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Sample records for high pressure pulsed

  1. Piston cylinder cell for high pressure ultrasonic pulse echo measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kepa, M. W., E-mail: mkepa@staffmail.ed.ac.uk; Huxley, A. D. [SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Ridley, C. J.; Kamenev, K. V. [Centre for Science at Extreme Conditions and School of Engineering, University of Edinburgh, Edinburgh EH9 3FD (United Kingdom)

    2016-08-15

    Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe{sub 2}.

  2. 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.......2 kcal.mol−1) and OH+OH (tentatively 8 kJ·mol−1, 1.9 kcal·mol−1) have been determined. The absorption spectrum of the OH radical has been determined up to temperatures of 200°C. The absorption maximum is found at 230 nm at all temperatures. The reaction between Fe2+ and OH radicals has been studied up...... to a temperature of 220°C. An activation energy of 9 kJ·mol−1 (2.2 kcal·mol−1) has been determined and the spectrum of the transient formed in the reaction has been determined at different temperatures....

  3. 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 k...

  4. 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.

  5. Pulsed laser kinetic studies of liquids under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1993-06-21

    Experiments have been developed for measuring the rates of chemical reactions liquids and in supercritical Co[sub 2]. A pulsed (Q-switch) Nd:YAG laser at 355 nm was the pump beam for laser flash photolysis studies of molybdenum and tungsten hexacarbonyls undergoing ligand displacement reactions by bidentate chelating agents such as 2,2[prime]-bipyridine in toluene. Experiments were carried out at 0.1 to 150 MPa. In the case of molybdenum complexes, the reaction mechanism for thermal ring closure is found from activation volumes to change from associative interchange to dissociative interchange as substituents on the 2,2[prime]-bipyridine ligands become bulkier. In a similar study of more rigid, substituted phenanthroline bidentate ligands it was found that substituent bulkiness had little effect on the thermal ring closure mechanism. Similar high pressure flash photolysis experiments with tungsten hexacarbonyl have also been completed. The concentration dependence of the fluorescence and nonradiative decay quantum yields for cresyl violet in several solvent have been reported as well as stability constants for the complexation of lithium ion by four different crown ethers dissolved in a room temperature molten salt.

  6. Kinetics of high pressure argon-helium pulsed gas discharge

    Science.gov (United States)

    Emmons, D. J.; Weeks, D. E.

    2017-05-01

    Simulations of a pulsed direct current discharge are performed for a 7% argon in helium mixture at a pressure of 270 Torr using both zero- and one-dimensional models. Kinetics of species relevant to the operation of an optically pumped rare-gas laser are analyzed throughout the pulse duration to identify key reaction pathways. Time dependent densities, electron temperatures, current densities, and reduced electric fields in the positive column are analyzed over a single 20 μs pulse, showing temporal agreement between the two models. Through the use of a robust reaction rate package, radiation trapping is determined to play a key role in reducing A r (1 s5) metastable loss rates through the reaction sequence A r (1 s5)+e-→A r (1 s4)+e- followed by A r (1 s4)→A r +ℏω . Collisions with He are observed to be responsible for A r (2 p9) mixing, with nearly equal rates to A r (2 p10) and A r (2 p8) . Additionally, dissociative recombination of A r2+ is determined to be the dominant electron loss mechanism for the simulated discharge conditions and cavity size.

  7. Pulsed laser kinetic studies of liquids under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1991-11-25

    A high pressure apparatus constructed for measuring the rates of reactions in liquids under pressures ranging from 1 atm to 2000 atm has been used to measure the complexation kinetics of molybdenum hexacarbonyl reacting with 2,2-bipyridine, 4,4{prime}-dimethyl-2-2{prime}-bipyridine and 4,4{prime}-diphenyl-2-2{prime} bipyridine in toluene. Pentacarbonyl reaction intermediates are created by a 10 nsec flash of frequency tripled Nd:YAG laser light. Measured activation volumes for chelate ligand ring closure indicate a change in mechanism from associative interchange to dissociative interchange as steric hindrance increases. A similar high pressure kinetics study of molybdenum carbonyl complexation by several substituted phenanthrolines is now well advanced that indicates that with the more rigid phenanthroline ligands steric effects from bulky substituents have less effect on the ring closure mechanism than in the case of the bipyridine ligands. An experimental concentration dependence of the fluorescence quantum yield of cresyl violet has been harmonized with previously published contradictory reports. Fluorescence of cresyl violet in various solvents and in micellar systems has also been systematically explored.

  8. PIEZOELECTRIC WAVEGUIDE SENSOR FOR MEASURING PULSE PRESSURE IN CLOSED LIQUID VOLUMES AT HIGH VOLTAGE ELECTRIC DISCHARGE

    Directory of Open Access Journals (Sweden)

    V. G. Zhekul

    2017-10-01

    Full Text Available Purpose. Investigations of the characteristics of pressure waves presuppose the registration of the total profile of the pressure wave at a given point in space. For these purposes, various types of «pressure to the electrical signal» transmitters (sensors are used. Most of the common sensors are unsuitable for measuring the pulse pressure in a closed water volume at high hydrostatic pressures, in particular to study the effect of a powerful high-voltage pulse discharge on increasing the inflow of minerals and drinking water in wells. The purpose of the work was to develop antijamming piezoelectric waveguide sensor for measuring pulse pressure at a close distance from a high-voltage discharge channel in a closed volume of a liquid. Methodology. We have applied the calibration method as used as a secondary standard, the theory of electrical circuits. Results. We have selected the design and the circuit solution of the waveguide pressure sensor. We have developed a waveguide pulse-pressure sensor DTX-1 with a measuring loop. This sensor makes it possible to study the spectral characteristics of pressure waves of high-voltage pulse discharge in closed volumes of liquid at a hydrostatic pressure of up to 20 MPa and a temperature of up to 80 °C. The sensor can be used to study pressure waves with a maximum amplitude value of up to 150 MPa and duration of up to 80 µs. According to the results of the calibration, the sensitivity of the developed sensor DTX-1 with a measuring loop is 0.0346 V/MPa. Originality. We have further developed the theory of designing the waveguide piezoelectric pulse pressure sensors for measuring the pulse pressure at a close distance from a high-voltage discharge channel in a closed fluid volume by controlling the attenuation of the amplitude of the pressure signal. Practical value. We have developed, created, calibrated, used in scientific research waveguide pressure pulse sensors DTX-1. We propose sensors DTX-1 for sale

  9. 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.

  10. 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%.

  11. 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...

  12. Pulsed laser kinetic studies of liquids under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1992-09-22

    A laser flash photolysis kinetic study of 2,2{prime}-bipyridine bidentate chelating ligands with one claw in the first coordination sphere of a molybdenum carbonyl complex has been completed at pressures up to 150 MPa. The reaction mechanism for thermal ring closure is found from activation volumes to change from associative interchange to dissociative interchange as substituents on the 2,2{prime}-bipyridine ligands become bulkier. In a similar study of more rigid, substituted phenanthroline bidentate ligands it was found that substituent bulkiness had little effect on the thermal ring closure mechanism. Stability constants for lithium ion complexes with crown ethers in a room temperature molten salt, fluorescence quantum yields for cresyl violet and several other dyes in solution, and the oxidation of alcohols by OsO{sub 4} have also been investigated.

  13. Isentropic compression of metals, at multi-megabar pressures, using high explosive pulsed power

    Energy Technology Data Exchange (ETDEWEB)

    Tasker, D. G. (Douglas G.); Goforth, J. H. (James H.); King, J. C. (James Carrel); Martinez, E. C. (Ernesto C.); Oona, H. (Hain); Sena, F. C. (Francis C.); Reisman, D. B. (David B.); Cauble, R. C. (Robert C.)

    2001-01-01

    Accurate, ultra-high pressure isentropic equation of state (EOS) data, are required for a variety of applications and materials. Asay reported a new method to obtain these data using pulsed magnetic loading on the Sandia Z-machine. Fast rising current pulses (risetimes from 100 to 30011s) at current densities exceeding many MNcm, create continuous magnetic loading up to a few Mbar. As part of a collaborative effort between the Los Alamos and Lawrence Livermore National Laboratories we are adapting our high explosive pulsed power (HEPP) methods to obtain isentropic EOS data with the Asay technique. This year we plan to obtain isentropic EOS data for copper and tantalum at pressures up to -2 Mbar; eventually we hope to reach several tens of Mbar. We will describe the design of the HEPP systems and show out attempts to obtain EOS data to date.

  14. Pulsed Supersonic Beams from High Pressure Source: Simulation Results and Experimental Measurements

    Directory of Open Access Journals (Sweden)

    U. Even

    2014-01-01

    Full Text Available Pulsed beams, originating from a high pressure, fast acting valve equipped with a shaped nozzle, can now be generated at high repetition rates and with moderate vacuum pumping speeds. The high intensity beams are discussed, together with the skimmer requirements that must be met in order to propagate the skimmed beams in a high-vacuum environment without significant disruption of the beam or substantial increases in beam temperature.

  15. Effect of high-hydrostatic pressure and moderate-intensity pulsed electric field on plum.

    Science.gov (United States)

    García-Parra, J; González-Cebrino, F; Delgado-Adámez, J; Cava, R; Martín-Belloso, O; Élez-Martínez, P; Ramírez, R

    2018-03-01

    Moderate intensity pulse electric fields were applied in plum with the aim to increase bioactive compounds content of the fruit, while high-hydrostatic pressure was applied to preserve the purées. High-hydrostatic pressure treatment was compared with an equivalent thermal treatment. The addition of ascorbic acid during purée manufacture was also evaluated. The main objective of this study was to assess the effects on microorganisms, polyphenoloxidase, color and bioactive compounds of high-hydrostatic pressure, or thermal-processed plum purées made of moderate intensity pulse electric field-treated or no-moderate intensity pulse electric field-treated plums, after processing during storage. The application of moderate intensity pulse electric field to plums slightly increased the levels of anthocyanins and the antioxidant activity of purées. The application of Hydrostatic-high pressure (HHP) increased the levels of bioactive compounds in purées, while the thermal treatment preserved better the color during storage. The addition of ascorbic acid during the manufacture of plum purée was an important factor for the final quality of purées. The color and the bioactive compounds content were better preserved in purées with ascorbic acid. The no inactivation of polyphenoloxidase enzyme with treatments applied in this study affected the stability purées. Probably more intense treatments conditions (high-hydrostatic pressure and thermal treatment) would be necessary to reach better quality and shelf life during storage.

  16. Explosive Processes on Cathode while Forming Nanosecond Pulsed Discharge of High Pressure

    National Research Council Canada - National Science Library

    A. Hashimov; R. Mekhtizadeh; А. Bondyakov; Sh. Kazimov

    2012-01-01

    ...) while forming nanosecond pulsed discharge in dense air. Influence of field and air pressure heterogeneity rate in gas gap on size of micro-craters being formed on working cathode surface after pulsed effect has been shown in the paper...

  17. High pulse pressure and metabolic syndrome are associated with proteinuria in young adult women

    Science.gov (United States)

    2013-01-01

    Background Obesity and metabolic syndrome play causative roles in the increasing prevalence of proteinuria in the general population. However, in young adult women the clinical significance of incidentally discovered proteinuria and its association with metabolic syndrome are unclear. We investigated the prevalence and risk factors for proteinuria in this population. Methods A total of 10,385 women aged 20 to 39 years who underwent health screenings were surveyed. Each patient was tested for proteinuria with a dipstick (−, ±, 1+, 2+, or 3+), and proteinuria was defined as 1+ or greater. Persistent proteinuria was established by confirming proteinuria in a subsequent test. Metabolic syndrome was defined in accordance with the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asia. Results The mean age was 28.9 ± 5.5 years, and the prevalence of persistent proteinuria was 1.0%. Among these subjects with persistent proteinuria, obesity and metabolic syndrome were found in 10.4% and 5.2%, respectively. Metabolic syndrome, as well as its components of hypertension, hyperglycemia, central obesity, low high-density lipoprotein levels, and high triglyceride levels, was closely related to the presence of proteinuria. In addition, a wide pulse pressure of ≥40 mmHg was another independent risk factor for proteinuria [odds ratio (OR) 3.29, 95% confidence interval (CI) 1.03–11.91)]. This had an additive effect on metabolic syndrome in terms of predicting proteinuria. Even in subjects without metabolic syndrome, the influence of an increased pulse pressure was consistent (OR 2.75, 95% CI 1.03–8.61). Conclusions Specific attention to proteinuria may be necessary in asymptomatic young women aged 20 to 39 years if they have metabolic syndrome or a wide pulse pressure. PMID:23433013

  18. 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.

  19. Tunable time-reversal cavity for high-pressure ultrasonic pulses generation: A tradeoff between transmission and time compression

    Science.gov (United States)

    Arnal, Bastien; Pernot, Mathieu; Fink, Mathias; Tanter, Mickael

    2012-08-01

    This Letter presents a time reversal cavity that has both a high reverberation time and a good transmission factor. A multiple scattering medium has been embedded inside a fluid-filled reverberating cavity. This allows creating smart ultrasonic sources able to generate very high pressure pulses at the focus outside the cavity with large steering capabilities. Experiments demonstrate a 25 dB gain in pressure at the focus. This concept will enable us to convert conventional ultrasonic imaging probes driven by low power electronics into high power probes for therapeutic applications requiring high pressure focused pulses, such as histotripsy or lithotripsy.

  20. High performance pulse generator

    Science.gov (United States)

    Grothaus, Michael G.; Moran, Stuart L.; Hardesty, Leonard W.

    1992-06-01

    The device is a compact Marx-type generator capable of producing a high-voltage burst of pulses having risetimes less than 10 nanoseconds at repetition rates up to 10 kHz. High-pressure hydrogen switches are used as the switching elements to achieve high rep-rate. A small coaxial design provides low inductance and a fast risetime. The device may be used as a high-rep-rate high-voltage trigger generator, or as a high-voltage pulse source capable of producing up to 1 MV pulses at high repetition rates.

  1. Very High Pressure Single Pulse Shock Tube Studies of Aromatic Species

    Energy Technology Data Exchange (ETDEWEB)

    Brezinsky, K.

    2006-11-28

    The principal focus of this research program is aimed at understanding the oxidation and pyrolysis chemistry of primary aromatic molecules and radicals with the goal of developing a comprehensive kinetic model at conditions that are relevant to practical combustion devices. A very high pressure single pulse shock tube is used to obtain experimental data over a wide pressure range in the high pressure regime, 5-1000 bars, at pre-flame temperatures for fuel pyrolysis and oxidation over a broad spectrum of equivalence ratios. Stable species sampled from the shock tube are analyzed using standard chromatographic techniques using GC/MS-PDD and GC/TCD-FID. Experimental data from the HPST (stable species profiles) and data from other laboratories (if available) are simulated using kinetic models (if available) to develop a comprehensive model that can describe aromatics oxidation and pyrolysis over a wide range of experimental conditions. The shock tube has been heated (1000C) recently to minimize effects due to condensation of aromatic, polycyclic and other heavy species. Work during this grant period has focused on 7 main areas summarized in the final technical report.

  2. Explosive Processes on Cathode while Forming Nanosecond Pulsed Discharge of High Pressure

    Directory of Open Access Journals (Sweden)

    A. Hashimov

    2012-01-01

    Full Text Available The paper is devoted to research of cathode surfaces with different curvature radius (r = 1–8 mm while forming nanosecond pulsed discharge in dense air. Influence of field and air pressure heterogeneity rate in gas gap on size of micro-craters being formed on working cathode surface after pulsed effect has been shown in the paper. The paper reveals a maximum expansion of separate micro-crater size on cathode surface with small curvature radius.

  3. Direct injection of high pressure gas : scaling properties of pulsed turbulent jets

    NARCIS (Netherlands)

    Baert, R.S.G.; Klaassen, A.; Doosje, E.

    2010-01-01

    Existing gasoline DI injection equipment has been modified to generate single hole pulsed gas jets. Injection experiments have been performed at combinations of 3 different pressure ratios (2 of which supercritical) respectively 3 different hole geometries (i.e. length to diameter ratios). Injection

  4. 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.

  5. Electrical breakdown and optical emission properties of high pressure pulsed RF gas discharges

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, S.R.; Hurst, G.S. [Pellissippi International, Oak Ridge, TN (United States)]|[Consultec Scientific, Inc., Knoxville, TN (United States); Gibson, W.A. [Pellissippi International, Oak Ridge, TN (United States); Turner, J.E.; Hamm, R.N. [Oak Ridge National Lab., TN (United States); Wright, H.A. [Consultec Scientific, Inc., Knoxville, TN (United States)

    1994-06-01

    A fundamentally new technique for the measurement of the number of subexcitation electrons produced by the passage of ionizing radiation through a gas has ben developed by us during the past few years. The new detector is based on the digital characterization of the electrons in the particle track produced by the ionizing radiation where the charged particle track is registered by measuring the number of electrons found in given subvolumes of the gas in the ionization chamber. The track is thus characterized by a set of integers in each volume clement, from which parameters such as the track length and energy can be measured. We have specifically developed this technique for use in the field of microdosimetry, where the study of the fluctuations in the energy deposition in the charged particle track on the order of the molecular to cellular dimensions is important in understanding the chemical and biological effects of ionizing radiation. If the charged particle is a recoil nucleus produced by a neutron interaction, the energy deposited and the linear energy transfer can be inferred from this information, allowing the detector to act as neutron spectrometer. In this paper the experimental apparatus used to make these measurements and the optical and pulsed RF electric field optimization we have performed are described. Images of particle tracks produced by {alpha} and {beta} particles, and recoil protons from the interaction of high energy neutrons with hydrogenous materials, are also presented to illustrate the sensitivity and track imaging resolution. The quality of the information gained from the detector is a very sensitive function of the gas mixture constituents, purities and pressures used in the chamber, along with the magnitude, duration, and frequency of the pulsed RF electric field.

  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. 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.

  8. 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.

  9. Physical Kinetics of Electrons in a High-Voltage Pulsed High-Pressure Discharge with Cylindrical Geometry

    Science.gov (United States)

    Kozhevnikov, V. Yu.; Kozyrev, A. V.; Semeniuk, N. S.

    2017-12-01

    Results of theoretical modeling of the phenomenon of a high-voltage discharge in nitrogen at atmospheric pressure are presented, based on a consistent kinetic theory of the electrons. A mathematical model of a nonstationary high-pressure discharge has been constructed for the first time, based on a description of the electron component from first principles. The physical kinetics of the electrons are described with the help of the Boltzmann kinematic equation for the electron distribution function over momenta with only ionization and elastic collisions taken into account. A detailed spatiotemporal picture of a nonstationary discharge with runaway electrons under conditions of coaxial geometry of the gas diode is presented. The model describes in a self-consistent way both the process of formation of the runaway electron flux in the discharge and the influence of this flux on the rate of ionization processes in the gas. Total energy spectra of the electron flux incident on the anode are calculated. The obtained parameters of the current pulse of the beam of fast electrons correlate well with the known experimental data.

  10. 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

  11. The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-G-P, Alejandro [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Schneider, Christof W., E-mail: christof.schneider@psi.ch [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Döbeli, Max [Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland); Lippert, Thomas; Wokaun, Alexander [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland)

    2015-12-01

    Highlights: • The flip-over effect in PLD is observed up to high deposition pressures. • Consistent congruent transfer of the target composition is generally not correct. • The choice of deposition pressure can change the film composition strongly. • Large compositional changes appear at high off-axis angles and large spot sizes. - Abstract: In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion. This effect has been mainly reported for vacuum depositions of single element targets and is particularly noticeable when the aspect ratio of the beam spot is large. We investigate the flip-over effect in vacuum and at three relevant background-gas pressures for pulsed laser deposition using a La{sub 0.4}Ca{sub 0.6}MnO{sub 3} target by measuring the thickness dependence of the deposited material as a function of angle. The film thicknesses and compositions are determined by Rutherford backscattering and argon is used to reduce the influence of additional chemical reactions in the plasma. The results show the prevalence of the flip-over effect for all pressures except for the highest, i.e. 1 × 10{sup −1} mbar, where the film thickness is constant for all angles. The composition profiles show noticeable compositional variations of up to 30% with respect to the target material depending on the background gas pressure, the angular location, and the laser spot dimensions.

