new metering systems in domestic settings and as part of other infrastructural networks.

  6. The association between neurological deficit in acute ischemic stroke and mean transit time. Comparison of four different perfusion MRI algorithms

    International Nuclear Information System (INIS)

    Schellinger, Peter D.; Latour, Lawrence L.; Chalela, Julio A.; Warach, Steven; Wu, Chen-Sen

    2006-01-01

    The purpose of our study was to identify the perfusion MRI (pMRI) algorithm which yields a volume of hypoperfused tissue that best correlates with the acute clinical deficit as quantified by the NIH Stroke Scale (NIHSS) and therefore reflects critically hypoperfused tissue. A group of 20 patients with a first acute stroke and stroke MRI within 24 h of symptom onset were retrospectively analyzed. Perfusion maps were derived using four different algorithms to estimate relative mean transit time (rMTT): (1) cerebral blood flow (CBF) arterial input function (AIF)/singular voxel decomposition (SVD); (2) area peak; (3) time to peak (TTP); and (4) first moment method. Lesion volumes based on five different MTT thresholds relative to contralateral brain were compared with each other and correlated with NIHSS score. The first moment method had the highest correlation with NIHSS (r=0.79, P<0.001) followed by the AIF/SVD method, both of which did not differ significantly from each other with regard to lesion volumes. TTP and area peak derived both volumes, which correlated poorly or only moderately with NIHSS scores. Data from our pilot study suggest that the first moment and the AIF/SVD method have advantages over the other algorithms in identifying the pMRI lesion volume that best reflects clinical severity. At present there seems to be no need for extensive postprocessing and arbitrarily defined delay thresholds in pMRI as the simple qualitative approach with a first moment algorithm is equally accurate. Larger sample sizes which allow comparison between imaging and clinical outcomes are needed to refine the choice of best perfusion parameter in pMRI. (orig.)

  7. Errors analysis in the evaluation of particle concentration by PDA on a turbulent two-phase jet: application for cross section and transit time methods

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Esteban; Garcia, Juan A.; Garcia, Ignacio; Aisa, Luis A. [University of Zaragoza, Area de Mecanica de Fluidos, Centro Politecnico Superior, Zaragoza (Spain)

    2009-09-15

    Phase-Doppler anemometry (PDA) is a powerful tool for two-phase flow measurements and testing. Particle concentration and mass flux can also be evaluated using the raw particle data supplied by this technique. The calculation starts from each particle velocity, diameter, transit time data, and the total measurement time. There are two main evaluation strategies. The first one uses the probe volume effective cross section, and it is usually simplified assuming that particles follow quasi one-directional trajectories. In the text, it will be called the cross section method. The second one includes a set of methods which will be denoted as ''Generalized Integral Methods'' (GIM). Concentration algorithms such as the transit time method (TTM) and the integral volume method (IVM) are particular cases of the GIM. In any case, a previous calibration of the measurement volume geometry is necessary to apply the referred concentration evaluation methods. In this study, concentrations and mass fluxes both evaluated by the cross-section method and the TTM are compared. Experimental data are obtained from a particle-laden jet generated by a convergent nozzle. Errors due to trajectory dispersion, burst splitting, and multi-particle signals are discussed. (orig.)

  8. Using tracer-derived groundwater transit times to assess storage within a high-elevation watershed of the upper Colorado River Basin, USA

    Science.gov (United States)

    Georgek, Jennifer L.; Kip Solomon, D.; Heilweil, Victor M.; Miller, Matthew P.

    2018-03-01

    Previous watershed assessments have relied on annual baseflow to evaluate the groundwater contribution to streams. To quantify the volume of groundwater in storage, additional information such as groundwater mean transit time (MTT) is needed. This study determined the groundwater MTT in the West Fork Duchesne watershed in Utah (USA) with lumped-parameter modeling of environmental tracers (SF6, CFCs, and 3H/3He) from 21 springs. Approximately 30% of the springs exhibited an exponential transit time distribution (TTD); the remaining 70% were best characterized by a piston-flow TTD. The flow-weighted groundwater MTT for the West Fork watershed is about 40 years with approximately 20 years in the unsaturated zone. A cumulative distribution of these ages revealed that most of the groundwater is between 30 and 50 years old, suggesting that declining recharge associated with 5-10-year droughts is less likely to have a profound effect on this watershed compared with systems with shorter MTTs. The estimated annual baseflow of West Fork stream flow based on chemical hydrograph separation is 1.7 × 107 m3/year, a proxy for groundwater discharge. Using both MTT and groundwater discharge, the volume of mobile groundwater stored in the watershed was calculated to be 6.5 × 108 m3, or 20 m thickness of active groundwater storage and recharge of 0.09 m/year (assuming porosity = 15%). Future watershed-scale assessments should evaluate groundwater MTT, in addition to annual baseflow, to quantify groundwater storage and more accurately assess watershed susceptibility to drought, groundwater extraction, and land-use change.

  9. Estimation of Catchment Transit Time in Fuji River Basin by using an improved Tank model

    Science.gov (United States)

    Wenchao, M.; Yamanaka, T.; Wakiyama, Y.; Wang, P.

    2013-12-01

    As an important parameter that reflects the characteristics of catchments, the catchment transit time (CTT) has been given much more widely attentions especially in recent years. The CTT is defined as the time water spends travelling through a catchment to the stream network [1], and it describes how catchments retain and release water and solutes and thus control geochemical and biogeochemical cycling and contamination persistence [2]. The objectives of the present study are to develop a new approach for estimating CTT without prior information on such TTD functions and to apply it to the Fuji River basin in the Central Japan Alps Region. In this study, an improved Tank model was used to compute mean CTT and TTD functions simultaneously. It involved water fluxes and isotope mass balance. Water storage capacity in the catchment, which strongly affects CTT, is reflected in isotope mass balance more sensitively than in water fluxes. A model calibrated with observed discharge and isotope data is used for virtual age tracer computation to estimate CTT. This model does not only consider the hydrological data and physical process of the research area but also reflects the actual TTD with considering the geological condition, land use and the other catchment-hydrological conditions. For the calibration of the model, we used river discharge record obtained by the Ministry of Land, Infrastructure and Transportation, and are collecting isotope data of precipitation and river waters monthly or semi-weekly. Three sub-catchments (SC1~SC3) in the Fuji River basin was selected to test the model with five layers: the surface layer, upper-soil layer, lower-soil layer, groundwater aquifer layer and bedrock layer (Layer 1- Layer 5). The evaluation of the model output was assessed using Nash-Sutcliffe efficiency (NSE), root mean square error-observations standard deviation ratio (RSR), and percent bias (PBIAS). Using long time-series of discharge records for calibration, the simulated

  10. Federal Building Metering Guidance (per 42 U.S.C. 8253(e), Metering of Energy Use)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-11-01

    Guidance defines which federal buildings are appropriate to meter, provides metering prioritization recommendations for agencies with limited resources, and discusses the requirement for agencies to submit metering implementation plans to the U.S. Department of Energy.

  11. Densities and eccentricities of 139 Kepler planets from transit time variations

    Energy Technology Data Exchange (ETDEWEB)

    Hadden, Sam; Lithwick, Yoram [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2014-05-20

    We extract densities and eccentricities of 139 sub-Jovian planets by analyzing transit time variations (TTVs) obtained by the Kepler mission through Quarter 12. We partially circumvent the degeneracies that plague TTV inversion with the help of an analytical formula for the TTV. From the observed TTV phases, we find that most of these planets have eccentricities of the order of a few percent. More precisely, the rms eccentricity is 0.018{sub −0.004}{sup +0.005}, and planets smaller than 2.5 R {sub ⊕} are around twice as eccentric as those bigger than 2.5 R {sub ⊕}. We also find a best-fit density-radius relationship ρ ≈ 3 g cm{sup –3} × (R/3 R {sub ⊕}){sup –2.3} for the 56 planets that likely have small eccentricity and hence small statistical correction to their masses. Many planets larger than 2.5 R {sub ⊕} are less dense than water, implying that their radii are largely set by a massive hydrogen atmosphere.

  12. [PULSE WAVE TRANSIT TIME - ONE MORE ATTEMPT OF NON-INVASIVE CARDIAC OUTPUT MEASUREMENT.

    Science.gov (United States)

    Akselrod, B A; Tolstova, L A; Pshenichniy, T A; Fedulova, S V

    2017-09-01

    Estimated continuous cardiac output (esCCOTM) based on pulse wave transit time is one of alternative non-invasive CO measurement techniques. Randomized study included 23 scheduled patients operated upon due to cardiovascular diseases. Cardiac index (CI) was measured Comparative analyses of esCCO and others CO measurement methods used intraoperative was carried out. In the first group (n = 9) esCCO was compared with transpulmonary thermodilution (PiCCO-plus); in the second group (n = 8) - with pulmonary artery thermodilution; in the third group (n = 6) - with transoesophageal echocardiography (velocity-time integral). In the 1st group direct correlation was found (r = 0,773, p measurements were out of reference interval (more than ? 15%). Blend- Altman method showed the dispersion of results in all groups. 1. Estimated continuous cardiac output measurement technique based on PWTT has a direct correla- tion with prepulmonary thermodilution and transoesophageal echocardiography, medium and high power respectively. 2. esCCO has significant differences with the referential techniques during general anesthesia in cardiac surgery pa- tients. 3. Calibration based on invasive blood pressure and outside cardiac output measurement does not increase the accuracy of measurements. 4. esCCO has a negative diagnostic value and cannot be recommendedfor the cardiac out- put evaluation during cardiac surgery. 5. This method can be useful for analyze general effectiveness of perioperative hemodynamics.

  13. Relationship between faecal character and intestinal transit time in normal dogs and diet-sensitive dogs.

    Science.gov (United States)

    Rolfe, V E; Adams, C A; Butterwick, R F; Batt, R M

    2002-07-01

    The relationship between stool character and whole gut transit time (WGTT), which is the average time for the passage of material through the lumen of the alimentary tract from ingestion to defecation, was studied in eight control dogs and 12 dogs with non-specific dietary sensitivity. Dogs were fed four diets in a cross-over design, and faecal quality was assessed daily and WGTT determined using plastic pellets. Faecal quality was unaffected by diet in the control dogs. Dogs with dietary sensitivity produced looser faeces compared with the control dogs, and this was significant for two of the diets. There was no significant effect of diet on mean WGTT within or between groups. Minimum WGTT, which was the interval to the first appearance of markers in faeces, was shorter in sensitive dogs compared with controls, and this was significant for two of the four diets. There were significant, inverse relationships between minimum WGTT and both mean faeces score and percentage unacceptable defecations. These data suggest that rapid transit of certain dietary components may impact negatively on stool quality and contribute to loose faeces in dogs with non-specific dietary sensitivity.

  14. 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.

  15. Comparison of colonic transit time findings between spastic pelvic floor syndrome and normal on defecogram

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Kwon; Choi, Sang Hee; Chung, Il Gyu; Lim, Hyo Keun; Choo, Sung Wook; Rhee, Poong Lyul [Samsung Medical Center, Seoul (Korea, Republic of)

    1998-05-01

    The purpose of this study is to evaluate colonic transit time (CTT) in patients with spastic pelvic floor syndrome (SPFS) diagnosed by defecography and compare findings with those of patients with normal defecography. Over a recent 15-month period, 140 patients underwent both defecography and CTT test because of chronic idiopathic constipation. Of these, 54 with SPFS diagnosed by defecography and 49 controls with normal defecography were included in our study. CTT test involved the radiopaque marker method. Subjects ingested 24 markers at 9:00 Am on three consecutive days and a plain film of the abdomen was obtained on day 4. We calculated total and segmental CTT test findings in the two groups. Delayed total CTT was found in 35% of patients (19/54) with SPFS. Segmental CTT in the right, left and rectosigmoid colon was delayed in 31 % of patients (15/49) with SPFS. Segmental CTT in the right, left and rectosigmoid colon was delayed in 19 % (10/54), 44 % (24/54), and 31 % of cases (17/54), respectively. Total CTT was delayed in 31 % of patients (15/49) with normal defecography. In this group, segmental CTT in the left colon was delayed in 39 % of cases. There was no significant difference in CTT findings between the SPFS and normal groups on defecogram. (author). 18 refs., 2 tabs., 5 figs.

  16. 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.

  17. Comparison of colonic transit time findings between spastic pelvic floor syndrome and normal on defecogram

    International Nuclear Information System (INIS)

    Kim, Seung Kwon; Choi, Sang Hee; Chung, Il Gyu; Lim, Hyo Keun; Choo, Sung Wook; Rhee, Poong Lyul

    1998-01-01

    The purpose of this study is to evaluate colonic transit time (CTT) in patients with spastic pelvic floor syndrome (SPFS) diagnosed by defecography and compare findings with those of patients with normal defecography. Over a recent 15-month period, 140 patients underwent both defecography and CTT test because of chronic idiopathic constipation. Of these, 54 with SPFS diagnosed by defecography and 49 controls with normal defecography were included in our study. CTT test involved the radiopaque marker method. Subjects ingested 24 markers at 9:00 Am on three consecutive days and a plain film of the abdomen was obtained on day 4. We calculated total and segmental CTT test findings in the two groups. Delayed total CTT was found in 35% of patients (19/54) with SPFS. Segmental CTT in the right, left and rectosigmoid colon was delayed in 31 % of patients (15/49) with SPFS. Segmental CTT in the right, left and rectosigmoid colon was delayed in 19 % (10/54), 44 % (24/54), and 31 % of cases (17/54), respectively. Total CTT was delayed in 31 % of patients (15/49) with normal defecography. In this group, segmental CTT in the left colon was delayed in 39 % of cases. There was no significant difference in CTT findings between the SPFS and normal groups on defecogram. (author). 18 refs., 2 tabs., 5 figs

  18. Eight planets in four multi-planet systems via transit timing variations in 1350 days

    International Nuclear Information System (INIS)

    Yang, Ming; Liu, Hui-Gen; Zhang, Hui; Yang, Jia-Yi; Zhou, Ji-Lin

    2013-01-01

    Analysis of the transit timing variations (TTVs) of candidate pairs near mean-motion resonances (MMRs) is an effective method to confirm planets. Hitherto, 68 planets in 34 multi-planet systems have been confirmed via TTVs. We analyze the TTVs of all candidates from the most recent Kepler data with a time span of upto about 1350 days (Q0-Q15). The anti-correlations of TTV signals and the mass upper limits of candidate pairs in the same system are calculated using an improved method suitable for long-period TTVs. If the false alarm probability of a candidate pair is less than 10 –3 and the mass upper limit for each candidate is less than 13 M J , we confirm them as planets in the same system. Finally, eight planets in four multi-planet systems are confirmed via analysis of their TTVs. All of the four planet pairs are near first-order MMRs, including KOI-2672 near 2:1 MMR and KOI-1236, KOI-1563, and KOI-2038 near 3:2 MMR. Four planets have relatively long orbital periods (>35 days). KOI-2672.01 has an orbital period of 88.51658 days and a fit mass of 17 M ⊕ . To date, it is the longest-period planet confirmed near a first-order MMR via TTVs.

  19. 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.

  20. Decreased colonic transit time after transcutaneous interferential electrical stimulation in children with slow transit constipation.

    Science.gov (United States)

    Clarke, Melanie C C; Chase, Janet W; Gibb, Susie; Robertson, Val J; Catto-Smith, Anthony; Hutson, John M; Southwell, Bridget R

    2009-02-01

    Idiopathic slow transit constipation (STC) describes a clinical syndrome characterised by intractable constipation. It is diagnosed by demonstrating delayed colonic transit on nuclear transit studies (NTS). A possible new treatment is interferential therapy (IFT), which is a form of electrical stimulation that involves the transcutaneous application of electrical current. This study aimed to ascertain the effect of IFT on colonic transit time. Children with STC diagnosed by NTS were randomised to receive either 12 real or placebo IFT sessions for a 4-week period. After a 2-month break, they all received 12 real IFT sessions-again for a 4-week period. A NTS was repeated 6 to 8 weeks after cessation of each treatment period where able. Geometric centres (GCs) of activity were calculated for all studies at 6, 24, 30, and 48 hours. Pretreatment and posttreatment GCs were compared by statistical parametric analysis (paired t test). Thirty-one pretreatment, 22 postreal IFT, and 8 postplacebo IFT studies were identified in 26 children (mean age, 12.7 years; 16 male). Colonic transit was significantly faster in children given real treatment when compared to their pretreatment NTS at 24 (mean CG, 2.39 vs 3.04; P interferential therapy can significantly speed up colonic transit in children with slow transit constipation.

  1. 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

  2. Flow

    DEFF Research Database (Denmark)

    Knoop, Hans Henrik

    2006-01-01

    FLOW. Orden i hovedet på den fede måde Oplevelsesmæssigt er flow-tilstanden kendetegnet ved at man er fuldstændig involveret, fokuseret og koncentreret; at man oplever stor indre klarhed ved at vide hvad der skal gøres, og i hvilket omfang det lykkes; at man ved at det er muligt at løse opgaven...

  3. Net metering in British Columbia : white paper

    International Nuclear Information System (INIS)

    Berry, T.

    2003-01-01

    Net metering was described as being the reverse registration of an electricity customer's revenue meter when interconnected with a utility's grid. It is a provincial policy designed to encourage small-distributed renewable power generation such as micro-hydro, solar energy, fuel cells, and larger-scale wind energy. It was noted that interconnection standards for small generation is an important issue that must be addressed. The British Columbia Utilities Commission has asked BC Hydro to prepare a report on the merits of net metering in order to support consultations on a potential net metering tariff application by the utility. This report provides information on net metering with reference to experience in other jurisdictions with net metering, and the possible costs and benefits associated with net metering from both a utility and consumer perspective. Some of the barriers and policy considerations for successful implementation of net metering were also discussed. refs., tabs., figs

  4. Calibration of dose meters used in radiotherapy

    International Nuclear Information System (INIS)

    1979-01-01

    This manual is a practical guide, not a comprehensive textbook, to the instrumentation and procedures necessary to calibrate a radiation dose meter used in clinical practice against a secondary standard dose meter

  5. 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.

  6. Esophageal transit time in patients with chagasic megaesophagus: Lack of linear correlation between dysphagia and grade of dilatation.

    Science.gov (United States)

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

    2018-03-01

    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.

  7. Capacitive level meter for liquid hydrogen

    OpenAIRE

    Matsumoto, Koichi; Sobue, Masamitsu; Asamoto, Kai; Nishimura, Yuta; Abe, Satoshi; Numazawa, Takenori

    2011-01-01

    A capacitive level meter working at low temperatures was made to use in magnetic refrigerator for hydrogen liquefaction. The liquid level was measured from the capacitance between parallel electrodes immersed in the liquid. The meter was tested for liquid nitrogen, hydrogen, and helium. The operation was successful using an AC capacitance bridge. The estimated sensitivity of the meter is better than 0.2 mm for liquid hydrogen. The meter also worked with pressurized hydrogen. © 2010.

  8. Scanray radiation meter type 751

    International Nuclear Information System (INIS)

    Burgess, P.H.; Iles, W.J.; White, D.F.

    1978-04-01

    This instrument is a portable, battery-powered exposure rate meter with a digital display covering the exposure rate range from 0.1 mR h -1 to 1.999 R h -1 . It is designed to measure X- and γ-radiation exposure rates over the energy range from 50 keV to 2.5 MeV. The radiation detector of the instrument is a GM tube. The report falls under the headings: general description, facilities and controls, radiation characteristics, electrical characteristics, environmental characteristics, construction, summary of performance, conclusions, manufacturer's comments. (U.K.)

  9. 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.

  10. 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.

  11. Probiotic supplementation decreases intestinal transit time: meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Miller, Larry E; Ouwehand, Arthur C

    2013-08-07

    To determine the efficacy of probiotic supplementation on intestinal transit time (ITT) and to identify factors that influence these outcomes. A systematic review of randomized controlled trials (RCTs) of probiotic supplementation that measured ITT in adults was conducted by searching MEDLINE and EMBASE using relevant key word combinations. Main search limits included RCTs of probiotic supplementation in healthy or constipated adults that measured ITT. Study quality was assessed using the Jadad scale. A random effects meta-analysis was performed with standardized mean difference (SMD) of ITT between probiotic and control groups as the primary outcome. Meta-regression and subgroup analyses were conducted to examine the impact of moderator variables on ITT SMD. A total of 11 clinical trials with 13 treatment effects representing 464 subjects were included in this analysis. Probiotic supplementation was associated with decreased ITT in relation to controls, with an SMD of 0.40 (95%CI: 0.20-0.59, P probiotics in meta-regression. Subgroup analyses demonstrated statistically greater reductions in ITT with probiotics in subjects with vs without constipation and in older vs younger subjects [both SMD: 0.59 (95%CI: 0.39-0.79) vs 0.17 (95%CI: -0.08-0.42), P = 0.01]. Medium to large treatment effects were identified with Bifidobacterium Lactis (B. lactis) HN019 (SMD: 0.72, 95%CI: 0.27-1.18, P products yielded small treatment effects. Overall, short-term probiotic supplementation decreases ITT with consistently greater treatment effects identified in constipated or older adults and with certain probiotic strains.

  12. TASTE. III. A homogeneous study of transit time variations in WASP-3b

    Science.gov (United States)

    Nascimbeni, V.; Cunial, A.; Murabito, S.; Sada, P. V.; Aparicio, A.; Piotto, G.; Bedin, L. R.; Milone, A. P.; Rosenberg, A.; Zurlo, A.; Borsato, L.; Damasso, M.; Granata, V.; Malavolta, L.

    2013-01-01

    The TASTE project is searching for low-mass planets with the transit timing variation (TTV) technique by gathering high-precision, short-cadence light curves for a selected sample of transiting exoplanets. It has been claimed that the "hot Jupiter" WASP-3b could be perturbed by a second planet. Presenting eleven new light curves (secured at the IAC80 and UDEM telescopes) and re-analyzing thirty-eight archival light curves in a homogeneous way, we show that new data do not confirm the previously claimed TTV signal. However, we bring evidence that measurements are not consistent with a constant orbital period, though no significant periodicity can be detected. Additional dynamical modeling and follow-up observations are planned to constrain the properties of the perturber or to put upper limits to it. We provide a refined ephemeris for WASP-3b and improved orbital/physical parameters. A contact eclipsing binary, serendipitously discovered among field stars, is reported here for the first time. This article is based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias (IAC) in the Spanish Observatorio del Teide.Tables 1 and 3 and Appendix A are available in electronic form at http://www.aanda.orgPhotometric data are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/549/A30

  13. 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 constipation-related subjective symptoms, including spontaneous bowel movement frequency, significantly improved compared with those before treatment. Serious adverse events did not occur. 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.

  14. Usefulness of colon transit time and defecography in patients with chronic constipation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyoung Seuk; Chung, Jae Joon; Kim, Myung Hyun; Park, Su Mi; Yang, Hee Chul [NHIC Ilsan Hospital, Ilsan (Korea, Republic of)

    2006-05-15

    We wanted to evaluate whether both the colonic transit time (CTT) and defecography are necessary for diagnosing constipated patients, and we also wanted to assess the defecographic findings of patients with outlet obstruction on CTT. Over the recent 3 years, 26 patients (21 women and 5 men, mean age: 59 years) underwent both CTT and defecography because of their chronic constipations or defecation difficulty. The mean interval between the 2 studies was 48 days. Colonoscopy, barium enema and manometry were performed in 22, 8 and all the patients, respectively. On CTT, 13 patients (50.0%) were normal and 13 patients (50.0%) were abnormal; the abnormal results were composed of outlet obstruction (n = 8, 30.8%), outlet obstruction and colon inertia (n = 2, 7.7%), colon inertia (n = 2, 7.7%), and outlet obstruction and hindgut dysfunction (n = 1, 3.8%). On defecography, 6 patients (23.1%) were normal and 20 patients (76.9%) were abnormal; the results were composed of rectocele (n = 8, 30.7%), rectocele and perineal descent syndrome (PDS; n = 4, 15.4%), PDS and rectal intussusception (n = 3, 11.5%), spastic pelvic floor syndrome (SPFS; n = 3, 11.5%), rectocele and SPFS (n = 1, 3.8%), and rectal intussusception (n = 1, 3.8%). Of the 11 patients with outlet obstruction on CTT, rectocele (n = 4, 36.4%), SPFS (n = 1, 9.1%), rectocele and PDS (n = 1, 9.1%), and PDS and rectal intussusception (n = 1, 9.1%) were demonstrated on defecography, except for the 4 normal cases. Both CTT and defecography were necessary for diagnosing the patients with chronic constipation in compensation, and 63.6% of the patients with pelvic outlet obstruction showed an abnormal pelvic defecation function.

