WorldWideScience

Sample records for calibrated pressure pulses

  1. Modeling transducer impulse responses for predicting calibrated pressure pulses with the ultrasound simulation program Field II

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2010-01-01

    FIELD II is a simulation software capable of predicting the field pressure in front of transducers having any complicated geometry. A calibrated prediction with this program is, however, dependent on an exact voltage-to-surface acceleration impulse response of the transducer. Such impulse respons...

  2. Pulse Pressure in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Jiri Parenica

    2012-02-01

    Full Text Available The review presents basic information about the pulse pressure. The variables related to pulse pressure are briefly explained - arterial stiffness, arterial compliance, pulse wave velocity, pulse pressure amplification and augmentation index. We present some recent trials and observational studies that show the importance of pulse pressure in clinical practice. Briefly the possibilities of influencing the pulse pressure are discussed.

  3. Pressures Detector Calibration and Measurement

    CERN Document Server

    AUTHOR|(CDS)2156315

    2016-01-01

    This is report of my first and second projects (of 3) in NA61. I did data taking and analysis in order to do calibration of pressure detectors and verified it. I analyzed the data by ROOT software using the C ++ programming language. The first part of my project was determination of calibration factor of pressure sensors. Based on that result, I examined the relation between pressure drop, gas flow rate of in paper filter and its diameter.

  4. Pulsed thrust measurements using electromagnetic calibration techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tang Haibin; Shi Chenbo; Zhang Xin' ai; Zhang Zun; Cheng Jiao [School of Astronautics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China)

    2011-03-15

    A thrust stand for accurately measuring impulse bits, which ranged from 10-1000 {mu}N s using a noncontact electromagnetic calibration technique is described. In particular, a permanent magnet structure was designed to produce a uniform magnetic field, and a multiturn coil was made to produce a calibration force less than 10 mN. The electromagnetic calibration force for pulsed thrust measurements was linear to the coil current and changed less than 2.5% when the distance between the coil and magnet changed 6 mm. A pulsed plasma thruster was first tested on the thrust stand, and afterward five single impulse bits were measured to give a 310 {mu}N s average impulse bit. Uncertainty of the measured impulse bit was analyzed to evaluate the quality of the measurement and was found to be 10 {mu}N s with 95% credibility.

  5. Calibration of pressure gauge for Cherenkov detector

    CERN Document Server

    Saponjic, Nevena

    2013-01-01

    Solartron/Hamilton pressure gauges are used to monitor the gas pressure in the particle beam detectors installed in the experimental areas. Here is description of the test bench for the calibration of these gauges in Labview.

  6. Probability based calibration of pressure coefficients

    DEFF Research Database (Denmark)

    Hansen, Svend Ole; Pedersen, Marie Louise; Sørensen, John Dalsgaard

    2015-01-01

    not depend on the type of variable action. A probability based calibration of pressure coefficients have been carried out using pressure measurements on the standard CAARC building modelled on scale of 1:383. The extreme pressures measured on the CAARC building model in the wind tunnel have been fitted...... to Gumbel distributions, and these fits are found to represent the data measured with good accuracy. The pressure distributions found have been used in a calibration of partial factors, which should achieve a certain theoretical target reliability index. For a target annual reliability index of 4.......3, the Eurocode partial factor of 1.5 for variable actions agrees well with the inherent uncertainties of wind actions when the pressure coefficients are determined using wind tunnel test results. The increased bias and uncertainty when pressure coefficients mainly are based on structural codes lead to a larger...

  7. Field mapping of ballistic pressure pulse sources

    Directory of Open Access Journals (Sweden)

    Rad Abtin Jamshidi

    2015-09-01

    Full Text Available Ballistic pressure pulse sources are used since late 1990s for the extracorporeal treatment of chronic Enthesitis. Newly indications are found in trigger-point-therapy for the treatment of musculoskeletal disorders. In both applications excellent results without relevant side effects were found in clinical trials. The technical principle of pressure pulse source is based on the same techniques used in air guns. A projectile is accelerated by pressurized air and hits the applicator with high kinetic energy. By this a compression wave travels through the material and induces a fast (4..5μs, almost singular pressure pulse of 2..10 MPa, which is followed by an equally short rarefaction phase of about the same amplitude. It is assumed that the pressure pulse accounts for the biomedical effects of the device. The slower inertial motion of the waveguide is damped by elastic stoppers, but still can be measured several micro seconds after the initial pressure pulse. In order to characterize the pressure pulse devices, field mapping is performed on several radial pressure pulse sources using the fiber optic hydrophone and a polyvinylidenfluorid (PVDF piezoelectric hydrophone. It could be shown that the current standard (IEC 61846 is not appropriate for characterization of ballistic pressure pulse sources.

  8. Calibrated Pulse-Thermography Procedure for Inspecting HDPE

    Directory of Open Access Journals (Sweden)

    Mohammed A. Omar

    2008-01-01

    Full Text Available This manuscript discusses the application of a pulse-thermography modality to evaluate the integrity of a high-density polyethylene HDPE joint for delamination, in nonintrusive manner. The inspected HDPE structure is a twin-cup shape, molded through extrusion, and the inspection system comprises a high-intensity, short-duration radiation pulse to excite thermal emission; the text calibrates the experiment settings (pulse duration, and detector sampling rate to accommodate HDPE bulks thermal response. The acquired thermal scans are processed through new contrast computation named “self-referencing”, to investigate the joint tensile strength and further map its adhesion interface in real-time. The proposed system (hardware, software combination performance is assessed through an ultrasound C-scan validation and further benchmarked using a standard pulse phase thermography (PPT routine.

  9. Bandpass calibration of a wideband spectrometer using pulse injection

    CERN Document Server

    Patra, Nipanjana; Ekers, Ron; Roberts, Paul

    2015-01-01

    We present a novel time domain concept for determining the bandpass response of a system by injecting a nanosecond pulse and capturing the system voltage output. A pulse of sub-nanosecond duration contains all frequency components with constant amplitude up to 1~GHz. Hence, this method can accurately determine the system bandpass response to a broadband signal. A train of pulses are coherently accumulated providing very high signal-to-noise calibration. The basic concept is demonstrated using a pulse generator-accumulator setup realised in a Bedlam board which is a high speed digital signal processing unit. The same system was used at the Parkes Radio Telescope between 2--13 October 2013 and we demonstrate its powerful diagnostic capability. We also present some initial test data from this experiment.

  10. Bandpass calibration of a wideband spectrometer using coherent pulse injection

    Science.gov (United States)

    Patra, Nipanjana; Bray, Justin D.; Roberts, Paul; Ekers, Ron D.

    2017-03-01

    We present a relatively simple time domain method for determining the bandpass response of a system by injecting a nanosecond pulse and capturing the system voltage output. A pulse of sub-nanosecond duration contains all frequency components with nearly constant amplitude up to 1 GHz. Hence, this method can accurately determine the system bandpass response to a broadband signal. In a novel variation on this impulse response method, a train of pulses is coherently accumulated providing precision calibration with a simple system. The basic concept is demonstrated using a pulse generator-accumulator setup realised in a Bedlam board which is a high speed digital signal processing unit. The same system was used at the Parkes radio telescope between 2-13 October 2013 and we demonstrate its powerful diagnostic capability. We also present some initial test data from this experiment.

  11. Characterisation of pulsed Carbon fiber illuminators for FIR instrument calibration

    CERN Document Server

    Henrot-Versillé, S; Couchot, F

    2007-01-01

    We manufactured pulsed illuminators emitting in the far infrared for the Planck-HFI bolometric instrument ground calibrations. Specific measurements have been conducted on these light sources, based on Carbon fibers, to understand and predict their properties. We present a modelisation of the temperature dependence of the thermal conductivity and the calorific capacitance of the fibers. A comparison between simulations and bolometer data is given, that shows the coherence of our model. Their small time constants, their stability and their emission spectrum pointing in the submm range make these illuminators a very usefull tool for calibrating FIR instruments.

  12. Device for calibration of low pressure gauges development

    OpenAIRE

    Nikitović Ž.D.

    2002-01-01

    Vacuum system set-up is presented and used for calibration of pressure gauges in the region of rough vacuum, from 103 mbar to 10-1 mbar, with dry air. The capacitance manometer is used for the calibration of piezoresistant manometer, oil, mercury and mercury micrometers U manometers. The applicability of the experimental set-up and obtained results for the low pressure gauges calibration in the medium and high vacuum region is approved. It was shown how calibration of some cheaper pressure ga...

  13. 40 CFR 1065.315 - Pressure, temperature, and dewpoint calibration.

    Science.gov (United States)

    2010-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Measurement of Engine...) Pressure. We recommend temperature-compensated, digital-pneumatic, or deadweight pressure calibrators, with... quantities that are NIST-traceable within 0.5% uncertainty. (2) Temperature. We recommend digital...

  14. Peristaltic pump-based low range pressure sensor calibration system.

    Science.gov (United States)

    Vinayakumar, K B; Naveen Kumar, G; Nayak, M M; Dinesh, N S; Rajanna, K

    2015-11-01

    Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.

  15. Pulse-based internal calibration of polarimetric SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Skou, Niels; Christensen, Erik Lintz

    1994-01-01

    Internal calibration greatly diminishes the dependence on calibration target deployment compared to external calibration. Therefore the Electromagnetics Institute (EMI) at the Technical University of Denmark (TUD) has equipped its polarimetric SAR, EMISAR, with several calibration loops and devel......Internal calibration greatly diminishes the dependence on calibration target deployment compared to external calibration. Therefore the Electromagnetics Institute (EMI) at the Technical University of Denmark (TUD) has equipped its polarimetric SAR, EMISAR, with several calibration loops...

  16. Underwater Calibration of Dome Port Pressure Housings

    Science.gov (United States)

    Nocerino, E.; Menna, F.; Fassi, F.; Remondino, F.

    2016-03-01

    Underwater photogrammetry using consumer grade photographic equipment can be feasible for different applications, e.g. archaeology, biology, industrial inspections, etc. The use of a camera underwater can be very different from its terrestrial use due to the optical phenomena involved. The presence of the water and camera pressure housing in front of the camera act as additional optical elements. Spherical dome ports are difficult to manufacture and consequently expensive but at the same time they are the most useful for underwater photogrammetry as they keep the main geometric characteristics of the lens unchanged. Nevertheless, the manufacturing and alignment of dome port pressure housing components can be the source of unexpected changes of radial and decentring distortion, source of systematic errors that can influence the final 3D measurements. The paper provides a brief introduction of underwater optical phenomena involved in underwater photography, then presents the main differences between flat and dome ports to finally discuss the effect of manufacturing on 3D measurements in two case studies.

  17. Cryogenic Pressure Calibration Facility Using a Cold Force Reference

    CERN Document Server

    Bager, T; Métral, L

    1999-01-01

    Presently various commercial cryogenic pressure sensors are being investigated for installation in the LHC collider, they will eventually be used to assess that the magnets are fully immersed in liquid and to monitor fast pressure transients. In the framework of this selection procedure a cryogenic pressue calibration facility has been designed and built; it is based on a cryogenic primary pressure reference made of a bellows that converts the pressure into a force measurement. For that a shaft transfers this force to a precision force transducer at room temperature. Knowing the liquid bath pessure and the surface area of the bellows the pressure applied to the transducers under calibration is calculated; corrections due to thermal contraction are introduced. To avoid loss of force in the bellows wall its length is maintained constant; a cold capacitive displacement sensor measures this. The calibration temperature covers 1.5 K to 4.2 K and the pressure 0 to 20 bar. In contrast with more classical techniques ...

  18. Two methods for absolute calibration of dynamic pressure transducers

    Science.gov (United States)

    Swift, G. W.; Migliori, A.; Garrett, S. L.; Wheatley, J. C.

    1982-12-01

    Two techniques are described for absolute calibration of a dynamic pressure transducer from 0 to 400 Hz in 1-MPa helium gas. One technique is based on a comparison to a mercury manometer; the other is based on the principle of reciprocity. The two techniques agree within the instrumental uncertainties of 1%.

  19. Characterization and calibration of the central arterial pressure waveform obtained from vibrocardiographic signal

    Science.gov (United States)

    Casacanditella, L.; Cosoli, G.; Casaccia, S.; Rohrbaugh, J. W.; Scalise, L.; Tomasini, E. P.

    2016-06-01

    Laser Doppler Vibrometry (LDV) has been demonstrated to be a non-contact technique with high sensitivity, able to measure the skin vibrations related to cardiac activity. The obtainable mechanical signal (i.e. a velocity signal), VibroCardioGram (VCG), is able to provide significant physiological parameters, such as Heart Rate (HR). In this work, the authors aim to present a non-contact measurement method to obtain the arterial blood pressure signal from the mechanical vibrations assessed by LDV, in a central district of the arterial tree, such as carotid artery. In fact, in this way it is possible to indirectly assess Central Arterial Blood Pressure (CABP), which indicates the hemodynamic load on the heart, so that it is considered an important index predicting the cardiac risk of a subject. The measurement setup involves the use of an oscillometric cuff, to measure peripheral blood pressure at the radial artery level. Diastolic and Mean Arterial Pressure (MAP) at radial level were used to calibrate the integrated LDV signal (i.e. a displacement signal). As regard calibration, an exponential mathematical model was adopted to derive the pressure waveform from the displacement of the vessel detected by LDV. Results show an average difference of around 20% between systolic pressure measured at brachial level (i.e. peripheral pressure value) and systolic pressure derived from VCG signal measured over the carotid artery (i.e. central pressure). This is a physiological difference, consistent with the literature about the physiological increase of Systolic Blood Pressure (SBP) and Pressure Pulse (PP) at increased distances from the heart. However, this non-contact technique is affected by movement artifacts and by reflection phenomena not related to the studied vessel and so it is necessary to account of such issues in the results.

  20. Cryogenic Pressure Calibrator for Wide Temperature Electronically Scanned (ESP) Pressure Modules

    Science.gov (United States)

    Faulcon, Nettie D.

    2001-01-01

    Electronically scanned pressure (ESP) modules have been developed that can operate in ambient and in cryogenic environments, particularly Langley's National Transonic Facility (NTF). Because they can operate directly in a cryogenic environment, their use eliminates many of the operational problems associated with using conventional modules at low temperatures. To ensure the accuracy of these new instruments, calibration was conducted in a laboratory simulating the environmental conditions of NTF. This paper discusses the calibration process by means of the simulation laboratory, the system inputs and outputs and the analysis of the calibration data. Calibration results of module M4, a wide temperature ESP module with 16 ports and a pressure range of +/- 4 psid are given.

  1. TRANSMISSION BEHAVIOR OF MUD-PRESSURE PULSE ALONG WELL BORE

    Institute of Scientific and Technical Information of China (English)

    LIU Xiu-shan; LI Bo; YUE Yu-quan

    2007-01-01

    In oil and gas industry, mud-pulse telemetry has been widely used to obtain directional data, drilling parameters, formation evaluation data and safety data, etc. Generally, the drilling mud in most current models was considered to be a single-phase fluid through which the mud pulses travel, despite the fact that the drilling mud is composed of two or more phases. In this article, a multiphase flow formula was proposed to calculate the mud-pulse velocity as mud solids and free-gas content change, and a mathematical model was put forward to simulate the dynamic-transmission behavior of the mud-pressure pulse or waves. Compared to conventional methods, the present model provides more accurate mud-pulse attenuation, and the dynamic-transmission behavior of drilling-mud pulses along well bores can also be easily examined. The model is valuable in improving the existing mud-pulse systems and developing new drilling-mud pulse systems.

  2. Absolute Calibration of Proportional Counter Based Fast Pulsed Neutron Detectors with Resolution Below 105 neutron/pulse

    Science.gov (United States)

    Tarifeño-Saldivia, A.; Mayer, R. E.; Pavez, C.; Soto, L.

    2014-05-01

    A method for absolute calibration of proportional counters for pulsed fast neutrons is presented. The method is based on the use of an isotopic standard source and development of a model for counting detected events from area of a signal compounded by single piled up neutron pulses. Effects of detection counting statistics and electrical background noise are also considered. The method is applied in detectors used for D-D neutron yield measurements in low emission plasma focus devices.

  3. On-Line Wavelength Calibration of Pulsed Laser for CO2 Differential Absorption LIDAR

    Science.gov (United States)

    Xiang, Chengzhi; Ma, Xin; Han, Ge; Liang, Ailin; Gong, Wei

    2016-06-01

    Differential absorption lidar (DIAL) remote sensing is a promising technology for atmospheric CO2 detection. However, stringent wavelength accuracy and stability are required in DIAL system. Accurate on-line wavelength calibration is a crucial procedure for retrieving atmospheric CO2 concentration using the DIAL, particularly when pulsed lasers are adopted in the system. Large fluctuations in the intensities of a pulsed laser pose a great challenge for accurate on-line wavelength calibration. In this paper, a wavelength calibration strategy based on multi-wavelength scanning (MWS) was proposed for accurate on-line wavelength calibration of a pulsed laser for CO2 detection. The MWS conducted segmented sampling across the CO2 absorption line with appropriate number of points and range of widths by using a tunable laser. Complete absorption line of CO2 can be obtained through a curve fitting. Then, the on-line wavelength can be easily found at the peak of the absorption line. Furthermore, another algorithm called the energy matching was introduced in the MWS to eliminate the backlash error of tunable lasers during the process of on-line wavelength calibration. Finally, a series of tests was conducted to elevate the calibration precision of MWS. Analysis of tests demonstrated that the MWS proposed in this paper could calibrate the on-line wavelength of pulsed laser accurately and steadily.

  4. 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.

  5. 33 CFR 159.111 - Pressure and vacuum pulse test.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Pressure and vacuum pulse test. 159.111 Section 159.111 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... vacuum pulse test. Liquid retention components of the device with manufacturer specified...

  6. Nuclear reactor pulse calibration using a CdZnTe electro-optic radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: knelson1@ksu.edu [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Geuther, Jeffrey A. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Neihart, James L.; Riedel, Todd A. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Rojeski, Ronald A. [Nanometrics, Inc., 1550 Buckeye Drive, Milpitas, CA 95035 (United States); Saddler, Jeffrey L. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Schmidt, Aaron J.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2012-07-15

    A CdZnTe electro-optic radiation detector was used to calibrate nuclear reactor pulses. The standard configuration of the Pockels cell has collimated light passing through an optically transparent CdZnTe crystal located between crossed polarizers. The transmitted light was focused onto an IR sensitive photodiode. Calibrations of reactor pulses were performed using the CdZnTe Pockels cell by measuring the change in the photodiode current, repeated 10 times for each set of reactor pulses, set between 1.00 and 2.50 dollars in 0.50 increments of reactivity. - Highlights: Black-Right-Pointing-Pointer We demonstrated the first use of an electro-optic device to trace reactor pulses in real-time. Black-Right-Pointing-Pointer We examined the changes in photodiode current for different reactivity insertions. Black-Right-Pointing-Pointer Created a linear best fit line from the data set to predict peak pulse powers.

  7. Influential factors for pressure pulse waveform in healthy young adults.

    Science.gov (United States)

    Du, Yi; Wang, Ling; Li, Shuyu; Zhi, Guang; Li, Deyu; Zhang, Chi

    2015-01-01

    The effects of gender and other contributory factors on pulse waveform are still under arguments. In view of different results caused by few considerations of possible influential factors and general agreement of gender relating to pulse waveform, this study aims to address the confounding factors interfering with the association between gender and pulse waveform characteristics. A novel method was proposed to noninvasively detect pressure pulse wave and assess the morphology of pulse wave. Forty healthy young subjects were included in the present research. Height, weight, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured manually and body mass index (BMI), pulse blood pressure (PP) and heart rate (HR) were calculated automatically. Student's t test was used to analyze the gender difference and analysis of variance (ANOVA) to examine the effects of intrinsic factors. Univariate regression analysis was performed to assess the main factors on the waveform characteristics. Waveform features were found significantly different between genders. However this study indicates that the main factors for time-related and amplitude-related parameters are HR and SBP respectively. In conclusion, the impact of HR and SBP on pulse waveform features should not be underestimated, especially when analyzing the gender difference.

  8. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    Wain, Louise V; Verwoert, Germaine C; O'Reilly, Paul F; Shi, Gang; Johnson, Toby; Johnson, Andrew D; Bochud, Murielle; Rice, Kenneth M; Henneman, Peter; Smith, Albert V; Ehret, Georg B; Amin, Najaf; Larson, Martin G; Mooser, Vincent; Hadley, David; Dörr, Marcus; Bis, Joshua C; Aspelund, Thor; Esko, Tõnu; Janssens, A Cecile J W; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian'an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U; Webster, Rebecca J; Zhang, Feng; Peden, John F; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hottenga, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I; Trompet, Stella; Bragg-Gresham, Jennifer L; Alizadeh, Behrooz Z; Chambers, John C; Guo, Xiuqing; Lehtimäki, Terho; Kühnel, Brigitte; Lopez, Lorna M; Polašek, Ozren; Boban, Mladen; Nelson, Christopher P; Morrison, Alanna C; Pihur, Vasyl; Ganesh, Santhi K; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco U S; Rivadeneira, Fernando; Sijbrands, Eric J G; Uitterlinden, Andre G; Hwang, Shih-Jen; Vasan, Ramachandran S; Wang, Thomas J; Bergmann, Sven; Vollenweider, Peter; Waeber, Gérard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Glazer, Nicole L; Taylor, Kent D; Harris, Tamara B; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Inês; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sõber, Siim; Lu, Xiaowen; Nolte, Ilja M; Penninx, Brenda W; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F; Melander, Olle; O'Donnell, Christopher J; Salomaa, Veikko; d'Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, Fabiola M; Facheris, Maurizio; Collins, Francis S; Bergman, Richard N; Beilby, John P; Hung, Joseph; Musk, A William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S; Navarro, Pau; Wild, Sarah H; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco J C; Willemsen, Gonneke; Parker, Alex N; Rose, Lynda M; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L; Kähönen, Mika; Viikari, Jorma; Döring, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H; Hoen, Peter A C 't; König, Inke R; Felix, Janine F; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Breteler, Monique; Debette, Stéphanie; Destefano, Anita L; Fornage, Myriam; Mitchell, Gary F; Smith, Nicholas L; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J; Wichmann, H-Erich; Raitakari, Olli T; Palmas, Walter; Kooner, Jaspal S; Stolk, Ronald P; Jukema, J Wouter; Wright, Alan F; Boomsma, Dorret I; Bandinelli, Stefania; Gyllensten, Ulf B; Wilson, James F; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D; Palmer, Lyle J; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth J F; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J; Oostra, Ben A; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P; Beckmann, Jacques S; Witteman, Jacqueline C M; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B; Psaty, Bruce M; Caulfield, Mark J; Rao, Dabeeru C; Tobin, Martin D; Elliott, Paul; van Duijn, Cornelia M

    2011-01-01

    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we ident

  9. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    Wain, Louise V.; Verwoert, Germaine C.; O'Reilly, Paul F.; Shi, Gang; Johnson, Toby; Johnson, Andrew D.; Bochud, Murielle; Rice, Kenneth M.; Henneman, Peter; Smith, Albert V.; Ehret, Georg B.; Amin, Najaf; Larson, Martin G.; Mooser, Vincent; Hadley, David; Doerr, Marcus; Bis, Joshua C.; Aspelund, Thor; Esko, Tonu; Janssens, A. Cecile J. W.; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian'an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U.; Webster, Rebecca J.; Zhang, Feng; Peden, John F.; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hottenga, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I.; Trompet, Stella; Bragg-Gresham, Jennifer L.; Alizadeh, Behrooz Z.; Chambers, John C.; Guo, Xiuqing; Lehtimaki, Terho; Kuehnel, Brigitte; Lopez, Lorna M.; Polasek, Ozren; Boban, Mladen; Nelson, Christopher P.; Morrison, Alanna C.; Pihur, Vasyl; Ganesh, Santhi K.; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco U. S.; Rivadeneira, Fernando; Sijbrands, Eric J. G.; Uitterlinden, Andre G.; Hwang, Shih-Jen; Vasan, Ramachandran S.; Wang, Thomas J.; Bergmann, Sven; Vollenweider, Peter; Waeber, Gerard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L.; Kroemer, Heyo K.; Voelker, Uwe; Voelzke, Henry; Glazer, Nicole L.; Taylor, Kent D.; Harris, Tamara B.; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Ines; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sober, Siim; Lu, Xiaowen; Nolte, Ilja M.; Penninx, Brenda W.; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F.; Melander, Olle; O'Donnell, Christopher J.; Salomaa, Veikko; d'Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, Fabiola M.; Facheris, Maurizio; Collins, Francis S.; Bergman, Richard N.; Beilby, John P.; Hung, Joseph; Musk, A. William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S.; Navarro, Pau; Wild, Sarah H.; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco J. C.; Willemsen, Gonneke; Parker, Alex N.; Rose, Lynda M.; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M.; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L.; Kahonen, Mika; Viikari, Jorma; Doering, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M.; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H.; 't Hoen, Peter A. C.; Koenig, Inke R.; Felix, Janine F.; Clarke, Robert; Hopewell, Jemma C.; Ongen, Halit; Breteler, Monique; Debette, Stephanie; DeStefano, Anita L.; Fornage, Myriam; Mitchell, Gary F.; Smith, Nicholas L.; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J.; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J.; Wichmann, H-Erich; Raitakari, Olli T.; Palmas, Walter; Kooner, Jaspal S.; Stolk, Ronald P.; Jukema, J. Wouter; Wright, Alan F.; Boomsma, Dorret I.; Bandinelli, Stefania; Gyllensten, Ulf B.; Wilson, James F.; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D.; Palmer, Lyle J.; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth J. F.; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J.; Oostra, Ben A.; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P.; Beckmann, Jacques S.; Witteman, Jacqueline C. M.; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M.; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R.; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B.; Psaty, Bruce M.; Caulfield, Mark J.; Rao, Dabeeru C.; Tobin, Martin D.; Elliott, Paul; van Duijn, Cornelia M.

    2011-01-01

    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans(1-3). We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we

  10. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    L.V. Wain (Louise); G.C. Verwoert (Germaine); P.F. O'Reilly (Paul); G. Shi (Gang); T. Johnson (Toby); M. Bochud (Murielle); K. Rice (Kenneth); P. Henneman (Peter); A.V. Smith (Albert Vernon); G.B. Ehret (Georg); N. Amin (Najaf); M.G. Larson (Martin); V. Mooser (Vincent); D. Hadley (David); M. Dörr (Marcus); J.C. Bis (Joshua); T. Aspelund (Thor); T. Esko (Tõnu); A.C.J.W. Janssens (Cécile); J.H. Zhao; S.C. Heath (Simon); M. Laan (Maris); J. Fu (Jingyuan); G. Pistis (Giorgio); J. Luan; G. Lucas (Gavin); N. Pirastu (Nicola); I. Pichler (Irene); A.U. Jackson (Anne); R.J. Webster (Rebecca J.); F.F. Zhang; J. Peden (John); R. Schmidt (Reinhold); T. Tanaka (Toshiko); H. Campbell (Harry); W. Igl (Wilmar); Y. Milaneschi (Yuri); J.J. Hottenga (Jouke Jan); V. Vitart (Veronique); D.I. Chasman (Daniel); S. Trompet (Stella); J.L. Bragg-Gresham (Jennifer L.); B.Z. Alizadeh (Behrooz); J.C. Chambers (John); X. Guo (Xiuqing); T. Lehtimäki (Terho); B. Kuhnel (Brigitte); L.M. Lopez; O. Polasek (Ozren); M. Boban (Mladen); C.P. Nelson (Christopher P.); A.C. Morrison (Alanna); V. Pihur (Vasyl); S.K. Ganesh (Santhi); A. Hofman (Albert); S. Kundu (Suman); F.U.S. Mattace Raso (Francesco); F. Rivadeneira Ramirez (Fernando); E.J.G. Sijbrands (Eric); A.G. Uitterlinden (André); S.J. Hwang; R.S. Vasan (Ramachandran Srini); Y.A. Wang (Ying); S.M. Bergmann (Sven); P. Vollenweider (Peter); G. Waeber (Gérard); J. Laitinen (Jaana); A. Pouta (Anneli); P. Zitting (Paavo); W.L. McArdle (Wendy); H.K. Kroemer (Heyo); U. Völker (Uwe); H. Völzke (Henry); N.L. Glazer (Nicole); K.D. Taylor (Kent); T.B. Harris (Tamara); H. Alavere (Helene); T. Haller (Toomas); A. Keis (Aime); M.L. Tammesoo; Y.S. Aulchenko (Yurii); K-T. Khaw (Kay-Tee); P. Galan (Pilar); S. Hercberg (Serge); G.M. Lathrop (Mark); S. Eyheramendy (Susana); E. Org (Elin); S. Sõber (Siim); X. Lu (Xiaowen); I.M. Nolte (Ilja); B.W.J.H. Penninx (Brenda); T. Corre (Tanguy); C. Masciullo (Corrado); C. Sala (Cinzia); L. Groop (Leif); B.F. Voight (Benjamin); O. Melander (Olle); C.J. O'Donnell (Christopher); V. Salomaa (Veikko); P. d' Adamo (Pio); A. Fabretto (Antonella); F. Faletra (Flavio); S. Ulivi (Shelia); F. Del Greco M (Fabiola); M.F. Facheris (Maurizio); F.S. Collins (Francis); R.N. Bergman (Richard); J.P. Beilby (John); J. Hung (Judy); A.W. Musk (Arthur); M. Mangino (Massimo); S.Y. Shin (So Youn); N. Soranzo (Nicole); H. Watkins (Hugh); A. Goel (Anuj); A. Hamsten (Anders); P. Gider (Pierre); M. Loitfelder (Marisa); M. Zeginigg (Marion); D.G. Hernandez (Dena); S.S. Najjar (Samer); P. Navarro (Pau); S.H. Wild (Sarah); A.M. Corsi (Anna Maria); A. Singleton (Andrew); E.J.C. de Geus (Eco); G.A.H.M. Willemsen (Gonneke); A.N. Parker (Alex); L.M. Rose (Lynda); B.M. Buckley (Brendan M.); D.J. Stott (David. J.); M. Orrù (Marco); M. Uda (Manuela); M.M. van der Klauw (Melanie); X. Li (Xiaohui); J. Scott (James); Y.D.I. Chen (Yii-Der Ida); G.L. Burke (Greg); M. Kähönen (Mika); J. Viikari (Jorma); A. Döring (Angela); T. Meitinger (Thomas); G.S. Davis; J.M. Starr (John); V. Emilsson (Valur); A.S. Plump (Andrew); J.H. Lindeman (Jan H.); P.A.C. 't Hoen (Peter); I.R. König (Inke); J.F. Felix (Janine); R. Clarke; J. Hopewell; H. Ongen (Halit); M.M.B. Breteler (Monique); S. Debette (Stéphanie); A.L. DeStefano (Anita); M. Fornage (Myriam); G.F. Mitchell (Gary); H. Holm (Hilma); K. Stefansson (Kari); G. Thorleifsson (Gudmar); U. Thorsteinsdottir (Unnur); N.J. Samani (Nilesh); M. Preuss (Michael); I. Rudan (Igor); C. Hayward (Caroline); I.J. Deary (Ian); H.E. Wichmann (Heinz Erich); O. Raitakari (Olli); W. Palmas (Walter); J.S. Kooner (Jaspal); R.P. Stolk (Ronald); J.W. Jukema (Jan Wouter); A.F. Wright (Alan); D.I. Boomsma (Dorret); S. Bandinelli (Stefania); U. Gyllensten (Ulf); J.F. Wilson (James); L. Ferrucci (Luigi); M. Farrall (Martin); T.D. Spector (Timothy); L.J. Palmer; J. Tuomilehto (Jaakko); A. Pfeufer (Arne); P. Gasparini (Paolo); D.S. Siscovick (David); D. Altshuler (David); R.J.F. Loos (Ruth); D. Toniolo (Daniela); H. Snieder (Harold); C. Gieger (Christian); P. Meneton (Pierre); N.J. Wareham (Nick); B.A. Oostra (Ben); A. Metspalu (Andres); L.J. Launer (Lenore); R. Rettig (Rainer); D.P. Strachan (David); J.S. Beckmann (Jacques); J.C.M. Witteman (Jacqueline); J.A.P. Willems van Dijk (Ko); E.A. Boerwinkle (Eric); M. Boehnke (Michael); P.M. Ridker (Paul); M.R. Järvelin; A. Chakravarti (Aravinda); J. Erdmann (Jeanette); V. Gudnason (Vilmundur); C. Newton-Cheh (Christopher); D. Levy (Daniel); P. Arora (Pankaj); P. Munroe (Patricia); B.M. Psaty (Bruce); M. Caulfield (Mark); D.C. Rao (Dabeeru C.); P. Elliott (Paul); P. Tikka-Kleemola (Päivi); G.R. Abecasis (Gonçalo); I. Barroso (Inês)

    2011-01-01

    textabstractNumerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,60

  11. Understanding the ATLAS electromagnetic barrel pulse shapes and the absolute electronic calibration

    CERN Document Server

    Neukermans, L; Zitoun, R

    2001-01-01

    We present an original method to undestand the calibration and physics pulse shapes collected in the 2000 barrel test beam runs with the prototype module. It is based on an electrical description of the calorimeter and its electronics. It allows an understanding of the physics pulse shapes and its absolute calibration (in microA/ADC) to a very good level of accuracy with a small number of parameters (capacitances and inductances). The electrical parameters found by this method agree with the direct measurements independantly performed on the prototype module. Optimal filtering coefficients can then be derived from these physics pulse shape predictions, and more crucial, an absolute electronic calibration. These coefficients are released in the official test beam software EMTB.

  12. Ozone formation in pulsed SDBD in a wide pressure range

    Science.gov (United States)

    Starikovskiy, Andrey; Nudnova, Maryia; mipt Team

    2011-10-01

    Ozone concentration in surface anode-directed DBD for wide pressure range (150 - 1300 torr) was experimentally measured. Voltage and pressure effect were investigated. Reduced electric field was measured for anode-directed and cathode-directed SDBD. E/n values in cathode-directed SDBD is higher than in cathode-directed on 50 percent at atmospheric pressure. E/n value increase leads to decrease the rate of oxygen dissociation and Ozone formation at lower pressures. Radiating region thickness of sliding discharge was measured. Typical thickness of radiating zone is 0.4-1.0 mm within pressure range 220-740 torr. It was shown that high-voltage pulsed nanosecond discharge due to high E/n value produces less Ozone with compare to other discharges. Kinetic model was proposed to describe Ozone formation in the pulsed nanosecond SDBD.

  13. Pulsed pressure treatment for inactivation of escherichia coli and listeria innocua in whole milk

    Energy Technology Data Exchange (ETDEWEB)

    Buzrul, S; Largeteau, A; Demazeau, G [ICMCB, CNRS, Universite Bordeaux 1, site de l' ENSCPB, 87 avenue du Dr. A. Schweitzer, 33608 PESSAC cedex (France); Alpas, H [Food Engineering Department, Middle East Technical University, 06531, Ankara (Turkey)], E-mail: sbuzrul@metu.edu.tr

    2008-07-15

    E. coli and L. innocua in whole milk were subjected to continuous pressure treatments (300, 350, 400, 450, 500, 550 and 600 MPa) at ambient temperature for 5, 10, 15 and 20 min. These treatments underlined that at moderate pressure values (300, 350 and 400 MPa), increasing the pressurization time from 5 to 20 min did not improve cell death to a great extent. Therefore, pulsed pressure treatments (at 300, 350 and 400 MPa) for 5 min (2.5 min x 2 pulses, 1 min x 5 pulses and 0.5 min x 10 pulses), 10 min (5 min x 2 pulses, 2 min x 5 pulses and 1 min x 10 pulses), 15 min (5 min x 3 pulses, 3 min x 5 pulses and 1.5 min x 10 pulses) and 20 min (10 min x 2 pulses, 5 min x 4 pulses, 4 min x 5 pulses and 2 min x 10 pulses) were applied. As already observed in continuous pressure experiments, in pulsed pressure treatments the inactivation level is improved with increasing pressure level and in addition with the number of applied pulses; however, the effect of pulse number is not additive. Results obtained in this study indicated that pulsed pressure treatments could be used to pasteurize the whole milk at lower pressure values than the continuous pressure treatments. Nevertheless, an optimization appears definetely necessary between the number of pulses and pressure levels to reach the desirable number of log-reduction of microorganisms.

  14. Tensile Strength of Water Exposed to Pressure Pulses

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Mørch, Knud Aage

    2012-01-01

    It is well known that pressurization for an extended period of time increases the tensile strength of water, but little information is available on the effect of pressure pulses of short duration. This is addressed in the present paper where we first measure the tensile strength of water at an ex...... the compressive pulse, but the effect is shortlived. We presume that diffusion of non-condensable gas from the cavitation nuclei into the liquid at compression, and back again later, is responsible for the changes of tensile strength....

  15. Development of a Calibration and Monitoring System for GD-1 High Pressure Common Rail Diesel Engine

    Institute of Scientific and Technical Information of China (English)

    王俊席; 杨林; 冯静; 冒晓建; 卓斌

    2004-01-01

    Based on CAN calibration protocol, a new calibration and monitoring system was developed for the GD1 high pressure common rail diesel engine. CAN driver block, monitoring program and calibration program for this system were designed respectively. The inquiry mode was used in the monitoring program and the interrupt mode was used in calibration program. The calibration program was designed in structural programming model. This system provides a reliable, accurate and quick CAN bus between ECU and PC, with baud rate up to 500Kbit/s.The implementation of the compatible and universal CAN calibration protocol makes it easy to displace the system and its function modules. It also provides friendly, compatible and flexible calibration interface, and the functions of online calibration and real-time monitoring. This system was successfully used in a GD-1 high pressure common rail diesel engine and the engine performance and exhaust emissions were significantly improved.

  16. Non-Contact Thrust Stand Calibration Method for Repetitively-Pulsed Electric Thrusters

    Science.gov (United States)

    Wong, Andrea R.; Toftul, Alexandra; Polzin, Kurt A.; Pearson, J. Boise

    2011-01-01

    A thrust stand calibration technique for use in testing repetitively-pulsed electric thrusters for in-space propulsion has been developed and tested using a modified hanging pendulum thrust stand. In the implementation of this technique, current pulses are applied to a solenoidal coil to produce a pulsed magnetic field that acts against the magnetic field produced by a permanent magnet mounted to the thrust stand pendulum arm. The force on the magnet is applied in this non-contact manner, with the entire pulsed force transferred to the pendulum arm through a piezoelectric force transducer to provide a time-accurate force measurement. Modeling of the pendulum arm dynamics reveals that after an initial transient in thrust stand motion the quasisteady average deflection of the thrust stand arm away from the unforced or zero position can be related to the average applied force through a simple linear Hooke s law relationship. Modeling demonstrates that this technique is universally applicable except when the pulsing period is increased to the point where it approaches the period of natural thrust stand motion. Calibration data were obtained using a modified hanging pendulum thrust stand previously used for steady-state thrust measurements. Data were obtained for varying impulse bit at constant pulse frequency and for varying pulse frequency. The two data sets exhibit excellent quantitative agreement with each other as the constant relating average deflection and average thrust match within the errors on the linear regression curve fit of the data. Quantitatively, the error on the calibration coefficient is roughly 1% of the coefficient value.

  17. Pulse Radiolysis at High Temperatures and High Pressures

    DEFF Research Database (Denmark)

    Christensen, H.; Sehested, Knud

    1981-01-01

    A set-up enabling pulse radiolysis measurements at high temperatures (up to 320°C) and high pressures (up to 140 bar) has been constructed in collaboration between Risö National Laboratory and Studsvik Energiteknik. The cell has been used for experiments with aqueous solutions with the purpose...

  18. A Volt-Second Source for Calibration of Integrator in a Pulsed Field Magnetometer

    Institute of Scientific and Technical Information of China (English)

    LIN An-Li; HE Jian; ZHANG Yue; John Dudding; Michael Hall

    2007-01-01

    A volt-second (Vs) source intended for absolutely calibrating the integrator in a pulsed field magnetometer (PFM) is designed and proven to be with accurate rising and falling edges and reasonable lower uncertainty. A comparison experiment shows that the difference between the magnetic fluxes generated respectively by the Vs source and the mutual inductor is within ±0.04%. The PFM is then calibrated in an absolute way of the Vs source. The calibrated PFM gives the measured results in good agreement with a static BH tracer supplied by National Institute of Metrology of China and provides a convenient way of studying the effect of mathematic process on the dynamic measuring curve of PFMs.

  19. Digital pressure ulcer after pulse oximetry [Digitales Druckulkus nach Pulsoxymetrie

    Directory of Open Access Journals (Sweden)

    Zeplin, Philip H.

    2013-06-01

    Full Text Available [english] In emergency medical service, in intensive care unit and anaesthesia oxygenation is monitored with pulse oximetry apparatus. Pulse oximetry probe is usually attached to the finger, toe or earlobe. To the best of our knowledge this is the first case report describing the occurrence of a pressure ulcer after finger pulse oximetry measurement.[german] Sowohl in der Notfall- und Intensivmedizin als auch in der Anästhesie wird die Sauerstoffsättigung des Blutes mit Pulsoxymetern ermittelt. Diese Pulsoxymeter werden üblicherweise an den Fingern, den Zehen oder dem Ohrläppchen angebracht. Wir beschreiben einen Fall, bei dem es nach Anlage eines Fingerclip-Pulsoxymeters zur Ausbildung eines operationsbedürftigen Druckulkus kam.

  20. Novel Method for Processing the Dynamic Calibration Signal of Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Zhongyu Wang

    2015-07-01

    Full Text Available Dynamic calibration is one of the important ways to acquire the dynamic performance parameters of a pressure sensor. This research focuses on the processing method for the output of calibrated pressure sensor, and mainly attempts to solve the problem of extracting the true information of step response under strong interference noise. A dynamic calibration system based on a shock tube is established to excite the time-domain response signal of a calibrated pressure sensor. A key processing on difference modeling is applied for the obtained signal, and several generating sequences are established. A fusion process for the generating sequences is then undertaken, and the true information of the step response of the calibrated pressure sensor can be obtained. Finally, by implementing the common QR decomposition method to deal with the true information, a dynamic model characterizing the dynamic performance of the calibrated pressure sensor is established. A typical pressure sensor was used to perform calibration tests and a frequency-domain experiment for the sensor was also conducted. Results show that the proposed method could effectively filter strong interference noise in the output of the sensor and the corresponding dynamic model could effectively characterize the dynamic performance of the pressure sensor.

  1. Novel Method for Processing the Dynamic Calibration Signal of Pressure Sensor.

    Science.gov (United States)

    Wang, Zhongyu; Li, Qiang; Wang, Zhuoran; Yan, Hu

    2015-07-21

    Dynamic calibration is one of the important ways to acquire the dynamic performance parameters of a pressure sensor. This research focuses on the processing method for the output of calibrated pressure sensor, and mainly attempts to solve the problem of extracting the true information of step response under strong interference noise. A dynamic calibration system based on a shock tube is established to excite the time-domain response signal of a calibrated pressure sensor. A key processing on difference modeling is applied for the obtained signal, and several generating sequences are established. A fusion process for the generating sequences is then undertaken, and the true information of the step response of the calibrated pressure sensor can be obtained. Finally, by implementing the common QR decomposition method to deal with the true information, a dynamic model characterizing the dynamic performance of the calibrated pressure sensor is established. A typical pressure sensor was used to perform calibration tests and a frequency-domain experiment for the sensor was also conducted. Results show that the proposed method could effectively filter strong interference noise in the output of the sensor and the corresponding dynamic model could effectively characterize the dynamic performance of the pressure sensor.

  2. Pulse Radiolysis at High Temperatures and High Pressures

    DEFF Research Database (Denmark)

    Christensen, H.; Sehested, Knud

    1980-01-01

    A cell for pulse radiolytic measurements up to temperatures of 320°C and pressures of 14 MPa is constructed. The activation energy of the reaction OH + Cu2+ is determined to 13.3 kJ × mol−1 (3.2 kcal × mol−1). A preliminary study of the reaction e−aq + e−aq yields an activation energy of 22 kJ × ...

  3. FEASIBILITY STUDY OF PRESSURE PULSING PIPELINE UNPLUGGING TECHNOLOGIES FOR HANFORD

    Energy Technology Data Exchange (ETDEWEB)

    Servin, M. A. [Washington River Protection Solutions, LLC, Richland, WA (United States); Garfield, J. S. [AEM Consulting, LLC (United States); Golcar, G. R. [AEM Consulting, LLC (United States)

    2012-12-20

    The ability to unplug key waste transfer routes is generally essential for successful tank farms operations. All transfer lines run the risk of plugging but the cross site transfer line poses increased risk due to its longer length. The loss of a transfer route needed to support the waste feed delivery mission impacts the cost and schedule of the Hanford clean up mission. This report addresses the engineering feasibility for two pressure pulse technologies, which are similar in concept, for pipeline unplugging.

  4. Treatment of chronic rhinosinusitis with pressure-pulsed corticosteroid inhalation.

    Science.gov (United States)

    Goektas, Oender; Lau, Larissa; Olze, Heidi

    2013-08-01

    Chronic rhinosinusitis may cause olfactory dysfunction and affects quality of life in patients. In a prospective study we investigated the effect of topical application of corticosteroids through pressure-pulsed inhalation as treatment option of chronic rhinosinusitis with olfactory disorder. Patients with sinonasal olfactory disorder according to the European Position Paper on Rhinosinusitis and Nasal Polyps (EP3OS) were allocated to the new nasal inhalation therapy or a systemic corticosteroid therapy, each receiving a corticosteroid course of 12 days. 18 patients received topical corticosteroid pressure-pulsed inhalation (AMSA, Schumacher, Dausenau) and 15 systemic corticosteroid. Olfactory function was measured before and after treatment using the Threshold Discrimination Identification score (TDI score) and visual analogue scales. Lund Mackay score (LMS) was measured before starting treatment. Olfactory function (OF) increased from 17.5 ± 6.4 to 21 ± 7.9 TDI points (p treatment after 2 months. In the follow-up period of 6 months, the mean TDI score dropped to 20.0 ± 9.2 points (p = 0.01). There was no correlation between LMS and TDI. Treatment of chronic rhinosinusitis with pressure-pulsed inhalation was demonstrated to be effective. Multicenter investigations with large participant numbers are needed.

  5. Simulations of piezoelectric pressure sensor for radial artery pulse measurement

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Abhay B. [Department of Electronic Science, University of Pune, Pune 411 007 (India); Kalange, Ashok E. [Department of Electronic Science, University of Pune, Pune 411 007 (India); Tuljaram Chaturchand College, Baramati 413 102 (India); Bodas, Dhananjay, E-mail: dhananjay.bodas@gmail.co [Center for Nanobio Sciences, Agharkar Research Institute, Pune 411 004 (India); Gangal, S.A. [Department of Electronic Science, University of Pune, Pune 411 007 (India)

    2010-04-15

    A radial artery pulse is used to diagnose human body constitution (Prakruti) in Ayurveda. A system consisting of piezoelectric sensor (22 mm x 12 mm), data acquisition card and LabView software was used to record the pulse data. The pulse obtained from the sensor was noisy, even though signal processing was done. Moreover due to large sized senor accurate measurements were not possible. Hence, a need was felt to develop a sensor of the size of the order of finger tip with a resonant frequency of the order of 1 Hz. A micromachined pressure sensor based on piezoelectric sensing mechanism was designed and simulated using CoventorWare. Simulations were carried out by varying dimensions of the sensor to optimize the resonant frequency, stresses and voltage generated as a function of applied pressure. All simulations were done with pressure ranging of 1-30 kPa, which is the range used by Ayurvedic practitioners for diagnosis. Preliminary work on fabrication of such a sensor was carried out successfully.

  6. Waveform descriptor for pulse onset detection of intracranial pressure signal.

    Science.gov (United States)

    Yang, Li; Zhao, Mingxi; Peng, Chenglin; Hu, Xiao; Feng, Hua; Ji, Zhong

    2012-03-01

    We present an algorithm to identify the onset of intracranial pressure (ICP) pulses. The algorithm creates a waveform descriptor to extract the feature of each local minimum of the waveform and then identifies the onset by comparing the feature with a customized template. The waveform descriptor is derived by transforming the vectors connecting a given point and the local waveform samples around it into log-polar coordinates and ranking them into uniform bins. Using an ICP dataset consisting of 40933 normal beats and 306 segments of artifacts and noise, we investigated the performance of our algorithm (waveform descriptor, WD), global minimum within a sliding window (GM) and two other algorithms originally proposed for arterial blood pressure (ABP) signal (slope sum function, SSF and pulse waveform delineator, PUD). As a result, all the four algorithms showed good performance and WD showed overall better one. At a tolerance level of 30 ms (i.e., the predicted onset and ground truth were considered as correctly matched if the distance between the two was equal or less than 30 ms), WD achieved a sensitivity of 0.9723 and PPV of 0.9475, GM achieved a sensitivity of 0.9226 and PPV of 0.8968, PUD achieved a sensitivity of 0.9599 and PPV of 0.9327 and SSF, a sensitivity of 0.9720 and PPV of 0.9136. The evaluation indicates that the algorithms are effective for identifying the onset of ICP pulses.

  7. Importance of re-calibration time on pulse contour analysis agreement with thermodilution measurements of cardiac output: a retrospective analysis of intensive care unit patients.

    Science.gov (United States)

    Scully, Christopher G; Gomatam, Shanti; Forrest, Shawn; Strauss, David G

    2016-10-01

    We assessed the effect of re-calibration time on cardiac output estimation and trending performance in a retrospective analysis of an intensive care unit patient population using error grid analyses. Paired thermodilution and arterial blood pressure waveform measurements (N = 2141) from 222 patient records were extracted from the Multiparameter Intelligent Monitoring in Intensive Care II database. Pulse contour analysis was performed by implementing a previously reported algorithm at calibration times of 1, 2, 8 and 24 h. Cardiac output estimation agreement was assessed using Bland-Altman and error grid analyses. Trending was assessed by concordance and a 4-Quadrant error grid analysis. Error between pulse contour and thermodilution increased with longer calibration times. Limits of agreement were -1.85 to 1.66 L/min for 1 h maximum calibration time compared to -2.70 to 2.41 L/min for 24 h. Error grid analysis resulted in 74.2 % of points bounded by 20 % error limits of thermodilution measurements for 1 h calibration time compared to 65 % for 24 h. 4-Quadrant error grid analysis showed analysis method and thermodilution showed poor agreement to monitor changes in cardiac output.

  8. Vasodilation increases pulse pressure variation, mimicking hypovolemic status in rabbits

    Directory of Open Access Journals (Sweden)

    Glauco A Westphal

    2010-01-01

    Full Text Available OBJECTIVE: To test the hypothesis that pulse pressure respiratory variation (PPV amplification, observed in hypovolemia, can also be observed during sodium nitroprusside (SNP-induced vasodilation. INTRODUCTION: PPV is largely used for early identification of cardiac responsiveness, especially when hypovolemia is suspected. PPV results from respiratory variation in transpulmonary blood flow and reflects the left ventricular preload variations during respiratory cycles. Any factor that decreases left ventricular preload can be associated with PPV amplification, as seen in hypovolemia. METHODS: Ten anesthetized and mechanically ventilated rabbits underwent progressive hypotension by either controlled hemorrhage (Group 1 or intravenous SNP infusion (Group 2. Animals in Group 1 (n = 5 had graded hemorrhage induced at 10% steps until 50% of the total volume was bled. Mean arterial pressure (MAP steps were registered and assumed as pressure targets to be reached in Group 2. Group 2 (n = 5 was subjected to a progressive SNP infusion to reach similar pressure targets as those defined in Group 1. Heart rate (HR, systolic pressure variation (SPV and PPV were measured at each MAP step, and the values were compared between the groups. RESULTS: SPV and PPV were similar between the experimental models in all steps (p > 0.16. SPV increased earlier in Group 2. CONCLUSION: Both pharmacologic vasodilation and graded hemorrhage induced PPV amplification similar to that observed in hypovolemia, reinforcing the idea that amplified arterial pressure variation does not necessarily represent hypovolemic status but rather potential cardiovascular responsiveness to fluid infusion.

  9. Multi-Pulsed High Hydrostatic Pressure Treatment of Foods

    Directory of Open Access Journals (Sweden)

    Sencer Buzrul

    2015-05-01

    Full Text Available Multi-pulsed high hydrostatic pressure (mpHHP treatment of foods has been investigated for more than two decades. It was reported that the mpHHP treatment, with few exceptions, is more effective than the classical or single-pulsed HHP (spHHP treatment for inactivation of microorganisms in fruit juice, dairy products, liquid whole egg, meat products, and sea foods. Moreover, the mpHHP treatment could be also used to inactivate enzymes in foods and to increase the shelf-life of foods. The effects of the mpHHP treatment of foods are summarized and the differences between the mpHHP and spHHP are also emphasized.

  10. Phase calibration of sonar systems using standard targets and dual-frequency transmission pulses.

    Science.gov (United States)

    Islas-Cital, Alan; Atkins, Philip R; Foo, Kae Y; Picó, Ruben

    2011-10-01

    The phase angle component of the complex frequency response of a sonar system operating near transducer resonance is usually distorted. Interpretation and classification of the received sonar signal benefits from the preservation of waveform fidelity over the full bandwidth. A calibration process that measures the phase response in addition to the amplitude response is thus required. This paper describes an extension to the standard-target calibration method to include phase angle, without affecting the experimental apparatus, by using dual-frequency transmission pulses and frequency-domain data processing. This approach reduces the impact of unknown range and sound speed parameters upon phase calibration accuracy, as target phase is determined from the relationship of the two frequency components instead of relying on a local phase reference. Tungsten carbide spheres of various sizes were used to simultaneously calibrate the amplitude and phase response of an active sonar system in a laboratory tank. Experimental measurements of target phase spectra are in good agreement with values predicted from a theoretical model based upon full-wave analysis, over an operating frequency of 50-125 kHz.

  11. Towards a shock tube method for the dynamic calibration of pressure sensors.

    Science.gov (United States)

    Downes, Stephen; Knott, Andy; Robinson, Ian

    2014-08-28

    In theory, shock tubes provide a pressure change with a very fast rise time and calculable amplitude. This pressure step could provide the basis for the calibration of pressure transducers used in highly dynamic applications. However, conventional metal shock tubes can be expensive, unwieldy and difficult to modify. We describe the development of a 1.4 MPa (maximum pressure) shock tube made from unplasticized polyvinyl chloride pressure tubing which provides a low-cost, light and easily modifiable basis for establishing a method for determining the dynamic characteristics of pressure sensors.

  12. Understanding Cavitation Intensity through Pitting and Pressure Pulse Analysis

    Science.gov (United States)

    Jayaprakash, A.; Singh, S.; Choi, J.-K.; Chahine, G.

    2011-11-01

    Cavitation erosion is of interest to the designers of ship propulsion devices because of its detrimental effects. One of the difficulties of predicting cavitation erosion is that the intensity of cavitation is not well predicted or defined. In this work we attempt to define the intensity of a cavitation erosion field through analysis of cavitation induced erosion pits and pressure pulses. In the pitting tests, material samples were subjected to cavitation field for a short duration of time selected within the test sample's incubation period, so that the test sample undergoes plastic deformation only. The sample material reacts to these cavitation events by undergoing localized permanent deformation, called pits. The resulting pitted sample surfaces were then optically scanned and analyzed. The pressure signals under cavitating jets and ultrasonic horns, for different conditions, were experimentally recorded using high frequency response pressure transducers. From the analysis of the pitting data and recorded pressure signals, we propose a model that describes the statistics, which in the future can be used to define the cavitation field intensity. Support for this work was provided by Office of Naval Research (ONR) under contract number N00014-08-C-0450, monitored by Dr. Ki-Han Kim.

  13. Association of adiposity with Pulse pressure amongst Gujarati Indian adolescents

    Directory of Open Access Journals (Sweden)

    Shaikh Wasim

    2010-01-01

    Full Text Available Background and Aim: The current study was conducted to determine the effect of adiposity on vascular distensibility in Gujarati Indian adolescents as research indicating the pathogenesis of hypertension among overweight and/or obese Indian adolescents is scant and ethnic differences exist in the pathogenesis of hypertension. Materials and Methods: A cross-sectional study was conducted on 488 Gujarati Indian adolescents of 16-19 years age group. Adiposity was assessed in terms of BMI, Body Fat %, Fat Mass, Fat Mass Index and Waist Circumference. Arterial blood pressure was recorded and pulse pressure (PP was calculated using the standard equation based on the difference between systolic blood pressure (SBP and diastolic blood pressure (DBP. Pearson′s correlation coefficient was determined to find the association between the markers of adiposity and SBP, DBP and PP. Result: A significant positive correlationship was found between adiposity and PP in boys. However, no significant correlationship was found between adiposity and PP in girls. Conclusion: An increase in total as well as visceral adiposity is probably associated with a decrease in vascular distensibility in the Gujarati Indian adolescent boys but not in girls, thus indicating a protective role of female sex hormone estrogen which has been shown earlier to protect the vasculature from atherosclerosis, endothelial dysfunction which occurs with increase in adiposity.

  14. Relationship between stroke volume and pulse pressure during blood volume perturbation: a mathematical analysis.

    Science.gov (United States)

    Bighamian, Ramin; Hahn, Jin-Oh

    2014-01-01

    Arterial pulse pressure has been widely used as surrogate of stroke volume, for example, in the guidance of fluid therapy. However, recent experimental investigations suggest that arterial pulse pressure is not linearly proportional to stroke volume. However, mechanisms underlying the relation between the two have not been clearly understood. The goal of this study was to elucidate how arterial pulse pressure and stroke volume respond to a perturbation in the left ventricular blood volume based on a systematic mathematical analysis. Both our mathematical analysis and experimental data showed that the relative change in arterial pulse pressure due to a left ventricular blood volume perturbation was consistently smaller than the corresponding relative change in stroke volume, due to the nonlinear left ventricular pressure-volume relation during diastole that reduces the sensitivity of arterial pulse pressure to perturbations in the left ventricular blood volume. Therefore, arterial pulse pressure must be used with care when used as surrogate of stroke volume in guiding fluid therapy.

  15. Modeling and calibration of pulse-modulation based ToF imaging systems

    Science.gov (United States)

    Süss, Andreas; Varga, Gabor; Marx, Michael; Fürst, Peter; Gläsener, Stefan; Tiedke, Wolfram; Jung, Melanie; Spickermann, Andreas; Hosticka, Bedrich J.

    2016-03-01

    Conversely to the continuous wave indirect time-of-flight (CW-iToF) imaging scheme, pulsed modulation ToF (PM-iToF) imaging is a promising depth measurement technique for operation at high ambient illumination. It is known that non-linearity and finite charge-transfer speed impact trueness and precision of ToF systems.1-3 As pulses are no Eigenfunctions to the shutter system, this issue is especially pronounced in pulsed modulation.2, 3 Despite these effects, it is possible to find analytical expressions founded on physical observations that map scenery parameters such as depth information, reflectance and ambient light level to sensor output.3, 4 In the application, the inverse of this map has to be evaluated. In PM-iToF, an inverse function cannot be yielded in a direct manner, as models proposed in the literature were transcendental.3, 4 For a limited range an approximating linearization can be performed to yield depth information.5 To extend the usable range, recently, an alternative approach that indirectly approximates the inverse function was presented.6 This method was founded on 1D doping concentration profiles, which, however, are typically not made available to end users. Also, limitations of the 1D approximation as well as stability are yet to be explored. This work presents a calibration methodology that copes with detector insufficiencies such as finite charge transfer speed. Contrarily to the state of the art, no prior knowledge on details of the underlying devices is required. The work covers measurement setup, a benchmark of various calibration schemes and deals with issues such as overfitting or defect pixels.

  16. Multivariate Modeling of Body Mass Index, Pulse Pressure, Systolic and Diastolic Blood Pressure in Chinese Twins

    DEFF Research Database (Denmark)

    Wu, Yili; Zhang, Dongfeng; Pang, Zengchang;

    2015-01-01

    Systolic and diastolic blood pressure, pulse pressure (PP), and body mass index (BMI) are heritable traits in human metabolic health but their common genetic and environmental backgrounds are not well investigated. The aim of this article was to explore the phenotypic and genetic associations among...... PP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. The studied sample contained 615 twin pairs (17-84 years) collected in the Qingdao municipality. Univariate and multivariate structural equation models were fitted for assessing the genetic and environmental contributions...... model estimated (1) high genetic correlations for DBP with SBP (0.87), PP with SBP (0.75); (2) low-moderate genetic correlations between PP and DBP (0.32), each BP component and BMI (0.24-0.37); (3) moderate unique environmental correlation for PP with SBP (0.68) and SBP with DBP (0.63); (4...

  17. Central Pulse Pressure in Chronic Kidney Disease: A CRIC Ancillary Study

    Science.gov (United States)

    Townsend, Raymond R.; Chirinos, Julio A.; Parsa, Afshin; Weir, Matthew A.; Sozio, Stephen M.; Lash, James P.; Chen, Jing; Steigerwalt, Susan P.; Go, Alan S.; Hsu, Chi-yuan; Rafey, Mohammed; Wright, Jackson T.; Duckworth, Mark J.; Gadegbeku, Crystal A.; Joffe, Marshall P.

    2010-01-01

    Central pulse pressure can be non-invasively derived using the radial artery tonometric methods. Knowledge of central pressure profiles has predicted cardiovascular morbidity and mortality in several populations of patients, particularly those with known coronary artery disease and those receiving dialysis. Few data exist characterizing central pressure profiles in patients with mild-moderate chronic kidney disease who are not on dialysis. We measured central pulse pressure cross-sectionally in 2531 participants in the Chronic Renal Insufficiency Cohort study to determine correlates of the magnitude of central pulse pressure in the setting of chronic kidney disease. Tertiles of central pulse pressure (CPP) were 51 mmHg with an overall mean (± S.D.) of 46 ± 19 mmHg. Multivariable regression identified the following independent correlates of central pulse pressure: age, gender, diabetes mellitus, heart rate (negatively correlated), glycosylated hemoglobin, hemoglobin, glucose and PTH concentrations. Additional adjustment for brachial mean arterial pressure and brachial pulse pressure showed associations for age, gender, diabetes, weight and heart rate. Discrete intervals of brachial pulse pressure stratification showed substantial overlap within the associated central pulse pressure values. The large size of this unique chronic kidney disease cohort provides an ideal situation to study the role of brachial and central pressure measurements in kidney disease progression and cardiovascular disease incidence. PMID:20660819

  18. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure (letter)

    NARCIS (Netherlands)

    Wain, L.V.; Verwoert, G.C.; O'Reilly, P.F.; Shi, G.; Johnson, T.; Johnson, A.D.; Bochud, M.; Rice, K.M.; Henneman, P.; Smith, A.V.; Ehret, G.B.; Amin, N.; Larson, M.G.; Mooser, V.; Hadley, D.; Dorr, M.; Bis, J.C.; Aspelund, T.; Esko, T.; Janssens, A.C.J.W.; Zhao, J.H.; Heath, S.; Laan, M.; Fu, J.Y.; Pistis, G.; Luan, J.A.; Arora, P.; Lucas, G.; Pirastu, N.; Pichler, I.; Jackson, A.U.; Webster, R.J.; Zhang, F.; Peden, J.F.; Schmidt, H.; Tanaka, T.; Campbell, H.; Igl, W.; Milaneschi, Y.; Hottenga, J.J.; Vitart, V.; Chasman, D.I.; Trompet, S.; Bragg-Gresham, J.L.; Alizadeh, B.Z.; Chambers, J.C.; Guo, X.Q.; Lehtimaki, T.; Kuhnel, B.; Lopez, L.M.; Polasek, O.; Boban, M.; Nelson, C.P.; Morrison, A.C.; Pihur, V.; Ganesh, S.K.; Hofman, A.; Kundu, S.; Mattace-Raso, F.U.S.; Rivadeneira, F.; Sijbrands, E.J.G.; Uitterlinden, A.G.; Hwang, S.J.; Vasan, R.S.; Wang, T.J.; Bergmann, S.; Vollenweider, P.; Waeber, G.; Laitinen, J.; Pouta, A.; Zitting, P.; McArdle, W.L.; Kroemer, H.K.; Volker, U.; Volzke, H.; Glazer, N.L.; Taylor, K.D.; Harris, T.B.; Alavere, H.; Haller, T.; Keis, A.; Tammesoo, M.L.; Aulchenko, Y.; Barroso, I.; Khaw, K.T.; Galan, P.; Hercberg, S.; Lathrop, M.; Eyheramendy, S.; Org, E.; Sober, S.; Lu, X.W.; Nolte, I.M.; Penninx, B.W.; Corre, T.; Masciullo, C.; Sala, C.; Groop, L.; Voight, B.F.; Melander, O.; O'Donnell, C.J.; Salomaa, V.; d'Adamo, A.P.; Fabretto, A.; Faletra, F.; Ulivi, S.; Del Greco, M.F.; Facheris, M.; Collins, F.S.; Bergman, R.N.; Beilby, J.P.; Hung, J.; Musk, A.W.; Mangino, M.; Shin, S.Y.; Soranzo, N.; Watkins, H.; Goel, A.; Hamsten, A.; Gider, P.; Loitfelder, M.; Zeginigg, M.; Hernandez, D.; Najjar, S.S.; Navarro, P.; Wild, S.H.; Corsi, A.M.; Singleton, A.; de Geus, E.J.C.; Willemsen, G.; Parker, A.N.; Rose, L.M.; Buckley, B.; Stott, D.; Orru, M.; Uda, M.; van der Klauw, M.M.; Zhang, W.H.; Li, X.Z.; Scott, J.; Chen, Y.D.I.; Burke, G.L.; Kahonen, M.; Viikari, J.; Doring, A.; Meitinger, T.; Davies, G.; Starr, J.M.; Emilsson, V.; Plump, A.; Lindeman, J.H.; 'T Hoen, P.A.C.; Konig, I.R.; Felix, J.F.; Clarke, R.; Hopewell, J.C.; Ongen, H.; Breteler, M.; Debette, S.; DeStefano, A.L.; Fornage, M.; Mitchell, G.F.; Smith, N.L.; Holm, H.; Stefansson, K.; Thorleifsson, G.; Thorsteinsdottir, U.; Samani, N.J.; Preuss, M.; Rudan, I.; Hayward, C.; Deary, I.J.; Wichmann, H.E.; Raitakari, O.T.; Palmas, W.; Kooner, J.S.; Stolk, R.P.; Jukema, J.W.; Wright, A.F.; Boomsma, D.I.; Bandinelli, S.; Gyllensten, U.B.; Wilson, J.F.; Ferrucci, L.; Schmidt, R.; Farrall, M.; Spector, T.D.; Palmer, L.J.; Tuomilehto, J.; Pfeufer, A.; Gasparini, P.; Siscovick, D.; Altshuler, D.; Loos, R.J.F.; Toniolo, D.; Snieder, H.; Gieger, C.; Meneton, P.; Wareham, N.J.; Oostra, B.A.; Metspalu, A.; Launer, L.; Rettig, R.; Strachan, D.P.; Beckmann, J.S.; Witteman, J.C.M.; Erdmann, J.; van Dijk, K.W.; Boerwinkle, E.; Boehnke, M.; Ridker, P.M.; Jarvelin, M.R.; Chakravarti, A.; Abecasis, G.R.; Gudnason, V.; Newton-Cheh, C.; Levy, D.; Munroe, P.B.; Psaty, B.M.; Caulfield, M.J.; Rao, D.C.; Tobin, M.D.; Elliott, P.; van Duijn, C.M.

    2011-01-01

    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans(1-3). We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we

  19. Calibrating airborne measurements of airspeed, pressure and temperature using a Doppler laser air-motion sensor

    Directory of Open Access Journals (Sweden)

    W. A. Cooper

    2014-09-01

    Full Text Available A new laser air-motion sensor measures the true airspeed with a standard uncertainty of less than 0.1 m s−1 and so reduces uncertainty in the measured component of the relative wind along the longitudinal axis of the aircraft to about the same level. The calculated pressure expected from that airspeed at the inlet of a pitot tube then provides a basis for calibrating the measurements of dynamic and static pressure, reducing standard uncertainty in those measurements to less than 0.3 hPa and the precision applicable to steady flight conditions to about 0.1 hPa. These improved measurements of pressure, combined with high-resolution measurements of geometric altitude from the global positioning system, then indicate (via integrations of the hydrostatic equation during climbs and descents that the offset and uncertainty in temperature measurement for one research aircraft are +0.3 ± 0.3 °C. For airspeed, pressure and temperature, these are significant reductions in uncertainty vs. those obtained from calibrations using standard techniques. Finally, it is shown that although the initial calibration of the measured static and dynamic pressures requires a measured temperature, once calibrated these measured pressures and the measurement of airspeed from the new laser air-motion sensor provide a measurement of temperature that does not depend on any other temperature sensor.

  20. An in vitro quantification of pressures exerted by earlobe pulse oximeter probes following reports of device-related pressure ulcers in ICU patients .

    Science.gov (United States)

    Goodell, Teresa T

    2012-11-01

    The earlobe often is used to monitor perfusion when pulse oximeter signal quality is impaired in the fingers and toes. Prompted by intermittent occurrences of roughly circular earlobe pressure ulcers among patients in intensive care units, a convenience sample of seven calibrated pulse oximeter probes was used to quantify earlobe pressure exerted by these devices in vitro. All were tested twice with an electronic load cell, a strain gauge with a transducer that transforms the measured force into a readable numerical signal. The probe was clipped to the load cell just as it is clipped to the earlobe in the clinical setting. The probes exerted an average of 0.24 lb (SD 0.6) of force over an area of 0.3 square inches, equal to an average of 20.7 mm Hg (SD 0.6) pressure on tissue. This value exceeds some empirically derived values of capillary perfusion pressure. The occurrence of device-related pressure ulcers, as well pressure ulcers on the ears, has been documented, but little is known about device-related earlobe pressure ulcers or the actual pressure exerted by these devices. Additional in vitro studies are needed to quantify the pressures exerted by these and other probes, and future prevalence and incidence studies should include more detailed pressure ulcer location and device use documentation. Until more is known about the possible role of these devices in the development of pressure ulcers, clinicians should be cognizant of their potential for causing pressure ulcers, particularly in patients whose conditions can compromise skin integrity.

  1. 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.

  2. Calibration of pulsed electroacoustic method considering electrode-dielectric interface status and porosity

    Science.gov (United States)

    Huang, Meng; Zhou, Yuanxiang; Chen, Weijiang; Lu, Licheng; Jin, Fubao; Huang, Jianwen

    2014-10-01

    Pulsed electroacoustic (PEA) method is widely used, but measurement conditions not always agree with the underlying PEA assumptions. This necessitates space charge recovery; however, existing research only addresses the attenuation and dispersion in lossy media. The effects of electrode-dielectric interface contact status and porosity on the accuracy of space charge distribution are discussed in the present article. It is shown that the presence of nonlinear interface and porosity can introduce severe error. However, because the properties of acoustic propagation of waves (which are generated from charge on the electrode and in the bulk) are different, the conventional recovery algorithm is no longer suitable for calibrating the charge density. To obtain accurate space charge profiles, it is necessary to eliminate these effects. A method has been proposed which is based on the original measurement process. The validity of the proposed method was tested by reasonable post-recovery electric field distributions.