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

    Science.gov (United States)

    2014-12-17

    The Journal of Chemical Physics , (08 2011): 1. doi: 10.1063/1.3626860 13.00 23.00 20.00 18.00 17.00 16.00 15.00 24.00 38.00 08/30/2011 08/30/2011...diagram, The Journal of Chemical Physics , (05 2011): 1. doi: 10.1063/1.3574009 Andrew Kung, Alexander F. Goncharov, Chang sheng Zha, Peter Eng...Wendy L. Mao. Compressional, temporal, and compositional behavior of H2-O2 compound formed by high pressure x-ray irradiation, The

  13. Swept-Ramp Detonation Initiation Performance in a High-Pressure Pulse Detonation Combustor

    Science.gov (United States)

    2010-12-01

    e. N2 Tank – OPEN 26. Cooling Water Pump a. Test Cell #3 Knife Switch – ON b. Knife Switch Breaker Handle – ON c. Water Tank – CHECK (full and...Test Cell #2 Ball Valve – CLOSED b. Water Tank Isolation Valve – CLOSED c. Knife Switch Breaker Handle – OFF d. Test Cell #3 Knife Switch – OFF 21...December 2009. 68 [12] Kistler Instrument Corporation, Type 603B1 Miniature , High Frequency, Charge Output Pressure Sensor Data Sheet, 2003. 69

  14. Pulse pressure and diurnal blood pressure variation

    DEFF Research Database (Denmark)

    Knudsen, Søren Tang; Poulsen, Per Løgstrup; Hansen, Klavs Würgler

    2002-01-01

    BACKGROUND: In nondiabetic subjects pulse pressure (PP) is an independent predictor of cardiovascular disease and microalbuminuria. Reduced circadian blood pressure (BP) variation is a potential risk factor for the development of diabetic complications. We investigated the association between...... retinopathy, nephropathy, macrovascular disease, PP, and diurnal BP variation in a group of type 2 diabetic patients. METHODS: In 80 type 2 diabetic patients we performed 24-h ambulatory BP (AMBP) and fundus photographs. Urinary albumin excretion was evaluated by urinary albumin/creatinine ratio. Presence...... or absence of macrovascular disease was assessed by an independent physician. RESULTS: Forty-nine patients had no detectable retinal changes (grade 1), 13 had grade 2 retinopathy, and 18 had more advanced retinopathy (grades 3-6). Compared to patients without retinopathy (grade 1), patients with grades 2...

  15. Ignition and afterglow dynamics of a high pressure nanosecond pulsed helium micro-discharge: II. Rydberg molecules kinetics

    Science.gov (United States)

    Carbone, Emile A. D.; Schregel, Christian-Georg; Czarnetzki, Uwe

    2016-10-01

    In this paper, we discuss the experimental results presented in Schregel et al (2016 Plasma Sources Sci. Technol. 25 054003) on a high pressure micro-discharge operated in helium and driven by nanosecond voltage pulses. A simple global plasma chemistry model is developed to describe the ions, excited atomic and molecular species dynamics in the ignition and early afterglow regimes. The existing experimental data on high pressure helium kinetics is reviewed and critically discussed. It is highlighted that several inconsistencies in the branching ratio of neutral assisted associative and dissociative processes currently exist in the literature and need further clarification. The model allows to pinpoint the mechanisms responsible for the large amounts of Rydberg molecules produced in the discharge and for the helium triplet metastable state in the afterglow. The main losses of electrons are also identified. The fast quenching of excited He (n  >  3) states appears to be a significant source of Rydberg molecules which has been previously neglected. The plasma model finally draws a simplified, but still accurate description of high pressure helium discharges based on available experimental data for ion and neutral helium species.

  16. 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)

  17. Method for detecting and distinguishing between specific types of environmental radiation using a high pressure ionization chamber with pulse-mode readout

    Energy Technology Data Exchange (ETDEWEB)

    Degtiarenko, Pavel V.

    2017-12-19

    An environmental radiation detector for detecting and distinguishing between all types of environmental radiation, including photons, charged particles, and neutrons. A large volume high pressure ionization chamber (HPIC) includes BF.sub.3 gas at a specific concentration to render the radiation detector sensitive to the reactions of neutron capture in Boron-10 isotope. A pulse-mode readout is connected to the ionization chamber capable of measuring both the height and the width of the pulse. The heavy charged products of the neutron capture reaction deposit significant characteristic energy of the reaction in the immediate vicinity of the reaction in the gas, producing a signal with a pulse height proportional to the reaction energy, and a narrow pulse width corresponding to the essentially pointlike energy deposition in the gas. Readout of the pulse height and the pulse width parameters of the signals enables distinguishing between the different types of environmental radiation, such as gamma (x-rays), cosmic muons, and neutrons.

  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. 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.

  20. High pulse pressure is related to risk of type 2 diabetes mellitus in Chinese middle-aged females.

    Science.gov (United States)

    Zhang, Lu; Wang, Bingyuan; Wang, Chongjian; Li, Linlin; Ren, Yongcheng; Zhang, Hongyan; Yang, Xiangyu; Zhao, Yang; Han, Chengyi; Zhou, Junmei; Luo, Xinping; Hu, Dongsheng

    2016-10-01

    To examine the association of risk of incident type 2 diabetes mellitus (T2DM) with high pulse pressure (PP) by sex. We performed a prospective cohort study of 12,272 eligible participants (4664 males and 7608 females) without diabetes at baseline. Participants were classified as having normal PP (20-60mmHg) and high PP (>60mmHg) at baseline. The analysis was further stratified by sex, quartiles of age and high PP categories. During 6years of follow-up, T2DM developed in 775 participants and the incidence was 10.57/1000person-years. With PP 70 to 76mmHg, the multivariable adjusted hazard ratio (HR) (95% confidence interval) for incident T2DM in females was 1.722 (1.093-2.714) after adjustment for baseline age, smoking, alcohol intake, physical activity level and family history of T2DM, and 1.634 (1.037-2.575) after adjustment for the above factors and body mass index, waist circumference, blood lipid levels and fasting plasma glucose (FPG) category. After stratification by quartiles of age, for females aged 52 to 59, the multivariable adjusted HRs (95% CI) for high PP as compared to normal PP were 2.263 (1.517-3.377) and 2.140 (1.426-3.210) in different models. During follow-up, levels of FPG, fasting plasma insulin and homeostatic model assessment of insulin resistance index (HOMA-IR) were higher in females with higher than normal PP group, but β-cell function was impaired in the high PP group (P<0.05). High PP may be related to incident T2DM among female in China, especially women 52 to 59years old. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. 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

  2. Pulsed laser kinetic studies of liquids under high pressure. Final technical report, April 1, 1990--March 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1993-06-21

    Experiments have been developed for measuring the rates of chemical reactions liquids and in supercritical Co{sub 2}. A pulsed (Q-switch) Nd:YAG laser at 355 nm was the pump beam for laser flash photolysis studies of molybdenum and tungsten hexacarbonyls undergoing ligand displacement reactions by bidentate chelating agents such as 2,2{prime}-bipyridine in toluene. Experiments were carried out at 0.1 to 150 MPa. In the case of molybdenum complexes, the reaction mechanism for thermal ring closure is found from activation volumes to change from associative interchange to dissociative interchange as substituents on the 2,2{prime}-bipyridine ligands become bulkier. In a similar study of more rigid, substituted phenanthroline bidentate ligands it was found that substituent bulkiness had little effect on the thermal ring closure mechanism. Similar high pressure flash photolysis experiments with tungsten hexacarbonyl have also been completed. The concentration dependence of the fluorescence and nonradiative decay quantum yields for cresyl violet in several solvent have been reported as well as stability constants for the complexation of lithium ion by four different crown ethers dissolved in a room temperature molten salt.

  3. Thermal regime of self-heated hollow cathode in a low-pressure high-current pulsed-periodic discharge

    Science.gov (United States)

    Gavrilov, N. V.; Emlin, D. R.

    2017-11-01

    We have studied the thermal regime of a self-heated hollow cathode in combined low-current (1-5 A) dc discharge and high-current (up to 100 A) pulsed-periodic discharge and the influence of the pulsed parameters on the current-voltage characteristic of the high-current discharge. It has been shown that, after the application of a voltage pulse (200-500 V), the discharge current attains its peak value and is stabilized over a time of 100 μs. The discharge voltage in the quasi-stationary discharge stage exceeds the continuous discharge voltage at the same current by many times and depends on the mean value of the current in the discharge gap. The interpretation of the form of the I-V characteristics of the pulsed discharge is based on the dynamics of heating and cooling of the cathode surface layer and on the variations in the integral temperature of the cathode.

  4. Patient Blood Pressure and Pulse Rate Monitoring With an Alert ...

    African Journals Online (AJOL)

    Blood pressure and pulse rate are two of the vital signs of humans and it is imperative that the chronically ill and the elderly patients need to have their blood pressure and pulse rate checked from time to time. This paper describes the use of the Omron 790it blood pressure monitor to check the blood pressure and the pulse ...

  5. Pulsed laser kinetic studies of liquids under high pressure. Progress report, November 29, 1990--November 25, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1991-11-25

    A high pressure apparatus constructed for measuring the rates of reactions in liquids under pressures ranging from 1 atm to 2000 atm has been used to measure the complexation kinetics of molybdenum hexacarbonyl reacting with 2,2-bipyridine, 4,4{prime}-dimethyl-2-2{prime}-bipyridine and 4,4{prime}-diphenyl-2-2{prime} bipyridine in toluene. Pentacarbonyl reaction intermediates are created by a 10 nsec flash of frequency tripled Nd:YAG laser light. Measured activation volumes for chelate ligand ring closure indicate a change in mechanism from associative interchange to dissociative interchange as steric hindrance increases. A similar high pressure kinetics study of molybdenum carbonyl complexation by several substituted phenanthrolines is now well advanced that indicates that with the more rigid phenanthroline ligands steric effects from bulky substituents have less effect on the ring closure mechanism than in the case of the bipyridine ligands. An experimental concentration dependence of the fluorescence quantum yield of cresyl violet has been harmonized with previously published contradictory reports. Fluorescence of cresyl violet in various solvents and in micellar systems has also been systematically explored.

  6. 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.

  7. Fast intraslab fluid-flow events linked to pulses of high pore fluid pressure at the subducted plate interface

    Science.gov (United States)

    Taetz, Stephan; John, Timm; Bröcker, Michael; Spandler, Carl; Stracke, Andreas

    2018-01-01

    A better understanding of the subduction zone fluid cycle and its chemical-mechanical feedback requires in-depth knowledge about how fluids flow within and out of descending slabs. Relicts of fluid-flow systems in exhumed rocks of fossil subduction zones allow for identification of the general relationships between dehydration reactions, fluid pathway formation, the dimensions and timescales of distinct fluid flow events; all of which are required for quantitative models for fluid-induced subduction zone processes. Two types of garnet-quartz-phengite veins can be distinguished in an eclogite-facies mélange block from the Pouébo Eclogite Mélange, New Caledonia. These veins record synmetamorphic internal fluid release by mineral breakdown reactions (type I veins), and infiltration of an external fluid (type II veins) with the associated formation of a reaction selvage. The dehydration and fluid migration documented by the type I veins likely occurred on a timescale of 105-106 years, based on average subduction rates and metamorphic conditions required for mineral dehydration and fluid flow. The timeframe of fluid-rock interaction between the external fluid and the wall-rock of the type II veins is quantified using a continuous bulk-rock Li-diffusion profile perpendicular to a vein and its metasomatic selvage. Differences in Li concentration between the internal and external fluid reservoirs resulted in a distinct diffusion profile (decreasing Li concentration and increasing δ7 Li) as the reaction front propagated into the host rock. Li-chronometric constraints indicate that the timescales of fluid-rock interaction associated with type II vein formation are on the order of 1 to 4 months (0.150-0.08+0.14 years). The short-lived, pulse-like character of this process is consistent with the notion that fluid flow caused by oceanic crust dehydration at the blueschist-to-eclogite transition contributes to or even dominates episodic pore fluid pressure increases at the

  8. Barrier discharges driven by sub-microsecond pulses at atmospheric pressure: Breakdown manipulation by pulse width

    Energy Technology Data Exchange (ETDEWEB)

    Hoder, Tomas; Hoeft, Hans; Kettlitz, Manfred; Weltmann, Klaus-Dieter; Brandenburg, Ronny [Leibniz Institute for Plasma Science and Technology, INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

    2012-07-15

    Barrier discharges at atmospheric pressure in nitrogen-oxygen mixture powered by high voltage pulses of widths between 10 {mu}s and 200 ns were investigated. The development of the microdischarges on rising and falling slopes was recorded by streak and intensified CCD cameras simultaneously. The breakdown on the falling slope strongly depends on the pulse width. As a result of pulse width variation the starting point of ignition changes and positive and negative streamers occur simultaneously in the falling slope. The observed effect is caused by the electric field rearrangement in the gap due to the different positive ion densities related to their gap crossing times.

  9. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... Print Page Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has high ... weight. How Will I Know if I Have High Blood Pressure? High blood pressure is a silent problem — you ...

  10. High speed, high current pulsed driver circuit

    Science.gov (United States)

    Carlen, Christopher R.

    2017-03-21

    Various technologies presented herein relate to driving a LED such that the LED emits short duration pulses of light. This is accomplished by driving the LED with short duration, high amplitude current pulses. When the LED is driven by short duration, high amplitude current pulses, the LED emits light at a greater amplitude compared to when the LED is driven by continuous wave current.

  11. High pressure neon arc lamp

    Science.gov (United States)

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  12. Relationship between Resting Heart Rate, Blood Pressure and Pulse Pressure in Adolescents

    Directory of Open Access Journals (Sweden)

    Diego Giulliano Destro Christofaro

    Full Text Available Abstract Background: High resting heart rate is considered an important factor for increasing mortality chance in adults. However, it remains unclear whether the observed associations would remain after adjustment for confounders in adolescents. Objectives: To analyze the relationship between resting heart rate, blood pressure and pulse pressure in adolescents of both sexes. Methods: A cross-sectional study with 1231 adolescents (716 girls and 515 boys aged 14-17 years. Heart rate, blood pressure and pulse pressure were evaluated using an oscillometric blood pressure device, validated for this population. Weight and height were measured with an electronic scale and a stadiometer, respectively, and waist circumference with a non-elastic tape. Multivariate analysis using linear regression investigated the relationship between resting heart rate and blood pressure and pulse pressure in boys and girls, controlling for general and abdominal obesity. Results: Higher resting heart rate values were observed in girls (80.1 ± 11.0 beats/min compared to boys (75.9 ± 12.7 beats/min (p ≤ 0.001. Resting heart rate was associated with systolic blood pressure in boys (Beta = 0.15 [0.04; 0.26] and girls (Beta = 0.24 [0.16; 0.33], with diastolic blood pressure in boys (Beta = 0.50 [0.37; 0.64] and girls (Beta = 0.41 [0.30; 0.53], and with pulse pressure in boys (Beta = -0.16 [-0.27; -0.04]. Conclusions: This study demonstrated a relationship between elevated resting heart rate and increased systolic and diastolic blood pressure in both sexes and pulse pressure in boys even after controlling for potential confounders, such as general and abdominal obesity.

  13. Structure and magnetic properties of ZnO films doped with Co, Ni or Mn synthesized by pulsed laser deposition under low and high oxygen partial pressures

    Energy Technology Data Exchange (ETDEWEB)

    Pivin, J.C. [CSNSM, Bat. 108, 91405 Orsay Campus (France)], E-mail: pivin@csnsm.in2p3.fr; Socol, G.; Mihailescu, I. [National Institute for Lasers, Plasma and Radiation Physics Lasers Department, Laser-Surface-Plasma Interactions Laboratory, PO Box MG-54, RO-77125, Bucharest-Magurele (Romania); Berthet, P. [LPCES-ICMMO, UMR8182-CNRS, Bat.410, Universite Paris Sud, 91405 Orsay Cedex (France); Singh, F. [CSNSM, Bat. 108, 91405 Orsay Campus (France); Inter University Accelerator Centre, Aruna Asaf Ali Marg, Post Box 10502, New Delhi, 110067 (India); Patel, M.K. [CSNSM, Bat. 108, 91405 Orsay Campus (France); High Pressure Physics Division, Bhabha Atomic Research Center, Purnima, Trombay, Mumbai 400 085 (India); Vincent, L. [CSNSM, Bat. 108, 91405 Orsay Campus (France)

    2008-11-28

    Zn{sub 1-} {sub x}M{sub x}O (M = Co, Ni, Mn) films with different concentrations of transition metal (10-30%) were synthesized by pulsed laser deposition. The substrates were heated at 400 deg. C and the depositions were performed either under secondary vacuum or under an oxygen pressure of 30 Pa. The occurrence of ion channeling in the films during Rutherford Backscattering Analysis, together with X-ray diffraction, optical absorption and transmission electron microscopy, clearly show that the M atoms are in solid solution on Zn sites. Magnetic properties were investigated by means of magnetometry at 5 and 300 K and Electron Spin Resonance. The Zn{sub 1-x}Co{sub x}O and Zn{sub 1-x}Ni{sub x}O films deposited under low O{sub 2} pressure exhibit both a ferromagnetic and a paramagnetic response up to 300 K, while films deposited under high O{sub 2} pressure and Zn{sub 1-x}Mn{sub x}O films are paramagnetic. Broad spin resonance peaks are recorded at room temperature, from ferromagnetic films only. The nearly isotropic magnetic response of these films, which is observed in ESR when varying the field orientation with respect to the surface, seems to indicate that the crystalline anisotropy oppose the shape anisotropy, because of the strong [001] texture of the films.

  14. 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.

  15. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... Situations Talking to Your Parents - or Other Adults Hypertension (High Blood Pressure) KidsHealth > For Teens > Hypertension (High Blood Pressure) Print ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

  16. Effect of pulse pressure on borehole stability during shear swirling flow vibration cementing

    Science.gov (United States)

    2017-01-01

    The shear swirling flow vibration cementing (SSFVC) technique rotates the downhole eccentric cascade by circulating cementing fluid. It makes the casing eccentrically revolve at high speed around the borehole axis. It produces strong agitation action to the annulus fluid, makes it in the state of shear turbulent flow, and results in the formation of pulse pressure which affects the surrounding rock stress. This study was focused on 1) the calculation of the pulse pressure in an annular turbulent flow field based on the finite volume method, and 2) the analysis of the effect of pulse pressure on borehole stability. On the upside, the pulse pressure is conducive to enhancing the liquidity of the annulus fluid, reducing the fluid gel strength, and preventing the formation of fluid from channeling. But greater pulse pressure may cause lost circulation and even formation fracturing. Therefore, in order to ensure smooth cementing during SSFVC, the effect of pulse pressure should be considered when cementing design. PMID:29145408

  17. Effect of pulse pressure on borehole stability during shear swirling flow vibration cementing.

    Directory of Open Access Journals (Sweden)

    Zhihua Cui

    Full Text Available The shear swirling flow vibration cementing (SSFVC technique rotates the downhole eccentric cascade by circulating cementing fluid. It makes the casing eccentrically revolve at high speed around the borehole axis. It produces strong agitation action to the annulus fluid, makes it in the state of shear turbulent flow, and results in the formation of pulse pressure which affects the surrounding rock stress. This study was focused on 1 the calculation of the pulse pressure in an annular turbulent flow field based on the finite volume method, and 2 the analysis of the effect of pulse pressure on borehole stability. On the upside, the pulse pressure is conducive to enhancing the liquidity of the annulus fluid, reducing the fluid gel strength, and preventing the formation of fluid from channeling. But greater pulse pressure may cause lost circulation and even formation fracturing. Therefore, in order to ensure smooth cementing during SSFVC, the effect of pulse pressure should be considered when cementing design.