  15. Usefulness of colon transit time and defecography in patients with chronic constipation

    International Nuclear Information System (INIS)

    Park, Kyoung Seuk; Chung, Jae Joon; Kim, Myung Hyun; Park, Su Mi; Yang, Hee Chul

    2006-01-01

    We wanted to evaluate whether both the colonic transit time (CTT) and defecography are necessary for diagnosing constipated patients, and we also wanted to assess the defecographic findings of patients with outlet obstruction on CTT. Over the recent 3 years, 26 patients (21 women and 5 men, mean age: 59 years) underwent both CTT and defecography because of their chronic constipations or defecation difficulty. The mean interval between the 2 studies was 48 days. Colonoscopy, barium enema and manometry were performed in 22, 8 and all the patients, respectively. On CTT, 13 patients (50.0%) were normal and 13 patients (50.0%) were abnormal; the abnormal results were composed of outlet obstruction (n = 8, 30.8%), outlet obstruction and colon inertia (n = 2, 7.7%), colon inertia (n = 2, 7.7%), and outlet obstruction and hindgut dysfunction (n = 1, 3.8%). On defecography, 6 patients (23.1%) were normal and 20 patients (76.9%) were abnormal; the results were composed of rectocele (n = 8, 30.7%), rectocele and perineal descent syndrome (PDS; n = 4, 15.4%), PDS and rectal intussusception (n = 3, 11.5%), spastic pelvic floor syndrome (SPFS; n = 3, 11.5%), rectocele and SPFS (n = 1, 3.8%), and rectal intussusception (n = 1, 3.8%). Of the 11 patients with outlet obstruction on CTT, rectocele (n = 4, 36.4%), SPFS (n = 1, 9.1%), rectocele and PDS (n = 1, 9.1%), and PDS and rectal intussusception (n = 1, 9.1%) were demonstrated on defecography, except for the 4 normal cases. Both CTT and defecography were necessary for diagnosing the patients with chronic constipation in compensation, and 63.6% of the patients with pelvic outlet obstruction showed an abnormal pelvic defecation function

  16. Predictable Patterns in Planetary Transit Timing Variations and Transit Duration Variations Due to Exomoons

    Science.gov (United States)

    Heller, Rene; Hippke, Michael; Placek, Ben; Angerhausen, Daniel; Agol, Eric

    2016-01-01

    We present new ways to identify single and multiple moons around extrasolar planets using planetary transit timing variations (TTVs) and transit duration variations (TDVs). For planets with one moon, measurements from successive transits exhibit a hitherto undescribed pattern in the TTV-TDV diagram, originating from the stroboscopic sampling of the planet's orbit around the planet-moon barycenter. This pattern is fully determined and analytically predictable after three consecutive transits. The more measurements become available, the more the TTV-TDV diagram approaches an ellipse. For planets with multiple moons in orbital mean motion resonance (MMR), like the Galilean moon system, the pattern is much more complex and addressed numerically in this report. Exomoons in MMR can also form closed, predictable TTV-TDV figures, as long as the drift of the moons' pericenters is suciently slow.We find that MMR exomoons produce loops in the TTV-TDV diagram and that the number of these loops is equal to the order of the MMR, or the largest integer in the MMR ratio.We use a Bayesian model and Monte Carlo simulations to test the discoverability of exomoons using TTV-TDV diagrams with current and near-future technology. In a blind test, two of us (BP, DA) successfully retrieved a large moon from simulated TTV-TDV by co-authors MH and RH, which resembled data from a known Kepler planet candidate. Single exomoons with a 10 percent moon-to-planet mass ratio, like to Pluto-Charon binary, can be detectable in the archival data of the Kepler primary mission. Multi-exomoon systems, however, require either larger telescopes or brighter target stars. Complementary detection methods invoking a moon's own photometric transit or its orbital sampling effect can be used for validation or falsification. A combination of TESS, CHEOPS, and PLATO data would offer a compelling opportunity for an exomoon discovery around a bright star.

  17. Smart meter status report from Toronto

    International Nuclear Information System (INIS)

    O'Brien, D.

    2006-01-01

    An update of Toronto Hydro's smart metering program was presented. Electricity demand is expected to keep increasing, and there is presently insufficient generation to match supply needs in Ontario. The smart metering program was introduced to aid in the Ontario government's energy conservation strategy, as well as to address peak supply problems that have led to power outages. It is expected that the smart metering program will reduce provincial peak supply by 5 per cent, as the meters support both time-of-use rates and critical peak pricing. Over 800,000 smart meters will be supplied to customers by 2007, and all 4.3 million homes in Toronto will have a smart meter by 2010. In order to meet targets for 2010, the utility will continue to install more 15,000 meters each month for the next 4 years. While the Ontario government has planned and coordinated the rollout and developed smart metering specifications and standards, Toronto Hydro is responsible for the purchase, installation, operation and maintenance of the meters. Advance testing of each meter is needed to ensure billing accuracy, and customer education on meter use is also. The complexity of the metering program has led the utility to establish a rigid project management process. Customer education pilot program are currently being conducted. Experience gained during the earlier phases of the program have enabled the utility to select appropriate metering systems based on density, topography and physical conditions. Project expenditures have been within budget due to improved project estimating and planning. The metering program has been conducted in tandem with the utility's peakSAVER program, a residential and small commercial load control program that has been successful in reducing summer peak demand by cycling air conditioners without causing discomfort. It was concluded that the utility will continue with its mass deployment of smart meters, and is currently preparing its call center to handled

  18. Evaluation of the apparent losses caused by water meter under-registration in intermittent water supply.

    Science.gov (United States)

    Criminisi, A; Fontanazza, C M; Freni, G; Loggia, G La

    2009-01-01

    Apparent losses are usually caused by water theft, billing errors, or revenue meter under-registration. While the first two causes are directly related to water utility management and may be reduced by improving company procedures, water meter inaccuracies are considered to be the most significant and hardest to quantify. Water meter errors are amplified in networks subjected to water scarcity, where users adopt private storage tanks to cope with the intermittent water supply. The aim of this paper is to analyse the role of two variables influencing the apparent losses: water meter age and the private storage tank effect on meter performance. The study was carried out in Palermo (Italy). The impact of water meter ageing was evaluated in laboratory by testing 180 revenue meters, ranging from 0 to 45 years in age. The effects of the private water tanks were determined via field monitoring of real users and a mathematical model. This study demonstrates that the impact on apparent losses from the meter starting flow rapidly increases with meter age. Private water tanks, usually fed by a float valve, overstate meter under-registration, producing additional apparent losses between 15% and 40% for the users analysed in this study.

  19. Preliminary assessment of interand intraobserver reproducibility, and normative values of renal mean transit time (MTT) and parenchymal transit time (PTT) for 99mTc-etylenodicysteine.

    Science.gov (United States)

    Cichocki, Paweł; Surma, Marian; Woźnicki, Wojciech; Bieńkiewicz, Małgorzata; Płachcińska, Anna; Kuśmierek, Jacek

    2015-01-01

    The clinical significance of MTT and PTT, determined by deconvolution of renographic curves, is arguable. Their usefulness in diagnosis of obstructive uro- and nephropathy, renovascular hypertension and monitoring of transplanted kidneys is pointed out, but susceptibility of deconvolution methods to errors resulting from "statistical noise" is also stressed. So far there are no reports on normative MTT values for 99mTc-EC, although such values were already determined for ¹³¹I-OIH, 99mTc-DTPA and 99mTc-MAG3. The aim of this study is an assessment of inter- and intraobserver reproducibility of MTT and PTT for 99mTc-EC, and determination of normative values for these parameters. 31 patients (17 women and 14 men aged 19-75, average 44 years) referred for dynamic renal scintigraphy with: unilateral flow impairment (11), unilateral nephrolithiasis (2), control after unilateral lithotripsy (4), moderate hypertension (demographically with > 99% probability of primary hypertension) (4), suspected cirrhosis of one kidney (3), future kidney donors (3), control after abdominal injuries (3), incontinence (1). 42 functionally efficient kidneys were included in the study. Criteria for recognition of a kidney as functionally efficient were: - no earlier history of renal disease, signs of renal damage in basic blood and urine tests, or abnormalities in ultrasonography; - normal result of dynamic renal scintigraphy (in terms of sequential images and renographic curve). MTT and PTT values were determined independently by two operators, using a matrix method for deconvolution of renographic curves. Differences between mean MTT and PTT from two studies by one operator were insignificant and those values were closely correlated (r = 0.99 and r = 0.97, respectively). Differences of values obtained by both operators were practically insignificant for MTT (r = 0.93), and significant for PTT (r = 0.81 and p operator - 200 s and 170 s, respectively. The procedure of processing dynamic

  20. Influence of a subsequent meal on the oro-cecal transit time of a solid test meal

    NARCIS (Netherlands)

    Priebe, MG; Wachters-Hagedoorn, RE; Landman, K; Heimweg, J; Elzinga, H; Vonk, RJ

    Oro-cecal transit time (OCTT) is determined for clinical diagnostics of intestinal complaints and research purposes. Ingestion of a subsequent meal during the test period shortens the OCTT of a liquid test meal (glucose solution), as previously reported. This study was conducted to determine whether

  1. Estimating subsurface water volumes and transit times in Hokkaido river catchments, Japan, using high-accuracy tritium analysis

    Science.gov (United States)

    Gusyev, Maksym; Yamazaki, Yusuke; Morgenstern, Uwe; Stewart, Mike; Kashiwaya, Kazuhisa; Hirai, Yasuyuki; Kuribayashi, Daisuke; Sawano, Hisaya

    2015-04-01

    The goal of this study is to estimate subsurface water transit times and volumes in headwater catchments of Hokkaido, Japan, using the New Zealand high-accuracy tritium analysis technique. Transit time provides insights into the subsurface water storage and therefore provides a robust and quick approach to quantifying the subsurface groundwater volume. Our method is based on tritium measurements in river water. Tritium is a component of meteoric water, decays with a half-life of 12.32 years, and is inert in the subsurface after the water enters the groundwater system. Therefore, tritium is ideally suited for characterization of the catchment's responses and can provide information on mean water transit times up to 200 years. Only in recent years has it become possible to use tritium for dating of stream and river water, due to the fading impact of the bomb-tritium from thermo-nuclear weapons testing, and due to improved measurement accuracy for the extremely low natural tritium concentrations. Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments and estimating subsurface water volume. While many tritium transit time studies have been conducted in New Zealand, only a limited number of tritium studies have been conducted in Japan. In addition, the meteorological, orographic and geological conditions of Hokkaido Island are similar to those in parts of New Zealand, allowing for comparison between these regions. In 2014, three field trips were conducted in Hokkaido in June, July and October to sample river water at river gauging stations operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). These stations have altitudes between 36 m and 860 m MSL and drainage areas between 45 and 377 km2. Each sampled point is located upstream of MLIT dams, with hourly measurements of precipitation and river water levels enabling us to distinguish between the snow melt and baseflow contributions

  2. Short-Term Interferential Transabdominal Electrical Stimulation Did Not Change Oral-Rectal Transit Time in Piglets.

    Science.gov (United States)

    Tan, Andre Y F; Sourial, Magdy; Hutson, John M; Southwell, Bridget R

    2018-03-02

    Transcutaneous electrical stimulation (TES) using interferential current (IFC) is a new therapeutic treatment for constipation. Clinical studies show that TES-IFC for 3-6 months improves colonic transit, but it is not clear if short-term stimulation affects transit or the effect requires longer to develop. The aim of this study was to determine if TES-IFC for only four days affects oral-rectal transit time in healthy pigs. Twenty-two 4-5-week old large white female piglets had transit studies during week 4 and week 5 by placing a capsule containing 18 radiopaque plastic markers in the esophagus under anesthetic followed by x-rays at 6, 30, 54, and 78 hours. Animals were randomly assigned to active or control groups. The active group received TES for 30 min daily for four days. Interferential current was applied through four electrodes (4 × 4 cm), with two para-spinal just below the last rib and two on the belly at the same level. Stimulation was at 4000 Hz and 4080-4160 Hz with currents crossing through the abdominal cavity. Whole bowel transit times ranged from 7.7 to 72.2 hours, stomach transit from transit time from 5 to 53 hours. Transit times were the same for the control (median 28.4 hours) and TES-IFC (23.0 hours) groups in the prestimulation and stimulation weeks (control 23.0, TES-IFC 19.8 hours) with no change within or between groups. Four days of half-hour TES-IFC daily in healthy 5-week-old piglets did not change oral-rectal transit time. © 2018 International Neuromodulation Society.

  3. Too cheap to meter what?

    International Nuclear Information System (INIS)

    Wedekind, Lothar

    2004-01-01

    Full text: 50 years ago, at 17:30 hours, 26 June 1954, in the town of Obninsk, near Moscow, the first nuclear power plant sent electricity to residences and businesses. Atomic energy had crossed the divide from military uses to peaceful ones, demonstrating the potential to fuel civilian electric power plants. The milestone is being marked this year at an IAEA international nuclear power conference in Obninsk. Past experience will be reviewed, but the focus is on meeting future challenges. Though it has come a long way in 50 years, nuclear energy today finds itself in a struggle of the fittest to carve a niche over the next fifty - in the marketplace and in the public eye. Cliches and sound bites tell part of the nuclear story. Visionary talk by nuclear proponents in 1954 was about future energy sources that would be 'too cheap to meter', a phrase critics pounced upon. Today in 2004 the 'too cheap to meter' phrase occasionally haunts the atom, but pops up more often than not in promotional ads for anything from wind power to web sites. Talk of nuclear energy now is of a 'renaissance' and 'second wind.' New nuclear plants are most attractive where energy demand is growing and resources are scarce, and where energy security, air pollution and greenhouse gases are priorities, IAEA Director General Mohamed ElBaradei points out. In cities, towns, and villages, reality is different, or too much the same, depending how you see and live it. Cheap or not, nuclear energy today supplies one-sixth of the world's electricity in some 30 countries. Still, it does not produce enough power. Neither does any other energy source. More than 1.5 billion people have no electricity to meter whatsoever - not from renewables, solar, nuclear, biomass, wind, coal, oil, gas, firewood, or hydrogen, the publicized promise of tomorrow. So what will it take? Maybe bigger blackouts or hotter days than the world has seen. Certainly needed are more attention, action, and money. In dollar terms

  4. DETERMINATION OF HYDRAULIC TURBINE EFFICIENCY BY MEANS OF THE CURRENT METER METHOD

    Directory of Open Access Journals (Sweden)

    PURECE C.

    2016-12-01

    Full Text Available The paper presents methodology used for determining the efficiency of a low head Kaplan hydraulic turbine with short converging intake. The measurement method used was the current meters method, the only measurement method recommended by the IEC 41standard for flow measurement in this case. The paper also presents the methodology used for measuring the flow by means of the current meters method and the various procedures for calculating the flow. In the last part the paper presents the flow measurements carried out on the Fughiu HPP hydraulic turbines for determining the actual operating efficiency.

  5. Determination of regional flow by use of intravascular PET tracers: microvascular theory and experimental validation for pig livers

    DEFF Research Database (Denmark)

    Munk, O L; Bass, L; Feng, H

    2003-01-01

    . In particular, the early dynamic phase after a tracer bolus injection was much improved. The regional hepatic blood flow estimates provided by the microvascular models (1.3 +/- 0.3 mL min(-1) mL(-1) for the single-capillary model and 1.14 +/- 0.14 min(-1) mL(-1) for the multiple-capillary model) (mean +/- SEM m...... with the standard model in a pig liver study. METHODS: Eight pigs underwent a 5-min dynamic PET study after (15)O-carbon monoxide inhalation. Throughout each experiment, hepatic arterial blood and portal venous blood were sampled, and flow was measured with transit-time flow meters. The hepatic dual......L of blood min(-1) mL of liver tissue(-1)) were in agreement with the total blood flow measured by flow meters and normalized to liver weight (1.03 +/- 0.12 mL min(-1) mL(-1)). CONCLUSION: Compared with the standard compartment model, the 2 microvascular models provide a superior description of tissue...

  6. Performance of Virtual Current Meters in Hydroelectric Turbine Intakes

    Energy Technology Data Exchange (ETDEWEB)

    Harding, Samuel F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group; Romero-Gomez, Pedro D. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group; Richmond, Marshall C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group

    2016-04-30

    Standards provide recommendations for the best practices in the installation of current meters for measuring fluid flow in closed conduits. These include PTC-18 and IEC-41 . Both of these standards refer to the requirements of the ISO Standard 3354 for cases where the velocity distribution is assumed to be regular and the flow steady. Due to the nature of the short converging intakes of Kaplan hydroturbines, these assumptions may be invalid if current meters are intended to be used to characterize turbine flows. In this study, we examine a combination of measurement guidelines from both ISO standards by means of virtual current meters (VCM) set up over a simulated hydroturbine flow field. To this purpose, a computational fluid dynamics (CFD) model was developed to model the velocity field of a short converging intake of the Ice Harbor Dam on the Snake River, in the State of Washington. The detailed geometry and resulting wake of the submersible traveling screen (STS) at the first gate slot was of particular interest in the development of the CFD model using a detached eddy simulation (DES) turbulence solution. An array of virtual point velocity measurements were extracted from the resulting velocity field to simulate VCM at two virtual measurement (VM) locations at different distances downstream of the STS. The discharge through each bay was calculated from the VM using the graphical integration solution to the velocity-area method. This method of representing practical velocimetry techniques in a numerical flow field has been successfully used in a range of marine and conventional hydropower applications. A sensitivity analysis was performed to observe the effect of the VCM array resolution on the discharge error. The downstream VM section required 11–33% less VCM in the array than the upstream VM location to achieve a given discharge error. In general, more instruments were required to quantify the discharge at high levels of accuracy when the STS was

  7. Characterization of mean transit time at large springs in the Upper Colorado River Basin, USA: A tool for assessing groundwater discharge vulnerability

    Science.gov (United States)

    Solder, John; Stolp, Bernard J.; Heilweil, Victor M.; Susong, David D.

    2016-01-01

    Environmental tracers (noble gases, tritium, industrial gases, stable isotopes, and radio-carbon) and hydrogeology were interpreted to determine groundwater transit-time distribution and calculate mean transit time (MTT) with lumped parameter modeling at 19 large springs distributed throughout the Upper Colorado River Basin (UCRB), USA. The predictive value of the MTT to evaluate the pattern and timing of groundwater response to hydraulic stress (i.e., vulnerability) is examined by a statistical analysis of MTT, historical spring discharge records, and the Palmer Hydrological Drought Index. MTTs of the springs range from 10 to 15,000 years and 90 % of the cumulative discharge-weighted travel-time distribution falls within the range of 2−10,000 years. Historical variability in discharge was assessed as the ratio of 10–90 % flow-exceedance (R 10/90%) and ranged from 2.8 to 1.1 for select springs with available discharge data. The lag-time (i.e., delay in discharge response to drought conditions) was determined by cross-correlation analysis and ranged from 0.5 to 6 years for the same select springs. Springs with shorter MTTs (<80 years) statistically correlate with larger discharge variations and faster responses to drought, indicating MTT can be used for estimating the relative magnitude and timing of groundwater response. Results indicate that groundwater discharge to streams in the UCRB will likely respond on the order of years to climate variation and increasing groundwater withdrawals.

  8. Discharge Measurements in Shallow Urban Streams Using a Hydroacoustic Current Meter

    Science.gov (United States)

    Fisher, G.T.; Morlock, S.E.; ,

    2002-01-01

    Hydroacoustic current-meter measurements were evaluated in small urban streams under a range of stages, velocities, and channel-bottom materials. Because flow in urban streams is often shallow, conventional mechanical current-meter measurements are difficult or impossible to make. The rotating-cup Price pygmy meter that is widely used by the U.S. Geological Survey and other agencies should not be used in depths below 0.20 ft and velocities less than 0.30 ft/s. The hydroacoustic device provides measurements at depths as shallow as 0.10 ft and velocities as low as 0.10 ft/s or less. Measurements using the hydroacoustic current meter were compared to conventional discharge measurements. Comparisons with Price-meter measurements were favorable within the range of flows for which the meters are rated. Based on laboratory and field tests, velocity measurements with the hydroacoustic cannot be validated below about 0.07 ft/s. However, the hydroacoustic meter provides valuable information on direction and magnitude of flow even at lower velocities, which otherwise could not be measured with conventional measurements.

  9. Off-level corrections for gravity meters

    Science.gov (United States)

    Niebauer, T. M.; Blitz, Thomas; Constantino, Andy

    2016-04-01

    Gravity meters must be aligned with the local gravity at any location on the surface of the earth in order to measure the full amplitude of the gravity vector. The gravitational force on the sensitive component of the gravity meter decreases by the cosine of the angle between the measurement axis and the local gravity vector. Most gravity meters incorporate two horizontal orthogonal levels to orient the gravity meter for a maximum gravity reading. In order to calculate a gravity correction it is often necessary to estimate the overall angular deviation between the gravity meter and the local gravity vector using two measured horizontal tilt meters. Typically this is done assuming that the two horizontal angles are independent and that the product of the cosines of the horizontal tilts is equivalent to the cosine of the overall deviation. These approximations, however, break down at large angles. This paper derives analytic formulae to transform angles measured by two orthogonal tilt meters into the vertical deviation of the third orthogonal axis. The equations can be used to calibrate the tilt sensors attached to the gravity meter or provide a correction for a gravity meter used in an off-of-level condition.

  10. Characterization of type, position and dimension of flaws by transit time locus curves of ultrasonic inspections - ALOK. Pt. 2

    International Nuclear Information System (INIS)

    Grohs, B.; Barbian, O.A.; Kappes, W.; Paul, H.

    1981-01-01

    With automatic ultrasonic testing, flaws can be detected and described and thus characterized according to their type, position and dimensions. During scanning of a test object, the flaws are registered by many different pathways and many different acoustic irradiation directions. The transit time locus curve represents the distance between the relfecting points of a flaw and the source in dependence of the probe position; hence, information on flaw position and dimensions can be derived from this curve. If the sound velocity is known, the transit path can then be calculated from the transit time. This requires, above all, a constant sound velocity along the whole transit path. Various methods are presented for reconstructing the flaw border in the plane of incidence. (orig./RW) [de

  11. 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 are used to determine the photometric parameters and the physical properties of the GJ1214 system. Our results are in good agreement with published values. Individual times of mid-transit are measured with uncertainties as low as 10s, allowing us to reduce the uncertainty in the orbital period...... by a factor of two. Conclusions: A Bayesian analysis reveals that it is highly improbable that the observed transit times is explained by TTV, when compared with the simpler alternative of a linear ephemeris....

  12. Nonlinearities and transit times in soil organic matter models: new developments in the SoilR package

    Science.gov (United States)

    Sierra, Carlos; Müller, Markus

    2016-04-01

    SoilR is an R package for implementing diverse models representing soil organic matter dynamics. In previous releases of this package, we presented the implementation of linear first-order models with any number of pools as well as radiocarbon dynamics. We present here new improvements of the package regarding the possibility to implement models with nonlinear interactions among state variables and the possibility to calculate ages and transit times for nonlinear models with time dependencies. We show here examples on how to implement model structures with Michaelis-Menten terms for explicit microbial growth and resource use efficiency, and Langmuir isotherms for representing adsorption of organic matter to mineral surfaces. These nonlinear terms can be implemented for any number of organic matter pools, microbial functional groups, or mineralogy, depending on user's requirements. Through a simple example, we also show how transit times of organic matter in soils are controlled by the time-dependencies of the input terms.

  13. Study of the water transit time in the Tiete and Pinheiros rivers

    International Nuclear Information System (INIS)

    Agudo, E.G.; Santos, J.L. dos; Merighi Junior, A.; Sanchez, W.; Albuquerque, A.M.

    1976-01-01

    A study of the water time of travel in the Tiete and Pinheiros rivers was performed using radiotracer techniques. The section studied was about 50 Km long in the metropolotinan area of Sao Paulo City. The passage of the radioactive cloud was measured in several control sections between the injection point and the Pedreira dam in the Billings reservoir where the water from those rivers is pumped. The increase of rate flow along the way of the rivers, due to afluents and sewage contributions was calculated using the total count method. The flow rate of the principal afluents and the Tiete river where simultaneously measured using radiotracer techniques. The influence of several factors, as pumping rate in the pumping stations and rain water contribution are discussed [pt

  14. Change in mean transit time, apparent diffusion coefficient, and cerebral blood volume during pediatric diabetic ketoacidosis treatment.