  3. Self-Calibration and Laser Energy Monitor Validations for a Double-Pulsed 2-Micron CO2 Integrated Path Differential Absorption Lidar Application

    Science.gov (United States)

    Refaat, Tamer F.; Singh, Upendra N.; Petros, Mulugeta; Remus, Ruben; Yu, Jirong

    2015-01-01

    Double-pulsed 2-micron integrated path differential absorption (IPDA) lidar is well suited for atmospheric CO2 remote sensing. The IPDA lidar technique relies on wavelength differentiation between strong and weak absorbing features of the gas normalized to the transmitted energy. In the double-pulse case, each shot of the transmitter produces two successive laser pulses separated by a short interval. Calibration of the transmitted pulse energies is required for accurate CO2 measurement. Design and calibration of a 2-micron double-pulse laser energy monitor is presented. The design is based on an InGaAs pin quantum detector. A high-speed photo-electromagnetic quantum detector was used for laser-pulse profile verification. Both quantum detectors were calibrated using a reference pyroelectric thermal detector. Calibration included comparing the three detection technologies in the single-pulsed mode, then comparing the quantum detectors in the double-pulsed mode. In addition, a self-calibration feature of the 2-micron IPDA lidar is presented. This feature allows one to monitor the transmitted laser energy, through residual scattering, with a single detection channel. This reduces the CO2 measurement uncertainty. IPDA lidar ground validation for CO2 measurement is presented for both calibrated energy monitor and self-calibration options. The calibrated energy monitor resulted in a lower CO2 measurement bias, while self-calibration resulted in a better CO2 temporal profiling when compared to the in situ sensor.

  4. Energy calibration of CsI(Tl) scintillator in pulse-shape identification technique

    CERN Document Server

    Avdeichikov, V; Golubev, P; Jakobsson, B; Colonna, N

    2003-01-01

    A batch of 16 CsI(Tl) scintillator crystals, supplied by the Bicron Company, has been studied with respect to precise energy calibration in pulse-shape identification technique. The light corresponding to pulse integration within the time interval 1.6-4.5 mu s (long gate) and 0.0-4.5 mu s (extra-long gate) exhibits a power law relation, L(E,Z,A)=a1(Z,A)E sup a sup 2 sup ( sup Z sup , sup A sup ) , for sup 1 sup , sup 2 sup , sup 3 H isotopes in the measured energy range 5-150 MeV. For the time interval 0.0-0.60 mu s (short gate), a significant deviation from the power law relation is observed, for energy greater than approx 30 MeV. The character of the a2(p)-a2(d) and a2(p)-a2(t) correlations for protons, deuterons and tritons, reveals 3 types of crystals in the batch. These subbatches differ in the value of the extracted parameter a2 for protons, and in the value of the spread of a2 for deuterons and tritons. This may be explained by the difference in the energy dependence of the fast decay time component an...

  5. Design of low-power hybrid digital pulse width modulator with piecewise calibration scheme

    Science.gov (United States)

    Zhen, Shaowei; Hou, Sijian; Gan, Wubing; Chen, Jingbo; Luo, Ping; Zhang, Bo

    2015-12-01

    A low-power hybrid digital pulse width modulator (DPWM) is proposed in the paper. Owing to the piecewise calibration scheme, the delay time of delay line is locked to target frequency. The delay line consists of two piecewise lines with different control codes. The delay time of each cell in one sub-delay-line is longer than the last significant bit (LSB) of DPWM, while the delay time of each cell in the other sub-delay-line is shorter than LSB. Optimum linearity is realised with minimum standard cells. Simulation results show that the differential nonlinearity and integral nonlinearity are improved from 5.1 to 0.4 and from 5 to 1.3, respectively. The DPWM is fully synthesised and fabricated in a 90-nm CMOS process. The proposed DPWM occupies a silicon area of 0.01 mm2, with 31.5 μw core power consumption. Experimental results are shown to demonstrate the 2-MHz, 10-bit resolution implementation. Pulse width histogram is firstly introduced to characterise the linearity of the DPWM.

  6. The Relation Between Aortic Pulse Pressure and Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Ali Metin Esen

    2011-08-01

    Full Text Available Objective: Pulse pressure (PP is a significant marker of cardiovascular morbidity.We investigated the relation between aortic PP and the presence and extent of coronary artery disease (CAD in patients undergoing diagnostic coronary angiography (CAG.Patients and Method: The study group consisted of 550 patients (363 men, 187 women.We evaluated patients in two different groups, PP < 60 mmHg and ≥ 60 mmHg.Results: In univariate analysis gender and presence of hyperlipidemia showed no statistically significant differences between both groups. However, the ratio of patients having diabetes mellitus, hypertension or smoking were significantly higher in ≥ 60 mmHg PP group. The mean age was 55.2 ±11.9 in < 60 mmHg PP group and 61.3±9.3 in the other group (p<0.01. Although systolic blood pressure level was higher in ≥ 60 mmHg PP group (160.4±21.1 vs. 126.4±13.5, p< 0.001, diastolic blood pressure level showed no significant differences between both groups (78.3±13.5 vs. 80.3±10.2, p= 0.32. In the <60 mmHg PP group, the ratio of normal CAG was significantly higher, and also, the critically CAD rate was lower than the other group. In multivariate analysis, smoking [odds ratios (OR 2.344, 95% confidence intervals (CI, 1.416-3.879], male gender (OR 5.858, 95% CI, 3.425-10.019 and PP ≥60 mmHg (OR 25.788, 95% CI, 14.001-47.498 were evaluated as an independent indicators of CAD.Conclusions: In our study, we demonstrate that, aortic PP ≥60 mmHg is related to the risk of critically CAD as an independent factor.

  7. MP.EXE, a Calculation Program for Pressure Reciprocity Calibration of Microphones

    DEFF Research Database (Denmark)

    Rasmussen, Knud

    1998-01-01

    A computer program is described which calculates the pressure sensitivity of microphones based on measurements of the electrical transfer impedance in a reciprocity calibration set-up. The calculations are performed according to the International Standard IEC 6194-2. In addition a number of options...

  8. A CW calibrated laser pulse energy meter for the range 1 pJ to 100 mJ

    Science.gov (United States)

    White, M. G.; Leonhardt, R.; Livigni, D.; Lehman, J. H.

    2014-06-01

    We describe the use of a silicon photodiode trap detector and digital storage oscilloscope as an absolute laser pulse energy meter, capable of repetition rates of 85 Hz and 5% uncertainty (k = 2). The maximum repetition rate is limited by the decay time of the output pulse of the detector. The technique relies on a straightforward oscilloscope-based integration of the voltage pulse generated by the photodiode trap detector. We highlight the versatility of the technique by comparing it at 1064 nm with our high and low-level calorimeter based pulse energy scales, to which our calibration services are traceable. The good agreement of the results, along with comprehensive uncertainty analysis, validates the approach we have taken. We have demonstrated a basis for establishing laser pulse energy measurement using continuous wave (CW) sources and standard detectors.

  9. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    Science.gov (United States)

    Wain, Louise V; Verwoert, Germaine C; O’Reilly, Paul F; Shi, Gang; Johnson, Toby; Johnson, Andrew D; Bochud, Murielle; Rice, Kenneth M; Henneman, Peter; Smith, Albert V; Ehret, Georg B; Amin, Najaf; Larson, Martin G; Mooser, Vincent; Hadley, David; Dörr, Marcus; Bis, Joshua C; Aspelund, Thor; Esko, Tõnu; Janssens, A Cecile JW; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian’an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U; Webster, Rebecca J; Zhang, Feng; Peden, John F; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hotteng, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I; Trompet, Stella; Bragg-Gresham, Jennifer L; Alizadeh, Behrooz Z; Chambers, John C; Guo, Xiuqing; Lehtimäki, Terho; Kühnel, Brigitte; Lopez, Lorna M; Polašek, Ozren; Boban, Mladen; Nelson, Christopher P; Morrison, Alanna C; Pihur, Vasyl; Ganesh, Santhi K; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco US; Rivadeneira, Fernando; Sijbrands, Eric JG; Uitterlinden, Andre G; Hwang, Shih-Jen; Vasan, Ramachandran S; Wang, Thomas J; Bergmann, Sven; Vollenweider, Peter; Waeber, Gérard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Glazer, Nicole L; Taylor, Kent D; Harris, Tamara B; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Inês; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sõber, Siim; Lu, Xiaowen; Nolte, Ilja M; Penninx, Brenda W; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F; Melander, Olle; O’Donnell, Christopher J; Salomaa, Veikko; d’Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, M Fabiola; Facheris, Maurizio; Collins, Francis S; Bergman, Richard N; Beilby, John P; Hung, Joseph; Musk, A William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S; Navarro, Pau; Wild, Sarah H; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco JC; Willemsen, Gonneke; Parker, Alex N; Rose, Lynda M; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L; Kähönen, Mika; Viikari, Jorma; Döring, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H; ’t Hoen, Peter AC; König, Inke R; Felix, Janine F; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Breteler, Monique; Debette, Stéphanie; DeStefano, Anita L; Fornage, Myriam; Mitchell, Gary F; Smith, Nicholas L; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J; Wichmann, H-Erich; Raitakari, Olli T; Palmas, Walter; Kooner, Jaspal S; Stolk, Ronald P; Jukema, J Wouter; Wright, Alan F; Boomsma, Dorret I; Bandinelli, Stefania; Gyllensten, Ulf B; Wilson, James F; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D; Palmer, Lyle J; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth JF; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J; Oostra, Ben A; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P; Beckmann, Jacques S; Witteman, Jacqueline CM; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B; Psaty, Bruce M; Caulfield, Mark J; Rao, Dabeeru C

    2012-01-01

    Numerous genetic loci influence systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans 1-3. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N=74,064) and follow-up studies (N=48,607), we identified at genome-wide significance (P= 2.7×10-8 to P=2.3×10-13) four novel PP loci (at 4q12 near CHIC2/PDGFRAI, 7q22.3 near PIK3CG, 8q24.12 in NOV, 11q24.3 near ADAMTS-8), two novel MAP loci (3p21.31 in MAP4, 10q25.3 near ADRB1) and one locus associated with both traits (2q24.3 near FIGN) which has recently been associated with SBP in east Asians. For three of the novel PP signals, the estimated effect for SBP was opposite to that for DBP, in contrast to the majority of common SBP- and DBP-associated variants which show concordant effects on both traits. These findings indicate novel genetic mechanisms underlying blood pressure variation, including pathways that may differentially influence SBP and DBP. PMID:21909110

  10. Characteristics of wind pressure pulse on large-span flat roofs

    Institute of Scientific and Technical Information of China (English)

    SUN Ying; CAO Zheng-gang; WU Yue

    2009-01-01

    The wind pressure pulse events, among the most important characteristics of wind pressure fluctuations on large-span fiat roofs, were investigated by wind tunnel tests in this paper. Incorporating the formation mechanism of wind pressure pulse events, the peak over threshold method was employed to study properties of this kind of events. The event duration time, the energy contribution, the number of the pulse events, and the distribution of average peak pressure were calculated. Probability density functions of some typical samples in separation region were also given. Results show that the non-Gaussian roof pressure is strong in the flow separa tion region owing to the wind pressure pulse events. Evaluations of the extreme peak pressures, which can be determined by the peak over threshold method effectively, are important to the design of building cladding.

  11. Investigation of Nanosecond Pulsed Discharge and Its Audio Characteristics in Atmospheric-pressure Air

    Institute of Scientific and Technical Information of China (English)

    REN Chengyan; RAN Huijuan; WANG Jue; WANG Tao; YAN Ping

    2013-01-01

    There was no well-resolved mechanism of audible noise caused by corona discharge on UHV transmission lines.Hence we measured the sound pressure of pulsed discharges between needle-plane electrodes under different discharge conditions in air,for revealing the intrinsic relationship between discharge and its audible noise(AN).The relationship between discharge parameters and audio characteristics was drawn from the analysis of the electric and sound signals obtained in experiments.Experiment results showed that nanosecond pulsed discharges produce the sound pressure with a microsecond pulse lagging behind the discharge pulse in their waveforms.The peak value of the sound pulse decreases and its high frequency component gradually attenuates,when the measuring distance from discharges increases.The sound pulses correlate with the discharge current and voltage significantly,especially the current.The audible noise produced by repetitive pulsed discharge increases with the strength,duration,and pulse repetition rate of discharge.

  12. In situ pressure calibration for piston cylinder cells via ruby fluorescence with fiber optics.

    Science.gov (United States)

    Koyama-Nakazawa, Kazuko; Koeda, Masahito; Hedo, Masato; Uwatoko, Yoshiya

    2007-06-01

    A fiber-optic measurement technique is developed for estimating the pressure inside a piston cylinder cell up to approximately 4 GPa, based on the pressure-induced R1 fluorescence line shift of ruby (ruby scale). Ruby scale and a conventional technique (calibration on phase transitions of bismuth) were simultaneously applied to the cell filled with a pressure transmitting medium of isopropyl alcohol. The pressure readings of the two methods were consistent with each other, and no pressure gradient was observed. The ruby scale has the advantages of real time estimation and easy installation in a small space. Because of these advantages, three fibers were simultaneously introduced in the sample space at the same time, and pressure distribution was measured for Fluorinert (FC70:FC77=1:1), Daphne oil 7373, and Fomblin oil (YHVAC 13014).

  13. Sarcopenia Is Associated with High Pulse Pressure in Older Women

    Directory of Open Access Journals (Sweden)

    Hélio José Coelho Júnior

    2015-01-01

    Full Text Available Introduction. Sarcopenia is a geriatric syndrome associated with impairment of muscle function, metabolism, and cognition in older women. Recent studies have shown a relationship between changes in muscle mass and the cardiovascular system. However, this relationship has not been fully elucidated. Methods. One hundred and thirty community-dwelling Brazilian older women (65.4 ± 6.3 years were recruited to participate in this study. Data on body composition (via bioelectrical impedance measurements, cardiovascular parameters (using an automatic and noninvasive monitor, and muscle function (using a 3-meter gait speed test were measured. Results. Sarcopenic older women (n=43 presented higher levels of pulse pressure (PP (60.3 ± 2.6 mmHg and lower muscle function (0.5 ± 0.0 m/s compared with nonsarcopenic subjects (n=87 (53.7 ± 1.5 mmHg; 0.9 ± 0.0 m/s (P<0.05. Linear regression analysis demonstrated a significantly negative association between skeletal muscle index (SMI and PP levels (β=−226, P<0.05. Furthermore, sarcopenic older women showed a 3.1-fold increased risk of having higher PP levels compared with nonsarcopenic women (IC = 1.323–7.506 (P<0.05. Conclusion. Sarcopenic older women showed lower muscle function and higher cardiovascular risk due to increased PP levels compared with nonsarcopenic subjects.

  14. Pasteurization of fruit juices by means of a pulsed high pressure process.

    Science.gov (United States)

    Donsì, Giorgio; Ferrari, Giovanna; Maresca, Paola

    2010-04-01

    The use of pulsed high hydrostatic pressure was investigated as a possible approach to stabilize foodstuffs. The objective of this article was to investigate the effect of the main processing variables (pressure [150 to 300 MPa], temperature levels [25 to 50 degrees C], and pulse number [1 to 10]) on the sanitation of nonpasteurized clear Annurca apple juice as well as freshly-squeezed clear orange juice. The aim of the article was the optimization of the process parameters in step-wise pressure treatment (pressure holding time of each pulse: 60 s, compression rate: 10.5 MPa/s, decompression time: 2 to 5s). The shelf life of the samples, processed at optimized conditions, was evaluated in terms of microbiological stability and quality retention. According to our experimental results, the efficiency of pulsed high pressure processes depends on the combination of pulse holding time and number of pulses. The pulsed high pressure cycles have no additive or synergetic effect on microbial count. The efficacy of the single pulses decreases with the increase of the pulse number and pressure level. Therefore the first pulse cycle is more effective than the following ones. By coupling moderate heating to high pressure, the lethality of the process increases but thermal degradation of the products can be detected. The optimization of the process condition thus results in a compromise between the reduction of the pressure value, due to the synergetic temperature action, and the achievement of quality of the final production. The juices processed under optimal processing conditions show a minimum shelf life of 21 d at a storage temperature of 4 degrees C.

  15. Characteristics of SF6 Switch with a Small Gap under High Pressure and Nanosecond Pulse

    Institute of Scientific and Technical Information of China (English)

    TANG Junping; QIU Aici; BO Haiwang; DONG Qinxiao; HE Xiaoping

    2009-01-01

    Structural design and tests on the characteristics of the SFs gas switch with a small gap are presented. This kind of switch often works under high pressure and nanosecond pulse for getting pulse with faster risetime. The breakdown voltage and breakdown delay of a number of switches with different geometries, gas pressures and pulse waveforms were investigated.Experimental results suggested that the breakdown voltage increases linearly with the gas pressure,and the breakdown delay decreases with an increase in the gas pressure and a reduction in the gap distance of the switch under the same applied pulse. By using this kind of switch with a gap of 3 mm as a peaking switch, a pulse generator can provide an output voltage with a peak voltage of 300 kV and a risetime of 3 ns on a resistance load of 150 Ω.

  16. The Narrow Pulse Calibration System Based on Hopkinson Bar%基于Hopkinson杆的窄脉冲校准系统∗

    Institute of Scientific and Technical Information of China (English)

    李玺; 范锦彪; 王燕; 徐鹏

    2015-01-01

    针对目前动态校准装置难以安全产生窄脉冲激励信号的问题,基于Hopkinson压杆技术,以压缩空气作为激励源,采用子弹撞击杆的方式,提出了一种可以产生6~10μs窄脉冲校准系统。该系统选用600 mm ×10 mm的钛合金Hopkinson杆,使用应变片和轴向激光干涉仪同时测量获取窄脉冲信号。利用该系统进行了动态校准实验,实验结果表明,该系统产生的窄脉冲可充分激励起8309的谐振频率,通过幅频特性曲线得其工作频带。%present dynamic calibration deviceproduce narrow pulse excitation signal, based on Hopkinson pressure bar technique, com-pressed air as a source of motivationthe way of bullet, a kind of calibration system that can produce 6~10 μs narrow pulse. The system 600 mm × 10 mm titanium alloy Hopkinson bar, strain gauge and axial laser interferometer measurement for narrow pulse signal at the same time. his system dynamic calibration experiment, the experimental results show that the system can fully motivate resonance frequency of the acceleration sensor 8309, its working frequency band obtained through the amplitude-frequency characteristic curve.

  17. Dynamic effects of high-pressure pulsed water jet in low-permeability coal seams

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-hong; ZHOU Dong-ping; LU Yi-yu; KANG Yong; ZHAO Yu; WANG Xiao-chuan

    2009-01-01

    Mine gas extraction in China is difficult due to the characteristics such as mi-cro-porosity, low-permeability and high adsorption of coal seams. The pulsed mechanism of a high-pressure pulsed water jet was studied through theoretical analysis, experiment and field measurement. The results show that high-pressure pulsed water jet has three dynamic properties. What's more, the three dynamic effects can be found in low-perme-ability coal seams. A new pulsed water jet with 200-1 000 Hz oscillation frequency and peak pressure 2.5 times than average pressure was introduced. During bubble collapsing, sound vibration and instantaneous high pressures over 100 MPa enhanced the cutting ability of the high-pressure jet. Through high-pressure pulsed water jet drilling and slotting, the exposure area of coal bodies was greatly enlarged and pressure of the coal seams rapidly decreased. Therefore, the permeability of coal seams was improved and gas ab-sorption rate also decreased. Application results show that gas adsorption rate decreased by 30%-40% and the penetrability coefficient increased 100 times. This proves that high-pressure pulsed water is more efficient than other conventional methods.

  18. Multivariate regression and discreminant calibration models for a novel optical non-invasive blood glucose measurement method named pulse glucometry.

    Science.gov (United States)

    Yamakoshi, Yasuhiro; Ogawa, Mitsuhiro; Yamakoshi, Takehiro; Tamura, Toshiyo; Yamakoshi, Ken-ichi

    2009-01-01

    A novel optical non-invasive in vivo blood glucose concentration (BGL) measurement technique, named "Pulse Glucometry", was combined with a kernel method; support vector machines. The total transmitted radiation intensity (I(lambda)) and the cardiac-related pulsatile changes superimposed on I(lambda) in human adult fingertips were measured over the wavelength range from 900 to 1700 nm using a very fast spectrophotometer, obtaining a differential optical density (DeltaOD(lambda)) related to the blood component in the finger tissues. Subsequently, a calibration model using paired data of a family of DeltaOD(lambda)s and the corresponding known BGLs was constructed with support vector machines (SVMs) regression instead of using calibration by a conventional primary component regression (PCR) and partial least squares regression (PLS). Secondly, SVM method was applied to make a nonlinear discriminant calibration model for "Pulse glucometry." Our results show that the regression calibration model based on the support vector machines can provide a good regression for the 101 paired data, in which the BGLs ranged from 89.0-219 mg/dl (4.94-12.2 mmol/l). The resultant regression was evaluated by the Clarke error grid analysis and all data points fell within the clinically acceptable regions (region A: 93%, region B: 7%). The discriminant calibration model using SVMs also provided a good result for classification (accuracy rate 84% in the best case).

  19. Estimation of fracture flow parameters through numerical analysis of hydromechanical pressure pulses

    Energy Technology Data Exchange (ETDEWEB)

    Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C.-F.; Thoraval, A.

    2008-03-16

    The flow parameters of a natural fracture were estimated by modeling in situ pressure pulses. The pulses were generated in two horizontal boreholes spaced 1 m apart vertically and intersecting a near-vertical highly permeable fracture located within a shallow fractured carbonate reservoir. Fracture hydromechanical response was monitored using specialized fiber-optic borehole equipment that could simultaneously measure fluid pressure and fracture displacements. Measurements indicated a significant time lag between the pressure peak at the injection point and the one at the second measuring point, located 1 m away. The pressure pulse dilated and contracted the fracture. Field data were analyzed through hydraulic and coupled hydromechanical simulations using different governing flow laws. In matching the time lag between the pressure peaks at the two measuring points, our hydraulic models indicated that (1) flow was channeled in the fracture, (2) the hydraulic conductivity tensor was highly anisotropic, and (3) the radius of pulse influence was asymmetric, in that the pulse travelled faster vertically than horizontally. Moreover, our parametric study demonstrated that the fluid pressure diffusion through the fracture was quite sensitive to the spacing and orientation of channels, hydraulic aperture, storativity and hydraulic conductivity. Comparison between hydraulic and hydromechanical models showed that the deformation significantly affected fracture permeability and storativity, and consequently, the fluid pressure propagation, suggesting that the simultaneous measurements of pressure and mechanical displacement signals could substantially improve the interpretation of pulse tests during reservoir characterization.

  20. A time-delay calibrated method for cornea hysteresis and intraocular pressure measurement

    Science.gov (United States)

    Wang, Kuo-Jen; Tsai, Che-Liang; Wang, Wai; Hsu, Long; Hsu, Ken-Yuh

    2016-04-01

    The presence of cornea hysteresis (CH) in characterizing the intraocular pressure (IOP) of a human eye deteriorates the accuracy of IOP. To suppress CH, the pressure gauge of a tonometer must be located as close as possible to the cornea. However, this arrangement is unpractical because appropriate working distance to the cornea is required. In this paper, a time-delay calibrated (TDC) method is proposed to counteract the undesired effect of CH in characterizing the IOP. Employing this TDC method, the CH approaches to zero for most eyes measured.

  1. A note on the calibration of pressure-velocity sound intensity probes

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Jaud, Virginie

    2006-01-01

    from a small hole in a plane baffle, a near field method where the sound is emitted from a hole in a spherical baffle, and a method that involves an impedance tube. The performance of the two near field methods is examined both in an anechoic room and in various ordinary rooms. It is shown that whereas......A pressure-velocity sound intensity probe is a device that combines a pressure microphone with a particle velocity transducer. Various methods of calibrating such sound intensity probes are examined: a far field method that requires an anechoic room, a near field method that involves sound emitted...

  2. Shock-tube calibration of a fast-response pressure transducer

    Science.gov (United States)

    Chung, Kung-Ming; Lu, Frank K.

    1990-01-01

    The sensitivity of a miniature fast-response piezoresistive pressure transducer determined dynamically was found to be slightly higher than that determined statically. Thus, mean pressures in a turbulent or unsteady flowfield that are measured using statically-calibrated pressure transducers would be slightly above true values. Unsteady pressure measurements to obtain space-time correlations and spectra can, however, be properly performed if the slight error is acceptable. These measurements are, obviously, subjected to limitations imposed by the bandwidth and the spatial resolution of the transducer. The noise spectrum revealed that the noise is predominantly above the transducer's resonant frequency. Filtering to improve the signal-to-noise ratio is particularly necessary when using the transducers at their low range. Transducer drift increases the signal-to-noise ratio and can adversely affect mean measurements.

  3. Cerebrospinal fluid pulse pressure amplitude during lumbar infusion in idiopathic normal pressure hydrocephalus can predict response to shunting

    Directory of Open Access Journals (Sweden)

    Brean Are

    2010-02-01

    Full Text Available Abstract Background We have previously seen that idiopathic normal pressure hydrocephalus (iNPH patients having elevated intracranial pressure (ICP pulse amplitude consistently respond to shunt surgery. In this study we explored how the cerebrospinal fluid pressure (CSFP pulse amplitude determined during lumbar infusion testing, correlates with ICP pulse amplitude determined during over-night ICP monitoring and with response to shunt surgery. Our goal was to establish a more reliable screening procedure for selecting iNPH patients for shunt surgery using lumbar intrathecal infusion. Methods The study population consisted of all iNPH patients undergoing both diagnostic lumbar infusion testing and continuous over-night ICP monitoring during the period 2002-2007. The severity of iNPH was assessed using our NPH grading scale before surgery and 12 months after shunting. The CSFP pulse was characterized from the amplitude of single pressure waves. Results Totally 62 iNPH patients were included, 45 of them underwent shunt surgery, in whom 78% were shunt responders. Among the 45 shunted patients, resistance to CSF outflow (Rout was elevated (≥ 12 mmHg/ml/min in 44. The ICP pulse amplitude recorded over-night was elevated (i.e. mean ICP wave amplitude ≥ 4 mmHg in 68% of patients; 92% of these were shunt responders. In those with elevated overnight ICP pulse amplitude, we found also elevated CSFP pulse amplitude recorded during lumbar infusion testing, both during the opening phase following lumbar puncture and during a standardized period of lumbar infusion (15 ml Ringer over 10 min. The clinical response to shunting after 1 year strongly associated with the over-night ICP pulse amplitude, and also with the pulsatile CSFP during the period of lumbar infusion. Elevated CSFP pulse amplitude during lumbar infusion thus predicted shunt response with sensitivity of 88 and specificity of 60 (positive and negative predictive values of 89 and 60

  4. Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

    Science.gov (United States)

    Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

    2015-01-01

    Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at highpressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NOx emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8%.

  5. Determination of instantaneous pressure in a transonic base flow using four-pulse tomographic PIV

    NARCIS (Netherlands)

    Blinde, P.L.; Lynch, K.P.; Schrijer, F.F.J.; Van Oudheusden, B.W.

    2015-01-01

    A tomographic four-pulse PIV system is used in a transonic axisymmetric base flow experiment at a nominal free stream Mach number of 0.7, with the objective to obtain flow acceleration and pressure data. The PIV system, consisting of two double-pulse lasers and twelve cameras, allows acquiring two v

  6. Reflectance pulse oximetry at the forehead of newborns : The influence of varying pressure on the probe

    NARCIS (Netherlands)

    Dassel, ACM; Graaff, R; Zijlstra, WG; Aarnoudse, JG

    1996-01-01

    Objective: Transmission pulse oximetry (TPO) is not a practical method of intrapartum fetal monitoring of arterial oxygen saturation. Reflectance pulse oximetry (RPO) requires a sensor applied to the skin of the fetal head and may be a useful technique. During labor, various degrees of pressure will

  7. Use of pulsed-high hydrostatic pressure treatment to decrease patulin in apple juice

    Science.gov (United States)

    Avsaroglu, M. D.; Bozoglu, F.; Alpas, H.; Largeteau, A.; Demazeau, G.

    2015-04-01

    This study was aimed at reducing patulin content of apple juice using a non-thermal method, namely pulsed-high hydrostatic pressure (p-HHP). Commercially available clear apple juice was contaminated artificially with different concentrations of patulin (5, 50 and 100 ppb). Then, the samples were processed 5 min at different pressure treatments (300-500 MPa) in combination with different temperatures (30-50°C) and pulses (6 pulses × 50 s and 2 pulses × 150 s). To compare the impact of pulses, single pulse of high hydrostatic pressure (HHP) treatment was also applied with the same pressure/temperature combinations and holding time. Results indicated that pressure treatment in combination with mild heat and pulses reduced the levels of patulin in clear apple juice up to 62.11%. However, reduction rates did not follow a regular pattern. p-HHP was found to be more effective in low patulin concentrations, whereas HHP was more effective for high patulin concentrations. To the best of our knowledge, this is the first study using p-HHP to investigate the reduction of patulin content in apple juice.

  8. Global Remote Sensing of Precipitating Electron Energies: A Comparison of Substorms and Pressure Pulse Related Intensifications

    Science.gov (United States)

    Chua, D.; Parks, G. K.; Brittnacher, M. J.; Germany, G. A.; Spann, J. F.

    2000-01-01

    The Polar Ultraviolet Imager (UVI) observes aurora responses to incident solar wind pressure pulses and interplanetary shocks such its those associated with coronal mass ejections. Previous observations have demonstrated that the arrival of it pressure pulse at the front of the magnetosphere results in highly disturbed geomagnetic conditions and a substantial increase in both dayside and nightside aurora precipitations. Our observations show it simultaneous brightening over bread areas of the dayside and nightside auroral in response to a pressure pulse, indicating that more magnetospheric regions participate as sources for auroral precipitation than during isolate substorm. We estimate the characteristic energies of incident auroral electrons using Polar UVI images and compare the precipitation energies during pressure pulse associated event to those during isolated substorms. We estimate the characteristic energies of incident auroral electrons using Polar UVI images and compare the precipitation energies during pressure pulse associated events to those during isolated auroral substorms. Electron precipitation during substorms has characteristic energies greater than 10 KeV and is structured both in local time and in magnetic latitude. For auroral intensifications following the arrival of'a pressure pulse or interplanetary shock. Electron precipitation is less spatially structured and has greater flux of lower characteristic energy electrons (Echar less than 7 KeV) than during isolated substorm onsets. These observations quantify the differences between global and local auroral precipitation processes and will provide a valuable experimental check for models of sudden storm commencements and magnetospheric response to perturbations in the solar wind.

  9. Elevated pulse pressure is associated with hemolysis, proteinuria and chronic kidney disease in sickle cell disease.

    Directory of Open Access Journals (Sweden)

    Enrico M Novelli

    Full Text Available A seeming paradox of sickle cell disease is that patients do not suffer from a high prevalence of systemic hypertension in spite of endothelial dysfunction, chronic inflammation and vasculopathy. However, some patients do develop systolic hypertension and increased pulse pressure, an increasingly recognized major cardiovascular risk factor in other populations. Hence, we hypothesized that pulse pressure, unlike other blood pressure parameters, is independently associated with markers of hemolytic anemia and cardiovascular risk in sickle cell disease. We analyzed the correlates of pulse pressure in patients (n  =  661 enrolled in a multicenter international sickle cell trial. Markers of hemolysis were analyzed as independent variables and as a previously validated hemolytic index that includes multiple variables. We found that pulse pressure, not systolic, diastolic or mean arterial pressure, independently correlated with high reticulocyte count (beta  =  2.37, p  =  0.02 and high hemolytic index (beta  =  1.53, p = 0.002 in patients with homozygous sickle cell disease in two multiple linear regression models which include the markers of hemolysis as independent variables or the hemolytic index, respectively. Pulse pressure was also independently associated with elevated serum creatinine (beta  =  3.21, p  =  0.02, and with proteinuria (beta  =  2.52, p  =  0.04. These results from the largest sickle cell disease cohort to date since the Cooperative Study of Sickle Cell Disease show that pulse pressure is independently associated with hemolysis, proteinuria and chronic kidney disease. We propose that high pulse pressure may be a risk factor for clinical complications of vascular dysfunction in sickle cell disease. Longitudinal and mechanistic studies should be conducted to confirm these hypotheses.

  10. A novel biphasic-current-pulse calibration technique for electrical neural stimulation.

    Science.gov (United States)

    Maohua Ren; Jinyong Zhang; Lei Wang; Zhenyu Wang

    2014-01-01

    One of the major challenge in neural prosthetic device design is to ensure charge-balanced stimulation. This paper presents a new calibration technique to minimize the mismatch between anodic and cathodic current amplitudes. The proposed circuit mainly consists of a digital and an analog calibration, where a successive approximation register (SAR) logic and a comparator are used in digital calibration while a source follower is adopted in analog calibration. With a 0.18 μm high voltage CMOS process, the simulation shows that the maximum current mismatch is 45 nA (<0.05%).

  11. Integrated experimental test program on waterhammer pressure pulses and associated structural responses within a feedwater sparger

    Energy Technology Data Exchange (ETDEWEB)

    Nurkkala, P.; Hoikkanen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the steam generator. The feedwater sparger was subjected to the full range of operating parameters which were to result in waterhammer pressure pulse trains of various magnitudes and duration. Two different designs of revised feedwater sparger were investigated (i.e. `grounded` and `with goose neck`). The following objects were to be met within this program: (1) establish the thermohydraulic parameters that facilitate the occurrence of water hammer pressure pulses, (2) provide a database for further analysis of the pressure pulse phenomena, (3) establish location and severity of these water hammer pressure pulses, (4) establish the structural response due to these pressure pulses, (5) provide input data for structural integrity analysis. (orig.). 3 refs.

  12. Novel method for estimating the dynamic characteristics of pressure sensor in shock tube calibration test.

    Science.gov (United States)

    Li, Qiang; Wang, Zhongyu; Wang, Zhuoran; Yan, Hu

    2015-06-01

    A shock tube is usually used to excite the dynamic characteristics of the pressure sensor used in an aircraft. This paper proposes a novel estimation method for determining the dynamic characteristic parameters of the pressure sensor. A preprocessing operation based on Grey Model [GM(1,1)] and bootstrap method (BM) is employed to analyze the output of a calibrated pressure sensor under step excitation. Three sequences, which include the estimated value sequence, upper boundary, and lower boundary, are obtained. The processing methods on filtering and modeling are used to explore the three sequences independently. The optimal estimated, upper boundary, and lower boundary models are then established. The three models are solved, and a group of dynamic characteristic parameters corresponding to the estimated intervals are obtained. A shock tube calibration test consisting of two experiments is performed to validate the performance of the proposed method. The results show that the relative errors of the dynamic characteristic parameters of time and frequency domains do not exceed 9% and 10%, respectively. Moreover, the nominal and estimated values of the parameters fall into the estimated intervals limited by the upper and lower values.

  13. Pressure tunable cascaded third order nonlinearity and temporal pulse switching

    DEFF Research Database (Denmark)

    Eilenberger, Falk; Bache, Morten; Minardi, Stefano

    2013-01-01

    Effects based on the χ(3)-nonlinearity are arguably the most commonly discussed nonlinear interactions in photonics. In the description of pulse propagation, however, the generation of the third harmonic (TH) is commonly neglected, because it is strongly phase mismatched in most materials and wav...

  14. Flow Reactor Studies with Nanosecond Pulsed Discharges at Atmospheric Pressure and Higher

    Science.gov (United States)

    2013-10-01

    Image of Discharge Reactor with Viewport Inlet Cap • Modular plasma discharge reactor can be interchanged with redesigned pressure shell to perform...Flow Reactor Studies with Nanosecond Pulsed Discharges at Atmospheric Pressure and Higher Nicholas Tsolas, Kuni Togai and Richard Yetter...Department of Mechanical and Nuclear Engineering The Pennsylvania State University University Park, PA, 16801 Fourth Annual Review Meeting of the

  15. A viscoelastic spring-block model for investigating subglacial water pressure pulse generation

    Science.gov (United States)

    Kavanaugh, J. L.

    2009-12-01

    A viscoelastic spring-block model of glacier motion has been developed to investigate the mechanisms responsible for generating brief pulses in subglacial water pressure recorded at Trapridge Glacier, Yukon. In this model, the glacier is treated as an array of ice blocks, each of which is connected to its nearest neighbors by spring-and-dashpot linkages. The model glacier is gravitationally driven, and down-slope flow is resisted by a basal shear stress determined by the Mohr-Coulomb failure criterion. This model is forced with realistic basal water pressure conditions. With prescribed summer-mode, diurnally-varying pressures, the model produces elevated slip activity at times of rising (rather than peak) water pressures; with steady, elevated winter-mode pressures, slip events occur at non-uniform intervals due to the effects of elastic loading and the (nonlinear) viscous relaxation of stresses. Magnitude and interevent time statistics for model slip events and basal water pressure pulses are compared.

  16. Acute changes in pulse pressure in relation to constituents of particulate air pollution in elderly persons

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Lotte [Occupational and Environmental Medicine, Unit of Lung Toxicology, K.U.Leuven, Leuven (Belgium); Buczynska, Anna [Departement of Chemistry, UA, Wilrijk (Belgium); Walgraeve, Christophe [Research group EnVOC, Department of Sustainable Organic Chemistry and Technology, UGent, Gent (Belgium); Delcloo, Andy [Royal Meteorological Institute, Brussels (Belgium); Potgieter-Vermaak, Sanja [Departement of Chemistry, UA, Wilrijk (Belgium); Molecular Science Institute, School of Chemistry, University of Witwatersrand, Johannesburg (South Africa); Division of Chemistry and Environmental Science, Manchester Metropolitan University, Manchester (United Kingdom); Van Grieken, Rene [Departement of Chemistry, UA, Wilrijk (Belgium); Demeestere, Kristof; Dewulf, Jo; Van Langenhove, Herman [Research group EnVOC, Department of Sustainable Organic Chemistry and Technology, UGent, Gent (Belgium); De Backer, Hugo [Royal Meteorological Institute, Brussels (Belgium); Nemery, Benoit, E-mail: ben.nemery@med.kuleuven.be [Occupational and Environmental Medicine, Unit of Lung Toxicology, K.U.Leuven, Leuven (Belgium); Nawrot, Tim S. [Occupational and Environmental Medicine, Unit of Lung Toxicology, K.U.Leuven, Leuven (Belgium); Centre for Environmental Sciences, Hasselt University, Diepenbeek (Belgium)

    2012-08-15

    An increased pulse pressure (difference between systolic and diastolic blood pressure) suggests aortic stiffening. The objective of this study was to examine the acute effects of both particulate matter (PM) mass and composition on blood pressure, among elderly persons. We carried out a panel study in persons living in elderly homes in Antwerp, Belgium. We recruited 88 non-smoking persons, 70% women with a mean age of 83 years (standard deviation: 5.2). Blood pressure was measured and a blood sample was collected on two time points, which were chosen so that there was an exposure contrast in ambient PM exposure. The elemental content of the collected indoor and outdoor PM{sub 2.5} (particulate matter with an aerodynamic diameter <2.5 {mu}m) mass concentration was measured. Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) on outdoor PM{sub 10} (particulate matter with an aerodynamic diameter <10 {mu}m) were measured. Each interquartile range increase of 20.8 {mu}g/m Superscript-Three in 24-h mean outdoor PM{sub 2.5} was associated with an increase in pulse pressure of 4.0 mmHg (95% confidence interval: 1.8-6.2), in persons taking antihypertensive medication (n=57), but not in persons not using antihypertensive medication (n=31) (p for interaction: 0.02). Vanadium, iron and nickel contents of PM{sub 2.5} were significantly associated with systolic blood pressure and pulse pressure, among persons on antihypertensive medication. Similar results were found for indoor concentrations. Of the oxy-PAHs, chrysene-5,6-dione and benzo[a]pyrene-3,6-dione were significantly associated with increases in systolic blood pressure and pulse pressure. In elderly, pulse pressure was positively associated with acute increases in outdoor and indoor air pollution, among persons taking antihypertensive medication. These results might form a mechanistic pathway linking air pollution as a trigger of cardiovascular events.

  17. Tree shoot bending generates hydraulic pressure pulses: a new long-distance signal?

    Science.gov (United States)

    Lopez, Rosana; Badel, Eric; Peraudeau, Sebastien; Leblanc-Fournier, Nathalie; Beaujard, François; Julien, Jean-Louis; Cochard, Hervé; Moulia, Bruno

    2014-05-01

    When tree stems are mechanically stimulated, a rapid long-distance signal is induced that slows down primary growth. An investigation was carried out to determine whether the signal might be borne by a mechanically induced pressure pulse in the xylem. Coupling xylem flow meters and pressure sensors with a mechanical testing device, the hydraulic effects of mechanical deformation of tree stem and branches were measured. Organs of several tree species were studied, including gymnosperms and angiosperms with different wood densities and anatomies. Bending had a negligible effect on xylem conductivity, even when deformations were sustained or were larger than would be encountered in nature. It was found that bending caused transient variation in the hydraulic pressure within the xylem of branch segments. This local transient increase in pressure in the xylem was rapidly propagated along the vascular system in planta to the upper and lower regions of the stem. It was shown that this hydraulic pulse originates from the apoplast. Water that was mobilized in the hydraulic pulses came from the saturated porous material of the conduits and their walls, suggesting that the poroelastic behaviour of xylem might be a key factor. Although likely to be a generic mechanical response, quantitative differences in the hydraulic pulse were found in different species, possibly related to differences in xylem anatomy. Importantly the hydraulic pulse was proportional to the strained volume, similar to known thigmomorphogenetic responses. It is hypothesized that the hydraulic pulse may be the signal that rapidly transmits mechanobiological information to leaves, roots, and apices.

  18. Exploring glacier dynamics with subglacial water pressure pulses: Evidence for self-organized criticality?

    Science.gov (United States)

    Kavanaugh, J. L.

    2009-03-01

    In order to determine whether brief excursions, or "pulses," in subglacial water pressure inferred by Kavanaugh and Clarke (2000, 2001) occur, water pressures at the bed of Trapridge Glacier, Yukon, Canada, were recorded using an interface board that continuously monitored a pressure transducer. During the 231 day period between 16 July 2005 and 4 March 2006, more than 7000 pressure pulses were recorded, with magnitudes reaching nearly 3 times the flotation value. Comparison of the pressure pulse record with those from a number of other instruments installed in this soft-bedded glacier indicates that these pulses are generated by stress transients that compress the water within the borehole; calculations suggest that these transients are as large as 75 times the nominal driving stress. Both the magnitudes and interevent times for these pulses are well fitted by power law distributions that are remarkably similar to those exhibited by earthquakes. These similarities suggest that the ice-bed interface of a soft-bedded glacier behaves much like an earthquake fault and raises the possibility that such glaciers self-organize to a critical state. Further evidence for self-organized criticality (SOC) of soft-bedded glaciers is suggested by an examination of well-known ice dynamical properties and the rheological properties of subglacial sediments, which suggests that SOC might be a natural consequence of the rate-independent behavior of subglacial sediments.

  19. High-pressure dielectric barrier discharge Xenon lamps generating short pulses of high-peak-power VUV radiation (172nm) with high pulse-to-pulse reproducibility.

    Science.gov (United States)

    Carman, Robert; Ward, Barry; Mildren, Richard; Kane, Deborah

    2003-10-01

    Dielectric barrier discharges (DBDs) are used to efficiently generate radiation in the ultraviolet and vacuum-ultraviolet spectral regions (88nm-350nm) by forming rare-gas and rare-gas halide excimers in a transient plasma. Usually, DBD lamps generate the light output quasi-continuously or in bursts with a high degree of stochastic or random variability in the instantaneous UV/VUV intensity. However, regular pulses of high-peak-power UV/VUV, with high pulse-to-pulse reproducibility, are of interest for applications in biology, surface treatment and cleaning, and time-resolved fluorescence spectroscopy. Such pulses can be generated from spatially homogeneous plasmas in a Xe DBD when the discharge is driven by uni-polar voltage pulses of short duration ( 100ns)^1. In the present study, we will report Xe DBD lamp performance and VUV output pulse characteristics for gas pressures up to 2.5bar and excitation conditions tailored for high-peak-power output. The experimental results will be compared to theoretical results from a detailed 1-D computer model of the spatio-temporal evolution of the plasma kinetics and Xe species population densities. ^1R.P.Mildren and R.J.Carman, J.Phys.D, 34, L1-L6, (2001)

  20. Study of relationship between pulse pressure and mortality from all the causes, CVD and CVA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective: To determine the relationship between pulse pressure and mortality from all the causes: CVD and CVA. Methods: The cohort consisted of the beneficiaries from Korea Medical Insurance Corporation (KMIC) aged 40 and older who had taken health examination and completed the questionnaire inquiring of health habits and past medical history in 1992 or 1993. The number of cohort members was 698,796, and they were followed up from 1st January, 1994 until 31st December, 2000. The primary sources of the data used in this study were the death benefit record and health examination file of KMIC. In the case that the information about the cause of death was unknown in the death benefit record, it was checked from the death registry of National statistical Office and the inpatient data of KMIC. There were 37439 deaths during the follow-up period. Results: A linear relationship between pulse pressure and mortality from all the causes, cardiovascular disease and cerebrovascular disease, was determined in both genders, the whole population and age groups, in the hypertensive and normotensive ( P< 0. 01). Pulse pressure and mortality from all the causes, CVD and CVA increased ( P <0.01). Pulse pressure was significantly associated with a relatively high risk of mortality from all the causes, CVD and CVA in the whole population, both genders, all age groups, the hypertensive and normotensive after adjusted to age, gender, body mass index, blood sugar, serum total cholesterol, AST, ALT, urine protein, urine glucose, alcohol drinking and cigarette smoking ( P< 0.01). Conclusion: Pulse pressure shows linear relationship with the mortality from all the causes,CVD and CVA. Pulse pressure appears to be a single measure of blood pressure in predicting mortality from all the causes,CVD and CVA, even in the hypertensive and normotensive.

  1. Continuous cuff-less blood pressure monitoring based on the pulse arrival time approach: the impact of posture.

    Science.gov (United States)

    Muehlsteff, J; Aubert, X A; Morren, G

    2008-01-01

    There is an unmet need for cuff-less blood pressure (BP) monitoring especially, in personal healthcare applications. The pulse arrival time (PAT) approach might offer a suitable solution to enable comfortable BP monitoring even at beat-level. However, the methodology is based on hemodynamic surrogate measures, which are sensitive to patient activities such as posture changes, not necessarily related to blood pressure variations. In this paper, we analyze the impact of posture on the PAT measure and related hemodynamic parameters such as the pre-ejection period in well-defined procedures. Additionally, the PAT of a monitored subject is investigated in an unsupervised scenario illustrating the complexity of such a measurement. Our results show the failure of blood pressure inference based on simple calibration strategies using the PAT measure only. We discuss opportunities to compensate for the observed effects towards the realization of wearable cuff-less blood pressure monitoring. These findings emphasize the importance of accessing context information in personal healthcare applications, where vital sign monitoring is typically unsupervised.

  2. Phylloquinone (vitamin K₁) intake and pulse pressure as a measure of arterial stiffness in older adults.

    Science.gov (United States)

    Vaccaro, Joan A; Huffman, Fatma G

    2013-01-01

    This study examined the relationships among ethnicity/race, lifestyle factors, phylloquinone (vitamin K₁) intake, and arterial pulse pressure in a nationally representative sample of older adults from four ethnic/racial groups: non-Hispanic Whites, non-Hispanic Blacks, Mexican Americans, and other Hispanics. This was a cross-sectional study of U.S. representative sample with data from the National Health and Nutrition Examination Surveys, 2007-2008 and 2009-2010 of adults aged 50 years and older (N = 5296). Vitamin K intake was determined by 24-hour recall. Pulse pressure was calculated as the difference between the averages of systolic blood pressure and diastolic blood pressure. Compared to White non-Hispanics, the other ethnic/racial groups were more likely to have inadequate vitamin K₁ intake. Inadequate vitamin K₁ intake was an independent predictor of high arterial pulse pressure. This was the first study that compared vitamin K₁ inadequacy with arterial pulse pressure across ethnicities/races in U.S. older adults. These findings suggest that vitamin K screening may be a beneficial marker for the health of older adults.

  3. Ionospheric Response to Solar Wind Pressure Pulses Under Northward IMF Conditions

    Directory of Open Access Journals (Sweden)

    Kan Liou

    2013-01-01

    Full Text Available Enhancements of aurora and auroral electrojets in response to sudden compression of the magnetosphere by shocks/pressure pulses are well known and have been attributed by some to compression-enhanced magnetic field reconnection. To examine such a view, we analyze a fortuitous event that is comprised of a series of pressure pulses (< 20 min on November 8, 2000. These pressure pulses were preceded by a large, northward interplanetary magnetic field (IMF that lasted more than 15 hours such that effects from reconnection can be minimized. Auroral images acquired by ultraviolet imager on board the Polar satellite clearly show intensifications of the aurora that occurred first near local noon and progressively extended from dayside to nightside. The area-integrated global auroral power reached ~30 gigawatts (GW. It is also found that the global auroral power is well correlated with the solar wind dynamic pressure (correlation coefficient r ~0.90, rather than the change in the solar wind dynamic pressure. In-situ measurements of particle data from the Defense Meteorological Satellite Program satellite indicate that the magnetospheric source for the pressure-enhanced auroras is most likely the central plasma sheet. Other ionospheric parameters such as the auroral electrojet (AE index, magnetic storm index (Sym-H, and the cross polarcap potential drop also show a one-to-one correspondence to the pressure pulses. In one instance the auroral electrojets AE index reached more than 200 nT, the cross polar-cap potential drop (ÎŚpc inferred from the SuperDARN radar network ionospheric plasma convection increased to ~60 kV. The observed increases in the auroral emissions, AE, and polar cap potential were not associated with substorms. Our result strongly suggests that solar wind pressure pulses are an important source of geomagnetic activity during northward IMF periods.

  4. Experimental verification of the ablation pressure dependence upon the laser intensity at pulsed irradiation of metals

    Science.gov (United States)

    Krasyuk, I. K.; Semenov, A. Yu; Stuchebryukhov, I. A.; Khishchenko, K. V.

    2016-11-01

    Experiments for verification of a functional dependence of the ablation pressure on the irradiated surface of a target upon the laser intensity in a range from 1.2 to 350 TW/cm2 have been carried out. For that, at some intensities of the laser irradiation, time intervals between the laser pulse maximum and the moment of the shock-wave front arrival to the rear surface of the target were measured, which are dependent on the ablation pressure. Two schemes of the measurements were used. At the first scheme, at higher laser intensities, the front arrival moment is determined via an electron-optical camera when the rear surface begins glowing. At the second scheme, the front arrival moment is recorded when a probe laser pulse changes the character of the reflection by the rear surface of the irradiated target. Results of measurements are in agreement with the ablation pressure dependence upon the laser pulse intensity within 20%.

  5. Influence of Pulse Pressure on Seed Quality and Yield of Buckwheat (Fagopyrum esculentum Moench.

    Directory of Open Access Journals (Sweden)

    Elena Nefed'eva

    2013-09-01

    Full Text Available A method of pre-sowing treatment of seeds by pulse pressure which is characterized by high intensity and accuracy of dosage has been proposed. Pulse pressures in the range of 11-29 MPa did not lead to acute lethality determined by phosphorescence at room temperature. So there was no elimination of unproductive individuals but pulse pressure stimulated physiological processes in seeds and plants, leading to increased yield. Changes of germination, growth, and distribution of substances as well as plant productivity were observed. Generalization and analysis of experimental results demonstrated zones in dose-dependent area, such as the zone of hormesis (11-17 MPa, transitional zone (20-26 MPa and stress zone (29 MPa and more.

  6. Applications of tunable high energy/pressure pulsed lasers to atmospheric transmission and remote sensing

    Science.gov (United States)

    Hess, R. V.; Seals, R. K.

    1974-01-01

    Atmospheric transmission of high energy C12 O2(16) lasers were improved by pulsed high pressure operation which, due to pressure broadening of laser lines, permits tuning the laser 'off' atmospheric C12 O2(16) absorption lines. Pronounced improvement is shown for horizontal transmission at altitudes above several kilometers, and for vertical transmission through the entire atmosphere. The atmospheric transmission of tuned C12 O2(16) lasers compares favorably with C12 O2(18) isotope lasers and CO lasers. The advantages of tunable, high energy, high pressure pulsed lasers over tunable diode lasers and waveguide lasers, in combining high energies with a large tuning range, are evaluated for certain applications to remote sensing of atmospheric constituents and pollutants. Pulsed operation considerably increases the signal to noise ratio without seriously affecting the high spectral resolution of signal detection obtained with laser heterodyning.

  7. Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

    CERN Document Server

    Troyer, G L

    2000-01-01

    High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse r...

  8. Pulse pressure variation to predict fluid responsiveness in spontaneously breathing patients: tidal vs. forced inspiratory breathing.

    Science.gov (United States)

    Hong, D M; Lee, J M; Seo, J H; Min, J J; Jeon, Y; Bahk, J H

    2014-07-01

    We evaluated whether pulse pressure variation can predict fluid responsiveness in spontaneously breathing patients. Fifty-nine elective thoracic surgical patients were studied before induction of general anaesthesia. After volume expansion with hydroxyethyl starch 6 ml.kg(-1) , patients were defined as responders by a ≥ 15% increase in the cardiac index. Haemodynamic variables were measured before and after volume expansion and pulse pressure variations were calculated during tidal breathing and during forced inspiratory breathing. Median (IQR [range]) pulse pressure variation during forced inspiratory breathing was significantly higher in responders (n = 29) than in non-responders (n = 30) before volume expansion (18.2 (IQR 14.7-18.2 [9.3-31.3])% vs. 10.1 (IQR 8.3-12.6 [4.8-21.1])%, respectively, p breathing could predict fluid responsiveness (area under the curve 0.910, p breathing can be used to guide fluid management in spontaneously breathing patients.

  9. Needling Neiguan (P 6) for Treatment of Low Pulse Pressure Syndrome-- A Report of 31 Cases

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective: To observe the impact of needling Neiguan (P 6) on the cardiovascular functional status in low pulse pressure syndrome. Method: 49 eligible patients were randomly assigned to a acupuncture group with bilateral Neiguan (P 6) needled for successive 3 days, and a medication group given a daily 20 mL of Shenmai Injectio intravenously dripped for successive 6 days. The blood pressure, pulse pressure, stroke volume (SV), cardiac output(CO)/min, left ventricle work index (LVWI), mean arterial pressure (MAP), total peripheral resistance (TPR), coronary perfusion pressure (CPP), pulmonary arterial wedge pressure (PAWP), effective blood volume (BV), blood viscosity (N), microcirculation half renewal rate (MHR), and cardiac muscle blood volume (CMBV) were determined before and after the treatment, which were compared with the parameters obtained in 23 healthy subjects. Results: The decreased pulse pressure of all patients before treatment (P<0.01) increased significantly after treatment (P<0.001). The levels of SV, CO, LVWI, PAWP, BV, MHR and CMBV were lowed when compared with the healthy subjects before treatment (P<0.01), but all of them significantly increased after treatment (P<0.01). The increased CPP, TPR and N before treatment (P<0.01) were decreased after treatment (P<0.01). Conclusion: The therapeutic effect of acupuncture at point Neiguan (P 6) was better than medication though some of the indexes showed no significant difference (P<0.05).

  10. Arterial pulse pressure amplification described by means of a nonlinear wave model: characterization of human aging

    Science.gov (United States)

    Alfonso, M.; Cymberknop, L.; Armentano, R.; Pessana, F.; Wray, S.; Legnani, W.

    2016-04-01

    The representation of blood pressure pulse as a combination of solitons captures many of the phenomena observed during its propagation along the systemic circulation. The aim of this work is to analyze the applicability of a compartmental model for propagation regarding the pressure pulse amplification associated with arterial aging. The model was applied to blood pressure waveforms that were synthesized using solitons, and then validated by waveforms obtained from individuals from differentiated age groups. Morphological changes were verified in the blood pressure waveform as a consequence of the aging process (i.e. due to the increase in arterial stiffness). These changes are the result of both a nonlinear interaction and the phenomena present in the propagation of nonlinear mechanic waves.

  11. Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia

    Science.gov (United States)

    2006-09-01

    Measurement of Stroke Volume Stroke volume (SV) was measured noninvasively using thoracic electrical bioimpedance (TEB). TEB was measured using four...tients who did not die. For the current study, we measured mean arterial blood pressure (MAP), pulse pressure (PP), SV, and muscle sympathetic nerve...hemorrhagic shock. The vital sign monitors placed in emergency transport vehicles provide the medic with routine measures of arterial systolic, diastolic and

  12. Role of Pulse Pressure and Geometry of Primary Entry Tear in Acute Type B Dissection Propagation.

    Science.gov (United States)

    Peelukhana, Srikara V; Wang, Yanmin; Berwick, Zachary; Kratzberg, Jarin; Krieger, Joshua; Roeder, Blayne; Cloughs, Rachel E; Hsiao, Albert; Chambers, Sean; Kassab, Ghassan S

    2016-08-10

    The hemodynamic and geometric factors leading to propagation of acute Type B dissections are poorly understood. The objective is to elucidate whether geometric and hemodynamic parameters increase the predilection for aortic dissection propagation. A pulse duplicator set-up was used on porcine aorta with a single entry tear. Mean pressures of 100 and 180 mmHg were used, with pulse pressures ranging from 40 to 200 mmHg. The propagation for varying geometric conditions (%circumference of the entry tear: 15-65%, axial length: 0.5-3.2 cm) were tested for two flap thicknesses (1/3rd and 2/3rd of the thickness of vessel wall, respectively). To assess the effect of pulse and mean pressure on flap dynamics, the %true lumen (TL) cross-sectional area of the entry tear were compared. The % circumference for propagation of thin flap (47 ± 1%) was not significantly different (p = 0.14) from thick flap (44 ± 2%). On the contrary, the axial length of propagation for thin flap (2.57 ± 0.15 cm) was significantly different (p propagation was calculated as 75 ± 9 J/m(2) and was fairly uniform across different specimens. Pulse pressure had a significant effect on the flap movement in contrast to mean pressure. Hence, mitigation of pulse pressure and restriction of flap movement may be beneficial in patients with type B acute dissections.

  13. Influence of aerobic exercise training on post-exercise responses of aortic pulse pressure and augmentation pressure in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Nobuhiko eAkazawa

    2015-10-01

    Full Text Available Central arterial blood pressure (BP is more predictive of future cardiovascular events than is brachial BP because it reflects the BP load imposed on the left ventricle with greater accuracy. However, little is known about the effects of exercise training on central hemodynamic response to acute exercise. The purpose of the present study was to determine the influence of an aerobic exercise regimen on the response of aortic BP after a single aerobic exercise in postmenopausal women. Nine healthy postmenopausal women (age: 61 ± 2 years participated in a 12-week aerobic exercise training regimen. Before and after the training, each subjects performed a single bout of cycling at ventilatory thresholds for 30 min. We evaluated the post-exercise aortic BP response, which was estimated via the general transfer function from applanation tonometry. After the initial pre-training aerobic exercise session, aortic BP did not change significantly: however, aortic pulse pressure and augmentation pressure were significantly attenuated after the single aerobic exercise session following the 12-week training regimen. The present study demonstrated that a regular aerobic exercise training regimen induced the post-exercise reduction of aortic pulse pressure and augmentation pressure. Regular aerobic exercise training may enhance post-exercise reduction in aortic BP.

  14. Simultaneously Propagating Voltage and Pressure Pulses in Lipid Monolayers of pork brain and synthetic lipids

    CERN Document Server

    Griesbauer, J; Wixforth, A; Schneider, M F

    2012-01-01

    Hydrated interfaces are ubiquitous in biology and appear on all length scales from ions, individual molecules to membranes and cellular networks. In vivo, they comprise a high degree of self-organization and complex entanglement, which limits their experimental accessibility by smearing out the individual phenomenology. The Langmuir technique, however, allows the examination of defined interfaces, whose controllable thermodynamic state enables one to explore the proper state diagrams. Here we demonstrate that voltage and pressure pulses simultaneously propagate along monolayers comprised of either native pork brain or synthetic lipids. The excitation of pulses is conducted by the application of small droplets of acetic acid and monitored subsequently employing timeresolved Wilhelmy plate and Kelvin probe measurements. The isothermal state diagrams of the monolayers for both lateral pressure and surface potential are experimentally recorded, enabling us to predict dynamic voltage pulse amplitudes of 0,1 to 3mV...

  15. Evidence for the propagation of 2D pressure pulses in lipid monolayers near the phase transition

    CERN Document Server

    Griesbauer, J; Wixforth, A; Schneider, M F

    2012-01-01

    The existence and propagation of acoustic pressure pulses on lipid monolayers at the air/water-interfaces are directly observed by simple mechanical detection. The pulses are excited by small amounts of solvents added to the monolayer from the air phase. Employing a deliberate control of the lipid interface compressibility k, we can show that the pulses propagate at velocities, which are precisely reflecting the nonlinear behavior of the interface. This is manifested by a pronounced minimum of the sound velocity in the monolayer phase transition regime, while ranging up to 1.5 m/s at high lateral pressures. Motivated by the ubiquitous presence of lipid interfaces in biology, we propose the demonstrated sound propagation as an efficient and fast way of communication and protein modulation along nerves, between cells and biological units being controlled by the physical state of the interfaces.

  16. Arterial compliance in patients with cirrhosis: stroke volume-pulse pressure ratio as simplified index

    DEFF Research Database (Denmark)

    Fuglsang, S; Bendtsen, F; Christensen, E

    2001-01-01

    Arterial function may be altered in patients with cirrhosis. We determined compliance of the arterial tree (C(1)) in relation to systemic and splanchnic hemodynamic derangement and clinical variables. C(1) and the stroke volume-pulse pressure index (SV/PP) were significantly higher (+62% and +40%...... predictors of SV/PP (P abnormalities in the arterial compliance of these patients....

  17. REFLECTANCE PULSE OXIMETRY AT THE FOREHEAD IMPROVES BY PRESSURE ON THE PROBE

    NARCIS (Netherlands)

    DASSEL, ACM; GRAAFF, R; SIKKEMA, M; ZIJLSTRA, WG; AARNOUDSE, JG

    1995-01-01

    In this study, we investigated the possibility of improving reflectance (back-scatter) pulse oximetry measurements by pressure applied to the probe. Optimal signal detection, with the probe applied to an easily accessible location, is important to prevent erroneous oxygen saturation readouts. At the

  18. Consumer acceptance of high-pressure processing and pulsed-electric-field

    DEFF Research Database (Denmark)

    Olsen, Nina Veflen; Grunert, Klaus G.; Sonne, Anne-Mette

    2010-01-01

    has to offer, do not necessarily guarantee the success of a product in the market place. Consumer acceptance depends on whether consumers perceive that there are specific benefits associated with the product. This review focuses specifically on how high-pressure processing (HPP) and pulsed...

  19. Acetylcysteine reduces plasma homocysteine concentration and improves pulse pressure and endothelial function in patients with end-stage renal failure

    DEFF Research Database (Denmark)

    Scholze, Alexandra; Rinder, Christiane; Beige, Joachim;

    2004-01-01

    Increased oxidative stress, elevated plasma homocysteine concentration, increased pulse pressure, and impaired endothelial function constitute risk factors for increased mortality in patients with end-stage renal failure.......Increased oxidative stress, elevated plasma homocysteine concentration, increased pulse pressure, and impaired endothelial function constitute risk factors for increased mortality in patients with end-stage renal failure....

  20. The association of 25(OH)D with blood pressure, pulse pressure and carotid–radial pulse wave velocity in African women

    OpenAIRE

    Iolanthé M Kruger; Schutte, Aletta E.; Huisman, Hugo W.; Van Rooyen, Johannes M.; Schutte, Rudolph; Malan, Leoné; Malan, Nicolaas T.; Carla M T Fourie; Kruger, Annamarie

    2013-01-01

    High susceptibility of the African population to develop cardiovascular disease obliges us to investigate possible contributing risk factors. Our aim was to determine whether low 25(OH)D status is associated with increased blood pressure and carotid-radial pulse wave velocity in black South African women. We studied 291 urban women (mean age: 57.5669.00 yrs.). 25(OH)D status was determined by serum 25(OH)D levels. Women were stratified into sufficient (.30 ng/ ml), and insufficien...

  1. Compensation for the Effects of Ambient Conditions on the Calibration of Multi-Capillary Pressure Drop Standards

    Directory of Open Access Journals (Sweden)

    Colard S

    2014-12-01

    Full Text Available Cigarette draw resistance and filter pressure drop (PD are both major physical parameters for the tobacco industry. Therefore these parameters must be measured reliably. For these measurements, specific equipment calibrated with PD transfer standards is used. Each transfer standard must have a known and stable PD value, such standards usually being composed of several capillary tubes associated in parallel. However, PD values are modified by ambient conditions during calibration of such standards, i.e. by temperature and relative humidity (RH of air, and atmospheric pressure. In order to reduce the influence of these ambient factors, a simplified model was developed for compensating the effects of ambient conditions on the calibration of multi-capillary PD standards.

  2. Differing prognostic value of pulse pressure in patients with heart failure with reduced or preserved ejection fraction

    DEFF Research Database (Denmark)

    Jackson, Colette E.; Castagno, Davide; Maggioni, Aldo P.

    2015-01-01

    AIMS: Low pulse pressure is a marker of adverse outcome in patients with heart failure (HF) and reduced ejection fraction (HF-REF) but the prognostic value of pulse pressure in patients with HF and preserved ejection fraction (HF-PEF) is unknown. We examined the prognostic value of pulse pressure......) and 5008 with HF-PEF (828 deaths). Pulse pressure was analysed in quintiles in a multivariable model adjusted for the previously reported Meta-Analysis Global Group in Chronic Heart Failure prognostic variables. Heart failure and reduced ejection fraction patients in the lowest pulse pressure quintile had...... in patients with HF-PEF [ejection fraction (EF) ≥ 50%] and HF-REF. METHODS AND RESULTS: Data from 22 HF studies were examined. Preserved left ventricular ejection fraction (LVEF) was defined as LVEF ≥ 50%. All-cause mortality at 3 years was evaluated in 27 046 patients: 22 038 with HF-REF (4980 deaths...

  3. Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    TROYER, G.L.

    2000-08-25

    High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% {at} 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse rise time versus photo peak position and resolution. These data were collected to investigate the effect of pulse rise time compensation on resolution and efficiency.

  4. Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

    Directory of Open Access Journals (Sweden)

    Amann Matthias

    2007-11-01

    Full Text Available Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC measurement by the pulmonary artery catheter (PAC. However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU using COPAC as the method of reference. Methods We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 ± 18.8 years, who required both arterial and pulmonary artery pressure monitoring. COPAC measurements were performed at least every 4 hours and calculated as the average of 3 measurements, while COAP values were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman. Results A total of 164 coupled measurements were obtained. Absolute values of COPAC ranged from 2.80 to 10.80 l/min (mean 5.93 ± 1.55 l/min. The bias and limits of agreement between COPAC and COAP for unequal numbers of replicates was 0.02 ± 2.92 l/min. The percentage error between COPAC and COAP was 49.3%. The bias between percentage changes in COPAC (ΔCOPAC and percentage changes in COAP (ΔCOAP for consecutive measurements was -0.70% ± 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p PAC and ΔCOAP was 0.46 (p Conclusion Although the COAP algorithm shows a minimal bias with COPAC over a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore, the used algorithm (V 1.03 failed to

  5. Unconstrained pulse pressure monitoring for health management using hetero-core fiber optic sensor.

    Science.gov (United States)

    Nishiyama, Michiko; Sonobe, Masako; Watanabe, Kazuhiro

    2016-09-01

    In this paper, we present a pulse pressure waveform sensor that does not constrain a wearer's daily activity; the sensor uses hetero-core fiber optics. Hetero-core fiber sensors have been found to be sensitive to moderate bending. To detect minute pulse pressure changes from the radial artery at the wrist, we devised a fiber sensor arrangement using three-point bending supports. We analyzed and evaluated the measurement validity using wavelet transformation, which is well-suited for biological signal processing. It was confirmed that the detected pulse waveform had a fundamental mode frequency of around 1.25 Hz over the time-varying waveform. A band-pass filter with a range of frequencies from 0.85 to 1.7 Hz was used to pick up the fundamental mode. In addition, a high-pass filter with 0.85 Hz frequency eliminated arm motion artifacts; consequently, we achieved high signal-to-noise ratio. For unrestricted daily health management, it is desirable that pulse pressure monitoring can be achieved by simply placing a device on the hand without the sensor being noticed. Two types of arrangements were developed and demonstrated in which the pulse sensors were either embedded in a base, such as an armrest, or in a wearable device. A wearable device without cuff pressure using a sensitivity-enhanced fiber sensor was successfully achieved with a sensitivity of 0.07-0.3 dB with a noise floor lower than 0.01 dB for multiple subjects.

  6. Pulsed Discharge Effects on Bacteria Inactivation in Low-Pressure Radio-Frequency Oxygen Plasma

    Science.gov (United States)

    Vicoveanu, Dragos; Ohtsu, Yasunori; Fujita, Hiroharu

    2008-02-01

    The sporicidal effects of low-pressure radio frequency (RF) discharges in oxygen, produced by the application of continuous and pulsed RF power, were evaluated. For all cases, the survival curves showed a biphasic evolution. The maximum efficiency for bacteria sterilization was obtained when the RF power was injected in the continuous wave mode, while in the pulsed mode the lowest treatment temperature was ensured. The inactivation rates were calculated from the microorganism survival curves and their dependencies on the pulse characteristics (i.e., pulse frequency and duty cycle) were compared with those of the plasma parameters. The results indicated that the inactivation rate corresponding to the first phase of the survival curves is related to the time-averaged intensity of the light emission by the excited neutral atoms in the pulsed plasma, whereas the inactivation rate calculated from the second slope of the survival curves and the time-averaged plasma density have similar behaviors, when the pulse parameters were modified.

  7. Calibration Apparatus for Artillery Chamber Pressure Test Device Based on Environmental Factors%基于环境因子的火炮膛压测试仪校准装置

    Institute of Scientific and Technical Information of China (English)

    张瑜; 祖静; 张红艳; 马铁华

    2012-01-01

    In order to overcome the disadvantage of the simulation chamber calibration apparatus, such as complex structure,inconvenience and pressure range is too small, we improved the existing apparatus and established a new calibration system, The calibration system consisted of simulation chamber calibration apparatus, standard testing system, high and low temperature test equipment The artillery chamber pressure testing device could be calibrated by adopting environmental factors. The improved calibration apparatus could simulate the environment of high temperature and high pressure in gun chamber, the amplitude of the pressure signal generated by the apparatus was between 80~800 MPa, the pulse width of the pressure signal was between 10~20 ms,the rising time was less than 2 ms. Theory analysis and contrast test results showed that the calibration method for simulating application environment of it was reasonable. The sensitivity coefficients obtained by static calibration and calibration of simulation application environment were different The practical firing results showed that the data from the testing device after simulation environment calibration had better stability and high confidence level.%针对现有模拟膛压校准装置存在的结构复杂、操作不便及压力量程小等缺点,对现有装置进行了改进,建立了校准系统.校准系统由模拟膛压校准装置、标准检测系统及高低温实验箱组成,采用环境因子校准方法,可对火炮膛压测试仪实施校准.改进后的校准装置能模拟火炮膛内高温高压环境,产生的压力信号幅值在80~800 MPa,脉宽在10~20 ms,上升时间小于2 ms.理论分析与对比试验结果表明:火炮膛压测试仪在模拟应用环境下校准的方法是合理的,静态标定方法和模拟应用环境校准方法获得的测压器灵敏度系数不同,实炮测试数据表明经模拟应用环境校准后的测压器测试数据稳定性好,置信度高.