  18. Pulsed laser kinetic studies of liquids under high pressure. Progress report, November 25, 1991--September 18, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Eyring, E.M.

    1992-09-22

    A laser flash photolysis kinetic study of 2,2{prime}-bipyridine bidentate chelating ligands with one claw in the first coordination sphere of a molybdenum carbonyl complex has been completed at pressures up to 150 MPa. The reaction mechanism for thermal ring closure is found from activation volumes to change from associative interchange to dissociative interchange as substituents on the 2,2{prime}-bipyridine ligands become bulkier. In a similar study of more rigid, substituted phenanthroline bidentate ligands it was found that substituent bulkiness had little effect on the thermal ring closure mechanism. Stability constants for lithium ion complexes with crown ethers in a room temperature molten salt, fluorescence quantum yields for cresyl violet and several other dyes in solution, and the oxidation of alcohols by OsO{sub 4} have also been investigated.

  19. Extracting oscillometric pulses from the cuff pressure: does it affect the pressures determined by oscillometric blood pressure monitors?

    Science.gov (United States)

    Amoore, John N

    2006-10-01

    Oscillometric noninvasive blood pressure measurement devices determine the pressures by analysing the relationship between the pressure in an occluding cuff and low-amplitude pressure pulses (oscillometric pulses) induced in the cuff by the arterial pressure wave. This paper examines the effects on the pulses and oscillometric pulse amplitude envelope of the filters that extract the pulses from the cuff pressure. The cuff pressure and oscillometric pulses extracted by the filter were recorded from a Critikon DINAMAP and a Datex Cardiocap, chosen because of accessibility of the filtered and unfiltered signals. The unfiltered oscillometric pulses were determined by subtracting the cuff pressure from a baseline constructed to represent either the Critikon's step deflation cuff pressure or the Datex's gradual pressure decrease. Waveforms were recorded from a noninvasive blood pressure test simulator and three volunteers. The filter alters the shape of oscillometric pulses causing a shift in the oscillometric pulse amplitude envelope drawn from the filtered pulses compared with that drawn from the unfiltered pulses in human subjects, but not the test simulator. The pulse shape distortion is dependent on the filter characteristics and the oscillometric pulse shape. Further work is required to explore whether this may help explain why simulators with artificial waveforms cannot validate noninvasive blood pressure monitors and why noninvasive blood pressure monitors may not be accurate in all patient groups.

  20. Short pulse mid-infrared amplifier for high average power

    CSIR Research Space (South Africa)

    Botha, LR

    2006-09-01

    Full Text Available High pressure CO 2 lasers are good candidates for amplifying picosecond mid infrared pulses. High pressure CO 2 lasers are notorious for being unreliable and difficult to operate. In this paper a high pressure CO 2 laser is presented based on well...

  1. Effect of interval training programme on pulse pressure in the ...

    African Journals Online (AJOL)

    pharmacological management of hypertension and may prevent cardiovascular event through the down regulation of PP in hypertension. Key words: Hypertension, Interval exercise, pulse pressure, cardiovascular risk factor, Blood pressure.

  2. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... other risk factors, like diabetes, you may need treatment. How does high blood pressure affect pregnant women? A few women will get high blood pressure when they are pregnant. When pregnant women get high blood pressure, it is called preeclampsia or toxemia. How do I control my high ...

  3. Preventing High Blood Pressure

    Science.gov (United States)

    ... Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN Preventing High Blood Pressure: Healthy Living Habits Recommend on Facebook Tweet Share ... meal and snack options can help you avoid high blood pressure and its complications. Be sure to eat plenty ...

  4. High blood pressure - children

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007696.htm High blood pressure - children To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  5. High blood pressure - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007329.htm High blood pressure - infants To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  6. High blood pressure medications

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007484.htm High blood pressure medicines To use the sharing features on this page, please enable JavaScript. Treating high blood pressure will help prevent problems such as heart disease, ...

  7. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... two types of high blood pressure. Primary (essential) hypertension For most adults, there's no identifiable cause of ... tends to develop gradually over many years. Secondary hypertension Some people have high blood pressure caused by ...

  8. Peak expiratory flow rate and Pulse Pressure values during the ...

    African Journals Online (AJOL)

    This study assessed the peak expiratory flow rate and pulse pressure during the luteal and menstruation phases of the menstrual cycle. The peak expiratory flow rate and pulse pressure were measured using the Wright's Peak Flow Meter and Mercury Sphygmomanometer respectively. The peak expiratory flow rate and ...

  9. Tunable high pressure lasers

    Science.gov (United States)

    Hess, R. V.

    1976-01-01

    Atmospheric transmission of high energy CO2 lasers is considerably improved by high pressure operation which, due to pressure broadening, permits tuning the laser lines off atmospheric absorption lines. Pronounced improvement is shown for horizontal transmission at altitudes above several kilometers and for vertical transmission through the entire atmosphere. Applications of tunable high pressure CO2 lasers to energy transmission and to remote sensing are discussed along with initial efforts in tuning high pressure CO2 lasers.

  10. High-pressure microbiology

    National Research Council Canada - National Science Library

    Michiels, Chris; Bartlett, Douglas Hoyt; Aertsen, Abram

    2008-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. High Hydrostatic Pressure Effects in the Biosphere: from Molecules to Microbiology * Filip Meersman and Karel Heremans . . . . . . . . . . . . 2. Effects...

  11. High Blood Pressure Facts

    Science.gov (United States)

    ... Stroke Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN High Blood Pressure Facts Recommend on Facebook Tweet Share Compartir On ... the facts about high blood pressure [PDF-255K] . High Blood Pressure in the United States About 75 million American ...

  12. High power ultrashort pulse lasers

    Energy Technology Data Exchange (ETDEWEB)

    Perry, M.D.

    1994-10-07

    Small scale terawatt and soon even petawatt (1000 terawatt) class laser systems are made possible by application of the chirped-pulse amplification technique to solid-state lasers combined with the availability of broad bandwidth materials. These lasers make possible a new class of high gradient accelerators based on the large electric fields associated with intense laser-plasma interactions or from the intense laser field directly. Here, we concentrate on the laser technology to produce these intense pulses. Application of the smallest of these systems to the production of high brightness electron sources is also introduced.

  13. High-speed pulse techniques

    CERN Document Server

    Coekin, J A

    1975-01-01

    High-Speed Pulse Techniques covers the many aspects of technique in digital electronics and encompass some of the more fundamental factors that apply to all digital systems. The book describes the nature of pulse signals and their deliberate or inadvertent processing in networks, transmission lines and transformers, and then examines the characteristics and transient performance of semiconductor devices and integrated circuits. Some of the problems associated with the assembly of these into viable systems operating at ultra high speed are also looked at. The book examines the transients and w

  14. High frequency pressure oscillator for microcryocoolers

    OpenAIRE

    Vanapalli, Srinivas; ter Brake, Hermanus J.M.; Jansen, Henricus V.; Zhao, Yiping; Holland, Herman J.; Burger, Johannes Faas; Elwenspoek, Michael Curt

    2008-01-01

    Microminiature pulse tube cryocoolers should operate at a frequency of an order higher than the conventional macro ones because the pulse tube cryocooler operating frequency scales inversely with the square of the pulse tube diameter. In this paper, the design and experiments of a high frequency pressure oscillator is presented with the aim to power a micropulse tube cryocooler operating between 300 and 80 K, delivering a cooling power of 10 mW. Piezoelectric actuators operate efficiently at ...

  15. Pulse pressure reduction and cardiovascular protection.

    Science.gov (United States)

    Laurent, Stéphane; Tropeano, Anne-Isabelle; Boutouyrie, Pierre

    2006-05-01

    Brachial pulse pressure (PP) is now a well-established cardiovascular risk factor. Central rather than peripheral PP should be measured to determine the 'true' haemodynamic effects of antihypertensive agents on target organs. Peripheral PP, measured at the brachial artery, does not reflect central PP (either carotid or ascending aorta), because their determinants are different and pathophysiological conditions and drugs may change central PP without changing peripheral PP. Central PP (i.e. carotid artery or ascending aorta) has shown an independent predictive value for all-cause mortality in patients with end-stage renal disease and in the hypertensive patients of the CAFE study. Antihypertensive treatment has repeatedly demonstrated its ability to prevent cardiovascular events. Whether the effect on cardiovascular events in clinical trials comparing two pharmacological classes or two therapeutic strategies is, at least partly, the result of differential effects on PP remains to be demonstrated. It is therefore of major importance to determine which therapeutic strategies may differentially lower central PP, and in turn reduce cardiovascular events. In clinical practice, lowering PP is often a difficult task, particularly in diabetic hypertensive individuals. In the PARADIS study, we aimed to determine, in a population of hypertensive patients with both type 2 diabetes and PP greater than 60 mmHg, which clinical characteristics predict the fall in PP on treatment and a reduction in cardiovascular events. The reinforcement of therapeutic measures, including a fixed low-dose perindopril/indapamide combination, made possible the effective lowering of PP and cardiovascular events in type 2 diabetic hypertensive patients, under conditions of usual care by general practitioners and specialists.

  16. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood, which leads to secondary high blood pressure. Risk Factors Anyone can develop high blood pressure; however, ... history of high blood pressure can increase your risk for developing high blood pressure. Age Blood pressure ...

  17. Arterial hypertension and pulse pressure in school-age children

    Directory of Open Access Journals (Sweden)

    Yu. M. Nechytailo

    2017-08-01

    Full Text Available Childhood arterial hypertension (AH has become a global problem not only for pediatrics, but also for public health in general. Objective. The aim of this study was to determine the prevalence of arterial hypertension among school-age children and diagnostic value of pulse pressure. Materials and Methods. In total 848 children in 10–17 years of age (mean age – 13.9 ± 0.06 years, 45.4 % boys and 54.6 % girls from urban and rural areas of Chernivtsi region were examined in schools during screening for elevated blood pressure (BP. School-based ambulatory seated BP was measured by oscillometric automated recording devices with the age selection of cuffs. Elevated systolic (SAP or diastolic (DAP pressure was diagnosed in those children with indicators above the 95th percentile of age norms in accordance with the national normative values. In cases of elevated BP the measurements were verificated by aneroid device. Results. It has been established that the frequency of high blood pressure in the examined school students was 25.2 %, including 17.7 % of arterial hypertension (BP above 95 percentile and 7.5 % – pre-hypertension (90–95 percentile. The prevalence of hypertension varied with age subgroups and the highest level was in 16 years of age – 29.9 % with high blood pressure (21.9 % above 95 percentile and 8.0 % between the 90th and 95th percentiles. Increased SAP was combined with an increased DAP in 47.3 % of cases and in the study had a positive correlation with overweight (r = 0.27, p < 0.05 and negative with physical performance (r = -0.21, p < 0.05. The pulse pressure had significant correlations with SAP, AH and overweight and it could be used as additional diagnostic index of AH. Conclusions. The prevalence of elevated BP in our study is higher than in European countries and exceeds 20 % of the child population. The elevated BP in our children has positive correlation with overweight and the negative with physical performance. The

  18. Ventilator-induced pulse pressure variation in neonates

    NARCIS (Netherlands)

    Heskamp, L.; Lansdorp, B.; Hopman, J.; Lemson, J.; Boode, W.P. de

    2016-01-01

    During positive pressure ventilation, arterial pressure variations, like the pulse pressure variation (PPV), are observed in neonates. However, the frequency of the PPV does not always correspond with the respiratory rate. It is hypothesized that PPV is caused by cardiopulmonary interaction, but

  19. Earthquake Triggering by High Power Electric Pulses

    Science.gov (United States)

    Novikov, Victor; Konev, Yuri; Zeigarnik, Vladimir

    2010-05-01

    The study carried out by the Joint Institute for High Temperatures in cooperation with the Institute of Physics of the Earth and the Research Station in Bishkek of Russian Academy of Sciences in 1999-2008 showed a response of weak seismicity at field experiments with electric pulsed power systems, as well as acoustic emission of rock specimens under laboratory conditions on high-power electric current pulses applied to the rocks. It was suggested that the phenomenon discovered may be used in practice for partial release of tectonic stresses in the Earth crust for earthquake hazard mitigation. Nevertheless, the mechanism of the influence of man-made electromagnetic field on the regional seismicity is not clear yet. One of possible cause of the phenomenon may be pore fluid pressure increase in the rocks under stressed conditions due to Joule heat generation by electric current injected into the Earth crust. It is known that increase of pore fluid pressure in the fault zone over a critical pressure of about 0.05 MPa is sufficient to trigger an earthquake if the fault is near the critical state due to accumulated tectonic deformations. Detailed 3D-calculaton of electric current density in the Earth crust of the Northern Tien Shan provided by pulsed electric high-power system connected to grounded electric dipole showed that at the depth of earthquake epicenters (over 5 km) the electric current density is lower than 10-7 A/m2 that is not sufficient for increase of pressure in the fluid-saturated porous geological medium due to Joule heat generation, which may provide formation of cracks resulting in the fault propagation and release of tectonic stresses in the Earth crust. Nevertheless, under certain conditions, when electric current will be injected into the fault through the casing pipes of two deep wells with preliminary injection of conductive fluid into the fault, the current density may be high enough for significant increase of mechanic pressure in the porous two

  20. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Back To Health Topics / High Blood Pressure High Blood Pressure Also known as Hypertension Leer en español ... vessels (arteries) at higher than normal pressures. Measuring Blood Pressure Blood pressure is the force of blood ...

  1. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... To Health Topics / High Blood Pressure High Blood Pressure Also known as Hypertension See also Information for ... arteries) at higher than normal pressures. Measuring Blood Pressure Blood pressure is the force of blood pushing ...

  2. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Back To Health Topics / High Blood Pressure High Blood Pressure Also known as Hypertension See also Information ... vessels (arteries) at higher than normal pressures. Measuring Blood Pressure Blood pressure is the force of blood ...

  3. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Back To Health Topics / High Blood Pressure High Blood Pressure Also known as Hypertension See also Information for ... vessels (arteries) at higher than normal pressures. Measuring Blood Pressure Blood pressure is the force of blood pushing ...

  4. Patient Blood Pressure and Pulse Rate Monitoring With an Alert ...

    African Journals Online (AJOL)

    2012-12-01

    Dec 1, 2012 ... cuff around your arm and, at a single press of a button, your blood pressure, pulse rate and any cardiac arrhythmias (heart beat irregularities) are calculated. The monitor benefits from Omron's 'IntelliSense' technology [1]. This is a great feature which takes your blood pressure into account and inflates.

  5. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... those used to diagnose high blood pressure, prehypertension can progress to high blood pressure and should be ... pressure weakens and damages your blood vessels, which can lead to complications . Types of High Blood Pressure ...

  6. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... the development of high blood pressure later in life. Environmental Causes of High Blood Pressure Environmental causes ... Tend to get high blood pressure earlier in life. Often, on average, have higher blood pressure numbers. ...

  7. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... and large arteries, which can affect blood pressure. Genetic Causes of High Blood Pressure Much of the ... involved in high blood pressure has come from genetic studies. High blood pressure often runs in families. ...

  8. High-pressure microfluidics

    Science.gov (United States)

    Hjort, K.

    2015-03-01

    When using appropriate materials and microfabrication techniques, with the small dimensions the mechanical stability of microstructured devices allows for processes at high pressures without loss in safety. The largest area of applications has been demonstrated in green chemistry and bioprocesses, where extraction, synthesis and analyses often excel at high densities and high temperatures. This is accessible through high pressures. Capillary chemistry has been used since long but, just like in low-pressure applications, there are several potential advantages in using microfluidic platforms, e.g., planar isothermal set-ups, large local variations in geometries, dense form factors, small dead volumes and precisely positioned microstructures for control of reactions, catalysis, mixing and separation. Other potential applications are in, e.g., microhydraulics, exploration, gas driven vehicles, and high-pressure science. From a review of the state-of-art and frontiers of high pressure microfluidics, the focus will be on different solutions demonstrated for microfluidic handling at high pressures and challenges that remain.

  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. Ventilator?induced pulse pressure variation in neonates

    OpenAIRE

    Heskamp, L.; Lansdorp, B.; Hopman, J; Lemson, J.; Boode, W.P. de

    2016-01-01

    Abstract During positive pressure ventilation, arterial pressure variations, like the pulse pressure variation (PPV), are observed in neonates. However, the frequency of the PPV does not always correspond with the respiratory rate. It is hypothesized that PPV is caused by cardiopulmonary interaction, but that this mismatch is related to the low respiratory rate/heart rate ratio. Therefore, the goal of this study is to investigate the relation between PPV and ventilation in neonates. A prospec...

  11. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... complications. Preventing High Blood Pressure Onset Healthy lifestyle habits can help prevent high blood pressure from developing. It is important to check your blood pressure regularly. Children should have their blood pressure checked starting at ...

  12. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... can help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother ... View all news on High Blood Pressure RELATED EVENT The Role of Microbiota in Blood Pressure Regulation ...

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure and should be taken seriously. Over time, consistently high blood pressure weakens and damages your ... Blood Pressure When blood pressure stays high over time, it can damage the body and cause complications. ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Card can help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for ... control your blood pressure before and during the pregnancy. Some women develop high blood pressure during pregnancy. ...

  15. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... or its complications. Preventing High Blood Pressure Onset Healthy lifestyle habits can help prevent high blood pressure from developing. It is important to check your blood pressure regularly. Children should have their blood pressure checked starting at ...

  16. Superconductivity under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, K.; Shimizu, K.; Takeda, K.; Tateiwa, N.; Muramatsu, T.; Ishizuka, M.; Kobayashi, T.C

    2003-05-01

    In part 1, we review techniques developed in our laboratory for producing the complex extreme condition of very low temperature and ultra-high pressure and those for measuring electrical resistance and magnetization of the sample confined in the extremely small space of the used pressure cell. In part 2, we review our experimental results in search for pressure-induced superconductivity, which have been obtained by the use of developed techniques. Typical examples are shown in the case of simple inorganic and organic molecular crystals, ionic crystals, and magnetic metals.

  17. High pressure induced superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, K.; Shimizu, K

    2003-10-15

    We have developed complex extreme condition of very low temperature down to 30 mK and ultra high pressure exceeding 200 GPa by assembling compact diamond anvil cell (DAC) on a powerful {sup 3}He/{sup 4}He dilution refrigerator. We have also developed measuring techniques of electrical resistance, magnetization and optical measurement for the sample confined in the sample space of the DAC. Using the newly developed apparatus and techniques, we have searched for superconductivity in various materials under pressure. In this paper, we will shortly review our newly developed experimental apparatus and techniques and discuss a few examples of pressure induced superconductivity which were observed recently.

  18. 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.

  19. Diamond-like carbon film preparation using a high-repetition nanosecond pulsed glow discharge plasma at gas pressure of 1 kPa generated by a SiC-MOSFET inverter power supply

    Science.gov (United States)

    Kikuchi, Yusuke; Ogura, Masataka; Maegawa, Takuya; Otsubo, Akira; Nishimura, Yoshimi; Nagata, Masayoshi; Yatsuzuka, Mitsuyasu

    2017-10-01

    A high-repetition nanosecond pulsed glow discharge plasma at a gas pressure of 1 kPa was generated using a SiC-MOSFET inverter power supply for diamond-like carbon (DLC) film preparation. At a high repetition frequency above 50 kHz, the period of the nanosecond voltage pulse became shorter than the decay time of the afterglow plasma, and many ions and radicals remained in the gap space. The deposition rate was 0.1 µm/min, which was 5 times higher than that of a conventional plasma CVD process. An increase in hardness to 13 GPa and a decrease in hydrogen content in the DLC film were confirmed by increasing the repetition frequency to 200 kHz.