    Science.gov (United States)

    Vavilala, Monica S; Marro, Ken I; Richards, Todd L; Roberts, Joan S; Curry, Parichat; Pihoker, Catherine; Bradford, Heidi; Shaw, Dennis

    2011-11-01

    Cerebral edema is a devastating complication of pediatric diabetic ketoacidosis. We examined measures describing potential causes of whole brain and regional brain edema (mean transit time, apparent diffusion coefficient, and relative cerebral blood volume) during treatment of diabetic ketoacidosis in children. Prospective observational study. Regional children's hospital. None. After Institutional Review Board approval, children admitted with diabetic ketoacidosis (pH 300 mg/dL, and ketosis) underwent two serial paired contrast-enhanced (gadolinium) and diffusion magnetic resonance imaging scans. Change in whole brain and regional (frontal lobe, occipital lobe, and basal ganglia) mean transit time, apparent diffusion coefficient, and relative cerebral blood volume between the two time periods (12-24 hrs) and (36-72 hrs) after start of insulin treatment (time 0) were determined. Thirteen children (median age, 10.3 ± 1.1 yrs; 7 female) with diabetic ketoacidosis were examined. Overall, whole brain and regional mean transit time decreased from time 1 (first magnetic resonance imaging after time 0) to time 2 (second magnetic resonance imaging after time 0) by 51% ± 59% (p = .01), without differences between the brain regions examined. Whole brain apparent diffusion coefficient increased by 4.7% ± 3.4% (p = .001), without differences between the brain regions examined. There was no change in relative cerebral blood volume for the whole brain and for the three brain regions examined. In this study, whole brain mean transit time decreased and apparent diffusion coefficient increased, suggesting a vasogenic process between the two study periods during diabetic ketoacidosis treatment.

  15. The Mean Transit Time of the CBD and Afferent Loop Using 99mTc-DISIDA Scintigram in Truncal Vagotomy

    International Nuclear Information System (INIS)

    Moon, Tae Young; Kim, Dong Soo

    1988-01-01

    The authors observed functional change of the CBD and the afferent loop with the transit time of 99m Tc-DISIDA scintigram in patients treated by the surgical operation of gastric ulcers and cancer at Busan National University Hospital from June, 1987 to April, 1988. So authors estimated the time between the peak activity of the CBD and the afferent loop (TCA), the half transit time of the CBD activity (t1/2 CBD) and the half transit time of the afferent loop activity (t1/2 A-loop) in 9 patients undergone truncal vagotomy, who have no specific symptoms at 2 to 6 months after the operation, 5 patients undergone the operation without truncal vagotomy, and 7 persons as a control group. The results were as follows: 1) In control group, the mean TCA, t1/2 CBD and t1/2 duodenum were 8.6±9.0 min., 38.7±17.3 min. and 28.6±10.9 min, respectively. 2) In the operation group without truncal vagotomy, the mean TCA, t1/2 CBD and t1/2 A-loop were 10.0±7.1min. 48.2±22.3 min. and 39.4±26.7 min. respectively. 3) In the operation group with truncal vagotomy, the mean TCA, t1/2 CBD and t1/2 A-loop were 15.0±8.7 min., 36.1±16.5 min. and 42.6±24.4 min, respectively. From the above results, we concluded that the transit time of the CBD and the afferent loop is not affected by truncal vagotomy.

  16. Effect of cheese on intestinal transit time and other indicators of bowel function in residents of a retirement home.

    Science.gov (United States)

    Mykkänen, H M; Karhunen, L J; Korpela, R; Salminen, S

    1994-01-01

    Effects of increased intake of cheese on intestinal transit time and other indicators of bowel function were studied in 21 retirement home residents (18 women and 3 men; age, 68-87 years). The study was divided into four succeeding periods: 1) 1-week basal period (usual diet); 2)3-week cheese period (extra cheese was offered as such on bread or used in cooking); 3) 3-week no-cheese period (all cheese on bread was replaced with cured meats and cold cuts, and no cheese was used in cooking); 4) 3-week follow-up period (usual diet). During the last week of each period a questionnaire was filled out on fecal frequencies, consistency of feces (soft, normal, hard), and occurrence of abdominal pain and flatulence. Use of laxative medications and therapeutic foods (prunes) was registered. Eleven of the 21 subjects collected fecal samples for the determination of fecal wet weight and intestinal transit time by means of radiopaque Sitzmark capsules. Intakes of cheese, fiber-containing foods, and fluids by these 11 subjects during meals offered in the cafeteria were recorded on a prefilled questionnaire. In spite of a 10-fold increase in the intake of cheese no change in intestinal transit time, fecal frequency, fecal wet weight, consistency of feces, and occurrence of gastrointestinal symptoms was observed. The use of laxative medication was higher during the cheese period, but no change in the combined use of laxative medication and therapeutic foods (prunes) was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Ultrasonic meters in the feedwater flow to recover thermal power in the reactor of nuclear power plant of Laguna Verde U1 and U2; Medidores ultrasonicos en el flujo de agua de alimentacion para recuperar potencia termica en el reactor de la Central Nuclear Laguna Verde U1 and U2

    Energy Technology Data Exchange (ETDEWEB)

    Tijerina S, F. [CFE, Central Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)]. e-mail: francisco.tijerina@cfe.gob.mx

    2008-07-01

    The engineers in nuclear power plants BWRs and PWRs based on the development of the ultrasonic technology for the measurement of the mass, volumetric flow, density and temperature in fluids, have applied this technology in two primary targets approved by the NRC: the use for the recovery of thermal power in the reactor and/or to be able to realize an increase of thermal power licensed in a 2% (MUR) by 1OCFR50 Appendix K. The present article mentions the current problem in the measurement of the feedwater flow with Venturi meters, which affects that the thermal balance of reactor BWRs or PWRs this underestimated. One in broad strokes describes the application of the ultrasonic technology for the ultrasonic measurement in the flow of the feedwater system of the reactor and power to recover thermal power of the reactor. One is to the methodology developed in CFE for a calibration of the temperature transmitters of RTD's and the methodology for a calibration of the venturi flow transmitters using ultrasonic measurement. Are show the measurements in the feedwater of reactor of the temperature with RTD's and ultrasonic measurement, as well as the flow with the venturi and the ultrasonic measurement operating the reactor to the 100% of nominal thermal power, before and after the calibration of the temperature transmitters and flow. Finally, is a plan to be able to realize a recovery of thermal power of the reactor, showing as carrying out their estimations. As a result of the application of ultrasonic technology in the feedwater of reactor BWR-5 in Laguna Verde, in the Unit 1 cycle 13 it was recover an equivalent energy to a thermal power of 25 MWt in the reactor and an exit electrical power of 6 M We in the turbogenerator. Also in the Unit 2 cycle 10 it was recover an equivalent energy to a thermal power of 40 MWt in the reactor and an exit electrical power of 16 M We in the turbogenerator. (Author)

  18. 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

  19. Ages and transit times as important diagnostics of model performance for predicting carbon dynamics in terrestrial vegetation models

    Directory of Open Access Journals (Sweden)

    V. Ceballos-Núñez

    2018-03-01

    Full Text Available 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

  20. Real-time algorithm for the measurement of liquid metal coolant flow velocity with correlated thermal signals

    International Nuclear Information System (INIS)

    Moazzeni, Taleb; Jiang, Yingtao; Ma, Jian; Li, Ning

    2009-01-01

    One flow meter was developed especially for the environment of high irradiation, pressure, and temperature. The transit time of natural random temperature fluctuation in process, for example nuclear reactor, can be obtained based on the cross-correlation method, which has already been shown that it is capable in situations where no other flow meter can be used. Thereby, the flow rate can be derived in pipe flow if the area of cross-section is known. In practice, the evaluation of the integrals over the measurement time in cross-correlation method will lead errors caused by peak detection from flat cross correlation coefficient distribution or additional peaks. One Auto-Adaptive Impulse Response Function estimation is introduced and significantly narrower peak will be obtained. Fiber optic sensors are advantageous for temperature measurements in the reactor pressure vessels. However, the corrosive coolant (as liquid lead/lead alloy or molten salt coolant) is a barrier of the optic sensor in such application. Thermocouple with grounded stainless steel shielding material would have same life time with structure material in reactor, although thermocouple has relatively slow response. The degradation due to corrosion/erosion will not introduce measurement error or necessary calibration, because only the correlation between signals is taken into consideration during measurements. Experiments conducted in a testing hydraulic facility approved the considerable improvement of accuracy by this new algorithm using thermocouple temperature sensors. (author)

  1. Simplified Processing Method for Meter Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, Kimberly M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Colotelo, Alison H. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Downs, Janelle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ham, Kenneth D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Henderson, Jordan W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Montgomery, Sadie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vernon, Christopher R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parker, Steven A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-11-01

    Simple/Quick metered data processing method that can be used for Army Metered Data Management System (MDMS) and Logistics Innovation Agency data, but may also be useful for other large data sets. Intended for large data sets when analyst has little information about the buildings.

  2. Evaluating Metal Probe Meters for Soil Testing.

    Science.gov (United States)

    Hershey, David R.

    1992-01-01

    Inexpensive metal probe meters that are sold by garden stores can be evaluated by students for their accuracy in measuring soil pH, moisture, fertility, and salinity. The author concludes that the meters are inaccurate and cannot be calibrated in standard units. However, the student evaluations are useful in learning the methods of soil analysis…

  3. Development of a contour meter

    International Nuclear Information System (INIS)

    Andrada C, F.A.; Sanz, D.E.

    2006-01-01

    The dosimetric calculation in patients that receive radiotherapy treatment it requires the one knowledge of the geometry of some anatomical portions, which differs from a patient to another. Making reference to the specific case of mammary neoplasia, one of the measurements that is carried out on the patient is the acquisition of the contour of the breast, which is determined from a point marked on the breastbone until another point marked on the lateral of the thorax, below the armpit, with the patient located in the irradiation position. This measurement is carried out with the help of a mechanical contour meter that is a device conformed by a series of wires with a polymeric coating, which support on the breast of the patient and it reproduces its form. Then it is transported in the more careful possible form on a paper and the contour is traced with a tracer one. The geometric error associated to this procedure is of ±1 cm, which is sensitive of being reduced. The present work finds its motivation in the patient's radiological protection radiotherapy. The maximum error in dose allowed in radiotherapeutic treatments is 5%. It would be increase the precision and with it to optimize the treatment received by the patient, reducing the error in the acquisition process of the mammary contour. With this objective, a digital device is designed whose operation is based in the application of a spatial transformation on a picture of the mammary contour, which corrects the geometric distortion introduced in the process of the photographic acquisition. An algorithm that allows to obtain a front image (without distortion) of the plane of the contour was developed. A software tool especially developed carries out the processing of the digital images. The maximum geometric error detected in the validation process is 2 mm located on a small portion of the contour. (Author)

  4. Measuring Your Peak Flow Rate

    Science.gov (United States)

    ... your child so they can help monitor your child's asthma symptoms . Why Should I Measure My Flow Rate? ... help parents determine what might be triggering their child's asthma. How Do You Use a Peak Flow Meter? ...

  5. Bandwidth Analysis of Smart Meter Network Infrastructure

    DEFF Research Database (Denmark)

    Balachandran, Kardi; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

    2014-01-01

    Advanced Metering Infrastructure (AMI) is a net-work infrastructure in Smart Grid, which links the electricity customers to the utility company. This network enables smart services by making it possible for the utility company to get an overview of their customers power consumption and also control...... to utilize smart meters and which existing broadband network technologies can facilitate this smart meter service. Initially, scenarios for smart meter infrastructure are identified. The paper defines abstraction models which cover the AMI scenarios. When the scenario has been identified a general overview...... of the bandwidth requirements are analysed. For this analysis the assumptions and limitations are defined. The results obtained by the analysis show, that the amount of data collected and transferred by a smart meter is very low compared to the available bandwidth of most internet connections. The results show...

  6. Hydro Ottawa achieves Smart Meter milestone

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    As Ontario's second largest municipal electricity company, Hydro Ottawa serves more than 285,000 residential and business customers in the city of Ottawa and the village of Casselman. Since 2006, the utility has installed more than 230,000 Smart Meters throughout its service territory in an effort to provide better services to its customers. This initiative represents the largest operational advanced metering infrastructure network in Canada. This move was necessary before time-of-use rates can be implemented in Ottawa. The Smart Meters deliver data wirelessly to Hydro Ottawa's Customer Information System for billing and eliminating manual readings. The Smart Meters are designed to promote more efficient use of electricity. The Government of Ontario has passed legislation requiring the installation of Smart Meters throughout the province by the end of 2010

  7. Inferring transit time distributions from atmospheric tracer data: Assessment of the predictive capacities of Lumped Parameter Models on a 3D crystalline aquifer model

    Science.gov (United States)

    Marçais, J.; de Dreuzy, J.-R.; Ginn, T. R.; Rousseau-Gueutin, P.; Leray, S.

    2015-06-01

    While central in groundwater resources and contaminant fate, Transit Time Distributions (TTDs) are never directly accessible from field measurements but always deduced from a combination of tracer data and more or less involved models. We evaluate the predictive capabilities of approximate distributions (Lumped Parameter Models abbreviated as LPMs) instead of fully developed aquifer models. We develop a generic assessment methodology based on synthetic aquifer models to establish references for observable quantities as tracer concentrations and prediction targets as groundwater renewal times. Candidate LPMs are calibrated on the observable tracer concentrations and used to infer renewal time predictions, which are compared with the reference ones. This methodology is applied to the produced crystalline aquifer of Plœmeur (Brittany, France) where flows leak through a micaschists aquitard to reach a sloping aquifer where they radially converge to the producing well, issuing broad rather than multi-modal TTDs. One, two and three parameters LPMs were calibrated to a corresponding number of simulated reference anthropogenic tracer concentrations (CFC-11, 85Kr and SF6). Extensive statistical analysis over the aquifer shows that a good fit of the anthropogenic tracer concentrations is neither a necessary nor a sufficient condition to reach acceptable predictive capability. Prediction accuracy is however strongly conditioned by the use of a priori relevant LPMs. Only adequate LPM shapes yield unbiased estimations. In the case of Plœmeur, relevant LPMs should have two parameters to capture the mean and the standard deviation of the residence times and cover the first few decades [0; 50 years]. Inverse Gaussian and shifted exponential performed equally well for the wide variety of the reference TTDs from strongly peaked in recharge zones where flows are diverging to broadly distributed in more converging zones. When using two sufficiently different atmospheric tracers like

  8. Transit time of river water in the Bering and Chukchi Seas estimated from δ18O and radium isotopes

    Science.gov (United States)

    Li, Qi; Chen, Min; Jia, Renming; Zeng, Jian; Lin, Hui; Zheng, Minfang; Qiu, Yusheng

    2017-12-01

    Seawater samples for the measurements of 226Ra, 228Ra and stable oxygen isotope (δ18O) were collected from the Bering and Chukchi Seas in the summer of 2014. The fractions of meteoric water (fMW) and sea-ice melted water (fSIM) were estimated based on the mass balance of salinity and δ18O with a three end-member mixing model. Our results showed that the average fMW increased northward from the Bering Basin to the Canada Basin while the fSIM distributed homogeneously. The lowest fMW and 228Ra/226Ra)A.R. values were found in the upper Bering Basin with little terrestrial input. The highest fMW but low 228Ra/226Ra)A.R. appeared in the northern Chukchi Sea and the Canada Basin, ascribing to the current-driven accumulation of freshwater and its long residence time. More abundant sea-ice melted water was found on the pack-ice edge, indicating the trap of earlier melted waters by the ice pack. Based upon the linear relationships between 228Ra/226Ra)A.R. and fMW in the Bering Shelf and the Chukchi Shelf, the transit time for the Pacific inflow was constrained. The transit time of river water from the Bering Shelf to the Chukchi Shelf was estimated as 0.2-4.4 years with an average of 1.6 ± 1.5 years, while that from the Chukchi Shelf to the Canada Basin was 10.2-13.2 years with an average of 11.8 ± 1.1 years. The spatial variation of the transit time was mainly affected by the current intensity. Our study highlights the importance of in-depth evaluation for the subarctic-arctic exchange.

  9. Digital reactivity meter for NPP Krsko

    International Nuclear Information System (INIS)

    Glumac, B.; Vidmar, M.; Ravnik, M.

    1984-01-01

    Digital or analog reactivity meter is needed in order to perform the necessary low power physics tests after core reload in a nuclear power plant. Nuclear power plant Krsko ordered the construction of such digital reactivity meter on the basis of 'mikro-m' modular computer system that has been developed by IJS. Input signal sampling model as well as realtime reactivity calculation on the basis of the reactor inverse kinetic equation have also been developed by IJS. This digital reactivity meter has already been used to perform the start-up tests in NPP Krsko following first reload in fall of 1983. (author)

  10. Hydrogen meter for service in liquid sodium

    International Nuclear Information System (INIS)

    McCown, J.J.

    1983-11-01

    This standard establishes the requirements for the design, materials, fabrication, quality assurance, examination, and acceptance testing of a hydrogen meter and auxiliary equipment for use in radioactive or nonradioactive liquid sodium service. The meter shall provide a continuous and accurate indication of the hydrogen impurity concentration over the range 0.03 to 10 ppM hydrogen in sodium at temperatures between 800 and 1000 0 F (427 and 538 0 C). The meter may also be used to rapidly monitor changes in hydrogen concentration, over the same concentration range, and, therefore can be used as a sensor for sodium-water reactions in LMFBR steam generators

  11. 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...

  12. 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.

  13. EMMNet: Sensor Networking for Electricity Meter Monitoring

    Directory of Open Access Journals (Sweden)

    Zhi-Ting Lin

    2010-06-01

    Full Text Available Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters.

  14. EMMNet: sensor networking for electricity meter monitoring.

    Science.gov (United States)

    Lin, Zhi-Ting; Zheng, Jie; Ji, Yu-Sheng; Zhao, Bao-Hua; Qu, Yu-Gui; Huang, Xu-Dong; Jiang, Xiu-Fang

    2010-01-01

    Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters.

  15. Opportunities for smart meters in Germany

    International Nuclear Information System (INIS)

    Wolff, J.

    2010-10-01

    Germany has the ambitious goal of lowering its CO2 emission with 80 percent until 2050 as compared to 1990. Sustainable energy and the deployment of smart meters are starting to play increasingly important roles. [nl

  16. VT USGS NED DEM (10 meter) - statewide

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This dataset is derived from the multi-resolution National Elevation Dataset (NED), at resolutions of both 1/3 arc-second (approx. 10 meters) and...

  17. USGS Digital Orthophoto Quad (DOQ) - 3 meter

    Data.gov (United States)

    Minnesota Department of Natural Resources — These data files are a collection of the USGS standard DOQs that have been resampled to a 3-meter cell resolution and mosaiced into quad format vs quarter quad...

  18. Informatics Solutions for Smart Metering Systems Integration

    Directory of Open Access Journals (Sweden)

    Simona-Vasilica OPREA

    2015-01-01

    Full Text Available In this paper different aspects regarding smart metering systems integration have been depicted. Smart metering systems, renewable energy sources integration and advanced tariff systems implementation require informatics solution that could automatically collect and process data, forecast the behavior of electricity consumers, analyze trends regarding electricity prices, optimize the consumption of consumers, provide friendly interfaces, etc. They are advanced technologies that represent solutions for insufficient conventional primary energy sources, gas emissions, dependency on energy sources located outside European Union and issues related to energy efficiency. This paper mainly describes several informatics solutions correlated with operational requirements for smart metering system and our proposal for simplified architecture of smart metering systems, with three distinct levels (base level, middle level and top level and load profile calculation methods.

  19. The model FT-3106 nuclide activity meter

    International Nuclear Information System (INIS)

    Yang Jianming

    1999-01-01

    The author describes the important role of the nuclide activity meter in scientific research, production, medicine and health and its general situation of development in the country. The working principle, structure and feature of the new model FT-3106 nuclide activity meter are presented through description of the measures to improve the properties and quality in research and design. Finally the situation of its popularization and application are given

  20. Capacitive level meter for liquid rare gases

    Science.gov (United States)

    Sawada, R.; Kikuchi, J.; Shibamura, E.; Yamashita, M.; Yoshimura, T.

    2003-08-01

    An international project to search μ→eγ decay includes the use of a liquid xenon gamma ray detector. So, a liquid level meter working at a low temperature with low outgassing is needed and the prototype is constructed. The meter shows the liquid level by measuring the capacitance between electrodes with small intervals immersed in the liquid. The operation was successful with the estimated precision of 1 mm in RMS or better.

  1. A local-velocity meter for hypersonic plasma jet

    International Nuclear Information System (INIS)

    Nyazev, A.A.; Lerner, N.B.; Svinolupov, K.I.

    1985-01-01

    This paper describes a system for a resonant laser Doppler meter for the local velocity in a hypersonic plasma flow. Preliminary test results on the prototype are reported for a jet of air containing sodium at 1100 degrees K, air pressure in the working region 20-200 Pa, and jet speed 6-8 km/sec. Measured speeds agree with theoretical predictions. The prototype and the method do not impose constraints on the working conditions but can be extended to wide ranges in temperature and pressure, such as ones in which the line width does not exceed the Doppler shift

  2. Radiographic anatomy and barium sulfate contrast transit time of the gastrointestinal tract of bearded dragons (Pogona vitticeps).

    Science.gov (United States)

    Grosset, Claire; Daniaux, Lise; Guzman, David Sanchez-Migallon; Weber, Ernest Scott; Zwingenberger, Allison; Paul-Murphy, Joanne

    2014-01-01

    The positive contrast gastrointestinal study is a common non-invasive diagnostic technique that does not require anesthesia and enables good visualization of the digestive tract. Radiographic anatomy and reference intervals for gastrointestinal contrast transit time in inland bearded dragons (Pogona vitticeps) were established using seven animals administered 15 ml/kg of a 35% w/v suspension of barium by esophageal gavage. Dorso-ventral and lateral radiographic views were performed at 0, 15, 30 min, 1, 2, 4, 6, 8, 12 h, and then every 12 h up to 96 h after barium administration. Gastric emptying was complete at a median time of 10 h (range 4-24 h). Median jejunum and small intestinal emptying times were 1 h (range 30 min-2 h) and 29 h (range 24-48 h), respectively. Median transit time for cecum was 10 h (range 8-12 h). Median time for contrast to reach the colon was 31 h (range 12-72 h) after administration. Results were compared to those obtained in other reptilian species. This technique appeared safe in fasted bearded dragons and would be clinically applicable in other lizard species.

  3. Radiographic-anatomical aspects and gastrointestinal transit time in the spectacled caiman Caiman crocodilus crocodilus (Linnaeus, 1758 (Crocodylia, Alligatoridae

    Directory of Open Access Journals (Sweden)

    Heloisa Castro Pereira

    2014-09-01

    Full Text Available In Brazil, there is increasing interest in the establishment of captive breeding programs for caiman. However, there is a paucity of in-depth studies on the proper care of these reptiles in captivity, particularly regarding optimal food type and frequency of feeding. The purpose of this study was to determine radiographic-anatomical aspects of, and gastrointestinal transit time of Caiman crocodilus crocodilus using contrast radiography. Ten caiman were used in the study, five males and five females, the animals were physically restrained for administration of a radiographic contrast medium, consisting of 10 ml/kg barium sulfate and mineral oil suspension (70%: 30% respectively, via the orogastric tube. Following contrast medium administration, radiographs were taken via dorsoventral projection first at five minutes, then at 6, 24, 30, 48, 54, 72, 80, 96, 104, 120, 130, 144 and 150 hours. This technique allows visualization of contrast medium passage through the GI tract, which enabled determination of gastrointestinal transit time in the spectacled caiman. The average time for contrast medium passage through the digestive tract of this species was 117 ± 29.6 h for females and 86.4 ± 21.5 h for males.

  4. Automatic determination of L/H transition times in DIII-D through a collaborative distributed environment

    International Nuclear Information System (INIS)

    Farias, G.; Vega, J.; González, S.; Pereira, A.; Lee, X.; Schissel, D.; Gohil, P.