  8. Numerical predictions of pressure pulses in a Francis pump turbine with misali-gned guide vanes

    Institute of Scientific and Technical Information of China (English)

    肖业祥; 王正伟; 张瑾; 罗永要

    2014-01-01

    Previous experimental and numerical analyses of the pressure pulse characteristics in a Francis turbine are extended here by using the unsteady Reynolds-averaged Navier-Stokes equations with the shear stress transport (SST) turbulence model to model the unsteady flow within the entire flow passage of a large Francis pump turbine with misaligned guide vanes at the rated rotational speed. The S-curve characteristics are analyzed by a combined use of the model test and the steady state simulation with the aligned guide vane firstly. Four misaligned guide vanes with two different openings are chosen to analyze the influence of pressure pulses in the turbine. The characteristics of the dominant unsteady flow frequencies in different parts of the pump turbine for various misaligned guide vane openings are investigated in detail. The predicted hydraulic performance and the pressure fluctuations show that the misaligned guide vanes reduce the relative pressure fluctuation amplitudes in the stationary part of the flow passage, but not the runner blades. The misaligned guide vanes have changed the low frequencies in the entire flow passage with the change of the pulse amplitudes mainly due to changes in the rotor-stator interaction and the low frequency vortex rope flow behavior.

  9. Aluminum oxide films deposited in low pressure conditions by reactive pulsed dc magnetron sputtering

    CERN Document Server

    Seino, T

    2002-01-01

    The reactive pulsed dc sputtering technique is widely used for the deposition of oxide films. The operating pressure for sputtering is commonly above 0.13 Pa. In this study, however, aluminum oxide (alumina) films were deposited at operating pressures from 0.06 to 0.4 Pa using a sputtering system equipped with a scanning magnetron cathode and a pulsed dc power supply. The pulsed dc power was found to be useful not only to reduce arcing, but also to sustain the discharge at low pressure. The electrical breakdown field, intrinsic stress, O/Al ratio, refractive index, and surface roughness were investigated. Both a low intrinsic stress and an O/Al ratio around the stoichiometry were required to get the film having a high breakdown field. A low operating pressure of 0.1 Pa was found to provide the necessary stress and O/Al ratio targets. A 50-nm-thick alumina film having a maximum breakdown field of 7.4 MV/cm was obtained.

  10. Studies on an improved indigenous pressure wave generator and its testing with a pulse tube cooler

    Science.gov (United States)

    Jacob, S.; Karunanithi, R.; Narsimham, G. S. V. L.; Kranthi, J. Kumar; Damu, C.; Praveen, T.; Samir, M.; Mallappa, A.

    2014-01-01

    Earlier version of an indigenously developed Pressure Wave Generator (PWG) could not develop the necessary pressure ratio to satisfactorily operate a pulse tube cooler, largely due to high blow by losses in the piston cylinder seal gap and due to a few design deficiencies. Effect of different parameters like seal gap, piston diameter, piston stroke, moving mass and the piston back volume on the performance is studied analytically. Modifications were done to the PWG based on analysis and the performance is experimentally measured. A significant improvement in PWG performance is seen as a result of the modifications. The improved PWG is tested with the same pulse tube cooler but with different inertance tube configurations. A no load temperature of 130 K is achieved with an inertance tube configuration designed using Sage software. The delivered PV power is estimated to be 28.4 W which can produce a refrigeration of about 1 W at 80 K.

  11. Numerical simulation of pressure waves in the cochlea induced by a microwave pulse.

    Science.gov (United States)

    Yitzhak, Nir M; Ruppin, Raphael; Hareuveny, Ronen

    2014-10-01

    The pressure waves developing at the cochlea by the irradiation of the body with a plane wave microwave pulse are obtained by numerical simulation, employing a two-step finite-difference time-domain (FDTD) algorithm. First, the specific absorption rate (SAR) distribution is obtained by solving the Maxwell equations on a FDTD grid. Second, the temperature rise due to this SAR distribution is used to formulate the thermoelastic equations of motion, which are discretized and solved by the FDTD method. The calculations are performed for anatomically based full body human models, as well as for a head model. The dependence of the pressure amplitude at the cochlea on the frequency, the direction of propagation, and the polarization of the incident electromagnetic radiation, as well as on the pulse width, was investigated.

  12. Effect of high hydrostatic pressure, ultrasound and pulsed electric fields on milk composition and characteristics

    Directory of Open Access Journals (Sweden)

    Irena Jeličić

    2012-03-01

    Full Text Available High hydrostatic pressure, ultrasonication and pulsed eletrcic fields (PEF belong to novel food processing methods which are mostly implemented in combination with moderate temperatures and/ or in combination with each other in order to provide adequate microbiological quality with minimal losses of nutritional value. All of three mentioned methods have been intensively investigated for the purpose of inactivation and reduction of foodborne microorganisms present in milk and dairy products. However, a large number of scientific researches have been dedicated to investigation of impact of these methods on changes in constituents like milk fat, milk proteins and lactose as well as changes in mechanisms like renneting properties and coagulation of milk. The aim of this research was to give an overview of changes in milk constituents induced by high hydrostatic pressure, ultrasonification and pulsed electric field treatments as well as to suggest how these changes could improve conventional processes in the dairy industry.

  13. Impacts of air pressure on the evolution of nanosecond pulse discharge products

    Institute of Scientific and Technical Information of China (English)

    Yu Jin-Lu; He Li-Ming; Ding Wei; Wang Yu-Qian; Du Chun

    2013-01-01

    Based on the nonequilibrium plasma dynamics of air discharge,a dynamic model of zero-dimensional plasma is established by combining the component density equation,the Boltzmann equation,and the energy transfer equation.The evolution properties of nanosecond pulse discharge (NPD) plasma under different air pressures are calculated.The results show that the air pressure has significant impacts on the NPD products and the peak values of particle number density for particles such as O atoms,O3 molecules,N2(A3) molecules in excited states,and NO molecules.It increases at first and then decreases with the increase of air pressure.On the other hand,the peak values of particle number density for N2(B3)and N2(C3) molecules in excited states are only slightly affected by the air pressure.

  14. Damage of cellular material under simultaneous application of pressure and pulsed electric field

    CERN Document Server

    Bazhal, M I; Vorobev, E I

    2000-01-01

    Influence of pulsed electric field (PEF) simultaneous to pressure treatment on moisture expression from fine-cut cellular raw material has been investigated. Dependencies of specific conductivity $\\sigma$, liquid yield $Y$, instantaneous flow rate $v$ and qualitative juice characteristics at different modes of PEF treatment are discussed. Three main consolidation phases were observed in a case of mechanical expression. A unified approach is proposed for liquid yield data analysis allowing to reduce the data scattering caused by differences in the quality of samples. Simultaneous application of pressure and PEF treatment allows to reveal a passive form of electrical damage. Pressure provokes the damage of defected cells, enhances diffusion migration of moisture in porous cellular material and depresses the cell resealing processes. PEF application at a moment when a sample specific electrical conductivity reaches minimum and pressure achieves its constant value seemed to be the most optimal.

  15. Central blood pressure assessment using 24-hour brachial pulse wave analysis

    Directory of Open Access Journals (Sweden)

    Muiesan ML

    2014-10-01

    Full Text Available Maria Lorenza Muiesan, Massimo Salvetti, Fabio Bertacchini, Claudia Agabiti-Rosei, Giulia Maruelli, Efrem Colonetti, Anna Paini Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy Abstract: This review describes the use of central blood pressure (BP measurements during ambulatory monitoring, using noninvasive devices. The principles of measuring central BP by applanation tonometry and by oscillometry are reported, and information on device validation studies is described. The pathophysiological basis for the differences between brachial and aortic pressure is discussed. The currently available methods for central aortic pressure measurement are relatively accurate, and their use has important clinical implications, such as improving diagnostic and prognostic stratification of hypertension and providing a more accurate assessment of the effect of treatment on BP. Keywords: aortic blood pressure measurements, ambulatory monitoring, pulse wave analysis

  16. Outcome-driven thresholds for ambulatory pulse pressure in 9938 participants recruited from 11 populations

    DEFF Research Database (Denmark)

    Gu, Yu-Mei; Thijs, Lutgarde; Li, Yan

    2014-01-01

    Evidence-based thresholds for risk stratification based on pulse pressure (PP) are currently unavailable. To derive outcome-driven thresholds for the 24-hour ambulatory PP, we analyzed 9938 participants randomly recruited from 11 populations (47.3% women). After age stratification (... years) and using average risk as reference, we computed multivariable-adjusted hazard ratios (HRs) to assess risk by tenths of the PP distribution or risk associated with stepwise increasing (+1 mm Hg) PP levels. All adjustments included mean arterial pressure. Among 6028 younger participants (68 853...

  17. Modeling of asymmetric pulsed phenomena in dielectric-barrier atmospheric-pressure glow discharges

    Energy Technology Data Exchange (ETDEWEB)

    Ha Yan [College of Mathematics and Computer Science, Hebei University, Baoding 071002 (China); Wang Huijuan [School of Mathematics and Physics, North China Electric Power University, Baoding 071003 (China); Wang Xiaofei [College of Physics Science and Technology, Hebei University, Baoding 071002 (China)

    2012-01-15

    Asymmetric current pulses in dielectric-barrier atmospheric-pressure glow discharges are investigated by a self-consistent, one-dimensional fluid model. It is found that the glow mode and Townsend mode can coexist in the asymmetric discharge even though the gas gap is rather large. The reason for this phenomenon is that the residual space charge plays the role of anode and reduces the gap width, resulting in the formation of a Townsend discharge.

  18. Arterial compliance in patients with cirrhosis: stroke volume-pulse pressure ratio as simplified index

    DEFF Research Database (Denmark)

    Henriksen, J H; Fuglsang, Stefan; Bendtsen, Flemming;

    2001-01-01

    Arterial function may be altered in patients with cirrhosis. We determined compliance of the arterial tree (C(1)) in relation to systemic and splanchnic hemodynamic derangement and clinical variables. C(1) and the stroke volume-pulse pressure index (SV/PP) were significantly higher (+62% and +40...... predictors of SV/PP (P index seems to reflect abnormalities in the arterial compliance of these patients....

  19. A Neural Network for Estimation of Aortic Pressure from the Radial Artery Pressure Pulse

    Science.gov (United States)

    2001-10-25

    from periphery to artery: a model based study, American Journal of Physiology, 1998,274:43, pp H1386-92 [9] C. Chen, E. Nevo , B Fetics, P Pak, F, Yin, L...36. [10] B Fetics, E Nevo , C. Chen, D Kass, Parametric model derivation of transfer function for noninvasive estimation of aortic pressure by radial

  20. The Dynamic Calibration Method of High-Pressure Transducer under High-Static Pressure%高压传感器在高静压下的动态校准方法

    Institute of Scientific and Technical Information of China (English)

    张瑜; 裴东兴; 祖静

    2011-01-01

    提出了一种校准高压传感器频响特性的方法,动态校准系统主要由甘油油腔、霍普金森杆、气枪、应变片、电荷放大器、活塞式压力计和数据采集系统等组成.校准时先利用活塞式压力计在封闭式油腔中产生高静压,高静压作用于被校准的压力传感器.气枪发射子弹,子弹撞击霍普金森杆产生近似于冲激函数的窄脉冲应力波,应力波通过甘油传播并激励传感器,数据采集系统同时采集激励信号和传感器的输出信号,最后计算出被校传感器的频响特性.分析了瞬态信号的脉宽与频率校准范围的关系.该校准方法是高压测试系统动态校准的理想方法,实现了高压下压力传感器的动态校准,可校准的下限频率严格地达到零频,为动态高压测试提供有效的计量手段.%A dynamic calibration method of frequency response characteristics of high-pressure sensor is proposed. The calibration system mainly consists of an oil chamber full of glycerin,a Hopkinson bar,an air gun with its fire as sociated apparatuses,a strain gauge,a charge amplifier,a piston gauge and a data acquisition system. In process of the calibration,as a high hydrostatic pressure is applied to the sensor by a piston gauge and a enclosed oil chamber, the air gun-sjioots a bullet to strike Hopkinson bar that a stress wave will be formed. This stress wave is a narrow pulse signal for exciting sensor,I. E. Quasi-8 function. The stress wave propagation through glycerin and excited the sensor. The high precision data acquisition system collected the excited signal and sensor outputs signal and calculated the frequency response of the sensor. The relation between pulse-width of transient signal and calibrating frequency range was analyzed. This calibration method is an ideal method for high pressure sensor,it can realize the low limit frequency of the calibrated frequency range strictly reaches to the frequency of zero Hertz; and it

  1. Film dosimetry calibration method for pulsed-dose-rate brachytherapy with an 192Ir source.

    Science.gov (United States)

    Schwob, Nathan; Orion, Itzhak

    2007-05-01

    192Ir sources have been widely used in clinical brachytherapy. An important challenge is to perform dosimetric measurements close to the source despite the steep dose gradient. The common, inexpensive silver halide film is a classic two-dimensional integrator dosimeter and would be an attractive solution for these dose measurements. The main disadvantage of film dosimetry is the film response to the low-energy photon. Since the photon energy spectrum is known to vary with depth, the sensitometric curves are expected to be dependent on depth. The purpose of this study is to suggest a correction method for silver halide film dosimetry that overcomes the response changes at different depths. Sensitometric curves have been obtained at different depths with verification film near a 1 Ci 192Ir pulsed-dose-rate source. The depth dependence of the film response was observed and a correction function was established. The suitability of the method was tested through measurement of the radial dose profile and radial dose function. The results were compared to Monte Carlo-simulated values according to the TG43 formalism. Monte Carlo simulations were performed separately for the beta and gamma source emissions, using the EGS4 code system, including the low-energy photon and electron transport optimization procedures. The beta source emission simulation showed that the beta dose contribution could be neglected and therefore the film-depth dependence could not be attributed to this part of the source radioactivity. The gamma source emission simulations included photon-spectra collection at several depths. The results showed a depth-dependent softening of the photon spectrum that can explain the film-energy dependence.

  2. Application of Pressure Pulse Test Analysis in CO2 Leakage Detection and Monitoring

    Science.gov (United States)

    Shakiba, M.; Hosseini, S. A.

    2015-12-01

    Over the past decade, numerous research and industrial projects have been devoted to investigate the feasibility and efficiency of carbon dioxide capture, storage, and utilization. Besides the studies over the characteristics of candidate formations for CO2 injection, much attention has been paid to answer the environmental concerns regarding the CO2 leak to overlying formations. To first detect and then track a possible CO2 leak, different techniques have been proposed in the literature; however, most of them examine only a small portion of the formation and have a low resolution for early leak detection. To further increase the extent of the investigation zone and to monitor a large section of the formation in more detail, multi-well testing techniques have received a significant attention. Pressure pulse testing is a multi-well test technique in which a pressure signal generated by periods of injection and shut-in from a pulser well is propagated inside the formation, and the corresponding response is recorded at the observer wells. The recorded pressure response is then analyzed to measure the rock and fluid properties and to monitor the possible changes over the time. In this research study, we have applied frequency methods as well as superposition principle to interpret the pressure pulse test data and monitor the changes in transmissibility and storativity of the formation between the well pairs. We have used synthetic reservoir models and numerical reservoir simulations to produce the pressure pulse test data. The analysis of the simulation results indicated that even a small amount of CO2 leak in the investigation zone can have a measurable effect on the calculated storativity and transmissibility factors. This can be of a great importance when an early leak detection is of interest. Moreover, when multiple wells are available in the formation, the distribution of the calculated parameters can visualize the extent of CO2 leak, which has a great

  3. Pressure effects during pulsed-laser deposition of barium titanate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalo, J.; Afonso, C.N. [Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Inst. de Optica; Gomez San Roman, R.; Perez Casero, R. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, 28049 Cantoblanco, Madrid (Spain); Perriere, J. [Groupe de Physique des Solides, Universites Paris VII et VI, URA 17 du CNRS, Tour 23, 2 Place Jussieu, 75251 Paris Cedex 05 (France)

    1998-05-01

    The composition and homogeneity of barium titanate films grown by pulsed-laser deposition at different substrate temperatures (room temperature, 700 C) and gas environments (O{sub 2},Ar) in a broad pressure range (10{sup -7}-1 mbar) are correlated to the plasma expansion dynamics. It is found that the deposited films present an excess of Ba in the intermediate pressure range (10{sup -2}pressure and the existence of scattering processes for distances (d) from the target lower than L{sub P} and the diffusion of the ejected species for L{sub P}

  4. Evaluation and calibration of a pulsed neutron method for total hydrogen determination in mineral and concrete samples

    Energy Technology Data Exchange (ETDEWEB)

    Bennun, L.; Santibanez, M. [Universidad de Concepcion, Laboratorio de Fisica Aplicada, Departamento de Fisica, P.O. Box 160c, Concepcion (Chile); Gomez, J. [Holcim (Costa Rica) S.A, Alajuela (Costa Rica); Santisteban, J.R. [Centro Atomico Bariloche e Instituto Balseiro, Bariloche Rio Negro (Argentina)

    2011-11-15

    We studied the feasibility of a nondestructive method to determine hydrogen concentrations in concrete and mineral samples. The amount of total hydrogen in the sample is directly related to the proportion of water included in the paste preparation; and also considers all subsequent processes which can add or remove hydrogen in a real sample (like rain, evaporation, etc.). The hydrogen proportion is a critical variable in the curing concrete process; its excess or deficiency impacts negatively in the quality of the final product. The proposed technique is based on a pulsed neutron source and the technical support of the time of flight, which allow discriminating epithermal neutrons interacting with hydrogen (inelastic scattering) from the elastic and quasi-isotropic scattering produced by other kinds of atoms. The method was externally calibrated in limestone rocks fragments (CaCO{sub 3}-main material used in cement fabrication) and in steel, allowing an easy retrieval of the required information. The technique's simplicity may facilitate the development of a mobile measuring device in order to make determinations ''in situ.'' In this paper, we describe the foundations of the proposed method and various analysis results. (orig.)

  5. Pulse Combustor Driven Pressure Gain Combustion for High Efficiency Gas Turbine Engines

    KAUST Repository

    Lisanti, Joel

    2017-02-01

    The gas turbine engine is an essential component of the global energy infrastructure which accounts for a significant portion of the total fossil fuel consumption in transportation and electric power generation sectors. For this reason there is significant interest in further increasing the efficiency and reducing the pollutant emissions of these devices. Conventional approaches to this goal, which include increasing the compression ratio, turbine inlet temperature, and turbine/compressor efficiency, have brought modern gas turbine engines near the limits of what may be achieved with the conventionally applied Brayton cycle. If a significant future step increase in gas turbine efficiency is to be realized some deviation from this convention is necessary. The pressure gain gas turbine concept is a well established new combustion technology that promises to provide a dramatic increase in gas turbine efficiency by replacing the isobaric heat addition process found in conventional technology with an isochoric process. The thermodynamic benefit of even a small increase in stagnation pressure across a gas turbine combustor translates to a significant increase in cycle efficiency. To date there have been a variety of methods proposed for achieving stagnation pressure gains across a gas turbine combustor and these concepts have seen a broad spectrum of levels of success. The following chapter provides an introduction to one of the proposed pressure gain methods that may be most easily realized in a practical application. This approach, known as pulse combustor driven pressure gain combustion, utilizes an acoustically resonant pulse combustor to approximate isochoric heat release and thus produce a rise in stagnation pressure.

  6. Numerical Study of Pulsed Dielectric Barrier Discharge at Atmospheric Pressure Under the Needle-Plate Electrode Configuration

    Institute of Scientific and Technical Information of China (English)

    WANG Yanhui; YE Huanhuan; ZHANG Jiao; WANG Qi; ZHANG Jie; WANG Dezhen

    2016-01-01

    In this paper,we study the characteristics of atmospheric-pressure pulsed dielectric barrier discharge (DBD) under the needle-plate electrode configuration using a one-dimensional self-consistent fluid model.The results show that,the DBDs driven by positive pulse,negative pulse and bipolar pulse possess different behaviors.Moreover,the two discharges appearing at the rising and the falling phases of per voltage pulse also have different discharge regimes.For the case of the positive pulse,the breakdown field is much lower than that of the negative pulse,and its propagation characteristic is different from the negative pulse DBD.When the DBD is driven by a bipolar pulse voltage,there exists the interaction between the positive and negative pulses,resulting in the decrease of the breakdown field of the negative pulse DBD and causing the change of the discharge behaviors.In addition,the effects of the discharge parameters on the behaviors of pulsed DBD in the needle-plate electrode configuration are also studied.

  7. The effects of pulse pressure from seismic water gun technology on Northern Pike

    Science.gov (United States)

    Gross, Jackson A.; Irvine, Kathryn M.; Wilmoth, Siri K.; Wagner, Tristany L.; Shields, Patrick A; Fox, Jeffrey R.

    2013-01-01

    We examined the efficacy of sound pressure pulses generated from a water gun for controlling invasive Northern Pike Esox lucius. Pulse pressures from two sizes of water guns were evaluated for their effects on individual fish placed at a predetermined random distance. Fish mortality from a 5,620.8-cm3 water gun (peak pressure source level = 252 dB referenced to 1 μP at 1 m) was assessed every 24 h for 168 h, and damage (intact, hematoma, or rupture) to the gas bladder, kidney, and liver was recorded. The experiment was replicated with a 1,966.4-cm3 water gun (peak pressure source level = 244 dB referenced to 1 μP at 1 m), but fish were euthanized immediately. The peak sound pressure level (SPLpeak), peak-to-peak sound pressure level (SPLp-p), and frequency spectrums were recorded, and the cumulative sound exposure level (SELcum) was subsequently calculated. The SPLpeak, SPLp-p, and SELcum were correlated, and values varied significantly by treatment group for both guns. Mortality increased and organ damage was greater with decreasing distance to the water gun. Mortality (31%) by 168 h was only observed for Northern Pike exhibiting the highest degree of organ damage. Mortality at 72 h and 168 h postexposure was associated with increasing SELcum above 195 dB. The minimum SELcum calculated for gas bladder rupture was 199 dB recorded at 9 m from the 5,620.8-cm3 water gun and 194 dB recorded at 6 m from the 1,966.4-cm3water gun. Among Northern Pike that were exposed to the large water gun, 100% of fish exposed at 3 and 6 m had ruptured gas bladders, and 86% exposed at 9 m had ruptured gas bladders. Among fish that were exposed to pulse pressures from the smaller water gun, 78% exhibited gas bladder rupture. Results from these initial controlled experiments underscore the potential of water guns as a tool for controlling Northern Pike.

  8. Plasma sterilization of polyethylene terephthalate bottles by pulsed corona discharge at atmospheric pressure.

    Science.gov (United States)

    Masaoka, Satoshi

    2007-06-01

    A pulsed power supply was used to generate a corona discharge on a polyethylene terephthalate bottle, to conduct plasma sterilization at atmospheric pressure. Before generating such a discharge, minute quantities of water were attached to the inner surface of the bottle and to the surface of a high voltage (HV) electrode inserted into the bottle. Next, high-voltage pulses of electricity were discharged between electrodes for 6.0s, while rotating the bottle. The resulting spore log reduction values of Bacillus subtilis and Aspergillus niger on the inner surface of the bottle were 5.5 and 6 or higher, respectively, and those on the HV electrode surface were each 6 or higher for both strains. The presence of the by-products gaseous ozone, hydrogen peroxide, and nitric ions resulting from the electrical discharge was confirmed.

  9. Nanosecond-timescale high-pressure gas discharge in a microwave pulse compressor

    Science.gov (United States)

    Shlapakovski, Anatoli; Beilin, Leonid; Krasik, Yakov

    2016-09-01

    The results of experimental and numerical studies of the microwave plasma discharge initiated by a nanosecond laser pulse are presented. The discharge is ignited in the pressurized gas filling the switch, which opens the charged resonant cavity, so that the accumulated microwave energy is rapidly released into a load. Fast-framing optical imaging showed that the plasma in the switch appears as filaments expanding along the RF electric field. The temporal evolution of the plasma density was derived from time-resolved spectroscopic measurements. With increasing microwave energy in the cavity, the plasma appears earlier in time after the laser beam enters the switch and its density rises more steeply reaching values which exceed 1016 cm-3 at a gas pressure of 2 .105 Pa. Numerical simulations were conducted using the gas conductivity model of plasma and representation of discharge origin by setting initial population of seed electrons treated by PIC algorithm. The results showed good agreement with the experiments and explained how the self-consistent dynamics of the plasma and RF fields determines the quality of microwave output pulses. In addition, the dynamics of the microwave energy absorption in the discharge plasma was studied. It was shown that at a high pressure, even with an unlimited rate of ionization, a significant portion of the stored energy, 20%, is lost. This work was partially supported by the BSF Grant No. 2012038.

  10. Issues in deep ocean collinear double-pulse laser induced breakdown spectroscopy: Dependence of emission intensity and inter-pulse delay on solution pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence-Snyder, Marion; Scaffidi, Jonathan P.; Pearman, William F.; Gordon, Christopher M.; Angel, S. Michael

    2014-09-01

    Double-pulse laser-induced breakdown spectroscopy (DP-LIBS) with a collinear laser beam orientation is shown for high-pressure bulk aqueous solutions (up to 50 bar) along with bubble and plasma images. These investigations reveal that the emission plasma is quenched much more rapidly in solution requiring much shorter detector gate delays than for typical LIBS measurements in air. Also, the emission is inversely proportional to solution pressure, and the most intense emission at all pressures occurs when the laser-induced vapor bubble is at a maximum diameter. It is also shown that the laser-induced bubble grows initially at the same rate for all solution pressures, collapsing more quickly as the pressure is increased. Intense emission is best obtained for conditions where the laser-induced bubble formed by the first laser pulse is small and spherically shaped. - Highlights: • Collinear double-pulse LIBS is shown for 50 bar bulk aqueous solutions. • LIBS plasma in solution is much more rapidly quenched than a LIBS plasma in air. • For DP LIBS, the emission is inversely proportional to solution pressure. • Laser-induced bubble growth rate is the same at all solution pressures. • Large spherical laser-induced bubbles produce the strongest DP LIBS emission.

  11. Particle Densities of the Atmospheric-Pressure Argon Plasmas Generated by the Pulsed Dielectric Barrier Discharges

    Science.gov (United States)

    Pan, Jie; Li, Li; Wang, Yunuan; Xiu, Xianwu; Wang, Chao; Song, Yuzhi

    2016-11-01

    Atmospheric-pressure argon plasmas have received increasing attention due to their high potential in many industrial and biomedical applications. In this paper, a 1-D fluid model is used for studying the particle density characteristics of the argon plasmas generated by the pulsed dielectric barrier discharges. The temporal evolutions of the axial particle density distributions are illustrated, and the influences of changing the main discharge conditions on the averaged particle densities are researched by independently varying the various discharge conditions. The calculation results show that the electron density and the ion density reach two peaks near the momentary cathodes during the rising and the falling edges of the pulsed voltage. Compared with the charged particle densities, the densities of the resonance state atom Arr and the metastable state atom Arm have more uniform axial distributions, reach higher maximums and decay more slowly. During the platform of the pulsed voltage and the time interval between the pulses, the densities of the excited state atom Ar* are far lower than those of the Arr or the Arm. The averaged particle densities of the different considered particles increase with the increases of the amplitude and the frequency of the pulsed voltage. Narrowing the discharge gap and increasing the relative dielectric constant of the dielectric also contribute to the increase of the averaged particle densities. The effects of reducing the discharge gap distance on the neutral particle densities are more significant than the influences on the charged particle densities. supported by Natural Science Foundation of Shandong Province, China (No. ZR2015AQ008), and Project of Shandong Province Higher Educational Science and Technology Program of China (No. J15LJ04)

  12. Synthesis of Crystalline Carbon Nitride Thin Films by Pulsed Arc Discharge at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    SHI Changyong; MA Zhibin

    2007-01-01

    The preparation of crystalline C3N4 films was investigated using pulsed arc discharge from mixed methanol and ammonia water at atmospheric pressure.The X-ray diffraction(XRD)patterns of the films prepared at a substrate temperature of 450℃ suggested that the film was composed of α-C3N4 and β-C3N4 crystallites.Raman spectra exhibited distinct peaks which are in good agreement with those predicted theoretically for C3N4 crystallites.

  13. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Duten, X; Redolfi, M; Aggadi, N; Vega, A; Hassouni, K, E-mail: duten@lspm.cnrs.fr [LSPM-CNRS UPR 3407, Universite Paris Nord, 90 Avenue J.B. Clement, 93430 Villetaneuse (France)

    2011-10-19

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  14. Full-density, net-shape powder consolidation using dynamic magnetic pulse pressures

    Science.gov (United States)

    Chelluri, Bhanu; Barber, John P.

    1999-07-01

    The full-density consolidation of powders into net-shape parts yields high green strength, low shrinkage, short sinter times, superior mechanical properties, and low manufacturing costs. The conventional lowcost, single-press, single-sinter process typically densifies powders at less than 65 percent green density. This article describes the Magnepress™ process, a powder-processing technique wherein pulsed magnetic pressures consolidate powders into full-density parts without admixed lubricants or binders. The Magnepress technique is especially suitable for producing net-shape products with radial symmetry (e.g., rods, cylindrical parts with internal features, tubular shapes, and high aspect-ratio specimens).

  15. Spatial and temporal evolutions of ozone in a nanosecond pulse corona discharge at atmospheric pressure

    Science.gov (United States)

    Duten, X.; Redolfi, M.; Aggadi, N.; Vega, A.; Hassouni, K.

    2011-10-01

    This paper deals with the experimental determination of the spatial and temporal evolutions of the ozone concentration in an atmospheric pressure pulsed plasma, working in the nanosecond regime. We observed that ozone was produced in the localized region of the streamer. The ozone transport requires a characteristic time well above the millisecond. The numerical modelling of the streamer expansion confirms that the hydrodynamic expansion of the filamentary discharge region during the streamer propagation does not lead to a significant transport of atomic oxygen and ozone. It appears therefore that only diffusional transport can take place, which requires a characteristic time of the order of 50 ms.

  16. Stable radiation pressure acceleration of ions by suppressing transverse Rayleigh-Taylor instability with multiple Gaussian pulses

    Science.gov (United States)

    Zhou, M. L.; Liu, B.; Hu, R. H.; Shou, Y. R.; Lin, C.; Lu, H. Y.; Lu, Y. R.; Gu, Y. Q.; Ma, W. J.; Yan, X. Q.

    2016-08-01

    In the case of a thin plasma slab accelerated by the radiation pressure of an ultra-intense laser pulse, the development of Rayleigh-Taylor instability (RTI) will destroy the acceleration structure and terminate the acceleration process much sooner than theoretical limit. In this paper, a new scheme using multiple Gaussian pulses for ion acceleration in a radiation pressure acceleration regime is investigated with particle-in-cell simulation. We found that with multiple Gaussian pulses, the instability could be efficiently suppressed and the divergence of the ion bunch is greatly reduced, resulting in a longer acceleration time and much more collimated ion bunch with higher energy than using a single Gaussian pulse. An analytical model is developed to describe the suppression of RTI at the laser-plasma interface. The model shows that the suppression of RTI is due to the introduction of the long wavelength mode RTI by the multiple Gaussian pulses.

  17. Accurate quantitative analysis of gold alloys using multi-pulse laser induced breakdown spectroscopy and a correlation-based calibration method

    Energy Technology Data Exchange (ETDEWEB)

    Galbacs, Gabor [Department of Inorganic and Analytical Chemistry, University of Szeged, 6720 Szeged, Dom ter 7. (Hungary)], E-mail: galbx@chem.u-szeged.hu; Jedlinszki, Nikoletta; Cseh, Gabor; Galbacs, Zoltan; Turi, Laszlo [Department of Inorganic and Analytical Chemistry, University of Szeged, 6720 Szeged, Dom ter 7. (Hungary)

    2008-05-15

    Multi-pulse laser induced breakdown spectroscopy (LIBS), in combination with the generalized linear correlation calibration method (GLCM), was applied to the quantitative analysis (fineness determination) of quaternary gold alloys. Accuracy and precision on the order of a few thousandths ( per mille ) was achieved. The analytical performance is directly comparable to that of the standard cupellation method (fire assay), but provides results within minutes and is virtually non-destructive, as it consumes only a few micrograms of the sample.

  18. Vapor film collapse triggered by external pressure pulse and the fragmentation of melt droplet in FCIs

    Institute of Scientific and Technical Information of China (English)

    LIN Qian; TONG Lili; CAO Xuewu; KRIVENTSEV Vladimir

    2008-01-01

    The fragmentation process of high-temperature molten drop is a key factor to determine the ratio heat transferred to power in FCIs,which estimates the possible damage degree during the hypothetical severe accident in the nuclear reactors.In this paper,the fragmentation process of melt droplet in FCIs is investigated by theoretic analysis.The fragmentation mechanism is studied when an external pressure pulse applied to a melt droplet,which is surrounded by vapor film.The vapor film collapse which induces fragmentation of melt droplet is analyzed and modeled.And then the generated pressure is calculated.The vapor film collapse model is introduced to fragmentation correlation,and the predicted fragment size is calculated and compared with experimental data.The result shows that the developed model can predict the diameter of fragments and can be used to calculate the fragmentation process appreciatively.

  19. Plasma polymerization of ethylene in an atmospheric pressure-pulsed discharge

    Science.gov (United States)

    Donohoe, K.; Wydeven, T.

    1979-01-01

    The polymerization of ethylene in an atmospheric pressure-pulsed discharge has been studied. Partial pressures of ethylene up to 4 kN/sq m were used with helium as a diluent. Deposition rates (on glass slides) were the same throughout the discharge volume over a wide range of operating conditions. These rates were in the 1-2 A/sec range. The films were clear, soft, and showed good adhesion to the glass substrates. Oligomers large enough to visibly scatter 637.8-nm light were observed in the gas phase under all conditions in which film deposition occurred. The experimental results suggest that Brownian diffusion of these oligomers was the rate-limiting step in the film deposition process.

  20. High-pressure pulsed avalanche discharges: Formulas for required preionization density and rate for homogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Brenning, N.; Axnaes, I.; Nilsson, J.O.; Eninger, J.E. [Royal Inst. of Tech., Stockholm (Sweden)

    1997-02-01

    The requirements on preionization for the formation of spatially homogeneous pulsed avalanche discharges are examined. The authors derive two formulas which apply in the case of a slowly rising electric field, one which gives the required preionization density at breakdown, and one which gives the required preionization rate. These quantities are expressed as functions of the electrochemical properties of the gas, the neutral density, and the electric field rise time. They also treat the statistical effect that the electrons tend to form groups, in contrast to being randomly distributed in space, during the prebreakdown phase. This process is found to increase the required preionization rate significantly, typically by a factor of five for a discharge at atmospheric pressure. Homogeneous high-pressure discharges have been used for laser excitation, and have also been proposed for chemical plasma processing (ozone production) because of their good scaling properties and high efficiency.

  1. Cuff-less blood pressure measurement using pulse arrival time and a Kalman filter

    Science.gov (United States)

    Zhang, Qiang; Chen, Xianxiang; Fang, Zhen; Xue, Yongjiao; Zhan, Qingyuan; Yang, Ting; Xia, Shanhong

    2017-02-01

    The present study designs an algorithm to increase the accuracy of continuous blood pressure (BP) estimation. Pulse arrival time (PAT) has been widely used for continuous BP estimation. However, because of motion artifact and physiological activities, PAT-based methods are often troubled with low BP estimation accuracy. This paper used a signal quality modified Kalman filter to track blood pressure changes. A Kalman filter guarantees that BP estimation value is optimal in the sense of minimizing the mean square error. We propose a joint signal quality indice to adjust the measurement noise covariance, pushing the Kalman filter to weigh more heavily on measurements from cleaner data. Twenty 2 h physiological data segments selected from the MIMIC II database were used to evaluate the performance. Compared with straightforward use of the PAT-based linear regression model, the proposed model achieved higher measurement accuracy. Due to low computation complexity, the proposed algorithm can be easily transplanted into wearable sensor devices.

  2. Ion motion effects on the generation of short-cycle relativistic laser pulses during radiation pressure acceleration

    Institute of Scientific and Technical Information of China (English)

    W.P.Wang; X.M.Zhang; X.F.Wang; X.Y.Zhao; J.C.Xu; Y.H.Yu; L.Q.Yi; Y.Shi; L.G.Zhang; T.J.Xu; C.Liu; Z.K.Pei; B.F.Shen

    2014-01-01

    The effects of ion motion on the generation of short-cycle relativistic laser pulses during radiation pressure acceleration are investigated by analytical modeling and particle-in-cell simulations. Studies show that the rear part of the transmitted pulse modulated by ion motion is sharper compared with the case of the electron shutter only. In this study, the ions further modulate the short-cycle pulses transmitted. A 3.9 fs laser pulse with an intensity of 1.33×1021W cm-2is generated by properly controlling the motions of the electron and ion in the simulations. The short-cycle laser pulse source proposed can be applied in the generation of single attosecond pulses and electron acceleration in a small bubble regime.

  3. A volume pulsed corona formed during nanosecond pulsed periodic discharge of negative polarity in narrow gaps with airflow at atmospheric pressure

    Science.gov (United States)

    Lepekhin, N. M.; Priseko, Yu. S.; Puresev, N. I.; Filippov, V. G.

    2014-06-01

    A volume mode of spatially homogeneous nanosecond pulsed-periodic corona discharge of negative polarity has been obtained using an edge-to-edge electrode geometry in narrow gaps with airflow at atmospheric pressure and natural humidity. The parameters of discharge are estimated, and a factor limiting the power deposited in discharge is determined.

  4. Study on the mode-transition of nanosecond-pulsed dielectric barrier discharge between uniform and filamentary by controlling pressures and pulse repetition frequencies

    Science.gov (United States)

    Yu, S.; Pei, X.; Hasnain, Q.; Nie, L.; Lu, X.

    2016-02-01

    In this paper, we investigate the temporally resolved evolution of the nanosecond pulsed dielectric barrier discharge (DBD) in a moderate 6 mm discharge gap under various pressures and pulse repetition frequencies (PRFs) by intensified charge-coupled device (ICCD) images, using dry air and its components oxygen and nitrogen. It is found that the pressures are very different when the mode transits between uniform and filamentary in air, oxygen, and nitrogen. The PRFs can also obviously affect the mode-transition. The transition mechanism in the pulsed DBD is not Townsend-to-Streamer, which is dominant in the traditional alternating-voltage DBD. The pulsed DBD in a uniform mode develops in the form of plane ionization wave due to overlap of primary avalanches, while the increase in pressure disturbs the overlap and discharge develops in streamer, corresponding to the filamentary mode. Increasing the initial electron density by pre-ionization may contribute to discharge uniformity at higher pressures. We also found that the dependence of homogeneity upon PRF is a non-monotonic one.

  5. Study on the mode-transition of nanosecond-pulsed dielectric barrier discharge between uniform and filamentary by controlling pressures and pulse repetition frequencies

    Science.gov (United States)

    Yu, Sizhe; Lu, Xinpei

    2016-09-01

    We investigate the temporally resolved evolution of the nanosecond pulsed dielectric barrier discharge (DBD) in a moderate 6mm gap under various pressures and pulse repetition frequencies (PRFs) by intensified charge-coupled device (ICCD) images, using synthetic air and its components oxygen and nitrogen. It is found that the pressures are very different when the DBD mode transits between uniform and filamentary in air, oxygen, and nitrogen. The PRFs can also obviously affect the mode-transition. The transition mechanism in the pulsed DBD is not Townsend-to-streamer, which is dominant in the traditional alternating-voltage DBDs. The pulsed DBD in a uniform mode develops in the form of plane ionization wave, due to overlap of primary avalanches, while the increase in pressure disturbs the overlap and DBD develops in streamer instead, corresponding to the filamentary mode. Increasing the initiatory electron density by pre-ionization methods may contribute to discharge uniformity at higher pressures. We also find that the dependence of uniformity upon PRF is non-monotonic.

  6. Plasma density enhancement in atmospheric-pressure dielectric-barrier discharges by high-voltage nanosecond pulse in the pulse-on period: a PIC simulation

    Science.gov (United States)

    Sang, Chaofeng; Sun, Jizhong; Wang, Dezhen

    2010-02-01

    A particle-in-cell (PIC) plus Monte Carlo collision simulation is employed to investigate how a sustainable atmospheric pressure single dielectric-barrier discharge responds to a high-voltage nanosecond pulse (HVNP) further applied to the metal electrode. The results show that the HVNP can significantly increase the plasma density in the pulse-on period. The ion-induced secondary electrons can give rise to avalanche ionization in the positive sheath, which widens the discharge region and enhances the plasma density drastically. However, the plasma density stops increasing as the applied pulse lasts over certain time; therefore, lengthening the pulse duration alone cannot improve the discharge efficiency further. Physical reasons for these phenomena are then discussed.

  7. Experimental investigation and calibration of surface pressure modeling for trailing edge noise

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2011-01-01

    The modeling of the surface pressure spectrum under a turbulent boundary layer is investigated in the presence of an adverse pressure gradient along the flow direction. It is shown that discrepancies between measurements and results from a well-known model increase as the pressure gradient...... increases. This model is modified by introducing anisotropy in the definition of the vertical velocity component spectrum across the boundary layer. The degree of anisotropy is directly related to the strength of the pressure gradient. It is shown that by appropriately normalizing the pressure gradient...... and by tuning the anisotropy factor, experimental results can be closely reproduced by the modified model....

  8. Ion kinetics and self pulsing in DC microplasma discharges at atmospheric and higher pressure

    Science.gov (United States)

    Mahamud, Rajib; Farouk, Tanvir I.

    2016-04-01

    Atmospheric pressure microplasma devices have been the subject of considerable interest and research during the last decade. Most of the operation regime of the plasma discharges studied fall in the ‘abnormal’, ‘normal’ and ‘corona’ modes—increasing and a ‘flat’ voltage current characteristics. However, the negative differential resistance regime at atmospheric and high pressures has been less studied and possesses unique characteristics that can be employed for novel applications. In this work, the role of ion kinetics especially associated with trace impurities; on the self pulsing behavior has been investigated. Detailed numerical simulations have been conducted with a validated model for a helium-nitrogen feed gas mixture. Different oscillatory modes were observed where the discharge was found to undergo complete or partial relaxation. Trace amount of nitrogen was found to significantly alter the pulsing characteristics. External parameters influencing these self oscillations are also studied and aspects of the ion kinetics on the oscillatory behavior are discussed.

  9. Effect of double false pulses in calibrated neutron coincidence collar during measuring time-correlated neutrons from PuBe neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tam Cong, E-mail: tam.nguyen.cong@energia.mta.hu; Huszti, Jozsef; Nguyen, Quan Van

    2015-09-01

    Effect of double false pulses of preamplifiers in neutron coincidence collar was investigated to explain non-parallel shape of calibrated D/S–M{sub Pu} curves of two commercial neutron coincidence collars, JCC-31 and JCC-13. Two curves, which were constructed from D/S ratio (doubles and singles count rate), and Pu content M{sub Pu}, of the same set of secondary standard PuBe neutron sources, should be parallel. Non-parallelism rises doubt about usability of the method based on this curve for determination of Pu content in PuBe neutron sources. We have shown in three steps that the problem originates from double false pulses of preamplifiers in JCC-13. First we used a pulse train diagram for analyzing the non-parallel shape, second we used Rossi-Alpha distribution measured by pulse train recorder developed in our institute and finally, we investigated the effect of inserted noise pulses. This implies a new type of QA test option in traditional multiplicity shift registers for excluding presence of double false pulses.

  10. A method for determining transverse permeability of tight reservoir cores by radial pressure pulse decay measurement

    Science.gov (United States)

    Yang, Zehao; Dong, Mingzhe; Zhang, Shaojie; Gong, Houjian; Li, Yajun; Long, Feifei

    2016-10-01

    A transverse pressure pulse decay (TPPD) method is presented to measure transverse permeability of tight reservoir cores in a cell with finite volume. Given appropriate assumptions, a mathematical model based on the specially designed experiment is formulated, and its general solution is proposed. Early-time and late-time techniques are further presented for convenient postprocessing applications of experimental data. Meanwhile, sensitivity analysis of TPPD method is given. It is found that a good TPPD experimental principle can be obtained by adjusting test gas, experimental pressure, dimension of core sample, and volume ratio (λ). The volume ratio error (λerror) analysis reveals the following: (1) a larger λerror results in increased transverse permeability error (kerror); (2) the volume ratio (λ) is better not very close to 0.754; (3) when λ is equal to or greater than 1, the kerror resulting from λerror is monotonic decreasing as the volume ratio increases. In practice, λ is usually equal to or greater than 1 due to the very small pore volume of a tight core. But this does not mean that the volume ratio should be as large as possible. The reason for this is that a pressure transducer with higher resolution is needed to record pressure change. That means experimental apparatus is much more costly. And such a TPPD experiment requires a much longer time to attain the late-time straight line behavior. The best choice is to find an optimal balance point among experimental cost, time, and accuracy.

  11. 压力仪表校验系统设计研究%Pressure gauge calibration system design research

    Institute of Scientific and Technical Information of China (English)

    刘玺

    2012-01-01

    首先介绍了当前行业内压力表校验系统的研究现状,并分析了当前压力仪表检定的发展方向,最后重点对压力仪表校验系统设计,从系统的需求分析出发进行了分析和研究.%This paper firstly introduces the current status of industry within pressure gauge calibration system application, through literature methodology, and analyzed the current pressure gauge verification research situation and developing direction. The research content is discussed on the basis of research of main purpose and topic research. With related system design theory of pressure gauge calibration system design, from the system of needs analysis, this paper summarized the system based on the basic function requirement. Through system design, this paper expounds the basic theory of system design should meet the basic principles.

  12. Intracranial pressure pulse waveform correlates with aqueductal cerebrospinal fluid stroke volume.

    Science.gov (United States)

    Hamilton, Robert; Baldwin, Kevin; Fuller, Jennifer; Vespa, Paul; Hu, Xiao; Bergsneider, Marvin

    2012-11-01

    This study identifies a novel relationship between cerebrospinal fluid (CSF) stroke volume through the cerebral aqueduct and the characteristic peaks of the intracranial pulse (ICP) waveform. ICP waveform analysis has become much more advanced in recent years; however, clinical practice remains restricted to mean ICP, mainly due to the lack of physiological understanding of the ICP waveform. Therefore, the present study set out to shed some light on the physiological meaning of ICP morphological metrics derived by the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm by investigating their relationships with a well defined physiological variable, i.e., the stroke volume of CSF through the cerebral aqueduct. Seven patients received both overnight ICP monitoring along with a phase-contrast MRI (PC-MRI) of the cerebral aqueduct to quantify aqueductal stroke volume (ASV). Waveform morphological analysis of the ICP signal was performed by the MOCAIP algorithm. Following extraction of morphological metrics from the ICP signal, nine temporal ICP metrics and two amplitude-based metrics were compared with the ASV via Spearman's rank correlation. Of the nine temporal metrics correlated with the ASV, only the width of the P2 region (ICP-Wi2) reached significance. Furthermore, both ICP pulse pressure amplitude and mean ICP did not reach significance. In this study, we showed the width of the second peak (ICP-Wi2) of an ICP pulse wave is positively related to the volume of CSF movement through the cerebral aqueduct. This finding is an initial step in bridging the gap between ICP waveform morphology research and clinical practice.

  13. A comparison of the failure times of pulse oximeters during blood pressure cuff-induced hypoperfusion in volunteers.

    Science.gov (United States)

    Kawagishi, Toshiya; Kanaya, Noriaki; Nakayama, Masayasu; Kurosawa, Saori; Namiki, Akiyoshi

    2004-09-01

    Important information may not be obtained if the pulse oximetry signal is lost during inflation of a cuff for blood pressure measurement, particularly in patients with hemodynamic instability. In the present study, we compared the failure times of pulse oximeters during cuff-induced hypoperfusion in volunteers. A pulse oximeter sensor was attached to the index finger, and a blood pressure cuff was attached to the same arm of each volunteer. MasimoSET Radical (Masimo), Nellcor N-395 (N-395), Nellcor N-20PA, and Nellcor D-25 were tested. To evaluate the failure time of each pulse oximeter, time to peak of cuff pressure, time to loss of signal, time to recovery of signal, and failure interval were measured. All measurements were performed three times for each pulse oximeter and were averaged. There were no differences in hemodynamic measurements among the groups. Time to loss of signal was longer in Masimo than the other pulse oximeters. Masimo and N-395 showed significantly shorter times to recovery of signal than those of the other two pulse oximeters. Failure interval was in the order of Masimo Masimo did not lose a signal as rapidly as the other oximeters studied. Masimo was similar in performance to the N-395 at providing useful data sooner than conventional technology after a loss of the signal. These observations suggest that data will be more available with fewer false-positive alarms when using the Masimo oximeter followed by the N-395 when compared with conventional oximeters.

  14. Efficacy of pulsed electromagnetic field therapy in healing of pressure ulcers: A randomized control trial

    Directory of Open Access Journals (Sweden)

    Gupta Anupam

    2009-12-01

    Full Text Available Background : Pressure ulcers are one of the most common complications in health care settings. Still there are no optimal protocols to manage the pressure ulcers. Aim : To assess the effectiveness of pulsed electromagnetic field therapy (PEMF in healing of pressure ulcers in patients with neurological disorders. Design : Randomized double blind control trial. Setting : Neurological rehabilitation department in a university research hospital. Participants : Twelve patients (M:F, 9:3 having neurological disorders, with age between 12-50 years (mean 30.16611.32 yrs and 24 pressure ulcers. Intervention : Six patients with 13 ulcers received PEMF therapy and the remaining 6 patients with 11 ulcers received sham treatment, for 30 sessions (45 minutes each using the equipment ′Pulsatron′. The frequency of PEMF was set at 1 Hz with sine waves and current intensity of 30 mili ampere. Whole body exposure was given in both the groups. Outcome Measures : Bates-Jensen wound assessment tool (BJWAT score was used as main outcome measure and scores at the end of session were compared with initial scores and analyzed. Similarly National Pressure Ulcer Advisory Panel (NPUAP scores were compared and analyzed as secondary outcome measure. Results : Thirteen ulcers were in stage IV and 11 were in stage III at the start of the study. Significant healing of ulcers was noted, BJWAT scores, in both the treatment and sham groups (P < 0.001 and 0.003 respectively at the completion of the study. However, when comparing between the groups, healing was not significant (P = 0.361. Similarly trend was noted with NPUAP scores with no significant difference between the treatment and sham groups (P = 0.649 at the completion of study. Conclusions : No significant difference in pressure ulcer healing was observed between PEMF treatment and sham group in this study.

  15. Using pressure pulse seismology to examine basal criticality and the influence of sticky spots on glacial flow

    Science.gov (United States)

    Kavanaugh, J. L.; Moore, P. L.; Dow, C. F.; Sanders, J. W.

    2010-12-01

    Here we report results of water pressure pulse studies conducted at Storglaciären (Sweden) and West Washmawapta Glacier (British Columbia, Canada). Comparison of pressure pulse records with meteorological conditions at Storglaciären indicates that several periods of increased basal slip activity observed during a 10 day interval of summer 2008 were due to precipitation loading of the glacier surface, rather than to infiltration of surface water to the glacier bed; this indicates that the glacier bed was close to the failure strength for much of this interval. Pressure pulse magnitudes for the two glaciers were well-fit by power law distributions similar to those earlier observed at Trapridge Glacier (and similar in form to the Gutenberg-Richter relationship commonly used in seismology), suggesting that the mechanical processes that give rise to these distributions are robust features of soft-bedded glaciers. In contrast, interevent time distributions for both glaciers diverge from those observed at Trapridge Glacier for short recurrence intervals, suggesting that the factors that govern the rate at which these processes occur differ between glaciers. An examination of pressure pulse characteristics at West Washmawapta Glacier indicates that the establishment of a basal drainage system in summer 2008 resulted in increased stability and reduced sensitivity to meltwater input, suggesting that common assumptions about the relationship between meltwater production and ice flow are oversimplified. These results demonstrate that water pressure pulse observations can provide valuable insight into the dynamics of soft-bedded glaciers.

  16. Comparison of different calibration approaches for chloramphenicol quantification in chicken muscle by ultra-high pressure liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Pan, Xiao-Dong; Jiang, Wei; Wu, Ping-Gu

    2015-01-07

    Matrix-dependent signal suppression often occurs in quantitative analysis by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In this study, we investigated three calibration methods for compensation of signal suppression on chloramphenicol (CAP) quantification in chicken muscle. The data showed that the spiking recoveries by solvent standard calibration with a stable isotope labelled internal standard (SIL-IS) and matrix-matched standard calibration with a SIL-IS were significantly higher than by external matrix-matched standard calibration (P 0.05). The limit of detection (LOD) for external matrix matched standard calibration was 0.1 μg kg(-1), and that for SIL-IS calibration (including matrix matched and solvent dissolved standard) was 0.03 μg kg(-1).

  17. Kinetic studies of NO formation in pulsed air-like low-pressure dc plasmas

    Science.gov (United States)

    Hübner, M.; Gortschakow, S.; Guaitella, O.; Marinov, D.; Rousseau, A.; Röpcke, J.; Loffhagen, D.

    2016-06-01

    The kinetics of the formation of NO in pulsed air-like dc plasmas at a pressure of 1.33 mbar and mean currents between 50 and 150 mA of discharge pulses with 5 ms duration has been investigated both experimentally and by self-consistent numerical modelling. Using time-resolved quantum cascade laser absorption spectroscopy, the densities of NO, NO2 and N2O have been measured in synthetic air as well as in air with 0.8% of NO2 and N2O, respectively. The temporal evolution of the NO density shows four distinct phases during the plasma pulse and the early afterglow in the three gas mixtures that were used. In particular, a steep density increase during the ignition phase and after termination of the discharge current pulse has been detected. The NO concentration has been found to reach a constant value of 0.57× {{10}14}~\\text{molecules}~\\text{c}{{\\text{m}}-3} , 1.05× {{10}14}~\\text{molecules}~\\text{c}{{\\text{m}}-3} , and 1.3× {{10}14}~\\text{molecules}~\\text{c}{{\\text{m}}-3} for mean plasma currents of 50 mA, 100 mA and 150 mA, respectively, in the afterglow. The measured densities of NO2 and N2O in the respective mixture decrease exponentially during the plasma pulse and remain almost constant in the afterglow, especially where the admixture of NO2 has a remarkable impact on the NO production during the ignition. The numerical results of the coupled solution of a set of rate equations for the various heavy particles and the time-dependent Boltzmann equation of the electrons agree quite well with the experimental findings for the different air-like plasmas. The main reaction processes have been analysed on the basis of the model calculations and the remaining differences between the experiment and modelling especially during the afterglow are discussed.

  18. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    OpenAIRE

    Pai, David,; Lacoste, Deanna,; Laux, C.

    2010-01-01

    International audience; In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determine...

  19. Analysis of the scintillation mechanism in a pressurized 4He fast neutron detector using pulse shape fitting

    OpenAIRE

    R.P. Kelley; Murer, D.; Ray, H.; K.A. Jordan

    2015-01-01

    An empirical investigation of the scintillation mechanism in a pressurized 4He gas fast neutron detector was conducted using pulse shape fitting. Scintillation signals from neutron interactions were measured and averaged to produce a single generic neutron pulse shape from both a 252Cf spontaneous fission source and a (d,d) neutron generator. An expression for light output over time was then developed by treating the decay of helium excited states in the same manner as the decay of radioactiv...

  20. Radiative heat transfer in plasma of pulsed high pressure caesium discharge

    Science.gov (United States)

    Lapshin, V. F.

    2016-01-01

    Two-temperature many component gas dynamic model is used for the analysis of features of radiative heat transfer in pulsed high pressure caesium discharge plasma. It is shown that at a sufficiently high pressure the radial optical thickness of arc column is close to unit (τR (λ) ∼ 1) in most part of spectrum. In this case radiative heat transfer has not local character. In these conditions the photons which are emitted in any point of plasma volume are absorbed in other point remote from an emission point on considerable distance. As a result, the most part of the electric energy put in the discharge mainly near its axis is almost instantly redistributed on all volume of discharge column. In such discharge radial profiles of temperature are smooth. In case of low pressure, when discharge plasma is optically transparent for own radiation in the most part of a spectrum (τR(λ) << 1), the emission of radiation without reabsorption takes place. Radiative heat transfer in plasma has local character and profiles of temperature have considerable gradient.

  1. Optical Properties Dependence with Gas Pressure in AlN Films Deposited by Pulsed Laser Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J A; Riascos, H [Departamento de Fisica, Universidad Tecnologica de Pereira, Grupo plasma Laser y Aplicaciones A.A 097 (Colombia); Caicedo, J C [Grupo pelIculas delgadas, Universidad del Valle, Cali (Colombia); Cabrera, G; Yate, L, E-mail: jcaicedoangulo@gmail.com [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain)

    2011-01-01

    AlN films were deposited by pulsed laser deposition technique (PLD) using an Nd: YAG laser ({lambda} = 1064 nm). The films were deposited in a nitrogen atmosphere as working gas; the target was an aluminum high purity (99.99%). The films were deposited with a laser fluence of 7 J/cm2 for 10 minutes on silicon (100) substrates. The substrate temperature was 300 deg. C and the working pressure was varied from 3 mtorr to 11 mtorr. The thickness measured by profilometer was 150 nm for all films. The crystallinity was observed via XRD pattern, the morphology and composition of the films were studied using scanning electron microscopy (SEM) and Energy Dispersive X-ray analysis (EDX), respectively. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range of 400 cm-1- 900 cm-1 by an Ocean Optics 2000 spectrophotometer. In this work, a clear dependence of the reflectance, dominant wavelength and color purity was found in terms of the applied pressure to the AlN films. A reduction in reflectance of about 55% when the pressure was increased from 3 mtorr to 11 mtorr was observed. This paper deals with the formation of AlN thin films as promising materials for the integration of SAW devices on Si substrates due to their good piezoelectric properties and the possibility of deposition at low temperature compatible with the manufacturing of Si integrated circuits.

  2. Single-pulse CARS spectra in solid propellant combustion at atmosphere pressure

    Institute of Scientific and Technical Information of China (English)

    Zhiyun Hu(胡志云); Jingru Liu(刘晶儒); Zhenrong Zhang(张振荣); Xiaowei Guan(关小伟); Meisheng Huang(黄梅生); Xisheng Ye(叶锡生)

    2003-01-01

    The unstable-resonator spatially enhanced detection (USED) coherent anti-stokes Raman spectroscopy (CARS) measurements of temperature and N2 concentration in the combustion of solid propellant at atmosphere pressure are reported. The USED CARS measurement system has a high spatial solution of ~ 0.1 mm in diameter and 3 mm in length, and permits instantaneous measurement at 10-Hz rate. The single-pulse N2 Q-branch CARS spectra have been obtained from the propellant combustion. The temperatures and N2 concentrations of the propellant flame at different height have been achieved by fitting the experimental data to theoretical spectra. The results indicate that the temperature is up to~2500 K with N2 concentration in a range from 10% to 26%.

  3. Enhanced radiation pressure-assisted acceleration by temporally tuned counter-propagating pulses

    Energy Technology Data Exchange (ETDEWEB)

    Aurand, B., E-mail: bastian.aurand@fysik.lth.se [Department of Physics, Lund University, 22100 Lund (Sweden); Gesellschaft für Schwerionenforschung, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Kuschel, S.; Jäckel, O.; Rödel, C. [Helmholtz Institute Jena, 07743 Jena (Germany); Zhao, H.Y. [Institute of Modern Physics, 73000 Lanzhou (China); Herzer, S. [Helmholtz Institute Jena, 07743 Jena (Germany); Institute of Optics and Quantum Electronics, 07743 Jena (Germany); Paz, A.E.; Bierbach, J. [Helmholtz Institute Jena, 07743 Jena (Germany); Polz, J. [Helmholtz Institute Jena, 07743 Jena (Germany); Institute of Optics and Quantum Electronics, 07743 Jena (Germany); Elkin, B. [Fraunhofer Institut für Grenzflächen-und Bioverfahrenstechnik, 70569 Stuttgart (Germany); Karmakar, A. [Leibniz-Supercomputing Center, 85748 Garching (Germany); Gibbon, P. [ExtreMe Matter Institut, 64291 Darmstadt (Germany); Institute for Advanced Simulation, Forschungszentrum Jülich GmbH, 52428 Jülich (Germany); Kaluza, M.C. [Helmholtz Institute Jena, 07743 Jena (Germany); Institute of Optics and Quantum Electronics, 07743 Jena (Germany); Kuehl, T. [Gesellschaft für Schwerionenforschung, 64291 Darmstadt (Germany); Helmholtz Institute Jena, 07743 Jena (Germany); Universität Mainz, 55099 Mainz (Germany)

    2014-03-11

    Within the last decade, laser-ion acceleration has become a field of broad interest. The possibility to generate short proton- or heavy ion bunches with an energy of a few tens of MeV by table-top laser systems could open new opportunities for medical or technical applications. Nevertheless, today's laser-acceleration schemes lead mainly to a temperature-like energy distribution of the accelerated ions, a big disadvantage compared to mono-energetic beams from conventional accelerators. Recent results [1] of laser-ion acceleration using radiation-pressure appear promising to overcome this drawback. In this paper, we demonstrate the influence of a second counter-propagating laser pulse interacting with a nm-thick target, creating a well defined pre-plasma.

  4. Toward Ubiquitous Blood Pressure Monitoring via Pulse Transit Time: Theory and Practice.

    Science.gov (United States)

    Mukkamala, Ramakrishna; Hahn, Jin-Oh; Inan, Omer T; Mestha, Lalit K; Kim, Chang-Sei; Töreyin, Hakan; Kyal, Survi

    2015-08-01

    Ubiquitous blood pressure (BP) monitoring is needed to improve hypertension detection and control and is becoming feasible due to recent technological advances such as in wearable sensing. Pulse transit time (PTT) represents a well-known potential approach for ubiquitous BP monitoring. The goal of this review is to facilitate the achievement of reliable ubiquitous BP monitoring via PTT. We explain the conventional BP measurement methods and their limitations; present models to summarize the theory of the PTT-BP relationship; outline the approach while pinpointing the key challenges; overview the previous work toward putting the theory to practice; make suggestions for best practice and future research; and discuss realistic expectations for the approach.

  5. Nanosecond Repetitively Pulsed Discharges in Air at Atmospheric Pressure -- Experiment and Theory of Regime Transitions

    Science.gov (United States)

    Pai, David; Lacoste, Deanna; Laux, Christophe

    2009-10-01

    In atmospheric pressure air preheated from 300 to 1000 K, the Nanosecond Repetitively Pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and inter-electrode gap distance) of each discharge regime. Notably, there is a minimum gap distance for the existence of the glow regime that increases with decreasing gas temperature. A theory is developed to describe the Corona-to-Glow (C-G) and Glow-to-Spark (G-S) transitions for NRP discharges. The C-G transition is shown to depend on the Avalanche-to-Streamer Transition (AST) as well as the electric field strength in the positive column. The G-S transition is due to the thermal ionization instability. The minimum gap distance for the existence of the glow regime can be understood by considering that the applied voltage of the AST must be lower than that of the thermal ionization instability. This is a previously unknown criterion for generating glow discharges, as it does not correspond to the Paschen minimum or to the Meek-Raether criterion.

  6. Aging Characteristics on Epoxy Resin Surface Under Repetitive Microsecond Pulses in Air at Atmospheric Pressure

    Science.gov (United States)

    Xie, Qing; Liu, Xiong; Zhang, Cheng; Wang, Ruixue; Rao, Zhangquan; Shao, Tao

    2016-03-01

    Research on aging characteristics of epoxy resin (EP) under repetitive microsecond pulses is important for the design of insulating materials in high power apparatus. It is because that very fast transient overvoltage always occurs in a power system, which causes flashover and is one of the main factors causing aging effects of EP materials. Therefore, it is essential to obtain a better understanding of the aging effect on an EP surface resulting from flashover. In this work, aging effects on an EP surface were investigated by surface flashover discharge under repetitive microsecond pulses in atmospheric pressure. The investigations of parameters such as the surface micro-morphology and chemical composition of the insulation material under different degrees of aging were conducted with the aid of measurement methods such as atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Results showed that with the accumulation of aging energy on the material surface, the particles formed on the material surface increased both in number and size, leading to the growth of surface roughness and a reduction in the water contact angle; the surface also became more absorbent. Furthermore, in the aging process, the molecular chains of EP on the surface were broken, resulting in oxidation and carbonisation. supported by the Natural Science Foundation of Hebei Province (No. E2015502081), National Natural Science Foundation of China (Nos. 51222701, 51307060), and the National Basic Research Program of China (No. 2014CB239505-3)

  7. Towards radiation pressure acceleration of protons using linearly polarized ultrashort petawatt laser pulses

    CERN Document Server

    Kim, I Jong; Kim, Chul Min; Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Yu, Tae Jun; Choi, Il Woo; Lee, Chang-Lyoul; Nam, Kee Hwan; Nickles, Peter V; Jeong, Tae Moon; Lee, Jongmin

    2013-01-01

    Particle acceleration using ultraintense, ultrashort laser pulses is one of the most attractive topics in relativistic laser-plasma research. We report proton/ion acceleration in the intensity range of 5x1019 W/cm2 to 3.3x1020 W/cm2 by irradiating linearly polarized, 30-fs, 1-PW laser pulses on 10- to 100-nm-thick polymer targets. The proton energy scaling with respect to the intensity and target thickness was examined. The experiments demonstrated, for the first time with linearly polarized light, a transition from the target normal sheath acceleration to radiation pressure acceleration and showed a maximum proton energy of 45 MeV when a 10-nm-thick target was irradiated by a laser intensity of 3.3x1020 W/cm2. The experimental results were further supported by two- and three-dimensional particle-in-cell simulations. Based on the deduced proton energy scaling, proton beams having an energy of ~ 200 MeV should be feasible at a laser intensity of 1.5x1021 W/cm2.

  8. Development of a functional relationship between port pressures and flow properties for the calibration and application of multihole probes to highly three-dimensional flows

    Energy Technology Data Exchange (ETDEWEB)

    Pisasale, A.J.; Ahmed, N.A. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, 2052, Sydney (Australia)

    2004-03-01

    It is common in the calibration of multihole probes to curve-fit the calibration data in order to determine a relationship between measured port pressures and flow properties. The parameters used in these techniques typically lack a theoretical background. In this article, a functional relationship is developed, based on theoretical considerations, that relates the port pressure directly to the flow properties and details a procedure that enables flow properties to be determined from the measured pressures of the multihole probe. The method is simple, easy to implement and provides a better understanding of the multihole probe operation in a three-dimensional flow. (orig.)

  9. Pulse pressure variation and prediction of fluid responsiveness in patients ventilated with low tidal volumes

    Directory of Open Access Journals (Sweden)

    Clarice Daniele Alves de Oliveira-Costa

    2012-07-01

    Full Text Available OBJECTIVE: To determine the utility of pulse pressure variation (ΔRESP PP in predicting fluid responsiveness in patients ventilated with low tidal volumes (V T and to investigate whether a lower ΔRESP PP cut-off value should be used when patients are ventilated with low tidal volumes. METHOD: This cross-sectional observational study included 37 critically ill patients with acute circulatory failure who required fluid challenge. The patients were sedated and mechanically ventilated with a V T of 6-7 ml/kg ideal body weight, which was monitored with a pulmonary artery catheter and an arterial line. The mechanical ventilation and hemodynamic parameters, including ΔRESP PP, were measured before and after fluid challenge with 1,000 ml crystalloids or 500 ml colloids. Fluid responsiveness was defined as an increase in the cardiac index of at least 15%. ClinicalTrial.gov: NCT01569308. RESULTS: A total of 17 patients were classified as responders. Analysis of the area under the ROC curve (AUC showed that the optimal cut-off point for ΔRESP PP to predict fluid responsiveness was 10% (AUC = 0.74. Adjustment of the ΔRESP PP to account for driving pressure did not improve the accuracy (AUC = 0.76. A ΔRESP PP>10% was a better predictor of fluid responsiveness than central venous pressure (AUC = 0.57 or pulmonary wedge pressure (AUC = 051. Of the 37 patients, 25 were in septic shock. The AUC for ΔRESP PP>10% to predict responsiveness in patients with septic shock was 0.484 (sensitivity, 78%; specificity, 93%. CONCLUSION: The parameter D RESP PP has limited value in predicting fluid responsiveness in patients who are ventilated with low tidal volumes, but a ΔRESP PP>10% is a significant improvement over static parameters. A ΔRESP PP > 10% may be particularly useful for identifying responders in patients with septic shock.

  10. Pulse pressure variation and stroke volume variation under different inhaled concentrations of isoflurane, sevoflurane and desflurane in pigs undergoing hemorrhage

    Directory of Open Access Journals (Sweden)

    Alexandre Hideaki Oshiro

    2015-12-01

    Full Text Available OBJECTIVES: Inhalant anesthesia induces dose-dependent cardiovascular depression, but whether fluid responsiveness is differentially influenced by the inhalant agent and plasma volemia remains unknown. The aim of this study was to compare the effects of isoflurane, sevoflurane and desflurane on pulse pressure variation and stroke volume variation in pigs undergoing hemorrhage. METHODS: Twenty-five pigs were randomly anesthetized with isoflurane, sevoflurane or desflurane. Hemodynamic and echocardiographic data were registered sequentially at minimum alveolar concentrations of 1.00 (M1, 1.25 (M2, and 1.00 (M3. Then, following withdrawal of 30% of the estimated blood volume, these data were registered at a minimum alveolar concentrations of 1.00 (M4 and 1.25 (M5. RESULTS: The minimum alveolar concentration increase from 1.00 to 1.25 (M2 decreased the cardiac index and increased the central venous pressure, but only modest changes in mean arterial pressure, pulse pressure variation and stroke volume variation were observed in all groups from M1 to M2. A significant decrease in mean arterial pressure was only observed with desflurane. Following blood loss (M4, pulse pressure variation, stroke volume variation and central venous pressure increased (p <0.001 and mean arterial pressure decreased in all groups. Under hypovolemia, the cardiac index decreased with the increase of anesthesia depth in a similar manner in all groups. CONCLUSION: The effects of desflurane, sevoflurane and isoflurane on pulse pressure variation and stroke volume variation were not different during normovolemia or hypovolemia.

  11. Pulse wave myelopathy: An update of an hypothesis highlighting the similarities between syringomyelia and normal pressure hydrocephalus.

    Science.gov (United States)

    Bateman, Grant A

    2015-12-01

    Most hypotheses trying to explain the pathophysiology of idiopathic syringomyelia involve mechanisms whereby CSF is pumped against a pressure gradient, from the subarachnoid space into the cord parenchyma. On review, these theories have universally failed to explain the disease process. A few papers have suggested that the syrinx fluid may originate from the cord capillary bed itself. However, in these papers, the fluid is said to accumulate due to impaired fluid drainage out of the cord. Again, there is little evidence to substantiate this. This proffered hypothesis looks at the problem from the perspective that syringomyelia and normal pressure hydrocephalus are almost identical in their manifestations but only differ in their site of effect within the neuraxis. It is suggested that the primary trigger for syringomyelia is a reduction in the compliance of the veins draining the spinal cord. This reduces the efficiency of the pulse wave dampening, occurring within the cord parenchyma, increasing arteriolar and capillary pulse pressure. The increased capillary pulse pressure opens the blood-spinal cord barrier due to a direct effect upon the wall integrity and interstitial fluid accumulates due to an increased secretion rate. An increase in arteriolar pulse pressure increases the kinetic energy within the cord parenchyma and this disrupts the cytoarchitecture allowing the fluid to accumulate into small cystic regions in the cord. With time the cystic regions coalesce to form one large cavity which continues to increase in size due to the ongoing interstitial fluid secretion and the hyperdynamic cord vasculature.