  20. High Blood Pressure Fact Sheet

    Science.gov (United States)

    ... High Blood Pressure Salt Cholesterol Million Hearts® WISEWOMAN High Blood Pressure Fact Sheet Language: English (US) Español (Spanish) Recommend ... time. High blood pressure is also called hypertension. High Blood Pressure in the United States Having high blood pressure ...

  1. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... pressures. Measuring Blood Pressure Blood pressure is the force of blood pushing against the walls of the ... blood pressure, sometimes called hypertension, happens when this force is too high. Health care workers check blood ...

  2. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... harder and leading to high blood pressure. Medicines Prescription medicines such as asthma or hormone therapies, including ... aldosterone system leading to high blood pressure. Other Medical Causes of High Blood Pressure Other medical causes ...

  3. High frequency pressure oscillator for microcryocoolers

    Science.gov (United States)

    Vanapalli, S.; ter Brake, H. J. M.; Jansen, H. V.; Zhao, Y.; Holland, H. J.; Burger, J. F.; Elwenspoek, M. C.

    2008-04-01

    Microminiature pulse tube cryocoolers should operate at a frequency of an order higher than the conventional macro ones because the pulse tube cryocooler operating frequency scales inversely with the square of the pulse tube diameter. In this paper, the design and experiments of a high frequency pressure oscillator is presented with the aim to power a micropulse tube cryocooler operating between 300 and 80K, delivering a cooling power of 10mW. Piezoelectric actuators operate efficiently at high frequencies and have high power density making them good candidates as drivers for high frequency pressure oscillator. The pressure oscillator described in this work consists of a membrane driven by a piezoelectric actuator. A pressure ratio of about 1.11 was achieved with a filling pressure of 2.5MPa and compression volume of about 22.6mm3 when operating the actuator with a peak-to-peak sinusoidal voltage of 100V at a frequency of 1kHz. The electrical power input was 2.73W. The high pressure ratio and low electrical input power at high frequencies would herald development of microminiature cryocoolers.

  4. High Pressure Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  5. Blood pressure and pulse rate changes associated with cervical ...

    African Journals Online (AJOL)

    Background: This study was carried out at the Physiotherapy unit of the University of Maiduguri Teaching Hospital, to observe the effects of continuous cervical traction for 10 minutes on arterial blood pressure and pulse rate. Methods: Forty healthy subjects free of any cardiovascular complications, participated in the study.

  6. Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse ...

    African Journals Online (AJOL)

    Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse Rate Following Ingestion of Increased Coffee Concentrations in Healthy Male Adults. ... It further indicates that, mild doses of coffee confer benefits on airflow in the lungs. While higher doses are also beneficial in improving airflow in the airway, such doses ...

  7. Changes in Peak Expiratory Flow Rate, Blood Pressure and Pulse ...

    African Journals Online (AJOL)

    We studied the effect of different concentrations of coffee on peak expiratory flow rate (PEFR), blood pressure and pulse rate in an attempt to determine some physiological effects of coffee intake. 18 apparently healthy adult males, age range 20 to 30 years, were recruited for the study over a three day period. Varying ...

  8. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... outlines and defines high blood pressure severity levels. Stages of High Blood Pressure in Adults Stages Systolic (top number) Diastolic (bottom number) Prehypertension 120– ...

  9. Aspirated High Pressure Compressor

    Science.gov (United States)

    2006-08-01

    suggested by the General Electric Company based on an advanced military engine concept intended for high speed flight. The resultant high flight...section, consisting of the two rotors, each on an computed points. The peak pressure ratio is 3.08 and the peak independent, electric motor-driven...instrumentation along Moto . .. ,oto2 with the test error analysis were given by Onnee [14). SFlywheel 2 BLOWDOWN OPERATION T--’..Exit-t-rottle

  10. Acoustic pressure measurement of pulsed ultrasound using acousto-optic diffraction

    Science.gov (United States)

    Jia, Lecheng; Chen, Shili; Xue, Bin; Wu, Hanzhong; Zhang, Kai; Yang, Xiaoxia; Zeng, Zhoumo

    2018-01-01

    Compared with continuous ultrasound wave, pulsed ultrasound has been widely used in ultrasound imaging. The aim of this work is to show the applicability of acousto-optic diffraction on pulsed ultrasound transducer. In this paper, acoustic pressure of two ultrasound transducers is measured based on Raman-Nath diffraction. The frequencies of transducers are 5MHz and 10MHz. The pulse-echo method and simulation data are used to evaluate the results. The results show that the proposed method is capable to measure the absolute sound pressure. We get a sectional view of acoustic pressure using a displacement platform as an auxiliary. Compared with the traditional sound pressure measurement methods, the proposed method is non-invasive with high sensitivity and spatial resolution.

  11. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... page from the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers ... are consistently 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy ...

  12. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure. Primary High Blood Pressure Primary, or essential, high blood pressure is the most common type ... has no known cause, it might be called essential hypertension, primary hypertension, or idiopathic (id-ee-o- ...

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... from the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose ... consistently 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... increase your risk for developing high blood pressure. Age Blood pressure tends to rise with age. About 65 percent of Americans age 60 or older have high blood pressure. However, ...

  15. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Home / < Back To Health Topics / High Blood Pressure High Blood Pressure Also known as Hypertension Leer en español See ... defines high blood pressure severity levels. Stages of High Blood Pressure in Adults Stages Systolic (top number) Diastolic (bottom ...

  16. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Home / < Back To Health Topics / High Blood Pressure High Blood Pressure Also known as Hypertension See also Information for ... defines high blood pressure severity levels. Stages of High Blood Pressure in Adults Stages Systolic (top number) Diastolic (bottom ...

  17. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... are two main types of high blood pressure: primary and secondary high blood pressure. Primary High Blood Pressure Primary, ... plan based on whether you were diagnosed with primary or secondary high blood pressure and if there is a ...

  18. High-Altitude Electromagnetic Pulse (HEMP) Testing

    Science.gov (United States)

    2015-07-09

    Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Test Operations Procedure (TOP) 01-2-620A High-Altitude Electromagnetic Pulse ( HEMP ...planning and execution of testing Army/DOD equipment to determine the effects of Horizontal Component High Altitude Electromagnetic Pulse ( HEMP ...5 2.3 HEMP Pre/Post Test Illuminations ..................................................... 7 3. REQUIRED TEST

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... increased blood volumes and high blood pressure. Sympathetic Nervous System Activity The sympathetic nervous system has important functions in blood pressure regulation, including ...

  20. Diagnosis of High Blood Pressure

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    Full Text Available ... High Blood Pressure Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living ... Confirming High Blood Pressure A blood pressure test is easy and painless and can be done in ...

  1. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure: primary and secondary high blood pressure. Primary High Blood Pressure Primary, or essential, high blood pressure is the most ... known cause, it might be called essential hypertension, primary hypertension, or idiopathic (id-ee-o-PATH-ick) ...

  2. Diagnosis of High Blood Pressure

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    Full Text Available ... may stiffen small and large arteries, which can affect blood pressure. Genetic Causes of High Blood Pressure Much of the understanding of the body systems involved in high blood pressure has come from genetic studies. High blood pressure often runs in families. Years ...

  3. Diagnosis of High Blood Pressure

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    Full Text Available ... pressure and maintain normal blood pressure readings. Healthy Eating To help treat high blood pressure, health care ... more about the DASH eating plan. Heart-Healthy Eating Your health care provider also may recommend heart- ...

  4. Diagnosis of High Blood Pressure

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    Full Text Available ... can help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother ... With DASH My Blood Pressure Wallet Card Other Resources Cigarette and Tobacco Facts (National Institute ... OIG USA.gov

  5. Diagnosis of High Blood Pressure

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    Full Text Available ... providers diagnose high blood pressure when blood pressure readings are consistently 140/90 mmHg or above. Confirming ... minutes before the test. To track blood pressure readings over a period of time, the health care ...

  6. Diagnosis of High Blood Pressure

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    Full Text Available ... Nervous System Activity The sympathetic nervous system has important functions in blood pressure regulation, including heart rate, ... prevent high blood pressure from developing. It is important to check your blood pressure regularly. Children should ...

  7. Diagnosis of High Blood Pressure

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    Full Text Available ... blood pressure, he or she can order additional tests to determine if your blood pressure is due to other conditions or medicines or if you have primary high blood pressure. ...

  8. Diagnosis of High Blood Pressure

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    Full Text Available ... of your blood pressure, he or she can order additional tests to determine if your blood pressure ... health and can lower high blood pressure. Stress management techniques include: Being physically active Listening to music ...

  9. Pressure Dome for High-Pressure Electrolyzer

    Science.gov (United States)

    Norman, Timothy; Schmitt, Edwin

    2012-01-01

    A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom

  10. 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.

  11. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... control high blood pressure; lifestyle changes such as weight loss can be highly effective in treating high blood ... your risk for health problems. Greater amounts of weight loss can improve blood pressure readings, lower LDL cholesterol , ...

  12. 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.

  13. High Voltage Nanosecond Pulse Generator.

    Science.gov (United States)

    1978-11-01

    pulse to a laser load was desiqned , built , and tested . —- -~~~-~~~~----j ‘~ ~~ _)— ~ --. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ CoIx ~r 1 I

  14. Diagnosis of High Blood Pressure

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    Full Text Available ... care provider may need to change or add medicines to your treatment plan over time. NHLBI’s My Blood Pressure Wallet Card can help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother and baby. High blood pressure can ...

  15. Diagnosis of High Blood Pressure

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    Full Text Available ... mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless and can be done ... high blood pressure. Using the results of your blood pressure test, your health care provider will diagnose prehypertension or ...

  16. Methods for High Power EM Pulse Measurement

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2006-12-01

    Full Text Available There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday's induction law allows the measurement of generated current. For the same purpose the magneto-optic method can be utilized, with its advantages. For measurement of output microwave pulse of the generator the calorimetric method was designed and realized.

  17. Relationship between Resting Heart Rate, Blood Pressure and Pulse Pressure in Adolescents.

    Science.gov (United States)

    Christofaro, Diego Giulliano Destro; Casonatto, Juliano; Vanderlei, Luiz Carlos Marques; Cucato, Gabriel Grizzo; Dias, Raphael Mendes Ritti

    2017-05-01

    High resting heart rate is considered an important factor for increasing mortality chance in adults. However, it remains unclear whether the observed associations would remain after adjustment for confounders in adolescents. To analyze the relationship between resting heart rate, blood pressure and pulse pressure in adolescents of both sexes. A cross-sectional study with 1231 adolescents (716 girls and 515 boys) aged 14-17 years. Heart rate, blood pressure and pulse pressure were evaluated using an oscillometric blood pressure device, validated for this population. Weight and height were measured with an electronic scale and a stadiometer, respectively, and waist circumference with a non-elastic tape. Multivariate analysis using linear regression investigated the relationship between resting heart rate and blood pressure and pulse pressure in boys and girls, controlling for general and abdominal obesity. Higher resting heart rate values were observed in girls (80.1 ± 11.0 beats/min) compared to boys (75.9 ± 12.7 beats/min) (p ≤ 0.001). Resting heart rate was associated with systolic blood pressure in boys (Beta = 0.15 [0.04; 0.26]) and girls (Beta = 0.24 [0.16; 0.33]), with diastolic blood pressure in boys (Beta = 0.50 [0.37; 0.64]) and girls (Beta = 0.41 [0.30; 0.53]), and with pulse pressure in boys (Beta = -0.16 [-0.27; -0.04]). This study demonstrated a relationship between elevated resting heart rate and increased systolic and diastolic blood pressure in both sexes and pulse pressure in boys even after controlling for potential confounders, such as general and abdominal obesity. A frequência cardíaca de repouso é considerada um importante fator de aumento de mortalidade em adultos. Entretanto, ainda é incerto se as associações observadas permanecem após ajuste para fatores de confusão em adolescentes. Analisar a relação entre frequência cardíaca de repouso, pressão arterial e pressão de pulso em adolescentes dos dois sexos. Estudo transversal

  18. High power UV and VUV pulsed excilamps

    Science.gov (United States)

    Tarasenko, V.; Erofeev, M.; Lomaev, M.; Rybka, D.

    2008-07-01

    Emission characteristics of a nanosecond discharge in inert gases and its halogenides without preionization of the gap from an auxiliary source have been investigated. A volume discharge, initiated by an avalanche electron beam (VDIAEB) was realized at pressures up to 12 atm. In xenon at pressure of 1.2 atm, the energy of spontaneous radiation in the full solid angle was sim 45 mJ/cm^3, and the FWHM of a radiation pulse was sim 110 ns. The spontaneous radiation power rise in xenon was observed at pressures up to 12 atm. Pulsed radiant exitance of inert gases halogenides excited by VDIAEB was sim 4.5 kW/cm^2 at efficiency up to 5.5 %.

  19. Lower blood pressure and smaller pulse pressure in sleeping pill users

    Science.gov (United States)

    Sasaki, Nobuo; Fujiwara, Saeko; Ozono, Ryoji; Yamashita, Hidehisa; Kihara, Yasuki

    2017-01-01

    Abstract This study aimed to investigate the association between sleeping pill use and hypertension or blood pressure (BP) via a cross-sectional analysis. A total of 11,225 subjects (5875 men and 5350 women) underwent health examinations. We compared the proportion of sleeping pill users among hypertension (n = 5099) and normotensive (n = 6126) participants. We analyzed participants with no intake of antihypertensive medication (n = 7788), comparing the proportions with high systolic BP (SBP) ≥140, high diastolic BP (DBP) ≥90, and high pulse pressure (PP) ≥50 mm Hg across 3 subgroups. These groups were classified according to the sleeping pill use [nonuse group (n = 6869); low-frequency-use group, defined as taking sleeping pills ≤2 days per week (n = 344); and high-frequency-use group, defined as taking sleeping pills ≥3 days per week (n = 575)]. In the multivariable-adjusted model, odds of sleeping pill use (odds ratio (OR), 1.14; P < .05) was significantly higher in the hypertensive group compared with the normotensive group. In participants with no intake of antihypertensive medication, odds of high SBP (OR, 0.65; P < .0005), high DBP (OR, 0.58; P < .005), and high PP (OR, 0.77; P < .01) were significantly lower in the high-frequency-use group compared with the nonuse group. Odds of high DBP (OR, 0.59; P < .05) was significantly lower in the low-frequency-use group. Sleeping pills were more frequently required in hypertensive participants than in the normotensive ones. Sleeping pill use may decrease BP and assist in the treatment of high BP in patients with sleep disturbances. PMID:29049222

  20. High frequency and pulse scattering physical acoustics

    CERN Document Server

    Pierce, Allan D

    1992-01-01

    High Frequency and Pulse Scattering investigates high frequency and pulse scattering, with emphasis on the phenomenon of echoes from objects. Geometrical and catastrophe optics methods in scattering are discussed, along with the scattering of sound pulses and the ringing of target resonances. Caustics and associated diffraction catastrophes are also examined.Comprised of two chapters, this volume begins with a detailed account of geometrically based approximation methods in scattering theory, focusing on waves transmitted through fluid and elastic scatterers and glory scattering; surface ray r

  1. High Blood Pressure (Hypertension) (For Parents)

    Science.gov (United States)

    ... Pregnancy Healthy Food Shopping Healthy Drinks for Kids High Blood Pressure (Hypertension) KidsHealth > For Parents > High Blood Pressure (Hypertension) ... How Is High Blood Pressure Treated? What Is High Blood Pressure? Blood pressure is the pressure of blood against ...

  2. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... of physical activity Drinking too much alcohol Stress Family History A family history of high blood pressure raises the risk ... for high blood pressure and may run in families. Genetic causes of this condition are why family ...

  3. Medications for High Blood Pressure

    Science.gov (United States)

    ... Consumers Home For Consumers Consumer Updates Medications for High Blood Pressure Share Tweet Linkedin Pin it More sharing options ... age and you cannot tell if you have high blood pressure by the way you feel, so have your ...

  4. High blood pressure and diet

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007483.htm High blood pressure and diet To use the sharing features on ... diet is a proven way to help control high blood pressure . These changes can also help you lose weight ...

  5. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... can cause high blood pressure. Renin-Angiotensin-Aldosterone System The renin-angiotensin-aldosterone system makes angiotensin and ... blood volumes and high blood pressure. Sympathetic Nervous System Activity The sympathetic nervous system has important functions ...

  6. Diagnosis of High Blood Pressure

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    Full Text Available ... renin-angiotensin-aldosterone pathways. However, these known genetic factors only account for 2 to 3 percent of ... which leads to secondary high blood pressure. Risk Factors Anyone can develop high blood pressure; however, age, ...

  7. Diagnosis of High Blood Pressure

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    Full Text Available ... Institute on Drug Abuse) High Blood Pressure (MedlinePlus) High Blood Pressure and Kidney Disease (National Institute of Diabetes and Digestive and Kidney Diseases) RELATED NEWS December ...

  8. Diagnosis of High Blood Pressure

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    Full Text Available ... habits. The combination of the medicines and the healthy lifestyle habits helps control and lower your high blood pressure. Some people develop “resistant” or uncontrolled high blood pressure. This ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... control high blood pressure. Possible future treatments under investigation include new combination medicines, vaccines, and interventions aimed ... researchers on June 10, 2016, to share current scientific k... View all events on High Blood Pressure ...

  10. Diagnosis of High Blood Pressure

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    Full Text Available ... 139 OR 80–89 High blood pressure Stage 1 140–159 OR 90–99 High blood pressure ... To help make lifelong lifestyle changes, try making one healthy lifestyle change at a time and add ...

  11. Diagnosis of High Blood Pressure

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    Full Text Available ... potassium Lack of physical activity Drinking too much alcohol Stress Family History A family history of high blood pressure raises the risk of developing prehypertension or high blood pressure. Some ...

  12. Diagnosis of High Blood Pressure

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    Full Text Available ... and High Blood Pressure Researchers continue to study how various changes in normal body functions cause high ... to an increase in blood pressure. Aldosterone controls how the kidneys balance fluid and salt levels. Increased ...

  13. Diagnosis of High Blood Pressure

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    Full Text Available ... Also known as Hypertension See also Information for Health Professionals What Is High blood pressure is a common ... Before age 55, men are more likely than women to develop high blood pressure. After age 55, ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... hormones in your blood, which leads to secondary high blood pressure. Risk Factors Anyone can develop high blood pressure; however, age, race or ethnicity, being overweight, gender, ...

  15. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Ethnicity High blood pressure is more common in African American adults than in Caucasian or Hispanic American adults. Compared with these ethnic groups, African Americans: Tend to get high blood pressure earlier in ...

  16. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... being overweight or obese, and medicines. Unhealthy Lifestyle Habits Unhealthy lifestyle habits can cause high blood pressure, ... than men to develop high blood pressure. Lifestyle Habits Unhealthy lifestyle habits can raise your risk for ...

  17. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Imbalances in this kidney function can expand blood volumes, which can cause high blood pressure. Renin-Angiotensin- ... change this kidney function, leading to increased blood volumes and high blood pressure. Sympathetic Nervous System Activity ...

  18. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... for 2 to 3 percent of all cases. Emerging research suggests that certain DNA changes during fetal ... blood, which leads to secondary high blood pressure. Risk Factors Anyone can develop high blood pressure; however, ...

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... of all cases. Emerging research suggests that certain DNA changes during fetal development also may cause the development of high blood pressure later in life. Environmental Causes of High Blood Pressure Environmental causes of ...