    2012-01-01

    Highlights: ► An automatic predictor of L/H transition times has been implemented for the DIII-D tokamak. ► The system predicts the transition combining two techniques: a morphological pattern recognition algorithm and a support vector machines multi-layer model. ► The predictor is employed within a collaborative distributed computing environment. The system is trained remotely in the Ciemat computer cluster and operated on the DIII-D site. - Abstract: An automatic predictor of L/H transition times has been implemented for the DIII-D tokamak. The system predicts the transition combining two techniques: A morphological pattern recognition algorithm, which estimates the transition based on the waveform of a Dα emission signal, and a support vector machines multi-layer model, which predicts the L/H transition using a non-parametric model. The predictor is employed within a collaborative distributed computing environment. The system is trained remotely in the Ciemat computer cluster and operated on the DIII-D site.

  5. Food transit time, nutrient digestibility and nitrogen retention in farmed and feral American mink (Neovison vison)--a comparative analysis.

    Science.gov (United States)

    Gugołek, A; Zalewski, D; Strychalski, J; Konstantynowicz, M

    2013-12-01

    The aim of this study was to determine whether farming leads to changes in gastrointestinal function and nitrogen metabolism in farmed mink (FA), as compared with their wild-living counterparts. Three digestibility and balance trials were carried out. Experiment I was performed in May, and experiments II and III were conducted in September 2011. Farmed mink with the standard coat colour were purchased from a production farm in south-eastern Poland. Feral mink were harvested using cages in the hunting grounds of the Polish Hunting Association, Branch in Olsztyn. The experimental materials comprised of the following: trial I - adult males (eight animals per group), trial II - young females (six animals per group), trial III-young animals (five males and five females per group). Food transit time was measured during digestibility trials, on 10 consecutive days. The coefficients of nutrient and energy digestibility and daily nitrogen balance values were compared between groups in each experiment. It was found that farming contributed to changes in gastrointestinal function and nitrogen metabolism in mink. Farmed animals were characterized by a longer bowel transit time, a tendency towards higher nutrient digestibility and higher nitrogen retention, which resulted from selection for higher productivity. © 2012 Blackwell Verlag GmbH.

  6. Aggregation effects on tritium-based mean transit times and young water fractions in spatially heterogeneous catchments and groundwater systems

    Directory of Open Access Journals (Sweden)

    M. K. Stewart

    2017-09-01

    Full Text Available Kirchner (2016a demonstrated that aggregation errors due to spatial heterogeneity, represented by two homogeneous subcatchments, could cause severe underestimation of the mean transit times (MTTs of water travelling through catchments when simple lumped parameter models were applied to interpret seasonal tracer cycle data. Here we examine the effects of such errors on the MTTs and young water fractions estimated using tritium concentrations in two-part hydrological systems. We find that MTTs derived from tritium concentrations in streamflow are just as susceptible to aggregation bias as those from seasonal tracer cycles. Likewise, groundwater wells or springs fed by two or more water sources with different MTTs will also have aggregation bias. However, the transit times over which the biases are manifested are different because the two methods are applicable over different time ranges, up to 5 years for seasonal tracer cycles and up to 200 years for tritium concentrations. Our virtual experiments with two water components show that the aggregation errors are larger when the MTT differences between the components are larger and the amounts of the components are each close to 50 % of the mixture. We also find that young water fractions derived from tritium (based on a young water threshold of 18 years are almost immune to aggregation errors as were those derived from seasonal tracer cycles with a threshold of about 2 months.

  7. The effect of water temperature on food transit time and digestive enzymes activity in Caspian kutum (Rutilus kutum larvae

    Directory of Open Access Journals (Sweden)

    Nahid Ghysvandi

    2014-07-01

    Full Text Available The present study investigates the effects of water temperature on digestive enzymes activity and food transit time in Caspian kutum (Rutilus kutum larvae. Caspian kutum larvae (532 ± 0.05 and 543 ± 0.02 mg were divided into two groups with three replicates and reared at different water temperature i.e. 25.6 ± 0.4°C (T1 and 18.4 ± 0.1°C (T2. At the end of the experiment, sampling of intestine was performed at 0, 1, 3, 5, 8, 16, 24 and 30 h after feeding from each treatment. In T2, food was observed until 24 h after feeding and the intestine was empty 29 h after feeding, while in T1 19 h after feeding the intestine was empty. Digestive enzymes activities were higher in T2 treatment. The peaks of trypsin and alkaline phosphatase enzymes activity were found 8 h after feeding in T1, while occurred 16 h after feeding in T2. The highest chymotrypsin and alpha-amylase enzymes activity were observed 5 and 8h after feeding in T1 and T2, respectively. These results confirmed remarkable effects of temperature on food transit time and digestive enzymes activity of Caspian kutum.

  8. Intelligent Metering for Urban Water: A Review

    Directory of Open Access Journals (Sweden)

    Rodney Stewart

    2013-07-01

    Full Text Available This paper reviews the drivers, development and global deployment of intelligent water metering in the urban context. Recognising that intelligent metering (or smart metering has the potential to revolutionise customer engagement and management of urban water by utilities, this paper provides a summary of the knowledge-base for researchers and industry practitioners to ensure that the technology fosters sustainable urban water management. To date, roll-outs of intelligent metering have been driven by the desire for increased data regarding time of use and end-use (such as use by shower, toilet, garden, etc. as well as by the ability of the technology to reduce labour costs for meter reading. Technology development in the water sector generally lags that seen in the electricity sector. In the coming decade, the deployment of intelligent water metering will transition from being predominantly “pilot or demonstration scale” with the occasional city-wide roll-out, to broader mainstream implementation. This means that issues which have hitherto received little focus must now be addressed, namely: the role of real-time data in customer engagement and demand management; data ownership, sharing and privacy; technical data management and infrastructure security, utility workforce skills; and costs and benefits of implementation.

  9. Designing remote web-based mechanical-volumetric flow meter ...

    African Journals Online (AJOL)

    ... sudden increase in consumption is spotted an alarm goes off in web based software, announcing the possible fractures in transmission lines and prevents water loss and other damage and also provides the ability to control and manage consumption. In this project, it is planned so that by using renewable energy sources, ...

  10. Upper Meter Processes: Short Wind, Waves, Surface Flow and Turbulence

    National Research Council Canada - National Science Library

    Klinke, Jochen

    2001-01-01

    This work is an extension of the early works on measuring short wind waves that have been funded by ONR for seven years, During this seven-year period, we have collected the only available systematic...

  11. Compact, High-Accuracy Oxygen Flow Meter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Life support systems for future space suits will require advanced instrumentation to enable use of the suit for multiple missions. We propose to develop an oxygen...

  12. 16 reference population equations using peak expiratory flow meters

    African Journals Online (AJOL)

    DR. AMINU

    Many formulae for predicting lung function values for Nigerians have been produced by a lot of investigators. The same principle ... equations in current use are based on linear statistical models which are subject to change and they did not express the .... that present lower limits of normal or present information from which ...

  13. Reference population equations using peak expiratory flow meters ...

    African Journals Online (AJOL)

    Many formulae for predicting lung function values for Nigerians have been produced by a lot of investigators. The same principle but different statistical methods were adopted by different authors in generating these equations, hence the variability observed among these formulae. Most equations in current use are based on ...

  14. 16 reference population equations using peak expiratory flow meters

    African Journals Online (AJOL)

    DR. AMINU

    Department of Human Physiology Faculty of Medicine, Bayero University, Kano. ABSTRACT. Many formulae for predicting lung function values for Nigerians have been produced by a lot of investigators. The same principle but different statistical methods were adopted by different authors in generating these equations, ...

  15. Smart meters. Smart metering. A solution module for a future-oriented energy system; Intelligente Zaehler. Smart Metering. Ein Loesungsbaustein fuer ein zukunftsfaehiges Energiesystem

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, Nadia; Seidl, Hans (comps.)

    2011-12-15

    The German Energy Agency GmbH (Berlin, Federal Republic of Germany) reports on smart metering as a solution module for a future-oriented energy system by means of the following contributions: (1) Key role for smart meters; (2) What is smart metering? (3) Implementation of smart metering in Europe; (4) The market development to date in Germany; (5) Practical experiences with smart metering in Germany; (6) Frequently asked questions; (7) Smart metering in intelligent networks; (8) Legal framework conditions; (9) Data security and data protection in the utilisation of smart meters; (10) Ongoing information; (11) Efficient energy systems.

  16. A Light-Weight Metering File System for Sustainable Real-Time Meter Data Management

    Directory of Open Access Journals (Sweden)

    Gangman Yi

    2014-09-01

    Full Text Available A real-time smart metering system has strict requirements, since every piece of data gathered from various meters every hour is of importance, and each component consisting of metering infrastructure should be sustainable. Therefore, it is necessary to efficiently manage the meter data set in smart metering networks as well as in a server. Therefore, we propose a dedicated file system, a LIght-weight Metering File System (LIMFS, which is capable of not only efficiently storing and searching meter data but also performing distributed fault-tolerant meter data management for real-time smart meter devices. The proposed LIMFS exploits accumulated data sliding storage (ADSS for lost data recovery and latest-first error-ignorant data management (LEDM to reduce memory wastage, coping with dynamic report interval. Experimental results demonstrate that LIMFS has as a small enough overhead to be considered negligible, and provides flexible memory capacity according to dynamic report interval, in spite of lost data recovery functionality.

  17. Value of Abdominal Radiography, Colonic Transit Time, and Rectal Ultrasound Scanning in the Diagnosis of Idiopathic Constipation in Children: A Systematic Review

    NARCIS (Netherlands)

    Berger, Marjolein Y.; Tabbers, Merit M.; Kurver, Miranda J.; Boluyt, Nicole; Benninga, Marc A.

    2012-01-01

    Objective To perform a systematic review evaluating the value of abdominal radiography, colonic transit time (CTT), and rectal ultrasound scanning in the diagnosis of idiopathic constipation in children. Study design Eligible studies were those assessing diagnostic accuracy of abdominal radiography,

  18. Value of Abdominal Radiography, Colonic Transit Time, and Rectal Ultrasound Scanning in the Diagnosis of Idiopathic Constipation in Children : A Systematic Review

    NARCIS (Netherlands)

    Berger, Marjolein Y.; Tabbers, Merit M.; Kurver, Miranda J.; Boluyt, Nicole; Benninga, Marc A.

    Objective To perform a systematic review evaluating the value of abdominal radiography, colonic transit time (CTT), and rectal ultrasound scanning in the diagnosis of idiopathic constipation in children. Study design Eligible studies were those assessing diagnostic accuracy of abdominal radiography,

  19. Central aortic blood pressure, augmentation index, and reflected wave transit time: reproducibility and repeatability of data obtained by oscillometry

    Directory of Open Access Journals (Sweden)

    Ageenkova O

    2011-11-01

    Full Text Available Olga A Ageenkova, Marina A Purygina Department of Therapy, Functional and Ultrasound Diagnostics, Postgraduate Training Faculty of Smolensk State Medical Academy, Smolensk, Russian Federation Background: The evidence suggests that arterial stiffness acts as an independent predictor of general as well as cardiovascular mortality, strokes in patients with arterial hypertension, type 2 diabetes mellitus in the elderly, and in the general population. The oscillometric method measures parameters of arterial stiffness by applying special methods of processing oscillograms. This is a study of the reproducibility and repeatability of central aortic systolic blood pressure (SBP, augmentation index, and reflected wave transit time measured by Vasotens® technology. Methods: Anthropometric and hemodynamic measurements for 90 volunteers were made by two observers using the 24-hour blood pressure monitoring system, BPLab®, with Vasotens technology in "office" mode, over a period of two days and always at the same time in the morning. Initialization of the device was performed prior to each measurement cycle for each participant. Results: Analysis of short-term repeatability and reproducibility data for central aortic systolic blood pressure, reflected wave transit time, and augmentation index did not reveal any statistically significant differences. For observer A, SBP was 0.11 ± 7.53 mmHg and aortic SBP was 0.26 ± 6.11 mmHg; for observer B, SBP was 0.14 ± 8.42 and aortic SBP was 0.2 ± 7.25 mmHg. Short-term reproducibility for the different observers with averaging of both measurements was 0.36 ± 5.69 mmHg for SBP and 0.37 ± 6.7 mmHg for aortic SBP; the next day, repeatability for observer A was 0.52 ± 10.7 mmHg for SBP and 0.73 ± 8.98 mmHg for aortic SBP. Conclusion: BPLab with Vasotens technology has good reproducibility and repeatability, and can be recommended for clinical vascular risk estimation. Keywords: arterial stiffness, central aortic

  20. The 4-meter lunar engineering telescope

    Science.gov (United States)

    Peacock, Keith; Giannini, Judith A.; Kilgus, Charles C.; Bely, Pierre Y.; May, B. Scott; Cooper, Shannon A.; Schlimm, Gerard H.; Sounder, Charles; Ormond, Karen; Cheek, Eric

    1991-09-01

    The 16-meter diffraction limited lunar telescope incorporates a primary mirror with 312 one-meter segments; 3 nanometer active optics surface control with laser metrology and hexapod positioners; a space frame structure with one-millimeter stability; and a hexapod mount for pointing. The design data needed to limit risk in this development can be obtained by building a smaller engineering telescope on the moon with all of the features of the 16-meter design. This paper presents a 4.33-meter engineering telescope concept developed by the Summer 1990 Student Program of the NASA/JHU Space Grant Consortium Lunar Telescope Project. The primary mirror, made up of 18 one-meter hexagonal segments, is sized to provide interesting science as well as engineering data. The optics are configured as a Ritchey-Chretien with a coude relay to the focal plane beneath the surface. The optical path is continuously monitored with 3-nanometer precision interferometrically. An active optics processor and piezoelectric actuators operate to maintain the end-to-end optical configuration established by wave front sensing using a guide star. The mirror segments, consisting of a one-centimeter thick faceplate on 30-cm deep ribs, maintain the surface figure to a few nanometers under lunar gravity and thermal environment.

  1. Anti-Theft Automatic Metering Interface

    Directory of Open Access Journals (Sweden)

    Abhijeet Das

    2015-08-01

    Full Text Available Abstract Electricity is now more than a necessity and its need is increasing day by day resulting in power theft and power scarcity. The purpose of this project is to provide automatic control and monitoring of the Domestic Energy Meter enabling the Electricity Department to read meter readings without anyone visiting each house and also prevent electricity theft .This can be achieved by the use of a Microcontroller Unit that continuously monitors and records the Energy Meter readings in its permanent memory location. This system also makes use of a GSM module for remote monitoring and control of Energy Meter with the help of an interfacing circuitry. The Microcontroller based system continuously records the readings and the live meter reading can be sent to the Electricity department after a count period or on request. This system also can be used to disconnect the power supply to the house in case of non-payment of electricity bills. The Substation will be the receiving end. The data received is fed to a microcontroller at the Substation which will automatically calculate the bill based on tariff provider and display it.

  2. 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.

  3. A direct digital controller for an automatic sodium plugging meter

    International Nuclear Information System (INIS)

    Tobias, A.

    1977-07-01

    A plugging meter is a device for monitoring the impurity level of liquid sodium. It is used to measure the temperature at which an impurity precipitates or re-dissolves at a restricting orifice. The concentration of the impurity may be then deduced from known solubility/temperature relationships. A software controller for a sodium plugging meter has been implemented on a PDP-11 using SWEPSPEED. The algorithm used to perform both flow and temperature control functions is based on a modified standard three-term controller. Both design and operation of the controller are described. The functions which may be performed by the controller are: (i) maintain a steady temperature at the restricting orifice, (ii) perform a temperature ramp at a rate defined by the operator, and (iii) maintain a partial plug of impurities at the orifice by appropriate manipulation of the temperature. Accuracies so far achieved are approximately +- 5% for flow control and better that +- 1 0 C for temperature control. (author)

  4. Transit Timing Observations from Kepler: II. Confirmation of Two Multiplanet Systems via a Non-parametric Correlation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B.; /Florida U.; Fabrycky, Daniel C.; /Lick Observ.; Steffen, Jason H.; /Fermilab; 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; Moorhead, Althea V.; /Florida U.; Morehead, Robert C.; /Florida U.; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames /SETI Inst., Mtn. View /San Diego State U., Astron. Dept.

    2012-01-01

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies are in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the transit timing variations of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  5. Sham Feeding with Bacon Does Not Alter Transit Time or Complete Examination Rate During Small Bowel Capsule Endoscopy.

    Science.gov (United States)

    Prichard, David; Ou, George; Galorport, Cherry; Enns, Robert

    2018-02-01

    During capsule endoscopy (CE) studies, the complete examination rate (CER) can be increased by prolonging capsule battery life or reducing gastric transit time (GTT) and/or small bowel transit time (SBTT). However, despite enhanced battery life, 10% of studies remain incomplete. Previously studied interventions to reduce SBTT and enhance CER have produced conflicting results. We hypothesize that this may be a consequence of an insufficiently potent stimulus of small bowel motility. To examine whether potent stimulation of the cephalic response of digestion during small bowel CE reduces GTT and/or SBTT and thus increases the CER. A single-blind randomized trial was performed to evaluate the effect of bacon sham feeding on GTT, SBTT and CER. Baseline characteristics were similar between 63 sham fed patients and 59 controls. The median GTT was 17 min (9-65) in the bacon group and 25 min (14-55) in the control group. The median SBTT was 199 min (119-316) and 222 min (151-287), respectively. Cox proportional hazards model demonstrated no significant difference between groups for GTT (rate ratio 1.03, 95% CI 0.71-1.51, P = 0.87) or SBTT (rate ratio 1.02, 95% CI 0.70-1.49, P = 0.93). Although the taste of bacon was considered favorably by 72% of participants, taste did not correlate with GTT (ρ = 0.03, P = 0.83) or SBTT (ρ = - 0.115, P = 0.33). The CER was 91 and 95% in the bacon and control groups, respectively (P = 0.35). Bacon sham feeding has no effect on GTT, SBTT or CER and cannot be recommended in clinical practice.

  6. Age and transit time distributions of carbon in a nonlinear global model perturbed by nonautonomous fossil-fuel emissions signals

    Science.gov (United States)

    Metzler, Holger; Müller, Markus; Sierra, Carlos A.

    2017-04-01

    Carbon fluxes in the ocean-atmosphere-biosphere system are governed by nonlinear processes, which are usually modeled by a system of ordinary differential equations. It is very difficult to analyze such nonlinear models and to predict their future behavior, particularly their internal age structure: How old is the carbon in different pools (ages) and how old is the carbon that leaves the system (transit times)? How is this age structure modified by the addition of fossil fuel emissions? To answer these questions, we developed a new mathematical approach that allows us to compute and visualize the age structure of models of well mixed pools even if they are nonlinear and nonautonomous. We do not only consider mean ages and mean transit times, but entire distributions. Consequently, we can consider important statistics such as the median, quantiles, or the variance. We applied this mathematical approach to a nonlinear global carbon model consisting of three pools (atmosphere, surface ocean, and terrestrial biosphere) and driven by four emission scenarios (RCP3-PD, RCP4.5, RCP6, RCP8.5). Results showed that the addition of fossil fuels modifies the age structure of C in the atmosphere by drastically increasing its proportion of young carbon. We found little differences among predicted mean ages for the four emission scenarios, but changes in the overall distributions were large with effects on median, quantiles and variance. In the short-term, fossil-fuel emissions have an important effect on the amount of carbon that is exchanged among Earth's main C reservoirs. In the long-term, most added C will eventually end up in the deep ocean, but the time required to return to pre-industrial C age distributions is largely dependent on emission scenarios.

  7. Household Classification Using Smart Meter Data

    Directory of Open Access Journals (Sweden)

    Carroll Paula

    2018-03-01

    Full Text Available This article describes a project conducted in conjunction with the Central Statistics Office of Ireland in response to a planned national rollout of smart electricity metering in Ireland. We investigate how this new data source might be used for the purpose of official statistics production. This study specifically looks at the question of determining household composition from electricity smart meter data using both Neural Networks (a supervised machine learning approach and Elastic Net Logistic regression. An overview of both classification techniques is given. Results for both approaches are presented with analysis. We find that the smart meter data alone is limited in its capability to distinguish between household categories but that it does provide some useful insights.

  8. Implementation plan for smart meters in Ontario

    International Nuclear Information System (INIS)

    2004-01-01

    This paper presents Ontario Energy Board's implementation plan to install 800,000 smart meters by December 31, 2007. The objective is to help consumers control their electricity bills through conservation and demand response. The three conditions that will change power consumption habits are price changes in response to demand and supply forces; the ability of consumers to see and respond to the price signals; and, a measurement of the response so that consumers get credit for their actions. This paper identifies the mandatory technical requirements for smart meters and the support operations of distributors. It sets priorities, identifies barriers and regulatory mechanisms for cost recovery. It also discusses options for ownership of the meters. 18 refs., 1 tab., 2 figs

  9. IMPORTANT: Fluke is recalling Digital Clamp Meters

    CERN Multimedia

    2013-01-01

    Fluke is voluntarily recalling four models of Digital Clamp Meters: Fluke 373, 374, 375 and 376. If you own one of these clamp meters, please stop using it and send it back to Fluke for repair even if you have not experienced problems.   Description of the problem: "The printed circuit assembly may not be properly fastened to the test lead input jack. This may result in inaccurate voltage readings, including a low or no-voltage reading on a circuit energised with a hazardous voltage, presenting a shock, electrocution or thermal burn hazard." To determine if your clamp meter is affected by this recall notice, and for more information, click here.

  10. Simple meters get smart? Cost benefit analysis of smart metering infrastructure

    International Nuclear Information System (INIS)

    Van Gerwen, R.J.F.; Jaarsma, S.A.; Koenis, F.T.C.

    2005-08-01

    The Dutch Ministry of Economic Affairs requested a cost-benefit analysis of the large scale introduction of a smart meter infrastructure for gas and electricity consumption by small consumers. The questions asked in the study need to be answered in order to enable a well-founded evaluation of the implementation of smart meters. [mk] [nl

  11. Privacy friendly aggregation of smart meter readings, even when meters crash

    NARCIS (Netherlands)

    Hoepman, J.H.

    2017-01-01

    A well studied privacy problem in the area of smart grids is the question of how to aggregate the sum of a set of smart meter readings in a privacy friendly manner, i.e., in such a way that individual meter readings are not revealed to the adversary. Much less well studied is how to deal with

  12. Design and construction of portable survey meter

    Science.gov (United States)

    Singseeta, W.; Thong-aram, D.; Pencharee, S.

    2017-09-01

    This work was aimed to design and construction of portable survey meter for radiation dose measuring. The designed system consists of 4 main parts consisting of low voltage power supply, radiation detection, radiation measurement and data display part on android phone. The test results show that the ripple voltage of low voltage power supply is less than 1%, the maximum integral counts are found to be 104 counts per second and the maximum distance of wireless commination between the server and the client is about 10 meter. It was found that the developed system had small size and light weight for portable instrument.

  13. Development and Testing of Infrared Water Current Meter | Ezenne ...

    African Journals Online (AJOL)

    The digital water current meter with infrared display velocity readings obtained per second. To confirm the accuracy of the infrared current meter, it was tested alongside with a conventional water current meter. The measurements performed with the infrared current meter compared well with the measurement performed with ...

  14. A Probabilistic Model of Meter Perception: Simulating Enculturation

    NARCIS (Netherlands)

    van der Weij, B.; Pearce, M.T.; Honing, H.

    Enculturation is known to shape the perception of meter in music but this is not explicitly accounted for by current cognitive models of meter perception. We hypothesize that the induction of meter is a result of predictive coding: interpreting onsets in a rhythm relative to a periodic meter

  15. 49 CFR 192.353 - Customer meters and regulators: Location.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Customer meters and regulators: Location. 192.353... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.353 Customer meters and regulators: Location. (a) Each meter and service...

  16. The effects of capillary transit time heterogeneity (CTH on the cerebral uptake of glucose and glucose analogs:Application to FDG and comparison to oxygen uptake.