  12. STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi [SIGMA Weather Group, State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Xie, Yanqiong [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing (China); Xu, Xiaojun, E-mail: pbzuo@spaceweather.ac.cn, E-mail: fengx@spaceweather.ac.cn [Space Science Institute, Macau University of Science and Technology, Macao (China)

    2015-10-20

    In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector.

  13. Association of Pulse Pressure with Serum TNF-α and Neutrophil Count in the Elderly

    Directory of Open Access Journals (Sweden)

    Eriko Yamada

    2014-01-01

    Full Text Available Aims. Elevated pulse pressure (PP has been reported to be a risk factor for type 2 diabetes in elderly patients with hypertension. Methods. Cross-sectional relationships of PP with known risk factors for type 2 diabetes and inflammatory markers were examined in 150 elderly community-dwelling women, 79 women (52.7% of whom had hypertension. Results. Systolic blood pressure (standardized β, 0.775, log tumor necrosis factor-α (TNF-α, standardized β, 0.110, age (standardized β, 0.140, and neutrophil count (standardized β, 0.114 emerged as determinants of PP independent of high-sensitivity C-reactive protein, interleukin-6, monocyte count, plasminogen activator inhibitor-1, homeostasis model assessment of insulin resistance, HDL-cholesterol, and adiponectin (R2 = 0.772. Conclusions. The present studies have demonstrated an independent association of higher PP with higher TNF-α, a marker of insulin resistance, and neutrophil count in community-living elderly women and suggest that insulin resistance and chronic low-grade inflammation may in part be responsible for the association between high PP and incident type 2 diabetes found in elderly patients with hypertension.

  14. 新型自检脉搏传感器的研制%New type pulse transducer of self-calibration

    Institute of Scientific and Technical Information of China (English)

    张东青; 王元昔

    2001-01-01

    The new type self-calibration pulse transducer will transform the pulse of human body to the electric signal for the measurement and analyse.It will make an objective distinguish standard for the traditional Chinese medical science to reveal the modern scientific substance of diagnose pulse. This essay will introduce the design, technique and working principle of the pulse transducer and analyse for the result of measurement.%新型自检脉搏传感器是将人体脉搏波转化为电信号进行测量和分析,它对中医的脉象有了一个客观的分辨标准,便于揭开脉诊现代科学本质。介绍新型自检脉搏传感器的设计及工艺,阐述了该传感器的工作原理,最后对测试的结果进行分析。

  15. Effect of Inflammation on the Relationship of Pulse Pressure and Mortality in Haemodialysis

    Directory of Open Access Journals (Sweden)

    Debasish Banerjee

    2012-01-01

    Full Text Available Background/Aim: The effect of hypertension on mortality in haemodialysis patients is controversial and can be confounded by non-traditional risk factors like systemic inflammation. This study examined the effect of systolic blood pressure (SBP, diastolic blood pressure (DBP, and pulse pressure (PP on mortality in haemodialysis patients, separately with and without markers of systemic inflammation. Methods:Data from the United States Renal Data System were analysed for 9,862 patients receiving haemodialysis on December 31, 1993, followed through May 2005. Results: In Cox regression analysis, increased age, diabetes, low albumin, high white blood count, low cholesterol, low haemoglobin, high phosphate, low DBP, and cardiovascular comorbidity were associated with high mortality, but SBP was not. Elevated PP adjusted for SBP, age, diabetes, haemoglobin, albumin, cholesterol, calcium, phosphate, parathyroid hormone, and white blood count was associated with higher mortality [adjusted hazard ratio, PP 1.006 (95% confidence interval, CI, 1.002–1.010; SBP 0.993 (95% CI 0.990–0.996]. In dual models, PP adjusted for SBP then DBP was associated with higher mortality [PP 1.029 (95% CI 1.027–1.032; SBP 0.981 (95% CI 0.979–0.983; PP 1.010 (95% CI 1.008–1.011; DBP 0.981 (95% CI 0.979–0.983]. Increasing PP deciles >70 mm Hg were associated with increasing mortality in the absence of markers of systemic inflammation (white blood count >10 × 109/l, albumin Conclusion: PP was a better indicator of adverse outcome than DBP or SBP. Inflammation-associated injury may mask the effect of PP on mortality in haemodialysis patients.

  16. Pulsed electron beam propagation in gases under pressure of 6.6 kPa in drift tube

    Science.gov (United States)

    Kholodnaya, G. E.; Sazonov, R. V.; Ponomarev, D. V.; Remnev, G. E.; Poloskov, A. V.

    2017-02-01

    This paper presents the results of an investigation of pulsed electron beam transport propagated in a drift tube filled with different gases (He, H2, N2, Ar, SF6, and CO2). The total pressure in the drift tube was 6.6 kPa. The experiments were carried out using a TEA-500 pulsed electron accelerator. The electron beam was propagated in the drift tube composed of two sections equipped with reverse current shunts. Under a pressure of 6.6 kPa, the maximum value of the electron beam charge closed on the walls of the drift tube was recorded when the beam was propagated in hydrogen and carbon dioxide. The minimum value of the electron beam charge closed on the walls of the drift tube was recorded for sulfur hexafluoride. The visualization of the pulsed electron beam energy losses onto the walls of the drift chamber was carried out using radiation-sensitive film.

  17. Plasma-chemical reactor based on a low-pressure pulsed arc discharge for synthesis of nanopowders

    Science.gov (United States)

    Karpov, I. V.; Ushakov, A. V.; Lepeshev, A. A.; Fedorov, L. Yu.

    2017-01-01

    A reactor for producing nanopowders in the plasma of a low-pressure arc discharge has been developed. As a plasma source, a pulsed cold-cathode arc evaporator has been applied. The design and operating principle of the reactor have been described. Experimental data on how the movement of a gaseous mixture in the reactor influences the properties of nanopowders have been presented.

  18. Real-time digital signal processor implementation of self-calibrating pulse-shape discriminator for high purity germanium

    CERN Document Server

    Suarez, R; Aalseth, C E; Hossbach, T W; Miley, H S

    2007-01-01

    Pulse-shape analysis of the ionization signals from germanium gamma-ray spectrometers is a method for obtaining information that can characterize an event beyond just the total energy deposited in the crystal. However, as typically employed, this method is data-intensive requiring the digitization, transfer, and recording of electronic signals from the spectrometer. A hardware realization of a real-time digital signal processor for implementing a parametric pulse shape is presented. Specifically, a previously developed method for distinguishing between single-site and multi-site gamma-ray interactions is demonstrated in an on-line digital signal processor, compared with the original off-line pulse-shape analysis routine, and shown to have no significant difference. Reduction of the amount of the recorded information per event is shown to translate into higher duty-cycle data acquisition rates while retaining the benefits of additional event characterization from pulse-shape analysis.

  19. Pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus ® for the perioperative management of a caesarean section in a patient with severe cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Nicolas Brogly

    2016-06-01

    Full Text Available ABSTRACT BACKGROUND: The delivery of cardiac patients is a challenge for the anaesthesiologist, to whom the welfare of both the mother and the foetus is a main issue. In case of caesarean section, advanced monitoring allows to optimize haemodynamic condition and to improve morbidity and mortality. OBJECTIVE: To describe the use of pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus® for the perioperative management of a caesarean section in a patient with severe cardiomyopathy. CASE REPORT: We describe the case of a 28-year-old woman with a congenital heart disease who was submitted to a caesarean section under general anaesthesia for maternal pathology and foetal breech presentation. Intra- and post-operative management was optimized by advanced haemodynamic monitorization obtained by pulse contour wave analysis and thermodilution calibration (Picco Plus® monitor. The information about preload, myocardial contractility and postcharge was useful in guiding the fluid therapy and the use of vasoactive drugs. CONCLUSION: This case report illustrates the importance of advanced haemodynamic monitoring with an acceptably invasive device in obstetric patients with high cardiac risk. The increasing experience in advanced haemodynamic management will probably permit to decrease morbidity and mortality of obstetric patients in the future.

  20. Monounsaturated fatty acid, carbohydrate intake, and diabetes status are associated with arterial pulse pressure

    Directory of Open Access Journals (Sweden)

    Vaccaro Joan A

    2011-11-01

    Full Text Available Abstract Background Diabetes is a global epidemic. Cardiovascular disease (CVD is one of the most prevalent consequences of diabetes. Nutrition is considered a modifiable risk factor for CVD, particularly for individuals with diabetes; albeit, there is little consensus on the role of carbohydrates, proteins and fats for arterial health for persons with or without diabetes. In this study, we examined the association of macronutrients with arterial pulse pressure (APP, a surrogate measure of arterial health by diabetes status and race. Methods Participants were 892 Mexican Americans (MA, 1059 Black, non-Hispanics (BNH and 2473 White, non-Hispanics (WNH with and without diabetes of a weighted sample from the National Nutrition and Health Examination Survey (NHANES 2007-2008. The cross-sectional analysis was performed with IBM-SPSS version 18 with the complex sample analysis module. The two-year sample weight for the sub-sample with laboratory values was applied to reduce bias and approximate a nationally, representative sample. Arterial stiffness was assessed by arterial pulse pressure (APP. Results APP was higher for MA [B = 0.063 (95% CI 0.015 to 0.111, p = 0.013] and BNH [B = 0.044 (95% CI 0.006 to 0.082, p = 0.018] than WNH, controlling for diabetes, age, gender, body mass index (BMI, fiber intake, energy intake (Kcal and smoking. A two-way interaction of diabetes by carbohydrate intake (grams was inversely associated with APP [B = -1.18 (95% CI -0.178 to -0.058, p = 0.001], controlling for race, age, gender, BMI, Kcal and smoking. BNH with diabetes who consumed more mono-unsaturated fatty acids (MUFA than WNH with diabetes had lower APP [B = -0.112 (95%CI-0.179 to -0.045, p = 0.003] adjusting for saturated fatty acids, Kcal, age, gender, BMI and smoking. Conclusion Higher MUFA and carbohydrate intake for persons with diabetes reflecting lower APP may be due to replacement of saturated fats with CHO and MUFA. The associations of APP with

  1. Dependence of the absorption of pulsed CO2-laser radiation by silane on wavenumber, fluence, pulse duration, temperature, optical path length, and pressure of absorbing and nonabsorbing gases

    Science.gov (United States)

    Bl/aŻejowski, Jerzy; Gruzdiewa, Ludwika; Rulewski, Jacek; Lampe, Frederick W.

    1995-05-01

    The absorption of three lines [P(20), 944.2 cm-1; P(14), 949.2 cm-1; and R(24), 978.5 cm-1] of the pulsed CO2 laser (0001-1000 transition) by SiH4 was measured at various pulse energy, pulse duration, temperature, optical path length, and pressure of the compound and nonabsorbing foreign gases. In addition, low intensity infrared absorption spectrum of silane was compared with high intensity absorption characteristics for all lines of the pulsed CO2 laser. The experimental dependencies show deviations from the phenomenological Beer-Lambert law which can be considered as arising from the high intensity of an incident radiation and collisions of absorbing molecules with surroundings. These effects were included into the expression, being an extended form of the Beer-Lambert law, which reasonably approximates all experimental data. The results, except for extending knowledge on the interaction of a high power laser radiation with matter, can help understanding and planning processes leading to preparation of silicon-containing technologically important materials.

  2. Support vector machines as multivariate calibration model for prediction of blood glucose concentration using a new non-invasive optical method named Pulse Glucometry.

    Science.gov (United States)

    Ogawa, Mitsuhiro; Yamakoshi, Yasuhiro; Satoh, Makoto; Nogawa, Masamichi; Yamakoshi, Takehiro; Tanaka, Shinobu; Rolfe, Peter; Tamura, Toshiyo; Yamakoshi, Ken-ichi

    2007-01-01

    A novel optical non-invasive in vivo blood glucose concentration (BGL) measurement technique, named "Pulse Glucometry", was combined with a kernel method; support vector machines. The total transmitted radiation intensity (I lambda) and the cardiac-related pulsatile changes superimposed on I lambda in human adult fingertips were measured over the wavelength range from 900 to 1700 nm using a very fast spectrophotometer, obtaining a differential optical density (delta OD lambda) related to the blood component in the finger tissues. Subsequently, a calibration model using paired data of a family of delta OD lambda s and the corresponding known BGLs was constructed with support vector machines regression instead of using calibration by a conventional partial least squares regression (PLS). Our results show that the calibration model based on the support vector machines can provide a good regression for the 183 paired data, in which the BGLs ranged from 89.0-219 mg/dl (4.94-12.2 mmol/l). The resultant regression was evaluated by the Clarke error grid analysis and all data points fell within the clinically acceptable regions (region A: 93%, region B: 7%).

  3. Relations between diabetes, blood pressure and aortic pulse wave velocity in haemodialysis patients

    DEFF Research Database (Denmark)

    Peters, Christian Daugaard; Kjærgaard, Krista Dybtved; Dzeko, Mirela;

    Diabetes (DM) is common in haemodialysis (HD) patients and affects both blood pressure (BP) and arterial stiffness. Carotid femoral pulse wave velocity (PWV) reflects the stiffness of the aorta and is regarded as a strong risk factor for cardiovascular (CV) mortality in HD patients. However, PWV...... is highly influenced by the BP-level. Higher PWV-values among HD patients with DM could reflect a higher BP-level rather than increased arterial stiffness. The aim of this study was to investigate the effect of DM on BP and PWV in a group of HD patients. BP and PWV were measured in 66 HD patients without DM...... (HD) and 32 HD patients with DM (HD+DM). The SphygmoCor system was used for estimation of PWV. HD-duration, age, gender and BP medication were similar in the two groups. Mean DM-duration was 23±11 years and 25(78%) had type 2 DM. HD+DM had higher BMI (26±5 vs. 29±5 kg/m2, p=0.02), systolic BP (142...

  4. Effect of Pulse Pressure Treatment on Content of Protein and Some Sugars in Wheat Seeds

    Directory of Open Access Journals (Sweden)

    Violetta Pavlova

    2013-12-01

    Full Text Available Seeds of hard wheat (Triticum durum were treated by pulse pressure (PP, generated by shock wave. Protein content was determined by spectroscopy in the nearest infrared point of the spectrum (NIR. HPLC was used for determining glucose level in samples. Moisture of control seeds was 14.2%. It was not changed in PP 11 MPa samples and was decreased by PP 29 MPa (12.8%; that indicated the damage of seeds. Protein content in control sample was 16.5%. The index was not changed by PP 11 MPa (16.9%, but it increased under PP 29 MPa (17.2% due to the degradation of starch and relative elevation of protein level. Glucose content in PP 11 MPa samples was less than the control level, probably, due to the acceleration of amino-carbonyl reaction. PP 29 MPa promoted the increase of glucose content due to non-enzymatic starch hydrolysis activation. Thus PP 11 MPa made minor damages without the accumulation of glucose, but PP 29 MPa promoted the ageing due to the accumulation of glucose.

  5. Laser-Ionization TOF Mass Spectrometer Characterization of Benzene Destruction in Atmospheric Pressure Pulsed Discharge

    Institute of Scientific and Technical Information of China (English)

    LIU Jiahong; XIAO Qingmei; WANG Liping; YAO Zhi; DING Hongbin

    2009-01-01

    Benzene is.a major industrial air pollutant and can cause serious human health disorders. In this paper an investigation on benzene destruction, in an atmospheric-pressure fast-flow pulsed DC-discharge by means of laser ionization combined with time-of-flight (TOF) mass spectrometry, is reported. Most by-products including transient reactive species from the benzene discharge were characterized by molecular beam sampling combined with TOF mass spectrometry.It is showed that, with a gas mixture of 0.5% C6H6 in Ar, benzene can be effectively destroyed by discharge plasma. The intermediate species consisted of small fragments of CNHm (n=3~5,m =1~11), cycle-chain species of CNHm (n=6~9, m = 7~10) and polycyclic species CNHm (n ≥9,m = 8~12). The alternation of mass peaks (intensity) with even/odd electrons was observed in the measured mass spectra. The results indicated that the alternation is mainly due to the different ionization potentials of the open shell and close shell species. Based on the examination of the features of the species' composition, the primary reaction pathways are proposed and discussed.

  6. Pressure and stress waves in a spallation neutron source mercury target generated by high-power proton pulses

    CERN Document Server

    Futakawa, M; Conrad, H; Stechemesser, H

    2000-01-01

    The international ASTE collaboration has performed a first series of measurements on a spallation neutron source target at the Alternating Gradient Synchrotron (AGS) in Brookhaven. The dynamic response of a liquid mercury target hit by high-power proton pulses of about 40 ns duration has been measured by a laser Doppler technique and compared with finite elements calculations using the ABAQUS code. It is shown that the calculation can describe the experimental results for at least the time interval up to 100 mu s after the pulse injection. Furthermore, it has been observed that piezoelectric pressure transducers cannot be applied in the high gamma-radiation field of a spallation target.

  7. Signal-Pressure Curves of Cascaded Four-Wave Mixing in Gas-Filled Capillary by fs Pulses

    Institute of Scientific and Technical Information of China (English)

    CHEN Bao-Zhen; HUANG Zu-Qia

    2005-01-01

    The theoretical framework for the cascaded four waves mixing (CFWM) in gas-filled capillary by fs pulses is constructed. Based on the theoretical framework, the signal-pressure curves (SPC) of the CFWM in gas-filled capillary by fs pulses are calculated. With a comparison between the theoretical and experimental SPC we have discussed the influence of the walk-off and Phase modulation on the SPC. At the same time, we have discussed the possible origin of the first three peaks of the SPC.

  8. Pulsed positive discharges in air at moderate pressures near a dielectric rod

    Science.gov (United States)

    Dubinova, A.; Trienekens, D.; Ebert, U.; Nijdam, S.; Christen, T.

    2016-10-01

    We study pulsed positive discharges in air in a cylindrically symmetric setup with an electrode needle close (about 1 mm) above the top of a dielectric cylindrical rod of 4 mm in diameter mounted at its bottom on a grounded plate electrode. We present ICCD (intensified charge-coupled device) pictures and evaluations of experiments as well as simulations with a fluid discharge model; the simulations use cylindrical symmetry. In the experiments, there is an initial inception cloud phase, where the cylindrical symmetry is maintained, and later a streamer phase, where it is broken spontaneously. At 75-150 mbar, discharges with cylindrical symmetry are not attracted to the dielectric rod, but move away from it. The dielectric rod plays the sole role of an obstacle that shades (in the context of photoionization) a cone-shaped part of the inception cloud; the cone size is determined by the geometry of the setup. The material properties of the dielectric rod, such as its dielectric permittivity and the efficiency of the photon induced secondary electron emission do not have a noticeable effect. This is due to the abundance of photoionization in air, which supplies a positive discharge with free electrons and allows it to propagate along the electric field lines. Using some simple field calculations, we show that field enhancement due to dielectric polarization does not play a significant role in our geometry as long as the discharge maintains its cylindrical symmetry. The field component towards the rod is insufficiently enhanced to cause the discharge to move towards the rod. Any additional electrons produced by the dielectric surface do not influence this discharge morphology. This interpretation is supported by both experiments and simulations. At higher pressures (400-600 mbar) or for larger gaps between the needle and the dielectric rod, the inception cloud reaches its maximal radius within the gap between needle and rod and destabilizes there. In those cases

  9. Calibrated versus uncalibrated arterial pressure waveform analysis in monitoring cardiac output with transpulmonary thermodilution in patients with severe sepsis and septic shock: an observational study

    NARCIS (Netherlands)

    Slagt, C.; Helmi, M.; Malagon, I.; Groeneveld, A.B.

    2015-01-01

    BACKGROUND: Cardiac output (CO) measurement is often required in critically ill patients. The performances of newer, less invasive techniques require evaluation in patients with severe sepsis and septic shock. OBJECTIVES: To compare calibrated arterial pressure waveform analysis-derived CO (COap, Vo

  10. Amine-containing film deposited in pulsed dielectric barrier discharge at a high pressure and its cell adsorption behaviours

    Institute of Scientific and Technical Information of China (English)

    Hu Wen-Juan; Xie Fen-Yan; Chen Qiang; Weng Jing

    2009-01-01

    With monomer allylamine, amine-containing functional films were prepared in alternative current pulsed dielectric barrier discharge (DBD) at a high pressure. This paper analyses in detail the film properties and structures, such as hydrophilicity, compounds and microstructures as well as amine density by the water contact angle, Fourier transform infrared spectroscopy, atomic force microscopy, and ultraviolet-visible measurement. The influence of discharge param-eters, in particular applied power, on amine density was investigated. As an application the cell adsorption behaviours on plasma polymerization films was performed in-vitro. The results show that at a high pressure pulsed DBD plasma can polymerize films with sufficient amine group on surface, through which the very efficient cell adsorption behaviours was demonstrated, and the high rate of cell proliferation was visualized.

  11. Calibration of nylon organic chemical integrative samplers and sentinel samplers for quantitative measurement of pulsed aquatic exposures.

    Science.gov (United States)

    Morrison, Shane A; Belden, Jason B

    2016-06-03

    Environmental exposures often occur through short, pulsed events; therefore, the ability to accurately measure these toxicologically-relevant concentrations is important. Three different integrative passive sampler configurations were evaluated under different flow and pulsed exposure conditions for the measurement of current-use pesticides (n=19), polyaromatic hydrocarbons (n=10), and personal care products (n=5) spanning a broad range of hydrophobicities (log Kow 1.5-7.6). Two modified POCIS-style samplers were investigated using macroporous nylon mesh membranes (35μm pores) and two different sorbent materials (i.e. Oasis HLB and Dowex Optipore L-493). A recently developed design, the Sentinel Sampler (ABS Materials), utilizing Osorb media enclosed within stainless steel mesh (145μm pores), was also investigated. Relatively high sampling rates (Rs) were achieved for all sampler configurations during the short eight-day exposure (4300-27mL/d). Under flow conditions, median Rs were approximately 5-10 times higher for POCIS-style samplers and 27 times higher for Sentinel Samplers, as compared to static conditions. The ability of samplers to rapidly measure hydrophobic contaminants may be a trade off with increased flow dependence. Analyte accumulation was integrative under pulsed and continuous exposures for POCIS-style samplers with mean difference between treatments of 11% and 33%; however, accumulation into Sentinel Samplers was more variable. Collectively, results show that reducing membrane limitations allows for rapid, integrative accumulation of a broad range of analytes even under pulsed exposures. As such, these sampler designs may be suitable for monitoring environmental substances that have short aquatic half-lives.

  12. Effects of non-thermal atmospheric pressure pulsed plasma on the adhesion and durability of resin composite to dentin.

    Science.gov (United States)

    Han, Geum-Jun; Kim, Jae-Hoon; Chung, Sung-No; Chun, Bae-Hyeock; Kim, Chang-Keun; Seo, Deog-Gyu; Son, Ho-Hyun; Cho, Byeong-Hoon

    2014-12-01

    This study investigated the effect of low-power, non-thermal atmospheric pressure plasma (NT-APP) treatments, in pulsed and conventional modes, on the adhesion of resin composite to dentin and on the durability of the bond between resin composite and dentin. A pencil-type NT-APP jet was applied in pulsed and conventional modes to acid-etched dentin. The microtensile bond strength (MTBS) of resin composite to dentin was evaluated at 24 h and after thermocycling in one control group (no plasma) and in two experimental groups (pulsed plasma and conventional plasma groups) using the Scotchbond Multi-Purpose Plus Adhesive System. Data were analyzed using two-factor repeated-measures anova and Weibull statistics. Fractured surfaces and the bonded interfaces were evaluated using a field-emission scanning electron microscope. Although there were no significant differences between the plasma treatment groups, the plasma treatment improved the MTBS compared with the control group. After thermocycling, the MTBS did not decrease in the control or conventional plasma group but increased in the pulsed plasma group. Thermocycling increased the Weibull moduli of plasma-treated groups. In conclusion, plasma treatment using NT-APP improved the adhesion of resin composite to dentin. Using a pulsed energy source, the energy delivered to the dentin was effectively reduced without any reduction in bond strength or durability.

  13. Improved operation of a microwave pulse compressor with a laser-triggered high-pressure gas plasma switch

    Science.gov (United States)

    Shlapakovski, A.; Gorev, S.; Krasik, Ya. E.

    2016-08-01

    The influence of laser beam parameters on the output pulses of a resonant microwave compressor with a laser-triggered plasma switch was investigated. The S-band compressor, consisting of a rectangular waveguide-based cavity and H-plane waveguide tee with a shorted side arm, was filled with pressurized dry air and pumped by 1.8-μs-long microwave pulses of up to 450 kW power. A Nd:YAG laser was used to ignite the gas discharge in the tee side arm for output pulse extraction. The laser beam (at 213 nm or 532 nm) was directed along the RF electric field lines. It was found that the compressor operated most effectively when the laser beam was focused at the center of the switch waveguide cross-section. In this case, the power extraction efficiency reached ˜47% at an output power of ˜14 MW, while when the laser beam was not focused the maximal extraction efficiency was only ˜20% at ˜6 MW output power. Focusing the laser beam resulted also in a dramatic decrease (down to switch, and the jitter of the output pulses' appearance was minimized. In addition, the quality of the output pulses' waveform was significantly improved.

  14. In-situ calibration of pulsed eddy current detection of cracks at fasteners in CP-140 aircraft

    Science.gov (United States)

    Underhill, Ross; Stott, Colette; Krause, Thomas W.

    2016-02-01

    The use of the Smallest Half Volume (SHV) robust statistics method and the Mahalanobis distance to blindly distinguish fasteners with cracks from fasteners without is examined. Pulsed eddy current data obtained from CP140 Aurora wing structures is used to test the approach. It is shown that the method can achieve levels of detection very close to those obtained when the same measurement technique is applied with full knowledge of which fasteners have no cracks. The method is applicable to a broad range of similar situations when an objective hit/miss criterion is used.

  15. Correlation of pulse wave velocity with left ventricular mass in patients with hypertension once blood pressure has been normalized

    Directory of Open Access Journals (Sweden)

    Siu H. Chan

    2012-02-01

    Full Text Available Vascular stiffness has been proposed as a simple method to assess arterial loading conditions of the heart which induce left ventricular hypertrophy (LVH. There is some controversy as to whether the relationship of vascular stiffness to LVH is independent of blood pressure, and which measurement of arterial stiffness, augmentation index (AI or pulse wave velocity (PWV is best. Carotid pulse wave contor and pulse wave velocity of patients (n=20 with hypertension whose blood pressure (BP was under control (<140/90 mmHg with antihypertensive drug treatment medications, and without valvular heart disease, were measured. Left ventricular mass, calculated from 2D echocardiogram, was adjusted for body size using two different methods: body surface area and height. There was a significant (P<0.05 linear correlation between LV mass index and pulse wave velocity. This was not explained by BP level or lower LV mass in women, as there was no significant difference in PWV according to gender (1140.1+67.8 vs 1110.6+57.7 cm/s. In contrast to PWV, there was no significant correlation between LV mass and AI. In summary, these data suggest that aortic vascular stiffness is an indicator of LV mass even when blood pressure is controlled to less than 140/90 mmHg in hypertensive patients. The data further suggest that PWV is a better proxy or surrogate marker for LV mass than AI and the measurement of PWV may be useful as a rapid and less expensive assessment of the presence of LVH in this patient population.

  16. Intraocular pressure and ocular pulse amplitude using dynamic contour tonometry and contact lens tonometry

    Directory of Open Access Journals (Sweden)

    Grus Franz-H

    2004-03-01

    Full Text Available Abstract Background The new Ocular Dynamic Contour Tonometer (DCT, investigational device supplied by SMT (Swiss Microtechnology AG, Switzerland allows simultaneous recording of intraocular pressure (IOP and ocular pulse amplitude (OPA. It was the aim of this study to compare the IOP results of this new device with Goldmann tonometry. Furthermore, IOP and OPA measured with the new slitlamp-mounted DCT were compared to the IOP and OPA measured with the hand-held SmartLens®, a gonioscopic contact lens tonometer (ODC Ophthalmic Development Company AG, Switzerland. Methods Nineteen healthy subjects were included in this study. IOP was determined by three consecutive measurements with each of the DCT, SmartLens®, and Goldmann tonometer. Furthermore, OPA was measured three times consecutively by DCT and SmartLens®. Results No difference (P = 0.09 was found between the IOP values by means of DCT (mean: 16.6 mm Hg, median: 15.33 mm Hg, SD: +/- 4.04 mm Hg and Goldmann tonometry (mean: 16.17 mm Hg, median: 15.33 mm Hg, SD: +/- 4.03 mm Hg. The IOP values of SmartLens® (mean: 20.25 mm Hg, median: 19.00 mm Hg, SD: +/- 4.96 mm Hg were significantly higher (P = 0.0008 both from Goldmann tonometry and DCT. The OPA values of the DCT (mean: 3.08 mm Hg, SD: +/- 0.92 mm Hg were significantly lower (P = 0.0003 than those obtained by SmartLens® (mean: 3.92 mm Hg, SD: +/- 0.83 mm Hg. Conclusions DCT was equivalent to Goldmann applanation tonometry in measurement of IOP in a small group of normal subjects. In contrast, SmartLens® (contact lens tonometry gave IOP readings that were significantly higher compared with Goldmann applanation tonometer readings. Both devices, DCT and SmartLens® provide the measurement of OPA which could be helpful e.g. for the management of glaucoma.

  17. Preparation of TiO sub 2 nanoparticles by pulsed laser ablation: Ambient pressure dependence of crystallization

    CERN Document Server

    Matsubara, M; Yamaki, T; Itoh, H; Abe, H

    2003-01-01

    Pulsed laser ablation (PLA) with a KrF excimer laser was used to prepare fine particles of titanium dioxide (TiO sub 2). The ablation in an atmosphere of Ar and O sub 2 (5:5) at total pressures of >= 1 Torr led to the formation of TiO sub 2 nanoparticles composed of anatase and rutile structures without any suboxides. The weight fraction of the rutile/anatase crystalline phases was dependent on the pressure of the Ar/O sub 2 gas. The TiO sub 2 nanoparticles had a spherical shape and their size, ranging from 10 and 14 nm, also appeared to be dependent on the ambient pressure. (author)

  18. Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

    Directory of Open Access Journals (Sweden)

    Randa Aly Soliman

    2015-04-01

    Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

  19. Impact of low-pressure glow-discharge-pulsed plasma polymerization on properties of polyaniline thin films

    Science.gov (United States)

    Jatratkar, Aviraj A.; Yadav, Jyotiprakash B.; Deshmukh, R. R.; Barshilia, Harish C.; Puri, Vijaya; Puri, R. K.

    2016-12-01

    This study reports on polyaniline thin films deposited on a glass substrate using a low-pressure glow-discharge-pulsed plasma polymerization method. The polyaniline thin film obtained by pulsed plasma polymerization has been successfully demonstrated as an optical waveguide with a transmission loss of 3.93 dB cm-1, and has the potential to be employed in integrated optics. An attempt has been made to investigate the effect of plasma OFF-time on the structural, optical as well as surface properties of polyaniline thin film. The plasma ON-time has been kept constant and the plasma OFF-time has been varied throughout the work. The plasma OFF-time strongly influenced the properties of the polyaniline thin film, and a nanostructured and compact surface was revealed in the morphological studies. The plasma OFF-time was found to enhance film thickness, roughness, refractive index and optical transmission loss, whereas it reduced the optical band gap of the polyaniline thin films. Retention in the aromatic structure was confirmed by FTIR results. Optical studies revealed a π-π* electronic transition at about 317 nm as well as the formation of a branched structure. As compared with continuous wave plasma, pulsed plasma polymerization shows better properties. Pulsed plasma polymerization reduced the roughness of the film from 1.2 nm to 0.42 nm and the optical transmission loss from 6.56 dB cm-1 to 3.39 dB cm-1.

  20. Experimental study of propagation characteristics of a pulse-modulated surface-wave argon plasma at atmospheric pressure

    Science.gov (United States)

    Chen, Chuan-Jie; Li, Shou-Zhe; Wu, Yue; Li, Zhen-Ye; Zhang, Jialiang; Wang, Yong-Xing

    2016-12-01

    An atmospheric-pressure, pulse-modulated surface wave argon plasma is investigated with respect to its propagation of the ionization front. The time-resolved photographs about the advance of the ionization front are taken using a high speed camera. The ionization front velocity and its rise time when propagating along the discharge tube are measured with respect to a series of values of input power, duty ratio, and the pulse repetition frequency. The interpretations are given on the basis of the ionization and diffusion processes. And it is also found that the reduced electric field and memory effect from previous discharge impose the influence on both the ionization front velocity and its rise time strongly.

  1. Pulse pressure and heart rate in patients with metabolic syndrome across Europe: insights from the GOOD survey.

    Science.gov (United States)

    Perlini, S; Naditch-Brule, L; Farsang, C; Zidek, W; Kjeldsen, S E

    2013-07-01

    The Global Cardiometabolic Risk Profile in Patients with hypertension disease (GOOD) survey investigated the global cardiometabolic risk profile in 3464 adult outpatients with hypertension across 289 sites in 12 European countries. The pulse pressure and heart rate profile of the survey population was evaluated according to the presence or absence of metabolic syndrome and/or type 2 diabetes mellitus. History and treatment of hypertension were not counted as criteria for metabolic syndrome as they applied to all patients. Out of the 3370 recruited patients, 1033 had metabolic syndrome and 1177 had neither metabolic syndrome nor diabetes. When compared with patients with no metabolic syndrome or diabetes, patients with metabolic syndrome had higher pulse pressure (59±14 vs. 55±14 mm Hg) and heart rate (75.2±11.0 vs. 72.5±10.0 beats per min) (Ppulse pressure, which may at least in part reflect increased arterial stiffness and increased sympathetic tone. This may contribute, to some extent, to explaining the increased cardiovascular risk attributed to the presence of metabolic syndrome.

  2. Consumer perception of the use of high-pressure processing and pulsed electric field technologies in food production

    DEFF Research Database (Denmark)

    Nielsen, Henriette Boel; Sonne, Anne-Mette; Grunert, Klaus G.

    2009-01-01

    on consumer attitudes towards high-pressure processing (HPP) and pulsed electric field (PEF) processing of food was carried out. In all 97 adults between 20 and 71 years of age participated in 12 focus groups conducted in Slovenia, Hungary, Serbia, Slovakia, Norway and Denmark using a common guideline...... showed that environmental friendliness and the more natural products were seen as the main advantages, while they were concerned about body and health, the higher price of the products, the lack of information about the technologies and a general scepticism. The study also shows that North European...

  3. Testing of a one dimensional model for Field II calibration

    DEFF Research Database (Denmark)

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2008-01-01

    to the calibrated Field II program for 1, 4, and 10 cycle excitations. Two parameter sets were applied for modeling, one real valued Pz27 parameter set, manufacturer supplied, and one complex valued parameter set found in literature, Alguer´o et al. [11]. The latter implicitly accounts for attenuation. Results show......Field II is a program for simulating ultrasound transducer fields. It is capable of calculating the emitted and pulse-echoed fields for both pulsed and continuous wave transducers. To make it fully calibrated a model of the transducer’s electro-mechanical impulse response must be included. We...... examine an adapted one dimensional transducer model originally proposed by Willatzen [9] to calibrate Field II. This model is modified to calculate the required impulse responses needed by Field II for a calibrated field pressure and external circuit current calculation. The testing has been performed...

  4. Probing of Fast Chemical Dynamics at High Pressures and Temperatures using Pulsed Laser Techniques

    Science.gov (United States)

    2014-12-17

    and dissociation of ammonia at high pressure and high temperature, The Journal of Chemical Physics, (08 2012): 0. doi: 10.1063/1.4742340 Ross Howie...Alexander Goncharov, Mohammad F. Mahmood, Synthesis of Energetic Nitrogen and Hydrogen Compounds Using High Pressure and Multiphoton Absorption, Poster...27, 2014. Alexander Goncharov, High-pressure synthesis of novel materials with new bonding patterns and unusual stoichiometries, Invited talk

  5. Effect of ambient gas pressure on pulsed laser ablation plume dynamics and ZnTe film growth

    Energy Technology Data Exchange (ETDEWEB)

    Rouleau, C.M.; Lowndes, D.H.; Geohegan, D.B.; Allard, L.F. [Oak Ridge National Lab., TN (United States); Strauss, M.A.; Cao, S.; Pedraza, A.J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Puretzky, A.A. [Inst. of Spectroscopy, Troitsk (Russian Federation)

    1995-12-01

    Epitaxial thin films of nitrogen-doped p-ZnTe were grown on single-crystal, semi-insulating Ga-As substrates via pulsed laser ablation of a stoichiometric ZnTe target. Both low pressure nitrogen ambients and high vacuum were used. Results of in situ reflection high energy electron diffraction (RHEED) and time-resolved ion probe measurements have been compared with ex situ Hall effect and transmission electron microscopy (TEM) measurements. A strong correlation was observed between the nature of the film`s surface during growth (2-D vs. 3-D, assessed via RHEED) and the ambient gas pressures employed during deposition. The extended defect content (assessed via cross-sectional TEM) in the region >150 mn from the film/substrate interface was found to increase with the ambient gas pressure during deposition, which could not be explained by lattice mismatch alone. At sufficiently high pressures, misoriented, columnar grains developed which were not only consistent with the RHEED observations but also were correlated with a marked decrease in Hall mobility and a slight decrease in hole concentration. Ion probe measurements, which monitored the attenuation and slowing of the ion current arriving at the substrate surface, indicated that for increasing nitrogen pressure the fast (vacuum) velocity distribution splits into a distinct fast and two collisionally-slowed components or modes. Gas controlled variations in these components mirrored trends in electrical properties and microstructural measurements.

  6. Pressure waves in liquid mercury target from pulsed heat loads and the possible way controlling their effects

    Energy Technology Data Exchange (ETDEWEB)

    Ni, L.; Skala, K. [Paul Scherrer Institute, Villingen (Switzerland)

    1996-06-01

    In ESS project liquid metals are selected as the main target for the pulsed spallation neutron source. Since the very high instantaneous energy is deposited on the heavy molten target in a very short period time, pressure waves are generated. They travel through the liquid and cause high stress in the container. Also, additional stress should be considered in the wall which is the result of direct heating of the target window. These dynamic processes were simulated with computational codes with the static response being analized first. The total resulting dynamic wall stress has been found to have exceeded the design stress for the selected container material. Adding a small amount of gas bubbles in the liquid could be a possible way to reduce the pressure waves.

  7. Shock Tube Investigation of Pressure and Ion Sensors Used in Pulse Detonation Engine Research

    Science.gov (United States)

    2004-06-01

    is a gas which follows the equation RTP ρ= and is generally applied to gases at low temperatures and pressures ( Cengel and Boles, 2002:88). A non...ideal or real gas does not follow this equation at sufficiently high temperature or pressure ( Cengel and Boles, 2002:622). This is the case when the

  8. Continuous Monitoring of Cerebrovascular Reactivity Using Pulse Waveform of Intracranial Pressure

    NARCIS (Netherlands)

    Aries, M.J.H.; Czosnyka, Marek; Budohoski, Karol P.; Kolias, Angelos G.; Radolovich, Danila K.; Lavinio, Andrea; Pickard, John D.; Smielewski, Peter

    2012-01-01

    Guidelines for the management of traumatic brain injury (TBI) call for the development of accurate methods for assessment of the relationship between cerebral perfusion pressure (CPP) and cerebral autoregulation and to determine the influence of quantitative indices of pressure autoregulation on out

  9. HISTOLOGICAL STUDY OF MEDIUM SIZED ARTERIES OF NECK IN RELATION WITH THEIR PULSE PRESSURE AND PULSATORY POWER

    Directory of Open Access Journals (Sweden)

    Prerana

    2014-11-01

    Full Text Available : INTRODUCTION: There are several studies on the microstructure of main arteries of the body but limited have been dealt with the neck arteries. It has been mentioned that the vascular pathologies like the thrombo-embolism, atherosclerosis and infarction are common in the branches of vertebral and internal carotid artery as compared to the branches of external carotid artery. OBJECTIVE: To study the histological structure of the 3 medium sized arteries of neck namely external carotid, internal carotid and vertebral artery, calculation of their mean pulse pressure and pulsatory power and to find any association between them if present. METHOD: Fresh samples of external carotid, internal carotid and vertebral artery each measuring 10mm in length were taken from five cadavers and prepared for histological examination under microscope using orcein and H&E stain. The mean pressure and pulsatory power of these arteries were calculated by taking the measurements such as wall thickness, lumen circumference, arterial wall area, and smooth muscle fibre density in tunica media in that arterial segment. RESULT: The pulsatory power of external carotid artery, internal carotid artery and vertebral artery is found to be 120, 273.3, 400 Joules /heart beat and the mean pressure is 17.1 mm Hg, 27.3 mm Hg and 33.3 mm Hg respectively. CONCLUSION: The thickness of tunica media of an artery is directly proportional to its pulsatory power. The mean pulse pressure, pulsatory power as well the number of smooth muscles fibres in tunica media are more in internal carotid artery and vertebral artery in comparison to external carotid artery. It may be a very important reason why vascular pathologies are less common in branches of external carotid as compare to internal carotid and vertebral artery.

  10. Influence of Surface Resistivity and Temperature on Variation with Time of Current Pulses in Air at Optimum Pressure

    Directory of Open Access Journals (Sweden)

    S.G. Pimpale

    1977-04-01

    Full Text Available The variation of discharge current pulses with the surface nature of electrodes has been investigated by producing discharge in the intense ionizing zone of two ozonizers (A&B containing pure, dry air at a pressure of 4 & 10mm of mercury respectively. The course of reaction in the tube A showed that the periodic rise and fall of discharge counts through a series of recurrences whose amplitude varied randomly. During this reaction, steady potential, temperature of the electrolytic bath, counting time and pulse height were kept fixed. The phenomenon obtained for both the tubes is produced within a critical range of conditions. The results have been interpreted on the basis of activated adsorption at a temperature of 90 degree and 100 degree Centigrade and discussed on the theoretical grounds of change of surface resistivity upon the glass walls. Use of different coatings on annular surface in the same system with appropriate levels of electrolytic solution for a definite value of height-pulses and temperature, etc. shows significant variations in the discharge counts.

  11. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    Science.gov (United States)

    Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-05-01

    In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determined, with the notable result that there exists a minimum and maximum gap distance for its existence at a given ambient gas temperature. The minimum gap distance increases with decreasing gas temperature, whereas the maximum does not vary appreciably. To explain the experimental results, an analytical model is developed to explain the corona-to-glow (C-G) and glow-to-spark (G-S) transitions. The C-G transition is analyzed in terms of the avalanche-to-streamer transition and the breakdown field during the conduction phase following the establishment of a conducting channel across the discharge gap. The G-S transition is determined by the thermal ionization instability, and we show analytically that this transition occurs at a certain reduced electric field for the NRP discharges studied here. This model shows that the electrode geometry plays an important role in the existence of the NRP glow regime at a given gas temperature. We derive a criterion for the existence of the NRP glow regime as a function of the ambient gas temperature, pulse repetition frequency, electrode radius of curvature, and interelectrode gap distance.

  12. Study of plasma pressure evolution driven by strong picosecond laser pulse

    Science.gov (United States)

    Li, M.; Wang, J. X.; Xu, Y. X.; Zhu, W. J.

    2017-01-01

    Through one dimensional relativistic particle-in-cell simulation of strong laser interaction with the solid-density plasma, the evolution of the plasma impact pressure behind a thin foil has been investigated in details. An energy-compression mechanism has been proposed to help optimizing the laser and plasma parameters. It has been found that by using a picosecond laser with intensity 1015 W cm-2, an impact pressure as high as several hundreds of GPa order of magnitude can be obtained. The numerical analysis demonstrates that the peak pressure is mainly resulted from the ion contribution. These results are of potential application to the laser loading upon solids in order to study the material properties under extra-high dynamic pressure.

  13. Cerebrospinal fluid pulse pressure and craniospinal dynamics : a theoretical, clinical and experimental study

    NARCIS (Netherlands)

    C.J.J. Avezaat (Cees); J.H.M. van Eijndhoven (Johannes Hubertus Marcellianus)

    1984-01-01

    textabstractSince the introduction of continuous recording of intracranial pressure (ICP) in neurosurgical practice (Guillaume and Janny, 1951; Lundberg, 1960) this method has greatly contributed to clinical research in the field of intracranial hypertension. Numerous publications have enriched the

  14. Effects of Acupuncture Stimulation on the Radial artery’s Pressure Pulse Wave in Healthy Young Participants: Protocol for a prospective, single-Arm, Exploratory, Clinical Study

    OpenAIRE

    Jae-Young Shin; Boncho Ku; Tae-Hun Kim; Jang Han Bae; Min-Ho Jun; Jun-Hwan Lee; Kim, Jaeuk U.

    2016-01-01

    Introduction: This study aims to investigate the effects of acupuncture stimulation on the radial artery’s pressure pulse wave, along with various hemodynamic parameters, and to explore the possible underlying mechanism of pulse diagnosis in healthy participants in their twenties. Methods and analysis: This study is a prospective, single-arm, exploratory clinical study. A total of 25 healthy participants, without regard to gender, in their twenties will be recruited by physicians. Written inf...

  15. High pulse pressure is not associated with abnormal activation of the renin-angiotensin-aldosterone system in repaired aortic coarctation.

    Science.gov (United States)

    Pedersen, T A L; Pedersen, E B; Munk, K; Hjortdal, V E; Emmertsen, K; Andersen, N H

    2015-04-01

    We investigated the relationship between pulse pressure (PP)--a surrogate marker of arterial stiffness-and activity of the renin-angiotensin-aldosterone system (RAAS) in adult patients with repaired coarctation and normal left ventricular (LV) function. A total of 114 patients (44 (26-74) years, 13 (0.1-40) years at repair) and 20 healthy controls were examined with 24-h ambulatory blood pressure monitoring, echocardiography, vasoactive hormone levels and magnetic resonance of the thoracic aorta. Forty-one patients (36%) were taking antihypertensives (28 RAAS inhibitors). Fifty-one had mean 24-h blood pressures >130/80 mm Hg. Hypertension was not associated with age at repair (P=0.257). Patients had higher PP and LV mass compared with controls (52±11 vs. 45±5 mm Hg and 221±71 vs. 154±55 g, respectively; both Pcoarctation have increased PP and LV mass compared with controls. PP increased with increasing recoarctation. Hypertension was present also in the absence of recoarctation. These changes could not be explained by abnormal activation of the RAAS.

  16. Impact of extracorporeal blood flow rate on blood pressure, pulse rate and cardiac output during haemodialysis

    DEFF Research Database (Denmark)

    Schytz, Philip Andreas; Mace, Maria Lerche; Soja, Anne Merete Boas

    2015-01-01

    BACKGROUND: If blood pressure (BP) falls during haemodialysis (HD) [intradialytic hypotension (IDH)] a common clinical practice is to reduce the extracorporeal blood flow rate (EBFR). Consequently the efficacy of the HD (Kt/V) is reduced. However, only very limited knowledge on the effect of redu...

  17. Learning Experience for Calibration Speciifcation for Superconducting Pulsed Fourier Transform Nuclear Magnetic Resonance Spectrometers%超导脉冲傅里叶变换核磁共振谱仪校准规范解读

    Institute of Scientific and Technical Information of China (English)

    廖鹏; 张伟; 黄挺

    2015-01-01

    Calibration Specification for Superconducting Pulsed Fourier Transform Nuclear Magnetic Resonance Spectrometers JJF1448–2014 was conducted. Through the analysis of the main technical indicators of the superconducting pulsed Fourier transform nuclear magnetic resonance spectrometers, the reasons of ethyl benzene certified reference material,chloroform certified reference material,deuterated benzene/p-dioxane certified reference material and the features and advantages of calibration method in calibration specification JJF 1448–2014 were expounded. New standard calibration method is reasonable, the standards materials have simple structure, and can calibrate the main technical index of instruments, the efficiency was improved, it meets the most of the Fourier transform nuclear magnetic resonance (NMR) calibration requirements.%对超导脉冲傅里叶变换核磁共振谱仪校准规范JJF 1448–2014进行了解读.通过对超导脉冲傅里叶变换核磁共振谱仪主要技术指标的类型分析,说明了采用乙基苯溶液标准物质、氯仿溶液标准物质、氘代苯/p-二氧六环溶液标准物质被采用的原因及其在JJF 1448–2014校准方法中的特点及优势.新规范校准方法合理、所采用的标准物质结构简单、能够对仪器的主要技术指标进行校准,提高了效率,满足大部分傅里叶变换核磁共振的校准要求.

  18. High-efficiency generation of pulsed Lyman-α radiation by resonant laser wave mixing in low pressure Kr-Ar mixture.

    Science.gov (United States)

    Saito, Norihito; Oishi, Yu; Miyazaki, Koji; Okamura, Kotaro; Nakamura, Jumpei; Louchev, Oleg A; Iwasaki, Masahiko; Wada, Satoshi

    2016-04-04

    We report an experimental generation of ns pulsed 121.568 nm Lyman-α radiation by the resonant nonlinear four-wave mixing of 212.556 nm and 845.015 nm radiation pulses providing a high conversion efficiency 1.7x10-3 with the output pulse energy 3.6 μJ achieved using a low pressure Kr-Ar mixture. Theoretical analysis shows that this efficiency is achieved due to the advantage of using (i) the high input laser intensities in combination with (ii) the low gas pressure allowing us to avoid the onset of full-scale discharge in the laser focus. In particular, under our experimental conditions the main mechanism of photoionization caused by the resonant 2-photon 212.556 nm radiation excitation of Kr atoms followed by the 1-photon ionization leads to ≈17% loss of Kr atoms and efficiency loss only by the end of the pulse. The energy of free electrons, generated by 212.556 nm radiation via (2 + 1)-photon ionization and accelerated mainly by 845.015 nm radiation, remains during the pulse below the level sufficient for the onset of full-scale discharge by the electron avalanche. Our analysis also suggests that ≈30-fold increase of 845.015 nm pulse energy can allow one to scale up the L-α radiation pulse energy towards the level of ≈100 μJ.

  19. Simulation of subnanosecond streamers in atmospheric-pressure air: Effects of polarity of applied voltage pulse

    Science.gov (United States)

    Babaeva, N. Yu.; Naidis, G. V.

    2016-08-01

    Results of simulation of subnanosecond streamer propagation in corona gap configuration, obtained in the framework of 2D fluid model, are presented. Effects related with the polarity of a voltage pulse applied to the stressed electrode are discussed. It is argued that these effects (dependence of the discharge current and propagation velocity on the polarity of applied voltage) observed in experiments can be attributed to the difference in initial (preceding the streamer formation) distributions of charged species inside the gap. This difference can be caused by preionization (at negative polarity) of the gas inside the discharge gap by runaway electrons. Calculated streamers have large widths (up to 1 cm) and move with velocities in the range of 109-1010 cm s-1, similar to experimental data.

  20. Amorphous carbon film deposition on inner surface of tubes using atmospheric pressure pulsed filamentary plasma source

    CERN Document Server

    Pothiraja, Ramasamy; Awakowicz, Peter

    2011-01-01

    Uniform amorphous carbon film is deposited on the inner surface of quartz tube having the inner diameter of 6 mm and the outer diameter of 8 mm. A pulsed filamentary plasma source is used for the deposition. Long plasma filaments (~ 140 mm) as a positive discharge are generated inside the tube in argon with methane admixture. FTIR-ATR, XRD, SEM, LSM and XPS analyses give the conclusion that deposited film is amorphous composed of non-hydrogenated sp2 carbon and hydrogenated sp3 carbon. Plasma is characterized using optical emission spectroscopy, voltage-current measurement, microphotography and numerical simulation. On the basis of observed plasma parameters, the kinetics of the film deposition process is discussed.

  1. Generation of heavy ion beams using femtosecond laser pulses in the target normal sheath acceleration and radiation pressure acceleration regimes

    Science.gov (United States)

    Petrov, G. M.; McGuffey, C.; Thomas, A. G. R.; Krushelnick, K.; Beg, F. N.

    2016-06-01

    Theoretical study of heavy ion acceleration from sub-micron gold foils irradiated by a short pulse laser is presented. Using two dimensional particle-in-cell simulations, the time history of the laser pulse is examined in order to get insight into the laser energy deposition and ion acceleration process. For laser pulses with intensity 3 × 10 21 W / cm 2 , duration 32 fs, focal spot size 5 μm, and energy 27 J, the calculated reflection, transmission, and coupling coefficients from a 20 nm foil are 80%, 5%, and 15%, respectively. The conversion efficiency into gold ions is 8%. Two highly collimated counter-propagating ion beams have been identified. The forward accelerated gold ions have average and maximum charge-to-mass ratio of 0.25 and 0.3, respectively, maximum normalized energy 25 MeV/nucleon, and flux 2 × 10 11 ions / sr . An analytical model was used to determine a range of foil thicknesses suitable for acceleration of gold ions in the radiation pressure acceleration regime and the onset of the target normal sheath acceleration regime. The numerical simulations and analytical model point to at least four technical challenges hindering the heavy ion acceleration: low charge-to-mass ratio, limited number of ions amenable to acceleration, delayed acceleration, and high reflectivity of the plasma. Finally, a regime suitable for heavy ion acceleration has been identified in an alternative approach by analyzing the energy absorption and distribution among participating species and scaling of conversion efficiency, maximum energy, and flux with laser intensity.

  2. Comparison of noninvasive pulse transit time estimates as markers of blood pressure using invasive pulse transit time measurements as a reference.

    Science.gov (United States)

    Gao, Mingwu; Olivier, N Bari; Mukkamala, Ramakrishna

    2016-05-01

    Pulse transit time (PTT) measured as the time delay between invasive proximal and distal blood pressure (BP) or flow waveforms (invasive PTT [I-PTT]) tightly correlates with BP PTT estimated as the time delay between noninvasive proximal and distal arterial waveforms could therefore permit cuff-less BP monitoring. A popular noninvasive PTT estimate for this application is the time delay between ECG and photoplethysmography (PPG) waveforms (pulse arrival time [PAT]). Another estimate is the time delay between proximal and distal PPG waveforms (PPG-PTT). PAT and PPG-PTT were assessed as markers of BP over a wide physiologic range using I-PTT as a reference. Waveforms for determining I-PTT, PAT, and PPG-PTT through central arteries were measured from swine during baseline conditions and infusions of various hemodynamic drugs. Diastolic, mean, and systolic BP varied widely in each subject (group average (mean ± SE) standard deviation between 25 ± 2 and 36 ± 2 mmHg). I-PTT correlated well with all BP levels (group average R(2) values between 0.86 ± 0.03 and 0.91 ± 0.03). PPG-PTT also correlated well with all BP levels (group average R(2) values between 0.81 ± 0.03 and 0.85 ± 0.02), and its R(2) values were not significantly different from those of I-PTT PAT correlated best with systolic BP (group average R(2) value of 0.70 ± 0.04), but its R(2) values for all BP levels were significantly lower than those of I-PTT (P < 0.005) and PPG-PTT (P < 0.02). The pre-ejection period component of PAT was responsible for its inferior correlation with BP In sum, PPG-PTT was not different from I-PTT and superior to the popular PAT as a marker of BP.

  3. Condensation of ablation plumes in the irradiation of metals by high-intensity nanosecond laser pulses at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kozadaev, K V [A.N. Sevchenko Institute of Applied Physical Problems, Belarusian State University, Minsk (Belarus)

    2016-01-31

    The Anisimov–Luk'yanchuk model is adapted for describing the condensation of vapour-plasma plumes produced in the irradiation of metal targets by high-intensity (10{sup 8} – 10{sup 10} W cm{sup -2}) nanosecond (10 – 100 ns) pulses at atmospheric pressure. The resultant data suggest that the initial stages of the development of metal ablation plumes correspond with a high degree of accuracy to the Zel'dovich–Raizer theory of dynamic condensation; however, at the stage of the ablation plume decay, the liquid-droplet phase is formed primarily by coalescence of 'nuclei'. (interaction of laser radiation with matter. laser plasma)

  4. Researches regarding a pressure pulse generator as a segment of model for a weighing in motion system

    Science.gov (United States)

    Mardare, I.; Tiţa, I.; Pelin, R. I.

    2016-08-01

    There are many types of weighing in motion systems: with strain gauges, piezoelectric type, with optical fibre, capacitive etc. Although one of them proved to be reliable, many research teams all over the world are interested in finding new types or improving the existing ones. In this paper is presented a hydraulic Weigh-In-Motion sensor composed of a metal vessel filled with hydraulic oil connected to an accumulator through a pipe. Vehicle tires press on the deformable upper wall and pressure pulses generated in this way provides information about the load. In this paper are presented: a structure for an experimental model, the block diagram for numerical simulation, experimental model and some experimental results.

  5. Evaluation of the effect of systolic blood pressure and pulse pressure on cognitive function: the Women's Health and Aging Study II.

    Directory of Open Access Journals (Sweden)

    Sevil Yasar

    Full Text Available BACKGROUND: Evidence suggests that elevated systolic blood pressure (SBP and pulse pressure (PP in midlife is associated with increased risk for cognitive impairment later in life. There is mixed evidence regarding the effects of late life elevated SBP or PP on cognitive function, and limited information on the role of female gender. METHODS/PRINCIPAL FINDINGS: Effects of SBPand PPon cognitive abilities at baseline and over a 9-year period were evaluated in 337 non-demented community-dwelling female participants over age 70 in the Women's Health and Aging Study II using logistic and Cox proportional hazards regression analyses. Participants aged 76-80 years with SBP≥160 mmHg or PP≥84 mmHg showed increased incidence of impairment on Trail Making Test-Part B (TMT, Part B, a measure of executive function, over time when compared to the control group that included participants with normal and pre-hypertensive SBP (<120 and 120-139 mmHg or participants with low PP (<68 mmHg (HR = 5.05 [95%CI = 1.42, 18.04], [HR = 5.12 [95%CI = 1.11; 23.62], respectively. Participants aged 70-75 years with PP≥71 mmHg had at least a two-fold higher incidence of impairment on HVLT-I, a measure of verbal learning, over time when compared to participants with low PP (<68 mmHg (HR = 2.44 [95%CI = 1.11, 5.39]. CONCLUSIONS/SIGNIFICANCE: Our data suggest that elevated SBP or PP in older non-demented women increases risk for late-life cognitive impairment and that PP could be used when assessing the risk for impairment in cognitive abilities. These results warrant further, larger studies to evaluate possible effects of elevated blood pressure in normal cognitive aging.

  6. THE EFFECTS OF PULSE BIAS VOLTAGE AND N2 PARTIAL PRESSURE ON TiAIN FILMS OF ARC ION PLATING (AIP)

    Institute of Scientific and Technical Information of China (English)

    M.S. Li; S.L. Zhu; Fuhui Wang; C. Sun; L.S. Wen

    2001-01-01

    Owing to the characteristics of arc ion plating(AIP) technique, the structure and com-position of TiAlN films can be tailored by controlling of various parameters such ascompositions of target materials, N2 partial pressure, substrate bias and so on. ln thisstudy, several titanium aluminum nitride films were deposited on 1Cr11Ni2 W2Mo Vsteel for compressor blade of areo-engine under different d.c pulse bias voltage and ni-trogen partial pressure. The effects of substrate pulse bias and nitrogen partial pressureon the deposition rate, droplet formation, microstruture and elemental component ofthe films were investigated.

  7. Energy calibration via correlation

    CERN Document Server

    Maier, Daniel

    2015-01-01

    The main task of an energy calibration is to find a relation between pulse-height values and the corresponding energies. Doing this for each pulse-height channel individually requires an elaborated input spectrum with an excellent counting statistics and a sophisticated data analysis. This work presents an easy to handle energy calibration process which can operate reliably on calibration measurements with low counting statistics. The method uses a parameter based model for the energy calibration and concludes on the optimal parameters of the model by finding the best correlation between the measured pulse-height spectrum and multiple synthetic pulse-height spectra which are constructed with different sets of calibration parameters. A CdTe-based semiconductor detector and the line emissions of an 241 Am source were used to test the performance of the correlation method in terms of systematic calibration errors for different counting statistics. Up to energies of 60 keV systematic errors were measured to be le...

  8. Noninvasive LV pressure estimation using subharmonic emissions from microbubbles.

    Science.gov (United States)

    Dave, Jaydev K; Halldorsdottir, Valgerdur G; Eisenbrey, John R; Raichlen, Joel S; Liu, Ji-Bin; McDonald, Maureen E; Dickie, Kris; Wang, Shumin; Leung, Corina; Forsberg, Flemming

    2012-01-01

    To develop a new noninvasive approach to quantify left ventricular (LV) pressures using subharmonic emissions from microbubbles, an ultrasound scanner was used in pulse inversion grayscale mode; unprocessed radiofrequency data were obtained with pulsed wave Doppler from the aorta and/or LV during Sonazoid infusion. Subharmonic data (in dB) were extracted and processed. Calibration factor (mm Hg/dB) from the aortic pressure was used to estimate LV pressures. Errors ranged from 0.19 to 2.50 mm Hg when estimating pressures using the aortic calibration factor, and were higher (0.64 to 8.98 mm Hg) using a mean aortic calibration factor. Subharmonic emissions from ultrasound contrast agents have the potential to noninvasively monitor LV pressures.

  9. Pulse Pressure magnifies the effect of COMTVal158Met on 15 Year Episodic Memory Trajectories

    Directory of Open Access Journals (Sweden)

    Ninni ePersson

    2016-03-01

    Full Text Available We investigated whether a physiological marker of cardiovascular health, pulse pres­sure (PP, and age magnified the effect of the functional COMT Val158Met (rs4680 pol­ymor­phism on 15-year cognitive trajectories (episodic memory [EM], visuospatial ability, and se­man­tic memory using data from 1585 non-demented adults from the Betula study. A mul­tiple-group growth model was specified to gauge individual differences in change. The allelic variants showed negligible differences across the cognitive markers in average trends. The older portion of the sample selectively age-magnified the effects of Val158Met on EM changes, resulting in greater decline in Val compared to homozygote Met carriers. This effect was attenuated by sta­tistical control for PP. Further, PP mod­erated the effects of COMT on 15-year EM trajectories, resulting in greater decline in Val carriers, even after accounting for the confounding effects of sex, education, cardiovascular diseases (dia­betes, stroke, and hypertension, and chronological age, controlled for practice gains. The effect was still present after excluding individuals with a history of cardiovascular diseases. The effects of cognitive change were not moderated by any other covariates. This report underscores the importance of addressing synergistic effects in nor­mal cognitive aging, as the addition thereof may even place healthy individuals at greater risk for memory decline.

  10. Reconstructing Winter North Pacific Sea-Level Pressure Anomalies Over the Past Three Centuries Using a New Calibration Method with the Eclipse and Mt. Logan Ice Cores

    Science.gov (United States)

    Kelsey, E. P.; Wake, C. P.; Osterberg, E. C.

    2012-12-01

    A deeper understanding of the behavior of North Pacific extratropical cyclones and anticyclones prior to the instrumental era is needed to advance our understanding of North Pacific climate variability. To help achieve this objective, we develop and use a new nonlinear ice core calibration procedure with the Eclipse (3017 m a.s.l.) and Mt. Logan (5400 m a.s.l.) ice core records from Yukon, Canada to isolate the ranges of ice core values that are consistently associated with North Pacific wintertime sea-level pressure (SLP) anomalies. Over the calibration period (1872-2001), each ice core record is ranked and divided into 10 groups of 13 years. Then for each group, the frequency of positive and negative SLP anomalies at each grid point is contoured and the composite mean SLP anomaly values are shaded. These plots elucidate areas where statistically significant SLP anomalies occur frequently in association with groups of ice core values. This new calibration procedure shows that the lowest and the two highest groups of Mt. Logan annual [Na+] are sensitive to SLP anomalies in the central and eastern Pacific and the second lowest [Na+] group is sensitive to western Pacific SLP anomalies. The highest and lowest Eclipse cold-season accumulation groups are most sensitive to SLP anomalies more distant in the western and central Pacific. This result is surprising in light of stable isotope studies suggesting a more distant moisture source for Mt. Logan. A reconstruction using these calibrated records indicates the Aleutian Low was predominantly weaker than average between 1699-1871. Our results highlight that having these geographically close ice core records is important to developing a deeper understanding of North Pacific climate variability.

  11. Analysis of Self-Terminated Pressure-Driven Quantum Point Contacts with Ultrafast Optical Pulses

    Science.gov (United States)

    Soltani, Fatemeh; Wlasenko, Alex; Steeves, Geoff

    2009-05-01

    A self-terminated electrochemical method was used to fabricate atomic-scale contacts between two Au electrodes in a microfluidic channel. The conductance of the contacts varies in a stepwise fashion. The mechanism works by a pressure-driven flow parallel with a pair of Au electrodes with a 100 μm gap in an electrolyte of HCl. Without applied flow, dendrite growth and dense branching morphology were typically observed at the cathode. The addition of applied pressure-driven flow resulted in a densely packed gold structure that filled the channel. The electrochemical fabrication approach introduces large variance in the formation and location of individual junctions. Understanding and controlling this process will enable the precise positioning of reproducible geometries into nano-electronic devices. To investigate the high speed behaviour of a QPC, it can be integrated with a transmission line structure patterned on a photoconductive GaAs substrate. The nonlinear conductance of the QPC (due to the finite density of states of the conductors) can be examined and compared with recent theoretical studies. Samples are fabricated in situ using an electrochemical procedure to produce QPCs along the transmission line structure. This method may provide insight into Terahertz Optoelectronic devices and ultrafast communication systems.

  12. An experimental study on discharge characteristics in a pulsed-dc atmospheric pressure CH3OH/Ar plasma jet

    Science.gov (United States)

    Qian, Muyang; Liu, Sanqiu; Yang, Congying; Pei, Xuekai; Lu, Xinpei; Zhang, Jialiang; Wang, Dezhen

    2016-10-01

    Recently, C/H/Ar plasma discharges found enormous potential and possibility in carbonaceous compounds conversion and production. In this work, a pulsed-dc CH3OH/Ar plasma jet generated at atmospheric pressure is investigated by means of optical and electrical diagnosis concerning the variation of its basic parameters, absolute concentration of OH radicals, and plasma temperature with different CH3OH/Ar volume ratios, in the core region of discharge with needle-to-ring electrode configuration. The voltage-current characteristics are also measured at different CH3OH/Ar ratios. Laser-induced fluorescence (LIF) results here show that only small amounts of added methanol vapor to argon plasma (about 0.05% CH3OH/Ar volume ratio) is favorable for the production of OH radicals. The optical emission lines of CH, CN, and C2 radicals have been detected in the CH3OH/Ar plasma. And, the plasma temperatures increase with successive amount of added methanol vapor to the growth plasma. Moreover, qualitative discussions are presented regarding the mechanisms for methanol dissociation and effect of the CH3OH component on the Ar plasma discharge at atmospheric pressure.

  13. Acute effects of supramaximal exercise on carotid artery compliance and pulse pressure in young men and women.

    Science.gov (United States)

    Rossow, Lindy; Fahs, Christopher A; Guerra, Myriam; Jae, Sae Young; Heffernan, Kevin S; Fernhall, Bo

    2010-11-01

    The purpose of this study was to determine the cumulative effects of repeated cycling sprints (Wingate tests) on carotid compliance and blood pressure (BP). Fourteen young, healthy men and women completed this study. Vascular and hemodynamic measurements were taken at rest, 5 min following a first Wingate test, 25 min following the first Wingate test, 5 min following a second Wingate test, and 25 min following the second Wingate test. At each time point, the measurements taken included brachial and carotid pulse pressure (PP), heart rate, carotid artery maximum and minimum diameters, and carotid compliance. Carotid BP was obtained with applanation tonometry. Carotid diameters were obtained using ultrasonography and compliance was calculated from carotid diameters and BP. Carotid and brachial PP increased significantly (P sprint, carotid arterial compliance decreased significantly more than 5 min following the first sprint (P sprint reduces carotid artery compliance immediately after exercise. Performance of a second identical cycling sprint further compounds this vascular change, reducing carotid artery compliance beyond levels seen following a single cycling sprint.

  14. 轴承保持架低压脉冲真空氮碳共渗工艺%Low Pressure Pulse Vacuum Nitrocarburizing Process for Bearing Cages

    Institute of Scientific and Technical Information of China (English)

    刘斌; 张文朝; 郭长健

    2012-01-01

    The low pressure pulse vacuum nitrocarburizing process principles of bearing cages are analyzed, the orthogonal experiments are carried out about the influence of pulse process parameters on white layer depth and surface hardness , such as pulse amplitude, pressure holding time and total pulse time. The influence tends of pulse process parameters on white layer depth and surface hardness are studied through the methods of range analysis in orthogonal experiment , and the optimum pulse process parameters under the given test conditions are presented.%分析轴承保持架低压脉冲真空氮碳共渗工艺原理,对影响保持架表面白亮层深度和表面硬度的脉冲工艺参数:脉冲幅度、保压时间及总脉冲时间进行了正交试验.应用正交试验极差分析法分析了脉冲工艺参数与白亮层深度和表面硬度的影响趋势,最终确定出给定试验条件下的最佳脉冲工艺参数.

  15. The impact of arm position and pulse pressure on the validation of a wrist-cuff blood pressure measurement device in a high risk population

    Directory of Open Access Journals (Sweden)

    Ali Reza Khoshdel

    2010-03-01

    Full Text Available Ali Reza Khoshdel1,2, Shane Carney2, Alastair Gillies21Faculty of Medicine, Aja University of Medical Science, Tehran, Iran; 2John Hunter Hospital, Faculty of Health, The University of Newcastle, Newcastle, NS W, AustraliaAbstract: Despite the increasing popularity of blood pressure (BP wrist monitors for self-BP measurement at home, device validation and the effect of arm position remains an issue. This study focused on the validation of the Omron HEM-609 wrist BP device, including an evaluation of the impact of arm position and pulse pressure on BP measurement validation. Fifty patients at high risk for cardiovascular disease were selected (age 65 ± 10 years. Each patient had two measurements with a mercury sphygmomanometer and three measurements with the wrist BP device (wrist at the heart level while the horizontal arm supported [HORIZONTAL], hand supported on the opposite shoulder [SHOULDER], and elbow placed on a desk [DESK], in random order. The achieved systolic BP (SBP and diastolic BP (DBP wrist-cuff readings were compared to the mercury device and the frequencies of the readings within 5, 10, and 15 mmHg of the gold standard were computed and compared with the British Hypertension Society (BHS and Association for the Advancement of Medical Instrumentation (AAMI protocols. The results showed while SBP readings with HORIZONTAL and SHOULDER positions were significantly different from the mercury device (mean difference = 7.1 and 13.3 mmHg, respectively; P < 0.05, the DESK position created the closest reading to mercury (mean difference = 3.8, P > 0.1. Approximately 71% of SBP readings with the DESK position were within ±10 mmHg, whereas it was 62.5% and 34% for HORIZONTAL and SHOULDER positions, respectively. Wrist DBP attained category D with BHS criteria with all three arm positions. Bland–Altman plots illustrated that the wrist monitor systematically underestimated SBP and DBP values. However a reading adjustment of 5 and 10 mm

  16. Magnetic Ignition of Pulsed Gas Discharges in Air of Low Pressure in a Coaxial Plasma Gun

    Science.gov (United States)

    Thom, Karlheinz; Norwood, Joseph, Jr.

    1961-01-01

    The effect of an axial magnetic field on the breakdown voltage of a coaxial system of electrodes has been investigated by earlier workers. For low values of gas pressure times electrode spacing, the breakdown voltage is decreased by the application of the magnetic field. The electron cyclotron radius now assumes the role held by the mean free path in nonmagnetic discharges and the breakdown voltage becomes a function of the magnetic flux density. In this paper the dependence of the formative time lag as a function of the magnetic flux density is established and the feasibility of using a magnetic field for igniting high-voltage, high-current discharges is shown through theory and experiment. With a 36 microfarad capacitor bank charged to 48,000 volts, a peak current of 1.3 x 10( exp 6) amperes in a coaxial type of plasma gun was achieved with a current rise time of only 2 microseconds.