  20. 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...

  1. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Advisory Committees Jobs Contact Us FAQs Home » Health Information for the Public » Health Topics » High Blood Pressure » Diagnosis of High Blood Pressure Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical ...

  2. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... page from the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose high ... are consistently 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless ...

  3. 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.

  4. Wuhan pulsed high magnetic field center

    OpenAIRE

    Li, Liang; Peng, Tao; Ding, Honfa; Han, Xiaotao; Ding, Tonghai; Chen, Jin; Wang, Junfeng; Xie, Jianfeng; Wang, Shaoliang; Duan, Xianzhong; Wang, Cheng; Herlach, Fritz; Vanacken, Johan; Pan, Yuan

    2008-01-01

    Wuhan pulsed high magnetic field facility is under development. Magnets of bore sizes from 12 to 34 mm with the peak field in the range of 50 to 80 T have been designed. The pulsed power supplies consists of a 12 MJ, 25 kV capacitor bank and a 100 MVA/100 MJ flywheel pulse generator. A prototype 1 MJ, 25 kV capacitor bank is under construction. Five magnets wound with CuNb wire and copper wire reinforced internally with Zylon fiber composites and externally with stainless steel shells have be...

  5. Effect of respiration on Korotkoff sounds and oscillometric cuff pressure pulses during blood pressure measurement.

    Science.gov (United States)

    Zheng, Dingchang; Di Marco, Luigi Yuri; Murray, Alan

    2014-05-01

    Blood pressure (BP) measurement accuracy depends on consistent changes in Korotkoff sounds (KorS) for manual measurement and oscillometric pulses for automated measurement, yet little is known about the direct effect of respiration on these physiological signals. The aim of this research was to quantitatively assess the modulation effect of respiration on Korotkoff sounds and oscillometric pulses. Systolic and diastolic blood pressures were measured manually from 30 healthy subjects (age 41 ± 12 years). Three static cuff pressure conditions were studied for two respiratory rates. Cuff pressure [with oscillometric pulses (OscP)], ECG, chest motion respiration [respiration signal (Resp), from magnetometer] and Korotkoff sounds (KorS, from digital stethoscope) were recorded twice for 20 s. The physiological data were evenly resampled. Respiratory frequency was calculated from Resp (fR), OscP (fO) and KorS (fK) from peak spectral frequency. There was no statistically significant difference between fR and fO or fK. Respiratory modulation was observed in all subjects. OscP amplitude modulation changed significantly between the two respiratory rates (p oscillometric pulse and Korotkoff sound amplitudes from which BP is measured.

  6. 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...

  7. Diagnosis of High Blood Pressure

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    Full Text Available ... Blood Pressure Much of the understanding of the body systems involved in high blood pressure has come from ... happens because medicines can change the way your body controls fluid and salt ... system leading to high blood pressure. Other Medical Causes ...

  8. Diagnosis of High Blood Pressure

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    Full Text Available ... Card can help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother and ... before and during the pregnancy. Some women develop high blood pressure during pregnancy. When this happens, your health care provider will ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... other conditions or medicines or if you have primary high blood pressure. Health care providers can use this information to develop your ... blood pressure persists or is first diagnosed as primary high blood pressure, your ... your health care provider may change or update your treatment plan ...

  10. Diagnosis of High Blood Pressure

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    Full Text Available ... for the test: Don’t drink coffee or smoke cigarettes for 30 minutes prior to the test. Go ... DASH My Blood Pressure Wallet Card Other Resources Cigarette and Tobacco Facts (National Institute on Drug Abuse) High Blood Pressure (MedlinePlus) High Blood Pressure ...

  11. Diagnosis of High Blood Pressure

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    Full Text Available ... Diagnosis of High Blood Pressure For most patients, health care providers diagnose high blood pressure when blood pressure ... and painless and can be done in a health care provider’s office or clinic. To prepare for the ...

  12. Diagnosis of High Blood Pressure

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    Full Text Available ... above. Confirming High Blood Pressure A blood pressure test is easy and painless and can be done ... provider’s office or clinic. To prepare for the test: Don’t drink coffee or smoke cigarettes for ...

  13. Diagnosis of High Blood Pressure

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    Full Text Available ... too high. Health care workers check blood pressure readings the same way for children, teens, and adults. ... Complications Because diagnosis is based on blood pressure readings, this condition can go undetected for years, as ...

  14. Diagnosis of High Blood Pressure

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    Full Text Available ... severity levels. Stages of High Blood Pressure in Adults Stages Systolic (top number) Diastolic (bottom number) Prehypertension ... in the table are blood pressure guides for adults who do not have any short-term serious ...

  15. Diagnosis of High Blood Pressure

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    Full Text Available ... check blood pressure readings the same way for children, teens, and adults. They use a gauge, stethoscope ... prehypertension and high blood pressure is increasing for children and teens, possibly due to the rise in ...

  16. Diagnosis of High Blood Pressure

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    Full Text Available ... and to follow your prescribed treatment plan, which will include healthy lifestyle habit recommendations and possibly medicines. ... your blood pressure test, your health care provider will diagnose prehypertension or high blood pressure if: Your ...

  17. Diagnosis of High Blood Pressure

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    Full Text Available ... American adults. Compared with these ethnic groups, African Americans: Tend to get high blood pressure earlier in life. Often, on average, have higher blood pressure numbers. ...

  18. Diagnosis of High Blood Pressure

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    Full Text Available ... increase your risk for developing high blood pressure. Age Blood pressure tends to rise with age. About ... mother’s kidneys and other organs and can cause early birth and low birth weight. If you’re ...

  19. Diagnosis of High Blood Pressure

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    Full Text Available ... condition is leading to uncontrolled blood pressure. Health care providers treat resistant or uncontrolled high blood pressure with an intensive treatment plan that can include a different set ...

  20. Diagnosis of High Blood Pressure

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    Full Text Available ... risk for prehypertension and high blood pressure is increasing for children and teens, possibly due to the ... II is a hormone that narrows blood vessels, increasing blood pressure. ACE converts Angiotensin I to Angiotensin ...

  1. Diagnosis of High Blood Pressure

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    Full Text Available ... may stiffen small and large arteries, which can affect blood pressure. Genetic Causes of High Blood Pressure ... which plaque builds up in leg arteries and affects blood flow in the legs. When people have ...

  2. Diagnosis of High Blood Pressure

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    Full Text Available ... work harder and leading to high blood pressure. Medicines Prescription medicines such as asthma or hormone therapies, ... or peaceful Performing yoga or tai chi Meditating Medicines Blood pressure medicines work in different ways to ...

  3. Diagnosis of High Blood Pressure

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    Full Text Available ... Operations and Administration Advisory Committees Budget and Legislative Information Jobs and Working at the NHLBI Contact and ... Blood Pressure Also known as Hypertension See also Information for Health Professionals What Is High blood pressure ...

  4. Diagnosis of High Blood Pressure

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    Full Text Available ... or tai chi Meditating Medicines Blood pressure medicines work in different ways to stop or slow some of the body’s functions that cause high blood pressure. Medicines to lower ...

  5. Diagnosis of High Blood Pressure

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    Full Text Available ... can help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother ... babies have good outcomes. Participate in NHLBI Clinical Trials The National Heart, Lung, and Blood Institute (NHLBI) ...

  6. Diagnosis of High Blood Pressure

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    Full Text Available ... health and can lower high blood pressure. Stress management techniques include: Being physically active Listening to music ... With DASH My Blood Pressure Wallet Card Other Resources Cigarette and Tobacco Facts (National Institute on ... OIG USA.gov

  7. Diagnosis of High Blood Pressure

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    Full Text Available ... structure and function. Biology and High Blood Pressure Researchers continue to study how various changes in normal ... including heart rate, blood pressure, and breathing rate. Researchers are investigating whether imbalances in this system cause ...

  8. Diagnosis of High Blood Pressure

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    Full Text Available ... health and can lower high blood pressure. Stress management techniques include: Being physically active Listening to music ... Blood Pressure and Kidney Disease (National Institute of Diabetes and Digestive and Kidney Diseases) RELATED NEWS December ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... ask for your readings. Blood Pressure Severity and Type Your health care provider usually takes 2–3 ... any other location. Health care providers diagnose this type of high blood pressure by reviewing readings in ...

  10. High Blood Pressure in Pregnancy

    Science.gov (United States)

    ... of the baby. Controlling your blood pressure during pregnancy and getting regular prenatal care are important for ... your baby. Treatments for high blood pressure in pregnancy may include close monitoring of the baby, lifestyle ...

  11. Diagnosis of High Blood Pressure

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  12. Diagnosis of High Blood Pressure

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    Full Text Available ... weakens and damages your blood vessels, which can lead to complications . Types of High Blood Pressure There ... Angiotensin narrows or constricts blood vessels, which can lead to an increase in blood pressure. Aldosterone controls ...

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  16. Diagnosis of High Blood Pressure

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  17. Diagnosis of High Blood Pressure

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  19. On random pressure pulses in the turbine draft tube

    Science.gov (United States)

    Kuibin, P. A.; Shtork, S. I.; Skripkin, S. G.; Tsoy, M. A.

    2017-04-01

    The flow in the conical part of the hydroturbine draft tube undergoes various instabilities due to deceleration and flow swirling at off-design operation points. In particular, the precessing vortex rope develops at part-load regimes in the draft tube. This rope induces periodical low-frequency pressure oscillations in the draft tube. Interaction of rotational (asynchronous) mode of disturbances with the elbow can bring to strong oscillations in the whole hydrodynamical system. Recent researches on flow structure in the discharge cone in a regime of free runner had revealed that helical-like vortex rope can be unstable itself. Some coils of helix close to each other and reconnection appears with generation of a vortex ring. The vortex ring moves toward the draft tube wall and downstream. The present research is focused on interaction of vortex ring with wall and generation of pressure pulses.

  20. Plasma high-order-harmonic generation from ultraintense laser pulses

    Science.gov (United States)

    Tang, Suo; Kumar, Naveen; Keitel, Christoph H.

    2017-05-01

    Plasma high-order-harmonic generation from an extremely intense short-pulse laser is explored by including the effects of ion motion, electron-ion collisions, and radiation reaction force in the plasma dynamics. The laser radiation pressure induces plasma ion motion through the hole-boring effect, resulting in frequency shifting and widening of the harmonic spectra. The classical radiation reaction force slightly mitigates the frequency broadening caused by the ion motion. Based on the results and physical considerations, parameter maps highlighting the optimum regions for generating a single intense attosecond pulse and coherent XUV radiation are presented.

  1. Aging, vascular risk, and cognition: blood glucose, pulse pressure, and cognitive performance in healthy adults.

    Science.gov (United States)

    Dahle, Cheryl L; Jacobs, Bradley S; Raz, Naftali

    2009-03-01

    Advanced age is associated with decline in many areas of cognition as well as increased frequency of vascular disease. Well-described risk factors for vascular disease, such as diabetes and arterial hypertension, have been linked to cognitive deficits beyond those associated with aging. To examine whether vascular health indices such as fasting blood glucose levels and arterial pulse pressure can predict subtle deficits in age-sensitive abilities, the authors studied 104 healthy adults (ages 18 to 78) without diagnoses of diabetes or hypertension. Whereas results revealed a classic pattern of age-related differences in cognition, preprandial blood glucose level and pulse pressure independently and differentially affected cognitive performance. High-normal blood glucose levels were associated with decreased delayed associative memory, reduced accuracy of working memory processing among women, and slower working memory processing among men. Elevated pulse pressure was associated with slower perceptual-motor processing. Results suggest that blood glucose levels and pulse pressure may be sensitive indicators of cognitive status in healthy adults; however, longitudinal research is needed to determine whether such relatively mild elevations in this select group predict age-related cognitive declines.

  2. High pressure direct injection

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J. [Cummins Westport Inc., Vancouver, BC (Canada)

    2002-07-01

    A brief overview of Cummins Westport was provided, indicating that Westport originated in the 1980s through a research team at the University of British Columbia, and the hiring of the first employees began in 1996. The joint venture between Cummins and Westport was formed in March 2001. Cummins is the largest builder of commercial diesels in the world, and Westport is a small incubation technology company with emphasis on natural gas. The contribution of each company benefits the joint venture. Cummins brings traditional expertise in product and process development and distribution system, while Westport contributes new high pressure direct injection (HPDI) technology, funding and enthusiasm. The same base engine is kept and only the fuel system is changed. HPDI uses diesel cycle combustion and diesel pilot ignites natural gas. It allows for low emissions, high performance, high efficiency and economic payback. The pilot-ignited HPDI technology was explained, and its application to large class-8 trucks was discussed. The efficiency and performance of diesel engines is maintained by HPDI technology, there are 40 per cent reductions in nitrous oxide emissions, particulate matter emissions are reduced by 60 per cent, and carbon dioxide emissions are reduced by 20 per cent. A field demonstration was reviewed, and the major test at Norcal in San Francisco was discussed. The key success factors were found to be: formalized customer support plan, on-site technical support, parts availability, driver support and interaction, and training. Liquid natural gas fuel contamination was found to cause component wear. The emphasis has now been placed on three issues: injector life improvements, fuel debris and liquid natural gas pump/dome regulator life, and fuel economy improvements. The accomplishments for 2001 were identified, such as rapidly improving reliability, 17 HPDI trucks are upfit and in-service to name a few. The goals for 2002 include the placement of permanent fuel

  3. 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.

  4. Producing High Intense Attosecond Pulse Train by Interaction of Three-Color Pulse and Overdense Plasma

    Science.gov (United States)

    Salehi, M.; Mirzanejad, S.

    2017-05-01

    Amplifying the attosecond pulse by the chirp pulse amplification method is impossible. Furthermore, the intensity of attosecond pulse is low in the interaction of laser pulse and underdense plasma. This motivates us to propose using a multi-color pulse to produce the high intense attosecond pulse. In the present study, the relativistic interaction of a three-color linearly-polarized laser-pulse with highly overdense plasma is studied. We show that the combination of {{ω }}1, {{ω }}2 and {{ω }}3 frequencies decreases the instance full width at half maximum reflected attosecond pulse train from the overdense plasma surface. Moreover, we show that the three-color pulse increases the intensity of generated harmonics, which is explained by the relativistic oscillating mirror model. The obtained results demonstrate that if the three-color laser pulse interacts with overdense plasma, it will enhance two orders of magnitude of intensity of ultra short attosecond pulses in comparison with monochromatic pulse.

  5. Association of adiposity with pulse pressure amongst gujarati Indian adolescents.

    Science.gov (United States)

    Shaikh, Wasim A; Patel, Minal; Singh, Sk

    2010-07-01

    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 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. A significant positive correlationship was found between adiposity and PP in boys. However, no significant correlationship was found between adiposity and PP in girls. 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.

  6. 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.

  7. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure and maintain normal blood pressure readings. Healthy Eating To help treat high blood pressure, health care providers recommend that you limit sodium and salt intake, increase potassium, and eat foods that are heart healthy. Limiting Sodium and Salt ...

  8. Pulsing ULXs as highly magnetized neutron stars

    Science.gov (United States)

    Mushtukov, A.; Suleimanov, V.; Tsygankov, S.; Poutanen, J.

    2017-10-01

    A recent discovery of three pulsing ultraluminous X-ray sources (ULXs) demonstrates that a significant part of ULXs could be magnetized neutron stars with extremely high mass accretion rates. Theoreticians are thus faced with a significant challenge to invent a way for transforming a highly super-Eddington accretion rate into pulsing photon luminosity. We suggested a model of the two tall accretion columns above a strongly magnetized (B ˜ 10^{14} G) neutron star surface in the vicinity of the magnetic poles as a source of this radiation, and showed that their luminosity can be as high as 10^{40} erg s^{-1}. We present the basic ideas of the model as well as possible directions for improving the model to increase its maximum possible luminosity. The results of application of the model to the ULX M82 X-2 and to other pulsed ULXs are presented.

  9. A Method to Determine Diastolic Blood Pressure Based on Pressure Pulse Propagation in the Electronic Palpation Method

    Science.gov (United States)

    2001-10-25

    electronically palpated pulse. This particular patient seems to have arrhythmia, and, because of that, oscillometric blood pressure methods may give...of multiple oscillometric methods for blood pressure measurement in finger�, Proceedings of The First Joint BMES/EMBS Conference Serving Humanity...1 of 4 A METHOD TO DETERMINE DIASTOLIC BLOOD PRESSURE BASED ON PRESSURE PULSE PROPAGATION IN THE ELECTRONIC PALPATION METHOD H. S. S

  10. Diagnosis of High Blood Pressure

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    Full Text Available ... of Intramural Research Research Resources Research Meeting Summaries Technology Transfer ... » Health Information for the Public » Health Topics » High Blood Pressure » ...

  11. What Is High Blood Pressure?

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More What is High Blood Pressure? Updated:Oct 5,2017 First, let’s define high ... resources . This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  12. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... to cognitive changes. Signs and symptoms include memory loss, difficulty finding words, and losing focus during conversations. ... high blood pressure; lifestyle changes such as weight loss can be highly effective in treating high blood ...

  13. Diagnosis of High Blood Pressure

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    Full Text Available ... control high blood pressure; lifestyle changes such as weight loss can be highly effective in treating high blood ... If you’re overweight or obese, try to lose weight. A loss of just 3 to 5 percent ...

  14. 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.

  15. Vascular Stiffness and Increased Pulse Pressure in the Aging Cardiovascular System

    OpenAIRE

    Jochen Steppan; Viachaslau Barodka; Berkowitz, Dan E; Daniel Nyhan

    2011-01-01

    Aging leads to a multitude of changes in the cardiovascular system, including systolic hypertension, increased central vascular stiffness, and increased pulse pressure. In this paper we will review the effects of age-associated increased vascular stiffness on systolic blood pressure, pulse pressure, augmentation index, and cardiac workload. Additionally we will describe pulse wave velocity as a method to measure vascular stiffness and review the impact of increased vascular stiffness as an in...

  16. Highly Efficient Vector-Inversion Pulse Generators

    Science.gov (United States)

    Rose, Franklin

    2004-01-01

    Improved transmission-line pulse generators of the vector-inversion type are being developed as lightweight sources of pulsed high voltage for diverse applications, including spacecraft thrusters, portable x-ray imaging systems, impulse radar systems, and corona-discharge systems for sterilizing gases. In this development, more than the customary attention is paid to principles of operation and details of construction so as to the maximize the efficiency of the pulse-generation process while minimizing the sizes of components. An important element of this approach is segmenting a pulse generator in such a manner that the electric field in each segment is always below the threshold for electrical breakdown. One design of particular interest, a complete description of which was not available at the time of writing this article, involves two parallel-plate transmission lines that are wound on a mandrel, share a common conductor, and are switched in such a manner that the pulse generator is divided into a "fast" and a "slow" section. A major innovation in this design is the addition of ferrite to the "slow" section to reduce the size of the mandrel needed for a given efficiency.

  17. High Blood Pressure and Women

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More High Blood Pressure and Women Updated:Dec 14,2016 Pregnancy and ... Women . This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  18. Common High Blood Pressure Myths

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Common High Blood Pressure Myths Updated:Dec 8,2017 Knowing the facts ... health. This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... other conditions or medicines or if you have primary high blood pressure. Health care providers can use this information to develop your treatment plan. Some people have “white coat hypertension.” This happens when blood pressure readings are only high when taken in a health ...

  20. High Pressure Research on Materials

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 6. High Pressure Research on Materials - Production and Measurement of High Pressures in the Laboratory. P Ch Sahu N V Chandra Shekar. General Article Volume 12 Issue 6 June 2007 pp 10-23 ...