    Directory of Open Access Journals (Sweden)

    Hugo Angleys

    2016-10-01

    Full Text Available Glucose is the brain’s principal source of ATP, but the extent to which cerebral glucose consumption (CMRglc is coupled with its oxygen consumption (CMRO2 remains unclear. Measurements of the brain’s oxygen-glucose index OGI=CMRO2/CMRglc suggest that its oxygen uptake largely suffices for oxidative phosphorylation. Nevertheless, during functional activation and in some disease states, brain tissue seemingly produces lactate although cerebral blood flow (CBF delivers sufficient oxygen, so-called aerobic glycolysis. OGI measurements, in turn, are method-dependent in that estimates based on glucose analog uptake depend on the so-called lumped constant (LC to arrive at CMRglc. Capillary transit time heterogeneity (CTH, which is believed to change during functional activation and some disease states, affects the extraction efficacy of oxygen from blood. We developed a three-compartment model of glucose extraction to examine whether CTH also affects glucose extraction into brain tissue. We then combined this model with our previous model of oxygen extraction to examine whether differential glucose and oxygen extraction might favor nonoxidative glucose metabolism under certain conditions. Our model predicts that glucose uptake is largely unaffected by changes in its plasma concentration, while changes in CBF and CTH affect glucose and oxygen uptake to different extents. Accordingly, functional hyperemia facilitates glucose uptake more than oxygen uptake, favoring aerobic glycolysis during enhanced energy demands. Applying our model to glucose analogs, we observe that LC depends on physiological state, with a risk of overestimating relative increases in CMRglc during functional activation by as much as 50%.

  17. Development of quick-response area-averaged void fraction meter. Application to BWR condition

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tadashi; Watanabe, Hironori; Kimura, Mamoru; Anoda, Yoshinari [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-05-01

    Authors have been developed a practical conductance-type void fraction meter to measure instantaneously area-averaged void fraction in rod bundle. The principle of the meter is based on the fact that the electrical conductance changes with the change of void fraction in gas-liquid two-phase flow. According to air/water two-phase flow experiment, the void fraction was approximated by {alpha}=1-I/I{sub 0}, where {alpha} and I are void fraction and current (I{sub 0} is current at {alpha}=0). Authors investigated the performance of the void fraction meter under high temperature/high pressure conditions (BWR condition; 290degC, 7MPa). The results indicated that the void fraction was approximated by {alpha}=1-I/I{sub 0} even under high temperature/high pressure condition of stem/water flow. However, it is necessary to take account of temperature dependency of water specific conductance. Therefore, authors derived a correction equation for temperature dependency. Further, for applying the void fraction meter to a large-scale facility, it was found to be necessary to reduce the capacitance of the circuit. Then, authors developed the method to reduce the capacitance effect. Finally, authors succeeded to measure the void fraction in 2 x 2 bundle flow path at the range of 0% - 70% in the error of 10% under high temperature/high pressure and mass flux of less than 133 kg/m{sup 2}s. Developed void fraction meter is theoretically not affected by flow rate. Therefore, it can be applied to the condition of oscillating flow. (author)

  18. Smart meters and economies in energy use

    International Nuclear Information System (INIS)

    Zelem, Marie-Christine

    2014-01-01

    A central theme promoted by the government for the energy transition, the mastering of energy consumption features notably the setting up of intelligent electricity networks and the installation of what are known as smart meters. Yet will consumers actually be in a position to become proponents of more sober use of energy? (author)

  19. Smart wavelength meter for integrated photonics

    NARCIS (Netherlands)

    Benelajla, Meryem; Taballione, Caterina; Boller, Klaus J.

    2017-01-01

    Thermally tunable SiN waveguide microring resonators in connection with neural network readout algorithms appear promising for use as integrated optical wavelength meters. So far, we have observed long-term reliability and a temperature immunity of the readout across several degrees of ambient

  20. Field test of coordinated ramp metering (CRM).

    Science.gov (United States)

    2017-03-15

    This project has focused on field implementation and testing of a Coordinated Ramp Metering (CRM) algorithm at California State Route 99 : Northbound corridor in Sacramento between Calvine Road and the SR50 interchange after 12th Ave. It is a 9 mile ...

  1. Weak measurements with a qubit meter

    DEFF Research Database (Denmark)

    Wu, Shengjun; Mølmer, Klaus

    2009-01-01

    We derive schemes to measure the so-called weak values of quantum system observables by coupling of the system to a qubit meter system. We highlight, in particular, the meaning of the imaginary part of the weak values, and show how it can be measured directly on equal footing with the real part...

  2. Optical system for a universal luminance meter

    NARCIS (Netherlands)

    Schreuder, D.A.

    1965-01-01

    There is a need for luminance meters in various fields of photometry having these characteristics: a- objective method of measurements. b. variable shape and size of measurement area. c- absence of parallax during aiming operations. d- Possibility of observing the part of the field of view to be

  3. Revealing household characteristics from smart meter data

    International Nuclear Information System (INIS)

    Beckel, Christian; Sadamori, Leyna; Staake, Thorsten; Santini, Silvia

    2014-01-01

    Utilities are currently deploying smart electricity meters in millions of households worldwide to collect fine-grained electricity consumption data. We present an approach to automatically analyzing this data to enable personalized and scalable energy efficiency programs for private households. In particular, we develop and evaluate a system that uses supervised machine learning techniques to automatically estimate specific “characteristics” of a household from its electricity consumption. The characteristics are related to a household's socio-economic status, its dwelling, or its appliance stock. We evaluate our approach by analyzing smart meter data collected from 4232 households in Ireland at a 30-min granularity over a period of 1.5 years. Our analysis shows that revealing characteristics from smart meter data is feasible, as our method achieves an accuracy of more than 70% over all households for many of the characteristics and even exceeds 80% for some of the characteristics. The findings are applicable to all smart metering systems without making changes to the measurement infrastructure. The inferred knowledge paves the way for targeted energy efficiency programs and other services that benefit from improved customer insights. On the basis of these promising results, the paper discusses the potential for utilities as well as policy and privacy implications. - Highlights: • Many household characteristics can be automatically inferred from smart meter data. • We develop a system to infer employment status and number of occupants, for instance. • We evaluate our system analyzing data collected from 4232 households in Ireland. • The insights enable personalized and scalable efficiency campaigns for utilities. • Energy efficiency measures must be complemented by privacy protection

  4. Experiment of aerosol-release time for a novel automatic metered dose inhaler

    Directory of Open Access Journals (Sweden)

    Mingrong Zhang

    2016-05-01

    Full Text Available The objective of this study was to evaluate the aerosol-release time in the development of a new automatic adapter for metered dose inhaler. With this device, regular manually operated metered dose inhalers become automatic. During the study, an inhalation simulator was designed and tested with the newly developed mechatronic system. By adjusting the volume and the pressure of the vacuum tank, most human inhalation waveforms were able to simulate. As an example, regular quick-deep and slow-deep waveforms were matched within reasonable accuracy. Finally, with the help of dynamic image processing, the aerosol-release time (Tr was carefully measured and fully discussed, including the switch-on time (Ts, the mechatronics-hysteresis (Tm and the intentional-delay (Ti. Under slow-deep inhalation condition which is suitable for metered dose inhaler medicine delivery, the switch-on flow-rate could reach as low as 10 L/min, and the corresponding switch-on time was approximately 0.20 s. While the mechatronics-hysteresis depended on the brand of metered dose inhaler, assuming there was no intentional-delay, the aerosol-release time could be as low as 0.40 and 0.60 s, respectively, for two commercially available metered dose inhalers studied in this article. Therefore, this newly developed mechatronic adapter system could ensure aerosol-release time (Tr within satisfactory range for metered dose inhalers.

  5. A tool to increase information-processing capacity for consumer water meter data

    Directory of Open Access Journals (Sweden)

    Heinz E. Jacobs

    2012-06-01

    Objective: The objective of this research article was to describe the development of Swift, a locally developed software tool for analysing water meter data from an information management perspective, which engineers in the water field generally use, and to assess critically the influence of Swift on published research and industry. This article focuses on water usage and the challenge of data interchange and extraction as issues that various industries face. Method: This article presents the first detailed report on Swift. It uses a detailed knowledge review and presents and summarises the findings chronologically. Results: The water meter data flow path used to be quite simple. The risk of breaches in confidentiality was limited. Technological advances over the years have led to additional knowledge coming from the same water meter readings with subsequent research outputs. However, there are also complicated data flow paths and increased risks. Users have used Swift to analyse more than two million consumers’ water meter readings to date. Studies have culminated in 10 peer-reviewed journal articles using the data. Seven of them were in the last five years. Conclusion: Swift-based data was the basis of various research studies in the past decade. Practical guidelines in the civil engineering fraternity for estimating water use in South Africa have incorporated knowledge from these studies. Developments after 1995 have increased the information processing capacity for water meter data.

  6. A tool to increase information-processing capacity for consumer water meter data

    Directory of Open Access Journals (Sweden)

    Heinz E. Jacobs

    2012-02-01

    Full Text Available Background: Water service providers invoice most South African urban consumers for the water they use every month. A secure treasury system generates water invoices at municipalities’ financial departments. Information about the water usage of customers initially comes from reading the water meters, usually located in gardens near the front boundaries of properties. Until as recently as 1990, the main purpose of the water meter readings was to generate invoices for water usage. There are various treasury systems for this purpose.Objective: The objective of this research article was to describe the development of Swift, a locally developed software tool for analysing water meter data from an information management perspective, which engineers in the water field generally use, and to assess critically the influence of Swift on published research and industry. This article focuses on water usage and the challenge of data interchange and extraction as issues that various industries face.Method: This article presents the first detailed report on Swift. It uses a detailed knowledge review and presents and summarises the findings chronologically.Results: The water meter data flow path used to be quite simple. The risk of breaches in confidentiality was limited. Technological advances over the years have led to additional knowledge coming from the same water meter readings with subsequent research outputs. However, there are also complicated data flow paths and increased risks. Users have used Swift to analyse more than two million consumers’ water meter readings to date. Studies have culminated in 10 peer-reviewed journal articles using the data. Seven of them were in the last five years.Conclusion: Swift-based data was the basis of various research studies in the past decade. Practical guidelines in the civil engineering fraternity for estimating water use in South Africa have incorporated knowledge from these studies. Developments after 1995 have

  7. Long-term effects of lipase inhibition by orlistat on gastric emptying and orocecal transit time of a solid meal.

    Science.gov (United States)

    Kocełak, Piotr; Zahorska-Markiewicz, Barbara; Jonderko, Krzysztof; Olszanecka-Glinianowicz, Magdalena; Zak-Gołab, Agnieszka; Holecki, Michał; Kamińska, Magdalena; Szymszal, Małgorzata

    2008-01-01

    We assessed the impact of a prolonged lipase inhibition upon gastric emptying (GE) and orocecal transit time (OCTT) of a 355-kcal low-fat solid meal. In double-blind manner, 40 obese women BMI > 30 kg/m2, randomly allocated into two equal groups, took orally t.i.d. 120 mg orlistat or placebo during 8 weeks of a weight-reducing management. At randomization and after 2 months, GE was measured simultaneously with OCTT by means of a 13C-octanoic acid and a hydrogen breath test, respectively. Lipolytic activity was evaluated with a 13C-mixed triglyceride breath test (13C-MTGBT). A profound lipase inhibition by orlistat was confirmed by a 79.5% +/- 16.9% reduction of the cumulative 6-h 13C recovery with 13CMTGBT. GE remained unchanged either in the orlistat (T1/2, 188 +/- 35 min start versus 198 +/- 36 min end) or the placebo (T1/2, 191 +/- 35 min start versus 180 +/- 39 min end) group. OCTT increased from 208 +/- 54 min to 271 +/- 64 min (P orlistat treatment and did not change significantly (216 +/- 76 vs. 234 +/- 72 min) in the placebo group. No adverse effect on the GE and a moderate prolongation of the OCTT of a low-fat solid meal is to be expected under a prolonged treatment with orlistat at a typical dosage regimen.

  8. 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.

  9. Validation of New and Existing Decision Rules for the Estimation of Beat-to-Beat Pulse Transit Time

    Directory of Open Access Journals (Sweden)

    Xiaolin Zhou

    2015-01-01

    Full Text Available Pulse transit time (PTT is a pivotal marker of vascular stiffness. Because the actual PTT duration in vivo is unknown and the complicated variation in waveform may occur, the robust determination of characteristic point is still a very difficult task in the PTT estimation. Our objective is to devise a method for real-time estimation of PTT duration in pulse wave. It has an ability to reduce the interference caused by both high- and low-frequency noise. The reproducibility and performance of these methods are assessed on both artificial and clinical pulse data. Artificial data are generated to investigate the reproducibility with various signal-to-noise ratios. For all artificial data, the mean biases obtained from all methods are less than 1 ms; collectively, this newly proposed method has minimum standard deviation (SD, <1 ms. A set of data from 33 participants together with the synchronously recorded continuous blood pressure data are used to investigate the correlation coefficient (CC. The statistical analysis shows that our method has maximum values of mean CC (0.5231, sum of CCs (17.26, and median CC (0.5695 and has the minimum SD of CCs (0.1943. Overall, the test results in this study indicate that the newly developed method has advantages over traditional decision rules for the PTT measurement.

  10. Importance of interactions between food quality, quantity, and gut transit time on consumer feeding, growth, and trophic dynamics.

    Science.gov (United States)

    Mitra, Aditee; Flynn, Kevin J

    2007-05-01

    Ingestion kinetics of animals are controlled by both external food availability and feedback from the quantity of material already within the gut. The latter varies with gut transit time (GTT) and digestion of the food. Ingestion, assimilation efficiency, and thus, growth dynamics are not related in a simple fashion. For the first time, the important linkage between these processes and GTT is demonstrated; this is achieved using a biomass-based, mechanistic multinutrient model fitted to experimental data for zooplankton growth dynamics when presented with food items of varying quality (stoichiometric composition) or quantity. The results show that trophic transfer dynamics will vary greatly between the extremes of feeding on low-quantity/high-quality versus high-quantity/low-quality food; these conditions are likely to occur in nature. Descriptions of consumer behavior that assume a constant relationship between the kinetics of grazing and growth irrespective of food quality and/or quantity, with little or no recognition of the combined importance of these factors on consumer behavior, may seriously misrepresent consumer activity in dynamic situations.

  11. 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.

  12. Mean transit times and the sites of synthesis and catabolism of tissue plasminogen activator and plasminogen activator inhibitor type 1 in young subjects

    DEFF Research Database (Denmark)

    Jørgensen, M; Petersen, K.R.; Vinberg, N

    2001-01-01

    Using an invasive technique, we studied the mean transit time, the net quantitative turnover rate, and the sites of synthesis and catabolism of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) in healthy young volunteers in the fasting, steady state. Blood....../min, respectively. The extraction fraction and the mean transit time in the splanchnic circulation were, respectively, 0.63 and 5.6 min for active t-PA and 0.17 and 21 min for t-PA antigen. Active PAI-1 was synthesized in the splanchnic circulation at a rate of 890 IU/min and had a mean transit time of about 9...

  13. Gastric emptying rate and small bowel transit time in patients with irritable bowel syndrome determined with 99mTc-labeled pellets and scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, O.H.; Gjorup, T.; Christensen, F.N.

    1986-12-01

    A new method employing 99mTc-labeled pellets for determination of the gastric emptying rate and small bowel transit time is described. The participants were six normal subjects and 16 patients with irritable bowel syndrome (eight with diarrhea and eight with obstipation as the primary complaint). The gastric emptying rate was the same in the three groups. The patients in the obstipation group had a significantly longer small bowel transit time than the normals (P less than 0.02) and the patients in the diarrhea group (P less than 0.01). There was no demonstrable difference between the small bowel transit time in the normals and in the patients in the diarrhea group.

  14. Gastric emptying rate and small bowel transit time in patients with irritable bowel syndrome determined with 99mTc-labeled pellets and scintigraphy

    International Nuclear Information System (INIS)

    Nielsen, O.H.; Gjorup, T.; Christensen, F.N.

    1986-01-01

    A new method employing 99mTc-labeled pellets for determination of the gastric emptying rate and small bowel transit time is described. The participants were six normal subjects and 16 patients with irritable bowel syndrome (eight with diarrhea and eight with obstipation as the primary complaint). The gastric emptying rate was the same in the three groups. The patients in the obstipation group had a significantly longer small bowel transit time than the normals (P less than 0.02) and the patients in the diarrhea group (P less than 0.01). There was no demonstrable difference between the small bowel transit time in the normals and in the patients in the diarrhea group

  15. Calibration of reference KAP-meters at SSDL and cross calibration of clinical KAP-meters

    International Nuclear Information System (INIS)

    Hetland, Per O.; Friberg, Eva G.; Oevreboe, Kirsti M.; Bjerke, Hans H.

    2009-01-01

    In the summer of 2007 the secondary standard dosimetry laboratory (SSDL) in Norway established a calibration service for reference air-kerma product meter (KAP-meter). The air-kerma area product, PKA, is a dosimetric quantity that can be directly related to the patient dose and used for risk assessment associated with different x-ray examinations. The calibration of reference KAP-meters at the SSDL gives important information on parameters influencing the calibration factor for different types of KAP-meters. The use of reference KAP-meters calibrated at the SSDL is an easy and reliable way to calibrate or verify the PKA indicated by the x-ray equipment out in the clinics. Material and methods. Twelve KAP-meters were calibrated at the SSDL by use of the substitution method at five diagnostic radiation qualities (RQRs). Results. The calibration factors varied from 0.94 to 1.18. The energy response of the individual KAP-meters varied by a total of 20% between the different RQRs and the typical chamber transmission factors ranged from 0.78 to 0.91. Discussion. It is important to use a calibrated reference KAP-meter and a harmonised calibration method in the PKA calibration in hospitals. The obtained uncertainty in the PKA readings is comparable with other calibration methods if the information in the calibration certificate is correct used, corrections are made and proper positioning of the KAP-chamber is performed. This will ensure a reliable estimate of the patient dose and a proper optimisation of conventional x-ray examinations and interventional procedures

  16. Metering error quantification under voltage and current waveform distortion

    Science.gov (United States)

    Wang, Tao; Wang, Jia; Xie, Zhi; Zhang, Ran

    2017-09-01

    With integration of more and more renewable energies and distortion loads into power grid, the voltage and current waveform distortion results in metering error in the smart meters. Because of the negative effects on the metering accuracy and fairness, it is an important subject to study energy metering combined error. In this paper, after the comparing between metering theoretical value and real recorded value under different meter modes for linear and nonlinear loads, a quantification method of metering mode error is proposed under waveform distortion. Based on the metering and time-division multiplier principles, a quantification method of metering accuracy error is proposed also. Analyzing the mode error and accuracy error, a comprehensive error analysis method is presented which is suitable for new energy and nonlinear loads. The proposed method has been proved by simulation.

  17. 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.

  18. Contrasting transit times of water from peatlands and eucalypt forests in the Australian Alps determined by tritium: implications for vulnerability and the source of water in upland catchments

    Science.gov (United States)

    Cartwright, Ian; Morgenstern, Uwe

    2016-12-01

    Peatlands are a distinctive and important component of many upland regions that commonly contain distinctive flora and fauna which are different from those of adjacent forests and grasslands. Peatlands also represent a significant long-term store of organic carbon. While their environmental importance has long since been recognised, water transit times within peatlands are not well understood. This study uses tritium (3H) to estimate the mean transit times of water from peatlands and from adjacent gullies that contain eucalypt forests in the Victorian Alps (Australia). The 3H activities of the peatland water range from 2.7 to 3.3 tritium units (TUs), which overlap the measured (2.9 to 3.0 TU) and expected (2.8 to 3.2 TU) average 3H activities of rainfall in this region. Even accounting for seasonal recharge by rainfall with higher 3H activities, the mean transit times of the peatland waters are < 6.5 years and may be less than 2 years. Water from adjacent eucalypt forest streams has 3H activities of 1.6 to 2.1 TU, implying much longer mean transit times of 5 to 29 years. Cation / Cl and Si / Cl ratios are higher in the eucalypt forest streams than the peatland waters and both of these water stores have higher cation / Cl and Si / Cl ratios than rainfall. The major ion geochemistry reflects the degree of silicate weathering in these catchments that is controlled by both transit times and aquifer lithology. The short transit times imply that, unlike the eucalypt forests, the peatlands do not represent a long-lived store of water for the local river systems. Additionally, the peatlands are susceptible to drying out during drought, which renders them vulnerable to damage by the periodic bushfires that occur in this region.

  19. Critical Review of Directional Neutron Survey Meters

    International Nuclear Information System (INIS)

    Balmer, M.J.I.; Gamage, K.A.A.; Taylor, G.C.

    2013-06-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument. (authors)

  20. Gamin partable radiation meter with alarm threshold

    International Nuclear Information System (INIS)

    Payat, Rene.

    1981-10-01

    The Gamin Radiation meter is a direct reading, portable, battery-powered gamma doserate meter featuring alarm thresholds. Doserate is read on a micro-ammeter with a millirad-per-hour logarithmic scale, covering a range of 0,1 to 1000 millirads/hour. The instrument issues an audible warning signal when dose-rate level exceeds a threshold value, which can be selected. The detector tube is of the Geiger-Muller counter, energy compensated type. Because of its low battery drain, the instrument can be operated continously for 1000 hours. It is powered by four 1.5 volt alcaline batteries of the R6 type. The electronic circuitry is housed in a small lightweight case made of impact resistant plastic. Applications of the Gamin portable radiation monitor are found in health physics, safety departments, medical facilities, teaching, civil defense [fr

  1. Smart data acquisition system for utilities metering

    Science.gov (United States)

    Ileana, I.; Risteiu, M.; Tulbure, A.; Rusu, M.

    2009-01-01

    The paper approaches the task of automatically reading and recognition of registered data on the utility meters of the users and is a part of a more complex project of our team concerning the remote data acquisition from industrial processes. A huge amount of utility meters in our country is of mechanical type without remote acquiring facilities and as an intermediate solution we propose an intelligent optical acquisition system which will store the read values in desktop and mobile devices. The main requirements of such a system are: portability, data reading accuracy, fast processing and energy independence. The paper analyses several solutions (including Artificial Neural Networks approach) tested by our team and present the experimental results and our conclusions.

  2. This is the size of one meter

    DEFF Research Database (Denmark)

    Davidsen, Jacob; Ryberg, Thomas

    2017-01-01

    In CSCL studies, language is often foregrounded as the primary resource for engaging in collaborative learning, while the body is more often positioned as a secondary resource. There is, however, a growing interest in the body as a resource in learning and collaboration in and outside CSCL......, the pair engages in a discussion regarding the size of one meter through language, gestures and manipulation of the material resources. The analysis shows two distinct ways of understanding the length of one meter, which primarily are visible through the children’s gestures and bodily movements....... In the analysis we show how the children dynamically produce body-material resources for communicative and illustrative purposes; moreover, they use body-material resources as a cognitive tool and as a way of shepherding each other. The study forms part of a body of studies analysing and theorizing the body...

  3. Critical review of directional neutron survey meters

    Science.gov (United States)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2014-01-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument.

  4. Evaluation of a metering, mixing, and dispensing system for mixing polysulfide adhesive

    Science.gov (United States)

    Evans, Kurt B.

    1989-01-01

    Tests were performed to evaluate whether a metered mixing system can mix PR-1221 polysulfide adhesive as well as or better than batch-mixed adhesive; also, to evaluate the quality of meter-mixed PR-1860 and PS-875 polysulfide adhesives. These adhesives are candidate replacements for PR-1221 which will not be manufactured in the future. The following material properties were evaluated: peel strength, specific gravity and adhesive components of mixed adhesives, Shore A hardness, tensile adhesion strength, and flow rate. Finally, a visual test called the butterfly test was performed to observe for bubbles and unmixed adhesive. The results of these tests are reported and discussed.

  5. Assessing liner performance using on-farm milk meters.

    Science.gov (United States)

    Penry, J F; Leonardi, S; Upton, J; Thompson, P D; Reinemann, D J

    2016-08-01

    The primary objective of this study was to quantify and compare the interactive effects of liner compression, milking vacuum level, and pulsation settings on average milk flow rates for liners representing the range of liner compression of commercial liners. A secondary objective was to evaluate a methodology for assessing liner performance that can be applied on commercial dairy farms. Eight different liner types were assessed using 9 different combinations of milking system vacuum and pulsation settings applied to a herd of 80 cows with vacuum and pulsation conditions changed daily for 36d using a central composite experimental design. Liner response surfaces were created for explanatory variables milking system vacuum (Vsystem) and pulsator ratio (PR) and response variable average milk flow rate (AMF=total yield/total cups-on time) expressed as a fraction of the within-cow average flow rate for all treatments (average milk flow rate fraction, AMFf). Response surfaces were also created for between-liner comparisons for standardized conditions of claw vacuum and milk ratio (fraction of pulsation cycle during which milk is flowing). The highest AMFf was observed at the highest levels of Vsystem, PR, and overpressure. All liners showed an increase in AMF as milking conditions were changed from low to high standardized conditions of claw vacuum and milk ratio. Differences in AMF between liners were smallest at the most gentle milking conditions (low Vsystem and low milk ratio), and these between-liner differences in AMF increased as liner overpressure increased. Differences were noted with vacuum drop between Vsystem and claw vacuum depending on the liner venting system, with short milk tube vented liners having the greater vacuum drop than mouthpiece chamber vented liners. The accuracy of liner performance assessment in commercial parlors fitted with milk meters can be improved by using a central composite experimental design with a repeated center point treatment

  6. From Smart Metering to Smart Grid

    Science.gov (United States)

    Kukuča, Peter; Chrapčiak, Igor

    2016-06-01

    The paper deals with evaluation of measurements in electrical distribution systems aimed at better use of data provided by Smart Metering systems. The influence of individual components of apparent power on the power loss is calculated and results of measurements under real conditions are presented. The significance of difference between the traditional and the complex evaluation of the electricity consumption efficiency by means of different definitions of the power factor is illustrated.