  17. Intra-Operative Fluid Management in Adult Neurosurgical Patients Undergoing Intracranial Tumour Surgery: Randomised Control Trial Comparing Pulse Pressure Variance (PPV) and Central Venous Pressure (CVP)

    Science.gov (United States)

    Salins, Serina Ruth; Kumar, Amar Nandha; Korula, Grace

    2016-01-01

    Introduction Fluid management in neurosurgery presents specific challenges to the anaesthesiologist. Dynamic para-meters like Pulse Pressure Variation (PPV) have been used successfully to guide fluid management. Aim To compare PPV against Central Venous Pressure (CVP) in neurosurgical patients to assess hemodynamic stability and perfusion status. Materials and Methods This was a single centre prospective randomised control trial at a tertiary care centre. A total of 60 patients undergoing intracranial tumour excision in supine and lateral positions were randomised to two groups (Group 1, CVP n=30), (Group 2, PPV n=30). Intra-operative fluid management was titrated to maintain baseline CVP in Group 1(5-10cm of water) and in Group 2 fluids were given to maintain PPV less than 13%. Acid base status, vital signs and blood loss were monitored. Results Although intra-operative hypotension and acid base changes were comparable between the groups, the patients in the CVP group had more episodes of hypotension requiring fluid boluses in the first 24 hours post surgery. {CVP group median (25, 75) 2400ml (1850, 3110) versus PPV group 2100ml (1350, 2200) p=0.03} The patients in the PPV group received more fluids than the CVP group which was clinically significant. {2250 ml (1500, 3000) versus 1500ml (1200, 2000) median (25, 75) (p=0.002)}. The blood loss was not significantly different between the groups The median blood loss in the CVP group was 600ml and in the PPV group was 850 ml; p value 0.09. Conclusion PPV can be used as a reliable index to guide fluid management in neurosurgical patients undergoing tumour excision surgery in supine and lateral positions and can effectively augment CVP as a guide to fluid management. Patients in PPV group had better hemodynamic stability and less post operative fluid requirement. PMID:27437329

  18. Comparing equivalent thermal, high pressure and pulsed electric field processes for mild pasteurization of orange juice. Part I: Impact on overall quality attributes

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Mastwijk, H.C.; Knol, J.J.; Quataert, M.C.J.; Vervoort, L.; Plancken, van der I.; Hendrickx, M.E.; Matser, A.M.

    2011-01-01

    Mild heat pasteurization, high pressure processing (HP) and pulsed electric field (PEF) processing of freshly squeezed orange juice were comparatively evaluated examining their impact on microbial load and quality parameters immediately after processing and during two months of storage. Microbial co

  19. Comparing equivalent thermal, high pressure and pulsed electric field processes for mild pasteurization of orange juice: Part II: Impact on specific chemical and biochemical quality parameters

    NARCIS (Netherlands)

    Vervoort, L.; Plancken, van der I.; Grauwet, T.; Timmermans, R.A.H.; Mastwijk, H.C.; Matser, A.M.; Hendrickx, M.E.; Loey, van A.

    2011-01-01

    The impact of thermal, high pressure (HP) and pulsed electric field (PEF) processing for mild pasteurization of orange juice was compared on a fair basis, using processing conditions leading to an equivalent degree of microbial inactivation. Examining the effect on specific chemical and biochemical

  20. Applicability of Pulse Pressure Variation during Unstable Hemodynamic Events in the Intensive Care Unit: A Five-Day Prospective Multicenter Study

    Directory of Open Access Journals (Sweden)

    Bertrand Delannoy

    2016-01-01

    Full Text Available Pulse pressure variation can predict fluid responsiveness in strict applicability conditions. The purpose of this study was to describe the clinical applicability of pulse pressure variation during episodes of patient hemodynamic instability in the intensive care unit. We conducted a five-day, seven-center prospective study that included patients presenting with an unstable hemodynamic event. The six predefined inclusion criteria for pulse pressure variation applicability were as follows: mechanical ventilation, tidal volume >7 mL/kg, sinus rhythm, no spontaneous breath, heart rate/respiratory rate ratio >3.6, absence of right ventricular dysfunction, or severe valvulopathy. Seventy-three patients presented at least one unstable hemodynamic event, with a total of 163 unstable hemodynamic events. The six predefined criteria for the applicability of pulse pressure variation were completely present in only 7% of these. This data indicates that PPV should only be used alongside a strong understanding of the relevant physiology and applicability criteria. Although these exclusion criteria appear to be profound, they likely represent an absolute contraindication of use for only a minority of critical care patients.

  1. On the motion of dayside auroras caused by a solar wind pressure pulse

    Directory of Open Access Journals (Sweden)

    A. Kozlovsky

    2005-02-01

    Full Text Available Global ultraviolet auroral images from the IMAGE satellite were used to investigate the dynamics of the dayside auroral oval responding to a sudden impulse (SI in the solar wind pressure. At the same time, the TV all-sky camera and the EISCAT radar on Svalbard (in the pre-noon sector allowed for detailed investigation of the auroral forms and the ionospheric plasma flow. After the SI, new discrete auroral forms appeared in the poleward part of the auroral oval so that the middle of the dayside oval moved poleward from about 70° to about 73° of the AACGM latitude. This poleward shift first occurred in the 15 MLT sector, then similar shifts were observed in the MLT sectors located more westerly, and eventually the shift was seen in the 6 MLT sector. Thus, the auroral disturbance "propagated" westward (from 15 MLT to 6 MLT at an apparent speed of the order of 7km/s. This motion of the middle of the auroral oval was caused by the redistribution of the luminosity within the oval and was not associated with the corresponding motion of the poleward boundary of the oval. The SI was followed by an increase in the northward plasma convection velocity. Individual auroral forms showed poleward progressions with velocities close to the velocity of the northward plasma convection. The observations indicate firstly a pressure disturbance propagation through the magnetosphere at a velocity of the order of 200km/s which is essentially slower than the velocity of the fast Alfvén (magnetosonic wave, and secondly a potential (curl-free electric field generation behind the front of the propagating disturbance, causing the motion of the auroras. We suggest a physical explanation for the slow propagation of the disturbance through the magnetosphere and a model for the electric field generation. Predictions of the model are supported by the global convection maps produced by the SuperDARN HF radars. Finally, the interchange instability and the eigenmode toroidal

  2. Numerical Analysis of Pressure Pulses in the Jerk Fuel Injection Systems

    Directory of Open Access Journals (Sweden)

    R. A. Baker

    2005-01-01

    Full Text Available Computer software has been developed and described in the present study of thorough parametric analysis and design of a mechanical diesel fuel injection system. The method is based on the numerical solution of one dimensional, unsteady, incompressible flow equations through the fuel pipe along with appropriate initial condition, pump end boundary condition and nozzle end boundary condition. Method of characteristics was used to solve the mathematical model by using a finite difference technique. The computer program has been written in Visual Fortran, which is capable of calculating pressure, velocity and other related parameters at different cam angles at any location of the fuel pipe, including pump and nozzle ends. First of all the numerical scheme was optimized and then its authenticity was verified by comparing its results with calculated and measured results available in the literature. The calculations of the present software were found to have improved agreement and acceptability. It was then used to make a thorough parametric analysis of a typical fuel injection system. The results have been presented in the form of graphs.

  3. Hydrophobic treatment on polymethylmethacrylate surface by nanosecond-pulse DBDs in CF{sub 4} at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Cheng [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Zhou, Yang [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Shao, Tao, E-mail: st@mail.iee.ac.cn [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Xie, Qing [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003 (China); Xu, Jiayu [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Wenjin [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-08-30

    Highlights: • Increase in hydrophobicity on PMMA is achieved after the DBD treatment in CF{sub 4}, and the water contact angle can increase from 68° to 100° after treatment. • Nanosecond-pulse DBD is used for the surface treatment and the power density is about 114.8 mW/cm{sup 2}. • The effects of applied voltage, CF{sub 4} flow, and time on plasma treatment are investigated. • Plasma treatment causes morphological change, significantly increases the roughness of the surface, and introduces fluorine-containing groups into the polymethylmethacrylate surface. • Hydrophobic behavior of the treated PMMA surface is slightly affected by the aging effect. - Abstract: Nanosecond-pulse dielectric barrier discharge (DBD) can provide non-thermal plasmas with extremely high energy and high density, which can result in a series of complicated physical and chemical reactions in the surface treatment of polymers. Therefore, in this paper, hydrophobic treatment of polymethylmethacrylate (PMMA) surface is conducted by nanosecond-pulse DBD in carbon tetrafluoride (CF{sub 4}) at atmospheric pressure. Investigations on surface morphology and chemical composition before and after the DBD treatment in CF{sub 4} are conducted with the contact angle measurement, atomic force microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectrometer. The effects of the applied voltage, CF{sub 4} flow rate, and treatment time on the hydrophobic modification are studied. Results show that the contact angles of the treated PMMA surface increases with the applied voltage, and it could be greatly affected by the CF{sub 4} flow rate and the treatment time. The water contact angle can increase from 68° to 100° after the treatment. Furthermore, both surface morphology and chemical composition of the PMMA samples are changed. Both the increase of the surface roughness and the occurrence of fluorine-containing functional groups on the PMMA surface treated by DBD in CF

  4. Estimating Hydraulic Conductivities in a Fractured Shale Formation from Pressure Pulse Testing and 3d Modeling

    Science.gov (United States)

    Courbet, C.; DICK, P.; Lefevre, M.; Wittebroodt, C.; Matray, J.; Barnichon, J.

    2013-12-01

    In the framework of its research on the deep disposal of radioactive waste in shale formations, the French Institute for Radiological Protection and Nuclear Safety (IRSN) has developed a large array of in situ programs concerning the confining properties of shales in their underground research laboratory at Tournemire (SW France). One of its aims is to evaluate the occurrence and processes controlling radionuclide migration through the host rock, from the disposal system to the biosphere. Past research programs carried out at Tournemire covered mechanical, hydro-mechanical and physico-chemical properties of the Tournemire shale as well as water chemistry and long-term behaviour of the host rock. Studies show that fluid circulations in the undisturbed matrix are very slow (hydraulic conductivity of 10-14 to 10-15 m.s-1). However, recent work related to the occurrence of small scale fractures and clay-rich fault gouges indicate that fluid circulations may have been significantly modified in the vicinity of such features. To assess the transport properties associated with such faults, IRSN designed a series of in situ and laboratory experiments to evaluate the contribution of both diffusive and advective process on water and solute flux through a clay-rich fault zone (fault core and damaged zone) and in an undisturbed shale formation. As part of these studies, Modular Mini-Packer System (MMPS) hydraulic testing was conducted in multiple boreholes to characterize hydraulic conductivities within the formation. Pressure data collected during the hydraulic tests were analyzed using the nSIGHTS (n-dimensional Statistical Inverse Graphical Hydraulic Test Simulator) code to estimate hydraulic conductivity and formation pressures of the tested intervals. Preliminary results indicate hydraulic conductivities of 5.10-12 m.s-1 in the fault core and damaged zone and 10-14 m.s-1 in the adjacent undisturbed shale. Furthermore, when compared with neutron porosity data from borehole

  5. 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.

  6. The relationship of pulse pressure and left ventricular funcion in hypertension patients%高血压患者脉压差与左心功能的关系

    Institute of Scientific and Technical Information of China (English)

    杨文; 王浩; 刘志发

    2003-01-01

    AIM:Discuss the relationship of pulse pressure and left ventricular function in hypertensive patients.METHODS:We observed the relationship of the pulse pressure and the times of again occurred coronary artery diseases, left ventricular fore and after span, left ventricular back wall thickness and left ventricular ejection fraction(EF) by color Doppler ultrasound in hypertensive patients. RESULTS:The times of again occurred coronary artery diseases, the left ventricular fore and after span and left ventricular EF of each pulse pressure group were significantly difference(P< 0.05, P< 0.01). CONCLUSION:The pulse pressure may take part in the further impair of left ventricular function coronary artery diseases.Control the pulse pressure coronary artery diseases have an important meaning in decreasing the further impair of left ventricular function.

  7. Raman spectroscopic measurements of CO2 density: Experimental calibration with high-pressure optical cell (HPOC) and fused silica capillary capsule (FSCC) with application to fluid inclusion observations

    Science.gov (United States)

    Wang, X.; Chou, I.-Ming; Hu, W.; Burruss, R.C.; Sun, Q.; Song, Y.

    2011-01-01

    Raman spectroscopy is a powerful method for the determination of CO2 densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO2 Fermi diad split (??, cm-1) and CO2 density (??, g/cm3) has been documented by several previous studies. However, significant discrepancies exist among these studies mainly because of inconsistent calibration procedures and lack of measurements for CO2 fluids having densities between 0.21 and 0.75g/cm3, where liquid and vapor phases coexist near room temperature.In this study, a high-pressure optical cell and fused silica capillary capsules were used to prepare pure CO2 samples with densities between 0.0472 and 1.0060g/cm3. The measured CO2 Fermi diad splits were calibrated with two well established Raman bands of benzonitrile at 1192.6 and 1598.9cm-1. The relationship between the CO2 Fermi diad split and density can be represented by: ??=47513.64243-1374.824414????+13.25586152????2-0.04258891551????3 (r2=0.99835, ??=0.0253g/cm3), and this relationship was tested by synthetic fluid inclusions and natural CO2-rich fluid inclusions. The effects of temperature and the presence of H2O and CH4 on this relationship were also examined. ?? 2011 Elsevier Ltd.

  8. Design, Construction and Calibration of a Near-Infrared Four-Color Pyrometry System for Laser-Driven High Pressure Experiments

    Science.gov (United States)

    Ali, S. J.; Jeanloz, R.; Collins, G.; Spaulding, D. K.

    2010-12-01

    Current dynamic compression experiments, using both quasi-isentropic and shock-compression, allow access to pressure-temperature states both on and off the principle Hugoniot and over a wide range of conditions of direct relevance to planetary interiors. Such studies necessitate reliable temperature measurements below 4000-5000 K. Such relatively low temperature states are also of particular interest for materials such as methane and water that do not experience much heating under shock compression. In order to measure these temperatures as a function of time across the sample, a four-color, near-infrared pyrometry system is being developed for use at the Janus laser facility (LLNL) with channels at wavelengths of 932nm-1008nm, 1008nm-1108nm, 1108nm-1208nm, and 1208nm-1300nm. Each color band is fiber-coupled to an InGaAs PIN photodiode with a rise time of less than 60 ps, read using an 18 GHz oscilloscope in order to ensure time resolutions of under 200 ps. This will allow for high temporal resolution measurements of laser-driven shock compression experiments with total durations of 5-15 ns as well as correlation with simultaneous time-resolved velocity interferometry and visual-wavelength pyrometry. Calibration of the system is being accomplished using quartz targets, as the EOS for quartz is well known, along with a calibrated integrating sphere of known spectral radiance.

  9. Final report on key comparison CCAUV.A-K5: pressure calibration of laboratory standard microphones in the frequency range 2 Hz to 10 kHz

    Science.gov (United States)

    Avison, Janine; Barham, Richard

    2014-01-01

    This document and the accompanying spreadsheets constitute the final report for key comparison CCAUV.A-K5 on the pressure calibration of laboratory standard microphones in the frequency range from 2 Hz to 10 kHz. Twelve national measurement institutes took part in the key comparison and the National Physical Laboratory piloted the project. Two laboratory standard microphones IEC type LS1P were circulated to the participants and results in the form of regular calibration certificates were collected throughout the project. One of the microphones was subsequently deemed to have compromised stability for the purpose of deriving a reference value. Consequently the key comparison reference value (KCRV) has been made based on the weighted mean results for sensitivity level and for sensitivity phase from just one of the microphones. Corresponding degrees of equivalence (DoEs) have also been calculated and are presented. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. Space and time structure of helium pulsed surface-wave discharges at intermediate pressures (5-50 Torr)

    Science.gov (United States)

    Hamdan, Ahmad; Valade, Fabrice; Margot, Joëlle; Vidal, François; Matte, Jean-Pierre

    2017-01-01

    In this paper, the ignition and development of a plasma created by pulsed surface wave discharges (PSWDs) was experimentally investigated using time-resolved imaging techniques and optical spectroscopy in helium at intermediate gas pressures between 5 and 50 Torr. We found that the ionization front moves at a few km s-1 during the ignition phase and decreases to hundreds of m s-1 after only some tens of µs. Once the plasma has reached a sufficient length, a standing wave pattern is observed in the light emission of the discharge. We attribute its formation to the reflection of the surface wave on the ionization front, which results in a pattern of nodes and antinodes. We have also determined the time and space evolution of the gas temperature. It is shown that the gas temperature increases from the room temperature value to a plateau at several hundreds of degrees over a short time (typically 100 µs). These results supports those obtained by light emission imaging and also show that the standing wave pattern does not affect the gas temperature.

  11. Influence of pulsed nanosecond volume discharge in atmospheric-pressure air on the electrical characteristics of MCT epitaxial films

    Science.gov (United States)

    Grigoryev, Denis V.; Voitsekhovskii, Alexandr V.; Lozovoy, Kirill A.; Nesmelov, Sergey N.; Dzyadukh, Stanislav M.; Tarasenko, Viktor F.; Shulepov, Michail A.; Dvoretskii, Sergei A.

    2015-12-01

    The purpose of this paper was investigating the effect of volume nanosecond discharge in air at atmospheric pressure on the electro-physical properties of the HgCdTe (MCT) epitaxial films grown by molecular beam epitaxy. Hall measurements of electro-physical parameters of MCT samples after irradiation have shown that there is a layer of epitaxial films exhibiting n-type conductivity that is formed in the near-surface area. After more than 600 pulses of influence parameters and thickness of the resulting n-layer is such that the measured field dependence of Hall coefficient corresponds to the material of n-type conductivity. Also it is shown that the impact of the discharge leads to significant changes in electro-physical characteristics of MIS structures. This fact is demonstrated by increase in density of positive fixed charge, change in the hysteresis type of the capacitance-voltage characteristic, an increase in density of surface states. The preliminary results show that it is possible to use such actions in the development of technologies of the controlled change in the properties of MCT.

  12. Influence of Pulse Pressure on the State of Biopolymers and the Probability of Hydrolysis of Starch in Seeds

    Directory of Open Access Journals (Sweden)

    Violetta Pavlova

    2013-09-01

    Full Text Available Damage of seeds which leads to destruction of the crystal lattice and the phase transition of polymers is formed under the pulse pressure (PP treatment. Biopolymers such as starch compressed under specific conditions can be changed from crystalline to a glassy state; this transition is known to extend the life of seeds. The aging of seeds is involved in the enzymatic glycosylation of proteins and nucleic acids. Reducing sugars which have been produced in seeds by non-enzymatic hydrolysis enter into reaction of glycosylation with proteins and amino acids actively. The authors studied the water absorption by seeds of buckwheat (Fagopyrum esculentum Moench., cultivar Saulyk treated by PP. The values of PP which were used to treat had an influence on water absorption during the first hours of imbibition. When water content was 60%, hydrolysis of reserve substances could begin, so water potential was created by osmotically active molecules. Gibbs energy calculation by method of groups’ contribution indicated the reduction in probability of starch hydrolysis in plant seeds during transition from the crystalline to the glassy state.

  13. FAST TRACK COMMUNICATION: Contrasting characteristics of sub-microsecond pulsed atmospheric air and atmospheric pressure helium-oxygen glow discharges

    Science.gov (United States)

    Walsh, J. L.; Liu, D. X.; Iza, F.; Rong, M. Z.; Kong, M. G.

    2010-01-01

    Glow discharges in air are often considered to be the ultimate low-temperature atmospheric pressure plasmas for numerous chamber-free applications. This is due to the ubiquitous presence of air and the perceived abundance of reactive oxygen and nitrogen species in air plasmas. In this paper, sub-microsecond pulsed atmospheric air plasmas are shown to produce a low concentration of excited oxygen atoms but an abundance of excited nitrogen species, UV photons and ozone molecules. This contrasts sharply with the efficient production of excited oxygen atoms in comparable helium-oxygen discharges. Relevant reaction chemistry analysed with a global model suggests that collisional excitation of O2 by helium metastables is significantly more efficient than electron dissociative excitation of O2, electron excitation of O and ion-ion recombination. These results suggest different practical uses of the two oxygen-containing atmospheric discharges, with air plasmas being well suited for nitrogen and UV based chemistry and He-O2 plasmas for excited atomic oxygen based chemistry.

  14. Consumer perception of the use of high-pressure processing and pulsed electric field technologies in food production.

    Science.gov (United States)

    Nielsen, Henriette Boel; Sonne, Anne-Mette; Grunert, Klaus G; Banati, Diana; Pollák-Tóth, Annamária; Lakner, Zoltán; Olsen, Nina Veflen; Zontar, Tanja Pajk; Peterman, Marjana

    2009-02-01

    The success of new food processing technologies is highly dependent on consumers' acceptance. The purpose of this paper is to study consumers' perceptions of two new processing technologies and food products produced by means of these novel technologies. To accomplish this, a qualitative study on consumer attitudes towards high-pressure processing (HPP) and pulsed electric field (PEF) processing of food was carried out. In all 97 adults between 20 and 71 years of age participated in 12 focus groups conducted in Slovenia, Hungary, Serbia, Slovakia, Norway and Denmark using a common guideline. Participants were introduced to the HPP and PEF technologies and then to the effect of the two new technologies on two specific product categories: juice and baby food. The transcribed data was content analysed and the coded data was transformed into diagrams using UCINET 5 and NETDRAW. The results show that consumers perceived the main advantages of HPP and PEF products to be the products' naturalness, improved taste and their high nutritional value, whereas the main disadvantage was the lack of information about the PEF and HPP products. The results of the participants' evaluation of the PEF and HPP processes showed that environmental friendliness and the more natural products were seen as the main advantages, while they were concerned about body and health, the higher price of the products, the lack of information about the technologies and a general scepticism. The study also shows that North European participants were a bit more sceptical towards PEF and HPP products than the East European participants.

  15. Modeling seismic stimulation: Enhanced non-aqueous fluid extraction from saturated porous media under pore-pressure pulsing at low frequencies

    Science.gov (United States)

    Lo, Wei-Cheng; Sposito, Garrison; Huang, Yu-Han

    2012-03-01

    Seismic stimulation, the application of low-frequency stress-pulsing to the boundary of a porous medium containing water and a non-aqueous fluid to enhance the removal of the latter, shows great promise for both contaminated groundwater remediation and enhanced oil recovery, but theory to elucidate the underlying mechanisms lag significantly behind the progress achieved in experimental research. We address this conceptual lacuna by formulating a boundary-value problem to describe pore-pressure pulsing at seismic frequencies that is based on the continuum theory of poroelasticity for an elastic porous medium permeated by two immiscible fluids. An exact analytical solution is presented that is applied numerically using elasticity parameters and hydraulic data relevant to recent proof-of-principle laboratory experiments investigating the stimulation-induced mobilization of trichloroethene (TCE) in water flowing through a compressed sand core. The numerical results indicated that significant stimulation-induced increases of the TCE concentration in effluent can be expected from pore-pressure pulsing in the frequency range of 25-100 Hz, which is in good agreement with what was observed in the laboratory experiments. Sensitivity analysis of our numerical results revealed that the TCE concentration in the effluent increases with the porous medium framework compressibility and the pulsing pressure. Increasing compressibility also leads to an optimal stimulation response at lower frequencies, whereas changing the pulsing pressure does not affect the optimal stimulation frequency. Within the context of our model, the dominant physical cause for enhancement of non-aqueous fluid mobility by seismic stimulation is the dilatory motion of the porous medium in which the solid and fluid phases undergo opposite displacements, resulting in stress-induced changes of the pore volume.

  16. Experimental study on the pressure and pulse wave propagation in viscoelastic vessel tubes-effects of liquid viscosity and tube stiffness.

    Science.gov (United States)

    Ikenaga, Yuki; Nishi, Shohei; Komagata, Yuka; Saito, Masashi; Lagrée, Pierre-Yves; Asada, Takaaki; Matsukawa, Mami

    2013-11-01

    A pulse wave is the displacement wave which arises because of ejection of blood from the heart and reflection at vascular bed and distal point. The investigation of pressure waves leads to understanding the propagation characteristics of a pulse wave. To investigate the pulse wave behavior, an experimental study was performed using an artificial polymer tube and viscous liquid. A polyurethane tube and glycerin solution were used to simulate a blood vessel and blood, respectively. In the case of the 40 wt% glycerin solution, which corresponds to the viscosity of ordinary blood, the attenuation coefficient of a pressure wave in the tube decreased from 4.3 to 1.6 dB/m because of the tube stiffness (Young's modulus: 60 to 200 kPa). When the viscosity of liquid increased from approximately 4 to 10 mPa·s (the range of human blood viscosity) in the stiff tube, the attenuation coefficient of the pressure wave changed from 1.6 to 3.2 dB/m. The hardening of the blood vessel caused by aging and the increase of blood viscosity caused by illness possibly have opposite effects on the intravascular pressure wave. The effect of the viscosity of a liquid on the amplitude of a pressure wave was then considered using a phantom simulating human blood vessels. As a result, in the typical range of blood viscosity, the amplitude ratio of the waves obtained by the experiments with water and glycerin solution became 1:0.83. In comparison with clinical data, this value is much smaller than that seen from blood vessel hardening. Thus, it can be concluded that the blood viscosity seldom affects the attenuation of a pulse wave.

  17. Statistical Investigations on Solar Wind Dynamic Pressure Pulses:Basic features and Their Impacts on Geosynchronous Magnetic Fields

    Science.gov (United States)

    Zuo, Pingbing; Feng, Xueshang

    2016-07-01

    Solar wind dynamic pressure pulse (DPP) structures, across which the dynamic pressure abruptly changes over timescales from a few seconds to several minutes, are often observed in the near-Earth space environment. Recently we have developed a novel procedure that is able to rapidly identify the DPPs from the plasma data stream, and simultaneously define the transition region and smartly select the upstream and downstream region for analysis. The plasma data with high time-resolution from 3DP instrument on board the WIND spacecraft are inspected with this automatic DPP-searching code, and a complete list of solar wind DPPs of historic WIND observations are built up. We perform a statistical survey on the properties of DPPs near 1 AU based on this event list. It is found that overwhelming majority of DPPs are associated with the solar wind disturbances including the CME-related flows, the corotating interaction regions, as well as the complex ejecta. The annual variations of the averaged occurrence rate of DPPs are roughly in phase with the solar activities. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears no systematic investigations on the response of GMFs to negative DPPs. Here we also study the decompression/compression effects of very strong negative/positive DPPs on GMFs under northward IMFs. In response to the decompression of strong negative DPPs, GMFs on dayside, near the dawn and dusk on nightside are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of events when GOES is located at the midnight sector, GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that on certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Statistically, both the decompression effect of

  18. Nanoscale multilayered and porous carbide interphases prepared by pressure-pulsed reactive chemical vapor deposition for ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Jacques, S., E-mail: jacques@lcts.u-bordeaux1.fr [LCTS, University of Bordeaux 1, CNRS, Herakles-Safran, CEA, 3 allee de la Boetie, F-33600 Pessac (France); Jouanny, I.; Ledain, O.; Maillé, L.; Weisbecker, P. [LCTS, University of Bordeaux 1, CNRS, Herakles-Safran, CEA, 3 allee de la Boetie, F-33600 Pessac (France)

    2013-06-15

    In Ceramic Matrix Composites (CMCs) reinforced by continuous fibers, a good toughness is achieved by adding a thin film called “interphase” between the fiber and the brittle matrix, which acts as a mechanical fuse by deflecting the matrix cracks. Pyrocarbon (PyC), with or without carbide sub-layers, is typically the material of choice to fulfill this role. The aim of this work was to study PyC-free nanoscale multilayered carbide coatings as interphases for CMCs. Nanoscale multilayered (SiC–TiC){sub n} interphases were deposited by pressure-Pulsed Chemical Vapor Deposition (P-CVD) on single filament Hi-Nicalon fibers and embedded in a SiC matrix sheath. The thicknesses of the carbide interphase sub-layers could be made as low as a few nanometers as evidenced by scanning and transmission electron microscopy. By using the P-ReactiveCVD method (P-RCVD), in which the TiC growth involves consumption of SiC, it was not only possible to obtain multilayered (SiC–TiC){sub n} films but also TiC films with a porous multilayered microstructure as a result of the Kirkendall effect. The porosity in the TiC sequences was found to be enhanced when some PyC was added to SiC prior to total RCVD consumption. Because the porosity volume fraction was still not high enough, the role of mechanical fuse of the interphases could not be evidenced from the tensile curves, which remained fully linear even when chemical attack of the fiber surface was avoided.

  19. Pulse Arrival Time Based Cuff-Less and 24-H Wearable Blood Pressure Monitoring and its Diagnostic Value in Hypertension.

    Science.gov (United States)

    Zheng, Yali; Poon, Carmen C Y; Yan, Bryan P; Lau, James Y W

    2016-09-01

    Ambulatory blood pressure monitoring (ABPM) has become an essential tool in the diagnosis and management of hypertension. Current standard ABPM devices use an oscillometric cuff-based method which can cause physical discomfort to the patients with repeated inflations and deflations, especially during nighttime leading to sleep disturbance. The ability to measure ambulatory BP accurately and comfortably without a cuff would be attractive. This study validated the accuracy of a cuff-less approach for ABPM using pulse arrival time (PAT) measurements on both healthy and hypertensive subjects for potential use in hypertensive management, which is the first of its kind. The wearable cuff-less device was evaluated against a standard cuff-based device on 24 subjects of which 15 have known hypertension. BP measurements were taken from each subject over a 24-h period by the cuff-less and cuff-based devices every 15 to 30 minutes during daily activities. Mean BP of each subject during daytime, nighttime and over 24-h were calculated. Agreement between mean nighttime systolic BP (SBP) and diastolic (DBP) measured by the two devices evaluated using Bland-Altman plot were -1.4 ± 6.6 and 0.4 ± 6.7 mmHg, respectively. Receiver operator characteristics (ROC) statistics was used to assess the diagnostic accuracy of the cuff-less approach in the detection of BP above the hypertension threshold during nighttime (>120/70 mmHg). The area under ROC curves were 0.975/0.79 for nighttime. The results suggest that PAT-based approach is accurate and promising for ABPM without the issue of sleep disturbances associated with cuff-based devices.

  20. Amlodipine+benazepril is superior to hydrochlorothiazide+benazepril irrespective of baseline pulse pressure: subanalysis of the ACCOMPLISH trial.

    Science.gov (United States)

    Skoglund, Per H; Svensson, Per; Asp, Joline; Dahlöf, Björn; Kjeldsen, Sverre E; Jamerson, Kenneth A; Weber, Michael A; Jia, Yan; Zappe, Dion H; Östergren, Jan

    2015-02-01

    Pulse pressure (PP) is an independent risk factor for cardiovascular (CV) disease and death but few studies have investigated the effect of antihypertensive treatments in relation to PP levels before treatment. The Avoiding Cardiovascular Events Through Combination Therapy in Patients Living With Systolic Hypertension (ACCOMPLISH) trial showed that the combination of benazepril+amlodipine (B+A) is superior to benazepril+hydrochlorothiazide (B+H) in reducing CV events. We aimed to investigate whether the treatment effects in the ACCOMPLISH trial were dependent on baseline PP. High-risk hypertensive patients (n=11,499) were randomized to double-blinded treatment with single-pill combinations of either B+A or B+H and followed for 36 months. Patients were divided into tertiles according to their baseline PP and events (CV mortality/myocardial infarction or stroke) were compared. Hazard ratios (HRs) for the treatment effect (B+A over B+H) were calculated in a Cox regression model with age, coronary artery disease, and diabetes mellitus as covariates and were compared across the tertiles. The event rate was increased in the high tertile of PP compared with the low tertile (7.2% vs 4.4% P<.01). In the high and medium PP tertiles, HRs were 0.75 (95% confidence interval [CI], 0.60-0.95; P=.018) and 0.74 (CI, 0.56-0.98, P=.034), respectively, in favor of B+A. There was no significant difference between the treatments in the low tertile and no significant differences in treatment effect when comparing the HRs between tertiles of PP. B+A has superior CV protection over B+H in high-risk hypertensive patients independent of baseline PP although the absolute treatment effect is enhanced in the higher tertiles of PP where event rates are higher.

  1. Diagnostics of atmospheric-pressure pulsed-dc discharge with metal and liquid anodes by multiple laser-aided methods

    Science.gov (United States)

    Urabe, Keiichiro; Shirai, Naoki; Tomita, Kentaro; Akiyama, Tsuyoshi; Murakami, Tomoyuki

    2016-08-01

    The density and temperature of electrons and key heavy particles were measured in an atmospheric-pressure pulsed-dc helium discharge plasma with a nitrogen molecular impurity generated using system with a liquid or metal anode and a metal cathode. To obtain these parameters, we conducted experiments using several laser-aided methods: Thomson scattering spectroscopy to obtain the spatial profiles of electron density and temperature, Raman scattering spectroscopy to obtain the neutral molecular nitrogen rotational temperature, phase-modulated dispersion interferometry to determine the temporal variation of the electron density, and time-resolved laser absorption spectroscopy to analyze the temporal variation of the helium metastable atom density. The electron density and temperature measured by Thomson scattering varied from 2.4  ×  1014 cm-3 and 1.8 eV at the center of the discharge to 0.8  ×  1014 cm-3 and 1.5 eV near the outer edge of the plasma in the case of the metal anode, respectively. The electron density obtained with the liquid anode was approximately 20% smaller than that obtained with the metal anode, while the electron temperature was not significantly affected by the anode material. The molecular nitrogen rotational temperatures were 1200 K with the metal anode and 1650 K with the liquid anode at the outer edge of the plasma column. The density of helium metastable atoms decreased by a factor of two when using the liquid anode.

  2. Method of optical self-mixing for pulse wave transit time in comparison with other methods and correlation with blood pressure

    Science.gov (United States)

    Meigas, Kalju; Lass, Jaanus; Kattai, Rain; Karai, Deniss; Kaik, Juri

    2004-07-01

    This paper is a part of research to develop convenient method for continuous monitoring of arterial blood pressure by non-invasive and non-oscillometric way. A simple optical method, using self-mixing in a diode laser, is used for detection of skin surface vibrations near the artery. These vibrations, which can reveal the pulsate propagation of blood pressure waves along the vasculature, are used for pulse wave registration. The registration of the Pulse Wave Transit Time (PWTT) is based on computing the time delay in different regions of the human body using an ECG as a reference signal. In this study, the comparison of method of optical self-mixing with other methods as photoplethysmographic (PPG) and bioimpedance (BI) for PWTT is done. Also correlation of PWTT, obtained with different methods, with arterial blood pressure is calculated. In our study, we used a group of volunteers (34 persons) who made the bicycle exercise test. The test consisted of cycling sessions of increasing workloads during which the HR changed from 60 to 180 beats per minute. In addition, a blood pressure (NIBP) was registered with standard sphygmomanometer once per minute during the test and all NIBP measurement values were synchronized to other signals to find exact time moments where the systolic blood pressure was detected (Korotkoff sounds starting point). Computer later interpolated the blood pressure signal in order to get individual value for every heart cycle. The other signals were measured continuously during all tests. At the end of every session, a recovery period was included until person's NIBP and heart rate (HR) normalized. As a result of our study it turned out that time intervals that were calculated from plethysmographic (PPG) waveforms were in the best correlation with systolic blood pressure. The diastolic pressure does not correlate with any of the parameters representing PWTT. The pulse wave signals measured by laser and piezoelectric transducer are very similar

  3. Effect of steaming, blanching, and high temperature/high pressure processing on the amino Acid contents of commonly consumed korean vegetables and pulses.

    Science.gov (United States)

    Kim, Su-Yeon; Kim, Bo-Min; Kim, Jung-Bong; Shanmugavelan, Poovan; Kim, Heon-Woong; Kim, So-Young; Kim, Se-Na; Cho, Young-Sook; Choi, Han-Seok; Park, Ki-Moon

    2014-09-01

    In the present report, the effects of blanching, steaming, and high temperature/high pressure processing (HTHP) on the amino acid contents of commonly consumed Korean root vegetables, leaf vegetables, and pulses were evaluated using an Automatic Amino Acid Analyzer. The total amino acid content of the samples tested was between 3.38 g/100 g dry weight (DW) and 21.32 g/100 g DW in raw vegetables and between 29.36 g/100 g DW and 30.55 g/100 g DW in raw pulses. With HTHP, we observed significant decreases in the lysine and arginine contents of vegetables and the lysine, arginine, and cysteine contents of pulses. Moreover, the amino acid contents of blanched vegetables and steamed pulses were more similar than the amino acid contents of the HTHP vegetables and HTHP pulses. Interestingly, lysine, arginine, and cysteine were more sensitive to HTHP than the other amino acids. Partial Least Squares-Discriminate Analyses were also performed to discriminate the clusters and patterns of amino acids.

  4. Absolute atomic oxygen density measurements for nanosecond-pulsed atmospheric-pressure plasma jets using two-photon absorption laser-induced fluorescence spectroscopy

    Science.gov (United States)

    Jiang, C.; Carter, C.

    2014-12-01

    Nanosecond-pulsed plasma jets that are generated under ambient air conditions and free from confinement of electrodes have become of great interest in recent years due to their promising applications in medicine and dentistry. Reactive oxygen species that are generated by nanosecond-pulsed, room-temperature non-equilibrium He-O2 plasma jets among others are believed to play an important role during the bactericidal or sterilization processes. We report here absolute measurements of atomic oxygen density in a 1 mm-diameter He/(1%)O2 plasma jet at atmospheric pressure using two-photon absorption laser-induced fluorescence spectroscopy. Oxygen number density on the order of 1013 cm-3 was obtained in a 150 ns, 6 kV single-pulsed plasma jet for an axial distance up to 5 mm above the device nozzle. Temporally resolved O density measurements showed that there are two maxima, separated in time by 60-70 µs, and a total pulse duration of 260-300 µs. Electrostatic modeling indicated that there are high-electric-field regions near the nozzle exit that may be responsible for the observed temporal behavior of the O production. Both the field-distribution-based estimation of the time interval for the O number density profile and a pulse-energy-dependence study confirmed that electric-field-dependent, direct and indirect electron-induced processes play important roles for O production.

  5. Oxygen partial pressure induced effects on the microstructure and the luminescence properties of pulsed laser deposited TiO2 thin films

    Directory of Open Access Journals (Sweden)

    A. K. Kunti

    2017-01-01

    Full Text Available In this work, the influence of oxygen partial pressure on structural, morphological, and optical properties of TiO2 thin films grown on fused quartz substrate at different oxygen partial pressure by pulsed laser deposition were examined. X-Ray diffraction (XRD patterns show the formation of TiO2 anatase phase deposited at high oxygen pressure. Atomic Force Microscopy (AFM reveals that surface roughness of the films increases with oxygen pressure. Variation of surface morphology of films with increasing oxygen partial pressure was studied by AFM. It is observed that energy band gap of the films increases from 3.27 eV to 3.52 eV with the increase of oxygen pressure and is attributed to the decrease of oxygen defects. TiO2 thin films exhibited blue emission under the excitation of 320 nm wavelength. De-convoluted photoluminescence (PL peaks showed that defect states are responsible for visible emission in TiO2 thin films. The intensity of PL emission associated with oxygen vacancies decreases with increasing oxygen pressure. Photometric characteristic analysis shows that the films deposited 1x10-4 mbar oxygen pressure exhibited intense blue emission with high luminescence efficacy of radiation.

  6. 成都地区中老年居民脉压及脉压指数分析%AN ANALYSIS OF PULSE PRESSURE AND PULSE PRESSURE INDEX AMONG MIDDLE-AGED RESIDENTS IN CHENGDU

    Institute of Scientific and Technical Information of China (English)

    吴凯; 高音; 陈晓平; 李龙兴; 万里艳; 陈小妮

    2011-01-01

    [目的]调查分析成都地区中老年居民脉压(PP)、脉压指数(PPI)的影响因素,寻找可能改善脉压异常的方法.[方法]利用2007代谢综合征研究调查资料(共1061人),把人群依据PP(PP≤60 mmHg及PP>60mmHg)及PPI(PPI≤0.450及PPI>0.450)分为正常组及增高组,分析两组人群多代谢异常及心血管疾病危险因素分布特征,并采用Logistic回归分析寻找与PP/PPI相关的危险因素.[结果]①两个分组间年龄、收缩压、男性比重、高血压家族史、体重指教、腰围、臀围、空腹血耱、肾功能等指标PP、PPI增高组明显高于PP、PPI正常组,舒张压则是PP、PPI增高组明显低予PP、PPI正常组.②血脂各成分PP组间无统计学差异,总胆固醇、低密度脂蛋白水平PPI增高组高于正常组.③PP及PPI增高组其代谢综合征、高血压、糖尿病、肥胖、腹型肥胖、血脂异常等患病率皆高于PPI正常组,差异有统计学意义.④Logistic回归分析提示PP、PPI与女性性别、年龄、收缩压、BMI、腰围、臀围、空腹血糖、肌酐、尿酸、总胆固醇、低密度脂蛋白水平呈正相关,与男性性别及舒张压呈负相关.[结论]成都地区脉压及脉压指教与代谢性指标关系密切,可能可以通过改善血脂、空腹血糖、腰围、体重指数、肾功能等指标来减少脉压及脉压指数的异常.%[Objective] To evaluate the influencing factors on pulse pressure (PP) and pulse presure index (PPI) among middle-aged residents in Chengdu, and search the possible methods to relieve PP disorder. [Methods] We divided the 1061 middle-aged people who came from the survey for metabolic syndrome study into 2 groups according to PP (PP≤60mmHg and PP > 60mmHg) and PPI (PPI (PPI≤0.450 and PPI > 0.450)). They were normal PP/PPI group and augmented PP/PPI group. The normal PP group mean the PP of the people was less than or equal to 60 mmHg, and normal PPI group was PPI less or equal to 0.450. The

  7. 指针式压力表自动检定系统的设计与实现%Design and implementation of fully automatic calibration system for pressure gauges with pointers

    Institute of Scientific and Technical Information of China (English)

    熊伟丽; 周寰; 徐保国

    2009-01-01

    A fully automatic calibration system for pressure gauges with pointers is presented, including a calibration management system of pressure gauges and an automatic reading system of pointer readings. The operation is very convenient with the use of visual interface in this system. The operator only needs to input several necessary coefficients such as range, accuracy and so on, the pointer reading of pressure gauges will be read automatically. The automatic reading method will be used to calibrate for almost all kinds of pointer gauges. The accuracy is decided by resolution and processing time. This automatic calibration system improves the present state of pressure calibration, and enhances the automation level of calibration to some extent.%设计并开发了一种指针式压力表自动检定系统.该系统包括压力表检定/校准管理系统和仪表示值自动判读系统两部分.系统的可视化界面使得操作非常简单,操作人员只需输入量程、精度等必要参数,压力表的指针读数即可自动读出.给出的自动判读方法可用于各种指针式仪表精度的自动检测、判读,其精度取决于图像的分辨率和限定的处理时间.本系统可较大地改善压力表人工检定工作的落后状况,在一定程度上提高了检定工作的自动化水平和检定结果的稳定性.

  8. X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Cheng; Shao Tao; Ren Chengyan; Zhang Dongdong [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Tarasenko, Victor; Kostyrya, Igor D. [Institute of High Current Electronics, Russian Academy of Science, Tomsk 634055 (Russian Federation); Ma Hao [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Yan Ping [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2012-12-15

    This paper describes experimental studies of the dependence of the X-ray intensity on the anode material in nanosecond high-voltage discharges. The discharges were generated by two nanosecond-pulse generators in atmospheric air with a highly inhomogeneous electric field by a tube-plate gap. The output pulse of the first generator (repetitive pulse generator) has a rise time of about 15 ns and a full width at half maximum of 30-40 ns. The output of the second generator (single pulse generator) has a rise time of about 0.3 ns and a full width at half maximum of 1 ns. The electrical characteristics and the X-ray emission of nanosecond-pulse discharge in atmospheric air are studied by the measurement of voltage-current waveforms, discharge images, X-ray count and dose. Our experimental results showed that the anode material rarely affects electrical characteristics, but it can significantly affect the X-ray density. Comparing the density of X-rays, it was shown that the highest x-rays density occurred in the diffuse discharge in repetitive pulse mode, then the spark discharge with a small air gap, and then the corona discharge with a large air gap, in which the X-ray density was the lowest. Therefore, it could be confirmed that the bremsstrahlung at the anode contributes to the X-ray emission from nanosecond-pulse discharges.

  9. Time-resolved OES of nanosecond pulsed discharges in N$_{2}$ and N$_{2}$/H$_{2}$O mixtures]{Time-resolved optical emission spectroscopy of nanosecond pulsed discharges in atmospheric pressure N$_{2}$ and N$_{2}$/H$_{2}$O mixtures

    CERN Document Server

    van der Horst, R M; van Veldhuizen, E M; Bruggeman, P J

    2014-01-01

    In this contribution, nanosecond pulsed discharges in N$_{2}$ and N$_{2}$/0.9% H$_{2}$O at atmospheric pressure (at 300 K) are studied with time-resolved imaging, optical emission spectroscopy and Rayleigh scattering. A 170 ns high voltage pulse is applied across two pin-shaped electrodes at a frequency of 1 kHz. The discharge consists of three phases: an ignition phase, a spark phase and a recombination phase. During the ignition phase the emission is mainly caused by molecular nitrogen (N$_{2}$(C-B)). In the spark and recombination phase mainly atomic nitrogen emission is observed. The emission when H$_{2}$O is added is very similar, except the small contribution of H$_{\\alpha}$ and the intensity of the molecular N$_{2}$(C-B) emission is less.

  10. Experimental and numerical investigations of air plasmas induced by multi-MeV pulsed X-ray from low to atmospheric pressures

    Science.gov (United States)

    Maulois, Mélissa; Ribière, Maxime; Eichwald, Olivier; Yousfi, Mohammed; Pouzalgues, Romain; Garrigues, Alain; Delbos, Christophe; Azaïs, Bruno

    2016-09-01

    This research work is devoted to the experimental and theoretical analysis of air plasmas induced by multi-MeV pulsed X-ray for a large pressure range of humid air background gas varying from 20 mbar to atmospheric pressure. The time evolution of the electron density of the air plasma is determined by electromagnetic wave absorption measurements. The measurements have uncertainties of about ±30%, taking into account the precision of the dose measurement and also the shot to shot fluctuations of the generator. The experimental electron density is obtained by comparing the measurements of the transmitted microwave signals to the calculated ones. The calculations need the knowledge of the time evolution of the electron mean energy, which is determined by a chemical kinetic model based on a reaction scheme involving 39 species interacting following 265 reactions. During the X-ray pulse, a good agreement is obtained between time evolution of the electron density obtained from absorption measurements and calculations based on the kinetic model. The relative deviation on the maximum electron density and the corresponding plasma frequency is always lower than 10%. The maximum electron density varies from 4 × 1011 to 3.5 × 1013 cm-3 between 30 mbar to atmospheric pressure, while the peak of the electron mean energy decreases from 5.64 eV to 4.27 eV in the same pressure range.

  11. Automated calibration of multistatic arrays

    Energy Technology Data Exchange (ETDEWEB)

    Henderer, Bruce

    2017-03-14

    A method is disclosed for calibrating a multistatic array having a plurality of transmitter and receiver pairs spaced from one another along a predetermined path and relative to a plurality of bin locations, and further being spaced at a fixed distance from a stationary calibration implement. A clock reference pulse may be generated, and each of the transmitters and receivers of each said transmitter/receiver pair turned on at a monotonically increasing time delay interval relative to the clock reference pulse. Ones of the transmitters and receivers may be used such that a previously calibrated transmitter or receiver of a given one of the transmitter/receiver pairs is paired with a subsequently un-calibrated one of the transmitters or receivers of an immediately subsequently positioned transmitter/receiver pair, to calibrate the transmitter or receiver of the immediately subsequent transmitter/receiver pair.

  12. HAWC Timing Calibration

    CERN Document Server

    Huentemeyer, Petra; Dingus, Brenda

    2009-01-01

    The High-Altitude Water Cherenkov (HAWC) Experiment is a second-generation highsensitivity gamma-ray and cosmic-ray detector that builds on the experience and technology of the Milagro observatory. Like Milagro, HAWC utilizes the water Cherenkov technique to measure extensive air showers. Instead of a pond filled with water (as in Milagro) an array of closely packed water tanks is used. The event direction will be reconstructed using the times when the PMTs in each tank are triggered. Therefore, the timing calibration will be crucial for reaching an angular resolution as low as 0.25 degrees.We propose to use a laser calibration system, patterned after the calibration system in Milagro. Like Milagro, the HAWC optical calibration system will use ~1 ns laser light pulses. Unlike Milagro, the PMTs are optically isolated and require their own optical fiber calibration. For HAWC the laser light pulses will be directed through a series of optical fan-outs and fibers to illuminate the PMTs in approximately one half o...

  13. Nonlinear interaction of ultraintense laser pulse with relativistic thin plasma foil in the radiation pressure-dominant regime

    Indian Academy of Sciences (India)

    KRISHNA KUMAR SONI; K P MAHESHWARI

    2016-11-01

    We present a study of the effect of laser pulse temporal profile on the energy/momentum acquired by the ions as a result of the ultraintense laser pulse focussed on a thin plasma layer in the radiation pressuredominant(RPD) regime. In the RPD regime, the plasma foil is pushed by ultraintense laser pulse when the radiation cannot propagate through the foil, while the electron and ion layers move together. The nonlinear character of laser–matter interaction is exhibited in the relativistic frequency shift, and also change in the wave amplitude as the EM wave gets reflected by the relativistically moving thin dense plasma layer. Relativistic effects in a highenergy plasma provide matching conditions that make it possible to exchange very effectively ordered kineticenergy and momentum between the EM fields and the plasma. When matter moves at relativistic velocities, the efficiency of the energy transfer from the radiation to thin plasma foil is more than 30% and in ultrarelativisticcase it approaches one. The momentum/energy transfer to the ions is found to depend on the temporal profile of the laser pulse. Our numerical results show that for the same laser and plasma parameters, a Lorentzian pulse canaccelerate ions upto 0.2 GeV within 10 fs which is 1.5 times larger than that a Gaussian pulse can.

  14. Effects of temperature and pressure on the structural and optical properties of ZnO films grown by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    ZnO thin films were deposited on fused silica via pulsed laser deposition (PLD) at substrate temperatures from 300°C to 800°C and ambient oxygen pressures ranging from 10-2 mTorr to 240 mTorr. X-ray diffraction (XRD) and Raman spectra indicated that wurtzite ZnO was obtained in all cases. The highly c-oriented ZnO films were obtained for oxygen pressures above 11 mTorr. The room-temperature photoluminescence (PL) spectra demonstrated that all the films exhibited strong near-band-edge (NBE) emission, while deep-level (DL) emission was also observed in films deposited at oxygen pressures below 80 mTorr. From analysis of the XRD, Raman and photoluminescence PL data, an optimal condition was identified for the deposition of highly crystallized ZnO films.

  15. Influence of oxygen pressure and aging on LaAlO3 films grown by pulsed laser deposition on SrTiO3 substrates

    KAUST Repository

    Park, Jihwey

    2014-02-24

    The crystal structures of LaAlO3 films grown by pulsed laser deposition on SrTiO3 substrates at oxygen pressure of 10−3 millibars or 10−5 millibars, where kinetics of ablated species hardly depend on oxygen background pressure, are compared. Our results show that the interface between LaAlO3 and SrTiO3 is sharper when the oxygen pressure is lower. Over time, the formation of various crystalline phases is observed while the crystalline thickness of the LaAlO3 layer remains unchanged. X-ray scattering as well as atomic force microscopy measurements indicate three-dimensional growth of such phases, which appear to be fed from an amorphous capping layer present in as-grown samples.

  16. 压阻式压力传感器样本集自校正及其计算方法%Self-calibration and algorithm of sample set of piezoresistive pressure sensors

    Institute of Scientific and Technical Information of China (English)

    黄晓因; 晋芳伟; 周平

    2007-01-01

    Aiming at piezoresistive pressure sensors, this paper studies simulation of standard pressure by using benchmark current source and self-calibration of the sampling data characteristics. A data fusion algorithm for sample set is presented which transforms a surface problem into a curve fitting and interpolation problem. The simulation result shows that benchmark current source simulating pressure is successful and data fusion algorithm is effective. The maximum measurement error is only 0.098 kPa and maximum relative error is 0.92% at 0-45 kPa and -10-45℃.

  17. Calibration uncertainty

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Anglov, Thomas

    2002-01-01

    Methods recommended by the International Standardization Organisation and Eurachem are not satisfactory for the correct estimation of calibration uncertainty. A novel approach is introduced and tested on actual calibration data for the determination of Pb by ICP-AES. The improved calibration unce...

  18. Run-to-run variations, asymmetric pulses, and long time-scale transient phenomena in dielectric-barrier atmospheric pressure glow discharges

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jichul; Raja, Laxminarayan L [Department of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, TX 78712 (United States)

    2007-05-21

    The dielectric-barrier (DB) discharge is an important approach to generate uniform non-equilibrium atmospheric-pressure glow discharges. We report run-to-run variations, asymmetric pulse formation and long time-scale transient phenomena in these discharges. For similar DB discharge geometric and operating conditions, we observe significant run-to-run variations as manifested in the different voltage-current waveforms at the start of each new run. These run-to-run variations are also accompanied by asymmetric pulses at the start of each run. The variations are observed to drift to a repeatable true steady-state condition on time scales of order tens of minutes to hours. Asymmetric pulse waveforms drift to a symmetric pulse waveform at the true steady state. We explore reasons for these phenomena and rule out thermal drift during a discharge run and gas-phase impurity buildup as potential causes. The most plausible explanation appears to be variations in the surface characteristics of the DBs between two consecutive runs owing to varying inter-run environmental exposure and the conditioning of the dielectric surface during a run owing to plasma-surface interactions. We speculate that the dielectric surface state affects the secondary electron emission coefficient of the surface which in turn is manifested in the discharge properties. A zero-dimensional model of the discharge is used to explore the effect of secondary electron emission.

  19. Dependence of macrophage superoxide release on the pulse amplitude of an applied pressure regime: a potential factor at the soft tissue-implant interface.

    Science.gov (United States)

    Shin, Hainsworth Y; Frechette, Danielle M; Rohner, Nathan; Zhang, Xiaoyan; Puleo, David A; Bjursten, Lars M

    2016-03-01

    Failure of soft tissue implants has been largely attributed to the influence of biomaterial surface properties on the foreign body response, but some implant complications, e.g. macrophage accumulation and necrosis, are still not effectively addressed with surface treatments to minimize deleterious biomaterial effects. We explored an alternative explanation for implant failure, linking biocompatibility with implant micromotion-induced pressure fluctuations at the tissue-biomaterial interface. For this purpose, we used a custom in vitro system to characterize the effects of pressure fluctuations on the activity of macrophages, the predominant cells at a healing implant site. Initially, we quantified superoxide production by HL60-derived macrophage-like cells under several different pressure regimes with means of 5-40 mmHg, amplitudes of 0-15 mmHg and frequencies of 0-1.5 Hz. All pressure regimes tested elicited significantly (p superoxide production by macrophage-like cells relative to parallel controls. Notably, pressure-sensitive reductions in superoxide release correlated (r(2)  = 0.74; p superoxide production and cell viability, we also explored the influence of cyclic pressure on macrophage numbers and death. Compared to controls, adherent macrophage-like cells exposed to 7.5/2.5 mmHg cyclic pressures for 6 h exhibited significantly (p superoxide dismutase. Collectively, our results suggest that pressure pulses are a putative regulator of macrophage adhesion via a superoxide-related effect. Pressure fluctuations, e.g. due to implant micromotion, may, therefore, potentially modulate macrophage-dependent wound healing.

  20. Ballistic Imaging of High-Pressure Fuel Sprays using Incoherent, Ultra- short Pulsed Illumination with an Ultrafast OKE-based Time Gating

    CERN Document Server

    Purwar, Harsh; Rozé, Claude; Blaisot, Jean-Bernard

    2015-01-01

    We present an optical Kerr effect based time-gate with the collinear incidence of the pump and probe beams at the Kerr medium, liquid carbon disulfide, for ballistic imaging of the high-pressure fuel sprays. The probe pulse used to illuminate the object under study is extracted from the supercontinuum generated by tightly focusing intense femtosecond laser pulses inside water, thereby destroying their coherence. The optical imaging spatial resolution and gate timings are investigated and compared with a similar setup without supercontinuum generation, where the probe is still coherent. And finally, a few ballistic images of the fuel sprays using coherent and incoherent illumination with the proposed time-gate are presented and compared qualitatively.

  1. Numerical simulation of the main characteristics of a high-pressure DF – CO{sub 2} laser for amplification of picosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Agroskin, V Ya; Bravy, B G; Vasiliev, G K; Kashtanov, S A; Makarov, E F; Sotnichenko, S A; Chernyshev, Yu A [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2013-12-31

    The gain characteristics of the medium of a pulsed DF – CO{sub 2} laser in the ten-micron region at the working gas pressures from 1 to 2.5 atm, which were experimentally determined in [4], are numerically simulated using a scheme that includes the main chemical and relaxation processes. It is shown that the chosen scheme of processes makes it possible (i) to numerically describe the experimental data on the temporal behaviour of gains; (ii) to explain the reason for early degradation of gains (at the degree of D{sub 2} transformation of about 20%); (iii) from comparison of experimental and calculated temporal gain profiles, to determine the degree of photodissociation of F{sub 2} molecules, which is an important parameter determining the operation of pulsed chemical DF – CO{sub 2} lasers; and (iv) to predict the gain characteristics of working mixtures depending on their composition and pressure and on the initiation parameters. The predicted gains in the mixtures of the optimal composition at a pressure of 2.5 atm, a degree of dissociation of F{sub 2} molecules per flash ∼1%, and a flash duration at half-width of ∼3 μs are ∼7 m{sup -1}. (lasers)

  2. Theoretical investigation of the variation of the radiation frequency of atmospheric-pressure CO/sub 2/ lasers in the course of a lasing pulse

    Energy Technology Data Exchange (ETDEWEB)

    Kuntsevich, B.F.; Maliuta, D.D.; Mezhevov, V.S.; Napartovich, A.P.; Strel' tsov, A.P.

    1987-02-01

    The variation of the radiation frequency during the emission pulse of atmospheric-pressure CO/sub 2/ lasers is studied for the case where the underlying mechanisms responsible for the frequency sweeping are the variation of the density of free electrons in the discharge and anomalous dispersion. The frequency variation can take on both a monotonic and nonmonotonic character. If the initial position of the resonator's longitudinal mode is fixed, then the frequency range within which the main fraction of the lasing energy luminesces changes with variations of the photon lifetime in the resonator and of the energy stored by the discharge. 17 references.

  3. Characterization of chemical contaminants and their spectral properties from an atmospheric pressure ns-pulsed microdischarge in neon

    Science.gov (United States)

    Sillerud, Colin H.; Schwindt, Peter D. D.; Moorman, Mathew; Yee, B. T.; Anderson, John; Pfeifer, Nathaniel B.; Hedberg, E. L.; Manginell, Ronald P.

    2017-03-01

    Portable applications of microdischarges, such as the remediation of gaseous wastes or the destruction of volatile organic compounds, will mandate operation in the presence of contaminant species. This paper examines the temporal evolution of microdischarge optical and ultraviolet emissions during pulsed operation by experimental methods. By varying the pulse length of a microdischarge initiated in a 4-hole silicon microcavity array operating in a 655 Torr ambient primarily composed of Ne, we were able to measure the emission growth rates for different contaminant species native to the discharge environment as a function of pulse length. It was found that emission from hydrogen and oxygen impurities demonstrated similar rates of change, while emissions from molecular and atomic nitrogen, measured at 337.1 and 120 nm, respectively, exhibited the lowest rate of change. We conclude that it is likely that O2 undergoes the same resonant energy transfer process between rare gas excimers that has been shown for H2. Further, efficient resonant processes were found to be favored during ignition and extinction phases of the pulse, while emission at the 337.1 nm line from N2 was favored during the intermediate stage of the plasma. In addition to the experimental results, a zero-dimensional analysis is also presented to further understand the nature of the microdischarge.

  4. Continuous-Flow Inlet Systems for Low Pressure Curie-Point Pyrolysis. Introduction of Pulse-Pyrolysis

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Carlsen, Lars

    1984-01-01

    With emphasis on a constant reactant flow, a series of inlet systems for gas-phase Curie-point pyrolysis—mass spectrometry experiments have been studied. Inlet systems for the handling of gaseous, liquid and oligomeric (solid) samples have been designed and their performances evaluated. The princ....... The principle of pulse-pyrolysis is introduced and its applicability to kinetic studies outlined....

  5. Simulations of atmospheric pressure discharge in a high-voltage nanosecond pulse using the particle-in-cell Monte Carlo collision model in noble gases

    Science.gov (United States)

    Shi, Feng; Wang, Dezhen; Ren, Chunsheng

    2008-06-01

    Atmospheric pressure discharge nonequilibrium plasmas have been applied to plasma processing with modern technology. Simulations of discharge in pure Ar and pure He gases at one atmospheric pressure by a high voltage trapezoidal nanosecond pulse have been performed using a one-dimensional particle-in-cell Monte Carlo collision (PIC-MCC) model coupled with a renormalization and weighting procedure (mapping algorithm). Numerical results show that the characteristics of discharge in both inert gases are very similar. There exist the effects of local reverse field and double-peak distributions of charged particles' density. The electron and ion energy distribution functions are also observed, and the discharge is concluded in the view of ionization avalanche in number. Furthermore, the independence of total current density is a function of time, but not of position.

  6. Ar/O{sub 2} gas pressure dependence of atomic concentration of zirconia prepared by zirconium pulse arc PBII and D

    Energy Technology Data Exchange (ETDEWEB)

    Yukimura, Ken [Department of Electrical Engineering, Doshisha University, 1-3 Tatara-Miyakodani, Kyotanabe, Kyoto 610-0321 (Japan)]. E-mail: kyukimur@mail.doshisha.ac.jp; Yoshinaga, Hiroaki [Department of Electrical Engineering, Doshisha University, 1-3 Tatara-Miyakodani, Kyotanabe, Kyoto 610-0321 (Japan); Ohtsu, Yasunori [Department of Electrical and Electronic Engineering, Saga University, Honjo-machi1, Saga 840-8502 (Japan); Fujita, Hiroharu [Department of Electrical and Electronic Engineering, Saga University, Honjo-machi1, Saga 840-8502 (Japan); Nakamura, Keiji [Department of Electrical Engineering, College of Engineering, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501 (Japan); Ma Xinxin [School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2006-01-15

    Zirconium oxide films were prepared by plasma-based ion implantation and deposition (PBII and D), where a zirconium pulse arc discharge was generated in O{sub 2}/Ar gas mixture. The plasma was maintained for approximately 3 ms, and the ion current at the substrate was detected in a time range from 1 to 10 ms after the arc initiation. At O{sub 2}/Ar pressures of 2.6-3.0 Pa, a stoichiometric film was obtained, while at a pressure lower than 2.2 Pa, the film also contained ZrO {sub x} (x < 2) phase as well as ZrO{sub 2} phase. In the absence of argon gas, the plasma became unstable, which resulted in shortage of zirconium ions in the plasma, and hence, a stoichiometric condition was not found.

  7. Effect of oxygen partial pressure on structural and optical properties of pulsed laser deposited CaBi4Ti4O15 thin films

    Science.gov (United States)

    Emani, Sivanagi Reddy; Raju, K. C. James

    2017-03-01

    The influence of oxygen partial pressure (OPP) on the structural and optical properties of CaBi4Ti4O15 (CBTi) thin films deposited by pulsed laser deposition have been investigated in the range of 0.1 mbar to 7.8 × 10-3 mbar. The structural properties show all the films are polycystlline in nature with orthorombic structure. The optical transmission of the films is in the range of 60-90%. A slight shift in transmission threshold towards higher wavelength region with an increase in O2 pressure reveals the systematic reduction in the optical band gap energy (3.69 to 3.59 eV) of the films. Raman studies confirm the phase formation and presence of stresses in the films. It is suggested that the OPP played a key role in controlling crystallinity, morphology, chemical composition and optical properties in CBTi thin films.

  8. Design and performance of high-pressure PLANET beamline at pulsed neutron source at J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, T.; Sano-Furukawa, A. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Arima, H. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Komatsu, K. [Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Yamada, A. [University of Shiga Prefecture, Shiga 522-8533 (Japan); Inamura, Y.; Nakatani, T. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Seto, Y. [Graduate School of Science, Kobe University, Kobe 657-8501 (Japan); Nagai, T. [Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Utsumi, W. [Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Iitaka, T. [Computational Astrophysics Laboratory, RIKEN, Saitama 351-0198 (Japan); Kagi, H. [Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Katayama, Y. [Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Inoue, T. [Geodynamic Research Center, Ehime University, Matsuyama 790-8577 (Japan); Otomo, T. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 205-001 (Japan); Suzuya, K. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Kamiyama, T. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 205-001 (Japan); Arai, M. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Yagi, T. [Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan)

    2015-04-21

    PLANET is a time-of-flight (ToF) neutron beamline dedicated to high-pressure and high-temperature experiments. The large six-axis multi-anvil high-pressure press designed for ToF neutron diffraction experiments enables routine data collection at high pressures and high temperatures up to 10 GPa and 2000 K, respectively. To obtain clean data, the beamline is equipped with the incident slits and receiving collimators to eliminate parasitic scattering from the high-pressure cell assembly. The high performance of the diffractometer for the resolution (Δd/d~0.6%) and the accessible d-spacing range (0.2–8.4 Å) together with low-parasitic scattering characteristics enables precise structure determination of crystals and liquids under high pressure and temperature conditions.

  9. Measurement of vibrationally excited N2(v) in an atmospheric-pressure air pulsed corona discharge using coherent anti-Stokes Raman scattering

    Science.gov (United States)

    Teramoto, Yoshiyuki; Ono, Ryo

    2014-08-01

    Vibrationally excited N2(v = 1, 2) in an atmospheric-pressure air pulsed corona discharge was measured using coherent anti-Stokes Raman scattering (CARS). In a dry air discharge, the vibrational temperature determined from the ratio N2(v = 2)/N2(v = 0), Tv2, was approximately 500 K higher than that determined from N2(v = 1)/N2(v = 0), Tv1, immediately after the discharge pulse. Both vibrational temperatures reached equilibrium within 100 μs after the discharge pulse by the vibration-to-vibration (V-V) process of N2-N2. The translational temperature was also measured using CARS. The rise in the translational temperature due to vibration-to-translation (V-T) energy transfer was not observed for a postdischarge time of 5 μs-1 ms in the dry-air discharge. However, when the air was humidified, a significant V-T energy transfer was observed. It was due to an extremely rapid V-T process of H2O-H2O following the V-V process of N2-H2O. Measurements showed that the humidification of the ambient air accelerated the decrease in the N2 vibrational temperature and increased the translational temperature. N2(v) was generated mostly in the secondary streamer, not in the primary one, according to estimation from the measured N2(v) density.

  10. The influence of radiative heat exchange on the character of gasdynamic flows under conditions of pulsed discharge in high-pressure cesium vapor

    Science.gov (United States)

    Baksht, F. G.; Lapshin, V. F.

    2015-01-01

    The gasdynamics of pulse-periodic radiative discharge in high-pressure cesium vapor has been studied in the framework of a two-temperature multifluid model. It is established that, at a limited volume of the gas-discharge tube, the character of gasdynamic flows depends on the conditions of radiative heat exchange in discharge plasma. In cases in which the main contribution to radiative energy losses is related to a spectral region with optical thickness τ R (λ) ˜ 1, there is nonlocal radiative heat exchange in discharge plasma, which is uniformly heated over the entire tube volume and moves from the discharge axis to tube walls during the entire pulse of discharge current. Under the conditions of radiative losses determined by the spectral region where τ R (λ) ≪ 1, the reabsorption of radiation is absent and discharge plasma is nonuniformly heated by the current pulse. This leads to the appearance of reverse motions, so that the heated plasma is partly pushed toward the tube walls and partly returned to the discharge axis.

  11. Effect of modest salt reduction on blood pressure, urinary albumin, and pulse wave velocity in white, black, and Asian mild hypertensives.

    Science.gov (United States)

    He, Feng J; Marciniak, Maciej; Visagie, Elisabeth; Markandu, Nirmala D; Anand, Vidya; Dalton, R Neil; MacGregor, Graham A

    2009-09-01

    A reduction in salt intake lowers blood pressure. However, most previous trials were in whites with few in blacks and Asians. Salt reduction may also reduce other cardiovascular risk factors (eg, urinary albumin excretion, arterial stiffness). However, few well-controlled trials have studied these effects. We carried out a randomized double-blind crossover trial of salt restriction with slow sodium or placebo, each for 6 weeks, in 71 whites, 69 blacks, and 29 Asians with untreated mildly raised blood pressure. From slow sodium to placebo, urinary sodium was reduced from 165+/-58 (+/-SD) to 110+/-49 mmol/24 hours (9.7 to 6.5 g/d salt). With this reduction in salt intake, there was a significant decrease in blood pressure from 146+/-13/91+/-8 to 141+/-12/88+/-9 mm Hg (P<0.001), urinary albumin from 10.2 (IQR: 6.8 to 18.9) to 9.1 (6.6 to 14.0) mg/24 hours (P<0.001), albumin/creatinine ratio from 0.81 (0.47 to 1.43) to 0.66 (0.44 to 1.22) mg/mmol (P<0.001), and carotid-femoral pulse wave velocity from 11.5+/-2.3 to 11.1+/-1.9 m/s (P<0.01). Subgroup analysis showed that the reductions in blood pressure and urinary albumin/creatinine ratio were significant in all groups, and the decrease in pulse wave velocity was significant in blacks only. These results demonstrate that a modest reduction in salt intake, approximately the amount of the current public health recommendations, causes significant falls in blood pressure in all 3 ethnic groups. Furthermore, it reduces urinary albumin and improves large artery compliance. Although both could be attributable to the falls in blood pressure, they may carry additional benefits on reducing cardiovascular disease above that obtained from the blood pressure falls alone.

  12. Effect of Duty Cycle on the Characteristics of Pulse-Modulhted Radio-Frequency Atmospheric Pressure Dielectric Barrier Discharge

    Institute of Scientific and Technical Information of China (English)

    LI Xuechun; WANG Huan; DING Zhenfeng; WANG Younian

    2012-01-01

    Using a one-dimensional fluid model, the pulse-modulated radio-frequency dielectric barrier discharge in atmospheric helium is described. The influences of the pulse duty cycle on the discharge characteristics are studied. The numerical results show that the dependence of discharge characteristics on the duty cycle is sensitive in the region of around 40% duty cycle under the given simulation parameters. In the case of a larger duty cycle, the plasma density is higher, the discharge becomes more intense, but the power consumption is higher. When the duty cycle is lower, one can get a weaker discharge, lower plasma density and higher electron temperature in the bulk plasma. In practical applications, in order to get a higher plasma density and a lower power consumption, it is more important to choose a suitable duty cycle to modulate the RF power supply.