  1. Diagnosis of High Blood Pressure

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  3. Diagnosis of High Blood Pressure

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  4. Diagnosis of High Blood Pressure

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    Full Text Available ... Stroke Other Resources Many resources are available for support and to provide additional information on high blood pressure not found elsewhere in this Health Topic. NHLBI Resources Healthy Hearts, Healthy Homes: Keep the Beat: Control Your High Blood Pressure/ ...

  5. Diagnosis of High Blood Pressure

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    Full Text Available ... numbers are too high. Causes Changes, either from gene or the environment, in the body’s normal functions ... in families. Years of research have identified many genes and other mutations associated with high blood pressure, ...

  6. Diagnosis of High Blood Pressure

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  7. Diagnosis of High Blood Pressure

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  8. Diagnosis of High Blood Pressure

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    Full Text Available ... system activity , and blood vessel structure and function. Biology and High Blood Pressure Researchers continue to study ... balances, cause your blood vessels to constrict, or impact the renin-angiotensin-aldosterone system leading to high ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... numbers are too high. Causes Changes, either from genes or the environment, in the body’s normal functions ... in families. Years of research have identified many genes and other mutations associated with high blood pressure, ...

  10. Diagnosis of High Blood Pressure

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  11. Diagnosis of High Blood Pressure

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  14. Diagnosis of High Blood Pressure

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    Full Text Available ... estrogen, and over-the-counter medicines such as cold relief medicines may cause this form of high ... blood pressure stays high over time, it can damage the body and cause complications. Some common complications ...

  15. Diagnosis of High Blood Pressure

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    Full Text Available ... 120/80 mmHg. The following table outlines and defines high blood pressure severity levels. Stages of High ... American College of Cardiology (ACC), the guidelines now define hypertension as a systolic blood... View all news ...

  16. 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.

  17. 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.

  18. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... blood vessels, induction of a high fever, and strict low-sodium diets. Case studies suggested that each ... with scientific and medical communities to update hypertension management guidelines (JNC-8), including integrating them with updated ...

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... health and can lower high blood pressure. Stress management techniques include: Being physically active Listening to music or focusing on something calm or peaceful Performing yoga or tai chi Meditating Medicines Blood pressure medicines work in different ways to stop or slow some of the ...

  20. Diagnosis of High Blood Pressure

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    Full Text Available ... of Intramural Research Research Resources Research Meeting Summaries Technology Transfer Clinical Trials What Are Clinical Trials? Children & ... or at other locations that have blood pressure equipment and to keep a written ... at several medical appointments to diagnose high blood pressure. Using the ...

  1. High Pressure Research on Materials

    Indian Academy of Sciences (India)

    basic types of apparatus that are now being used throughout the world. He was awarded the Nobel Prize in Physics in 1946. The static high pressure generating devices can be divided into two categories: piston-cylinder and opposed anvil devices. These devices with their pressure capabilities are listed in Figure 4.

  2. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... pressure readings, lower LDL cholesterol , and increase HDL cholesterol . However, research shows that no matter your weight, it is important to control high blood pressure to maintain good health. A useful measure of overweight and obesity is body mass index (BMI). BMI measures your ...

  3. Diagnosis of High Blood Pressure

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    Full Text Available ... learn how to check your blood pressure at home. Your health care provider can help you learn how to do ... to lower the chance of complications. With such care, most women and babies have good ... Resources Healthy Hearts, Healthy Homes: Keep the Beat: Control Your High Blood Pressure/ ...

  4. Diagnosis of High Blood Pressure

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    Full Text Available ... NHLBI About NHLBI Home Mission and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees Budget ... health and can lower high blood pressure. Stress management techniques include: Being physically ... SPRINT trial played a key role in the evolution of the new blood pressure ...

  5. Diagnosis of High Blood Pressure

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    Full Text Available ... physical health and can lower high blood pressure. Stress management techniques include: Being physically active Listening to music or focusing on something calm or peaceful Performing yoga or tai chi Meditating Medicines Blood pressure medicines work in different ways to stop or slow some ...

  6. Diagnosis of High Blood Pressure

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    Full Text Available ... NHLBI About NHLBI Home Mission and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees Budget ... health and can lower high blood pressure. Stress management techniques include: Being physically ... pressure medicines work in different ways to stop or slow some of the ...

  7. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... or focusing on something calm or peaceful Performing yoga or tai chi Meditating Medicines Blood pressure medicines work in different ways to stop or slow some of the body’s functions that cause high blood pressure. Medicines to ...

  8. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Severity and Type Your health care provider usually takes 2–3 readings at several medical appointments to diagnose high blood pressure. Using the results of your blood pressure test, your health care provider will diagnose prehypertension or ...

  9. Pulse volume discharges in high pressure gases

    Science.gov (United States)

    Yamshchikov, V. A.

    2015-11-01

    New approach for suppression of plasma inhomogeneities and instabilities in the volume self-sustained discharge is offered. The physical model is offered and conditions of obtaining extremely homogeneous self-sustained discharge are defined (with full suppression of plasma inhomogeneity and instability). Results of calculations agree with experiments.

  10. High-pressure and pulsed electric field

    DEFF Research Database (Denmark)

    Olsen, Nina Veflen; Sonne, Anne-Mette

    2010-01-01

    New products and new processing techniques are continuously developed within the food industry. While food scientists may focus on the technical novelty and applaud the progress of science, consumers are often conservative and skeptical towards changes. As learned from earlier experiences with gene...

  11. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... high. Causes Changes, either from genes or the environment, in the body’s normal functions may cause high ... in life. Environmental Causes of High Blood Pressure Environmental ... to constrict, or impact the renin-angiotensin-aldosterone system leading to high ...

  12. Strain sensors for high field pulse magnets

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Christian [Los Alamos National Laboratory; Zheng, Yan [Los Alamos National Laboratory; Easton, Daniel [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory

    2009-01-01

    In this paper we present an investigation into several strain sensing technologies that are being considered to monitor mechanical deformation within the steel reinforcement shells used in high field pulsed magnets. Such systems generally operate at cryogenic temperatures to mitigate heating issues that are inherent in the coils of nondestructive, high field pulsed magnets. The objective of this preliminary study is to characterize the performance of various strain sensing technologies at liquid nitrogen temperatures (-196 C). Four sensor types are considered in this investigation: fiber Bragg gratings (FBG), resistive foil strain gauges (RFSG), piezoelectric polymers (PVDF), and piezoceramics (PZT). Three operational conditions are considered for each sensor: bond integrity, sensitivity as a function of temperature, and thermal cycling effects. Several experiments were conducted as part of this study, investigating adhesion with various substrate materials (stainless steel, aluminum, and carbon fiber), sensitivity to static (FBG and RFSG) and dynamic (RFSG, PVDF and PZT) load conditions, and sensor diagnostics using PZT sensors. This work has been conducted in collaboration with the National High Magnetic Field Laboratory (NHMFL), and the results of this study will be used to identify the set of sensing technologies that would be best suited for integration within high field pulsed magnets at the NHMFL facility.

  13. Generation And Measurement Of High Contrast Ultrashort Intense Laser Pulses

    CERN Document Server

    Konoplev, O A

    2000-01-01

    In this thesis, the generation and measurement of high contrast, intense, ultrashort pulses have been studied. Various factors affecting the contrast and pulse shape of ultrashort light pulses from a chirped pulse amplification (CPA) laser system are identified. The level of contrast resulting from influence of these factors is estimated. Methods for improving and controlling the pulse shape and increasing the contrast are discussed. Ultrahigh contrast, 1-ps pulses were generated from a CPA system with no temporal structure up to eleven orders of magnitude. This is eight orders of magnitude higher contrast than the original pulse. This contrast boost was achieved using two techniques. One is the optical pulse cleaning based on the nonlinear birefringence of the chirping fiber and applied to the pulses before amplification. The other is the fast saturable absorber. The fast saturable absorber was placed after amplification and compression of the pulse. The measurements of high-contrast, ultrashort pulse with h...

  14. Diagnosis of High Blood Pressure

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  16. Diagnosis of High Blood Pressure

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  17. High Blood Pressure and Pregnancy

    Science.gov (United States)

    Healthy Lifestyle Pregnancy week by week High blood pressure and pregnancy isn't necessarily a dangerous combination. Here's what you ... 2017 Original article: http://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20046098 . ...

  18. Diagnosis of High Blood Pressure

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  19. Diagnosis of High Blood Pressure

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    Full Text Available ... Obesity, Nutrition, and Physical Activity Population and Epidemiology Studies Women’s Health All Science A-Z Grants & Training ... Biology and High Blood Pressure Researchers continue to study how various changes in normal body functions cause ...

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  14. Diagnosis of High Blood Pressure

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  15. Diagnosis of High Blood Pressure

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    Full Text Available ... Nutrition, and Physical Activity Population and Epidemiology Studies Women’s Health All Science A-Z Grants & Training Grants ... Before age 55, men are more likely than women to develop high blood pressure. After age 55, ...

  17. High Field Pulse Magnets with New Materials

    Science.gov (United States)

    Li, L.; Lesch, B.; Cochran, V. G.; Eyssa, Y.; Tozer, S.; Mielke, C. H.; Rickel, D.; van Sciver, S. W.; Schneider-Muntau, H. J.

    2004-11-01

    High performance pulse magnets using the combination of CuNb conductor and Zylon fiber composite reinforcement with bore sizes of 24, 15 and 10 mm have been designed, manufactured and tested to destruction. The magnets successfully reached the peak fields of 64, 70 and 77.8 T respectively with no destruction. Failures occurred near the end flanges at the layer. The magnet design, manufacturing and testing, and the mode of the failure are described and analyzed.

  18. Electrokinetic high pressure hydraulic system

    Science.gov (United States)

    Paul, Phillip H.; Rakestraw, David J.

    2000-01-01

    A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

  19. Electrokinetic high pressure hydraulic system

    Science.gov (United States)

    Paul, Phillip H.; Rakestraw, David J.; Arnold, Don W.; Hencken, Kenneth R.; Schoeniger, Joseph S.; Neyer, David W.

    2001-01-01

    An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based systems. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (Microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

  20. 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

  1. [Pulse pressure and mean pressure: physiopathology and predictive value of coronary events and ictus].

    Science.gov (United States)

    Verdecchia, P

    2001-11-01

    Increased pulse pressure (PP) reflects an increased stiffness of aorta and other large elastic arteries. These arteries dilate by about 10% during systole and contract owing to elastic return during diastole. As a result, blood flow towards periphery becomes less pulsatile and more continuous. An increased stiffness of aorta and large elastic arteries due to progressively reduced elastic content with aging (atherosclerotic processes) leads to increased systolic blood pressure (BP), because of their reduced distension during systole, and decreased diastolic BP due to their reduced blood content at the beginning of diastole. Several epidemiological studies have shown that PP is the BP component which most closely predicts cardiovascular risk, particularly over 55 years of age. In particular, increased PP is an important predictor of coronary events, while increased mean BP is a more specific predictor of cerebrovascular events.

  2. High energy high rate pulsed power processing of materials by powder consolidation and by railgun deposition

    Science.gov (United States)

    Persad, C.; Marcus, H. L.; Weldon, W. F.

    1987-03-01

    This exploratory research program was initiated to investigate the potential of using pulse power sources for powder consolidation, deposition and other High Energy High Rate Processing. The characteristics of the High Energy High Rate (1MJ/s) powder consolidation using megampere current pulses from a Homopolar Generator, have been defined. Molybdenum Alloy TZM, A Nickel based metallic glass, Copper graphite composites, and P/M Aluminum Alloy X7091 have been investigated. The powder consolidation process produced high densification rates. Density values of 80% to 99% could be obtained with sub second high temperature exposure. Specific energy input and applied pressure were controlling process parameters. Time Temperature Transformation (TTT) concepts underpin a fundamental understanding of pulsed power processing. Deposition experiments were conducted using an exploding foil device (EFD) providing an armature feed to railgun mounted in a vacuum chamber. The material to be deposited - in plasma, gas, liquid or solid state - was accelerated electromagnetically in the railgun and deposited on a substrate.

  3. Intermolecular Interactions at high pressure

    DEFF Research Database (Denmark)

    Eikeland, Espen Zink

    2016-01-01

    In this project high-pressure single crystal X-ray diffraction has been combined with quantitative energy calculations to probe the energy landscape of three hydroquinone clathrates enclosing different guest molecules. The simplicity of the hydroquinone clathrate structures together with their st......In this project high-pressure single crystal X-ray diffraction has been combined with quantitative energy calculations to probe the energy landscape of three hydroquinone clathrates enclosing different guest molecules. The simplicity of the hydroquinone clathrate structures together....... High-pressure crystallography is the perfect method for studying intermolecular interactions, by forcing the molecules closer together. In all three studied hydroquinone clathrates, new pressure induced phase transitions have been discovered using a mixture of pentane and isopentane as the pressure...... transmitting medium. Through careful structural analysis combined with theoretical calculations, the structures of all the new high-pressure phases identified herein were determined. In the hydroquinone - methanol and hydroquinone - acetonitrile clathrate structures the phase transitions break the host...

  4. Starch Gelatinization Induced by High Hydrostatic Pressure

    National Research Council Canada - National Science Library

    Kazutaka YAMAMOTO

    2013-01-01

    .... Starch gelatinization can also be induced by high hydrostatic pressure. Requirements for pressure gelatinization may also differ depending on botanical origin of starch, pressure, water, and temperature...

  5. Pulsed high voltage discharge induce hematologic changes

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... The aim of this work to examine the effect of the gas-liquid hybrid discharge treatment system on some hematological ... liquid phase. The high energy plasma arc produces a pressure shock wave, electromagnetic radiations, .... through a 50 kilo-ohm resistor by a negative dc high-voltage power supply and ...

  6. A practical and reliable method of measuring blood pressure in the neonate by pulse oximetry.

    Science.gov (United States)

    Langbaum, M; Eyal, F G

    1994-10-01

    We investigated the reliability of the plethysmographic waveform of the pulse oximeter to measure systolic blood pressure in sick neonates. Fifty infants admitted to the neonatal intensive care unit, with indwelling arterial catheters placed for their ongoing care, were enrolled. Median gestational age was 31 weeks (range, 24 to 40 weeks), and the mean birth weight was 1711 gm (range, 546 to 3856 gm). Blood pressure was recorded by an oscillometric method as well as from a transducer connected to an arterial catheter. Additionally, pulse oximeter blood pressures were obtained by gradually inflating an appropriately sized blood pressure cuff in increments of 2 to 5 mm Hg, on the same extremity as the oximeter probe, until the waveform just disappeared. The cuff was then rapidly inflated another 20 mm Hg and then gradually deflated in increments of 2 to 5 mm Hg until the waveform reappeared on the oximeter screen display. The pulse oximeter blood pressures were calculated both as the blood pressure noted at disappearance of the pulse oximeter waveform and as the blood pressure noted by the average pulse oximeter blood pressure at the disappearance and reappearance of the waveform. The mean intraarterial systolic blood pressure was 54 mm Hg (range, 36 to 82 mm Hg). Blood pressures obtained by pulse oximetry showed a significantly better correlation with intraarterial measurements in comparison with those obtained by oscillometric instruments. Additionally, the limits of agreement (mean difference +/- 2 SD) between blood pressures obtained by intraarterial measurements and those obtained by pulse oximetry were within a clinically acceptable range as opposed to those obtained by the comparison of intraarterial and oscillometric methods. Measurements of blood pressure in the neonate by means of pulse oximetry waveform analysis are easily obtainable and more accurate than those obtained by the oscillometric method.

  7. Tensile Strength of Water Exposed to Pressure Pulses

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Mørch, Knud Aage

    2012-01-01

    at an extended water-solid interface by imposing a tensile stress pulse which easily causes cavitation. Next, a compressive pulse of duration ~1 ms and a peak intensity of a few bar is imposed prior to the tensile stress pulse. A dramatic increase of the tensile strength is observed immediately after...... 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....

  8. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Entire Site Health Topics News & Resources Intramural Research Public Health Topics Education & Awareness Resources Contact The Health Information ... Contact Us FAQs Home » Health Information for the Public » Health Topics » High Blood Pressure » Diagnosis of High Blood ...

  9. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... happens because medicines can change the way your body controls fluid and salt balances, cause your blood vessels to constrict, or impact the renin-angiotensin-aldosterone system leading to high blood pressure. Other Medical Causes of High Blood ... these other conditions change the way your body controls fluids, sodium, and hormones in your blood, which leads ...

  10. Social support and loneliness in college students: effects on pulse pressure reactivity to acute stress.

    Science.gov (United States)

    O'Donovan, Aoife; Hughes, Brian

    2007-01-01

    Socially supportive relationships at university may buffer against psychological stress in students, particularly in those experiencing loneliness. To examine the relation of social support at university and loneliness with pulse pressure (PP) reactivity to acute psychological stress in a sample of first-year undergraduate students. Sixty-five female, adolescent, first-year university students. Pulse pressure (PP) was calculated as the arithmetic difference between systolic blood pressure and diastolic blood pressure, which were measured during a resting baseline and during a stressful reading task. The difference between baseline and reading task PP represents PP reactivity. The Social Support at University Scale (SSUS) was used to assess social support availability in university, and the Revised UCLA Loneliness Scale was used to assess loneliness. Hierarchical linear regression was used to examine main and interactive effects of SSUS and loneliness on PP change scores, and simple slopes were computed to assist in the interpretation of interaction effects. Social support at university was associated with lower PP reactivity in students reporting medium (t = -2.03, p = .04) or high levels of loneliness (t = -2.93, p = .004), but not in those reporting low levels of loneliness (t = -0.20, p = .83). Psychosocial interventions designed to increase social support available at university, and targeted at students experiencing loneliness may buffer against the harmful effects of acute stressors in lonely first-year students.

  11. High frequency pressure oscillator for microcryocoolers

    NARCIS (Netherlands)

    Vanapalli, Srinivas; ter Brake, Hermanus J.M.; Jansen, Henricus V.; Zhao, Yiping; Holland, Herman J.; Burger, Johannes Faas; Elwenspoek, Michael Curt

    2008-01-01

    Microminiature pulse tube cryocoolers should operate at a frequency of an order higher than the conventional macro ones because the pulse tube cryocooler operating frequency scales inversely with the square of the pulse tube diameter. In this paper, the design and experiments of a high frequency

  12. High pressure gas laser technology for atmospheric remote sensing

    Science.gov (United States)

    Javan, A.

    1980-01-01

    The development of a fixed frequency chirp-free and highly stable intense pulsed laser made for Doppler wind velocity measurements with accurate ranging is described. Energy extraction from a high pressure CO2 laser at a tunable single mode frequency is also examined.

  13. Prediction of systolic blood pressure using peripheral pulse palpation in cats.

    Science.gov (United States)

    Reineke, Erica L; Rees, Colleen; Drobatz, Kenneth J

    2016-01-01

    To evaluate the ability of peripheral pulse palpation to predict systolic blood pressure (SBP) in cats presenting as emergencies. Prospective observational study performed over an 8-month period. University veterinary teaching hospital. One hundred two cats presenting to the emergency service. Eligibility for inclusion in the study included a physical examination and a SBP via Doppler technique performed prior to treatment. None. Femoral and metatarsal pulses were digitally palpated and the quality of the pulses was assessed as either strong, moderate, poor, or absent. A concurrent SBP was also recorded. The median SBP for all cats was 92.5 mm Hg (range, 30-240 mm Hg). Femoral pulse quality was found to strongly correlate with the admission SBP (P cats with either absent or strong pulses was significantly different (P Cats with absent metatarsal and femoral pulses had a median SBP of 30 mm Hg (range, 30-105 mm Hg), whereas cats with strong metatarsal pulses had a median SBP of 135 mm Hg (range, 58-210 mm Hg). Absent metatarsal pulses correctly identified cats with a blood pressure of 75 mm Hg or less 84% the time (area under the curve: 0.89, confidence interval 0.81, 0.97). In cats, peripheral pulse quality assessment by emergency room veterinarians correlates with SBP. With progressive decreases in blood pressure, metatarsal pulses will disappear and it is only with severe hypotension that femoral pulses are absent. An assessment of both dorsal metatarsal pulse and femoral pulse quality during triage may be useful in identifying abnormalities in blood pressure. © Veterinary Emergency and Critical Care Society 2015.