  7. Electricity Consumption Clustering Using Smart Meter Data

    Directory of Open Access Journals (Sweden)

    Alexander Tureczek

    2018-04-01

    Full Text Available Electricity smart meter consumption data is enabling utilities to analyze consumption information at unprecedented granularity. Much focus has been directed towards consumption clustering for diversifying tariffs; through modern clustering methods, cluster analyses have been performed. However, the clusters developed exhibit a large variation with resulting shadow clusters, making it impossible to truly identify the individual clusters. Using clearly defined dwelling types, this paper will present methods to improve clustering by harvesting inherent structure from the smart meter data. This paper clusters domestic electricity consumption using smart meter data from the Danish city of Esbjerg. Methods from time series analysis and wavelets are applied to enable the K-Means clustering method to account for autocorrelation in data and thereby improve the clustering performance. The results show the importance of data knowledge and we identify sub-clusters of consumption within the dwelling types and enable K-Means to produce satisfactory clustering by accounting for a temporal component. Furthermore our study shows that careful preprocessing of the data to account for intrinsic structure enables better clustering performance by the K-Means method.

  8. Topical Metered-dosing Dispenser Performance Evaluation.

    Science.gov (United States)

    Liu, Qiang; Kupiec, Thomas C; Vu, Nicole T

    2016-01-01

    Topical metered-dosing dispensers are designed for dosing accuracy and ease-of-use by the patients while protecting the packaged products from environmental exposure and contamination. The objective of this study was to evaluate the accuracy, precision, and residual of available topical metered-dosing dispensers with different types of topical cream for practical application. Triplicate samples of five different dispensers were tested. This test was completed using three types of commercial topical cream-bases of dissimilar Total Active Pharmaceutical Ingredient Load Percentages, Transdermal Penetration Percentages, and Specific Gravities. The dispensers were evaluated according to specified dose-uniformity criteria for a total dispensing capacity of 30 mL at 0.5 mL per dose for 60 doses. The study shows Topi-CLICK performed with the best precision and accuracy of dosing in comparison to the airless-pump type dispensers. While the dispensing was highly variable with airless pumps and may require calibration for each packaged product, remarkably the performance of Topi-CLICK was not affected by different types of cream-bases and does not require additional metering calibration. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  9. Route Optimization for Offloading Congested Meter Fixes

    Science.gov (United States)

    Xue, Min; Zelinski, Shannon

    2016-01-01

    The Optimized Route Capability (ORC) concept proposed by the FAA facilitates traffic managers to identify and resolve arrival flight delays caused by bottlenecks formed at arrival meter fixes when there exists imbalance between arrival fixes and runways. ORC makes use of the prediction capability of existing automation tools, monitors the traffic delays based on these predictions, and searches the best reroutes upstream of the meter fixes based on the predictions and estimated arrival schedules when delays are over a predefined threshold. Initial implementation and evaluation of the ORC concept considered only reroutes available at the time arrival congestion was first predicted. This work extends previous work by introducing an additional dimension in reroute options such that ORC can find the best time to reroute and overcome the 'firstcome- first-reroute' phenomenon. To deal with the enlarged reroute solution space, a genetic algorithm was developed to solve this problem. Experiments were conducted using the same traffic scenario used in previous work, when an arrival rush was created for one of the four arrival meter fixes at George Bush Intercontinental Houston Airport. Results showed the new approach further improved delay savings. The suggested route changes from the new approach were on average 30 minutes later than those using other approaches, and fewer numbers of reroutes were required. Fewer numbers of reroutes reduce operational complexity and later reroutes help decision makers deal with uncertain situations.

  10. Critical review of directional neutron survey meters

    International Nuclear Information System (INIS)

    Balmer, Matthew J.I.; Gamage, Kelum A.A.; Taylor, Graeme C.

    2014-01-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument. -- Highlights: • We critically review the existing literature into directional survey meters. • Instruments which could be adapted for this purpose are also reviewed. • Investigate the potential of much lighter portable real-time instrument. • Improvements to existing instruments are suggested to improve their design. • Boron-Doped liquid scintillator design is the most promising, but needs further work

  11. Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge measurements

    Science.gov (United States)

    Mwashote, B.M.; Burnett, W.C.; Chanton, J.; Santos, I.R.; Dimova, N.; Swarzenski, P.W.

    2010-01-01

    Submarine groundwater discharge (SGD) assessments were conducted both in the laboratory and at a field site in the northeastern Gulf of Mexico, using a continuous heat-type automated seepage meter (seepmeter). The functioning of the seepmeter is based on measurements of a temperature gradient in the water between downstream and upstream positions in its flow pipe. The device has the potential of providing long-term, high-resolution measurements of SGD. Using a simple inexpensive laboratory set-up, we have shown that connecting an extension cable to the seepmeter has a negligible effect on its measuring capability. Similarly, the observed influence of very low temperature (???3 ??C) on seepmeter measurements can be accounted for by conducting calibrations at such temperatures prior to field deployments. Compared to manual volumetric measurements, calibration experiments showed that at higher water flow rates (>28 cm day-1 or cm3 cm-2 day-1) an analog flowmeter overestimated flow rates by ???7%. This was apparently due to flow resistance, turbulence and formation of air bubbles in the seepmeter water flow tubes. Salinity had no significant effect on the performance of the seepmeter. Calibration results from fresh water and sea water showed close agreement at a 95% confidence level significance between the data sets from the two media (R2 = 0.98). Comparatively, the seepmeter SGD measurements provided data that are comparable to manually-operated seepage meters, the radon geochemical tracer approach, and an electromagnetic (EM) seepage meter. ?? 2009 Elsevier Ltd.

  12. Exploration and validation of alternate sensing methods for wearable continuous pulse transit time measurement using optical and bioimpedance modalities.

    Science.gov (United States)

    Ibrahim, Bassem; Nathan, Viswam; Jafari, Roozbeh

    2017-07-01

    In this work we explore the viability of a multimodal sensing device that can be integrated in a wearable form factor for daily, non-invasive ambulatory blood pressure (BP) monitoring. A common approach in previous research has been to rely on measuring the pulse transit time (PTT), which has been shown to be correlated with the BP. In this work, we look into the feasibility of measuring PTT using sensors separated by a small distance on one arm so that any eventual realization of the system is convenient to wear and use over long periods of time. Moreover, we investigate the combined use of two different modalities for cardiovascular measurement: the optical photoplethysmogram (PPG) as well as the bio-potential based impedance (Bio-Z) measurement. These two modalities have been previously only studied on their own or in conjunction with the electrocardiogram (ECG) for the purpose of estimating PTT. We measure the PTT from the wrist to the finger using Bio-Z and PPG sensors, and compare it to the conventional PTT measured from the ECG to PPG at the finger, in order to prove that it can be an effective replacement for existing PTT measurement strategies. Moreover, successful measurement of PTT with two different modalities of sensors at close proximity will allow designs with multiple heterogeneous sensors on a more versatile wearable sensing platform that is optimized for power and is more robust to environmental or skin contact changes. This will enable the next generation of smart watches that capture PTT and BP. Experiments were conducted in vivo with simultaneous ECG, Bio-Z and PPG sensors, and results indicate that the PTT calculated from the Bio-Z and PPG sensors placed at a close distance correlates well with the more established PTT measurement using the ECG in conjunction with PPG, with correlation coefficient as high as 0.92.

  13. TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

    International Nuclear Information System (INIS)

    Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C.; Fabrycky, Daniel C.; Steffen, Jason H.; Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David; Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A.; Welsh, William F.; Allen, Christopher; Batalha, Natalie M.; Buchhave, Lars A.

    2012-01-01

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  14. 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.

  15. New Insights on Planet Formation in WASP-47 from a Simultaneous Analysis of Radial Velocities and Transit Timing Variations

    Science.gov (United States)

    Weiss, Lauren M.; Deck, Katherine M.; Sinukoff, Evan; Petigura, Erik A.; Agol, Eric; Lee, Eve J.; Becker, Juliette C.; Howard, Andrew W.; Isaacson, Howard; Crossfield, Ian J. M.; Fulton, Benjamin J.; Hirsch, Lea; Benneke, Björn

    2017-06-01

    Measuring precise planet masses, densities, and orbital dynamics in individual planetary systems is an important pathway toward understanding planet formation. The WASP-47 system has an unusual architecture that motivates a complex formation theory. The system includes a hot Jupiter (“b”) neighbored by interior (“e”) and exterior (“d”) sub-Neptunes, and a long-period eccentric giant planet (“c”). We simultaneously modeled transit times from the Kepler K2 mission and 118 radial velocities to determine the precise masses, densities, and Keplerian orbital elements of the WASP-47 planets. Combining RVs and TTVs provides a better estimate of the mass of planet d (13.6+/- 2.0 {M}\\oplus ) than that obtained with only RVs (12.75+/- 2.70 {M}\\oplus ) or TTVs (16.1+/- 3.8 {M}\\oplus ). Planets e and d have high densities for their size, consistent with a history of photoevaporation and/or formation in a volatile-poor environment. Through our RV and TTV analysis, we find that the planetary orbits have eccentricities similar to the solar system planets. The WASP-47 system has three similarities to our own solar system: (1) the planetary orbits are nearly circular and coplanar, (2) the planets are not trapped in mean motion resonances, and (3) the planets have diverse compositions. None of the current single-process exoplanet formation theories adequately reproduce these three characteristics of the WASP-47 system (or our solar system). We propose that WASP-47, like the solar system, formed in two stages: first, the giant planets formed in a gas-rich disk and migrated to their present locations, and second, the high-density sub-Neptunes formed in situ in a gas-poor environment.

  16. 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.

  17. Weighing Scale-Based Pulse Transit Time is a Superior Marker of Blood Pressure than Conventional Pulse Arrival Time

    Science.gov (United States)

    Martin, Stephanie L.-O.; Carek, Andrew M.; Kim, Chang-Sei; Ashouri, Hazar; Inan, Omer T.; Hahn, Jin-Oh; Mukkamala, Ramakrishna

    2016-12-01

    Pulse transit time (PTT) is being widely pursued for cuff-less blood pressure (BP) monitoring. Most efforts have employed the time delay between ECG and finger photoplethysmography (PPG) waveforms as a convenient surrogate of PTT. However, these conventional pulse arrival time (PAT) measurements include the pre-ejection period (PEP) and the time delay through small, muscular arteries and may thus be an unreliable marker of BP. We assessed a bathroom weighing scale-like system for convenient measurement of ballistocardiography and foot PPG waveforms - and thus PTT through larger, more elastic arteries - in terms of its ability to improve tracking of BP in individual subjects. We measured “scale PTT”, conventional PAT, and cuff BP in humans during interventions that increased BP but changed PEP and smooth muscle contraction differently. Scale PTT tracked the diastolic BP changes well, with correlation coefficient of -0.80 ± 0.02 (mean ± SE) and root-mean-squared-error of 7.6 ± 0.5 mmHg after a best-case calibration. Conventional PAT was significantly inferior in tracking these changes, with correlation coefficient of -0.60 ± 0.04 and root-mean-squared-error of 14.6 ± 1.5 mmHg (p < 0.05). Scale PTT also tracked the systolic BP changes better than conventional PAT but not to an acceptable level. With further development, scale PTT may permit reliable, convenient measurement of BP.

  18. Dry Electrodes for ECG and Pulse Transit Time for Blood Pressure: A Wearable Sensor and Smartphone Communication Approach

    Science.gov (United States)

    Shyamkumar, Prashanth

    -invasive, cuff-less Blood pressure estimation based on Pulse Transit Time with multiple synchronized sensor nodes, is implemented with e-nanoflex and the results are discussed.

  19. Analysis of Simultaneous Gas-Liquid Flow Through an Orifice and Its Application to Flow Metering Etude de l'écoulement simultané d'un mélange gaz-liquide à travers un orifice et son application à la mesure du débit

    Directory of Open Access Journals (Sweden)

    Pascal H.

    2006-11-01

    Full Text Available The purpose of this article is to show a more accurate orifice equation for a two-phase flow, such a compressible mixture of gas and liquid. The orifice equation given here con be used for the measurement of a gas-liquid mixture of fine emulsions by the orificemeter method. From the thermodynamic point of view, an equation of state has been formulated which provides the relationship between the specific mass of the mixture and pressure, under conditions of adiabatic expansion. The results obtained enable the mass flow rates of gas and liquid ta be determined without separation of the phases, provided thot the gas liquid mass ratio is known. The critical pressure ratio corresponding ta sonic velocity is also determined. Cet article présente une relation plus précise pour l'écoulement d'un système à deux phases, tel qu'un mélange compressible gaz-liquide, à travers un diaphragme. Cette relation peut être utilisée pour des mesures de mélanges gaz-liquide très finement divisés, c'est-à-dire des émulsions ou brouillards, par la méthode du diaphragme en paroi mince. Du point de vue thermodynamique, on a formulé une équation d'état donnant la relation entre la masse spécifique du mélange et la pression dans des conditions d'expansion adiabatique. Les résultats obtenus per-mettent de déterminer le débit massique du gaz et du liquide, sans séparation des deux phases, à condition que le rapport de masse gaz-liquide soit connu. On détermine également le rapport de pression critique correspondantà la vitesse du son.

  20. Population In Vitro-In Vivo Correlation Model Linking Gastrointestinal Transit Time, pH, and Pharmacokinetics: Itraconazole as a Model Drug.

    Science.gov (United States)

    Abuhelwa, Ahmad Y; Mudge, Stuart; Hayes, David; Upton, Richard N; Foster, David J R

    2016-07-01

    To establish an in vitro-in vivo correlation (IVIVC) model for Sporanox and SUBA-itraconazole formulations and to understand the impact of gastrointestinal (GI) pH and transit times on itraconazole dissolution and absorption. IVIVC was developed based on fed/fasted pharmacokinetic data from randomized cross-over trials, in vitro dissolution studies, and prior information about typical and between subject variability of GI pH and transit times. Data were analysed using the population modelling approach as implemented in NONMEM. Dissolution kinetics were described using first order models. The in vivo pharmacokinetics of itraconazole was described with a 2-compartment model with 4-transit absorption compartments. Pharmacokinetic profiles for fasted itraconazole periods were described based on the in vitro dissolution model, in vivo disposition model, and the prior information on GI pH and transit times. The IVIVC model indicated that drug dissolution in the fed state required an additional pH-independent dissolution pathway. The IVIVC models were presented in a 'Shiny' application. An IVIVC model was established and internally evaluated for the two itraconazole formulations. The IVIVC model provides more insight into the observed variability of itraconazole pharmacokinetics and indicated that GI pH and transit times influence in vivo dissolution and exposure.

  1. Quantifying the sources and the transit times of sediment using fallout radionuclides (7Be, 137Cs, 210Pbxs) in contrasted cultivated catchments across the world

    Science.gov (United States)

    Evrard, O.; Le Gall, M.; Laceby, J. P.; Foucher, A.; Lefèvre, I.; Salvador-Blanes, S.; Morera, S.; Ribolzi, O.

    2017-12-01

    Soil erosion and fine sediment supply to rivers are exacerbated in intensively cultivated catchments. Information on the sediment sources and transit times in rivers is required to improve our understanding of these processes and to guide the implementation of effective conservation measures. Accordingly, natural (7Be, 210Pb) and artificial (137Cs) fallout radionuclide concentrations were measured in overland flow and suspended sediment collected during the erosive season in contrasted cultivated catchments. In Laos, samples were collected in a steep catchment (Houay Pano, 12 km²) covered with cropland and teak plantations during the first flood of the monsoon in 2014. Cropland surface sources dominated the supply of sediment at the upstream sampling location (55%), whereas subsurface sources (channel, landslides) contributed the majority of material at the outlet (60%). Furthermore, the material exported from the catchment mainly consisted of re-suspended sediment. In Central France, the study was conducted in a flat and drained cultivated catchment (Louroux, 25 km²) during a sequence of winter events in 2013-2014 and 2016. Only surface material enriched in 137Cs was found to transit through the river during floods. The results demonstrated the initial re-suspension of material accumulated in the river channel during the first winter flood before the direct supply of sediment recently eroded from the hillslopes during the next events. In Peru, sediment was collected during a series of summer flood events (2017) in a river draining páramos (Ronquillo, 42 km²) that were recently put in cultivation. Preliminary results show that subsurface re-suspended material dominates the exports from this catchment. These results confirmed the utility of coupling continuous river monitoring and fallout radionuclide measurements on sediment collected in both tropical and temperate rivers to better understand sediment dynamics in these endangered habitats. The main challenges

  2. Inferring Transit Time Distributions from Atmospheric Tracer Data: Assessment of Predictive Capacities of Lumped Parameter Models on a 3D Crystalline Aquifer Model

    Science.gov (United States)

    Marçais, J.; De Dreuzy, J. R.; Ginn, T. R.; Gueutin, P.; Leray, S.

    2014-12-01

    Transit time distributions (TTDs) play a key role in the transport processes, the interpretation of atmospheric tracer data and the predictions made on groundwater resources. However TTDs are not accessible from field measurements. Only hints on these TTDs can be obtained from anthropogenic tracer concentrations, also commonly called "groundwater ages". We evaluate the predictive capabilities of the information contained in anthropogenic tracer concentrations on groundwater renewal times through the use of Lumped Parameter Models (LPMs) instead of fully developed aquifer models. Towards this end, we develop an assessment methodology in three steps. First, a synthetic crystalline aquifer model representing the site of Plœmeur (Brittany, France) is used to give, at any point, references for observables quantities (anthropogenic tracer concentrations of CFC-11, 85Kr and SF6), for non-observables quantities (the TTDs), and for the prediction objective (groundwater renewal times). Second, several LPMs are considered with one, two or three parameters, and are parameterized by fitting the reference anthropogenic concentrations. Third, the reference renewal times obtained from the synthetic model are compared to the renewal times obtained independently from the LPMs. Statistical analyses over the aquifer show that a good fit of the anthropogenic tracer concentrations is a necessary but not sufficient condition for acceptable predictions. The use of only one anthropogenic tracer gives poor predictions differing by 7 to 12 years to the references. The use of two sufficiently different anthropogenic tracers not only reduce the errors but surprisingly yield to very accurate predictions with errors smaller than 3 years. The additional use of a third anthropogenic tracer does not improve the predictive capabilities. Careful a posteriori analyses reveal that reference TTDs have widely varying shapes from well peaked in recharge zones where flows are diverging to broadly

  3. Measurement of flow in viscous fluids

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Chris [NEL Technology for Life (Mexico)

    2011-07-01

    Taking accurate flow measurements of viscous fluids can prove to be a difficult task. The process faces a number of challenges which include pressure losses, varying velocity profiles, higher viscous friction, and the presence of solids or gas. In this presentation NEL, holder of UK's National Standards for flow measurement, shares a test that was conducted to identify the influencing factors of flow measurements for viscous fluids. The test, which was conducted at NEL's National Standards oil flow facility, utilizes three test meters. The first test meter used was a multi-path ultrasonic meter, the other two were twin-tube coriolis meters of different sizes. Readings were taken from each meter for kerosene and primol at varying degrees of viscosity. Adjustments in flowrate and temperature were also made and recorded throughout the test. From the tests, NEL was able to generate data regarding the factors impacting mass flowrate, density, and pressure.

  4. Quantitative cholescintigraphy in the assessment of choledochoduodenal bile flow

    Energy Technology Data Exchange (ETDEWEB)

    Cicala, M.; Scopinaro, F.; Corazziari, E.; Vignoni, A.; Viscardi, A.; Habib, F.I.; Torsoli, A. (Universita La Sapienza, Rome (Italy))

    1991-04-01

    Quantitative cholescintigraphy has been proposed as a noninvasive method to assess function of the sphincter of Oddi in cholecystectomized subjects. The present study evaluated several quantitative cholescintigraphic variables to assess their time-related variability as well as their capability to detect delay of choledochoduodenal bile flow. Cholescintigraphy with 2,6-diethylphenylcarbahoylmethyl diacetic acid 99mTc was performed in 24 cholecystectomized patients with recurrent biliary-like pain, laboratory evidence of bile stasis, normal hepatocellular function tests, and no evidence of choledocholithiasis. The study was also performed in 26 asymptomatic cholecystectomized subjects and repeated at 2-week intervals during identical experimental conditions in 10 of them. Of the following quantitative cholescintigraphic variables investigated, (a) hepatic T peak, (b) 50% hepatic retention (T peak, 1/2), (c) percent hepatic retention at 30 minutes, (d) percent hepatic retention at 40 minutes, (e) vein-hepatic hilum transit time, (f) vein-duodenum transit time, and (g) hepatic hilum-duodenum transit time, only the hepatic hilum-duodenum transit time showed a statistically significant correlation between the duplicate studies. Only vein-duodenum transit time and hepatic hilum-duodenum transit time discriminated the symptomatic from the asymptomatic patients; of the two variables, however, hepatic hilum-duodenum transit time showed less intrasubject variability and no overlap between the two groups of patients. Hepatic hilum-duodenum transit time showed a positive linear correlation with the maximum diameter of the choledochus. It is concluded that in cholecystectomized patients, the hepatic hilum-duodenum transit time appears to detect a delay of bile flow into the intestine better than any other cholescintigraphic variable.

  5. Development and evaluation of an automated system for testing current meters

    Directory of Open Access Journals (Sweden)

    Ezequiel Saretta

    2016-02-01

    Full Text Available ABSTRACT Current meters are equipment widely used for estimating flow velocity in rivers and streams. Periodic calibrations of current meters are important to ensure the quality of measurements, but the required testing facilities are complex and only available in a few institutions. However, advances in electronics and automation may contribute to developing simple and reliable calibration systems. Thus, this study aimed to develop an automated system for testing current meters, which consisted of a trapezoidal channel, a step motor, a tow car and a management system, composed of a supervisory application and microprocessed modules to control the motor and the data acquisition. Evaluations of the displacement velocity showed that it matched the reference value up to 1.85 m s-1 for a vertical-axis current meter and 2.3 m s-1 for a horizontal-axis one. The developed system showed reliability during tests, for both current meter movement and data acquisition. The management of the system based on the developed modules and the supervisory application improved its user interface, turning all the procedure into a simple task.

  6. Evaluation of mean transit time of aerosols from the area of origin to the Arctic with210Pb/210Po daily monitoring data.

    Science.gov (United States)

    Zhang, Weihua; Sadi, Baki; Rinaldo, Christopher; Chen, Jing; Spencer, Norman; Ungar, Kurt

    2017-10-16

    In this study, the activity concentrations of 210 Pb and 210 Po on the 22 daily air filter samples, collected at CTBT Yellowknife station from September 2015 to April 2016, were analysed. To estimate the time scale of atmospheric long-range transport aerosol bearing 210 Pb in the Arctic during winter, the mean transit time of aerosol bearing 210 Pb from its origin was determined based on the activity ratios of 210 Po/ 210 Pb and the parent-progeny decay/ingrowth equation. The activity ratios of 210 Po/ 210 Pb varied between 0.06 and 0.21 with a median value of 0.11. The aerosol mean transit time based the activity ratio of 210 Po/ 210 Pb suggests longer mean transit time of 210 Pb aerosols in winter (12 d) than in autumn (3.7 d) and spring (2.9 d). Four years 210 Pb and 212 Pb monitoring results and meteorological conditions at the Yellowknife station indicate that the 212 Pb activity is mostly of local origin, and that 210 Pb aerosol in wintertime are mainly from outside of the Arctic regions in common with other pollutants and sources contributing to the Arctic. The activity concentration ratios of 210 Pb and 212 Pb have a relatively constant value in summer with a significant peak observed in winter, centered in the month of February. Comparison of the 210 Pb/ 212 Pb activity ratios and the estimated mean 210 Pb transit time, the mean aerosol transit times were real reflection of the atmosphere transport characteristics, which can be used as a radio-chronometer for the transport of air masses to the Arctic region. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  7. Integrating an embedded system in a microwave moisture meter

    Science.gov (United States)

    The conversion of a PC- or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter measures the attenuation and phase shift of low power microwaves traversing the sample, from which the dielectric properties are calculated. T...