  13. Association of pulse pressure with new-onset atrial fibrillation in patients with hypertension and left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Larstorp, Anne Cecilie K; Ariansen, Inger; Gjesdal, Knut

    2012-01-01

    Intervention For Endpoint reduction in hypertension study, a double-blind, randomized (losartan versus atenolol), parallel-group study, including 9193 patients with hypertension and electrocardiographic left ventricular hypertrophy. In 8810 patients with neither a history of AF nor AF at baseline, Minnesota......, and mean arterial pressure. When evaluated in the same model, the predictive effect of systolic and diastolic blood pressures together was similar to that of PP. In this population of patients with hypertension and left ventricular hypertrophy, PP was the strongest single blood pressure predictor of new...

  14. Influence of shock wave pressure amplitude and pulse repetition frequency on the lifespan, size and number of transient cavities in the field of an electromagnetic lithotripter

    Science.gov (United States)

    Huber, Peter; Jöchle, Knut; Debus, Jürgen

    1998-10-01

    Monitoring the generation of cavitation is of great interest for diagnostic and therapeutic use of ultrasound in medicine, since cavitation is considered to play a major role in nonthermal ultrasound interactions with tissue. Important parameters are the number of cavitation events and the energy released during the bubble collapse. This energy is correlated to the maximum bubble radius which is related to the cavitation lifespan. The aim of this study was therefore to investigate the influence of the acoustic pressure amplitude and the pulse repetition frequency (PRF) in the field of a lithotripter (Lithostar, Siemens) on the number, size and lifespan of transient cavitation bubbles in water. We used scattered laser light recorded by a photodiode and stroboscopic photographs to monitor the cavitation activity. We found that PRF (range 0.5-5 Hz) had no influence on the cavitation bubble lifespan and size, whereas lifespan and size increased with the acoustic pressure amplitude. In contrast, the number of cavitation events strongly increased with PRF, whereas the pressure amplitude had no significant influence on the number of cavitation events. Thus, by varying the pressure amplitude and PRF, it might be possible to deliver a defined relative number of cavitations at a defined relative energy level in a defined volume. This seems to be relevant to further studies that address the biological effects of transient cavitation occurring in the fields of lithotripters.

  15. Pressure dependency of aortic pulse wave velocity in vivo is not affected by vasoactive substances that alter aortic wall tension ex vivo.

    Science.gov (United States)

    Butlin, Mark; Lindesay, George; Viegas, Kayla D; Avolio, Alberto P

    2015-05-15

    Aortic stiffness, a predictive parameter in cardiovascular medicine, is blood pressure dependent and experimentally requires isobaric measurement for meaningful comparison. Vasoactive drug administration to change peripheral resistance and blood pressure allows such isobaric comparison but may alter large conduit artery wall tension, directly changing aortic stiffness. This study quantifies effects of sodium nitroprusside (SNP, vasodilator) and phenylephrine (PE, vasoconstrictor) on aortic stiffness measured by aortic pulse wave velocity (aPWV) assessed by invasive pressure catheterization in anaesthetized Sprague-Dawley rats (n = 7). This was compared with nondrug-dependent alteration of blood pressure through reduced venous return induced by partial vena cava occlusion. In vivo drug concentration was estimated by modeling clearance rates. Ex vivo responses of excised thoracic and abdominal aortic rings to drugs was measured using myography. SNP administration did not alter aPWV compared with venous occlusion (P = 0.21-0.87). There was a 5% difference in aPWV with PE administration compared with venous occlusion (P arteries in vivo. However, similar drug concentrations affect aortic ring wall tension ex vivo. Future studies investigating in vivo and ex vivo kinetics will need to elucidate mechanisms for this marked difference.

  16. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  17. Research on Multiple-point Calibration and Touch Pressure of Resistance Touch- screen%电阻式触摸屏多点校准及触摸压力研究

    Institute of Scientific and Technical Information of China (English)

    江秀红; 段富海; 曹阳; 胡爱玲

    2012-01-01

    针对电阻式触摸屏在小点状目标应用环境中存在触点判断不准确、灵敏度不高的问题,提出两种改进措施;其一在现有三点控准算法基础之上,增加校准点数提高转换精度;通过贪心算法对随机校准点集进行优化约简,并利用最小二乘法求得校准系数;其二为提高触摸坐标的准确性和触摸方式的鲁棒性,加入触摸压力检测和阈值判定来去除无效点击;测试结果表明,基于贪心算法的多点校准可提高坐标校准系数的精度,而触摸压力判定的加入则有效提高了轻触时的坐标精度.%For the inaccuracy and low sensitivity of the resistive touch-screen to fix position in small point target application, more points were collected to increase conversion accuracy based on existing three-point calibration. Greedy algorithm optimized and simplified the random calibrating spots, then least squares fitting algorithm calculated optimal calibration parameters with simplified spots assemble. In order to improve the accuracy of contact coordinate and adaptability of touch mode, the system adopted touch pressure measurement and threshold decision procedure to remove invalid click. Finally, test results show that multi-point calibration using greedy algorithm can improve the precision of coordinate calibration coefficients, and the adoption of Pressure Judgment increases the accuracy of gently touching coordinates effectively.

  18. Effect of working pressure and annealing temperature on microstructure and surface chemical composition of barium strontium titanate films grown by pulsed laser deposition

    Indian Academy of Sciences (India)

    Zahra Saroukhani; Nemat Tahmasebi; Seyed Mohammad Mahdavi; Ali Nemati

    2015-10-01

    Barium strontium titanate (BST, Ba1−SrTiO3) thin films have been extensively used in many dielectric devices such as dynamic random access memories (DRAMs). To optimize its characteristics, a microstructural control is essential. In this paper, Ba0.6Sr0.4TiO3 thin film has been deposited on the SiO2/Si substrate by the pulsed laser deposition (PLD) technique at three different oxygen working pressures of 100, 220 and 350 mTorr. Then the deposited thin films at 100 mTorr oxygen pressure were annealed for 50 min in oxygen ambient at three different temperatures: 650, 720 and 800°C. The effect of oxygen working pressure during laser ablation and thermal treatment on the films was investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis methods. X-ray photoelectron spectroscopy analysis was used to determine the surface chemical composition of the samples. The results indicate that the deposited BST film at low working pressure (100 mTorr) in PLD chamber shows a lower surface roughness than other working pressures (220 and 350 mTorr). The as-deposited films show an amorphous structure and would turn into polycrystalline structure at annealing temperature above 650°C. Increase of temperature would cause the formation of cubic and per-ovskite phases, improvement in crystalline peaks and also result in the decomposition of BST at high temperature (above 800°C). In addition, rising of temperature leads to the increase in size of grains and clusters. Therefore more roughness was found at higher temperatures as a result of a more heterogeneous growth and less tensions.

  19. Experimental and modeling study of the oxidation of acetaldehyde in an atmospheric-pressure pulsed corona discharge

    Science.gov (United States)

    Klett, C.; Touchard, S.; Vega-Gonzalez, A.; Redolfi, M.; Bonnin, X.; Hassouni, K.; Duten, X.

    2012-08-01

    This paper reports the results obtained for the degradation of acetaldehyde by an atmospheric plasma corona discharge working in a pulsed regime. It was shown that a few hundred ppm of acetaldehyde diluted in a pure N2 gas flow can be removed up to 80% by a discharge fed with an electric power lower than 1 W. Under the same conditions, adding up to 5% of O2 allowed the removal of up to 95% of the initial acetaldehyde. The main identified end products were CO2, CO and methanol. A quasi-homogeneous zero-dimensional chemical model was developed to investigate the respective efficiency of the discharge and post-discharge periods in the global removal of the pollutant. The identified main pathways of acetaldehyde degradation were quenching of N2 metastable states during plasma pulses and oxidation by O and OH radicals during the post-discharge. This latter contribution increased with input power because of ozone accumulation in the gas mixture acting as an additional oxygen reservoir.

  20. Control of Reactive Species Generated by Low-frequency Biased Nanosecond Pulse Discharge in Atmospheric Pressure Plasma Effluent

    Science.gov (United States)

    Takashima, Keisuke; Kaneko, Toshiro

    2016-09-01

    The control of hydroxyl radical and the other gas phase species generation in the ejected gas through air plasma (air plasma effluent) has been experimentally studied, which is a key to extend the range of plasma treatment. Nanosecond pulse discharge is known to produce high reduced electric field (E/N) discharge that leads to efficient generation of the reactive species than conventional low frequency discharge, while the charge-voltage cycle in the low frequency discharge is known to be well-controlled. In this study, the nanosecond pulse discharge biased with AC low frequency high voltage is used to take advantages of these discharges, which allows us to modulate the reactive species composition in the air plasma effluent. The utilization of the gas-liquid interface and the liquid phase chemical reactions between the modulated long-lived reactive species delivered from the air plasma effluent could realize efficient liquid phase chemical reactions leading to short-lived reactive species production far from the air plasma, which is crucial for some plasma agricultural applications.

  1. Size-controlled growth of ZnO nanowires by catalyst-free high-pressure pulsed laser deposition and their optical properties

    Directory of Open Access Journals (Sweden)

    W. Z. Liu

    2011-06-01

    Full Text Available Single crystalline ZnO nanowires were fabricated on Si (100 substrates by catalyst-free high-pressure pulsed laser deposition. It is found that the nanowires start to form when the substrate temperature and growth pressure exceed the critical values of 700 oC and 700 Pa, and their size strongly depends on these growth conditions. That is, the aspect ratio of the nanowires decreases with increasing temperature or decreasing pressure. Such a size dependence on growth conditions was discussed in terms of surface migration and scattering of ablated atoms. Room-temperature photoluminescence spectrum of ZnO nanowires shows a dominant near-band-edge emission peak at 3.28 eV and a visible emission band centered at 2.39 eV. Temperature-dependent photoluminescence studies reveal that the former consists of the acceptor-bound exciton and free exciton emissions; while the latter varies in intensity with the aspect ratio of the nanowires and is attributed to the surface-mediated deep level emission.

  2. Pulse Wave Velocity as Marker of Preclinical Arterial Disease: Reference Levels in a Uruguayan Population Considering Wave Detection Algorithms, Path Lengths, Aging, and Blood Pressure

    Directory of Open Access Journals (Sweden)

    Ignacio Farro

    2012-01-01

    Full Text Available Carotid-femoral pulse wave velocity (PWV has emerged as the gold standard for non-invasive evaluation of aortic stiffness; absence of standardized methodologies of study and lack of normal and reference values have limited a wider clinical implementation. This work was carried out in a Uruguayan (South American population in order to characterize normal, reference, and threshold levels of PWV considering normal age-related changes in PWV and the prevailing blood pressure level during the study. A conservative approach was used, and we excluded symptomatic subjects; subjects with history of cardiovascular (CV disease, diabetes mellitus or renal failure; subjects with traditional CV risk factors (other than age and gender; asymptomatic subjects with atherosclerotic plaques in carotid arteries; patients taking anti-hypertensives or lipid-lowering medications. The included subjects (n=429 were categorized according to the age decade and the blood pressure levels (at study time. All subjects represented the “reference population”; the group of subjects with optimal/normal blood pressures levels at study time represented the “normal population.” Results. Normal and reference PWV levels were obtained. Differences in PWV levels and aging-associated changes were obtained. The obtained data could be used to define vascular aging and abnormal or disease-related arterial changes.

  3. Pulse on Pulse

    DEFF Research Database (Denmark)

    Schmidt, Ulrik; Carlson, Merete

    2012-01-01

    Pulse on Pulse” investigates the relation between signifying processes and non-signifying material dynamism in the installation Pulse Room (2006-) by Mexican Canadian artist Rafael Lozano-Hemmer. In Pulse Room the sense of pulse is ambiguous. Biorhythms are transmitted from the pulsing energy...... and pulsating ‘room’. Hence, the visitors in Pulse Room are invited into a complex scenario that continuously oscillates between various aspects of signification (the light bulbs representing individual lives; the pulse itself as the symbolic ‘rhythm of life’) and instants of pure material processuality...... a multilayered sense of time and space that is central to the sensory experience of Pulse Room as a whole. Pulse Room is, at the very same time, an anthropomorfized archive of a past intimacy and an all-encompassing immersive environment modulating continuously in real space-time....

  4. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  5. Design of Radioactive Pulse Detection and Energy Calibration of Building Materials%建材放射性脉冲检测及其能量刻度设计

    Institute of Scientific and Technical Information of China (English)

    凌振宝; 黄健祥; 吴树军; 曾然; 曹桂欣

    2011-01-01

    为对建材放射性进行检测,设计了基于光电倍增管的建材放射性脉冲检测及其能量刻度系统.系统包括光电倍增管检测、放射性脉冲调理电路及集成12位A/D的单片机MSP430F1612对放射性脉冲峰值的采样电路.该系统将单片机处理的数据通过RS232串口传送至上位机,上位机采用Visual Basic 6.0软件对数据进行滤波拟合寻峰,通过获得的能量分析了建材中含有的放射性元素及其能量范围.系统较精确地实现了能量的刻度、自动寻峰和手动寻峰等,能准确判断的能量范围为0.01~2.97 MeV.实现了现场对建材放射性的检测,具有很大的实用性和便携性.%In order to detect radioactive materials, the pulse detection of radioactive materials and energy calibration , are designed based on the photomultiplier. The system includes photomultiplier detector, the radioactive pulse conditioning circuit and the circuit of MCU MSP430F1612, which has 12-bit A/D inside, to sample the peak of radioactive pulse and so on. The data through the Single chip microcomputer dealing will be transmitted to PC through the RS232 serial port. The PC uses the Visual Basic 6.0 software to filter and fit the data in order to search the peak. Analyzed the building materials have which radioactive element contained and it is energy range by the obtained energy. This system is much more accurate to achieve the energy scale, automatic and manual peak search, which could accurately determine the energy between 0. 01 to 2.97 MeV. The system has realized the detection of radioactive materials on the scene.

  6. Generation of quasi-monoenergetic protons from a double-species target driven by the radiation pressure of an ultraintense laser pulse

    Science.gov (United States)

    Pae, Ki Hong; Kim, Chul Min; Nam, Chang Hee

    2016-03-01

    In laser-driven proton acceleration, generation of quasi-monoenergetic proton beams has been considered a crucial feature of the radiation pressure acceleration (RPA) scheme, but the required difficult physical conditions have hampered its experimental realization. As a method to generate quasi-monoenergetic protons under experimentally viable conditions, we investigated using double-species targets of controlled composition ratio in order to make protons bunched in the phase space in the RPA scheme. From a modified optimum condition and three-dimensional particle-in-cell simulations, we showed by varying the ion composition ratio of proton and carbon that quasi-monoenergetic protons could be generated from ultrathin plane targets irradiated with a circularly polarized Gaussian laser pulse. The proposed scheme should facilitate the experimental realization of ultrashort quasi-monoenergetic proton beams for unique applications in high field science.

  7. Randomized Comparison of the Therapeutic Effect of Acupuncture, Massage, and Tachibana-Style-Method on Stiff Shoulders by Measuring Muscle Firmness, VAS, Pulse, and Blood Pressure

    Directory of Open Access Journals (Sweden)

    Kazuhiro Tachibana

    2012-01-01

    Full Text Available To compare the therapeutic efficacy of acupuncture, massage, and Tachibana-Ryojutsu (one of Japanese traditional body balance therapy techniques (SEITAI, on stiff shoulders, the subjects’ muscle firmness, blood pressure, pulse, VAS, and body temperature were measured before and after the treatment. Forty-seven volunteer subjects gave written informed consent to participate in this study. The subjects were randomly divided into three groups to receive acupuncture, massage, or Tachibana-Ryojutsu. Each therapy lasted for 90 seconds. The acupuncture treatment was applied by a retaining-needle at GB-21, massage was conducted softly on the shoulders, and Tachibana-Ryojutsu treated only the muscles and joints from the legs to buttocks without touching the shoulders or backs. The study indicated that the muscle firmness and VAS of the Tachibana-Ryojutsu group decreased significantly in comparison with the acupuncture and massage groups after treatment.

  8. Production mechanism of atomic nitrogen in atmospheric pressure pulsed corona discharge measured using two-photon absorption laser-induced fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Teramoto, Yoshiyuki; Ono, Ryo [Department of Advanced Energy, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 227-8568 (Japan); Oda, Tetsuji [Department of Electrical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2012-06-01

    To study the production mechanism of atomic nitrogen, the temporal profile and spatial distribution of atomic nitrogen are measured in atmospheric pressure pulsed positive corona discharge using two-photon absorption laser-induced fluorescence. The absolute atomic nitrogen density in the streamer filaments is estimated from decay rate of atomic nitrogen in N{sub 2} discharge. The results indicate that the absolute atomic nitrogen density is approximately constant against discharge energy. When the discharge voltage is 21.5 kV, production yield of atomic nitrogen produced by an N{sub 2} discharge pulse is estimated to be 2.9 - 9.8 Multiplication-Sign 10{sup 13} atoms and the energy efficiency of atomic nitrogen production is estimated to be about 1.8 - 6.1 Multiplication-Sign 10{sup 16} atoms/J. The energy efficiency of atomic nitrogen production in N{sub 2} discharge is constant against the discharge energy, while that in N{sub 2}/O{sub 2} discharge increases with discharge energy. In the N{sub 2}/O{sub 2} discharge, two-step process of N{sub 2} dissociation plays significant role for atomic nitrogen production.

  9. Exploring the polymerization of bioactive nano-cones on the inner surface of an organic tube by an atmospheric pressure pulsed micro-plasma jet

    Science.gov (United States)

    Xu, H. M.; Yu, J. S.; Chen, G. L.; Qiu, X. P.; Hu, W.; Chen, W. X.; Bai, H. Y.

    2015-12-01

    In this paper, the successful deposition of acrylic acid polymer (PAA) nano-cones on the inner surface of a polyvinyl chloride (PVC) tube using an atmospheric pressure pulsed plasma jet (APPJ) with acrylic acid (AA) monomer is presented. Optical emission spectroscopy (OES) measurements indicated that various reactive radicals, such as rad OH and rad O, existed in the plasma jet. Moreover, the pulsed current proportionally increased with the increase in the applied voltage. The strengthened stretching vibration of the carbonyl group (Cdbnd O) at 1700 cm-1, shown in the ATR-FTIR spectra, clearly indicated that the PAA was deposited on the PVC surface. The maximum height of the PAA nano-cones deposited by this method ranged from 150 to 200 nm. FTIR and XPS results confirmed the enhanced exposure of the carboxyl groups on the modified PVC surface, which was considered highly beneficial for successfully immobilizing a high density of biomolecules. The XPS data showed that the carbon ratios of the Csbnd OH/R and COOH/R groups increased from 7.03% and 2.6% to 18.69% and 6.81%, respectively (more than doubled) when an Ar/O2 plasma with AA monomer was applied to treat the inner surface of the PVC tube. Moreover, the enhanced attachment density of MC3T3-E1 bone cells was observed on the PVC inner surface coated with PAA nano-cones.

  10. Influence of the oxygen pressure on the physical properties of the pulsed-laser deposited Te doped SnO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chan y Diaz, E., E-mail: enrique.chan@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S.C. (CIMAV), Miguel de Cervantes Saavedra 120, Complejo industrial Chihuahua, Chihuahua 31109 (Mexico); Camacho, Juan M. [Applied Physics Department, CINVESTAV-IPN, Unidad Merida, 97310 Merida, Yucatan (Mexico); Duarte-Moller, A. [Centro de Investigacion en Materiales Avanzados, S.C. (CIMAV), Miguel de Cervantes Saavedra 120, Complejo industrial Chihuahua, Chihuahua 31109 (Mexico); Castro-Rodriguez, R.; Bartolo-Perez, P. [Applied Physics Department, CINVESTAV-IPN, Unidad Merida, 97310 Merida, Yucatan (Mexico)

    2010-10-22

    Tellurium doped tin oxide (Te:SnO{sub 2}) thin films were prepared by pulsed-laser deposition (PLD) on glass substrates at different oxygen pressures, and the effects of oxygen pressure on the physical properties of as-grown and post-annealed Te:SnO{sub 2} films were investigated. The as-grown films deposited between 1.0 and 50 mTorr showed some evidence of diffraction peaks, with electrical resistivity of {approx}8 x 10{sup 1} {Omega} cm, but increasing the oxygen pressure up to 100 mTorr, three diffraction peaks (1 1 0), (1 0 1) and (2 1 1) were observed containing the SnO{sub 2} tetragonal structure, at 100 mTorr the electrical resistivity decreased abruptly at minimum value of 4 x 10{sup -2} {Omega} cm, and increased reaching values of {approx}4 x 10{sup -1} {Omega} cm. The optical transmittance of the films increased with increasing oxygen pressure and high transmittance ({approx}87%) in VIS region by the films prepared at 100 mTorr and higher. The band gap of as-grown films was {approx}3.5 eV corresponding at of the SnO{sub 2}. After of post-annealed at 500 {sup o}C at atmospheric pressure for 30 min all films showed crystallization, and notable electrical resistivity changes were observed. The carrier density increased monotonically in the range of oxygen pressure between 1.0 and 100 mTorr, reaching values of {approx}2 x 10{sup 18} cm{sup -3}, then, it decreased abruptly in films grown at 125 mTorr. While the mobility of the free-carrier decreased in the range of oxygen pressure between 1.0 and 100 mTorr, reaching minimum values of {approx}5.8 cm{sup 2} V{sup -1} s{sup -1}. The optical transmittance showed similar characteristic like the as-grown films. The figure of merit at 100 mTorr of as-grown films had value {approx}1.2 x 10{sup -5} {Omega}{sup -1}, and for post-annealed films at 100 mTorr the figure of merit was similar {approx}1.7 x 10{sup -6} {Omega}{sup -1}, indicating they were the better films.

  11. Calibrated heat-pulse method for the assessment of maize water uptake Desenvolvimento do método do "pulso de calor" para determinação da absorção hídrica em milho

    Directory of Open Access Journals (Sweden)

    Antonio Odair Santos

    2000-03-01

    Full Text Available Plant water requirements are important aspects of crop production to be determined in the field, in order to judiciously manage crop water usage. Water uptake by field grown maize (Zea mays L., under well-watered conditions was verified with the heat-pulse system. The temperature difference between two radially inserted thermocouples, one 9 mm above and the other 4 mm below a heater piercing the maize stem, was measured every 0.3 seconds following emission of a heat-pulse. Comparisons of the heat-pulse system outputs, lysimetric measurement and transpiration model estimates were monitored on an hourly and daily basis. At normal and low atmospheric demand daily and hourly values of heat-pulse outputs and lysimetric measurement showed good agreement. Hourly agreement of a modified Penman-Monteith energy balance equation estimate and heat-pulse outputs showed accordance between measurement of sap flow and the plant water-loss theory. Study of the relationship between maize canopy water loss rate and heat velocity in the stem showed that these two parameters were proportional and a calibration factor of 1.51 for full soil foliage coverage was verified.A determinação a campo das necessidades hídricas de plantas é um aspecto importante da produção agrícola, para o manejo correto do uso da água pelos cultivos. A absorção de água por uma cultura de milho (Zea mays L., cultivado a campo, em condições de não limitação hídrica, foi verificada através da técnica do pulso de calor. Após a emissão de um pulso, procedeu-se a medições, a cada 0,3 segundos, do diferencial de temperatura entre dois termopares, inseridos radialmente no caule da planta. O primeiro foi colocado 9 mm acima e o segundo 4 mm abaixo de uma fonte de calor ("heater". Foram feitas comparações entre as medições feitas pela técnica do pulso de calor, lisímetro e estimativas da transpiração computadas em modelo, numa base horária e diária. Comparações entre

  12. 体检人群脉搏波传导速度与动态血压监测指标的相关性研究%Relationship between pulse wave velocity and parameters from ambulatory blood pressure monitoring

    Institute of Scientific and Technical Information of China (English)

    李曦; 胡荣; 芦燕玲; 于利群; 周生来

    2013-01-01

    目的:脉搏波传导速度与动态血压监测指标的关系.方法:行动态血压监测的体检者582例,根据血压水平分为正常血压组、血压正常高值组和高血压组,分析脉搏波传导速度与动态血压各指标之间的关系.结果:三组间动态血压各指标显著增高;颈股脉搏波传导速度三组间差异有统计学意义(P<0.05);高血压组颈桡脉搏波传导速度显著高于血压正常组.Pearson相关性分析:颈桡脉搏波传导速度与24 h平均SBP/DBP、白天平均SBP/DBP、夜间平均DBP、白天DBP负荷、夜间DBP负荷均呈正相关.颈股脉搏波传导速度与24h平均SBP、白天/夜间平均SBP、白天/夜间SBP负荷、白天SBP变化标准差均呈正相关.多元线性回归发现颈股脉搏波传导速度与24h平均SBP独立相关,颈桡脉搏波传导速度与白天平均DBP独立相关.结论:随血压水平程度升高,脉搏波传导速度明显增快.%Objective:To investigate relationship between pulse wave velocity and parameters from ambulatory blood pressure monitoring in examination persons.Methods:The 582 examination persons were taken ambulatory blood pressure monitoring and pulse wave velocity,the parameters were analyzed according blood pressure level.Results:The parameters from ambulatory blood pressure monitoring increase obviously in 3 groups.The carotid-femoral pulse wave velocity increase obviously in 3 groups.The carotid-radial pulse wave velocity were higher in hypertension group than normotensive.After analysis of pearson correlation,The carotidradial pulse wave velocity positively correlated with the mean 24h blood pressure,daytime mean blood pressure,night diastolic blood pressure,daytime diastolic blood pressure load,night diastolic blood pressure load.The carotid-femoral pulse wave velocity positively correlated with 24h systolic blood pressure,daytime and night systolic blood pressure,daytime and night systolic blood pressure load,daytime systolic blood

  13. Influence of surrounding gas, composition and pressure on plasma plume dynamics of nanosecond pulsed laser-induced aluminum plasmas

    Directory of Open Access Journals (Sweden)

    Mahmoud S. Dawood

    2015-10-01

    Full Text Available In this article, we present a comprehensive study of the plume dynamics of plasmas generated by laser ablation of an aluminum target. The effect of both ambient gas composition (helium, nitrogen or argon and pressure (from ∼5 × 10−7 Torr up to atmosphere is studied. The time- and space- resolved observation of the plasma plume are performed from spectrally integrated images using an intensified Charge Coupled Device (iCCD camera. The iCCD images show that the ambient gas does not significantly influence the plume as long as the gas pressure is lower than 20 Torr and the time delay below 300 ns. However, for pressures higher than 20 Torr, the effect of the ambient gas becomes important, the shortest plasma plume length being observed when the gas mass species is highest. On the other hand, space- and time- resolved emission spectroscopy of aluminum ions at λ = 281.6 nm are used to determine the Time-Of-Flight (TOF profiles. The effect of the ambient gas on the TOF profiles and therefore on the propagation velocity of Al ions is discussed. A correlation between the plasma plume expansion velocity deduced from the iCCD images and that estimated from the TOF profiles is presented. The observed differences are attributed mainly to the different physical mechanisms governing the two diagnostic techniques.

  14. On the pressure effect in energetic deposition of Cu thin films by modulated pulsed power magnetron sputtering: A global plasma model and experiments

    Science.gov (United States)

    Zheng, B. C.; Meng, D.; Che, H. L.; Lei, M. K.

    2015-05-01

    The modulated pulsed power magnetron sputtering (MPPMS) discharge processes are numerically modeled and experimentally investigated, in order to explore the effect of the pressure on MPPMS discharges as well as on the microstructure of the deposited thin films. A global plasma model has been developed based on a volume-averaged global description of the ionization region, considering the loss of electrons by cross-B diffusion. The temporal variations of internal plasma parameters at different pressures from 0.1 to 0.7 Pa are obtained by fitting the model to duplicate the experimental discharge data, and Cu thin films are deposited by MPPMS at the corresponding pressures. The surface morphology, grain size and orientation, and microstructure of the deposited thin films are investigated by scanning electron microscopy, transmission electron microscopy, and x-ray diffraction. By increasing the pressure from 0.1 to 0.7 Pa, both the ion bombardment energy and substrate temperature which are estimated by the modeled plasma parameters decrease, corresponding to the observed transition of the deposited thin films from a void free structure with a wide distribution of grain size (zone T) into an underdense structure with a fine fiber texture (zone 1) in the extended structure zone diagram (SZD). The microstructure and texture transition of Cu thin films are well-explained by the extended SZD, suggesting that the primary plasma processes are properly incorporated in the model. The results contribute to the understanding of the characteristics of MPPMS discharges, as well as its correlation with the microstructure and texture of deposited Cu thin films.

  15. Pulse oximetry: fundamentals and technology update

    Directory of Open Access Journals (Sweden)

    Nitzan M

    2014-07-01

    Full Text Available Meir Nitzan,1 Ayal Romem,2 Robert Koppel31Department of Physics/Electro-Optics, Jerusalem College of Technology, Jerusalem, Israel; 2Pulmonary Institute, Shaare Zedek Medical Center, Jerusalem, Israel; 3Neonatal/Perinatal Medicine, Cohen Children's Medical Center of New York/North Shore-LIJ Health System, New Hyde Park, NY, United StatesAbstract: Oxygen saturation in the arterial blood (SaO2 provides information on the adequacy of respiratory function. SaO2 can be assessed noninvasively by pulse oximetry, which is based on photoplethysmographic pulses in two wavelengths, generally in the red and infrared regions. The calibration of the measured photoplethysmographic signals is performed empirically for each type of commercial pulse-oximeter sensor, utilizing in vitro measurement of SaO2 in extracted arterial blood by means of co-oximetry. Due to the discrepancy between the measurement of SaO2 by pulse oximetry and the invasive technique, the former is denoted as SpO2. Manufacturers of pulse oximeters generally claim an accuracy of 2%, evaluated by the standard deviation (SD of the differences between SpO2 and SaO2, measured simultaneously in healthy subjects. However, an SD of 2% reflects an expected error of 4% (two SDs or more in 5% of the examinations, which is in accordance with an error of 3%–4%, reported in clinical studies. This level of accuracy is sufficient for the detection of a significant decline in respiratory function in patients, and pulse oximetry has been accepted as a reliable technique for that purpose. The accuracy of SpO2 measurement is insufficient in several situations, such as critically ill patients receiving supplemental oxygen, and can be hazardous if it leads to elevated values of oxygen partial pressure in blood. In particular, preterm newborns are vulnerable to retinopathy of prematurity induced by high oxygen concentration in the blood. The low accuracy of SpO2 measurement in critically ill patients and newborns

  16. Pulse pressure and michigan neuropathy screening instrument are independently associated with asymptomatic peripheral arterial disease among type 2 diabetes community residents: A community-based screening program in Taiwan

    Directory of Open Access Journals (Sweden)

    Li-Chi Fan

    2013-12-01

    Full Text Available Background: Peripheral arterial disease (PAD is one of the major manifestations of systemic atherosclerosis and plays an important role in low-extremity amputation in type 2 diabetic patients. The aim of this study was to explore the prevalence and risk factors for asymptomatic PAD in type 2 diabetic community residents. Methods: This cross-sectional study enrolled 552 type 2 diabetic adults (232 men and 320 women without subjective symptoms of intermittent claudication. We defined the PAD group as an ankle-brachial index (ABI ≤ 0.90, and the normal group as an ABI 0.91-1.30. Their clinical characteristics, Michigan Neuropathy Screening Instrument (MNSI scores and blood pressure were compared. Results: We discovered that 51 patients have asymptomatic PAD. Univariate logistic regression analysis revealed that age, history of stroke, longer duration of diabetes (> 10 years, unemployment or retirement, pulse pressure, systolic blood pressure, and high MNSI score (> 2 were risk factors for PAD. By multivariate logistic regression analysis, pulse pressure, high MNSI score, age, and history of stroke were independent risk factors with odds ratios (95% confidence intervals, CI of 1.032 (1.012-1.053, 2.359 (1.274-4.370, 1.050 (1.010-1.091, and 5.152 (1.985-13.368, respectively. Furthermore, the prevalence of PAD increased significantly with increment in the pulse pressure and MNSI. Conclusions: In summary, the overall prevalence of asymptomatic PAD in the type 2 diabetic adults was 9.2%. Age, history of stroke, pulse pressure and MNSI score may provide important clinical information. Primary care physicians should be aware of asymptomatic patients with high pulse pressure and MNSI scores.

  17. 老年原发性高血压患者动态脉压与脉搏波传导速度的相关性%Association Between Ambulatory Pulse Pressure and Pulse Wave Velocity in Elderly Hypertensive Patients

    Institute of Scientific and Technical Information of China (English)

    张会珍; 肖冬; 朱建英; 王辉; 李延敬

    2012-01-01

    目的 探讨老年高血压患者动态脉压与脉搏波传导速度的相关性.方法 选择原发性高血压患者229例.根据24h动态血压监测的结果,按照动态脉压值分为动态脉压<60 mmHg组(112例)和动态脉压≥60mmHg组(117例).2组均行颈桡脉搏波传导速度、血生化检测.结果 动态脉压≥60 mmHg组颈-桡动脉脉搏波传导速度显著高于动态脉压< 60 mmHg组(11.5±1.4 m/s比10.3±1.2 m/s,P<0.01);颈-桡动脉脉搏波传导速度与年龄、偶测收缩压、空腹血糖、总胆固醇、低密度脂蛋白胆固醇、24h收缩压、白昼收缩压、夜间收缩压、24h脉压、白昼脉压、夜间脉压呈正相关(r =0.302,0.248,0.224,0.306,0.365,0.466,0.492,0.372,0.552,0.546,0.488,均P<0.01);多元线性逐步回归分析发现,24h脉压、24h收缩压、年龄、低密度脂蛋白胆固醇是影响颈-桡动脉脉搏波传导速度主要危险因素.结论 老年高血压患者动态脉压与脉搏波传导速度密切相关.%Aim To investigate the association between ambulatory pulse pressure and carotid-radial pulse wave velocity (crPWV) in elderly patients with essential hypertension. Method According to the results of 24 h ambulatory pulse pressure (APP), 229 patients were divided to APPS60 mmHg group (re = 117) and APP<60 mmHg group (n = 112), crPWV, blood glucose and lipid profiles were recorded. Results The crPWV of APPss60 mmHg group was significantly higher than APP <60 mmHg group (11.5 ±1.4 m/s vs 10. 3 ±1.2 m/s, P<0.01). Pearson relation analysis showed that crPWV level positively correlated with age, systolic blood pressure (SBP), fasting blood glucose (FBG) , total cholesterol (TC), low density lipoprotein cholesterol (LDLC), 24hSBP, dSBP, nSBP, 24hPP, dPP, nPP (r = 0.302,0.248,0.224, 0.306, 0.365, 0.466, 0.492,0.372,0.552, 0.546, 0.488, allP<0.01). Multiple linear regression showed that 24hPP were significant and independent factor for crPWV in elderly patients with essential

  18. Plasma advanced glycation end products (AGEs) and NF-κB activity are independent determinants of diastolic and pulse pressure

    DEFF Research Database (Denmark)

    Sourris, Karly C; Lyons, Jasmine G; Dougherty, Sonia L;

    2013-01-01

    Abstract Background: High levels of circulating advanced glycation end products (AGEs) can initiate chronic low-grade activation of the immune system (CLAIS) with each of these factors independently associated with cardiovascular (CV) morbidity and mortality. Therefore, our objective was to chara......Abstract Background: High levels of circulating advanced glycation end products (AGEs) can initiate chronic low-grade activation of the immune system (CLAIS) with each of these factors independently associated with cardiovascular (CV) morbidity and mortality. Therefore, our objective...... was to characterize the relationship between serum AGEs, CLAIS and other risk factors for CV disease in normotensive non-diabetic individuals. Methods: We measured body mass index (BMI), waist-to-hip ratio (WHR), blood pressure, lipid and glucose profile in 44 non-diabetic volunteers (17 female, 27 males......). Carboxymethyl-lysine (CML) was measured by ELISA as a marker for circulating AGEs and NF-κB p65 activity as an inflammatory marker by DNA-binding in peripheral blood mononuclear cells lysates (PBMC). Results: Plasma CML concentrations were related to diastolic blood pressure (r=-0.51, p...

  19. Temporal and spatial profiles of emission intensities in atmospheric pressure helium plasma jet driven by microsecond pulse: Experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruixue; Zhang, Cheng; Yan, Ping; Shao, Tao, E-mail: st@mail.iee.ac.cn [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Shen, Yuan [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Zhu, Weidong [Department of Applied Science and Technology, Saint Peter' s University, Jersey City, New Jersey 07306 (United States); Babaeva, Natalia Yu.; Naidis, George V. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation)

    2015-09-28

    A needle-circular electrode structure helium plasma jet driven by microsecond pulsed power is studied. Spatially resolved emission results show that the emission intensity of He(3{sup 3}S{sub 1}) line decreases monotonically along the axial direction, while those of N{sub 2}(C{sup 3}Π{sub u}), N{sub 2}{sup +}(B{sup 2}∑{sup +}{sub u}), and O(3p{sup 5}P) reach their maxima at 3 cm, 2.6 cm, and 1.4 cm, respectively. The plasma plume of the four species shows different characteristics: The N{sub 2} emission plume travels at a fast speed along the entire plasma jet; the N{sub 2}{sup +} emission plume is composed of a bright head and relatively weak tail and travels a shorter distance than the N{sub 2} emission plume; the He emission plume travels at a slower speed for only a very short distance; propagation of the O emission plume is not observed. Results of calculation of radiation fluxes emitted by positive streamers propagating along helium plasma jets are presented. It is shown, in agreement with the results of the present experiment and with other available experimental data, that the intensities of radiation of N{sub 2}(C{sup 3}Π{sub u}) molecules and He(3{sup 3}S{sub 1}) atoms vary with time (along the plasma jet) quite differently. The factors resulting in this difference are discussed.

  20. Transducer Development and Characterization for Underwater Acoustic Neutrino Detection Calibration.

    Science.gov (United States)

    Saldaña, María; Llorens, Carlos D; Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-01-01

    A short bipolar pressure pulse with "pancake" directivity is produced and propagated when an Ultra-High Energy (UHE) neutrino interacts with a nucleus in water. Nowadays, acoustic sensor networks are being deployed in deep seas to detect this phenomenon as a first step toward building a neutrino telescope. In order to study the feasibility of the method, it is critical to have a calibrator that is able to mimic the neutrino signature. In previous works the possibility of using the acoustic parametric technique for this aim was proven. In this study, the array is operated at a high frequency and, by means of the parametric effect, the emission of the low-frequency acoustic bipolar pulse is generated mimicking the UHE neutrino acoustic pulse. To this end, the development of the transducer to be used in the parametric array is described in all its phases. The transducer design process, the characterization tests for the bare piezoelectric ceramic, and the addition of backing and matching layers are presented. The efficiencies and directivity patterns obtained for both primary and parametric beams confirm that the design of the proposed calibrator meets all the requirements for the emitter.

  1. Transducer Development and Characterization for Underwater Acoustic Neutrino Detection Calibration

    Science.gov (United States)

    Saldaña, María; Llorens, Carlos D.; Felis, Ivan; Martínez-Mora, Juan Antonio; Ardid, Miguel

    2016-01-01

    A short bipolar pressure pulse with “pancake” directivity is produced and propagated when an Ultra-High Energy (UHE) neutrino interacts with a nucleus in water. Nowadays, acoustic sensor networks are being deployed in deep seas to detect this phenomenon as a first step toward building a neutrino telescope. In order to study the feasibility of the method, it is critical to have a calibrator that is able to mimic the neutrino signature. In previous works the possibility of using the acoustic parametric technique for this aim was proven. In this study, the array is operated at a high frequency and, by means of the parametric effect, the emission of the low-frequency acoustic bipolar pulse is generated mimicking the UHE neutrino acoustic pulse. To this end, the development of the transducer to be used in the parametric array is described in all its phases. The transducer design process, the characterization tests for the bare piezoelectric ceramic, and the addition of backing and matching layers are presented. The efficiencies and directivity patterns obtained for both primary and parametric beams confirm that the design of the proposed calibrator meets all the requirements for the emitter. PMID:27490547

  2. Comparative Study on the Pulse Wave Variables and Sasang Constitution in Cerebral Infarction Patients and Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Ko KiDuk

    2007-06-01

    Full Text Available This study was performed to determine whether a pulse analyzer was useful 1 to characterize the variables of pulse wave of cerebral infarction patieno (CI, compared with those of healthy subjects, as well as 2 to determine Sasang Constitution in CI and healthy subjects. 1. Calibrated in Gwan, the amount of energy(Energy, height of main peak(H1, height of aorticvalley(H2, height of aortic peak(H3, total area of pulse wave(At, and area of main peak width(Aw of the CI group were higher than those of the healthy group. 2. Calibrated in Cheek, Energy, H1, H2, H3, height of valve valley(H4, At, Aw, and main peak angle(MPA of the CI group were higher than those of the healthy group. 3. Among the healthy (subjects group, Taeumin showed the highest contact pressure(CP and height of valve peak(H5 calibrated in Chon. The main peak width divided by whole time of pulse wave(MPW/T calibrated in Gwan and Cheok, was highest in Soyangin and was lowest in Taeumin. The H3 divided by H1(H3/H1 and the time to valve valley minus the time to main peak and divided by T[(T4-T1/T] calibrated in Cheek were highest in Soyangin. The time to main peak(T1 was longest in Soumin. 4. Among the CI group, At calibrated in Chon was widest in Taeumin and was narrowest in Soumin The time to aortic peak(T3 calibrated in Cheek was longest in Soumin and was shortest in Soyangin. The time to valve peak(T5 was shortest in Soyangin. 5. There were main effects of cerebral infarction in the area of systolic period(As and area of diastolic period(Ad calibrated in Chon, Energy calibrated in Cwan, and Energy, H1, H2, H3, (H4+H5/Hl, and MPA calibrated in Cheek. 6. There were main effects of Sasang Constitution in (T4-T1/T, area of systolic period(As, and Ad calibrated in Chon. 7. The interactions between the cerebral infarction and Sasang Constitution were observed in H5/H1 , T, At, As, Ad, and MPA calibrated in Chon, H4, T4, (T4-T1/T, As, and Ad calibrated in Cwan, and 74,75, and MPW calibrated

  3. fs/ns dual-pulse LIBS analytic survey for copper-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Santagata, A. [CNR-IMIP, Unita Operativa di Potenza, Zona Industriale di Tito Scalo, 85050 Tito Scalo, PZ (Italy)], E-mail: santagata@pz.imip.cnr.it; Teghil, R. [Universita degli Studi della Basilicata, Dipartimento di Chimica, Via N. Sauro 85, 85100 Potenza (Italy); Albano, G.; Spera, D.; Villani, P. [CNR-IMIP, Unita Operativa di Potenza, Zona Industriale di Tito Scalo, 85050 Tito Scalo, PZ (Italy); De Bonis, A. [Universita degli Studi della Basilicata, Dipartimento di Chimica, Via N. Sauro 85, 85100 Potenza (Italy); Parisi, G.P. [CNR-IMIP, Unita Operativa di Potenza, Zona Industriale di Tito Scalo, 85050 Tito Scalo, PZ (Italy); Galasso, A. [Universita degli Studi della Basilicata, Dipartimento di Chimica, Via N. Sauro 85, 85100 Potenza (Italy)

    2007-12-15

    The quantitative analytic capability of a fs/ns dual-pulse Laser-Induced Breakdown Spectroscopy technique, based on the orthogonal reheating of a fs-laser ablation plume by a ns-laser pulse, is presented. In this work, it is shown how the effect played by the delay times between the two laser beams can vary the analytical response of this dual-pulse LIBS configuration. In order to address this task, the Sn, Pb and Zn calibration curves of five certified copper-based samples have been investigated. These calibration curves have been obtained, in air at atmospheric pressure, by integrating the emission data collected in two different inter-pulse delay zones, one in the delay interval of 1-41 {mu}s, the other within the range of 46-196 {mu}s. For drawing the species calibration curves, the emission intensities of the considered Pb(I), Sn(I) and Zn(I) electronic transitions have been normalized with a non-resonant Cu(I) emission line. The experimental results have shown that, by varying the inter-pulse delay between the two laser beams, complementary analytical results can be induced. By considering at once all data acquired within the inter-pulse delay time of 1-196 {mu}s, this hypothesis has been strengthened. The calibration curves obtained in this way are characterized by excellent linear regression coefficients (0.988-0.999) despite of the large Sn, Pb and Zn compositional variation of the targets employed. The results presented reveal, for the first time, that, by taking into account the role played by the inter-pulse delay time between the two laser beams, the fs/ns dual-pulse LIBS configuration here used can be improved and provide very good opportunities for performing quantitative analysis of copper-based alloys.

  4. NO density and gas temperature measurements in atmospheric pressure nanosecond repetitively pulsed (NRP) discharges by Mid-IR QCLAS

    Science.gov (United States)

    Simeni Simeni, Marien; Stancu, Gabi-Daniel; Laux, Christophe

    2014-10-01

    Nitric oxide is a key species for many processes: in combustion, in human skin physiology... Recently, NO-ground state absolute density measurements produced by atmospheric pressure NRP discharges were carried out in air as a function of the discharge parameters, using Quantum Cascade Laser Absorption Spectroscopy. These measurements were space averaged and performed in the post-discharge region in a large gas volume. Here we present radial profiles of NO density and temperature measured directly in the discharge for different configurations. Small plasma volume and species densities, high temperature and EM noise environment make the absorption diagnostic challenging. For this purpose the QCLAS sensitivity was improved using a two-detector system. We conducted lateral absorbance measurements with a spatial resolution of 300 μm for two absorption features at 1900.076 and 1900.517 cm-1. The radial temperature and NO density distributions were obtained from the Abel inverted lateral measurements. Time averaged NO densities of about 1.E16 cm-3 and gas temperature of about 1000K were obtained in the center of the discharge. PLASMAFLAME Project (Grant No ANR-11-BS09-0025).

  5. Finishing of AT-cut quartz crystal wafer with nanometric thickness uniformity by pulse-modulated atmospheric pressure plasma etching.

    Science.gov (United States)

    Yamamura, Kazuya; Ueda, Masaki; Shibahara, Masafumi; Zettsu, Nobuyuki

    2011-04-01

    Quartz resonator is a very important device to generate a clock frequency for information and telecommunication system. Improvement of the productivity of the quartz resonator is always required because a huge amount of the resonator is demanded for installing to various electronic devices. Resonance frequency of the quartz resonator is decided by the thickness of the quartz crystal wafer. Therefore, it is necessary to uniform the thickness distribution of the wafer with nanometric level. We have proposed the improvement technique of the thickness distribution of the quartz crystal wafer by numerically controlled correction using atmospheric pressure plasma which is non-contact and chemical removal technique. Heating effects of the quartz wafer in the removal rate and the correction accuracy were investigated. The heating of the substrate and compensate of the scanning speed of the worktable according to the variation of the surface temperature enabled an increase of 50% in the etching rate and 10-nanometric-level accuracy in the correction of the thickness distribution of the quartz wafer, respectively.

  6. The Advanced LIGO Photon Calibrators

    CERN Document Server

    Karki, S; Kandhasamy, S; Abbott, B P; Abbott, T D; Anders, E H; Berliner, J; Betzwieser, J; Daveloza, H P; Cahillane, C; Canete, L; Conley, C; Gleason, J R; Goetz, E; Kissel, J S; Izumi, K; Mendell, G; Quetschke, V; Rodruck, M; Sachdev, S; Sadecki, T; Schwinberg, P B; Sottile, A; Wade, M; Weinstein, A J; West, M; Savage, R L

    2016-01-01

    The two interferometers of the Laser Interferometry Gravitaional-wave Observatory (LIGO) recently detected gravitational waves from the mergers of binary black hole systems. Accurate calibration of the output of these detectors was crucial for the observation of these events, and the extraction of parameters of the sources. The principal tools used to calibrate the responses of the second-generation (Advanced) LIGO detectors to gravitational waves are systems based on radiation pressure and referred to as Photon Calibrators. These systems, which were completely redesigned for Advanced LIGO, include several significant upgrades that enable them to meet the calibration requirements of second-generation gravitational wave detectors in the new era of gravitational-wave astronomy. We report on the design, implementation, and operation of these Advanced LIGO Photon Calibrators that are currently providing fiducial displacements on the order of $10^{-18}$ m/$\\sqrt{\\textrm{Hz}}$ with accuracy and precision of better ...

  7. The Advanced LIGO photon calibrators

    Science.gov (United States)

    Karki, S.; Tuyenbayev, D.; Kandhasamy, S.; Abbott, B. P.; Abbott, T. D.; Anders, E. H.; Berliner, J.; Betzwieser, J.; Cahillane, C.; Canete, L.; Conley, C.; Daveloza, H. P.; De Lillo, N.; Gleason, J. R.; Goetz, E.; Izumi, K.; Kissel, J. S.; Mendell, G.; Quetschke, V.; Rodruck, M.; Sachdev, S.; Sadecki, T.; Schwinberg, P. B.; Sottile, A.; Wade, M.; Weinstein, A. J.; West, M.; Savage, R. L.

    2016-11-01

    The two interferometers of the Laser Interferometry Gravitational-wave Observatory (LIGO) recently detected gravitational waves from the mergers of binary black hole systems. Accurate calibration of the output of these detectors was crucial for the observation of these events and the extraction of parameters of the sources. The principal tools used to calibrate the responses of the second-generation (Advanced) LIGO detectors to gravitational waves are systems based on radiation pressure and referred to as photon calibrators. These systems, which were completely redesigned for Advanced LIGO, include several significant upgrades that enable them to meet the calibration requirements of second-generation gravitational wave detectors in the new era of gravitational-wave astronomy. We report on the design, implementation, and operation of these Advanced LIGO photon calibrators that are currently providing fiducial displacements on the order of 1 0-18m /√{Hz } with accuracy and precision of better than 1%.

  8. 中心动脉脉压是影响大动脉僵硬度的主要因素%Central pulse pressure but not brachial blood pressure is the predominant factor affecting aortic arterial stiffness

    Institute of Scientific and Technical Information of China (English)

    肖文凯; 叶平; 白永怿; 骆雷鸣; 吴红梅; 高鹏

    2015-01-01

    目的:观察高血压患者及血压正常人群中心动脉血流动力学差异;探讨哪种血压指标与动脉僵硬度及血管损害标志物更密切相关。方法从北京地区社区人群中筛选出820名高血压患者,同时入选820名与之年龄、性别相匹配的血压正常者。采用脉搏波传播速度(PWV)自动测量系统测定颈-股动脉PWV和颈-桡动脉PWV;应用张力测量法测量中心动脉压和中心动脉脉搏波增强指数(AIx)。同时血浆同型半胱氨酸(HCY),高敏C反应蛋白(HsCRP)及N末端脑利钠肽前体(NT-proBNP)被测定。结果无论是高血压患者还是血压正常人群,中心动脉收缩压和脉压显著低于相应的肱动脉收缩压和脉压,这种脉压扩增在血压正常组9.85±6.55 mmHg明显低于高血压组12.64±6.69 mmHg,但在脉压扩增比上两组未见差异。大动脉僵硬度受血压及年龄的影响,高血压组具有较高的颈股动脉PWV和中心动脉AIx,脉压扩增比随年龄的增长而递减。单因素分析见中心脉压相对其它血压指标与动脉僵硬度和血管损害标志物的相关性更强;多元逐步回归分析显示颈股动脉PWV和中心动脉AIx受中心脉压的独立影响而外周平均动脉压及脉压未进入回归方程。结论中心动脉脉压相对其它血压指标可能是中心动脉僵硬度更直接的指示器和更好的血管老化的标志,未来的临床试验中可能更多地将中心动脉压作为治疗的靶目标值。%Objective To investigate the differences in central hemodynamic indices between hypertensive and normotensive subjects and identify the blood pressure index that the most strongly correlate with arterial stiffness and vascular damage markers. Methods A cohort of 820 hypertensive patients and 820 normotensive individuals matched for age and gender were enrolled in this study. We measured carotid-femoral and carotid-radial pulse wave velocity (PWV), aortic

  9. Influence of surface emission processes on a fast-pulsed dielectric barrier discharge in air at atmospheric pressure

    Science.gov (United States)

    Pechereau, François; Bonaventura, Zdeněk; Bourdon, Anne

    2016-08-01

    This paper presents simulations of an atmospheric pressure air discharge in a point-to-plane geometry with a dielectric layer parallel to the cathode plane. Experimentally, a discharge reignition in the air gap below the dielectrics has been observed. With a 2D fluid model, it is shown that due to the fast rise of the high voltage applied and the sharp point used, a first positive spherical discharge forms around the point. Then this discharge propagates axially and impacts the dielectrics. As the first discharge starts spreading on the upper dielectric surface, in the second air gap with a low preionization density of {{10}4}~\\text{c}{{\\text{m}}-3} , the 2D fluid model predicts a rapid reignition of a positive discharge. As in experiments, the discharge reignition is much slower, a discussion on physical processes to be considered in the model to increase the reignition delay is presented. The limit case with no initial seed charges in the second air gap has been studied. First, we have calculated the time to release an electron from the cathode surface by thermionic and field emission processes for a work function φ \\in ≤ft[3,4\\right] eV and an amplification factor β \\in ≤ft[100,220\\right] . Then a 3D Monte Carlo model has been used to follow the dynamics of formation of an avalanche starting from a single electron emitted at the cathode. Due to the high electric field in the second air gap, we have shown that in a few nanoseconds, a Gaussian cloud of seed charges is formed at a small distance from the cathode plane. This Gaussian cloud has been used as the initial condition of the 2D fluid model in the second air gap. In this case, the propagation of a double headed discharge in the second air gap has been observed and the reignition delay is in rather good agreement with experiments.

  10. Sensor Calibration Design Based on D-Optimality Criterion

    Directory of Open Access Journals (Sweden)

    Hajiyev Chingiz

    2016-09-01

    Full Text Available In this study, a procedure for optimal selection of measurement points using the D-optimality criterion to find the best calibration curves of measurement sensors is proposed. The coefficients of calibration curve are evaluated by applying the classical Least Squares Method (LSM. As an example, the problem of optimal selection for standard pressure setters when calibrating a differential pressure sensor is solved. The values obtained from the D-optimum measurement points for calibration of the differential pressure sensor are compared with those from actual experiments. Comparison of the calibration errors corresponding to the D-optimal, A-optimal and Equidistant calibration curves is done.

  11. Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy

    Science.gov (United States)

    Urbanek, Bożena; Ruta, Jan; Kudryński, Krzysztof; Ptaszyński, Paweł; Klimczak, Artur; Wranicz, Jerzy Krzysztof

    2016-01-01

    Background The aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT). Material/Methods Forty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed. Results Short-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity. Conclusions During short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead. PMID:27305349

  12. Reference values of one-point carotid stiffness parameters determined by carotid echo-tracking and brachial pulse pressure in a large population of healthy subjects.

    Science.gov (United States)

    Vriz, Olga; Aboyans, Victor; Minisini, Rosalba; Magne, Julien; Bertin, Nicole; Pirisi, Mario; Bossone, Eduardo

    2017-03-02

    Arterial stiffness can predict cardiovascular events, and the aim of this study was to produce age- and sex-specific reference values for echo-tracking carotid stiffness in healthy subjects. A total of 900 subjects (500 males, mean age 45.8±19 years) were enrolled. Common carotid artery stiffness and compliance, using a high-definition echo-tracking ultrasound system, were evaluated. To compare stiffness parameters across the different age groups, individual scores were transformed into T-scores, indicating how many standard deviation (s.d.) units an individual's score was above or below the mean that was observed in the group including same-sex individuals aged 36 to 44 years. Carotid stiffness was similar among genders, except compliance, which was lower in women (Pgroups. Stiffness parameters increased significantly with age, but the opposite occurred for compliance. The T-score was found to increase significantly across all age groups, with a steeper increase in stiffness around the age of 60 years in women. For each T-score s.d., the corresponding carotid absolute values for arterial stiffness and compliance were obtained. In a multivariate model, carotid stiffness parameters were constantly and independently associated with age, mean arterial pressure, pulse pressure, heart rate and body mass index. Our study provides a normogram of carotid arterial stiffness and compliance indices obtained with the echo-tracking method in a large population of healthy subjects stratified by gender and age that can be used in clinical practice.Hypertension Research advance online publication, 2 March 2017; doi:10.1038/hr.2017.24.

  13. Effect of oral nitrates on pulse pressure and arterial elasticity in patients aged over 65 years with refractory isolated systolic hypertension: study protocol for a randomized controlled trial

    Science.gov (United States)

    2013-01-01

    Background Isolated systolic hypertension is a highly prevalent disease among the elderly. The little available evidence on the efficacy of nitrates for treating the disease is based on small experimental studies. Methods/design We performed a multicenter, randomized, double-blind, phase III, placebo-controlled trial in 154 patients aged over 65 years with refractory isolated systolic hypertension. Patients were randomized to placebo or 40 mg/day of extended-release isosorbide mononitrate added to standard therapy and titrated to 60 mg/day at week 6 if blood pressure exceeded 140/90 mmHg. The primary objective was to assess the effect on clinical pulse pressure of extended-release isosorbide mononitrate added to standard therapy in patients aged over 65 years with refractory isolated systolic hypertension after 3 months of treatment. The secondary objectives were as follows: to quantify the effect of adding the study drug on central blood pressure and vascular compliance using the augmentation index and pulse wave velocity; to evaluate the safety profile by recording adverse effects (frequency, type, severity) and the percentage of patients who had to withdraw from the trial because of adverse events; to quantify the percentage of patients who reach a clinical systolic blood pressure <140 mmHg or <130 mmHg measured by ambulatory blood pressure monitoring; and to quantify the change in pulse pressure measured by ambulatory blood pressure monitoring. Discussion Few clinical trials have been carried out to test the effect of oral nitrates on isolated systolic hypertension, even though these agents seem to be effective. Treatment with extended-release isosorbide mononitrate could improve control of systolic blood pressure without severe side effects, thus helping to reduce the morbidity and mortality of the disease. Trial registration EUDRACT Number: 2012-002988-10 PMID:24228894

  14. 高血压患者颈动脉硬化与动态脉压、动态脉压指数的关系及其危险因素分析%Relationship of carotid atherosclerosis with ambulatory pulse pressure and ambulatory pulse pressure index and its risk factors in patients with essential hypertension

    Institute of Scientific and Technical Information of China (English)

    李晖; 袁建明; 张源明

    2011-01-01

    目的 探讨动态脉压(ambulatory pulse pressure,APP)、动态脉压指数(ambulatory pulse pressure index,APPI)对原发性高血压(essential hypertension,EH)患者颈动脉硬化的影响.方法 对274例EH患者进行动态血压监测(ABPM)和颈动脉超声检查,分析APP、APPI与颈动脉内膜中层厚度(intimamedia thickness,IMT)关系及颈动脉硬化的相关危险因素.所有病人分为两组:APP(24 hAPP)<60 mmHg组157例和APP≥60 mmHg组117例.结果 274例患者中APP≥60 mmHg组颈动脉IMT明显大于APP<60 mmHg组(P<0.05).颈动脉IMT斑块阳性和阴性组比较,24 hSBP、24 hMAP、24 hPP差异具有统计学意义.多元Logistic回归分析表明,24 hAPP(OR=1.033,95%CI:1.018-1.048,P=0.000 1)、男性患者(OR=2.07,95%CI:1.183-3.613,P=0.011)及吸烟(OR=1.808,95%CI:1.073-3.046,P=0.026)是颈动脉IMT增加的独立预测指标.结论 随着APP的逐渐增大,颈动脉IMT明显增加,24 hAPP、男性及吸烟是颈动脉IMT增加的独立预测指标.%Objective To investigate the effect of ambulatory pulse pressure( APP )and ambulatory pulse pressure index on carotid intimamedia thickness in essential hypertension( EH ) patients. Methods A total of 274 patients were enrolled in this study. All patients underwent ambulatory blood pressure monitoring ( ABPM ) and B-mode Doppler ultrasonography. The patients were divided into two groups : APP <60 mmHg group( n = 157 )and APP ≥ 60 mmHg group ( n = 117 ). The relationships between carotid IMT and APP or APPI were analyzed, and the risk factors of carotid atherosclerosis were analyzed in EH patients. Results Compared with APP < 60 mmHg group ,IMT significantly increased in APP ≥60 mmHg group [ ( 0. 61 ±0. 35 ) cm vs ( 0. 79 ± 0. 37 )cm , P < 0. 05]. Between positive and negative carotid IMT patients,24 hSBP,24 hMAP and 24 hAPP were statistically different. Multiple logistic regression analysis showed that the 24 hAPP ( OR = 1. 033 .95% CI ∶ 1. 018 - 1. 048 ,P = 0. 000 1

  15. The Role of Ambient Gas and Pressure on the Structuring of Hard Diamond-Like Carbon Films Synthesized by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Andrei C. Popescu

    2015-06-01

    Full Text Available Hard carbon thin films were synthesized on Si (100 and quartz substrates by the Pulsed Laser Deposition (PLD technique in vacuum or methane ambient to study their suitability for applications requiring high mechanical resistance. The deposited films’ surface morphology was investigated by scanning electron microscopy, crystalline status by X-ray diffraction, packing and density by X-ray reflectivity, chemical bonding by Raman and X-ray photoelectron spectroscopy, adherence by “pull-out” measurements and mechanical properties by nanoindentation tests. Films synthesized in vacuum were a-C DLC type, while films synthesized in methane were categorized as a-C:H. The majority of PLD films consisted of two layers: one low density layer towards the surface and a higher density layer in contact with the substrate. The deposition gas pressure played a crucial role on films thickness, component layers thickness ratio, structure and mechanical properties. The films were smooth, amorphous and composed of a mixture of sp3-sp2 carbon, with sp3 content ranging between 50% and 90%. The thickness and density of the two constituent layers of a film directly determined its mechanical properties.

  16. Plasma Renalase is Not Associated with Blood Pressure and Brachial-Ankle Pulse Wave Velocity in Chinese Adults With Normal Renal Function

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2016-11-01

    Full Text Available Background/Aims: This study aimed to investigate the association of renalase with blood pressure (BP and brachial-ankle pulse wave velocity (baPWV in order to better understand the role of renalase in the pathogenesis of hypertension and atherosclerosis. Methods: A total of 344 subjects with normal kidney function were recruited from our previously established cohort in Shaanxi Province, China. They were divided into the normotensive (NT and hypertensive (HT groups or high baPWV and normal baPWV on the basis of BP levels or baPWV measured with an automatic waveform analyzer. Plasma renalase was determined through an enzyme-linked immunosorbent assay. Results: Plasma renalase did not significantly differ between HT and NT groups (3.71 ± 0.69 µg/mL vs. 3.72 ± 0.73 μg/mL, P = 0.905 and between subjects with and without high baPWV (3.67 ± 0.66 µg/mL vs. 3.73 ± 0.74 µg/mL, P = 0.505. However, baPWV was significantly higher in the HT group than in the NT group (1460.4 ± 236.7 vs. 1240.7 ± 174.5 cm/s, P Conclusion: Plasma renalase may not be associated with BP and baPWV in Chinese subjects with normal renal function.

  17. Spatiotemporal Evolution of Ar(3P2) Metastable Density Generated in a Pulsed DC Atmospheric Pressure micro-Plasma Jet Impinging on a Glass Plate

    Science.gov (United States)

    Gazeli, K.; Bauville, G.; Es-Sebbar, Et-T.; Fleury, M.; Neveau, O.; Pasquiers, St.; Santos Sousa, J.; Laboratoire de Physique des gaz et des plasmas Team

    2016-09-01

    Atmospheric Pressure micro-Plasma Jets (APPJs) are promising tools in various domains such as biomedical and material treatments. In this work, APPJs are produced in pure argon at variable flow rates (i.e., 200, 400 and 600 sccm), by applying high voltage positive pulses (250 ns in FWHM and 6 kV in amplitude) at a repetition frequency of 20 kHz. The generated plasma impacts an ungrounded glass plate placed at a distance of 5 mm from the tube's orifice and perpendicular to the streamers propagation. At these conditions, a diffuse discharge is established resulting in a non-filamentary and reproducible plasma, in contrast with the free-jet case (no target). This allows the quantification of the absolute density of the Ar(1s5) metastable state by using laser absorption spectroscopy to probe the transition 1s5 -> 2p9 at 811.531 nm. The experiments show the dependence on the gas flow rate and on the axial and radial positions of the maximum density (6-9x1013 cm-3) . At 200 sccm, it is obtained close to the tube's orifice, while with increasing flow rate it is displaced towards the plate. Regarding the radial variation, density maxima are obtained in a small area around the streamers propagation axis.

  18. The effects of oxygen pressure on disordering and magneto-transport properties of Ba{sub 2}FeMoO{sub 6} thin films grown via pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong-Won; Mhin, Sungwook; Jones, Jacob L.; Norton, David P. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ghosh, Siddhartha, E-mail: ghoshsid@gmail.com; Buvaev, Sanal; Hebard, Arthur F. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

    2015-07-21

    Epitaxial Ba{sub 2}FeMoO{sub 6} thin films were grown via pulsed laser deposition under low oxygen pressure and their structural, chemical, and magnetic properties were examined, focusing on the effects of oxygen pressure. The chemical disorder, off-stoichiometry in B site cations (Fe and Mo) increased with increasing oxygen pressure and thus magnetic properties were degraded. Interestingly, in contrast, negative magneto-resistance, which is the characteristics of this double perovskite material, was enhanced with increasing oxygen pressure. It is believed that phase segregation of highly disordered thin films is responsible for the increased magneto-resistance of thin films grown at high oxygen pressure. The anomalous Hall effect, which behaves hole-like, was also observed due to spin-polarized itinerant electrons under low magnetic field below 1 T and the ordinary electron-like Hall effect was dominant at higher magnetic fields.

  19. Experimental Research on Performance of Self-excited Inspiratory Pulsed Jet Device under Different Ambient Pressures%不同围压下自激吸气式脉冲射流装置性能试验研究

    Institute of Scientific and Technical Information of China (English)

    高传昌; 黄晓亮; 赵礼; 杜俐

    2011-01-01

    To address the technical problems of mud processing of deep water reservoirs and meet the urgent needs, experiments were conducted to assess the performance of a self-excited inspiratory pulsed jet device under different ambient pressures with testing device developed by ourselves, I n which the influence of the driving pressure, ambient pressure and standoff distance on the impact force of pulsed jet were analyzed. Preliminary research on the change of inspiratory quantity and start-up inspiratory pressure was also carried out. As the experimental results demonstrate, the pulsed jet impact force increases with the increase of driving pressure, but decreases with the increase of ambient pressure and standoff distance; the inspiratory capacity increases as driving pressure increases,at a speed varying according to the stimulus of ambient pressure ,and becomes stable gradually; start-up inspiratory pressure increases as ambient pressure increases,exhibiting certain regularity. The experiment provides basis for the in-depth study on self-excited inspiratory pulsed jet and its application in projects like reservoir desilting.%针对深水水库泥沙处理技术问题和需求的迫切性,运用自行研制的试验装置对不同围压(模拟不同水深)下的自激吸气式脉冲射流装置性能进行了试验,研究分析了工作压力、围压、靶距对脉冲射流冲击力的影响,并对装置吸气量的变化及启动吸气压力进行了初步分析.结果表明,脉冲射流冲击力随工作压力的增加而增大,随围压和靶距的增加而减小;装置吸气量随工作压力的增加而增大,增大的速度随围压的不同而不同,并逐渐趋于稳定;启动吸气压力随围压增加而增大,且表现出一定规律性.研究结果为进一步深入研究自激吸气式脉冲射流及其在水库清淤等工程应用方面提供依据.

  20. Calibration and Maintenance of Blood Pressure Monitor in Metrological Verification%计量检定中血压计的检定与维修保养

    Institute of Scientific and Technical Information of China (English)

    顾晓森

    2015-01-01

    血压是人体的重要生理参数,是人们了解人体生理状况的重要指标。测量血压的仪器称为血压计,血压计分为水银式血压计、气压表式血压计、电子血压计三种。本文通过分析介绍上述三种血压计,发现水银柱式血压计测量的准确性和稳定性最高,应大力推广和应用水银柱式血压计。%Blood pressure is one of the important physiological parameters, and it is the important physiology index to understand people’s physical activities. The measuring instrument for blood pressure is named blood pressure monitor. Blood pressure monitor is divided into mercury sphygmomanometer, gauge type sphygmomanometer and electronic sphygmomanometer. Through analyzing the above three kinds of sphygmomanometer, this paper finds that the accuracy and stability of mercury column type sphygmomanometer is highest. Mercury column type sphygmomanometer should be energetically popularized and applied.

  1. 原发性高血压患者动态脉压与靶器官损害的观察%Clinical investgation between pulse pressure of primary hypertention and target organ damages

    Institute of Scientific and Technical Information of China (English)

    方东升; 袁俊强

    2011-01-01

    Objective To explore the correlation between the pulse pressure of primary hypertention and target organ damages(Intima -media thickness,left ventricular mass index and renal features). Methods Totally 150 patients diagnosed primary hypertention were assigned 3 groups according to the level of pulse pressures:the pulse pressure is below 60mm Hg,between 60 ~80mm Hg and above 80mm Hg. All of the select candidates,were taken color ultrasound of cervical arteries ang renal features, we record the Intima - media thickness(IMT) of cervical arteries ,left ventricular mass index(LVMI). Results The IMT,LV-MI and renal creatinine raised graduately accompying the level of pulse pressure (P <0.05). Conclusions There were larger corrrlation between the pulse pressure of primary hypertention and target organ damages (Intima - media thickness, left ventricular mass index and renal features) , therefore pulse pressure was a promising indicator in forecasting IMT, LVMI and renal features.%目的 探讨动态脉压与靶器官如颈动脉内膜中层厚度(IMT)、左心室重量指数(LVMI)、血肌酐的相关性.方法 将150例高血压患者根据动态脉压不同分组:Ⅰ组,动态脉压≤60mm Hg;Ⅱ组,动态脉压60~80mm Hg;Ⅲ组,动态脉压>80mm Hg;对所有入选者行颈动脉超声、心脏超声和血肌酐测定.结果 3组原发性高血压患者IMT、LVMI和血肌酐随动态脉压的升高而显著增加,P<0.05.结论 脉压是IMT、左心室肥厚等靶器官的重要危险因素.