  14. Daily changes in oxygen saturation and pulse rate associated with particulate air pollution and barometric pressure.

    Science.gov (United States)

    Dockery, D W; Pope, C A; Kanner, R E; Martin Villegas, G; Schwartz, J

    1999-01-01

    Epidemiologic studies have linked fine particulate air pollution with increases in morbidity and mortality rates from cardiopulmonary complications. Although the underlying biologic mechanisms responsible for this increase remain largely unknown, potential pathways include transient declines in blood oxygenation and changes in pulse rate following exposures to particulate air pollution episodes. This study evaluated potential associations between daily measures of respirable particulate matter (PM) with pulse rate and oxygen saturation of the blood. Pulse rate and oxygen saturation (Spo2) using pulse oximetry were measured daily in 90 elderly subjects living near air pollution monitors during the winter of 1995-96 in Utah Valley. We also evaluated potential associations of oxygen saturation and pulse rate with barometric pressure. Small but statistically significant positive associations between day-to-day changes in Spo2 and barometric pressure were observed. Pulse rate was inversely associated with barometric pressure. Exposure to particulate pollution was not significantly associated with Spo2 except in male participants 80 years of age or older. Increased daily pulse rate, as well as the odds of having a pulse rate 5 or 10 beats per minute (bpm) above normal (normal is defined as the individual's mean pulse rate throughout the study period), were significantly associated with exposure to particulate pollution on the previous 1 to 5 days. The medical or biologic relevance of these increases in pulse rate following exposure to particulate air pollution requires further study.

  15. Automatic algorithm for monitoring systolic pressure variation and difference in pulse pressure.

    Science.gov (United States)

    Pestel, Gunther; Fukui, Kimiko; Hartwich, Volker; Schumacher, Peter M; Vogt, Andreas; Hiltebrand, Luzius B; Kurz, Andrea; Fujita, Yoshihisa; Inderbitzin, Daniel; Leibundgut, Daniel

    2009-06-01

    Difference in pulse pressure (dPP) reliably predicts fluid responsiveness in patients. We have developed a respiratory variation (RV) monitoring device (RV monitor), which continuously records both airway pressure and arterial blood pressure (ABP). We compared the RV monitor measurements with manual dPP measurements. ABP and airway pressure (PAW) from 24 patients were recorded. Data were fed to the RV monitor to calculate dPP and systolic pressure variation in two different ways: (a) considering both ABP and PAW (RV algorithm) and (b) ABP only (RV(slim) algorithm). Additionally, ABP and PAW were recorded intraoperatively in 10-min intervals for later calculation of dPP by manual assessment. Interobserver variability was determined. Manual dPP assessments were used for comparison with automated measurements. To estimate the importance of the PAW signal, RV(slim) measurements were compared with RV measurements. For the 24 patients, 174 measurements (6-10 per patient) were recorded. Six observers assessed dPP manually in the first 8 patients (10-min interval, 53 measurements); no interobserver variability occurred using a computer-assisted method. Bland-Altman analysis showed acceptable bias and limits of agreement of the 2 automated methods compared with the manual method (RV: -0.33% +/- 8.72% and RV(slim): -1.74% +/- 7.97%). The difference between RV measurements and RV(slim) measurements is small (bias -1.05%, limits of agreement 5.67%). Measurements of the automated device are comparable with measurements obtained by human observers, who use a computer-assisted method. The importance of the PAW signal is questionable.

  16. Fiber Bragg grating sensors written by femtosecond laser pulses in micro-structured fiber for downhole pressure monitoring

    Science.gov (United States)

    Huang, J.-Y.; Van Roosbroeck, J.; Bueno Martinez, A.; Geernaert, T.; Berghmans, F.; Caucheteur, C.; Van Hoe, B.; Lindner, E.; Vlekken, J.

    2017-04-01

    In this paper, we demonstrate that femtosecond laser pulse written fiber Bragg gratings (FBGs) fabricated in specialty highly birefringent micro-structured optical fiber (MSF) can be used for high pressure and high temperature monitoring in downhole applications. The design of the micro-structure allows encoding the pressure information into the spectral separation between the two Bragg peaks reflected by the obtained MS-FBG. We obtained a differential pressure sensitivity of 3.30 pm/bar over a pressure range from atmospheric up to 1400 bar and at temperatures between 40 °C and 290 °C. Owing to the negligible differential pressure-temperature cross-sensitivity of 6.06E-3 bar/°C, the proposed MSFBG sensor is an ideal candidate for pressure monitoring in the presence of high temperature transients.

  17. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... which blood flows through blood vessels (arteries) at higher than normal pressures. Measuring Blood Pressure Blood pressure ... blood pressure are defined as having blood pressures higher than 120/80 mmHg. The following table outlines ...

  18. Highly Supersonic Ion Pulses in a Collisionless Magnetized Plasma

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Schrittwieser, R.

    1982-01-01

    The initial transient response of a collisionless plasma to a high positive voltage step is investigated. Four different pulses are observed. An electron plasma wave pulse is followed by an ion burst. The latter is overtaken and absorbed by a highly supersonic ion pulse. Thereafter, an ion...

  19. High Blood Pressure: Medicines to Help You

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women High Blood Pressure--Medicines to Help You Share Tweet Linkedin Pin ... Click here for the Color Version (PDF 533KB) High blood pressure is a serious illness. High blood pressure is ...

  20. Anxiety: A Cause of High Blood Pressure?

    Science.gov (United States)

    ... cause of high blood pressure? Can anxiety cause high blood pressure? Answers from Sheldon G. Sheps, M.D. Anxiety doesn't cause long-term high blood pressure (hypertension). But episodes of anxiety can cause dramatic, ...

  1. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... NHLBI About NHLBI Home Mission and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees Budget ... health and can lower high blood pressure. Stress management techniques include: ... guidelines now define hypertension as a systolic blood... View all news ...

  2. Vital Signs - High Blood Pressure

    Centers for Disease Control (CDC) Podcasts

    2012-10-02

    In the U.S., nearly one third of the adult population have high blood pressure, the leading risk factor for heart disease and stroke - two of the nation's leading causes of death.  Created: 10/2/2012 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/17/2012.

  3. Diagnosis of High Blood Pressure

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    Full Text Available ... Trials Publications and Resources Health Education and Awareness The Science Science Home Blood Disorders and Blood Safety Sleep ... eating plan if you have high blood pressure. The DASH eating plan focuses on fruits, vegetables, whole grains, and other foods that are heart healthy ...

  4. Diagnosis of High Blood Pressure

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    Full Text Available ... at a higher risk for heart disease and type 2 diabetes. This risk may be high with a waist ... raise your blood pressure and triglyceride levels, a type of fat found in the ... have no more than one drink containing alcohol a day. One drink is: ...

  5. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... compared with readings taken in any other location. Health care providers diagnose this type of high blood pressure by reviewing readings in the office and readings taken anywhere else. Researchers believe stress, which can occur during the medical appointment, causes ...

  6. Diagnosis of High Blood Pressure

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    Full Text Available ... Health Topics Education & Awareness Resources Contact The Health Information Center Health Professionals Systematic Evidence Reviews & Clinical Practice ... Advisory Committees Jobs Contact Us FAQs Home » Health Information for the Public » Health Topics » High Blood Pressure » ...

  7. Diagnosis of High Blood Pressure

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    Full Text Available ... condition is called isolated systolic hypertension (ISH). Many older adults have this condition. ISH can cause as much ... About 65 percent of Americans age 60 or older have high blood pressure. However, ... American adults than in Caucasian or Hispanic American adults. Compared ...

  8. Diagnosis of High Blood Pressure

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    Full Text Available ... cope with problems can improve your emotional and physical health and can lower high blood pressure. Stress management ... their experiences with clinical research. More Information Related Health ... Artery Disease Physical Activity and Your Heart Smoking and Your Heart ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... and Your Heart U.S. Department of Health and Human Services' 2008 Physical Activity Guidelines for Americans Maintaining a Healthy Weight Maintaining a healthy weight can help you control high blood pressure and reduce your risk for ...

  10. Diagnosis of High Blood Pressure

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    Full Text Available ... obese . The terms “overweight” and “obese” refer to body weight that’s greater than what is considered healthy for a certain height. Gender Before age 55, men are more likely than women to develop high blood pressure. After age 55, ...

  11. Diagnosis of High Blood Pressure

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    Full Text Available ... you what you need to know about choosing foods that are lower in sodium. Try to eat no more than 2,300 mg sodium a day. If you have high blood pressure, you may need to restrict your sodium intake even more. Your health care provider ...

  12. Diagnosis of High Blood Pressure

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    Full Text Available ... 1½ ounces of liquor Managing and Coping With Stress Learning how to manage stress, relax, and cope with problems can improve your ... physical health and can lower high blood pressure. Stress management techniques include: Being physically active Listening to ...

  13. Diagnosis of High Blood Pressure

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    Full Text Available ... Accessible Search Form Search the NHLBI, use the drop down list to select: the entire site, the Health Topics section only, or the News and Resources section. NHLBI ... for Health Professionals What Is High blood pressure is a common disease in which blood flows through blood vessels (arteries) ...

  14. Diagnosis of High Blood Pressure

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    Full Text Available ... this system cause high blood pressure. Blood Vessel Structure and Function Changes in the structure and function of small and large arteries may ... su presión arterial alta Hispanic Community Health Study Data Book In Brief: Your Guide to Lowering Your ...

  15. Ultrasonic depth gauge for liquids under high pressure

    Science.gov (United States)

    Zuckerwar, Allan J. (Inventor); Mazel, David S. (Inventor)

    1988-01-01

    The invention relates to an ultrasonic depth gauge for liquids under high pressure and is particularly useful in the space industry where it is necessary to use a pressurized gas to transfer a liquid from one location to another. Conventional liquid depth gauges do not have the capability to operate under extreme high pressure (i.e., exceeding 300 psi). An ultrasonic depth gauge capable of withstanding high pressure according to the present invention is comprised of a transducer assembly and a supporting electronics unit. The former is mounted in to the bottom wall of a storage vessel with its resonating surface directly exposed to the highly pressurized liquid in the vessel. In operation, the ultrasonic pulse propagates upward through the liquid to the liquid-gas interface in the storage vessel. When the ultrasonic echo returns from the liquid-gas interface, it re-excites the composite resonator into vibration. The supporting electronics unit measures the round-trip transmit time for the ultrasonic pulse and its return echo to traverse the depth of the highly pressurized liquid. The novelty of the invention resides in the use of a conventional transducer rigidly bonded to the inside wall of a bored out conventional high-pressure plug to form a composite resonator capable of withstanding extremely high pressure.

  16. High Pressure Treatment in Foods

    Directory of Open Access Journals (Sweden)

    Edwin Fabian Torres Bello

    2014-08-01

    Full Text Available High hydrostatic pressure (HHP, a non-thermal technology, which typically uses water as a pressure transfer medium, is characterized by a minimal impact on food characteristics (sensory, nutritional, and functional. Today, this technology, present in many food companies, can effectively inactivate bacterial cells and many enzymes. All this makes HHP very attractive, with very good acceptance by consumers, who value the organoleptic characteristics of products processed by this non-thermal food preservation technology because they associate these products with fresh-like. On the other hand, this technology reduces the need for non-natural synthetic additives of low consumer acceptance.

  17. High-field/high-pressure ESR.

    Science.gov (United States)

    Sakurai, T; Okubo, S; Ohta, H

    2017-07-01

    We present a historical review of high-pressure ESR systems with emphasis on our recent development of a high-pressure, high-field, multi-frequency ESR system. Until 2000, the X-band system was almost established using a resonator filled with dielectric materials or a combination of the anvil cell and dielectric resonators. Recent developments have shifted from that in the low-frequency region, such as X-band, to that in multi-frequency region. High-pressure, high-field, multi-frequency ESR systems are classified into two types. First are the systems that use a vector network analyzer or a quasi-optical bridge, which have high sensitivity but a limited frequency region; the second are like our system, which has a very broad frequency region covering the THz region, but lower sensitivity. We will demonstrate the usefulness of our high-pressure ESR system, in addition to its experimental limitations. We also discuss the recent progress of our system and future plans. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Estimated Pulse Wave Velocity Calculated from Age and Mean Arterial Blood Pressure

    DEFF Research Database (Denmark)

    Greve, S. V.; Laurent, Stéphane; Olsen, M. H.

    2016-01-01

    In a recently published paper, Greve et al [J Hypertens 2016;34:1279-1289] investigate whether the estimated carotid-femoral pulse wave velocity (ePWV), calculated using an equation derived from the relationship between carotid-femoral pulse wave velocity (cfPWV), age, and blood pressure, predicts...

  19. High voltage high repetition rate pulse using Marx topology

    Science.gov (United States)

    Hakki, A.; Kashapov, N.

    2015-06-01

    The paper describes Marx topology using MOSFET transistors. Marx circuit with 10 stages has been done, to obtain pulses about 5.5KV amplitude, and the width of the pulses was about 30μsec with a high repetition rate (PPS > 100), Vdc = 535VDC is the input voltage for supplying the Marx circuit. Two Ferrite ring core transformers were used to control the MOSFET transistors of the Marx circuit (the first transformer to control the charging MOSFET transistors, the second transformer to control the discharging MOSFET transistors).

  20. Pulse Compression of Phase-matched High Harmonic Pulses from a Time-Delay Compensated Monochromator

    Directory of Open Access Journals (Sweden)

    Ito Motohiko

    2013-03-01

    Full Text Available Pulse compression of single 32.6-eV high harmonic pulses from a time-delay compensated monochromator was demonstrated down to 11±3 fs by compensating the pulse front tilt. The photon flux was intensified up to 5.7×109 photons/s on target by implementing high harmonic generation under a phase matching condition in a hollow fiber used for increasing the interaction length.

  1. Non-invasive measurement of aortic pressure in patients: Comparing pulse wave analysis and applanation tonometry

    OpenAIRE

    Naidu, M.U.R.; C Prabhakar Reddy

    2012-01-01

    Objective: The aim of the present study was to validate and compare novel methods to determine aortic blood pressure non-invasively based on Oscillometric Pulse Wave Velocity (PWV) measurement using four limb-cuff pressure waveforms and two lead Electrocardiogram (ECG) with a validated tonometric pulse wave analysis system in patients. Materials and Methods: After receiving the consent, in 49 patients with hypertension, coronary artery disease, diabetes mellitus, PWV, and central blood p...

  2. Lower blood pressure and smaller pulse pressure in sleeping pill users: A large-scale cross-sectional analysis.

    Science.gov (United States)

    Sasaki, Nobuo; Fujiwara, Saeko; Ozono, Ryoji; Yamashita, Hidehisa; Kihara, Yasuki

    2017-10-01

    This study aimed to investigate the association between sleeping pill use and hypertension or blood pressure (BP) via a cross-sectional analysis.A total of 11,225 subjects (5875 men and 5350 women) underwent health examinations. We compared the proportion of sleeping pill users among hypertension (n = 5099) and normotensive (n = 6126) participants. We analyzed participants with no intake of antihypertensive medication (n = 7788), comparing the proportions with high systolic BP (SBP) ≥140, high diastolic BP (DBP) ≥90, and high pulse pressure (PP) ≥50 mm Hg across 3 subgroups. These groups were classified according to the sleeping pill use [nonuse group (n = 6869); low-frequency-use group, defined as taking sleeping pills ≤2 days per week (n = 344); and high-frequency-use group, defined as taking sleeping pills ≥3 days per week (n = 575)].In the multivariable-adjusted model, odds of sleeping pill use (odds ratio (OR), 1.14; P Sleeping pills were more frequently required in hypertensive participants than in the normotensive ones. Sleeping pill use may decrease BP and assist in the treatment of high BP in patients with sleep disturbances.

  3. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... sensor, and a blood pressure cuff. With this equipment, they measure: Systolic Pressure: blood pressure when the ... or at other locations that have blood pressure equipment and to keep a written log of all ...

  4. 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...

  5. High pressure effects on fruits and vegetables

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Matser, A.M.

    2016-01-01

    The chapter provides an overview on different high pressure based treatments (high pressure pasteurization, blanching, pressure-assisted thermal processing, pressure-shift freezing and thawing) available for the preservation of fruits and vegetable products and extending their shelf life. Pressure

  6. A method for pressure-pulse suppression in fluid-filled piping

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y.W.; Bielick, E.F. (Argonne National Lab., IL (USA)); Wiedermann, A.H. (IIT Research Inst., Chicago, IL (USA)); Ockert, C.E. (USDOE, Washington, DC (USA))

    1989-01-01

    A simple, nondestructive method to suppress pressure pulses in fluid-filled piping was proposed and theoretically analyzed earlier. In this paper, the proposed method is verified experimentally. The results of experiments performed for the range of parameters of practical importance indicated that the attenuation of pressure pulses was in accordance with the theoretical predictions. This paper describes the experimental setup and the test models of the proposed pulse suppression devices and discusses the experimental results. In particular, the measured attenuation factors are presented and compared with the theoretical predictions. 8 ref., 17 fig., 2 tab.

  7. Laser High-Cycle Thermal Fatigue of Pulse Detonation Engine Combustor Materials Tested

    Science.gov (United States)

    Zhu, Dong-Ming; Fox, Dennis S.; Miller, Robert A.

    2001-01-01

    Pulse detonation engines (PDE's) have received increasing attention for future aerospace propulsion applications. Because the PDE is designed for a high-frequency, intermittent detonation combustion process, extremely high gas temperatures and pressures can be realized under the nearly constant-volume combustion environment. The PDE's can potentially achieve higher thermodynamic cycle efficiency and thrust density in comparison to traditional constant-pressure combustion gas turbine engines (ref. 1). However, the development of these engines requires robust design of the engine components that must endure harsh detonation environments. In particular, the detonation combustor chamber, which is designed to sustain and confine the detonation combustion process, will experience high pressure and temperature pulses with very short durations (refs. 2 and 3). Therefore, it is of great importance to evaluate PDE combustor materials and components under simulated engine temperatures and stress conditions in the laboratory. In this study, a high-cycle thermal fatigue test rig was established at the NASA Glenn Research Center using a 1.5-kW CO2 laser. The high-power laser, operating in the pulsed mode, can be controlled at various pulse energy levels and waveform distributions. The enhanced laser pulses can be used to mimic the time-dependent temperature and pressure waves encountered in a pulsed detonation engine. Under the enhanced laser pulse condition, a maximum 7.5-kW peak power with a duration of approximately 0.1 to 0.2 msec (a spike) can be achieved, followed by a plateau region that has about one-fifth of the maximum power level with several milliseconds duration. The laser thermal fatigue rig has also been developed to adopt flat and rotating tubular specimen configurations for the simulated engine tests. More sophisticated laser optic systems can be used to simulate the spatial distributions of the temperature and shock waves in the engine. Pulse laser high

  8. 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.

  9. Effect of tidal volume, sampling duration, and cardiac contractility on pulse pressure and stroke volume variation during positive-pressure ventilation.