  8. Integrating an Embedded System within a Microwave Moisture Meter

    Science.gov (United States)

    In this paper, the conversion of a PC or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter uses low-power microwaves to measure the attenuation and phase shift of the sample, from which the dielectric properties are cal...

  9. A prepaid meter using mobile communication | Jain | International ...

    African Journals Online (AJOL)

    sophisticated and accurate digital and electronic meters. A high percentage of electricity revenue is lost to power theft, incorrect meter reading and billing, and reluctance of consumers towards paying electricity bills on time. Considerable amount of revenue losses can be reduced by using Prepaid Energy Meters. A prepaid ...

  10. 18 CFR 367.9020 - Account 902, Meter reading expenses.

    Science.gov (United States)

    2010-04-01

    ... clocks, checking seals, and other similar items, when performed by meter readers and the work represents... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Account 902, Meter... GAS ACT Operation and Maintenance Expense Chart of Accounts § 367.9020 Account 902, Meter reading...

  11. 24 CFR 965.401 - Individually metered utilities.

    Science.gov (United States)

    2010-04-01

    ... URBAN DEVELOPMENT PHA-OWNED OR LEASED PROJECTS-GENERAL PROVISIONS Individual Metering of Utilities for Existing PHA-Owned Projects § 965.401 Individually metered utilities. (a) All utility service shall be... supplier or through the use of checkmeters, unless: (1) Individual metering is impractical, such as in the...

  12. 7 CFR 801.6 - Tolerances for moisture meters.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Tolerances for moisture meters. 801.6 Section 801.6... FOR GRAIN INSPECTION EQUIPMENT § 801.6 Tolerances for moisture meters. (a) The maintenance tolerances for Motomco 919 moisture meters used in performing official inspection services shall be: (1...

  13. The disc pasture meter: Possible applications in grazing management.

    African Journals Online (AJOL)

    The disc meter is a simple inexpensive instrument which may be used to make rapid yield estimates of standing forage. Linear regression relationships between meter reading and pasture dry matter yield are usually fairly good, but these may be affected by a number of different factors. The meter should therefore be ...

  14. Static energy meter errors caused by conducted electromagnetic interference

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes; Keyer, Cornelis H.A.; Melentjev, Anton

    2017-01-01

    Static, or electronic, energy meters are replacing the conventional electromechanical meters. Consumers are some-times complaining about higher energy readings and billing after the change to a static meter, but there is not a clear common or root cause at present. Electromagnetic interference has

  15. 49 CFR 192.357 - Customer meters and regulators: Installation.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Customer meters and regulators: Installation. 192... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.357 Customer meters and regulators: Installation. (a...

  16. 49 CFR 192.359 - Customer meter installations: Operating pressure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Customer meter installations: Operating pressure... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.359 Customer meter installations: Operating pressure...

  17. NUCLEAR MIXING METERS FOR CLASSICAL NOVAE

    International Nuclear Information System (INIS)

    Kelly, Keegan J.; Iliadis, Christian; Downen, Lori; Champagne, Art; José, Jordi

    2013-01-01

    Classical novae are caused by mass transfer episodes from a main-sequence star onto a white dwarf via Roche lobe overflow. This material possesses angular momentum and forms an accretion disk around the white dwarf. Ultimately, a fraction of this material spirals in and piles up on the white dwarf surface under electron-degenerate conditions. The subsequently occurring thermonuclear runaway reaches hundreds of megakelvin and explosively ejects matter into the interstellar medium. The exact peak temperature strongly depends on the underlying white dwarf mass, the accreted mass and metallicity, and the initial white dwarf luminosity. Observations of elemental abundance enrichments in these classical nova events imply that the ejected matter consists not only of processed solar material from the main-sequence partner but also of material from the outer layers of the underlying white dwarf. This indicates that white dwarf and accreted matter mix prior to the thermonuclear runaway. The processes by which this mixing occurs require further investigation to be understood. In this work, we analyze elemental abundances ejected from hydrodynamic nova models in search of elemental abundance ratios that are useful indicators of the total amount of mixing. We identify the abundance ratios ΣCNO/H, Ne/H, Mg/H, Al/H, and Si/H as useful mixing meters in ONe novae. The impact of thermonuclear reaction rate uncertainties on the mixing meters is investigated using Monte Carlo post-processing network calculations with temperature-density evolutions of all mass zones computed by the hydrodynamic models. We find that the current uncertainties in the 30 P(p, γ) 31 S rate influence the Si/H abundance ratio, but overall the mixing meters found here are robust against nuclear physics uncertainties. A comparison of our results with observations of ONe novae provides strong constraints for classical nova models

  18. Digital radioisotope moisture-density meter

    International Nuclear Information System (INIS)

    Bychvarov, N.; Vankov, I.; Dimitrov, L.

    1982-01-01

    The primary information from the detectors of a combined radioisotope moisture-density meter is obtained as pulses, their counting rate being functionally dependent on the humidity per unit volume and the wet density. However, most practical cases demand information on the moisture per unit weight and the mass density of the dry skeleton. The paper describes how the proposed electronic circuit processes the input primary information to obtain the moisture in weight % and the mass density of the dry skeleton in g/cm 3 . (authors)

  19. Ramp - Metering Algorithms Evaluated within Simplified Conditions

    Science.gov (United States)

    Janota, Aleš; Holečko, Peter; Gregor, Michal; Hruboš, Marián

    2017-12-01

    Freeway networks reach their limits, since it is usually impossible to increase traffic volumes by indefinitely extending transport infrastructure through adding new traffic lanes. One of the possible solutions is to use advanced intelligent transport systems, particularly ramp metering systems. The paper shows how two particular algorithms of local and traffic-responsive control (Zone, ALINEA) can be adapted to simplified conditions corresponding to Slovak freeways. Both control strategies are modelled and simulated using PTV Vissim software, including the module VisVAP. Presented results demonstrate the properties of both control strategies, which are compared mutually as well as with the initial situation in which no control strategy is applied

  20. PRESCILA: a new, lightweight neutron rem meter.

    Science.gov (United States)

    Olsher, Richard H; Seagraves, David T; Eisele, Shawna L; Bjork, Christopher W; Martinez, William A; Romero, Leonard L; Mallett, Michael W; Duran, Michael A; Hurlbut, Charles R

    2004-06-01

    Conventional neutron rem meters currently in use are based on 1960's technology that relies on a large neutron moderator assembly surrounding a thermal detector to achieve a rem-like response function over a limited energy range. Such rem meters present an ergonomic challenge, being heavy and bulky, and have caused injuries during radiation protection surveys. Another defect of traditional rem meters is a poor high-energy response above 10 MeV, which makes them unsuitable for applications at high-energy accelerator facilities. Proton Recoil Scintillator-Los Alamos (PRESCILA) was developed as a low-weight (2 kg) alternative capable of extended energy response, high sensitivity, and moderate gamma rejection. An array of ZnS(Ag) based scintillators is located inside and around a Lucite light guide, which couples the scintillation light to a sideview bialkali photomultiplier tube. The use of both fast and thermal scintillators allows the energy response function to be optimized for a wide range of operational spectra. The light guide and the borated polyethylene frame provide moderation for the thermal scintillator element. The scintillators represent greatly improved versions of the Hornyak and Stedman designs from the 1950's, and were developed in collaboration with Eljen Technology. The inherent pulse height advantage of proton recoils over electron tracks in the phosphor grains eliminates the need for pulse shape discrimination and makes it possible to use the PRESCILA probe with standard pulse height discrimination provided by off-the-shelf health physics counters. PRESCILA prototype probes have been extensively tested at both Los Alamos and the German Bureau of Standards, Physikalisch-Technische Bundesanstalt. Test results are presented for energy response, directional dependence, linearity, sensitivity, and gamma rejection. Initial field tests have been conducted at Los Alamos and these results are also given. It is concluded that PRESCILA offers a viable

  1. Fibre optic power meter calibration uncertainties

    CSIR Research Space (South Africa)

    Nel, M

    2010-06-01

    Full Text Available The method to empirically quantify the effect that flexing (movement) of the fibre has on the output power was determined by connecting an optical fibre to a power meter head and performing controlled movements of the head (displacements and rotations..., and with their optical axes roughly parallel to one another to reduce the effect of fibre flexing when interchanging from one detector head to another. Excessive flexing and moving of the fibre can cause differences in the radiant power emerging from the fibre...

  2. EPA Region 1 - Valley Depth in Meters

    Science.gov (United States)

    Raster of the Depth in meters of EPA-delimited Valleys in Region 1.Valleys (areas that are lower than their neighbors) were extracted from a Digital Elevation Model (USGS, 30m) by finding the local average elevation, subtracting the actual elevation from the average, and selecting areas where the actual elevation was below the average. The landscape was sampled at seven scales (circles of 1, 2, 4, 7, 11, 16, and 22 km radius) to take into account the diversity of valley shapes and sizes. Areas selected in at least four scales were designated as valleys.

  3. Data report for current meters on mooring CMME-2, 1981-82; Atlantic study ar EN-3

    International Nuclear Information System (INIS)

    The mooring designated CMME-2 was installed by R/V Endeavor on the northern Hatteras Abyssal Plain in an acoustically measured water depth of 5410 corrected meters. It was recovered after 333 days of operation. All five meters were recovered. The speed sensor on the top meter failed after 3.5 months; therefore its speed and direction files are short. The bottom meter failed during installation and produced no data. CMME-2 is the second mooring in a planned series of moorings near the center of the study area E-N3. The series of moorings is designed to determine the long-term mean flow in the study area. The data collected will be used as input in a numerical circulation model of the region. In addition the long time series of data will allow the study of energetic fluctuations at low frequencies. The mean speeds recorded are lower than those from the earlier record. In contrast to the previous data there appears to be no subsurface speed maximum. There is a fairly consistent northerly flow on which is superimposed a more variable east-west flow. A seasonal trend may be present: flow to the east in spring, flow to the south in the fall, and flow to the north in winter. 4 references, 56 figures, 4 tables

  4. Smart meter users give a thumbs up

    International Nuclear Information System (INIS)

    Horne, D.

    2007-01-01

    The Ontario Energy Board conducted a pilot study with the support of Hydro Ottawa to better understand how consumers change their electricity consumption behaviour with smart meters and time-of-use (TOU) prices. The project enabled consumers to learn the most cost-effective times to use energy. Results from the Ontario Smart Price Pilot reveal that consumers like to have control over how much and when they use their electricity. Although the savings were only small for some clients involved in the study, they appreciated having their metering bills in greater detail. At the end of the pilot project, participants reduced electricity consumption by 6 per cent. Nearly 90 per cent of the participants paid lower energy bills and nearly 80 per cent indicated they would recommend TOU pricing to their friends because it motivated them to shift some of their electricity use away from peak hours. The average reduction in electricity demand among the two-thirds of participants on critical pricing plans was more than 20 per cent during high demand or critical peak hours in summer. Demand reduction on winter critical peak days was much lower for all participants. 1 fig

  5. The reactor neutron flux and period measure meter

    International Nuclear Information System (INIS)

    Wei Ying

    1997-11-01

    The main performance indexes of developed reactor neutron flux and period measure meter (as an intermediate range measuring instrument of nuclear instrumentation system in nuclear power plant) are introduced. The meter's function, working principle, hardware constitution, application software, and the characteristics of the meter are described. The meter adopts the advanced digital technology, it can do calculating and processing by a microprocessor to get the values of power and period. It also can give the output singles as required. The characters of the meter are high accuracy, good ability to resist disturbance, small temperature coefficient and convenient for operation, etc

  6. A Novel Smart Meter Controlling System with Dynamic IP Addresses

    DEFF Research Database (Denmark)

    Manembu, Pinrolinvic; Welang, Brammy; Kalua Lapu, Aditya

    2017-01-01

    Smart meters are the electronic devices for measuring energy consumption in real time. Usually, static public IP addresses are allocated to realize the point-to-point (P2P) communication and remote controlling for smart metering systems. This, however, restricts the wide deployment of smart meters......, due to the deficiency of public IP resources. This paper proposes a novel subscription-based communication architecture for the support of dynamic IP addresses and group controlling of smart meters. The paper evaluates the proposed architecture by comparing the traditional P2P architecture......, and validate its effectiveness to interact with smart meters....

  7. Automatic ranging circuit for a digital panel meter

    International Nuclear Information System (INIS)

    Mueller, T.R.; Ross, H.H.

    1976-01-01

    This invention relates to a range changing circuit that operates in conjunction with a digital panel meter of fixed sensitivity. The circuit decodes the output of the panel meter and uses that information to change the gain of an input amplifier to the panel meter in order to ensure that the maximum number of significant figures is always displayed in the meter. The circuit monitors five conditions in the meter and responds to any of four combinations of these conditions by means of logic elements to carry out the function of the circuit. The system was designed for readout of a fluorescence analyzer for uranium analysis

  8. Long Island Smart Metering Pilot Project

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-03-30

    The Long Island Power Authority (LIPA) Smart Meter Pilots provided invaluable information and experience for future deployments of Advanced Metering Infrastructure (AMI), including the deployment planned as part of LIPA's Smart Grid Demonstration Project (DE-OE0000220). LIPA will incorporate lessons learned from this pilot in future deployments, including lessons relating to equipment performance specifications and testing, as well as equipment deployment and tracking issues. LIPA ultimately deployed three AMI technologies instead of the two that were originally contemplated. This enabled LIPA to evaluate multiple systems in field conditions with a relatively small number of meter installations. LIPA experienced a number of equipment and software issues that it did not anticipate, including issues relating to equipment integration, ability to upgrade firmware and software over the air (as opposed to physically interacting with every meter), and logistical challenges associated with tracking inventory and upgrade status of deployed meters. In addition to evaluating the technology, LIPA also piloted new Time-of-Use (TOU) rates to assess customer acceptance of time-differentiated pricing and to evaluate whether customers would respond by adjusting their activities from peak to non-peak periods. LIPA developed a marketing program to educate customers who received AMI in the pilot areas and to seek voluntary participation in TOU pricing. LIPA also guaranteed participating customers that, for their initial year on the rates, their electricity costs under the TOU rate would not exceed the amount they would have paid under the flat rates they would otherwise enjoy. 62 residential customers chose to participate in the TOU rates, and every one of them saved money during the first year. 61 of them also elected to stay on the TOU rate without the cost guarantee at the end of that year. The customer who chose not to continue on the rate was also the one who achieved the

  9. A hybrid ICT-solution for smart meter data analytics

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Nielsen, Per Sieverts

    2016-01-01

    Smart meters are increasingly used worldwide. Smart meters are the advanced meters capable of measuring energy consumption at a fine-grained time interval, e.g., every 15 min. Smart meter data are typically bundled with social economic data in analytics, such as meter geographic locations, weather...... conditions and user information, which makes the data sets very sizable and the analytics complex. Data mining and emerging cloud computing technologies make collecting, processing, and analyzing the so-called big data possible. This paper proposes an innovative ICT-solution to streamline smart meter data...... analytics. The proposed solution offers an information integration pipeline for ingesting data from smart meters, a scalable platform for processing and mining big data sets, and a web portal for visualizing analytics results. The implemented system has a hybrid architecture of using Spark or Hive for big...

  10. A Smart Soft Sensor Predicting Feedwater Flow Rate

    International Nuclear Information System (INIS)

    Yang, Heon Young; Na, Man Gyun

    2009-01-01

    Since we evaluate thermal nuclear reactor power with secondary system calorimetric calculations based on feedwater flow rate measurements, we need to measure the feedwater flow rate accurately. The Venturi flow meters that are being used to measure the feedwater flow rate in most pressurized water reactors (PWRs) measure the flow rate by developing a differential pressure across a physical flow restriction. The differential pressure is then multiplied by a calibration factor that depends on various flow conditions in order to calculate the feedwater flow rate. The calibration factor is determined by the feedwater temperature and pressure. However, Venturi meters cause a buildup of corrosion products near the orifice of the meter. This fouling increases the measured pressure drop across the meter, thereby causing an overestimation of the feedwater flow rate

  11. Berthold contamination meter type LB1210B

    International Nuclear Information System (INIS)

    Burgess, P.H.; Iles, W.J.

    1981-04-01

    This instrument is a well designed, well constructed contamination monitor that has unusual versatility. Where large surface areas require to be monitored it is particularly useful because of the large area of the detector. It is suitable for monitoring β surface contamination of energy equal to and above that of 14 C, and for X- and low-energy γ-emitting nuclides. It has an adequate battery life, good temperature stability, comprehensive but simple controls, and a clear and accurate meter. A useful check source is provided. The only criticisms of the limitations of the alarm warning, the rather quiet click for each event detected, the rough surface finish, and the effects of high humidity. (author)

  12. Handheld Multi-Gas Meters Assessment Report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Gustavious [Brigham Young Univ., Provo, UT (United States); Wald-Hopkins, Mark David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Obrey, Stephen J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Akhadov, Valida Dushdurova [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-27

    Handheld multi-gas meters (MGMs) are equipped with sensors to monitor oxygen (O2) levels and additional sensors to detect the presence of combustible or toxic gases in the environment. This report is limited to operational response-type MGMs that include at least four different sensors. These sensors can vary by type and by the monitored chemical. In real time, the sensors report the concentration of monitored gases in the atmosphere near the MGM. In April 2016 the System Assessment and Validation for Emergency Responders (SAVER) Program conducted an operationally-oriented assessment of MGMs. Five MGMs were assessed by emergency responders. The criteria and scenarios used in this assessment were derived from the results of a focus group of emergency responders with experience in using MGMs. The assessment addressed 16 evaluation criteria in four SAVER categories: Usability, Capability, Maintainability, and Deployability.

  13. Radiation survey meters used for environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Bjerke, H. (ed.) (Norwegian Radiation Protection Authority, NRPA (Norway)); Sigurdsson, T. (Icelandic Radiation Safety Authority, Geislavarnir Rikisins, GR (IS)); Meier Pedersen, K. (National Board of Health, Statens Institut for Straalebeskyttelse (SIS) (Denmark)); Grindborg, J.-E.; Persson, L. (Swedish Radiation Safety Authority, Straalsaekerhetsmyndigheten (SSM) (Sweden)); Siiskonen, T.; Hakanen, A.; Kosunen, A. (Radiation and Nuclear Safety Authority, Saeteilyturvakeskus (STUK) (Finland))

    2012-01-15

    The Nordic dosimetry group set up the GammaRate project to investigate how its expertise could be used to assure appropriate usage of survey meters in environmental monitoring. Considerable expertise in calibrating radiation instruments exists in the Nordic radiation protection authorities. The Swedish, Finnish, Danish and Norwegian authorities operate Secondary Standard Dosimetry Laboratories (SSDLs) that provide users with calibration traceable to internationally recognised primary standards. These authorities together with the Icelandic authorities have formally cooperated since 2002 in the field of radiation dosimetry. Dosimetry is the base for assesment of risk from ionising radiation and calibration of instruments is an imported part in dosimetry. The Nordic dosimetry group has been focused on cancer therapy. This work extends the cooperation to the dosimetry of radiation protection and environmental monitoring. This report contains the formal, theoretical and practical background for survey meter measurements. Nordic standards dosimetry laboratories have the capability to provide traceable calibration of instruments in various types of radiation. To verify and explore this further in radiation protection applications a set of survey instruments were sent between the five Nordic countries and each of the authority asked to provide a calibration coefficient for all instruments. The measurement results were within the stated uncertainties, except for some results from NRPA for the ionchamber based instrument. The comparison was shown to be a valuable tool to harmonize the calibration of radiation protection instruments in the Nordic countries. Dosimetry plays an important role in the emergency situations, and it is clear that better traceability and harmonised common guidelines will improve the emergency preparedness and health. (Author)

  14. Radiation survey meters used for environmental monitoring

    International Nuclear Information System (INIS)

    Bjerke, H.; Sigurdsson, T.; Meier Pedersen, K.; Grindborg, J.-E.; Persson, L.; Siiskonen, T.; Hakanen, A.; Kosunen, A.

    2012-01-01

    The Nordic dosimetry group set up the GammaRate project to investigate how its expertise could be used to assure appropriate usage of survey meters in environmental monitoring. Considerable expertise in calibrating radiation instruments exists in the Nordic radiation protection authorities. The Swedish, Finnish, Danish and Norwegian authorities operate Secondary Standard Dosimetry Laboratories (SSDLs) that provide users with calibration traceable to internationally recognised primary standards. These authorities together with the Icelandic authorities have formally cooperated since 2002 in the field of radiation dosimetry. Dosimetry is the base for assesment of risk from ionising radiation and calibration of instruments is an imported part in dosimetry. The Nordic dosimetry group has been focused on cancer therapy. This work extends the cooperation to the dosimetry of radiation protection and environmental monitoring. This report contains the formal, theoretical and practical background for survey meter measurements. Nordic standards dosimetry laboratories have the capability to provide traceable calibration of instruments in various types of radiation. To verify and explore this further in radiation protection applications a set of survey instruments were sent between the five Nordic countries and each of the authority asked to provide a calibration coefficient for all instruments. The measurement results were within the stated uncertainties, except for some results from NRPA for the ionchamber based instrument. The comparison was shown to be a valuable tool to harmonize the calibration of radiation protection instruments in the Nordic countries. Dosimetry plays an important role in the emergency situations, and it is clear that better traceability and harmonised common guidelines will improve the emergency preparedness and health. (Author)

  15. Evaluation of gastrointestinal tract transit times using barium-impregnated polyethylene spheres and barium sulfate suspension in a domestic pigeon (Columba livia) model.

    Science.gov (United States)

    Bloch, Rebecca A; Cronin, Kimberly; Hoover, John P; Pechman, Robert D; Payton, Mark E

    2010-03-01

    Barium impregnated polyethylene spheres (BIPS) are used in small animal medicine as an alternative to barium sulfate for radiographic studies of the gastrointestinal tract. To determine the usefulness of BIPS as an alternative to barium suspension in measuring gastrointestinal (GI) transit time for avian species, ventrodorsal radiographs were used to follow the passage of BIPS and 30% barium sulfate suspension through the GI tracts of domestic pigeons (Columba livia). Gastrointestinal transit times of thirty 1.5-mm BIPS administered in moistened gelatin capsules and 30% barium sulfate suspension gavaged into the crop were compared in 6 pigeons. Although the barium suspension passed out of the GI tract of all pigeons within 24 hours, the 1.5-mm BIPS remained in the ventriculus for 368.0 +/- 176.8 hours and did not clear the GI tract for 424.0 +/- 204.6 hours. Although the times for passage of BIPS and 30% barium sulfate suspension from the crop into the ventriculus were not significantly different (P = .14), the times for passage of BIPS from the ventriculus into the large intestine-cloaca and for clearance from the GI tract of the pigeons were significantly longer (P barium sulfate suspension. From the results of this study, we conclude that BIPS are not useful for radiographically evaluating GI transit times in pigeons and are unlikely to be useful in other avian species that have a muscular ventriculus. BIPS may or may not be useful for evaluating GI transit times in species that lack a muscular ventriculus.

  16. Hepatobiliary transit times of gadoxetate disodium (Primovist) for protocol optimization of comprehensive MR imaging of the biliary system-What is normal?

    International Nuclear Information System (INIS)

    Ringe, Kristina I.; Husarik, Daniela B.; Gupta, Rajan T.; Boll, Daniel T.; Merkle, Elmar M.