  2. Sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy setup for pulsed and constant wave X-ray light sources.

    Science.gov (United States)

    Shavorskiy, Andrey; Neppl, Stefan; Slaughter, Daniel S; Cryan, James P; Siefermann, Katrin R; Weise, Fabian; Lin, Ming-Fu; Bacellar, Camila; Ziemkiewicz, Michael P; Zegkinoglou, Ioannis; Fraund, Matthew W; Khurmi, Champak; Hertlein, Marcus P; Wright, Travis W; Huse, Nils; Schoenlein, Robert W; Tyliszczak, Tolek; Coslovich, Giacomo; Robinson, Joseph; Kaindl, Robert A; Rude, Bruce S; Ölsner, Andreas; Mähl, Sven; Bluhm, Hendrik; Gessner, Oliver

    2014-09-01

    An apparatus for sub-nanosecond time-resolved ambient-pressure X-ray photoelectron spectroscopy studies with pulsed and constant wave X-ray light sources is presented. A differentially pumped hemispherical electron analyzer is equipped with a delay-line detector that simultaneously records the position and arrival time of every single electron at the exit aperture of the hemisphere with ~0.1 mm spatial resolution and ~150 ps temporal accuracy. The kinetic energies of the photoelectrons are encoded in the hit positions along the dispersive axis of the two-dimensional detector. Pump-probe time-delays are provided by the electron arrival times relative to the pump pulse timing. An average time-resolution of (780 ± 20) ps (FWHM) is demonstrated for a hemisphere pass energy E(p) = 150 eV and an electron kinetic energy range KE = 503-508 eV. The time-resolution of the setup is limited by the electron time-of-flight (TOF) spread related to the electron trajectory distribution within the analyzer hemisphere and within the electrostatic lens system that images the interaction volume onto the hemisphere entrance slit. The TOF spread for electrons with KE = 430 eV varies between ~9 ns at a pass energy of 50 eV and ~1 ns at pass energies between 200 eV and 400 eV. The correlation between the retarding ratio and the TOF spread is evaluated by means of both analytical descriptions of the electron trajectories within the analyzer hemisphere and computer simulations of the entire trajectories including the electrostatic lens system. In agreement with previous studies, we find that the by far dominant contribution to the TOF spread is acquired within the hemisphere. However, both experiment and computer simulations show that the lens system indirectly affects the time resolution of the setup to a significant extent by inducing a strong dependence of the angular spread of electron trajectories entering the hemisphere on the retarding ratio. The scaling of the angular spread with

  3. 老年高血压患者脉压和心电图变化%Changes of Pulse Pressure and Electrocardiogram in the Eldetly with High Blood Pressure

    Institute of Scientific and Technical Information of China (English)

    孙箫音; 陈芳; 裴大军

    2013-01-01

    目的:分析老年高血压患者脉压(PP)与心电图变化.方法:对291名老年高血压患者进行基本信息调查,并进行血压与心电图的测量,分析不同PP患者血压现状和心电图异常的差异.结果:在老年高血压患者中,1期高血压所占比例最大,为68.73%,86.95%的高血压患者PP值偏高,1期和2期高血压患者中,PP在41~60mmHg者所占比例最高,3期高血压患者中,PP>61mmHg者所占比例最高,且明显高于1期和2期高血压患者,差异均有统计学意义(P<0.05或P<0.01).PP≥61mmHg组患者各种心电图异常率均高于PP≤40mmHg组(心律失常除外)和PP在40~60mmHg组(左室高电压除外),差异有统计学意义(P<0.05或P<0.01).结论:高血压患者PP值普遍偏高,PP增加可加重心电图异常发生率,监测PP并行有效干预有助于预防心血管事件的发生.%Objective: To explore the relationship between pulse pressure(PP) and ECG for the elderly with high blood pressure. Method: The current situation and relationship were analysed by the basic information of the investigation, and blood pressure and electrocardiogram in 291 elderly with high blood pressure were measured. Results: Hypertension accounted for 68. 73% of the total population hypertension in elderly patients with high blood pressure, PP for the most hypertension patients was high, accounted for 86. 59%. The difference of PP and high blood pressure were significant(P<0. 05 or P<0. 01). With the increase of PP, ECG abnormal rate was increased. Conclusion: PP of the most hypertension patients is high. There is a close contact in PP and ECG, especially the PP is an important factor in cardiovascular disease. PP monitoring and effective intervention con be helpful to prevent the occurrence of cardiovascular events.

  4. PULSE AMPLITUDE DISTRIBUTION RECORDER

    Science.gov (United States)

    Cowper, G.

    1958-08-12

    A device is described for automatica1ly recording pulse annplitude distribution received from a counter. The novelty of the device consists of the over-all arrangement of conventional circuit elements to provide an easy to read permanent record of the pulse amplitude distribution during a certain time period. In the device a pulse analyzer separates the pulses according to annplitude into several channels. A scaler in each channel counts the pulses and operates a pen marker positioned over a drivable recorder sheet. Since the scalers in each channel have the sanne capacity, the control circuitry permits counting of the incoming pulses until one scaler reaches capacity, whereupon the input is removed and an internal oscillator supplies the necessary pulses to fill up the other scalers. Movement of the chart sheet is initiated wben the first scaler reaches capacity to thereby give a series of marks at spacings proportional to the time required to fill the remaining scalers, and accessory equipment marks calibration points on the recorder sheet to facilitate direct reading of the number of external pulses supplied to each scaler.

  5. Mercury Calibration System

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Joseph Rovani; Mark Sanderson; Ryan Boysen; William Schuster

    2009-03-11

    U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The qualification section describes in general terms tests that must be conducted by the calibrator vendors to demonstrate that their calibration equipment meets the minimum requirements to be established by EPA for use in CAMR monitoring. Variables to be examined include linearity, ambient temperature, back pressure, ambient pressure, line voltage, and effects of shipping. None of the procedures were described in detail in the draft interim documents; however they describe what EPA would like to eventually develop. WRI is providing the data and results to EPA for use in developing revised experimental procedures and realistic acceptance criteria based on

  6. Association of Pulse Pressure, Arterial Elasticity, and Endothelial Function With Kidney Function Decline Among Adults With Estimated GFR > 60 mL/min/1.73 m2: The Multi-Ethnic Study of Atherosclerosis

    Science.gov (United States)

    Peralta, Carmen A.; Jacobs, David R.; Katz, Ronit; Ix, Joachim H.; Madero, Magdalena; Duprez, Daniel A.; Sarnak, Mark J.; Criqui, Michael H.; Kramer, Holly J.; Palmas, Walter; Herrington, David; Shlipak, Michael G.

    2011-01-01

    Background The association of subclinical vascular disease and early declines in kidney function has not been well studied. Study Design Prospective cohort study Setting & Participants MESA participants with eGFR ≥60 ml/min/1.73m2 with follow-up of 5 years Predictors Pulse pressure (pulse pressure), small and large arterial elasticity (SAE, LAE), and flow mediated dilation. Outcomes kidney function decline Measurements SAE and LAE were measured by pulse contour analysis of the radial artery. Kidney function was measured by serum creatinine- and cystatin C-based eGFR. Results Among 4,853 adults, higher pulse pressure and lower SAE and LAE had independent and linear associations with faster rates of kidney function decline. Compared to persons with pulse pressure 40–50mmHg, eGFRSCysC decline was 0.29 (p=0.006), 0.56 (p70mmHg, respectively. Compared to the highest quartile of SAE (most elastic), eGFRSCysC decline was 0.26 (p=0.009), 0.35 (p=0.001), and 0.70 (p<0.001) ml/min/1.73m2/year faster for the second, third and fourth quartiles respectively. For LAE, compared to the highest quartile, eGFRSCysC decline was 0.28 (p=0.004), 0.58 (p<0.001), and 0.83 (p<0.001) ml/min/1.73m2/year faster for each decreasing quartile of LAE. Findings were similar with creatinine-based eGFR. In contrast, among 2,997 adults with flow-mediated dilation and kidney function measures, flow-mediated dilation was not significantly associated with kidney function decline. For every 1-SD greater flow-mediated dilation, eGFRSCysC and eGFRSCr changed by 0.05 ml/min/1.73m2/year (p=0.3) and 0.06 ml/min/1.73m2/year (p=0.04), respectively. Limitations We had no direct measure of GFR, in common with nearly all large population based studies. Conclusions Higher pulse pressure and lower arterial elasticity, but not flow-mediated dilation, were linearly and independently associated with faster kidney function decline among persons with eGFR ≥60 ml/min/1.73m2. Future studies investigate whether

  7. A comparative study on the pulsed UV and the low-pressure UV inactivation of a range of microbial species in water.

    Science.gov (United States)

    Garvey, Mary; Thokala, Nikhil; Rowan, Neil

    2014-12-01

    Research into alternative methods of disinfecting water and wastewater has proven necessary due to the emergence of chlorine-resistant organisms and the disinfection byproducts associated with chlorine use. The use of UV light to inactivate microbial species has proven effective, however; standard UV lamps have proven to be less effective in their ability to inactivate parasites and bacterial endospores in water treatment settings. Pulsed UV (PUV) light may potentially provide a novel alternative to water and wastewater disinfection. Research outlined in this study assesses the potential of a novel PUV system for the rapid and reproducible inactivation of a range of test species including Bacillus endospores. In comparison to standard low-pressure (LP) UV lamps, this PUV system provided significantly higher levels of inactivation for all test species. Furthermore, there was a remarkable decrease in time needed to obtain significant inactivation rates following treatment with PUV compared to LP-UV. With the PUV system, a 70-second treatment time (7.65 μJ/cm2) resulted in similar inactivation rates of Bacillus endospores to that of the LP-UV inactivation of their vegetative counterpart. Also, at PUV doses exceeding 4.32 J/cm2, there was not a significant difference in the PUV inactivation of Bacillus endospores in the absence or presence of 10 ppm organic matter. However, the presence of organic matter resulted in a significant reduction in microbial inactivation for all treatment doses using the LP-UV system. The findings of this study suggest that PUV technology may provide a rapid effective method for the disinfection of water and wastewater.

  8. Temporal Behavior of the Pump Pulses, Residual Pump Pulses, and THz Pulses for D2O Gas Pumped by a TEA CO2 Laser

    Science.gov (United States)

    Geng, Lijie; Zhang, Zhifeng; Zhai, Yusheng; Su, Yuling; Zhou, Fanghua; Qu, Yanchen; Zhao, Weijiang

    2016-08-01

    Temporal behavior of the pump pulses, residual pump pulses, and THz pulses for optically pumped D2O gas molecules was investigated by using a tunable TEA CO2 laser as the pumping source. The pulse profiles of pump laser pulses, residual pump pulses, and the THz output pulses were measured, simultaneously, at several different gas pressures. For THz pulse, the pulse delay between the THz pulse and the pump pulse was observed and the delay time was observed to increase from 40 to 70 ns with an increase in gas pressure from 500 to 1700 Pa. Both THz pulse broadening and compression were observed, and the pulse broadening effect transformed to the compression effect with increasing the gas pressure. For the residual pump pulse, the full width at half maximum (FWHM) of the main pulse decreased with increasing gas pressure, and the main pulse disappeared at high gas pressures. The secondary pulses were observed at high gas pressure, and the time intervals of about 518 and 435 ns were observed between the THz output pulse and the secondary residual pump pulse at the pressure of 1400 Pa and 1700 Pa, from which the vibrational relaxation time constants of about 5.45 and 5.55 μs Torr were obtained.

  9. In-Flight Pitot-Static Calibration

    Science.gov (United States)

    Foster, John V. (Inventor); Cunningham, Kevin (Inventor)

    2016-01-01

    A GPS-based pitot-static calibration system uses global output-error optimization. High data rate measurements of static and total pressure, ambient air conditions, and GPS-based ground speed measurements are used to compute pitot-static pressure errors over a range of airspeed. System identification methods rapidly compute optimal pressure error models with defined confidence intervals.

  10. Pulse pressure is not an independent predictor of outcome in type 2 diabetes patients with chronic kidney disease and anemia--the Trial to Reduce Cardiovascular Events with Aranesp Therapy (TREAT)

    DEFF Research Database (Denmark)

    Theilade, S; Claggett, B; Hansen, T W

    2016-01-01

    Pulse pressure (PP) remains an elusive cardiovascular risk factor with inconsistent findings. We clarified the prognostic value in patients with type 2 diabetes, chronic kidney disease (CKD) and anemia in the Trial to Reduce cardiovascular Events with Aranesp (darbepoetin alfa) Therapy. In 4038......, CKD and anemia, PP did not independently predict cardiovascular events or ESRD. This may reflect confounding by aggressive antihypertensive treatment, or PP may be too rough a risk marker in these high-risk patients....

  11. 120kV下常压空气纳秒脉冲电晕放电特性%Characteristic of nanosecond-pulsed corona discharge at 120 kV in atmospheric-pressure air

    Institute of Scientific and Technical Information of China (English)

    章程; 邵涛; 许家雨; 马浩; 徐蓉; 严萍

    2012-01-01

    With an excitation of negative repetitive pulses of 15 ns rise time and 30 to 40 ns duration, corona discharge in nanosecond-pulse regime at 120 kV in atmospheric-pressure air is experimentally investigated, and the characteristic of nanosecond-pulsed corona discharge is analyzed by the measurement of electrical discharge parameters, images and X-ray emission. The results show that X-ray emission occurs in nanosecond-pulsed corona discharge, but the intensity is weak. The counts of X rays decrease with the air gap spacing but increase with the pulse repetition frequency. In addition, owing to the fact that the residual particles in the gap enhance the local electric field when the next pulse is applied, separated corona channels are easily obtained at high pulse repetition frequency.%使用上升沿15 ns、脉宽30~40 ns的重复频率纳秒脉冲电源对120 kV下大气压空气中管-板电极结构电晕放电进行了实验研究,通过电压电流测量、放电图像拍摄和X射线探测分析了纳秒脉冲电晕放电特性.结果表明:纳秒脉冲电晕放电中存在X射线辐射,但辐射强度较弱,X射线辐射计数随着气隙距离的增大而减少,随着脉冲重复频率的增大而增多;放电空间的残余电荷加强了下一个脉冲到来时的局部电场,从而导致高重复频率下易于出现分散的电晕通道.

  12. A Simple Accelerometer Calibrator

    Science.gov (United States)

    Salam, R. A.; Islamy, M. R. F.; Munir, M. M.; Latief, H.; Irsyam, M.; Khairurrijal

    2016-08-01

    High possibility of earthquake could lead to the high number of victims caused by it. It also can cause other hazards such as tsunami, landslide, etc. In that case it requires a system that can examine the earthquake occurrence. Some possible system to detect earthquake is by creating a vibration sensor system using accelerometer. However, the output of the system is usually put in the form of acceleration data. Therefore, a calibrator system for accelerometer to sense the vibration is needed. In this study, a simple accelerometer calibrator has been developed using 12 V DC motor, optocoupler, Liquid Crystal Display (LCD) and AVR 328 microcontroller as controller system. The system uses the Pulse Wave Modulation (PWM) form microcontroller to control the motor rotational speed as response to vibration frequency. The frequency of vibration was read by optocoupler and then those data was used as feedback to the system. The results show that the systems could control the rotational speed and the vibration frequencies in accordance with the defined PWM.

  13. Analysis of arc pressure and its weld quality in hybrid ultra-high frequency pulse VP-GTAW process%HPVP-GTAW电弧力及焊接质量分析

    Institute of Scientific and Technical Information of China (English)

    从保强; 齐铂金; 杨明轩; 李伟; 王乐笑; 杨舟; 李玉龙

    2013-01-01

    分别以3种不同材质铝合金平板材料为试验对象,研究分析了复合超高频脉冲方波变极性钨极氩弧焊接(HPVP-GTAW)过程中电弧力的变化及其对焊缝成形特征和接头力学性能的影响.结果表明,与常规变极性氩弧焊工艺相比,脉冲方波电流的加入使得HPVP-GTAW电弧力显著增加,同时焊缝熔透率大幅提高,接头力学性能得到明显改善和提高;保持脉冲电流幅值和占空比基本不变,在10~80 kHz范围内,脉冲电流频率对焊接过程产生了重要影响,频率为40 kHz时,HPVP-GTAW电弧力和焊缝熔透率均达到最大,分别约为常规变极性焊接电弧的1.9倍和1.7倍.%The variations of arc pressure and weld characteristics in the welding of 2219, 2A14 and 5A06 aluminum alloys were investigated based on the hybrid ultrahigh frequency pulse current variable polarity gas tungsten arc welding ( HPVP-GTAW) process. The experimental results show that compared with the conventional VP-GTAW ( variable polarity gas tungsten arc welding) process, arc pressure and weld penetration expressed by the ratio of weld depth to width are enhanced predominantly with the effect of high frequency pulse current. Mechanical properties of welded joints are improved obviously. At the given pulse current amplitude and pulse duty cycle, the welding process is influenced significantly by the pulse current frequency in the range of 10 kHz to 80 kHz. At the given pulse frequency of 40 kHz, arc pressure and weld penetration of welded joints increased by about 90% and 70% , respectively, compared with that of welded joints with no effect of pulse current.

  14. Mercury Continuous Emmission Monitor Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Ryan Boysen; William Schuster; Joseph Rovani

    2009-03-12

    /mass spectrometry (ID/ICP/MS) performed by NIST in Gaithersburg, MD. The outputs of mercury calibrators are compared to one another using a nesting procedure which allows direct comparison of one calibrator with another at specific concentrations and eliminates analyzer variability effects. The qualification portion of the EPA interim traceability protocol requires the vendors to define calibrator performance as affected by variables such as pressure, temperature, line voltage, and shipping. In 2007 WRI developed and conducted a series of simplified qualification experiments to determine actual calibrator performance related to the variables defined in the qualification portion of the interim protocol.

  15. 高龄老年人脉压差、血脂、血糖关系分析%Analysis of the Correlation between Pulse Pressure,Blood Lipid,Blood Sugar in the Elderly People

    Institute of Scientific and Technical Information of China (English)

    丁翊; 刘芳

    2013-01-01

    Objective:Removed the age factor, to probe into the correlation between blood pressure,blood lipid,blood sugar and arteriosclerosis in the elderly people. Methods:Analyzed the correlation between Pulse Pressure,Mean Arterial blood pressure and Diabetes mellitus,Hypertension in 279 examination of the elderly. analyzed the changes of blood glucose,blood lipid at the different levels of Pulse Pressure. In order to know the correlation between Pulse Pressure,Mean Arterial blood pressure and blood glucose,blood lipid, blood pressure. Results:There was a correlation between arteriosclerosis and arterial compliance in the elderly people and hyperglycemia,the disorder of lipid metabolism and high systolic blood pressure. Conclusions:Strengthened the blood glucose management and the treatment of dyslipidemia in patients with diabetes mellitus, strengthened the control of blood pressure in patients with essential hypertension, these measures had a positive effect on prevention and treatment of senile arteriosclerosis.%目的:探讨老年动脉硬化除去年龄因素以外与血压、血糖、血脂的关系。方法:体检的老年人279例,分析脉压、平均动脉压与糖尿病、高血压病的关系及不同脉压水平下血糖、血脂的变化,进一步了解脉压、平均动脉压与血糖、血脂、血压之间的关系。结果:高龄老年人动脉硬化、血管顺应性减低与血糖增高、血脂代谢紊乱、收缩压增高有关。结论:加强糖尿病患者的血糖管理及血脂紊乱的治疗、加强高血压病患者血压控制对老年动脉硬化的防治有积极作用。

  16. Relationship between Pulsed High Intensity Focused Ultrasound Parameter Setting and Focal Zone Acoustic Pressure%脉冲高强度聚焦超声参数设置与焦点声压的关系

    Institute of Scientific and Technical Information of China (English)

    史学豹; 赵纯亮; 宋柯; 王华

    2012-01-01

    Pulsed high intensity focused ultrasound have potential advantages in guaranteeing accuracy and operation controllability during ultrasound treatment,it is an urgent problem to study the relationship between different pulse parameter setting and focal zone acoustic pressure, especially after cavitation bubbles appeared.Using audio-optical deflection method, this paper proposes the measurements results of focal zone acoustic pressure of different pulse widths and intervals setting under increasing input voltages,and meanwhile compare the results with CW insonation.It is show,n that when pulse width longer than 1 ms, the regularity of focal zone acoustic pressure changing with input voltage of different pulse parameter settings in accord with each other.After cavitation bubbles appeared, the focal zone acoustic pressure continue rising with the increasing input voltage and reaches a maximum value,when vast cavitation bubbles appeared,the focal zone acoustic pressure decreases.%脉冲高强度聚焦超声(PHIFU)对于提高治疗精确性和操作可控性具有潜在优势,PHIFU辐照过程中不同脉冲宽度及占空比的设置对焦点声压、空化现象出现后焦区声压的具体影响,成为目前迫切需要研究的问题.基于此,本文通过声光折射法测量了脉冲宽度为1 ms、10 ms、100 ms,脉冲间隔分别为100 ms、200 ms、500 ms、1000 ms时焦点声压随输入电压的变化数据,并与连续 波辐照下的数据进行对比,结果显示在脉冲大于1 ms时,不同脉冲参数的焦点声压随电压变化规律一致,空化现象出现后焦点声压仍会继续升高并达到极值,空化气泡大量出现后焦区声压下降.

  17. The Independent and Joint Association of Blood Pressure, Serum Total Homocysteine, and Fasting Serum Glucose Levels With Brachial-Ankle Pulse Wave Velocity in Chinese Hypertensive Adults.

    Science.gov (United States)

    Liu, Xiaoyun; Sun, Ningling; Yu, Tao; Fan, Fangfang; Zheng, Meili; Qian, Geng; Wang, Binyan; Wang, Yu; Tang, Genfu; Li, Jianping; Qin, Xianhui; Hou, Fanfan; Xu, Xiping; Yang, Xinchun; Chen, Yundai; Wang, Xiaobin; Huo, Yong

    2016-09-28

    This study aimed to investigate the independent and joint association of blood pressure (BP), homocysteine (Hcy), and fasting blood glucose (FBG) levels with brachial-ankle pulse wave velocity (baPWV, a measure of arterial stiffness) in Chinese hypertensive adults.The analyses included 3967 participants whose BP, Hcy, FBG, and baPWV were measured along with other covariates. Systolic BP (SBP) was analyzed as 3 categories (SBP < 160 mmHg; 160 to 179 mmHg; ≥ 180 mmHg); Hcy as 3 categories (< 10 μmol/L; 10 to 14.9 μmol/L; ≥ 15.0 μmol/L) and FBG: normal (FBG < 5.6 mmol/L), impaired (5.6 mmol/L ≤ FBG < 7.0 mmol/L), and diabetes mellitus (FBG ≥ 7.0 mmol/L). We performed linear regression analyses to evaluate their associations with baPWV with adjustment for covariables.When analyzed individually, BP, Hcy, and FBG were each associated with baPWV. When BP and FBG were analyzed jointly, the highest baPWV value (mean ± SD: 2227 ± 466 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and SBP ≥ 180 mmHg (β = 432.5, P < 0.001), and the lowest baPWV value (mean ± SD: 1692 ± 289 cm/s) was seen in participants with NFG and SBP < 160 mmHg. When Hcy and FBG were analyzed jointly, the highest baPWV value (2072 ± 480 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and Hcy ≥ 15.0 μmol/L (β = 167.6, P < 0.001), while the lowest baPWV value (mean ± SD: 1773 ± 334 cm/s) was observed in participants with NFG and Hcy < 10 μmol/L.In Chinese hypertensive adults, SBP, Hcy, and FBG are individually and jointly associated with baPWV.Our findings underscore the importance of identifying individuals with multiple risk factors of baPWV including high SBP, FBG, and Hcy.

  18. Characteristics of nanosecond-pulse atmospheric pressure plasma jet%纳秒脉冲放电等离子体射流特性

    Institute of Scientific and Technical Information of China (English)

    牛铮; 邵涛; 章程; 方志; 李春霞; 张东东; 严萍

    2012-01-01

    In the experiments, with the use of a single needle electrode, atmospheric pressure plasma jets are excited by a repetitive unipolar nanosecond-pulse generator, with working gases such as helium, argon, nitrogen and air. The results show that the jet length increases with the rise of applied voltages as the flow rate of working gas increases, the length of jet becomes gradually longer and then reduces gradually to saturation after a certain flow rate due to turbulence. In addition, the plasma jets of different working gases have very different appearances. Helium and argon gas jets are needle-like, and the longest jet length is o-ver 7 cm: whereas in nitrogen and in air, the jet is no more than 2 cm long, of brush-like mode.%采用单针式电极,使用单极性重复频率脉冲电源,在常压氦气、氩气、氮气和空气中得到等离子体射流,并改变电压、流量和气体种类,分别观察不同的实验条件对等离子体射流的影响.实验结果表明:射流长度随施加电压的增加而增长;随着流量的连续变化,射流长度先逐渐变长,达到峰值后由于湍流影响,长度又逐渐缩短,达到一定流量后趋于饱和.此外,不同工作气体中的等离子体射流呈现截然不同的外观,氦气和氩气中射流呈针状模式,长度可达7 cm以上;而在氮气和空气中,射流呈现为长度不超过2 cm的刷状模式.

  19. Central and peripheral blood pressures in relation to plasma advanced glycation end products in a Chinese population.

    Science.gov (United States)

    Huang, Q-F; Sheng, C-S; Kang, Y-Y; Zhang, L; Wang, S; Li, F-K; Cheng, Y-B; Guo, Q-H; Li, Y; Wang, J-G

    2016-07-01

    We investigated the association of plasma AGE (advanced glycation end product) concentration with central and peripheral blood pressures and central-to-brachial blood pressure amplification in a Chinese population. The study subjects were from a newly established residential area in the suburb of Shanghai. Using the SphygmoCor system, we recorded radial arterial waveforms and derived aortic waveforms by a generalized transfer function and central systolic and pulse pressure by calibration for brachial blood pressure measured with an oscillometric device. The central-to-brachial pressure amplification was expressed as the central-to-brachial systolic blood pressure difference and pulse pressure difference and ratio. Plasma AGE concentration was measured by the enzyme-linked immunosorbent assay method and logarithmically transformed for statistical analysis. The 1051 participants (age, 55.1±13.1 years) included 663 women. After adjustment for sex, age and other confounding factors, plasma AGE concentration was associated with central but not peripheral blood pressures and with some of the pressure amplification indexes. Indeed, each 10-fold increase in plasma AGE concentration was associated with 2.94 mm Hg (P=0.04) higher central systolic blood pressure and 2.39% lower central-to-brachial pulse pressure ratio (P=0.03). In further subgroup analyses, the association was more prominent in the presence of hypercholesterolemia (+8.11 mm Hg, P=0.008) for central systolic blood pressure and in the presence of overweight and obesity (-4.89%, P=0.009), diabetes and prediabetes (-6.26%, P=0.10) or current smoking (-6.68%, P=0.045) for central-to-brachial pulse pressure ratio. In conclusion, plasma AGE concentration is independently associated with central systolic blood pressure and pulse pressure amplification, especially in the presence of several modifiable cardiovascular risk factors.

  20. Formation of Dielectric Barrier Multi-Pulse Glow Discharges in Helium at Atmospheric Pressure%大气压氦气介质阻挡多脉冲辉光放电的形成条件

    Institute of Scientific and Technical Information of China (English)

    郝艳捧; 王晓蕾; 阳林

    2009-01-01

    Discharge currents are measured on single pulse, multi-pulse glow dielectric barrier discharges (DBDs) using high-frequency power supply in helium at atmospheric pressure. The influence of the applied voltage amplitude and frequency, as well as gas distance on multi-pulse glow DBD is discussed and analyzed. Conditions to form multi-pulse glow DBDs are proposed. The results show that the higher amplitude of the applied voltage, the lower voltage frequency can be useful to form a multi-pulse glow DBD. Moreover, the higher applied voltage is necessary to form multi-pulse glow DBDs.%利用高频高压电源,进行大气压氦气介质阻挡放电试验,测量了单脉冲和多脉冲辉光放电的放电回路电流波形,分析了外加电压峰.峰值和频率、放电间隙对多脉冲辉光放电过程的影响,探讨了大气压氦气介质阻挡多脉冲辉光放电的形成条件.研究表明:多脉冲辉光放电的形成条件是较高的外加电压峰-峰值、较低的电源频率,其中较高的外加电压峰-峰值是产生多脉冲辉光放电的必要条件.

  1. 基于容积脉搏波的无创连续血压测量系统%A Non-invasive Continuous Blood Pressure Measurement System Based on Plethysmographic Pulse Wave

    Institute of Scientific and Technical Information of China (English)

    梁永波; 陈真诚; 朱健铭; 殷世民

    2013-01-01

    Objective To develop a non-invasive continuous blood pressure measurement system without the cuff based on plethysmographic pulse wave. Methods A blood pressure estimation equation was established by the stepwise regression analysis on blood pressure and pulse wave transit time which was extracted from a single circle of plethysmographic pulse wave, and then the non-invasive continuous blood pressure measurement was realized. Results Compared blood pressure value with detection by the system and Yu-Yue brand mercury sphygmomanometer from various populations, the results indicated that the two methods exhibit good coherence , and the measurement error is better than the Association for the Advancement of Medical Instrumentation (AAMI) recommendation standard. Conclusion Compared with traditional blood pressure measurement method , the non-invasive continuous blood pressure measurement method is more convenient. It can measure blood pressure continuously without cuff and invasion, and may have promising application in the future.%目的 设计一种基于容积脉搏波的无袖套连续血压测量系统.方法 从单一容积脉搏波中提取脉搏波传导时间,经逐步回归分析与血压建立血压估算方程,实现无创连续血压测量.结果 通过对不同人群血压检测,并与鱼跃牌水银血压计进行对比,结果表明该方法和传统方法具有较好的测试一致性,测量误差优于美国医疗仪器促进协会(AAMI)推荐标准.结论 该方法同传统血压测量方法相比,测量方便,可彻底摆脱缚带,并能实现无创连续测量,具有更广阔的应用前景.

  2. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina

    2016-05-02

    This poster presents the development, implementation, and operation of the Broadband Outdoor Radiometer Calibrations (BORCAL) Longwave (LW) system at the Southern Great Plains Radiometric Calibration Facility for the calibration of pyrgeometers that provide traceability to the World Infrared Standard Group.

  3. Effect of oxygen partial pressure on the magnetic properties of La2/3Sr1/3MnO3 films grown on SrTiO3 (1 1 1) substrates by pulsed laser deposition

    Science.gov (United States)

    Prajapat, C. L.; Kalita, Parswajit; Sastry, P. U.; Singh, M. R.; Gupta, S. K.; Ravikumar, G.

    2014-09-01

    The influence of oxygen partial pressure on phase formation and magnetic properties of LSMO (La2/3Sr1/3MnO3) thin films deposited on STO (1 1 1) substrates by pulsed laser deposition was investigated. Phase formation and epitaxial growth were confirmed by X-ray diffraction. Good crystalline mosaic is observed for oxygen partial pressures ranging from 0.3 to 1.0 mbar. For each of the pressures, the lattice parameters were estimated assuming the lattice distortion is volume conserving. The Curie temperatures TC vs lattice strain relation thus obtained is comparable to the available data in literature. Variation in coercive field of the films can be accounted for by the variation in TC.

  4. Calibration of sound calibrators: an overview

    Science.gov (United States)

    Milhomem, T. A. B.; Soares, Z. M. D.

    2016-07-01

    This paper presents an overview of calibration of sound calibrators. Initially, traditional calibration methods are presented. Following, the international standard IEC 60942 is discussed emphasizing parameters, target measurement uncertainty and criteria for conformance to the requirements of the standard. Last, Regional Metrology Organizations comparisons are summarized.

  5. An Instrument for Testing Pulse Signals Based on Thin Film Pressure Sensor%基于薄膜压力传感器的脉搏信号测试系统

    Institute of Scientific and Technical Information of China (English)

    邹建; 钱波; 卢平; 应苑松

    2011-01-01

    人体脉搏信号携带有丰富的与健康相关的生理信息.为了方便脉搏信号的采集和研究,本文设计出一种采用轻触式薄膜按键面板工艺的自制脉搏压力传感器,并使用了常见的555和V-f转换器件将传感器压力信号转换为电信号,再通过后续设计的滤波、陷波放大电路以及电路的干扰抑制处理,系统就可以获取高质量的脉搏波信号.传感器的性能测试以及示波器的应用结果表明,基于薄膜压力传感器的脉搏信号测试系统工作性能稳定,并通过示波器的串口通信扩展模块或者LABVIEW采集卡可以在计算机上显示出采集的脉搏信号,此测试系统可用于脉象信息的采集与研究.%The pulse wave signals contain plenty of information which conveys the health status of human body. To acquire and analyze the pulse signals, we developed a kind of pressure sensors, by adopting soft-touch metal dome craftsmanship. The oscillator amplifier 555 and V-f conversion circuit were utilized to transform the pressure signals into electric signals Then the system effectively acquired the pulse signals by following filter circuit, band stop circuit, amplifier circuit and the method of interference. Experiments of performance test to pressure sensor and oscilloscope proved that the test system based on thin film pressure sensor had reliable performance and could be used to study the pulse wave by the collected pulse signals shown on the computer through the serial communication expansion module of the oscilloscope or the data acquisition card of LABVIEW.

  6. Retinal vascular calibres are significantly associated with cardiovascular risk factors

    DEFF Research Database (Denmark)

    von Hanno, T.; Bertelsen, G.; Sjølie, Anne K.;

    2014-01-01

    ) and retinal venular calibre (central retinal vein equivalent) were measured computer-assisted on retinal photographs. Data on blood pressure, body mass index (BMI), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, glycosylated haemoglobin (HbA1c) and smoking were collected...... only. Blood pressure had the strongest effect on arteriolar calibre, with a decrease in calibre of 3.6m (women)/4.1m (men) per standard deviation increase in mean arterial blood pressure. Retinal venular calibre was independently associated with age, blood pressure, BMI, HDL and LDL cholesterol....... Association between retinal vessel calibre and the cardiovascular risk factors was assessed by multivariable linear and logistic regression analyses. Results: Retinal arteriolar calibre was independently associated with age, blood pressure, HbA1c and smoking in women and men, and with HDL cholesterol in men...

  7. Effect of O{sub 2} partial pressure on YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin film growth by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Haugan, T.; Barnes, P.N.; Brunke, L.; Maartense, I.; Murphy, J

    2003-10-01

    YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films were processed by pulsed laser deposition on (1 0 0) LaAlO{sub 3} substrates using O{sub 2} partial pressures from 120 to 1200 mTorr. The effect of O{sub 2} pressure on film properties including room temperature resistivities and microstructures was studied for a unique set of deposition parameters. The film quality was observed to remain high over a wide range of O{sub 2} partial pressures, with much less sensitivity to O{sub 2} pressure than previous studies which are compared. For O{sub 2} pressures from 200 to 1200 mTorr, superconducting transition temperatures consistently reached values >91.5 K and transport critical current densities were 3-5 MA/cm{sup 2} (77 K, self-field). It is proposed that less sensitivity of film properties to O{sub 2} pressure is achieved by: (1) reducing the particle velocity of the plume below a critical threshold, and (2) using a deposition temperature of 785 deg. C for adequate surface activation.

  8. 老年人动态脉压及脉压指数与颈动脉内膜中层厚度的相关性分析%Relationship between ambulatory pulse pressure,pulse pressure index and carotid intima media thickness in old subjectss

    Institute of Scientific and Technical Information of China (English)

    何佳; 唐海沁

    2013-01-01

    目的 探讨老年人动态脉压及脉压指数与颈动脉内膜中层厚度的关系.方法 随机抽样调查65岁以上人群200人进行24h动态血压监测,监测患者的动态脉压(APP)水平,按APP≤40 mm Hg(46例)、41 ~60 mm Hg(66例)、61~80 mm Hg(61例)和>80 mm Hg(27例)分为4组;按动态脉压指数(APPI)≤0.40(49例)、0.41 ~0.50(70例)、0.51 ~0.60(57例)和>0.60(24例)分为4组.分别以彩色多普勒超声测定其颈动脉内膜中层厚度(IMT),并采集其静脉血测定血脂及高敏C-反应蛋白(hs-CRP).结果 随着APP及APPI的增加,颈动脉IMT明显增加,差异有统计学意义(P<0.05);Spearman相关分析,结果APP、APPI与颈动脉IMT呈正相关,其中以APPI相关系数(r)值大.结论 动态脉压及脉压指数与颈动脉内膜中层厚度密切相关,且脉压指数在一定程度上较脉压在动脉硬化发展上有更大相关性.%Objective To investigate the correlation of ambulatory pulse pressure (APP) and ambulatory pulse pressure index(APPI) with intima-media thickness(IMT) of carotid artery in old people.Methods To evaluate the value of APP and APPI within 24 hours in 200 senile patients chosen at random who are over 65 years old,whose PP and PPI level were measured by the dynamic blood pressure(BP) monitor.Those senile patients were divided into 4 groups based on APP level,as APP ≤ 40 mmHg(46 cases),41-60 mmHg(66 cases),61-80 mmHg(61 cases) and APP > 80 mmHg(27 cases).These cases were also further divided into 4 groups based on APPI level,as APPI≤0.40(49 cases),0.41-0.50(70 cases),0.51-0.60(57 cases),and APPI >0.60(24 cases).Intima-media thickness(IMT) of carotid artery,serum lipid and hs-CRP concentration were determined by Color Doppler Ultrasonography and immune turbidimetric assay,respectively.Results With the increase of APP and APPI,carotid IMT increased significantly,the difference was statistically significant (P < 0.05).Spearman correlation analysis showed that APP

  9. Pressure Drop Measurement of Column Weight in Disc and Doughnut Pulsed Extraction Column by External Air Purge Method%外置吹气杯测量折流板脉冲萃取柱柱重压降

    Institute of Scientific and Technical Information of China (English)

    王悦云; 李少伟; 景山

    2013-01-01

    The pressure drop of column weight was measured in a disc and doughnut pulsed extraction column with the inertial diameter of 0.3 m and height of 5.6 m by in-ternal and external air purge methods ,respectively .The experimental results show that the pressure drops of column weight measured by external air purge method are in good agreement with those by internal air purge method ,therefore ,the external air purge method is recommended to measure the pressure drop of column weight in the pulsed extraction column in plutonium purification cycle .%在内径为0.3m和高度为5.6m的折流板脉冲萃取柱中,分别采用内置吹气杯和外置吹气杯对柱重压降信号进行了测量和比较。实验结果表明,两种吹气杯安装方式所测量的结果一致。因此,为了避免由于内置吹气杯所造成的钚纯化循环脉冲萃取柱异形下澄清段的设计和加工难度,推荐可使用外置吹气杯来测量该工段的脉冲萃取柱柱重压降。

  10. NASA Glenn Icing Research Tunnel: Upgrade and Cloud Calibration

    Science.gov (United States)

    VanZante, Judith Foss; Ide, Robert F.; Steen, Laura E.

    2012-01-01

    In 2011, NASA Glenn s Icing Research Tunnel underwent a major modification to it s refrigeration plant and heat exchanger. This paper presents the results of the subsequent full cloud calibration. Details of the calibration procedure and results are presented herein. The steps include developing a nozzle transfer map, establishing a uniform cloud, conducting a drop sizing calibration and finally a liquid water content calibration. The goal of the calibration is to develop a uniform cloud, and to build a transfer map from the inputs of air speed, spray bar atomizing air pressure and water pressure to the output of median volumetric droplet diameter and liquid water content.

  11. A Calibrating Device for Rogowski Coil Development

    Institute of Scientific and Technical Information of China (English)

    LV Liang; LI Junhao; HUANG Jianjun; JI Shengchang; LI Yanming

    2007-01-01

    A calibrating device for the Rogowski coil is developed,which can be used to calibrate the Rogowski coil having a partial response time within tens of nanoseconds.Its key component is a step current generator,which can generate the output with a rise time of less than 2 ns and a duration of larger than 300 ns.The step current generator is composed by a pulse forming line(PFL)and a pulse transmission line(PTL).A TEM(transverse electromagnetic mode)coaxial measurement unit is used as PTL,and the coil to be calibrated and the referenced standard Rogowski coil can be fixed in the unit.The effect of the dimensions of the TEM unit is discussed theoretically as well as experimentally.

  12. Development of high-pressure, high-field and multifrequency electron spin resonance system.

    Science.gov (United States)

    Sakurai, T; Taketani, A; Tomita, T; Okubo, S; Ohta, H; Uwatoko, Y

    2007-06-01

    The electron spin resonance (ESR) system which covers the magnetic field region up to 16 T, the quasicontinuous frequency region from 60 to 700 GHz, the temperature region from 1.8 to 4.2 K, and the hydrostatic pressure region up to 1.1 GPa has been developed. This is the first pulsed high-field and multifrequency ESR system with the pressure region over 1 GPa as far as we know. Transmission ESR spectra under hydrostatic pressure can be obtained by combining a piston-cylinder-type pressure cell and the pulsed magnetic field ESR apparatus. The pressure cell consists of a NiCrAl cylinder and sapphire or zirconia inner parts. The use of sapphire or zirconia as inner parts enables us to observe ESR under pressure because these inner parts have high transmittance for the electromagnetic wave with millimeter and submillimeter wavelengths. We have successfully applied this system for the pressure dependence measurements of an isolated spin system NiSnCl(6)6H(2)O up to 1.1 GPa. It was found that the single ion anisotropy parameter D of this compound strongly depends on pressure. The parameter D is approximately proportional to the pressure up to 0.75 GPa, and the relation between D and the pressure can be used for the pressure calibration of this high-field and high-pressure ESR system.

  13. The influence of oxygen partial pressure on material properties of Eu{sup 3+}-doped Y{sub 2}O{sub 2}S thin film deposited by Pulsed Laser Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A.G., E-mail: aliag@qwa.ufs.ac.za [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Dejene, B.F. [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Swart, H.C. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300 (South Africa)

    2016-01-01

    Eu{sup 3+}-doping has been of interest to improve the luminescent characteristics of thin-film phosphors. Y{sub 2}O{sub 2}S:Eu{sup 3+} films have been grown on Si (100) substrates by using a Pulsed Laser Deposition technique. The thin films grown under different oxygen deposition pressure conditions have been characterized using structural and luminescent measurements. The X-ray diffraction patterns showed mixed phases of cubic and hexagonal crystal structures. As the oxygen partial pressure increased, the crystallinity of the films improved. Further increase of the O{sub 2} pressure to 140 mtorr reduced the crystallinity of the film. Similarly, both scanning electron microscopy and Atomic Force Microscopy confirmed that an increase in O{sub 2} pressure affected the morphology of the films. The average band gap of the films calculated from diffuse reflectance spectra using the Kubelka–Munk function was about 4.75 eV. The photoluminescence measurements indicated red emission of Y{sub 2}O{sub 2}S:Eu{sup 3+} thin films with the most intense peak appearing at 619 nm, which is assigned to the {sup 5}D{sub 0}–{sup 7}F{sub 2} transition of Eu{sup 3+}. This most intense peak was totally quenched at higher O{sub 2} pressures. This phosphor may be a promising material for applications in the flat panel displays.

  14. 负压区的存在对刚性陶瓷过滤器脉冲反吹性能的影响%EFFECT OF NEGATIVE PRESSURE REGION ON PULSE-JET CLEANING PERFORMANCE OF RIGID CERAMIC FILTERS

    Institute of Scientific and Technical Information of China (English)

    姬忠礼; 郭建光

    2000-01-01

    利用压电式压力传感器测定了陶瓷过滤器在脉冲反吹过程中滤管内动态压力的变化规律,表明在脉冲反吹快要结束和正常过滤尚未开始的过渡过程中,滤管内存在严重的负压区。利用单个颗粒轨道模型分析了部分已被吹离滤管表面的小颗粒在负压区的作用下会重新返回到滤管壁,从而证实了负压区是影响刚性陶瓷过滤器稳定运行的重要原因。%In a ceramic filter experimental set-up with three filter candles,the dynamic pressures atthe inner wall of one filter candle during pulse-jet cleaning aremeasured by using resize-electric pressure transducer. The experimentalresults show that the dynamic pressure in wholepulse-jet cleaning process consists of two parts. One is the positivepressure in the filter candlegreater than the pressure outside the filter candle whichcorresponds to the outward radial fluidflow to break up and dislodge the dust cake on the surfaceof the filter tube. The other is anegative pressure region which is responsible for inward radialflow while the pulse-jet is closed.The influences of reservoir pressure on thedynamic pressure are discussed.The calculation results of particle motion indicate that negativepressure region cause a fractionof particles removed re-deposit on the candle surface. Especiallyfiner particles is more easierlyre-deposited on the surface to form thin and dense layer on thefilter candle and to increasegradually the residual pressure drop across the candle. It isconcluded that negative pressureregion may have important effects on the long-term stable operation of thefilter unit.

  15. Assembly delay line pulse generators

    CERN Document Server

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  16. 老年人脉压与动脉粥样硬化的关系%Relationship between pulse pressure and artery atherosclerosis in elders

    Institute of Scientific and Technical Information of China (English)

    沈琪; 薛冰; 郝长宁; 丁东新; 石一沁; 高兴旺

    2009-01-01

    Objective To explore the relationship between pulse pressure (PP) and artery atherosclerosis in elders. Methods Totally 2358 eiders( > 60y) with the risk factors of artery atherosclerosis from Yangpu District DOI:10.3760/cma.j.issn.1008-6315.2009.09.006Central Hospital and 11 Community Health Service Centers were enrolled . The basic information includes age, sex, height,body mass, history of smoking, blood pressure, heart rate, history of coronary heart disease, ischemic stoke, chronic kidney diseases and diabetes,etc. The fasting blood sugar(FBS) ,blood lipid( total cholesterel,triglyceride, low-density lipreprotein, high-deusity liproprotein), serum creatinine, serum uric acid, serum alanine aminotransferase were measured. The elders were divided into two groups according to the PP( PP 160岁患有动脉粥样硬化危险因素的患者2358人,记录入选者的基本情况:年龄、性别、身高、体重、吸烟史,血压、心率、冠心病、缺血性脑卒中、慢性肾脏病、糖尿病等病史.测定空腹血糖、总胆固醇、甘油三酯、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、血肌酐、尿酸、丙氨酸氨基转移酶.根据脉压将入选者分为脉压<60 mm Hg组和≥60 mm Hg组.分析2组脉压与年龄、体重指数、收缩压、舒张压、心率、空腹血糖、血脂、血肌酐、尿酸、丙氨酸氨基转移酶、肌酐清除率、冠心痛、缺血性脑卒中、慢性肾脏病、糖尿病等关系.结果 脉压≥60 mm Hg组与脉压<60 mm Hg组比较,血糖[(6.3±2.6)mmol/L与(5.6±1.7)mmol/L]、总胆固醇[(4.8±1.2)mmol/L与(4.3±1.3)mmol/L]、甘油三酯[(1.9±1.1)mmol/L与(1.5±1.2)mmol/L]、低密度脂蛋白胆固醇[(2.9±1.2)mmoL/L与(2.5±1.1)mmol/L]、尿酸[(291.4±133.6)μmol/L与(246.8±131.2)μmoL/L]均明显升高(P均<0.01).脉压≥60mm Hg组与脉压<60 mm Hg组比较,冠心病(17.8%与10.8%)、缺血性脑卒中(31.7%与26.0%)、慢性肾脏病(16.9%与12.4%)、糖尿病(23.8%与17

  17. 喷吹压力与喷吹距离对长滤袋清灰效果的研究%Effect of the pulse pressure and the jet distance on the cleaning performance of the long pulse-jet filter bag

    Institute of Scientific and Technical Information of China (English)

    吕娟; 颜翠平; 袁彩云; 付瑜; 李雪; 陈海焱

    2016-01-01

    The present paper is aimed at introducing its investigation results on the effects of the pulse pressure and the jet distance on the cleaning performance of the long pulse-jet filter bag in order to promote the optimistic design for a semi-industrial pulse-jet filter bag.For the aforementioned purpose,we have adopted the peak pressure and the speed to arrive at the peak pressure as the idealistic indexes for the evaluation of the pulse cleaning effects.In doing so,we have adopted 8 high precision piezoelectric pressure transducers (according to Model QSY8135)to examine and measure the peak pressure and the time for reaching the peak pressure to be shown on the internal surface of the filter bag (160 mm ×6 000 mm),which is made of the polyester needle-felt.The evaluation results have shown that it would be possible to realize the optimum design in a semi-industrial pulsejet filter bag when the pulse pressure is set on 0.1-0.3 MPa in a distance of 200 mm.Our investigation has also proven that the peak pressure tends to increase from the top opening and then reach the maximum value at the location of 1 m in the length of the filter bag.And then,the peak pressure would like to drop gradually,and later to rise again at the bottom of the filter bag on its surface.Thus,the peak pressure distribution tends to be uneven along its surface and it would take 0 to 4 000 mm to reach its peak pressure in its length and decrease from 4 000 mm to 6 000mm,with the average peak pressure values along its length being 2.076 8 kPa,3.292 1 kPa and 4.325 2 kPa,on the condition that the pulse pressure keeps at 0.1-0.3 MPa and the distance stays at 200 mm,respectively.What is more,with the average peak pressures obtained under the optimum parameter design condition,the pulse cleaning results prove to be suitable for practical applications.Thus,it can be concluded that the investigation and experiments we have done can not only be expected to lay a theoretical basis for the study of the

  18. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Joseph Rovani; Mark Sanderson

    2008-02-29

    outputs of mercury generators are compared to one another using a nesting procedure which allows direct comparison of one generator with another and eliminates analyzer variability effects. The qualification portion of the EPA interim traceability protocol requires the vendors to define generator performance as affected by variables such as pressure, temperature, line voltage, and shipping. WRI is focusing efforts to determine actual generator performance related to the variables defined in the qualification portion of the interim protocol. The protocol will then be further revised by EPA based on what can actually be achieved with the generators. Another focus of the study is to evaluate approaches for field verification of generator performance. Upcoming work includes evaluation of oxidized mercury calibration generators, for which a separate protocol will be prepared by EPA. In addition, the variability of the spectrometers/analyzers under various environmental conditions needs to be defined and understood better. A main objective of the current work is to provide data on the performance and capabilities of elemental mercury generator/calibration systems for the development of realistic NIST traceability protocols for mercury vapor standards for continuous emission CEM calibration. This work is providing a direct contribution to the enablement of continuous emissions monitoring at coal-fired power plants in conformance with the CAMR. EPA Specification 12 states that mercury CEMs must be calibrated with NIST-traceable standards (Federal Register 2005). The initial draft of an elemental mercury generator traceability protocol was circulated by EPA in May 2007 for comment, and an interim protocol was issued in August 2007 (EPA 2007). Initially it was assumed that the calibration and implementation of mercury CEMs would be relatively simple, and implementation would follow the implementation of the Clean Air Interstate Rule (CAIR) SO{sub 2} and NO{sub x} monitoring, and

  19. AVR单片机下脉搏传导时间与收缩压的关系%Research on pulse transit time and systolic blood pressure with AVR microcontroller

    Institute of Scientific and Technical Information of China (English)

    王帅; 刘力夫; 沙宪政

    2015-01-01

    Objective The relationship between pulse transit time ( PTT) and invasive systolic blood pressure is analyzed with the data in MIMIC Database� A signal acquisition system which can obtain real time ECG and pulse signal is developed with AVR microcontroller and PC to analyze the relationship between the noninvasive systolic pressure and PTT� Methods Signals of 5 persons in the MIMIC Database are handled with Matlab software� The correlation coefficient between PTT and invasive systolic pressure is obtained� Six recruited normotensive male subjects ( aged 27 to 31 years) are tested with the system� Data of ECG signals and PPG signals are sent to PC via blue tooth� Then a two⁃month repeatability test is conducted on 4 subjects to test if there is a big change in the same subject� Results PPT has good linear relation with both invasive and noninvasive systolic pressure� Better linear relation can be achieved when the trough of the pulse wave is used as the characteristic point� Conclusions AVR data acquisition system is compact, portable, and can be applied in home care.%目的:利用MIMIC Datebase( mimicdb)数据分析有创收缩压和脉搏传导时间( pulse transit time, PTT)的关系。制作AVR信号采集系统,并在PC下采集心电和脉搏的实时信号,分析无创收缩压和PTT的关系。方法利用Matlab软件分析MIMIC数据库内5个个体的数据,得出PTT和有创收缩压的相关系数。利用AVR单片机采集用6名正常血压的男性(年龄27~31周岁)的心电和脉搏信号,用蓝牙发送至计算机。通过两个月对比试验,比较PTT和收缩压之间的关系是否发生很大的变化。结果PTT同有创和无创收缩压都有较好的线性相关性,波谷作为PTT特征点和收缩压有更好的线性关系。结论 AVR数据采集系统小巧、便携,可应用于家用监护。

  20. Effects of Dynamic Pulse Pressure on Renal Damage in Aged Patients with Primary Hypertension%老年高血压患者脉压差对肾脏损害的影响研究

    Institute of Scientific and Technical Information of China (English)

    吴红红; 段磊; 山努佳; 何英

    2011-01-01

    目的 探讨动态脉压对老年高血压患者肾脏损害的影响.方法 选择原发性高血压患者165例,按24 h平均脉压(MPP)分为两组:24 h MPP≥60 mm Hg为A组,24 h MPP<60 mm Hg为B组;另选健康体检正常者为对照组,均进行血清肌酐、动态血压测定.结果 3组24 h平均收缩压(MSBP)、24 h平均舒张压(MDBP)、24 h MPP、血清肌酐、尿清蛋白排泄率(UAER)、肾小球滤过率(GRF)水平比较,差异均有统计学意义(P<0.05).其中A组和B组患者24 h MSBP、24 h MPP较C组明显升高(P<0.05);与B组比较,A组患者上述指标明显升高(P<0.05);A组血清肌酐明显高于B组和C组,24 h MDBP及GRF低于B组和C组(P<0.05).结论 动态脉压增大与老年高血压患者靶器官结构和功能的损害相关;动态脉压越大,靶器官损害越严重.%Objective To investigate the effects of dynamic pulse pressure on renal damage in aged patients with primary hypertension.Methods A total of 165 aged patients with primary hypertension were divided into two groups ( group A: 24 h MPP ≥60 mm Hg; group B∶ 24 h MPP < 60 mm Hg ) according to the 24 hour mean pulse pressure ( 24 h MPP ).Healthy subjects were enrolled as the control group ( group C ).Serum creatinine levels and data from ambulatory blood pressure monitoring were collected from all subjects.Results Comparesion of 24 h mean systolic pressure ( MSBP), 24 h mean diastolic blood pressure ( MDBP ), 24 h MPP, serum creatinine, urinary albumin excretion rate ( UAER ), glomerular filtration rate ( GRF ) among the three groups showed significant differences ( P <0.05 ).The 24 h MSBP and 24 h MPP levels were found to be significantly higher in group A and group B compared with group C ( P < 0.01 ), with group A higher than group B ( P < 0.01 ).Group A also had elevated serum creatinine levels and lower levels of MDBP when compared to group B and group C ( P <0.05 ).Conclusion The elevated dynamic pulse pressure levels are correlated

  1. The Relationship between the Pulse Pressure of Spontaneously Hypertensive Rats and Ventricular Fibrillation Threshold%自发高血压大鼠脉压与心室颤动的关系

    Institute of Scientific and Technical Information of China (English)

    黄宇理; 徐玮; 宣玲; 李妙男; 孙强; 史晓俊

    2013-01-01

    Objective:To observe the relationship between the pulse pressure of spontaneously hypertensive rats and their ventricular fibril ation threshold. Method:Twenty-four ten-weeks-old spontaneously hypertensive male rats were randomly divided into 3 groups:eighteen-weeks-old group (n=8), which were fed to eighteen-weeks-old to do the experiment;Twenty-weeks-old group (n=8), which were fed to twenty-weeks-old to do the experiment;and the 10-weeks-old group (n=8), and eight 10-weeks-old Wistar male rats as control group. Measure the pulse pressure, the ventricular fibril ation threshold and the ventricular effective refractory periods of the rats of every group. Result: With the growth of age, the pulse pressure of the spontaneously hypertensive rats increased (P<0.05), and the ventricular fibril ation threshold decreased gradual y (P<0.05). The ventricular fibril ation threshold and the pulse pressure were of a negative correlation. Conclusion:With the growth of age, the higher the pulse pressure of the spontaneously hypertensive rats, the lower the ventricular fibril ation threshold, and these rats were tender to have malignant ventricular arrhythmia, which lead to sudden death.%目的:观察自发高血压大鼠脉压与心室颤动阈值的关系。方法:10周龄雄性自发高血压大鼠共24只,随机分成3组:喂养至18周龄行实验,即18周龄组( n=8);喂养至24周龄行实验,即24周龄组( n=8);10周龄组( n=8);另取8只雄性10周龄Wistar大鼠作为对照组,测量各组大鼠的脉压、心室颤动阈值、心室有效不应期。结果:在自发高血压大鼠中,随着周龄的增长,脉压增大(P<0.05),心室颤动阈值逐渐降低(P<0.05)。心室颤动阈值与脉压呈负相关(r=-0.85,P<0.05)。结论:在自发高血压大鼠中,随着周龄的增长,脉压愈大,心室颤动阈值愈低,易发生恶性室性心律失常,导致心源性猝死。

  2. Trinocular Calibration Method Based on Binocular Calibration

    Directory of Open Access Journals (Sweden)

    CAO Dan-Dan

    2012-10-01

    Full Text Available In order to solve the self-occlusion problem in plane-based multi-camera calibration system and expand the measurement range, a tri-camera vision system based on binocular calibration is proposed. The three cameras are grouped into two pairs, while the public camera is taken as the reference to build the global coordinate. By calibration of the measured absolute distance and the true absolute distance, global calibration is realized. The MRE (mean relative error of the global calibration of the two camera pairs in the experiments can be as low as 0.277% and 0.328% respectively. Experiment results show that this method is feasible, simple and effective, and has high precision.

  3. Boeing infrared sensor (BIRS) calibration facility

    Science.gov (United States)

    Hazen, John D.; Scorsone, L. V.

    1990-01-01

    The Boeing Infrared Sensor (BIRS) Calibration Facility represents a major capital investment in optical and infrared technology. The facility was designed and built for the calibration and testing of the new generation large aperture long wave infrared (LWIR) sensors, seekers, and related technologies. Capability exists to perform both radiometric and goniometric calibrations of large infrared sensors under simulated environmental operating conditions. The system is presently configured for endoatmospheric calibrations with a uniform background field which can be set to simulate the expected mission background levels. During calibration, the sensor under test is also exposed to expected mission temperatures and pressures within the test chamber. Capability exists to convert the facility for exoatmospheric testing. The configuration of the system is described along with hardware elements and changes made to date are addressed.

  4. Doppler imaging of myocardium tissue from aged hypertensive patients with increased differential pulse pressure%老年脉压差增大高血压患者心肌多普勒成像改变

    Institute of Scientific and Technical Information of China (English)

    王新明; 孙红

    2012-01-01

    Objective To assess the effect of increased differential pulse pressure on myocardium function in aged patients by tissue Doppler imaging(TDI). Medthods One hundred and one aged patients were divided into normal pressure group with their differential pulse pressure ≤40 mm Hg(n = 45) and hypertension group with their differential pulse >40 mm Hg(n = 56). The inner diameter and interventricular septal thickness of ascending aorta,thickness of lefet ventricle posterior wall,inner diameter of left ventricle at late diastolic phase,maximum blood flow speed through mitral vlve at early diastolic phase were measured to detect the peak blood flow speed at diastolic phase,early diastolic phase and late diastolic phase. Results The peak blood flow speed at diastolic phase,early diastolic phase and late diastolic phase was higher in hypertension group than in normal pressure group. Conclusion TDI is a reliable new procedure for the diagnosis of abnormal systolic and diastolic function of myocardium due to increased differential pulse pressure in aged patients with hypertension. The mitral valve ring in left ventricular septum is sensitive to TDI in measuring systolic pressure.%目的 应用组织多普勒超声成像评价老年脉压差增大对心肌收缩和舒张功能的影响.方法 应用常规超声心动图及组织多普勒等方法检测左心室射血分数>50%的老年男性高血压患者共101例,其中血压正常、脉压差≤40 mm Hg(1 mm Hg=0.133 kPa)45例(正常组),高血压、且脉压差>40 mm Hg 56例(异常组),测量升主动脉内径、室间隔厚度、左心室后壁厚度、左心室舒张末内径、左心室舒张早期二尖瓣血流最大速度和左心室舒张晚期二尖瓣血流最大速度(A)值,获取舒张期室间隔基底部组织多普勒收缩期峰值速度(s)、舒张早期峰值速度、舒张晚期峰值速度(a).结果 异常组A值、a峰、s峰明显高于正常组,差异有统计学意义(P<0.05,P<0.01).

  5. A compact array calibrator to study the feasibility of acoustic neutrino detection

    Directory of Open Access Journals (Sweden)

    Ardid M.

    2016-01-01

    Full Text Available Underwater acoustic detection of ultra-high-energy neutrinos was proposed already in 1950s: when a neutrino interacts with a nucleus in water, the resulting particle cascade produces a pressure pulse that has a bipolar temporal structure and propagates within a flat disk-like volume. A telescope that consists of thousands of acoustic sensors deployed in the deep sea can monitor hundreds of cubic kilometres of water looking for these signals and discriminating them from acoustic noise. To study the feasibility of the technique it is critical to have a calibrator able to mimic the neutrino “signature” that can be operated from a vessel. Due to the axial-symmetry of the signal, their very directive short bipolar shape and the constraints of operating at sea, the development of such a calibrator is very challenging. Once the possibility of using the acoustic parametric technique for this aim was validated with the first compact array calibrator prototype, in this paper we describe the new design for such a calibrator composed of an array of piezo ceramic tube transducers emitting in axial direction.

  6. A compact array calibrator to study the feasibility of acoustic neutrino detection

    Science.gov (United States)

    Ardid, M.; Camarena, F.; Felis, I.; Herrero, A.; Llorens, C. D.; Martínez-Mora, J.; Saldaña, M.

    2016-04-01

    Underwater acoustic detection of ultra-high-energy neutrinos was proposed already in 1950s: when a neutrino interacts with a nucleus in water, the resulting particle cascade produces a pressure pulse that has a bipolar temporal structure and propagates within a flat disk-like volume. A telescope that consists of thousands of acoustic sensors deployed in the deep sea can monitor hundreds of cubic kilometres of water looking for these signals and discriminating them from acoustic noise. To study the feasibility of the technique it is critical to have a calibrator able to mimic the neutrino "signature" that can be operated from a vessel. Due to the axial-symmetry of the signal, their very directive short bipolar shape and the constraints of operating at sea, the development of such a calibrator is very challenging. Once the possibility of using the acoustic parametric technique for this aim was validated with the first compact array calibrator prototype, in this paper we describe the new design for such a calibrator composed of an array of piezo ceramic tube transducers emitting in axial direction.

  7. 超声波-脉动压联用快速腌制咸鸭蛋的工艺参数优化%Parameter optimization for quickly salted egg by using ultrasonic-pulsed pressure technology

    Institute of Scientific and Technical Information of China (English)

    王石泉; 王树才; 张益鹏; 张融

    2013-01-01

    咸鸭蛋的腌制周期很长,一般夏季20~30 d、春秋季40~50 d。为了提高咸蛋的腌制效率,采用超声波-脉动压联用技术,选取高压幅值、高压脉动比和超声波作用时间为影响因素,通过单因素和正交试验,测定咸蛋腌制过程中蛋清含盐量和蛋黄含盐量的变化,对超声波-脉动压联用技术在咸蛋快速腌制中的工艺参数进行优化。结果表明:采用质量分数为24%食盐溶液,在恒温30℃条件下腌制3 d,综合咸蛋品质和食盐传质速率得出最佳工艺参数:高压幅值为140 kPa,高压脉动比为4 min:16 min,超声波作用时机应在第1天,超声波脉动比为2 min:10 min,超声波作用时长为132 min,可以腌制出效果较好的咸蛋,蛋白食盐含量为4.61%,蛋黄食盐含量为2.12%,而含盐量差值只有2.49%。感官评定此组咸蛋具有蛋白细嫩、咸味适中;蛋黄松沙、含油、咸味可口的特点。同时生产周期比传统腌制方法缩短了90%,可为咸蛋的工业化生产提供技术参考。%The pickled cycle of salted duck eggs is a very long time. It usually takes twenty days to thirty days (in spring and summer) and forty days to fifty days (in autumn and winter) to make the salted duck eggs. Therefore, reducing the time of making salted eggs became the issue which domestic scholars were concerned about. The quality of salted duck eggs has the characteristics of moderate salinity, deliciousness, pure protein, delicate, crispy yolk, and the flow of yolk oil. Ultrasonic technology and pulsed pressure technology was applied to accelerate the process of salting duck eggs. We fabricated a rapid salted experimental apparatus of a duck's egg, which mainly contained the pressure vessel, the air compressor, the circulating system, heating devices, and control systems. The effects of the pulse pressure amplitude, the high pressure holding time/atmospheric pressure holding time ratio, and

  8. Experimental characterization and modeling for the growth rate of oxide coatings from liquid solutions of metalorganic precursors by ultrasonic pulsed injection in a cold-wall low-pressure reactor

    Science.gov (United States)

    Krumdieck, Susan Pran

    Several years ago, a method for depositing ceramic coatings called the Pulsed-MOCVD system was developed by the Raj group at Cornell University in association with Dr. Harvey Berger and Sono-Tek Corporation. The process was used to produce epitaxial thin films of TiO2 on sapphire substrates under conditions of low pressure, relatively high temperature, and very low growth rate. The system came to CU-Boulder when Professor Raj moved here in 1997. It is quite a simple technique and has several advantages over typical CVD systems. The purpose of this dissertation is two-fold; (1) understand the chemical processes, thermodynamics, and kinetics of the Pulsed-MOCVD technique, and (2) determine the possible applications by studying the film structure and morphology over the entire range of deposition conditions. Polycrystalline coatings of ceramic materials were deposited on nickel in the low-pressure, cold-wall reactor from metalorganic precursors, titanium isopropoxide, and a mixture of zirconium isopropoxide and yttria isopropoxide. The process utilized pulsed liquid injection of a dilute precursor solution with atomization by ultrasonic nozzle. Thin films (less than 1mum) with fine-grained microstructure and thick coatings (up to 1mum) with columnar-microstructure were deposited on heated metal substrates by thermal decomposition of a single liquid precursor. The influence of each of the primary deposition parameters, substrate temperature, total flow rate, and precursor concentration on growth rate, conversion efficiency and morphology were investigated. The operating conditions were determined for kinetic, mass transfer, and evaporation process control regimes. Kinetic controlled deposition was found to produce equiaxed morphology while mass transfer controlled deposition produced columnar morphology. A kinetic model of the deposition process was developed and compared to data for deposition of TiO2 from Ti(OC3H7) 4 precursor. The results demonstrate that growth

  9. Measurement of OH (X2Σ) in immediate vicinity of dielectric surface under pulsed dielectric barrier discharge at atmospheric pressure using two geometries of laser-induced fluorescence

    Science.gov (United States)

    Teramoto, Yoshiyuki; Kim, Hyun-Ha; Ogata, Atsushi; Negishi, Nobuaki

    2014-04-01

    The behavior of the ground state OH radical was studied in humid air using pulsed surface dielectric barrier discharge. The validity of OH measurement in immediate vicinity of the dielectric surface was discussed using two geometries of laser-induced fluorescence (LIF) measurement, and surface distribution and temporal profiles of OH were examined. A comparison of parallel- and perpendicular-LIF techniques for OH measurement revealed that OH was mostly produced in a region several tens of μm above the dielectric surface. The surface distribution profile of OH agreed well with that of N2(C), and in both cases, the total production generated by a discharge pulse was proportional to the discharge energy. The OH local density in surface streamer channels was estimated to be 1.3 × 1015 cm-3 according to the decay rate of OH, which was similar to that in corona discharge. Additionally, the local density of OH remained constant regardless of discharge energies. These results indicate that the yield of OH increased with the discharge energy owing to expansion of the surface streamer region, increase in streamer radius or thickness or the number of branches, whereas the local density of OH in the streamer channel remained constant regardless of discharge energy.

  10. Investigation on Propagation of Back-Pressure in Air-Breathing Pulse Detonation Engine%吸气式脉冲爆震发动机反压传播规律研究

    Institute of Scientific and Technical Information of China (English)

    彭畅新; 王治武; 郑龙席; 卢杰; 陈星谷

    2013-01-01

    With gasoline as fuel and air as oxidizer, experiments were performed to investigate the propagation of back-pressure in an air-breathing pulse detonation engine (PDE) with inner diameter 60mm, The back-pressure was measured at different operation frequencies ranging from 10 Hz to 30 Hz. The experimental results show that the back-pressure approximately increases linearly with increasing frequency. The ratio that the time of pressure fluctuation to a cycle time increases with increasing frequency. The pressure oscillation has a maximum value with operation frequency of 20Hz. The numerical model was developed and the characteristic of formation and propagation of the back-pressure was numerically investigated. The simulation results confirm that the back-pressure is induced by the retonation wave. The experimental and numerical results agree well, indicating that the method of simulation can reasonably reflect the propagation process of back-pressure.%以汽油为燃料,空气为氧化剂,在内径为60mm的吸气式脉冲爆震发动机上进行了反压传播规律实验研究.测量了10 ~30Hz频率范围内进气道内的反传压力.实验结果表明,进气道内的反压峰值随着工作频率的增加而增加,两者基本呈线性关系.随着工作频率的增加,压力波动的时间占每个工作循环时间的比例增加.压力脉动比在20Hz时达到最大.建立了数值模型,采用小能量点火及温度梯度自适应方法,计算得到了反压的形成及传播特性.计算结果印证了反压是由于回传爆震引起的.将计算结果与实验结果进行了比较,结果表明两者符合地较好.

  11. The calibration of PIXIE

    Science.gov (United States)

    Fixsen, D. J.; Chuss, D. T.; Kogut, Alan; Mirel, Paul; Wollack, E. J.

    2016-07-01

    The FIRAS instrument demonstrated the use of an external calibrator to compare the sky to an instrumented blackbody. The PIXIE calibrator is improved from -35 dB to -65 dB. Another significant improvement is the ability to insert the calibrator into either input of the FTS. This allows detection and correction of additional errors, reduces the effective calibration noise by a factor of 2, eliminates an entire class of systematics and allows continuous observations. This paper presents the design and use of the PIXIE calibrator.

  12. Observation on the efifcacy of low frequency pulse rehabilitation therapy after negative pressure suction%负压吸宫术后低频脉冲康复理疗疗效观察

    Institute of Scientific and Technical Information of China (English)

    罗国芳; 向梅枝; 徐玉清

    2015-01-01

    Objective To investigate the application value of low frequency pulse therapy in the rehabilitation of patients with negative pressure suction. Methods 400 cases of patients with negative pressure suction palace were randomly divided into control group and experimental group, each group had 200 cases. the 2 groups were treated with conventional therapy and nursing, and the experimental group was treated with low frequency pulse therapy. The vaginal bleeding, vaginal bleeding volume, postoperative abdominal pain, pelvic discomfort, vaginal discharge and transfer time were compared between the 2 groups. Results the duration of pelvic discomfort in the experimental group and vaginal bleeding duration were shorter than the control group, the vaginal bleeding volume was significantly less than that of the control group, the difference was statistically significant (P<0.05). Conclusion the low frequency pulse therapy apparatus is safe and effective in the treatment of uterine recovery after negative pressure suction.%目的:探讨低频脉冲治疗仪在负压吸宫术后康复中的应用价值。方法将负压吸宫术患者400例随机分为对照组和实验组各200例。2组术后均采用传统治疗、护理,实验组术后即用低频脉冲治疗仪治疗。比较2组术后阴道出血时间、阴道出血量、术后腹痛、盆腔不适、阴道排液及转经时间。结果实验组盆腔不适持续时间及阴道出血持续时间均短于对照组,阴道流血量明显少于对照组,差异均有统计学意义(P<0.05)。结论低频脉冲治疗仪在促进负压吸宫术后子宫康复中安全有效,值得推广应用。

  13. Relationship Between Ambulatory Blood Pressure Parameters and Pulse Wave Velocity in Prehypertensive Patients%血压正常高值者动脉僵硬度与动态血压参数的关系

    Institute of Scientific and Technical Information of China (English)

    胡小亮; 路方红; 刘振东; 赵颖馨; 孙尚文; 王舒健; 潘慧; 李俊

    2012-01-01

    Aim To investigate the relationship between ambulatory blood pressure parameters and arterial stiffness in prehypertensive patients. Methods According to their blood pressure level, 204 individuals were divided into three groups: namely normotensive controls ( n = 63 ) , prehypertensive participants ( n = 74 ) and hypertensive patients ( n = 67) . The 24 h ambulatory blood pressure monitoring was used to record 24 h systolic blood pressure (24h SBP) , 24 h diastolic blood pressure (24h DBP) , daytime systolic blood pressure (dSBP) , daytime diastolic blood pressure (dDBP) , nighttime systolic blood pressure (nSBP) , nighttime diastolic blood pressure (nDBP) , 24 h pulse pressure (24h PP) , daytime pulse pressure ( dPP) and nighttime pulse pressure ( nPP) . Carotid-radial pulse wave velocity ( crPWV) was obtained by Complior device. Results 24h SBP, 24h DBP, dSBP, dDBP, nSBP, 24h PP, dPP and nPP were higher in prehypertensive than those in normotensives, but lower in hypertensives ( P < 0. 05 or P < 0. 01) . The crPWV in prehy-pertensives was 9. 67 ± 1. 12 m/s, which was higher than that in normotensives (8. 27 ±0. 99 m/s) , but was lower in hypertensives (10. 55 ± 1. 71 m/s) . Multiple linear regression analysis showed that 24h SBP, 24h PP and nSBP were risk factors for crPWV ( B = 0. 385 , 0351 and 0. 247; all P < 0. 05 ) . Conclusion Arterial stiffness had been increased inprehypertensives. 24h SBP, 24h PP and nSBP are the important influencing factors of arterial stiffness.%目的 探讨血压正常高值者动脉僵硬度与动态血压参数的关系.方法 选择理想血压者63例,血压正常高值者74例,高血压者67例.监测所有入选者24h动态血压,应用脉搏波传导速度测定仪测定颈动脉-桡动脉脉搏波传导速度.结果 血压正常高值组24 h收缩压、24 h舒张压、白昼收缩压、白昼舒张压、夜间收缩压、24 h脉压、白昼脉压及夜间脉压均高于理想血压组,低于高血压组(P<0.05或P<0

  14. Velocidade da onda de pulso, pressão arterial e adipocitocinas em adultos jovens: estudo do Rio de Janeiro Pulse wave velocity, blood pressure and adipocytokines in young adults: the Rio de Janeiro study

    Directory of Open Access Journals (Sweden)

    Oswaldo Luiz Pizzi

    2012-01-01

    identificação do acometimento vascular nessa faixa etária.BACKGROUND: Data on noninvasive vascular assessment and their association with cardiovascular risk variables are scarce in young individuals. OBJECTIVE: To evaluate the association between pulse wave velocity and blood pressure, anthropometric and metabolic variables, including adipocytokines, in young adults. METHODS: A total of 96 individuals aged 26 to 35 years (mean 30.09 ± 1.92; 51 males were assessed in the Rio de Janeiro study. Pulse wave velocity (Complior method, blood pressure, body mass index, glucose, lipid profile, leptin, insulin, adiponectin and insulin resistance index (HOMA-IR were analyzed. Subjects were stratified into three groups according to the PWV tertile for each gender. RESULTS: The group with the highest pulse wave velocity (PWV tertile showed higher mean systolic and diastolic blood pressure, mean blood pressure, body mass index, insulin, and HOMA-IR, as well as lower mean adiponectin; higher prevalence of diabetes mellitus/glucose intolerance and hyperinsulinemia. There was a significant positive correlation of PWV with systolic blood pressure, diastolic blood pressure, pulse pressure and mean blood pressure, body mass index, and LDL-cholesterol, and a negative correlation with HDL-cholesterol and adiponectin. In the multiple regression model, after adjustment of HDL-cholesterol, LDL-cholesterol and adiponectin for gender, age, body mass index and mean blood pressure, only the male gender and mean blood pressure remained significantly correlated with PWV. CONCLUSION: PWV in young adults showed a significant association with cardiovascular risk variables, especially in the male gender, and mean blood pressure as important determinant variables. The findings suggest that PWV measurement can be useful for the identification of vascular impairment in this age group.

  15. Velocidade da onda de pulso, pressão arterial e adipocitocinas em adultos jovens: estudo do Rio de Janeiro Pulse wave velocity, blood pressure and adipocytokines in young adults: the Rio de Janeiro study

    Directory of Open Access Journals (Sweden)

    Oswaldo Luiz Pizzi

    2013-01-01

    identificação do acometimento vascular nessa faixa etária.BACKGROUND: Data on noninvasive vascular assessment and their association with cardiovascular risk variables are scarce in young individuals. OBJECTIVE: To evaluate the association between pulse wave velocity and blood pressure, anthropometric and metabolic variables, including adipocytokines, in young adults. METHODS: A total of 96 individuals aged 26 to 35 years (mean 30.09 ± 1.92; 51 males were assessed in the Rio de Janeiro study. Pulse wave velocity (Complior method, blood pressure, body mass index, glucose, lipid profile, leptin, insulin, adiponectin and insulin resistance index (HOMA-IR were analyzed. Subjects were stratified into three groups according to the PWV tertile for each gender. RESULTS: The group with the highest pulse wave velocity (PWV tertile showed higher mean systolic and diastolic blood pressure, mean blood pressure, body mass index, insulin, and HOMA-IR, as well as lower mean adiponectin; higher prevalence of diabetes mellitus/glucose intolerance and hyperinsulinemia. There was a significant positive correlation of PWV with systolic blood pressure, diastolic blood pressure, pulse pressure and mean blood pressure, body mass index, and LDL-cholesterol, and a negative correlation with HDL-cholesterol and adiponectin. In the multiple regression model, after adjustment of HDL-cholesterol, LDL-cholesterol and adiponectin for gender, age, body mass index and mean blood pressure, only the male gender and mean blood pressure remained significantly correlated with PWV. CONCLUSION: PWV in young adults showed a significant association with cardiovascular risk variables, especially in the male gender, and mean blood pressure as important determinant variables. The findings suggest that PWV measurement can be useful for the identification of vascular impairment in this age group.

  16. Effect of Pulse Nanosecond Volume Discharge in Air at Atmospheric Pressure on Electrical Properties of Mis Structures Based on p-HgCdTe Grown by Molecular Beam Epitaxy

    Science.gov (United States)

    Voitsekhovskii, A. V.; Nesmelov, S. N.; Dzyadukh, S. M.; Grigor'ev, D. V.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    The effect of the pulse nanosecond volume discharge in air at atmospheric pressure on the admittance of MIS structures based on MBE graded-gap p-Hg0.78Cd0.22Te is studied in a wide range of frequencies and temperatures. It is shown that the impact of the discharge leads to significant changes in electrical characteristics of MIS structures (the density of positive fixed charge increases), to the changes in the nature of the hysteresis of capacitance-voltage characteristics, and to an increase in the density of surface states. A possible reason for the changes in the characteristics of MIS structures after exposure to the discharge is substantial restructuring of the defect-impurity system of the semiconductor near the interface.

  17. Influence of the reactive atmosphere on the formation of nanoparticles in the plasma plume induced by nanosecond pulsed laser irradiation of metallic targets at atmospheric pressure and high repetition rate

    Science.gov (United States)

    Girault, M.; Le Garrec, J.-L.; Mitchell, J. B. A.; Jouvard, J.-M.; Carvou, E.; Menneveux, J.; Yu, J.; Ouf, F.-X.; Carles, S.; Potin, V.; Pillon, G.; Bourgeois, S.; Perez, J.; Marco de Lucas, M. C.; Lavisse, L.

    2016-06-01

    The influence of a reactive atmosphere on the formation of nanoparticles (NPs) in the plasma plume generated by nanosecond pulsed laser irradiation of metal targets (Ti, Al, Ag) was probed in situ using Small Angle X-ray Scattering (SAXS). Air and different O2-N2 gas mixtures were used as reactive gas within atmospheric pressure. SAXS results showed the formation of NPs in the plasma-plume with a mean radius varying in the 2-5 nm range. A decrease of the NPs size with increasing the O2 percentage in the O2-N2 gas mixture was also showed. Ex situ observations by transmission electron microscopy and structural characterizations by X-ray diffraction and Raman spectroscopy were also performed for powders collected in experiments done using air as ambient gas. The stability of the different metal oxides is discussed as being a key parameter influencing the formation of NPs in the plasma-plume.

  18. 高压脉冲智能润滑技术在转炉电除尘系统中的应用%Application of High-pressure Pulse Intelligence Lubrication Technology in the Converter Electrical Precipitator System

    Institute of Scientific and Technical Information of China (English)

    侯风岭; 吴强

    2011-01-01

    针对转炉电除尘系统中集中干油润滑系统和智能润滑系统存在的管路易堵塞、润滑不均以及维修维护困难等问题,设计一套高压脉冲智能润滑系统.该系统采用多点电磁脉冲分配器,确保了每个润滑点油路的畅通和良好的润滑;采用先进的车削密封,分配器和轴承密封性能好,使用寿命长,降低了设备维护成本.%Aimed at the problems existed in the centralized glycerine lubrication system and intelligent lubrication system such as pipeline blocked easily,lubrication inequality and maintenance difficulties in the converter electrical precipitator system,a set of high-pressure pulsed intelligent lubrication system was designed.This system uses multi-point electromagnetic pulse divider, which ensures each lubricating points oil unblocked and good lubrication;adopting advanced turning seal, the distributors and bearing has good seal performance, long use life and low maintenance cost.

  19. Polarimetric Calibration of a Bistatic SAR detector

    OpenAIRE

    Yam Ontiveros, Luis Eduardo

    2010-01-01

    The polarimetric radars o er the advantage of knowing about properties of target's surface by acquiring information of how the incident electromagnetic energy is scattered respect to orthogonal polarization vectors. Bistatic sensors of opportunity, such as SABRINA, can be adapted to perform polarimetric measurements if they found an illuminator which transmits pulses with orthogonal polarizations. In such scenario, calibration is required to scale properly the measurements in m...

  20. Timepix detector energy calibration using synchrotron light

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, Kazuyoshi; Vicente, Mateus, E-mail: mateus_vicente@live.com [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Benoit, Mathieu [CERN (France)

    2014-07-01

    The Timepix is a hybrid pixelated detector. It is able to measure the energy of an incident particle on its sensor and provide the particle position within its matrix of 256x256 pixels 55 μm{sup 2} simultaneously. It has direct applications in high energy physics and medical physics. The energy collected by the sensor is translated into an analog electrical pulse and then converted into a digital signal for the readout. To relate in a precise way the digital signal with the actual values of energy, an energy calibration is required. In this work a method of calibration and analysis for the calibration of the detector will be presented. (author)

  1. A new technique for assessing arterial pressure wave forms and central pressure with tissue Doppler

    Science.gov (United States)

    Haluska, Brian A; Jeffriess, Leanne; Mottram, Phillip M; Carlier, Stephane G; Marwick, Thomas H

    2007-01-01

    Background Non-invasive assessment of arterial pressure wave forms using applanation tonometry of the radial or carotid arteries can be technically challenging and has not found wide clinical application. 2D imaging of the common carotid arteries is routinely used and we sought to determine whether arterial waveform measurements could be derived from tissue Doppler imaging (TDI) of the carotid artery. Methods We studied 91 subjects (52 men, age 52 ± 14 years) with and without cardiovascular disease. Tonometry was performed on the carotid artery simultaneously with pulsed wave Doppler of the LVOT and acquired digitally. Longitudinal 2D images of the common carotid artery with and without TDI were also acquired digitally and both TDI and tonometry were calibrated using mean and diastolic cuff pressure and analysed off line. Results Correlation between central pressure by TDI and tonometry was excellent for maximum pressure (r = 0.97, p < 0.0001). The mean differences between central pressures derived by TDI and tonometry were minimal (systolic 5.36 ± 5.5 mmHg; diastolic 1.2 ± 1.2 mmHg). Conclusion Imaging of the common carotid artery motion with tissue Doppler may permit acquisition of a waveform analogous to that from tonometry. This method may simplify estimation of central arterial pressure and calculation of total arterial compliance. PMID:17266772

  2. Distributed Radio Interferometric Calibration

    CERN Document Server

    Yatawatta, Sarod

    2015-01-01

    Increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. In this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. We exploit the data parallelism across frequency that is inherent in radio astronomical observations that are recorded as multiple channels at different frequencies. Moreover, we also exploit the smoothness of the variation of calibration parameters across frequency. Data parallelism enables us to distribute the computing load across a network of compute agents. Smoothness in frequency enables us reformulate calibration as a consensus optimization problem. With this formulation, we enable flow of information between compute agents calibrating data at different frequencies, without actually passing the data, and thereby improving robustness. We present simulation results to show the feasibility as well as the advantages of distribute...

  3. 油罐清洗机器人低压自激脉冲喷嘴的仿真设计%Simulation for Design of Low Pressure Self-Excited Pulsed Nozzle of Oil Tank Cleaning Robots

    Institute of Scientific and Technical Information of China (English)

    何勇强; 周利坤

    2013-01-01

    为实现安全、环保的油罐清洗方式,需要研制配有低压自激脉冲喷嘴的油罐清洗机器人.运用计算流体力学技术,结合油罐清洗的特殊作业环境和罐底油泥特性,对油罐清洗机器人的低压自激脉冲喷嘴进行了仿真设计.通过对自激脉冲射流发生机理和非定常空化模型研究,利用fluent软件对不同的结构设计进行数值仿真,对比分析出不同方案的优劣,选出油罐清洗机器人自激脉冲喷嘴腔径、腔长、上下喷嘴直径、碰撞壁锥度等各结构参数的最优范围,从而为实际设计提供了参考依据.%The oil tank cleaning robots need to be manufactured with low pressure self-excited pulsed nozzle for putting forward a safely and environmentally cleaning mode. By using computional dynamic fluid (CFD) technology, the design of low pressure self—excited pulsed nozzle of the oil tank cleaning robots was simulated for the special working circumstance and the character of oil sludge on the bottom of tank. After the discussion of self—excited pulsation-jet' mechanism and non-steady cavitation model, numerical simulation of different structure designs was carried out using fluent, obtaining the best ranges of self—excited pulsed nozzle' s structure such as cavity diameter, cavity length, upstream and downstream nozzle, and collision board angle. From the contrast and analysis of different blueprints , the basic conclusion for the design came out.

  4. Calibration of the Milagro Cosmic Ray Telescope

    CERN Document Server

    Atkins, R; Berley, D; Chen, M L; Coyne, D G; Delay, R S; Dingus, B L; Dorfan, D E; Ellsworth, R W; Evans, D; Falcone, A D; Fleysher, L; Fleysher, R; Gisler, G; Goodman, J A; Haines, T J; Hoffman, C M; Hugenberger, S; Kelley, L A; Leonor, I; Macri, J R; McConnell, M; McCullough, J F; McEnery, J E; Miller, R S; Mincer, A I; Morales, M F; Némethy, P; Ryan, J M; Schneider, M; Shen, B; Shoup, A L; Sinnis, G; Smith, A J; Sullivan, G W; Thompson, T N; Tümer, T O; Wang, K; Wascko, M O; Westerhoff, S; Williams, D A; Yang, T; Yodh, G B

    1999-01-01

    The Milagro detector is an air shower array which uses the water Cherenkov technique and is capable of continuously monitoring the sky at energies near 1 TeV. The detector consists of 20000 metric tons of pure water instrumented with 723 photo-multiplier tubes (PMTs). The PMTs are arranged in a two-layer structure on a lattice of 3 m spacing covering 5000 $m^2$ area. The direction of the shower is determined from the relative timing of the PMT signals, necessitating a common time reference and amplitude slewing corrections to improve the time resolution. The calibration system to provide these consists of a pulsed laser driving 30 diffusing light sources deployed in the pond to allow cross-calibration of the PMTs. The system is capable of calibrating times and the pulse-heights from the PMTs using the time-over-threshold technique. The absolute energy scale is provided using single muons passing through the detector. The description of the calibration system of the Milagro detector and its prototype Milagrito...

  5. STUCTURE OF PULSED BED

    Directory of Open Access Journals (Sweden)

    I. A. Bokun

    2014-01-01

    Full Text Available The structure of pulsed layer is proposed which can be suggested as a state of particulates that is blown by intermittent gas flow with speed which has the force to start material moving. Layer during one cycle is in a suspension, falling down and immobile state resulting in changes of particles arrangement as well as ways of gas flowing through layer. Moreover, it allows carrying out effective interphase heat exchange even adamant real granulation.The process of formation of impact flows is considered aw well as their influence on formation of air bubbles in pulsed layer. At startup of air blast the balance between the force of hydro-dynamic resistance is broken, on one side, and forces of gravity, particles inertia and their links with walls on the other side. The layer is transferred in the state of pulsed pseudo-fluidization, and presents gas-disperse mixture, inside of which impulse of pressure increasing is spreading to all sides as pressure waves (compression. These waves are the sources of impact flows’ formation, the force of which is two times more than during the stationary flow.The waves of pressure are divided into weak and strong ones depending on movement velocity within gas-disperse system. Weak waves are moving with a sound speed and strong ones in active phase of pulsed layer are moving over the speed of sound limit within gas-disperse system. The peculiarity of strong wave is that parameters of system (pressure, density and others are changing in discrete steps.The article describes the regime of layer’s falling down in the passive stage of cycle, which begins after finishing of gas impulse action. And suspension layer of moving up granular material is transferred in the state of falling resulting in change of the layer structure.

  6. Suppression of transverse ablative Rayleigh-Taylor-like instability in the hole-boring radiation pressure acceleration by using elliptically polarized laser pulses

    CERN Document Server

    Wu, Dong; Qiao, B; Zhou, C T; Yan, X Q; Yu, M Y; He, X T

    2014-01-01

    It is shown that the transverse Rayleigh-Taylor-like (RT) instability in the hole boring radiation pressure acceleration can be suppressed by using elliptically polarized (EP) laser. A moderate ${J}\\times{B}$ heating of the EP laser will thermalize the local electrons, which leads to the transverse diffusion of ions, suppressing the short wavelength perturbations of RT instability. A proper condition of polarization ratio is obtained analytically for the given laser intensity and plasma density. The idea is confirmed by two dimensional Particle-in-Cell simulations, showing that the ion beam driven by the EP laser is more concentrated and intense compared with that of the circularly polarized laser.

  7. Analysis and experimental study on formation conditions of large-scale barrier-free diffuse atmospheric pressure air plasmas in repetitive pulse mode

    Science.gov (United States)

    Li, Lee; Liu, Lun; Liu, Yun-Long; Bin, Yu; Ge, Ya-Feng; Lin, Fo-Chang

    2014-01-01

    Atmospheric air diffuse plasmas have enormous application potential in various fields of science and technology. Without dielectric barrier, generating large-scale air diffuse plasmas is always a challenging issue. This paper discusses and analyses the formation mechanism of cold homogenous plasma. It is proposed that generating stable diffuse atmospheric plasmas in open air should meet the three conditions: high transient power with low average power, excitation in low average E-field with locally high E-field region, and multiple overlapping electron avalanches. Accordingly, an experimental configuration of generating large-scale barrier-free diffuse air plasmas is designed. Based on runaway electron theory, a low duty-ratio, high voltage repetitive nanosecond pulse generator is chosen as a discharge excitation source. Using the wire-electrodes with small curvature radius, the gaps with highly non-uniform E-field are structured. Experimental results show that the volume-scaleable, barrier-free, homogeneous air non-thermal plasmas have been obtained between the gap spacing with the copper-wire electrodes. The area of air cold plasmas has been up to hundreds of square centimeters. The proposed formation conditions of large-scale barrier-free diffuse air plasmas are proved to be reasonable and feasible.

  8. Generation of large-scale, barrier-free diffuse plasmas in air at atmospheric pressure using array wire electrodes and nanosecond high-voltage pulses

    Science.gov (United States)

    Teng, Yun; Li, Lee; Liu, Yun-Long; Liu, Lun; Liu, Minghai

    2014-10-01

    This paper introduces a method to generate large-scale diffuse plasmas by using a repetition nanosecond pulse generator and a parallel array wire-electrode configuration. We investigated barrier-free diffuse plasmas produced in the open air in parallel and cross-parallel array line-line electrode configurations. We found that, when the distance between the wire-electrode pair is small, the discharges were almost extinguished. Also, glow-like diffuse plasmas with little discharge weakening were obtained in an appropriate range of line-line distances and with a cathode-grounding cross-electrode configuration. As an example, we produced a large-scale, stable diffuse plasma with volumes as large as 18 × 15 × 15 cm3, and this discharge region can be further expanded. Additionally, using optical and electrical measurements, we showed that the electron temperature was higher than the gas temperature, which was almost the same as room temperature. Also, an array of electrode configuration with more wire electrodes had helped to prevent the transition from diffuse discharge to arc discharge. Comparing the current waveforms of configurations with 1 cell and 9 cells, we found that adding cells significantly increased the conduction current and the electrical energy delivered in the electrode gaps.

  9. Measurement uncertainty in pulmonary vascular input impedance and characteristic impedance estimated from pulsed-wave Doppler ultrasound and pressure: clinical studies on 57 pediatric patients.

    Science.gov (United States)

    Tian, Lian; Hunter, Kendall S; Kirby, K Scott; Ivy, D Dunbar; Shandas, Robin

    2010-06-01

    Pulmonary vascular input impedance better characterizes right ventricular (RV) afterload and disease outcomes in pulmonary hypertension compared to the standard clinical diagnostic, pulmonary vascular resistance (PVR). Early efforts to measure impedance were not routine, involving open-chest measurement. Recently, the use of pulsed-wave (PW) Doppler-measured velocity to non-invasively estimate instantaneous flow has made impedance measurement more practical. One critical concern remains with clinical use: the measurement uncertainty, especially since previous studies only incorporated random error. This study utilized data from a large pediatric patient population to comprehensively examine the systematic and random error contributions to the total impedance uncertainty and determined the least error prone methodology to compute impedance from among four different methods. We found that the systematic error contributes greatly to the total uncertainty and that one of the four methods had significantly smaller propagated uncertainty; however, even when this best method is used, the uncertainty can be large for input impedance at high harmonics and for the characteristic impedance modulus. Finally, we found that uncertainty in impedance between normotensive and hypertensive patient groups displays no significant difference. It is concluded that clinical impedance measurement would be most improved by advancements in instrumentation, and the best computation method is proposed for future clinical use of the input impedance.

  10. The Science of Calibration

    Science.gov (United States)

    Kent, S. M.

    2016-05-01

    This paper presents a broad overview of the many issues involved in calibrating astronomical data, covering the full electromagnetic spectrum from radio waves to gamma rays, and considering both ground-based and space-based missions. These issues include the science drivers for absolute and relative calibration, the physics behind calibration and the mechanisms used to transfer it from the laboratory to an astronomical source, the need for networks of calibrated astronomical standards, and some of the challenges faced by large surveys and missions.

  11. Dependence of Ba(Zr{sub 0.15}Ti{sub 0.85})O{sub 3} films growth on substrate temperature and oxygen gas pressure prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mahesh, M. L. V., E-mail: mahesh.mlv@gmail.com, E-mail: mahesh@dmrl.drdo.in; James, A. R. [Defence Metallurgical Research Laboratory, Ceramics and Composites Group (India)

    2015-12-15

    Ferroelectric Ba(Zr{sub 0.15}Ti{sub 0.85})O{sub 3} (BZT) thin films were deposited on Pt/Ti/SiO{sub 2}/Si <111> substrates using Pulsed Laser Deposition technique. The effect of processing parameters such as substrate temperature and oxygen gas pressure on the structural properties of the films was analyzed. The experimental results showed that the films deposited at substrate temperature ≥600 °C, exhibited crystalline nature corresponding to perovskite phase structure. The mechanism explaining the dependence of the crystallinity of the BZT films on the substrate temperature is discussed. AFM data show the dependence of grain growth on oxygen partial pressure of the BZT thin films. The films deposited at 200 mT were found to have an average grain size of about 40 nm. The results were found to be in accordance with SEM analysis. Raman scattering spectral data were used to characterize the phonon modes of the BZT films at room temperature. Raman studies reveal the occurrence of multiple phases corresponding to the pinched-phase transition, reported to be possessed by the composition under study.

  12. Pulse Voltammetry.

    Science.gov (United States)

    Osteryoung, Janet

    1983-01-01

    Discusses the nature of pulse voltammetry, indicating that its widespread use arises from good sensitivity and detection limits and from ease of application and low cost. Provides analytical and mechanistic applications of the procedure. (JN)

  13. Dynamic calibration and validation of an accelerometer force balance for hypersonic lifting models.

    Science.gov (United States)

    Singh, Prakash; Trivedi, Sharad; Menezes, Viren; Hosseini, Hamid

    2014-01-01

    An accelerometer-based force balance was designed and developed for the measurement of drag, lift, and rolling moment on a blunt-nosed, flapped delta wing in a short-duration hypersonic shock tunnel. Calibration and validation of the balance were carried out by a convolution technique using hammer pulse test and surface pressure measurements. In the hammer pulse test, a known impulse was applied to the model in the appropriate direction using an impulse hammer, and the corresponding output of the balance (acceleration) was recorded. Fast Fourier Transform (FFT) was operated on the output of the balance to generate a system response function, relating the signal output to the corresponding load input. Impulse response functions for three components of the balance, namely, axial, normal, and angular, were obtained for a range of input load. The angular system response function was corresponding to rolling of the model. The impulse response functions thus obtained, through dynamic calibration, were operated on the output (signals) of the balance under hypersonic aerodynamic loading conditions in the tunnel to get the time history of the unknown aerodynamic forces and moments acting on the model. Surface pressure measurements were carried out on the model using high frequency pressure transducers, and forces and moments were deduced thereon. Tests were carried out at model angles of incidence of 0, 5, 10, and 15 degrees. A good agreement was observed among the results of different experimental methods. The balance developed is a comprehensive force/moment measurement device that can be used on complex, lifting, aerodynamic geometries in ground-based hypersonic test facilities.

  14. OLI Radiometric Calibration

    Science.gov (United States)

    Markham, Brian; Morfitt, Ron; Kvaran, Geir; Biggar, Stuart; Leisso, Nathan; Czapla-Myers, Jeff

    2011-01-01

    Goals: (1) Present an overview of the pre-launch radiance, reflectance & uniformity calibration of the Operational Land Imager (OLI) (1a) Transfer to orbit/heliostat (1b) Linearity (2) Discuss on-orbit plans for radiance, reflectance and uniformity calibration of the OLI

  15. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Fernandez Garcia, Sergio; Villanueva, Héctor

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and correspondi...

  16. Sandia WIPP calibration traceability

    Energy Technology Data Exchange (ETDEWEB)

    Schuhen, M.D. [Sandia National Labs., Albuquerque, NM (United States); Dean, T.A. [RE/SPEC, Inc., Albuquerque, NM (United States)

    1996-05-01

    This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

  17. WFPC2 Polarization Calibration

    Science.gov (United States)

    Biretta, J.; McMaster, M.

    1997-12-01

    We derive a detailed calibration for WFPC2 polarization data which is accurate to about 1.5%. We begin by computing polarizer flats, and show how they are applied to data. A physical model for the polarization effects of the WFPC2 optics is then created using Mueller matricies. This model includes corrections for the instrumental polarization (diattenuation and phase retardance) of the pick-off mirror, as well as the high cross-polarization transmission of the polarizer filter. We compare this model against the on-orbit observations of polarization calibrators, and show it predicts relative counts in the different polarizer/aperture settings to 1.5% RMS accuracy. We then show how this model can be used to calibrate GO data, and present two WWW tools which allow observers to easily calibrate their data. Detailed examples are given illustrationg the calibration and display of WFPC2 polarization data. In closing we describe future plans and possible improvements.

  18. Magnetic Linear Birefringence Measurements Using Pulsed Fields

    CERN Document Server

    Berceau, Paul; Battesti, Remy; Rizzo, Carlo

    2011-01-01

    In this paper we present the accomplishment of the further step towards the vacuum magnetic birefringence measurement based on pulsed fields. After describing our BMV experiment, we report the calibration of our apparatus with nitrogen gas and we discuss the precision of our measurement giving a detailed error budget. Our best present vacuum sensitivity is 2.1x 10^-19 T^-2 per 5 ms magnetic pulse. We finally discuss the perspectives to reach our final goal.

  19. 老年原发性高血压患者晨峰与脉搏波传导速度相关性研究%Association between morning blood pressure surge and pulse wave velocity in elderly hypertensive subjects

    Institute of Scientific and Technical Information of China (English)

    胡小亮; 路方红; 刘振东; 赵颖馨; 孙尚文; 王舒健; 潘慧; 李俊

    2011-01-01

    目的 探讨老年高血压患者血压晨峰与颈桡动脉脉搏波传导速度(crPWV)的相关性.方法 选择老年原发性高血压患者159例,根据24 h动态血压结果,将患者分为晨峰组(95例)和非晨峰组(64例).2组行crPWV检测,并测血生化.结果 晨峰组crPWV明显高于非晨峰组[(11.5±1.7)m/s vs(9.1±1.6)m/s,P<0.01].crPWV与血压晨峰(r=0.787,P<0.01)、24 h收缩压(r=0.649,P<0.01)、年龄(r=0.437,P<0.01)、空腹血糖(r=0.293,P<0.05)及LDL-c(r=0.354,P<0.05)呈正相关;以crPWV为应变量,年龄、高血压病程、体重指数、空腹血糖、24 h收缩压及舒张压、LDL-C、TC、TG、HDL-C、血压晨峰为自变量,进行多元线性逐步回归分析,血压晨峰、24 h收缩压、年龄为crPWV独立影响因素.结论 血压晨峰与动脉粥样硬化密切相关.%objective To investigate the association between morning blood pressure (MBPS) and carotid-radial pulse wave velocity(crPWV) ,in elderly patients with essential hypertension. Method According to the results of 24 h ambulatory blood pressure monitoring, 159 patients were divided in to the morning surge group(MBPS group,n= 95) and non-morning blood pressure surge group(nMBPS group, n= 64). Carotid-radial pulse wave velocity, blood glucose and lipid profiles were recorded. Results The crPWV of the MBPS group was significantly higher than that of the nMBPS group[(11.5±1.7)m/s vs (9. 1±1. 6)m/s,P<0. 01]. Pearson relation analysis showed that crPWV level positively correlated with MBPS(r=0. 787,P<0. 01),the average of 24 h SBP (r=0. 649,P<0. 01) ,age(r=0. 437,P<0. 01),FPG(r=0. 293,P<0. 05) and LDL-C(r=0. 354, P<0. 05); Multiple linear regression showed that MBPS were significant and independent factors for crPWV in elderly patients with essential hypertension. Conclusion The study showed that MBPS was closely related with atherosclerosis in patients with essential hypertension,suggesting it is justified for concurrent inhibition of morning blood

  20. 不同压力对TC4钛合金真空脉冲渗氮的影响%Influence of Different Pressure on Vacuum Pulse Nitriding of TC4 Titanium Alloy

    Institute of Scientific and Technical Information of China (English)

    杨闯; 刘静; 马亚芹; 洪流

    2015-01-01

    目的:采用不同压力对TC4钛合金进行真空脉冲渗氮处理,提高其表面硬度及耐磨性。方法通过金相显微镜、X射线衍射仪、显微硬度计及耐磨试验机分析渗氮硬化层的组织与性能。结果 TC4钛合金经过真空气体渗氮处理后,形成了由TiN,Ti2 AlN和钛铝金属间化合物Ti3 Al组成的复合改性层。渗氮压力太低,表面氮化物数量较少,氮化物层较薄;随渗氮压力的增大,表面氮化物数量增多,表面硬度及耐磨性增加。压力为0.015 MPa时,氮化物层表面硬度最大,表面硬度为1100~1200HV,有效硬化层深度为50~60μm。渗氮压力继续增加,表层组织变得疏松,表面硬度及耐磨性开始降低。结论选择合适的渗氮压力和表面氮浓度进行真空脉冲渗氮,可以提高钛合金表面硬度,改善耐磨性。%ABSTRACT:Objective Vacuum pulse nitriding treatment at different pressure was applied to TC4 titanium alloy to improve sur-face hardness and wear resistance. Methods The microstructure and properties of hardened layer were analyzed by metallurgical microscopy, X-ray diffraction (XRD), microhardness tester and wear testing machine. Results The surface composite modified layer composed of TiN, Ti2 AlN and Ti3 Al was obtained by vacuum nitriding treatment of TC4 titanium alloy. Low nitriding pressure led to the low number of surface nitrides and the low thickness of the nitriding layer. With the increase of pressure, the number of nitrides increased, the surface hardness and wear resistance also increased. The surface hardness reached the maximum value at 0. 015 MPa. The surface hardness of nitrided TC4 titanium was 1100~1200HV, and the thickness of the effective hardened layer reached 50~60 μm. With further increase of nitriding pressure, the microstructure became loose, the surface hardness and wear resistance began to decrease. Conclusion Vacuum pulse nitriding treatment under suitable pressure and suitable concentration of

  1. 高血压患者动态脉压指数与冠状动脉病变的相关性分析%Correlation between ambulatory pulse pressure indexes and coronary artery lesions in patients with hypertension

    Institute of Scientific and Technical Information of China (English)

    冯玉平; 石慧荣; 赵立平

    2013-01-01

    Objective To investigate the correlation between ambulatory pulse pressure indexes (APPI) and coronary artery disease (CHD) in patients with hypertension. Methods The hypertensive patients (n=355) with coronary angiography (CAG) were chose from Apr. 2010 to Apr. 2013 and then divided into CHD group (n=237) and non-CHD group (n=118) according to CAG resutls. All patients were given 24-hour ambulatory blood pressure monitoring. The changes of SBP, DBP and pulse pressure (PP) were recorded and mean pressure [MBP=(SBP+DBP)/2] and PP index (PPI=PP/SBP) were calculated. The correlation between the above mentioned indexes and coronary artery lesions was analyzed. Results The levels of PP and APPI were higher in CHD group than those in non-CHD group [PP:(77.8±8.7) mmHg vs. (64.7±7.6) mmHg;APPI:(0.52±0.08) vs. (0.45±0.10) , P<0.05]. In CHD patients, the higher APPI value, the more severe coronary artery lesions (P<0.01). The results of Logistic analysis showed that APPI (OR=1.39), PP (OR=1.23) and SBP (OR=1.27) were risk factors of CHD (all P<0.01). Conclusion APPI value can be used for predict the severity of coronary artery lesions in patients with hypertension.%目的探讨高血压患者动态脉压指数(pluse pressure index,PPI)与冠状动脉病变的相关性。方法纳入2010年4月~2013年4月实施冠状动脉造影(CAG)的高血压患者355例。根据CAG结果将患者分为冠心病组(n=237)及非冠心病组(n=118)。对所有研究对象均进行24 h动态血压监测,记录收缩压(SBP)、舒张压(DBP)和脉压(PP),计算脉压指数(PPI,PPI=PP/SBP)。分析上述因素与冠状动脉病变的相关性。结果与非冠心病组相比,冠心病组患者PP及PPI水平更高,分别为(77.8±8.7)mmHg vs.(64.7±7.6)mmHg,(0.52±0.08) vs.(0.45±0.10),差异有统计学意义(P<0.05)。在冠心病患者中,PPI值越高,患者冠脉病变数值越高(P<0.01

  2. Influence of structural parameters on performance of monopropellant pulse thruster with high chamber pressure%结构参数对单组元高室压脉冲推力器的性能影响

    Institute of Scientific and Technical Information of China (English)

    覃粒子; 郭志海; 娄德全; 梁树强

    2012-01-01

    高室压脉冲火箭发动机由于使用差动式可移动喷注器,能够得到比供给压强高得多的燃烧室压强.为了分析其工作特性,建立了单组元脉冲火箭发动机挤压喷注、燃烧、排气过程的集总参数模型,以硝酸羟铵(HAN)基作为单组元推进剂,采用四阶龙格-库塔法对模型进行求解.分别从喷注器喷孔面积、喷注器差动面积比、喷管喉部面积、喷注器行程等方面分析并总结了结构参数对单组元高室压脉冲发动机性能的影响规律及影响程度.结果表明:计算模型能反映发动机的实际工作过程,其中,喷注器行程对燃烧室平均压强和平均比冲的影响最大,平均推力则对喷管喉部面积的变化最为敏感,上述两个结构参数是发动机优化设计时的首要考虑因素;其他结构参数对发动机也存在不同程度的影响,可以作为次要因素来考虑.%Due to the movable injector which can be regarded as a differential piston with some spray holes,the pulse thruster can provide much higher chamber pressure than the supply pressure of propellant.In order to analyze the operating characteristics of this type of pulse thruster adopting the monopropellant of HAN(hydroxylammonium nitrate),a lumped parameter model was established and the fourth-order Runge-Kutta method was applied to get its numerical solution which reflected the unique pulsating characteristics.The influence of the structural parameters on the thruster performance such as the area of injection holes,nozzle throat area,displacement and differential area ratio of the movable injector was analyzed and summarized.Though the pulsating operation would come to change when any of the above parameters is altered,the displacement and the nozzle throat area are the most influential and should be optimized firstly in the design progress of the new type of pulse thruster.The average pressure in the combustion chamber and the average specific

  3. Self-pulsing of a micro thin cathode discharge

    CERN Document Server

    Gebhardt, Markus; Hemke, Torben; Brinkmann, Ralf Peter; Mussenbrock, Thomas

    2011-01-01

    Microplasmas operated at atmospheric pressure show a number of peculiar dynamic phenomena. One of these phenomena is self-pulsing, which is characterized by intrinsic pulsing behavior of a DC driven plasma discharge. This work focuses on the numerical simulation of self-pulsing in a micro thin cathode discharge operated in atmospheric pressure argon. By means of a hybrid plasma model we show self-pulsing of the discharge in the expected MHz frequency range and described its actual origin.

  4. Two-photon absorption laser induced fluorescence measurement of atomic oxygen density in an air atmospheric pressure plasma jet

    Science.gov (United States)

    Conway, Jim; Gogna, Gurusharan; Daniels, Stephen

    2016-09-01

    Two-photon Absorption Laser Induced Fluorescence (TALIF) is used to measure atomic oxygen number density [O] in an air Atmospheric Pressure Plasma Jet (APPJ). A novel technique based on photolysis of O2 is used to calibrate the TALIF system ensuring the same species (O) is probed during calibration and measurement. As a result, laser intensity can be increased outside the TALIF quadratic laser power region without affecting calibration reliability as any high intensity saturation effects will be identical for calibration and experiment. Higher laser intensity gives stronger TALIF signals helping overcome weak TALIF signals often experienced at atmospheric pressure due to collisional quenching. O2 photo-dissociation and two-photon excitation of the resulting [O] are both achieved within the same laser pulse. The photolysis [O] is spatially non-uniform and time varying. To allow valid comparison with [O] in a plasma, spatial and temporal correction factors are required. Knowledge of the laser pulse intensity I0(t), and wavelength allows correction factors to be found using a rate equation model. The air flow into the jet was fixed and the RF power coupled into the system varied. The resulting [O] was found to increase with RF power.

  5. Segment Based Camera Calibration

    Institute of Scientific and Technical Information of China (English)

    马颂德; 魏国庆; 等

    1993-01-01

    The basic idea of calibrating a camera system in previous approaches is to determine camera parmeters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration in whih camera parameters are determined by a set of 3D lines.A set of constraints is derived on camea parameters in terms of perspective line mapping.Form these constraints,the same perspective transformation matrix as that for point mapping can be computed linearly.The minimum number of calibration lines is 6.This result generalizes that of Liu,Huang and Faugeras[12] for camera location determination in which at least 8 line correspondences are required for linear computation of camera location.Since line segments in an image can be located easily and more accurately than points,the use of lines as calibration reference tends to ease the computation in inage preprocessing and to improve calibration accuracy.Experimental results on the calibration along with stereo reconstruction are reported.

  6. Pulse plating

    CERN Document Server

    Hansal, Wolfgang E G; Green, Todd; Leisner, Peter; Reichenbach, Andreas

    2012-01-01

    The electrodeposition of metals using pulsed current has achieved practical importance in recent years. Although it has long been known that changes in potential, with or without polarity reversal, can significantly affect the deposition process, the practical application of this has been slow to be adopted. This can largely be explained in terms of the complex relationship between the current regime and its effect on the electrodeposition process. In order to harness these effects, an understanding of the anodic and cathodic electrochemical processes is necessary, together with the effects of polarity reversal and the rate of such reversals. In this new monograph, the basics of metal electrodeposition from solution are laid out in great detail in seven distinct chapters. With this knowledge, the reader is able to predict how a given pulse train profile can be adopted to achieve a desired outcome. Equally important is the choice of a suitable rectifier and the ancillary control circuits to enable pulse platin...

  7. Relationship between pulse pressure and urine microalbuminuria in the elderly with essential hypertension%老年高血压患者脉压与微量白蛋白尿的关系

    Institute of Scientific and Technical Information of China (English)

    朱长琪; 杨静

    2012-01-01

    Objective To study the relationship between pulse pressure and urine microalbuminuria in aged patients with hypertension. Methods 131 elderly hypertesion patients with normal serum urea nitrogen ( Bun) , creati-nine (Cr)and 24h urine protein were divided into four groups by the level of pulse pressure (PP) ( 70 mmHg). Urine albumin were determined by immunonephelometric methud. Results Among the four groups, the levels of UAER increased gradually with the PP levels (P < 0. 01). Conclusion PP is one of the high risk factors of renal damage in patients with hypertension.%目的 研究老年高血压患者脉压与微量白蛋白尿之间的关系.方法 将131例老年原发性高血压患者根据脉压水平分为4组(< 50 mm Hg,50~ 59 mm Hg,60 ~69 mm Hg,>70 mm Hg),所有患者入选时血尿素氮、肌酐和24 h尿蛋白总量均在正常范围内.取晨尿用免疫散射法测定尿白蛋白含量,计算尿白蛋白排泄率(UAER).结果 25例脉压<50 mm Hg者,UAER为(3.5±1.2) μg/min;31例脉压50 ~60 mm Hg者,UAER为(9.3±7.2) μg,/min;23例脉压60~70 mm Hg者,UAER为(29.6±32.1)g/min;52例脉压70 mm Hg以上者,UAER为(51.7±31.8) μg/min.随着脉压的增高,老年高血压患者的UAER也随之增高.结论 脉压可作为老年高血压患者肾损害的高危预测指标之一.

  8. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Courtney, Michael

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and corresponding...... lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from the reference lidar measurements are given for information only....

  9. Site Calibration report

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    This report describes the site calibration carried out at Østerild, during a given period. The site calibration was performed with two Windcube WLS7 (v1) lidars at ten measurements heights. The lidar is not a sensor approved by the current version of the IEC 61400-12-1 [1] and therefore the site...... calibration with lidars does not comply with the standard. However, the measurements are carried out following the guidelines of IEC 61400-12-1 where possible, but with some deviations presented in the following chapters....

  10. Absolute calibration of a multilayer-based XUV diagnostic

    CERN Document Server

    Stuik, R; Tümmler, J; Bijkerk, F

    2002-01-01

    A portable, universal narrowband XUV diagnostic suitable for calibration of various XUV light sources, was built, tested and fully calibrated. The diagnostic allows measurement of the absolute XUV energy and average power in two selected wavelength bands, at 11.4 and 13.4 nm. In addition, the pulse-to-pulse and long-term XUV stability of the source can be assessed, as well as the contamination of multilayer XUV optics exposed to the source. This paper describes the full calibration procedure: all optical elements were calibrated at the wavelength of operation by Physikalisch-Technische Bundesanstalt at the storage ring Bessy II, a full analysis of geometrical factors was done, and the influence of the spectral emissivity of the source on the calibration was analyzed in detail. The calibration was performed both for the centroid wavelength as for the full bandwidth of the diagnostic. The total uncertainty in the absolute calibration allowed measurement of source characteristics with an uncertainty of less than...

  11. Calibration Fixture For Anemometer Probes

    Science.gov (United States)

    Lewis, Charles R.; Nagel, Robert T.

    1993-01-01

    Fixture facilitates calibration of three-dimensional sideflow thermal anemometer probes. With fixture, probe oriented at number of angles throughout its design range. Readings calibrated as function of orientation in airflow. Calibration repeatable and verifiable.

  12. New in-situ, non-intrusive calibration

    Science.gov (United States)

    Zunino, Heather; Adrian, Ronald; Ding, Liuyang; Prestridge, Kathy

    2014-11-01

    Tomographic particle image velocimetry (PIV) experiments require precise and accurate camera calibration. Standard techniques make assumptions about hard-to-measure camera parameters (i.e. optical axis angle, distortions, etc.)-reducing the calibration accuracy. Additionally, vibrations and slight movements after calibration may cause significant errors-particularly for tomographic PIV. These problems are exacerbated when a calibration target cannot be placed within the test section. A new PIV camera calibration method has been developed to permit precise calibration without placing a calibration target inside the test section or scanning the target over a volume. The method is capable of correcting for dynamic calibration changes occurring between PIV laser pulses. A transparent calibration plate with fine marks on both sides is positioned on the test section window. Dual-plane mapping makes it possible to determine a mapping function containing both position and angular direction of central rays from particles. From this information, central rays can be traced into the test section with high accuracy. Image distortion by the lens and refraction at various air-glass-liquid interfaces are accounted for, and no information about the position or angle of the camera(s) is required.

  13. Correlation between diurnal variation of intraocular pressure, ocular pulse amplitude and corneal structural properties Correlação entre a variação diurna da pressão intraocular, amplitude de pulso e propriedades estruturais corneanas

    Directory of Open Access Journals (Sweden)

    Flávia Silva Villas-Bôas

    2009-06-01

    Full Text Available PURPOSE: The purpose of this study was to evaluate the fluctuation of intraocular pressure measurements obtained by Goldmann applanation tonometry, dynamic contour tonometry, and corneal compensated non-contact tonometry during office hours in glaucoma and healthy participants. This study also aims at correlating the intraocular pressure fluctuations with fluctuations of corneal hysteresis, central corneal thickness, mean central corneal curvature and ocular pulse amplitude. METHODS: A total of 12 controls (24 eyes and 21 patients (38 eyes with open-angle glaucoma were recruited. Intraocular pressure measured by Goldmann applanation tonometry, dynamic contour tonometry and corneal compensated non-contact tonometry, ocular pulse amplitude, central corneal curvature and thickness, corneal hysteresis, and resistance factor were obtained at intervals of 2 hours, between 9 AM and 5 PM. RESULTS: Intraocular pressure fluctuated significantly throughout the day in controls and glaucoma individuals with all tonometers (POBJETIVO: Avaliar a flutuação das medidas da pressão intraocular obtidas pela tonometria de aplanação de Goldmann, tonometria de contorno dinâmico e pela tonometria de não-contato com compensação corneana durante o período ambulatorial, em participantes com glaucoma e saudáveis. Esse estudo também correlacionou as flutuações da pressão intraocular com as flutuações da histerese corneana, espessura corneana central, média da curvatura corneana central e amplitude de pulso ocular. MÉTODOS: Um total de 12 controles (24 olhos e 21 pacientes com glaucoma de ângulo aberto (38 olhos foram selecionados. A pressão intraocular medida pela tonometria de aplanação de Goldmann, tonometria de contorno dinâmico e tonometria de não-contato com compensação corneana, amplitude de pulso ocular, a curvatura central e espessura corneanas, a histerese corneana e o fator de resistência foram medidos em intervalos de 2 horas, entre 9

  14. Calibration of CR-39 with monoenergetic protons

    Science.gov (United States)

    Xiaojiao, Duan; Xiaofei, Lan; Zhixin, Tan; Yongsheng, Huang; Shilun, Guo; Dawei, Yang; Naiyan, Wang

    2009-10-01

    Calibration of solid state nuclear track detector CR-39 was carried out with very low-energy monoenergetic protons of 20-100 keV from a Cockcroft Walton accelerator. To reduce the beam of the proton from the accelerator, a novel method was adopted by means of a high voltage pulse generator. The irradiation time of the proton beam on each CR-39 sheet was shortened to one pulse with duration of 100 ns, so that very separated proton tracks around 104 cm-2 can be irradiated and observed and measured on the surface of the CR-39 detector after etching. The variations of track diameter with etching time as well as with proton energy response curve has been carefully calibrated for the first time in this very low energy region. The calibration shows that the optical limit for the observation of etched tracks of protons in CR-39 is about or a little lower that 20 keV, above which the proton tracks can be seen clearly and the response curve can be used to distinguish protons from the other ions and determine the energy of the protons. The extension of response curve of protons from traditionally 20 to 100 keV in CR-39 is significant in retrieving information of protons produced in the studies of nuclear physics, plasma physics, ultrahigh intensity laser physics and laser acceleration.

  15. SPOTS Calibration Example

    Directory of Open Access Journals (Sweden)

    Patterson E.

    2010-06-01

    Full Text Available The results are presented using the procedure outlined by the Standardisation Project for Optical Techniques of Strain measurement to calibrate a digital image correlation system. The process involves comparing the experimental data obtained with the optical measurement system to the theoretical values for a specially designed specimen. The standard states the criteria which must be met in order to achieve successful calibration, in addition to quantifying the measurement uncertainty in the system. The system was evaluated at three different displacement load levels, generating strain ranges from 289 µstrain to 2110 µstrain. At the 289 µstrain range, the calibration uncertainty was found to be 14.1 µstrain, and at the 2110 µstrain range it was found to be 28.9 µstrain. This calibration procedure was performed without painting a speckle pattern on the surface of the metal. Instead, the specimen surface was prepared using different grades of grit paper to produce the desired texture.

  16. Air Data Calibration Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is for low altitude subsonic altimeter system calibrations of air vehicles. Mission is a direct support of the AFFTC mission. Postflight data merge is...

  17. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina; Webb, Craig

    2016-05-02

    This presentation provides a high-level overview of the progress on the Broadband Outdoor Radiometer Calibrations for all shortwave and longwave radiometers that are deployed by the Atmospheric Radiation Measurement program.

  18. SRHA calibration curve

    Data.gov (United States)

    U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...

  19. Calibrating nacelle lidars

    DEFF Research Database (Denmark)

    Courtney, Michael

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report...... presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail. The first of these is a line of sight calibration method in which both lines of sight (for a two beam lidar) are individually calibrated...... a representative distribution of radial wind speeds. An alternative method is to place the nacelle lidar on the ground and incline the beams upwards to bisect a mast equipped with reference instrumentation at a known height and range. This method will be easier and faster to implement and execute but the beam...

  20. NASA Glenn Icing Research Tunnel: 2014 Cloud Calibration

    Science.gov (United States)

    VanZante, Judith Foss; Ide, Robert F.; Steen, Laura; Acosta, Waldo J.

    2014-01-01

    The results of the December 2013 to February 2014 Icing Research Tunnel full icing cloud calibration are being presented to the SAE AC-9C committee, as represented in the 2014 cloud calibration report. The calibration steps included establishing a uniform cloud and conducting drop size and liquid water content calibrations. The goal of the calibration was to develop a uniform cloud, and to generate a transfer function from the inputs of air speed, spray bar atomizing air pressure and water pressure to the outputs of median volumetric drop diameter and liquid water content. This was done for both 14 CFR Parts 25 and 29, Appendix C (typical icing) and soon-to-be released Appendix O (supercooled large drop) conditions.

  1. Newly developed apparatus for calibration of quadrupole mass spectrometer

    Science.gov (United States)

    Meng, Dong; Yongjun, Cheng; Detian, Li; Wenjun, Sun; Lan, Zhao; Meiru, Guo; Yongjun, Wang; Huzhong, Zhang; Yanwu, Li; Gang, Li

    2017-01-01

    In this paper, a new calibration apparatus has been developed for calibrating quadrupole mass spectrometer (QMS) from 10-8 Pa to 10-2 Pa for He, N2 and Ar. Based on the apparatus, two calibration methods are introduced to generate standard pressure P i ‧ (or P i ″) of lower than 10-2 Pa, which are named as ‘the SRG measurement method’ and ‘the CDG measurement method’. The SRG measurement method can generate a standard pressure range from 10-8 Pa to 10-5 Pa, and the CDG measurement method can generate a standard pressure range from 10-5 Pa to 10-2 Pa. A molecular flow condition is determined and a QMS is calibrated by the two methods using single gas and mixture gas. The gas flow through the small tube and orifice realizes molecular flow at an upstream pressure of less than 70 Pa. The sensitivities calibration results with the two methods agree well, and the difference is less than 3%. The sensitivity calibrated with single gas is different from that calibrated with mixture gas. Obtained results are roughly consistent with those of previous studies.

  2. Calibrating nacelle lidars

    OpenAIRE

    Courtney, Michael

    2013-01-01

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail.The first of these is a line of sight...

  3. TWSTFT Link Calibration Report

    Science.gov (United States)

    2015-09-01

    box calibrator with unknown but constant total delay during a calibration tour Total Delay: The total electrical delay from the antenna phase center...to the UTCp including all the devices/cables that the satellite and clock signals pass through. It numerically equals the sum of all the sub-delays...PTB. To average out the dimnal effects and measurement noise , 5-7 days of continuous measurements is required. 3 Setups at the Lab(k) The setup

  4. Magnetic Pulse Welding Technology

    Directory of Open Access Journals (Sweden)

    Ahmad K. Jassim

    2011-12-01

    Full Text Available In this paper, the benefits of using Magnetic Pulse machine which is belong to Non-conventional machine instead of conventional machine. Magnetic Pulse Technology is used for joining dissimilar metals, and for forming and cutting metals. It is a non contact technique. Magnetic field is used to generate impact magnetic pressure for welding and forming the work piece by converted the electrical energy to mechanical energy. It is enable us to design previously not possible by welding dissimilar materials and allowing to welds light and stronger materials together. It can be used to weld metallic with non metallic materials to created mechanical lock on ceramics, polymers, rubbers and composites. It is green process; there is no heat, no radiation, no gas, no smoke and sparks, therefore the emissions are negligible.

  5. Calibrating nacelle lidars

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, M.

    2013-01-15

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail. The first of these is a line of sight calibration method in which both lines of sight (for a two beam lidar) are individually calibrated by accurately aligning the beam to pass close to a reference wind speed sensor. A testing procedure is presented, reporting requirements outlined and the uncertainty of the method analysed. It is seen that the main limitation of the line of sight calibration method is the time required to obtain a representative distribution of radial wind speeds. An alternative method is to place the nacelle lidar on the ground and incline the beams upwards to bisect a mast equipped with reference instrumentation at a known height and range. This method will be easier and faster to implement and execute but the beam inclination introduces extra uncertainties. A procedure for conducting such a calibration is presented and initial indications of the uncertainties given. A discussion of the merits and weaknesses of the two methods is given together with some proposals for the next important steps to be taken in this work. (Author)

  6. Magnetic sensor for arterial distension and blood pressure monitoring.

    Science.gov (United States)

    Ruhhammer, Johannes; Herbstritt, Tamara; Ruh, Dominic; Foerster, Katharina; Heilmann, Claudia; Beyersdorf, Friedhelm; Goldschmidtboeing, Frank; Seifert, Andreas; Woias, Peter

    2014-12-01

    A novel sensor for measuring arterial distension, pulse and pressure waveform is developed and evaluated. The system consists of a magnetic sensor which is applied and fixed to arterial vessels without any blood vessel constriction, hence avoiding stenosis. The measurement principle could be validated by in vitro experiments on silicone tubes, and by in vivo experiments in an animal model, thereby indicating the non-linear viscoelastic characteristics of real blood vessels. The sensor is capable to provide absolute measurements of the dynamically varying arterial diameter. By calibrating the sensor, a long-term monitoring system for continuously measuring blood pressure and other cardiovascular parameters could be developed based on the method described. This will improve diagnostics for high risk patients and enable a better, specific treatment.

  7. Influence of the reactive atmosphere on the formation of nanoparticles in the plasma plume induced by nanosecond pulsed laser irradiation of metallic targets at atmospheric pressure and high repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Girault, M. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078 Dijon Cedex (France); Le Garrec, J.-L.; Mitchell, J.B.A. [Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 35042 Rennes Cedex (France); Jouvard, J.-M. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078 Dijon Cedex (France); Carvou, E. [Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 35042 Rennes Cedex (France); Menneveux, J.; Yu, J. [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France); Ouf, F.-X. [Institut de Radioprotection et de Sureté Nucléaire IRSN/PSN-RES/SCA/LPMA BP 68, 91192 Gif-Sur-Yvette (France); Carles, S. [Institut de Physique de Rennes, UMR 6251 CNRS-Université de Rennes 1, 35042 Rennes Cedex (France); Potin, V.; Pillon, G.; Bourgeois, S. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078 Dijon Cedex (France); Perez, J. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette Cedex (France); Marco de Lucas, M.C., E-mail: delucas@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Univ. Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47 870, F-21078 Dijon Cedex (France); and others

    2016-06-30

    Highlights: • NPs formed in a plasma-plume during laser irradiation of metals (Al, Ti, Ag) were studied. • In situ SAXS and ex situ TEM, XRD and Raman spectra were measured. • NPs size decreased when increasing the O{sub 2} fraction in a controlled O{sub 2}+N{sub 2} atmosphere. • The oxidation of metal NPs in the plasma restricts the increase of the size of the NPs. - Abstract: The influence of a reactive atmosphere on the formation of nanoparticles (NPs) in the plasma plume generated by nanosecond pulsed laser irradiation of metal targets (Ti, Al, Ag) was probed in situ using Small Angle X-ray Scattering (SAXS). Air and different O{sub 2}–N{sub 2} gas mixtures were used as reactive gas within atmospheric pressure. SAXS results showed the formation of NPs in the plasma-plume with a mean radius varying in the 2–5 nm range. A decrease of the NPs size with increasing the O{sub 2} percentage in the O{sub 2}–N{sub 2} gas mixture was also showed. Ex situ observations by transmission electron microscopy and structural characterizations by X-ray diffraction and Raman spectroscopy were also performed for powders collected in experiments done using air as ambient gas. The stability of the different metal oxides is discussed as being a key parameter influencing the formation of NPs in the plasma-plume.

  8. Heat driven pulse pump

    Science.gov (United States)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  9. Radioxenon detector calibration spike production and delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P.; Cameron, Ian M.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.; Kriss, Aaron A.; Lidey, Lance S.; Mendez, Jennifer M.; Prinke, Amanda M.; Riedmann, Robin A.

    2016-03-01

    Abstract Beta-Gamma coincidence radioxenon detectors must be calibrated for each of the four-radioxenon isotopes (135Xe, 133Xe, 133mXe, and 131mXe). Without a proper calibration, there is potential for the misidentification of the amount of each isotope detected. It is important to accurately determine the amount of each radioxenon isotope, as the ratios can be used to distinguish between an anthropogenic source and a nuclear explosion. We have developed a xenon calibration system (XeCalS) that produces calibration spikes of known activity and pressure for field calibration of detectors. The activity concentrations of these calibration spikes are measured using a beta-gamma coincidence detector and a high purity germanium (HPGe) detector. We will present the results from the development and commissioning of XeCalS, along with the future plans for a portable spike implementation system.

  10. Microprocessor-based single particle calibration of scintillation counter

    Science.gov (United States)

    Mazumdar, G. K. D.; Pathak, K. M.

    1985-01-01

    A microprocessor-base set-up is fabricated and tested for the single particle calibration of the plastic scintillator. The single particle response of the scintillator is digitized by an A/D converter, and a 8085 A based microprocessor stores the pulse heights. The digitized information is printed. Facilities for CRT display and cassette storing and recalling are also made available.

  11. Optical relative calibration and stability monitoring for the Auger fluorescence detector

    Energy Technology Data Exchange (ETDEWEB)

    Aramo, Carla; Brack, J.; Caruso, R.; D' Urso, D.; Fazio, D.; Fonte, R.; Gemmeke, H.; Kleifges, M.; Knapik, R.; Insolia, A.; /Catania U.; Matthews, J.A.J.; Menshikov, A.; Miller, W.; Privitera, P.; Rodriguez Martino, J.

    2005-07-01

    The stability of the fluorescence telescopes of the Pierre Auger Observatory is monitored with the optical relative calibration setup. Optical fibers distribute light pulses to three different diffuser groups within the optical system. The total charge per pulse is measured for each pixel and compared with reference calibration measurements. This allows monitoring the short and long term stability with respect of the relative timing between pixels and the relative gain for each pixel. The designs of the LED calibration unit (LCU) and of the Xenon flash lamp used for relative calibration, are described and their capabilities to monitor the stability of the telescope performances are studied. We report the analysis of relative calibration data recorded during 2004. Fluctuations in the relative calibration constants provide a measure of the stability of the FD.

  12. 中青年高血压合并不稳定心绞痛患者动态脉压、脉压指数与 MMP-9、Hs-CRP 的相关性%Relationship between ambulatory pulse pressure and pulse pressure index with MMP-9 and Hs-CRP in middle-aged patients with hypertension and unstable angina pectoris

    Institute of Scientific and Technical Information of China (English)

    刘冬梅; 谢艳凤; 马丽; 苗昌荣; 王晓蕊; 赵紫英

    2016-01-01

    目的:观察中青年高血压合并不稳定心绞痛患者动态脉压、脉压指数水平的变化,并探讨其与血清基质金属蛋白酶-9(MMP-9)、超敏 C 反应蛋白(Hs-CRP)水平的关系。方法选择中青年高血压合并不稳定心绞痛患者102例作为观察组,采用酶联免疫吸附法(ELISA)测定 MMP-9与 Hs-CRP 水平,选择同期健康体检者94例为对照组。将观察组按动态脉压进行分层,分为41~60 mmHg、61~80 mmHg、≥81 mmHg 3个水平;脉压指数进行分层,分为 APPI≤0.400、0.401~0.500、≥0.5013个水平;比较不同动态脉压和脉压指数水平时MMP-9、Hs-CRP 水平的变化,并进行 MMP-9与 Hs-CRP 之间的直线相关和回归分析。结果观察组 MMP-9、Hs-CRP 水平明显高于对照组;动态脉压与脉压指数水平越大,观察组血清 MMP-9、Hs-CRP 水平越高;直线相关和回归分析表明,MMP-9与 Hs-CRP 呈显著正相关。结论血清 MMP-9、Hs-CRP 水平升高与中青年高血压合并不稳定心绞痛密切相关;动态脉压、脉压指数与 MMP-9、Hs-CRP 密切相关。%Objective To observe the ambulatory pulse pressure(APP)and pulse pressure index(APPI)in the middle-aged patients with hypertension and unstable angina pectoris(UAP),and to probe into relationship between ambulatory pulse pressure(APP)and pulse pressure index(APPI)with matrix metalloproteinase-9(MMP-9)and High-sensitive C-reactive protein(Hs-CRP). Methods The 102 middle-aged patients with hypertension and UAP were the observation group,in which levels of MMP-9 and Hs-CRP were examined by eyzyme-linked immuno sorbent assay(ELISA). In the same period,94 healthy physical examinees were included in the control group. The observation group were divided into 3 layers according to the level of APP(41-60 mmHg,61-80 mmHg,≥81mmHg respective-ly);According to the level of APPI,there were also three layers(≤0. 400,0. 401-0. 500,≥0. 501 respectively)in the

  13. Plasma response to transient high voltage pulses

    Indian Academy of Sciences (India)

    S Kar; S Mukherjee

    2013-07-01

    This review reports on plasma response to transient high voltage pulses in a low pressure unmagnetized plasma. Mainly, the experiments are reviewed, when a disc electrode (metallic and dielectric) is biased pulsed negative or positive. The main aim is to review the electron loss in plasmas and particle balance during the negative pulse electrode biasing, when the applied pulse width is less than the ion plasma period. Though the applied pulse width is less than the ion plasma period, ion rarefaction waves are excited. The solitary electron holes are reviewed for positive pulsed bias to the electrode. Also the excitation of waves (solitary electron and ion holes) is reviewed for a metallic electrode covered by a dielectric material. The wave excitation during and after the pulse withdrawal, excitation and propagation characteristics of various electrostatic plasma waves are reviewed here.

  14. Development of neutron calibration field using accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Mamoru [Tohoku Univ., Cyclotron and Radioisotope Center, Sendai, Miyagi (Japan)

    2003-03-01

    A brief summary is given on the fast neutron calibration fields for 1) 8 keV to 15 MeV range, and 2) 30-80 MeV range. The field for 8 keV to 15 MeV range was developed at the Fast Neutron Laboratory (FNL) at Tohoku University using a 4.5 MV pulsed Dynamitron accelerator and neutron production reactions, {sup 45}Sc(p, n), {sup 7}Li(p, n), {sup 3}H(p, n), D(d, n) and T(d, n). The latter 30-80 MeV fields are setup at TIARA of Takasaki Establishment of Japan Atomic Energy Research Institute, and at Cyclotron Radio Isotope Center (CYRIC) of Tohoku University using a 90 MeV AVF cyclotron and the {sup 7}Li(p, n) reaction. These fields have been applied for various calibration of neutron spectrometers and dosimeters, and for irradiation purposes. (author)

  15. Responsivity Calibration of Pyroelectric Terahertz Detectors

    CERN Document Server

    Berry, Christopher W; Jarrahi, Mona

    2014-01-01

    There has been a significant advancement in terahertz radiation sources in the past decade, making milliwatt terahertz power levels accessible in both continuous-wave and pulsed operation. Such high-power terahertz radiation sources circumvent the need for cryogenic-cooled terahertz detectors such as semiconductor bolometers and necessitate the need for new types of calibrated, room-temperature terahertz detectors. Among various types of room-temperature terahertz detectors, pyroelectric detectors are one of the most widely used detectors, which can offer wide dynamic range, broad detection bandwidth, and high sensitivity levels. In this article, we describe the calibration process of a commercially available pyroelectric detector (Spectrum Detector, Inc, SPI-A-65 THz), which incorporates a 5 mm diameter LiTaO3 detector with an organic terahertz absorber coating.

  16. NASA Glenn Icing Research Tunnel: 2012 Cloud Calibration Procedure and Results

    Science.gov (United States)

    VanZante, Judith Foss; Ide, Robert F.; Steen, Laura E.

    2012-01-01

    In 2011, NASA Glenn s Icing Research Tunnel underwent a major modification to it s refrigeration plant and heat exchanger. This paper presents the results of the subsequent full cloud calibration. Details of the calibration procedure and results are presented herein. The steps include developing a nozzle transfer map, establishing a uniform cloud, conducting a drop sizing calibration and finally a liquid water content calibration. The goal of the calibration is to develop a uniform cloud, and to build a transfer map from the inputs of air speed, spray bar atomizing air pressure and water pressure to the output of median volumetric droplet diameter and liquid water content.

  17. Pulsed thermoelectricity

    Science.gov (United States)

    Apostol, M.; Nedelcu, M.

    2010-07-01

    A special mechanism of thermoelectric transport is described, consisting of pulses of charge carriers which "fly" periodically through the external circuit from the hot end of the sample to the cold end, with a determined duration of the "on" and "off" times of the electric contacts, while maintaining continuously the thermal contacts. It is shown that such a "resonant" ideal thermogenerator may work cyclically, with the same efficiency quotient as the ideal efficiency quotient of the thermoelectric devices operated in the usual stationary transport regime but the electric flow and power are increased, as a consequence of the concentration of the charge carriers on pulses of small spatial extent. The process is reversible, in the sense that it can be operated either as a thermoelectric generator or as an electrothermal cooler.

  18. Calibration Under Uncertainty.

    Energy Technology Data Exchange (ETDEWEB)

    Swiler, Laura Painton; Trucano, Timothy Guy

    2005-03-01

    This report is a white paper summarizing the literature and different approaches to the problem of calibrating computer model parameters in the face of model uncertainty. Model calibration is often formulated as finding the parameters that minimize the squared difference between the model-computed data (the predicted data) and the actual experimental data. This approach does not allow for explicit treatment of uncertainty or error in the model itself: the model is considered the %22true%22 deterministic representation of reality. While this approach does have utility, it is far from an accurate mathematical treatment of the true model calibration problem in which both the computed data and experimental data have error bars. This year, we examined methods to perform calibration accounting for the error in both the computer model and the data, as well as improving our understanding of its meaning for model predictability. We call this approach Calibration under Uncertainty (CUU). This talk presents our current thinking on CUU. We outline some current approaches in the literature, and discuss the Bayesian approach to CUU in detail.

  19. In situ ``artificial plasma'' calibration of tokamak magnetic sensors

    Science.gov (United States)

    Shiraki, D.; Levesque, J. P.; Bialek, J.; Byrne, P. J.; DeBono, B. A.; Mauel, M. E.; Maurer, D. A.; Navratil, G. A.; Pedersen, T. S.; Rath, N.

    2013-06-01

    A unique in situ calibration technique has been used to spatially calibrate and characterize the extensive new magnetic diagnostic set and close-fitting conducting wall of the High Beta Tokamak-Extended Pulse (HBT-EP) experiment. A new set of 216 Mirnov coils has recently been installed inside the vacuum chamber of the device for high-resolution measurements of magnetohydrodynamic phenomena including the effects of eddy currents in the nearby conducting wall. The spatial positions of these sensors are calibrated by energizing several large in situ calibration coils in turn, and using measurements of the magnetic fields produced by the various coils to solve for each sensor's position. Since the calibration coils are built near the nominal location of the plasma current centroid, the technique is referred to as an "artificial plasma" calibration. The fitting procedure for the sensor positions is described, and results of the spatial calibration are compared with those based on metrology. The time response of the sensors is compared with the evolution of the artificial plasma current to deduce the eddy current contribution to each signal. This is compared with simulations using the VALEN electromagnetic code, and the modeled copper thickness profiles of the HBT-EP conducting wall are adjusted to better match experimental measurements of the eddy current decay. Finally, the multiple coils of the artificial plasma system are also used to directly calibrate a non-uniformly wound Fourier Rogowski coil on HBT-EP.

  20. Calibration Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L.; Broocks, Bryan T.; Phillips, Mark C.

    2006-02-01

    The Calibration Systems project at Pacific Northwest National Laboratory (PNNL) is aimed towards developing and demonstrating compact Quantum Cascade (QC) laser-based calibration systems for infrared imaging systems. These on-board systems will improve the calibration technology for passive sensors, which enable stand-off detection for the proliferation or use of weapons of mass destruction, by replacing on-board blackbodies with QC laser-based systems. This alternative technology can minimize the impact on instrument size and weight while improving the quality of instruments for a variety of missions. The potential of replacing flight blackbodies is made feasible by the high output, stability, and repeatability of the QC laser spectral radiance.

  1. Ibis ground calibration

    Energy Technology Data Exchange (ETDEWEB)

    Bird, A.J.; Barlow, E.J.; Tikkanen, T. [Southampton Univ., School of Physics and Astronomy (United Kingdom); Bazzano, A.; Del Santo, M.; Ubertini, P. [Istituto di Astrofisica Spaziale e Fisica Cosmica - IASF/CNR, Roma (Italy); Blondel, C.; Laurent, P.; Lebrun, F. [CEA Saclay - Sap, 91 - Gif sur Yvette (France); Di Cocco, G.; Malaguti, E. [Istituto di Astrofisica Spaziale e Fisica-Bologna - IASF/CNR (Italy); Gabriele, M.; La Rosa, G.; Segreto, A. [Istituto di Astrofisica Spaziale e Fisica- IASF/CNR, Palermo (Italy); Quadrini, E. [Istituto di Astrofisica Spaziale e Fisica-Cosmica, EASF/CNR, Milano (Italy); Volkmer, R. [Institut fur Astronomie und Astrophysik, Tubingen (Germany)

    2003-11-01

    We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system.

  2. TARGETLESS CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2012-09-01

    Full Text Available In photogrammetry a camera is considered calibrated if its interior orientation parameters are known. These encompass the principal distance, the principal point position and some Additional Parameters used to model possible systematic errors. The current state of the art for automated camera calibration relies on the use of coded targets to accurately determine the image correspondences. This paper presents a new methodology for the efficient and rigorous photogrammetric calibration of digital cameras which does not require any longer the use of targets. A set of images depicting a scene with a good texture are sufficient for the extraction of natural corresponding image points. These are automatically matched with feature-based approaches and robust estimation techniques. The successive photogrammetric bundle adjustment retrieves the unknown camera parameters and their theoretical accuracies. Examples, considerations and comparisons with real data and different case studies are illustra