    2011-01-01

    Objective: The purpose of this study was to determine transit times for excretion of Gd-EOB-DTPA into different segments of the hepatobiliary system in patients with normal liver function. Methods: This retrospective study was IRB approved with a waiver of consent granted. 61 patients (39 female, 22 male, mean age 52.5 years) with normal liver and renal function who underwent contrast enhanced hepatic MRI after injection of 10 mLGd-EOB-DTPA at 1.5 T and 3 T were included. Two readers evaluated all delayed images (3-20 min post contrast) for the presence of contrast agent in the intrahepatic bile ducts (IBD), the common bile duct (CBD), the gallbladder and the duodenum. A two-tailed, unpaired Student's t-test with p < 0.05 deemed significant was used to determine whether transit times were affected by patient gender, age or body mass index. Results: 20 min after contrast initiation, Gd-EOB-DTPA could be detected in the IBD and the CBD in all patients (100%); gallbladder reflux was visible in 53 (86.9%), duodenal excretion in 40 patients (65.5%), respectively. Mean transit times for contrast appearance in the various segments were as follows: IBD 12 min 13 s; CBD 12 min 27 s; gallbladder 13 min 32 s. Transit times were not significantly affected by patient gender, age or BMI. Conclusion: Within 20 min post contrast initiation, Gd-EOB-DTPA can be expected in the IBD and the CBD in patients with normal liver function. However, functional information about the sphincter Oddi complex can be ascertained only in about two thirds of these patients within this timeframe.

  17. A Probabilistic Model of Meter Perception: Simulating Enculturation.

    Science.gov (United States)

    van der Weij, Bastiaan; Pearce, Marcus T; Honing, Henkjan

    2017-01-01

    Enculturation is known to shape the perception of meter in music but this is not explicitly accounted for by current cognitive models of meter perception. We hypothesize that the induction of meter is a result of predictive coding: interpreting onsets in a rhythm relative to a periodic meter facilitates prediction of future onsets. Such prediction, we hypothesize, is based on previous exposure to rhythms. As such, predictive coding provides a possible explanation for the way meter perception is shaped by the cultural environment. Based on this hypothesis, we present a probabilistic model of meter perception that uses statistical properties of the relation between rhythm and meter to infer meter from quantized rhythms. We show that our model can successfully predict annotated time signatures from quantized rhythmic patterns derived from folk melodies. Furthermore, we show that by inferring meter, our model improves prediction of the onsets of future events compared to a similar probabilistic model that does not infer meter. Finally, as a proof of concept, we demonstrate how our model can be used in a simulation of enculturation. From the results of this simulation, we derive a class of rhythms that are likely to be interpreted differently by enculturated listeners with different histories of exposure to rhythms.

  18. A Probabilistic Model of Meter Perception: Simulating Enculturation

    Directory of Open Access Journals (Sweden)

    Bastiaan van der Weij

    2017-05-01

    Full Text Available Enculturation is known to shape the perception of meter in music but this is not explicitly accounted for by current cognitive models of meter perception. We hypothesize that the induction of meter is a result of predictive coding: interpreting onsets in a rhythm relative to a periodic meter facilitates prediction of future onsets. Such prediction, we hypothesize, is based on previous exposure to rhythms. As such, predictive coding provides a possible explanation for the way meter perception is shaped by the cultural environment. Based on this hypothesis, we present a probabilistic model of meter perception that uses statistical properties of the relation between rhythm and meter to infer meter from quantized rhythms. We show that our model can successfully predict annotated time signatures from quantized rhythmic patterns derived from folk melodies. Furthermore, we show that by inferring meter, our model improves prediction of the onsets of future events compared to a similar probabilistic model that does not infer meter. Finally, as a proof of concept, we demonstrate how our model can be used in a simulation of enculturation. From the results of this simulation, we derive a class of rhythms that are likely to be interpreted differently by enculturated listeners with different histories of exposure to rhythms.

  19. Proceedings of the 2006 smart metering conference and expo

    International Nuclear Information System (INIS)

    2006-01-01

    Ontario's smart metering program was launched as part of a general demand response management strategy to improve energy conservation in the province. Smart metering will help consumers to control their electricity bills through conservation and demand response, and will allow consumers to better manage their energy consumption and use it more effectively during cheaper, off-peak times of day. Smart metering systems measure how much electricity a customer uses on an hourly basis, and data is transferred daily to local electricity distributors. Toronto Hydro will have close to 200,000 smart meters installed by the end of 2006. By 2010, Toronto will be North America's largest urban centre to have made the full transition to smart metering technology across its entire base. This conference provided an update of Toronto Hydro's smart metering project, as well as details of their demand response program. Presentations were given by a variety of experts in information technology as well as electric power industry leaders North American demand and response metering strategies were reviewed, as well as various initiatives in advanced metering infrastructure (AMI). Security risks associated with smart metering environments were reviewed. An evaluation of the current regulatory environment was presented along with a discussion of smart metering standards and compatibility issues. New metering technologies were presented as well as various associated demand side management tools. Smart metering pilot programs and initiatives were discussed, and best practices in smart metering were evaluated. Twenty-nine presentations were given at the conference, 13 of which have been indexed separately for inclusion in this database. refs., tabs., figs

  20. Radiofrequency energy exposure from the Trilliant smart meter.

    Science.gov (United States)

    Foster, Kenneth R; Tell, Richard A

    2013-08-01

    This paper reviews radiofrequency (RF) field levels produced by electric utility meters equipped with RF transceivers (so-called Smart Meters), focusing on meters from one manufacturer (Trilliant, Redwood City, CA, USA, and Granby, QC, Canada). The RF transmission levels are summarized based on publicly available data submitted to the U.S. Federal Communications Commission supplemented by limited independent measurements. As with other Smart Meters, this meter incorporates a low powered radiofrequency transceiver used for a neighborhood mesh network, in the present case using ZigBee-compliant physical and medium access layers, operating in the 2.45 GHz unlicensed band but with a proprietary network architecture. Simple calculations based on a free space propagation model indicate that peak RF field intensities are in the range of 10 mW m or less at a distance of more than 1-2 m from the meters. However, the duty cycle of transmission from the meters is very low (meter that were consistent with data reported by the vendor to the U.S. Federal Communications Commission. Limited measurements conducted in two houses with the meters were unable to clearly distinguish emissions from the meters from the considerable electromagnetic clutter in the same frequency range from other sources, including Wi-Fi routers and, when it was activated, a microwave oven. These preliminary measurements disclosed the difficulties that would be encountered in characterizing the RF exposures from these meters in homes in the face of background signals from other household devices in the same frequency range. An appendix provides an introduction to Smart Meter technology. The RF transmitters in wireless-equipped Smart Meters operate at similar power levels and in similar frequency ranges as many other digital communications devices in common use, and their exposure levels are very far below U.S. and international exposure limits.

  1. Mass determination of K2-19b and K2-19c from radial velocities and transit timing variations

    Science.gov (United States)

    Nespral, D.; Gandolfi, D.; Deeg, H. J.

    2017-03-01

    We present FIES@NOT and HARPS-N@TNG radial velocity follow-up observations of K2-19, a compact planetary system hosting three planets, of which the two larger ones, namely K2-19b and K2-19c, are close to the 3:2 mean motion resonance. The masses of these larger planets have previously been derived from transit timing only. An analysis considering only the radial velocity measurements is able to detect only K2-19b, the largest and more massive planet in the system, with a mass of 71.7 ± 6.3 M_{Jupiter}. We also used the TRADES code to simultaneously model both our RV measurements and the existing transit-timing measurements. We derived a mass of K2-19b of 59.5^{+7.2} _{-11.4} M_{Jupiter} and of K2-19c of 9.7 ^{+3.9} _{-2.0} M_{oplus}. A prior K2-19b mass estimated by Barros et al. (2015), based exclusively on transit timing measurements, is only consistent with our combined TTV and RV analysis, but not with our analysis based purely on RV measurements. K2-19b supports the suspicion that planet masses and densities involving TTV data are systematically lower than those based purely on RV measurements.

  2. Measurement of pulmonary transit time in healthy cats by use of ultrasound contrast media "Sonovue®": feasibility, reproducibility, and values in 42 cats.

    Science.gov (United States)

    Streitberger, Andrea; Hocke, Verena; Modler, Peter

    2013-09-01

    To evaluate the feasibility of measuring pulmonary transit time (PTT) in healthy cats by transthoracic echocardiography using the ultrasound contrast agent Sonovue(®). To determine normalized PTT (nPTT) values in 42 healthy cats and to estimate the interobserver variability and the within-day repeatability of nPTT measurements. Forty-two privately owned healthy cats of different breeds, gender and age presented for cardiac examination. A bolus injection of contrast agent (Sonovue(®)) was administered intravenously. The right parasternal short axis echocardiographic view was used to record the contrast agent's transit time from the pulmonary artery to the left atrium. Pulmonary transit time and nPTT were determined independently by three examiners with different levels of experience. Normalized PTT was 4.12 ± 1.0 (mean ± SD) in our population. The median interobserver variability across our population was 6.8%, the median within-day variability for the three observers were 13.1%, 12.7% and 13%. No effect of the observer's experience on nPTT measurement was identified. Age, sex and body weight did not significantly influence nPTT. This study demonstrates that nPTT measurement is feasible in cats using ultrasound and the blood pool contrast media Sonovue(®). Measurements of nPTT can be performed in a clinical setting. Normalized PTT values in healthy cats are comparable with those reported in healthy dogs. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Research on Operation Assessment Method for Energy Meter

    Science.gov (United States)

    Chen, Xiangqun; Huang, Rui; Shen, Liman; chen, Hao; Xiong, Dezhi; Xiao, Xiangqi; Liu, Mouhai; Xu, Renheng

    2018-03-01

    The existing electric energy meter rotation maintenance strategy regularly checks the electric energy meter and evaluates the state. It only considers the influence of time factors, neglects the influence of other factors, leads to the inaccuracy of the evaluation, and causes the waste of resources. In order to evaluate the running state of the electric energy meter in time, a method of the operation evaluation of the electric energy meter is proposed. The method is based on extracting the existing data acquisition system, marketing business system and metrology production scheduling platform that affect the state of energy meters, and classified into error stability, operational reliability, potential risks and other factors according to the influencing factors, based on the above basic test score, inspecting score, monitoring score, score of family defect detection. Then, according to the evaluation model according to the scoring, we evaluate electric energy meter operating state, and finally put forward the corresponding maintenance strategy of rotation.

  4. De Minimis Thresholds for Federal Building Metering Appropriateness

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Jordan W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-31

    The U.S. Department of Energy (DOE) is required by statute and Presidential Memorandum to establish guidelines for agencies to meter their Federal buildings for energy (electricity, natural gas, and steam) and water. See 42 U.S.C. § 8253(e). DOE issued guidance in February 2006 on the installation of electric meters in Federal buildings. A recent update to the 2006 guidance accounts for more current metering practices within the Federal Government. The updated metering guidance specifies that all Federal buildings shall be considered “appropriate” for energy or water metering unless identified for potential exclusion. In developing the updated guidance to carry out the statue, Congress also directed DOE to (among other things) establish exclusions from the metering requirements based on the de minimis quantity of energy use of a Federal building, industrial process, or structure. This paper discusses the method used to identify de minimis values.

  5. Advanced Metering Installations – A Perspective from Federal Sites

    Energy Technology Data Exchange (ETDEWEB)

    Earni, Shankar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area

    2016-05-02

    This report is intended to provide guidance to the United States Department of Energy (DOE) and other federal agencies to highlight some of the existing practices related to advanced building metering systems. This study identified some of the existing actions related to advanced meter data and proposes how advanced metered data can be employed to develop robust cost effective measurement and verification (M&V) strategies. This report proposes an integrated framework on how advanced meter data can be used to identify energy conservation opportunities and to develop proactive M&V strategies to ensure that the savings for energy projects are being realized. This information will help improve metering, feedback, and dashboard implementations for reducing energy use at DOE facilities, based on lessons learned from various advanced metering implementations.

  6. Method and apparatus for reading meters from a video image

    Science.gov (United States)

    Lewis, Trevor J.; Ferguson, Jeffrey J.

    1997-01-01

    A method and system to enable acquisition of data about an environment from one or more meters using video images. One or more meters are imaged by a video camera and the video signal is digitized. Then, each region of the digital image which corresponds to the indicator of the meter is calibrated and the video signal is analyzed to determine the value indicated by each meter indicator. Finally, from the value indicated by each meter indicator in the calibrated region, a meter reading is generated. The method and system offer the advantages of automatic data collection in a relatively non-intrusive manner without making any complicated or expensive electronic connections, and without requiring intensive manpower.

  7. Deducing Energy Consumer Behavior from Smart Meter Data

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Heick, Rune; Jacobsen, Rune Hylsberg

    2017-01-01

    The ongoing upgrade of electricity meters to smart ones has opened a new market of intelligent services to analyze the recorded meter data. This paper introduces an open architecture and a unified framework for deducing user behavior from its smart main electricity meter data and presenting...... the recognized home appliances. The framework uses open standard interfaces for exchanging data. The framework has been validated through comprehensive experiments that are related to an European Smart Grid project....

  8. [Hepatic transit times and liver elasticity compared with meld in predicting a 1 year adverse clinical outcome of a clinically diagnosed cirrhosis].

    Science.gov (United States)

    Koller, Tomáš; Piešťanská, Zuzana; Hlavatý, Tibor; Holomáň, Jozef; Glasa, Jozef; Payer, Juraj

    Hepatic transit times measured by the contrast enhanced ultrasonography and liver elasticity were found to predict a clinically significant portal hypertension. However, these modalities we not yet sufficiently evaluated in predicting adverse clinical outcome in patients with clinically diagnosed cirrhosis (D´Amico stages > 1), having a clinically significant portal hypertension. The aim of our study was to assess the predictive power of the liver transit times and the liver elasticity on an adverse clinical outcome of clinically diagnosed cirrhosis compared with the MELD score. The study group included 48 consecutive outpatients with cirrhosis in the 2., 3. and 4. DAmico stages. Patients with stage 4 could have jaundice, patients with other complications of portal hypertension were excluded. Transit times were measured from the time of intravenous administration of contrast agent (Sonovue) to a signal appearance in a hepatic vein (hepatic vein arrival time, HVAT) or time difference between the contrast signal in the hepatic artery and hepatic vein (hepatic transit time, HTT) in seconds. Elasticity was measured using the transient elastography (Fibroscan). The transit times and elasticity were measured at baseline and patients were followed for up for 1 year. Adverse outcome of cirrhosis was defined as the appearance of clinically apparent ascites and/or hospitalization for liver disease and/or death within 1 year. The mean age was 61 years, with female/male ratio 23/25. At baseline, the median Child-Pugh score was 5 (IQR 5.0-6.0), MELD 9.5 (IQR 7.6 to 12.1), median HVAT was 22 s (IQR 19-25) and HTT 6 (IQR 5-9). HTT and HVAT negatively correlated with Child-Pugh (-0.351 and -0.441, p = 0.002) and MELD (-0.479 and -0.388, p = 0.006) scores. The adverse outcome at 1-year was observed in 11 cases (22.9 %), including 6 deaths and 5 hospitalizations. Median HVAT in those with/without the adverse outcome was 20 seconds (IQR 19.3-23.5) compared with 22 s (IQR 19-26, p

  9. Calibration of ionization chamber and GM counter survey meters, (1)

    International Nuclear Information System (INIS)

    Bingo, Kazuyoshi; Kajimoto, Yoichi; Suga, Shin-ichi

    1978-01-01

    Three types of ionization chamber survey meters and a type of GM counter survey meter were calibrated for measuring the β-ray absorbed dose rate in a working area. To estimate the β-ray absorbed dose rate, a survey meter was used without and with a filter. A reading of survey meter's indicator measured with the filter was subtracted from a reading measured without the filter, and then the absorbed dose rate was obtained by multiplying this remainder by a conversion coefficient. The conversion coefficients were roughly constant with distance more than 8 cm (ionization chamber survey meters) and with distance more than 5 cm (GM counter survey meter). The conversion coefficient was dependent on β-ray energies. In order to measure the absorbed dose rate of tissue whose epidermal thickness is 40 mg/cm 2 , the constant value, 4 (mrad/h)/(mR/h), was chosen independently of β-ray energies as the conversion coefficient of three types of ionization chamber survey meters. The conversion coefficient of the GM counter survey meter was more energy dependent than that of every type of ionization chamber survey meter. (author)

  10. A Scalable Smart Meter Data Generator Using Spark

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem; Liu, Xiufeng; Danalachi, Sergiu

    2017-01-01

    Today, smart meters are being used worldwide. As a matter of fact smart meters produce large volumes of data. Thus, it is important for smart meter data management and analytics systems to process petabytes of data. Benchmarking and testing of these systems require scalable data, however, it can...... be challenging to get large data sets due to privacy and/or data protection regulations. This paper presents a scalable smart meter data generator using Spark that can generate realistic data sets. The proposed data generator is based on a supervised machine learning method that can generate data of any size...

  11. Collaborative Outbound Taxi Metering for Environmental Benefits, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the concept of Collaborative Outbound Taxi Metering (COTM), which provides environmental benefits without sacrificing throughput. In current...

  12. The design and commissioning of cold trap purifying system of hydrogen meter sodium loop

    International Nuclear Information System (INIS)

    Zhao Zhaoyi; Jia Baoshan; Chen Xiaoming; Pan Fengguo

    1993-01-01

    The design feature and parameters of cold trap purifying system of hydrogen meter sodium loop and its commissioning results are reported and discussed. In order to adjust the flow easily,. the cold trap purifying system is arranged in the exit of the electromagnetic pump. It is composed of regenerator and the cold trap. The regenerator is above the cold trap. The high temperature sodium in the main-loop flows through the regenerator, in the entrance of the cold trap, its temperature is reduced to 180 degree C. After entering into the cold trap, the sodium flows to the purifying region by side, when it arrives the bottom of the trap, its temperature is reduced to 110 degree C. The cold trap is cooled by air. The temperature of the clean sodium rises nearby the main-loop's by the regenerator, and then it returns to the entrance of the electromagnetic pump. According to the commissioning results, the sodium's temperature of the cold trap could be reduced to 110 degree C by reducing the flow of the cold trap purifying system and the temperature of the main-loop, or increasing the air flow and cutting off the power supply of its heating. The authors think that the latter is more conformable with the design stipulation and with the requirement of the hydrogen meter experiment, and it can meet the requirements of the operation of the Nuclear Power Plant

  13. Integrated Variable Speed Limits Control and Ramp Metering for Bottleneck Regions on Freeway

    Directory of Open Access Journals (Sweden)

    Ming-hui Ma

    2015-01-01

    Full Text Available To enhance the efficiency of the existing freeway system and therefore to mitigate traffic congestion and related problems on the freeway mainline lane-drop bottleneck region, the advanced strategy for bottleneck control is essential. This paper proposes a method that integrates variable speed limits and ramp metering for freeway bottleneck region control to relieve the chaos in bottleneck region. To this end, based on the analyses of spatial-temporal patterns of traffic flow, a macroscopic traffic flow model is extended to describe the traffic flow operating characteristic by considering the impacts of variable speed limits in mainstream bottleneck region. In addition, to achieve the goal of balancing the priority of the vehicles on mainline and on-ramp, increasing capacity, and reducing travel delay on bottleneck region, an improved control model, as well as an advanced control strategy that integrates variable speed limits and ramp metering, is developed. The proposed method is tested in simulation for a real freeway infrastructure feed and calibrates real traffic variables. The results demonstrate that the proposed method can substantially improve the traffic flow efficiency of mainline and on-ramp and enhance the quality of traffic flow at the investigated freeway mainline bottleneck.

  14. On Calibration of pH Meters

    Directory of Open Access Journals (Sweden)

    Da-Ming Zhu

    2005-04-01

    Full Text Available The calibration of pH meters including the pH glass electrode, ISE electrodes,buffers, and the general background for calibration are reviewed. Understanding of basicconcepts of pH, pOH, and electrode mechanism is emphasized. New concepts of pH, pOH,as well as critical examination of activity, and activity coefficients are given. Theemergence of new solid state pH electrodes and replacement of the salt bridge with aconducting wire have opened up a new horizon for pH measurements. A pH buffer solutionwith a conducting wire may be used as a stable reference electrode. The misleadingunlimited linear Nernstian slope should be discarded. Calibration curves with 3 nonlinearportions for the entire 0—14 pH range due to the isoelectric point change effect areexplained. The potential measurement with stirring or unstirring and effects by double layer(DL and triple layer (TL will be discussed.

  15. Recent patents in pressurised metered dose inhalers.

    Science.gov (United States)

    Ehtezazi, Touraj

    2012-04-01

    In this paper recent patents in pressurised metered dose inhalers have been reviewed. The patents are related to novel valves, dose-counters, formulations, add-on devices, reduction of propellant leakage and inkjet technology. Recently patented dose-counters provide mechanisms that are less susceptible to inaccuracy, and are battery-less electronic dose-counters with the help of miniature electromechanical generators. Regarding the formulation aspect, recent patents provide methods for combinational pMDIs and more stable products. Advantages of recently patented valves are being spring-free and less subject to loss of prime. Recent developments in micromachining have allowed patents that incorporate inkjet technology to develop inhalers that are similar to pMDIs, but produce uniform aerosol droplets. Coating canisters with suitable polymers has reduced need for excipients. Recently patented add-on devices reduce aerosol deposition in the spacer by creating turbulence on the walls of the chamber. Blockage of nozzles in actuators is prevented by providing tapered nozzle channels. In conclusion, these patents show better understanding of pMDIs and provide methods to achieve products with much improved reliability, aerosol performance and stability.

  16. Survey meter using novel inorganic scintillators

    International Nuclear Information System (INIS)

    Yoshikawa, Akira; Fukuda, Kentaro; Kawaguchi, Noriaki; Kamada, Kei; Fujimoto, Yutaka; Yokota, Yuui; Kurosawa, Shunsuke; Yanagida, Takayuki

    2012-01-01

    Single crystal scintillator materials are widely used for detection of high-energy photons and particles. There is continuous demand for new scintillator materials with higher performance because of increasing number of medical, industrial, security and other applications. This article presents the recent development of three novel inorganic scintillators; Pr-doped Lu 3 Al 5 O 12 (Pr:LuAG), Ce doped Gd 3 (Al, Ga) 5 O 12 (Ce:GAGG) and Ce or Eu-doped 6 LiCaAlF 6 (Ce:LiCAF, Eu:LiCAF). Pr:LuAG shows very interesting scintillation properties including very fast decay time, high light yield and excellent energy resolution. Taking the advantage of these properties, positron emission mammography (PEM) equipped with Pr:LuAG were developed. Ce:GAGG shows very high light yield, which is much higher than that of Ce:LYSO. Survey meter using Ce:GAGG is developed using this scintillator. Ce:LiCAF and Eu:LiCAF were developed for neutron detection. The advantage and disadvantage are discussed comparing with halide scintillators. Eu-doped LiCAF indicated five times higher light yield than that of existing Li-glass. It is expected to be used as the alternative of 3 He. (author)

  17. The time constrained multi-commodity network flow problem and its application to liner shipping network design

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Pisinger, David; Røpke, Stefan

    2015-01-01

    The multi-commodity network flow problem is an important sub-problem in several heuristics and exact methods for designing route networks for container ships. The sub-problem decides how cargoes should be transported through the network provided by shipping routes. This paper studies the multi......-commodity network flow problem with transit time constraints which puts limits on the duration of the transit of the commodities through the network. It is shown that for the particular application it does not increase the solution time to include the transit time constraints and that including the transit time...

  18. 40 CFR 89.416 - Raw exhaust gas flow.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Raw exhaust gas flow. 89.416 Section... Procedures § 89.416 Raw exhaust gas flow. The exhaust gas flow shall be determined by one of the methods...) Measurement of the air flow and the fuel flow by suitable metering systems (for details see SAE J244. This...

  19. Vascular Steal Explains Early Paradoxical Blood Oxygen Level-Dependent Cerebrovascular Response in Brain Regions with Delayed Arterial Transit Times

    Directory of Open Access Journals (Sweden)

    Julien Poublanc

    2013-04-01

    (p Conclusion: These results support the hypothesis that negative reactivity is the result of a steal phenomenon, lowering the BOLD signal as soon as healthier parts of the brain start to react and augment their blood flow. BOLD CVR MRI is capable of identifying this steal distribution, which has particular diagnostic significance as it represents an actual reduction in flow to already compromised tissue.

  20. Investigating water meter performance in developing countries: A ...

    African Journals Online (AJOL)

    2011-10-07

    Oct 7, 2011 ... real losses (leakage) or apparent (commercial) losses. Apparent losses occur due to illegal use, inaccuracies in metering, meter reading errors, data handling and billing errors, and have a negative impact on utility revenue and accuracy of water usage data (AWWA, 2009). One of the tools that has received ...