    Science.gov (United States)

    Kim, Hyung Kook; Pinsky, Michael R

    2008-10-01

    Both pulse pressure variation and stroke volume variation during intermittent positive-pressure ventilation predict preload responsiveness. However, because ventilatory and cardiac frequencies are not the same, increasing the number of breaths sampled may increase calculated pulse pressure variation and stroke volume variation because larger (max) and smaller (min) pulse pressure and stroke volume may occur. Tidal volume and contractility may also alter pulse pressure variation and stroke volume variation. We hypothesized that the magnitude of pulse pressure variation would increase with sampling duration, and that both tidal volume and contractility would independently alter pulse pressure variation and stroke volume variation. In seven pentobarbital-anesthetized intact dogs arterial and left ventricular pressure (Millar) and left ventricular volume (Leycom) were measured over 8 intermittent positive-pressure ventilation breaths at tidal volume of 5, 10, 15, and 20 mL/kg (f = 20/min, 40% inspiratory time) under baseline, esmolol (2 mg/min), dobutamine infusions (5 microg/kg/min) and following volume loading (500 mL NaCl). Stroke volume variation was calculated using pulse contour method (PiCCO, Pulsion Medical Systems, Munich, Germany) averaged over 12 secs. Pulse pressure variation was calculated as 100 x (PPmax - PPmin)/PPmean and calculated over 1, 2, 3, 4, 5, 6, 7, or 8 breaths. Pulse pressure variation increased progressively with increasing sampling duration up to but not exceeding five breaths. The effect on sampling duration was increased by greater tidal volume. Esmolol infusion decreased both pulse pressure variation and stroke volume variation as compared with baseline (p variation or stroke volume variation. Sampling duration, tidal volume, and beta-adrenergic blockade differentially alters pulse pressure variation and stroke volume variation during intermittent positive-pressure ventilation. Thus, separate validation is required to define threshold

  10. High reliability low jitter pulse generator

    Science.gov (United States)

    Savage, Mark E.; Stoltzfus, Brian S.

    2013-01-01

    A method and concomitant apparatus for generating pulses comprising providing a laser light source, disposing a voltage electrode between ground electrodes, generating laser sparks using the laser light source via laser spark gaps between the voltage electrode and the ground electrodes, and outputting pulses via one or more insulated ground connectors connected to the voltage electrode.

  11. High pressure processing of meat

    DEFF Research Database (Denmark)

    Grossi, Alberto; Christensen, Mette; Ertbjerg, Per

    Abstract Background: The research of high pressure (HP) processing of meat based foods needs to address how pressure affects protein interactions, aggregation and/or gelation. The understanding of the gel forming properties of myofibrillar components is fundamental for the development of muscle...... based products (Chapleau et al., 2004;Colmenero, 2002). Object: The aim was to study the rheological properties of pork meat emulsion exposed to HP and the effect of HP on the aggregation state of myofibrillar proteins. To address the role of cathepsin in myofibrillar protein degradation the changes...... in the myofibrillar protein pattern and HP-induced change in activity of cathepsin B and L were investigated. Results: In this study we showed that HP treatment of pork meat emulsion, ranging from 0.1 to 800 MPa, induced protein gel formation as shown by the increased Young’s modulus (Fig.1). Analysis of SDS...

  12. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... nervous system has important functions in blood pressure regulation, including heart rate, blood pressure, and breathing rate. ... EVENT The Role of Microbiota in Blood Pressure Regulation Executive Summary June 10, 2016 Bethesda, MD The ...

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... your blood pressure returns to your normal baseline range. Blood pressure normally rises with age and body ... 160 or higher OR 100 or higher The ranges in the table are blood pressure guides for ...

  14. High Pressure Microwave Powered UV Light Sources

    Science.gov (United States)

    Cekic, M.; Frank, J. D.; Popovic, S.; Wood, C. H.

    1997-10-01

    Industrial microwave powered (*electrodeless*) light sources have been limited to quiescent pressures of 300 Torr of buffer gas and metal- halide fills. Recently developed multi-atmospheric electronegative bu lb fills (noble gas-halide excimers, metal halide) require electric field s for ionization that are often large multiples of the breakdown voltage for air. For these fills an auxiliary ignition system is necessary. The most successful scheme utilizes a high voltage pulse power supply and a novel field emission source. Acting together they create localized condition of pressure reduction and high free electron density. This allows the normal microwave fields to drive this small region into avalanche, ignite the bulb, and heat the plasma to it's operating poin t Standard diagnostic techniques of high density discharges are inapplicable to the excimer bulbs, because of the ionic molecular exci ted state structure and absence of self-absorption. The method for temperature determination is based on the equilibrium population of certain vibrational levels of excimer ionic excited states. Electron d ensity was determined from the measurements of Stark profiles of H_β radiation from a small amount of hydrogen mixed with noble gas and halogens. At the present time, high pressure (Te 0.5eV, ne 3 x 10^17 cm-3) production bulbs produce over 900W of radiation in a 30nm band, centered at 30nm. Similarly, these prototypes when loaded with metal-halide bulb fills produce 1 kW of radiation in 30nm wide bands, centered about the wavelength of interest.

  15. a New Approach of Dynamic Blood Pressure Measurement Based on the Time Domain Analysis of the Pulse Wave

    Science.gov (United States)

    Zimei, Su; Wei, Xu; Hui, Yu; Fei, Du; Jicun, Wang; Kexin, Xu

    2009-08-01

    In this study the pulse wave characteristics were used as a new approach to measure the human blood pressure. Based the principle of pulse wave and theory of the elastic vascular, the authors analyzed the characteristic of the pulse waveforms and revealed the characteristics points which could be used to represent the blood pressure. In this investigation the relevant mathematical feature was used to identify the relationship between the blood pressure and pulse wave parameters in a more accurate way. It also provided an experimental basis to carry out continuing non-invasive blood pressure monitoring using the pulse wave method.

  16. Origin of the stabilization of the metastable tetragonal high-pressure phase in SrCuO2 thin films grown on SrTiO3 substrates by pulsed laser deposition

    Science.gov (United States)

    Mihailescu, C. N.; Pasuk, I.; Straticiuc, M.; Nita, C. R.; Pantelica, D.; Giapintzakis, J.

    2014-11-01

    In this work we have systematically investigated the evolution of structure and stoichiometry in SrCuO2 films grown on TiO2-terminated SrTiO3 substrates as a function of the substrate temperature. Depending on the growth temperature SrCuO2/SrTiO3 films can exhibit either a pure tetragonal high-pressure phase, or a pure orthorhombic low-pressure phase, or a mixed phase. Our results indicate that at low substrate temperatures the non-equilibrium state of the growth process is responsible for the stabilization of the metastable tetragonal high-pressure structure in SrCuO2 thin films grown on (0 0 1) SrTiO3 substrates, whose lattice matches the metastable structure. In addition, at higher substrate temperatures thermodynamics become dominant over other factors and the SrCuO2 thin films are stabilized in the thermodynamically stable orthorhombic phase.

  17. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... System Activity The sympathetic nervous system has important functions in blood pressure regulation, including heart rate, blood pressure, and breathing rate. Researchers are ...

  18. High-Pressure Minerals in RC106: Formation at Modest Shock Pressures and very High Temperatures

    Science.gov (United States)

    Sharp, T. G.; Trickey, R.; de Carli, P. S.; Xie, Z.

    2009-12-01

    . Although a local pressure spike may have accompanied melt-vein formation, such a spike would have rung down to the equilibrium shock pressure in less than a millisecond. The exclusive formation of high-pressure minerals in the melt vein is a result of the local high-temperature conditions occurring over a relatively long shock pulse. Shock recovery experiments do not reproduce these high-pressure minerals because they do not produce the high temperatures, rapid quench rates and long shock durations that shocked chondrites have experienced.

  19. Pulsed metastable atom source for low vapour-pressure metals

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Urena, A.; Verdasco Costales, E. (Universidad Complutense de Madrid (Spain). Facultad de Quimica); Saez Rabanos, V. (Universidad Politecnica de Madrid (Spain). Escuela Tecnica Superior de Ingenieros Industriales)

    1990-03-01

    The basic design and most relevant experimental conditions of a pulsed metastable atomic-beam oven are described. The stainless steel oven is suitable for vaporising metals and salts up to around 1400 K producing intense beams of metastable alkaline-earth atoms when pulsed or continuous wave low voltage discharges are used. Several applications using atomic calcium in its {sup 3}P and {sup 1}D electronic state are reported. The beam characterisation and discharge efficiency have been measured by time-of-flight or laser-induced fluorescence techniques. In addition, a method of changing the metastable n{sup 3}P/n{sup 1}D ratio, by raising the oven temperature, is described which looks very promising for the study of electronic selectivity in reactive collision processes. Finally several spectroscopic applications for atomic and molecular beam determinations are reported. (author).

  20. Comparative study of pressure- and volume-controlled ventilation on pulse pressure variation in a model of hypovolaemia in rabbits.

    Science.gov (United States)

    Fonseca, E B; Otsuki, D A; Fantoni, D T; Bliacheriene, F; Auler, J O C

    2008-05-01

    Dynamic indices represented by systolic pressure variation and pulse pressure variation have been demonstrated to be more accurate than filling pressures in predicting fluid responsiveness. However, the literature is scarce concerning the impact of different ventilatory modes on these indices. We hypothesized that systolic pressure variation or pulse pressure variation could be affected differently by volume-controlled ventilation and pressure-controlled ventilation in an experimental model, during normovolaemia and hypovolaemia. Thirty-two anaesthetized rabbits were randomly allocated into four groups according to ventilatory modality and volaemic status where G1-ConPCV was the pressure-controlled ventilation control group, G2-HemPCV was associated with haemorrhage, G3-ConVCV was the volume-controlled ventilation control group and G4-HemVCV was associated with haemorrhage. In the haemorrhage groups, blood was removed in two stages: 15% of the estimated blood volume withdrawal at M1, and, 30 min later, an additional 15% at M2. Data were submitted to analysis of variance for repeated measures; a value of P ventilation modes. However, when 30% of the estimated blood volume was removed (M2), dynamic parameters became significantly higher in animals under volume-controlled ventilation when compared with those under pressure-controlled ventilation. Under normovolaemia and moderate haemorrhage, dynamic parameters were not influenced by either ventilatory modalities. However, in the second stage of haemorrhage (30%), animals in volume-controlled ventilation presented higher values of systolic pressure variation and pulse pressure variation when compared with those submitted to pressure-controlled ventilation.

  1. Central venous pulse pressure analysis using an R-synchronized pressure measurement system.

    Science.gov (United States)

    Fujita, Yoshihisa; Hayashi, Daisuke; Wada, Shinya; Yoshioka, Naoki; Yasukawa, Takeshi; Pestel, Gunther

    2006-12-01

    The information derived from central venous catheters is underused. We developed an EKG-R synchronization and averaging system to obtained distinct CVP waveforms and analyzed components of these. Twenty-five paralyzed surgical patients undergoing CVP monitoring under mechanical ventilation were studied. CVP and EKG signals were analyzed employing our system, the mean CVP and CVP at end-diastole during expiration were compared, and CVP waveform components were measured using this system. CVP waveforms were clearly visualized in all patients. They showed the a peak to be 1.8+/- 0.7 mmHg, which was the highest of three peaks, and the x trough to be lower than the y trough (-1.6+/- 0.7 mmHg and -0.9+/- 0.5 mmHg, respectively), with a mean pulse pressure of 3.4 mmHg. The difference between the mean CVP and CVP at end-diastole during expiration was 0.58+/- 0.81 mmHg. The mean CVP can be used as an index of right ventricular preload in patients under mechanical ventilation with regular sinus rhythm. Our newly developed system is useful for clinical monitoring and for education in circulatory physiology.

  2. Carbon nanostructures under high pressure

    CERN Document Server

    Sundqvist, B

    2002-01-01

    Results from recent high-pressure experiments in the field of fullerenes are briefly reviewed. In particular, new results on one-, two- and three-dimensional polymerized C sub 6 sub 0 and C sub 7 sub 0 are discussed. Results discussed include the first synthesis of a well defined, one-dimensional polymer based on C sub 7 sub 0 , transformations from two-dimensional (2D) to three-dimensional phases in C sub 6 sub 0 , and doping of 2D C sub 6 sub 0 polymers.

  3. Dendritic cells pulsed with tumor cells killed by high hydrostatic pressure induce strong immune responses and display therapeutic effects both in murine TC-1 and TRAMP-C2 tumors when combined with docetaxel chemotherapy

    Czech Academy of Sciences Publication Activity Database

    Mikyšková, Romana; Štěpánek, Ivan; Indrová, Marie; Bieblová, Jana; Šímová, Jana; Truxová, I.; Moserová, I.; Fučíková, J.; Bartunkova, J.; Špíšek, R.; Reiniš, Milan

    2016-01-01

    Roč. 48, č. 3 (2016), s. 953-964 ISSN 1019-6439 R&D Projects: GA MŠk(CZ) LM2011032; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : dendritic cells * docetaxel * high hydrostatic pressure * immunotherapy * cancer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.079, year: 2016

  4. Ejector-Enhanced, Pulsed, Pressure-Gain Combustor

    Science.gov (United States)

    Paxson, Daniel E.; Dougherty, Kevin T.

    2009-01-01

    An experimental combination of an off-the-shelf valved pulsejet combustor and an aerodynamically optimized ejector has shown promise as a prototype of improved combustors for gas turbine engines. Despite their name, the constant pressure combustors heretofore used in gas turbine engines exhibit typical pressure losses ranging from 4 to 8 percent of the total pressures delivered by upstream compressors. In contrast, the present ejector-enhanced pulsejet combustor exhibits a pressure rise of about 3.5 percent at overall enthalpy and temperature ratios compatible with those of modern turbomachines. The modest pressure rise translates to a comparable increase in overall engine efficiency and, consequently, a comparable decrease in specific fuel consumption. The ejector-enhanced pulsejet combustor may also offer potential for reducing the emission of harmful exhaust compounds by making it practical to employ a low-loss rich-burn/quench/lean-burn sequence. Like all prior concepts for pressure-gain combustion, the present concept involves an approximation of constant-volume combustion, which is inherently unsteady (in this case, more specifically, cyclic). The consequent unsteadiness in combustor exit flow is generally regarded as detrimental to the performance of downstream turbomachinery. Among other adverse effects, this unsteadiness tends to detract from the thermodynamic benefits of pressure gain. Therefore, it is desirable in any intermittent combustion process to minimize unsteadiness in the exhaust path.

  5. Quality and storage-stability of high-pressure preseved green beans

    NARCIS (Netherlands)

    Krebbers, B.; Matser, A.M.; Koets, M.; Berg, van den R.W.

    2002-01-01

    The effects of high-pressure technology on naturally present microbial flora, texture, color, ascorbic acid content and peroxidase activity of whole green beans were evaluated and compared to conventional preservation techniques. High-pressure processing (HPP) and two-pulse pressure treatment (pHPP)

  6. 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.

  7. Plasma response to transient high voltage pulses

    Indian Academy of Sciences (India)

    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 ...

  8. PULSE WAVE VELOCITY AND CENTRAL AORTIC PRESSURE IN OBESE CHILDREN ACCORDING TO THE NON-INVASIVE ARTERIOGRAPHY RESULTS

    Directory of Open Access Journals (Sweden)

    O. V. Kozhevnikova

    2013-01-01

    Full Text Available The article presents information value of non-invasive arteriography, which reveals early signs of cardiovascular pathology formation in children, using a large number of trials in children. The authors examined predictors of cardiovascular catastrophes’ development, confirmed in adults: aortic wall’s stiffness, central aortic pressure and pulse pressure – that have not been sufficiently studied in children yet. The article shows that the high-technology method of non-invasive arteriography allows revealing changes of these parameters in children on the preclinical stage. It also shows their correlation with body mass index, fatty hepatosis, direct correlation of weight gain with connection of pulse wave velocity and central blood pressure and importance of follow-up evaluation of these parameters. Heterogeneity of the group of obese children in terms of these parameters is a premise for development of individual approach to control and prevention of cardiovascular complications’ development risk in childhood.

  9. Cuff-Free Blood Pressure Estimation Using Pulse Transit Time and Heart Rate

    OpenAIRE

    Wang, Ruiping; Jia, Wenyan; Mao, Zhi-Hong; Sclabassi, Robert J.; Sun, Mingui

    2014-01-01

    It has been reported that the pulse transit time (PTT), the interval between the peak of the R-wave in electrocardiogram (ECG) and the fingertip photoplethysmogram (PPG), is related to arterial stiffness, and can be used to estimate the systolic blood pressure (SBP) and diastolic blood pressure (DBP). This phenomenon has been used as the basis to design portable systems for continuously cuff-less blood pressure measurement, benefiting numerous people with heart conditions. However, the PTT-ba...

  10. Pulse pressure monitoring through non-contact cardiac motion detection using 2.45 GHz microwave Doppler radar.

    Science.gov (United States)

    Singh, Aditya; Lubecke, Victor; Boric-Lubecke, Olga

    2011-01-01

    The use of a Continuous Wave (CW) quadrature Doppler radar is proposed here for continuous non-invasive Pulse Pressure monitoring. A correspondence between the variation in systemic pulse and variation in the displacement of the chest due to heart is demonstrated, establishing feasibility for the approach. Arctangent demodulation technique was used to process baseband data from radar measurements on two test subjects, in order to determine the absolute cardiac motion. An Omron digital Blood pressure cuff was used to measure the systolic and diastolic blood pressures from which the pulse pressure was calculated. Correlation between pulse pressure and cardiac motion was observed through changes induced due to different postures of the body.

  11. Pulse Pressure and Risk for Cardiovascular Events in Patients With Atherothrombosis: From the REACH Registry.

    Science.gov (United States)

    Selvaraj, Senthil; Steg, Ph Gabriel; Elbez, Yedid; Sorbets, Emmanuel; Feldman, Laurent J; Eagle, Kim A; Ohman, E Magnus; Blacher, Jacques; Bhatt, Deepak L

    2016-02-02

    Pulse pressure (PP) provides valuable prognostic information in specific populations, but few studies have assessed its value on cardiovascular outcomes in a broad, worldwide population. The aim of this study was to determine whether PP is associated with major adverse cardiovascular outcomes, independently of mean arterial pressure. Participants from the international REACH (Reduction of Atherothrombosis for Continued Health) registry, which evaluates subjects with clinical atherothrombotic disease or risk factors for its development, were examined. Those with incomplete 4-year follow-up or PP data (final n = 45,087) were excluded. Univariate and multivariate regression analyses were performed to determine the association between PP and cardiovascular outcomes, including cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, all myocardial infarction, all stroke, cardiovascular hospitalization, and a combined outcome. PP was analyzed as a continuous and categorical (i.e., by quartile) variable. The mean age of the cohort was 68 ± 10 years, 35% were women, and 81% were treated for hypertension. The mean blood pressure was 138 ± 19/79 ± 11 mm Hg, rendering a mean PP of 49 ± 16 mm Hg. On univariate analysis, increasing PP quartile was associated with worse outcomes (p < 0.05 for all comparisons). After adjusting for sex, age, current smoking status, history of hypercholesterolemia, history of diabetes, aspirin use, statin use, blood pressure medication use, and mean arterial pressure, PP quartile was still associated with all outcomes except all stroke and cardiovascular death (p < 0.05 for all comparisons). Analysis of PP as a continuous variable yielded similar results. In an international cohort of high-risk subjects, PP, a readily available hemodynamic parameter, is associated with multiple adverse cardiovascular outcomes and provides prognostic utility beyond that of mean arterial pressure. Copyright © 2016 American College of

  12. Development of ultra-short high voltage pulse technology using magnetic pulse compression

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L

    1998-01-01

    The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs.

  13. Use of antihypertension agents for the suppression of arterial pulse pressure waveforms in patients with intracranial aneurysms.

    Science.gov (United States)

    Turner, Carole L; Wilkinson, Ian B; Kirkpatrick, Peter J

    2006-04-01

    Patients with intracranial aneurysms tend toward raised blood pressure and abnormal pulse pressure profiles. The authors have investigated the influence of three antihypertension agents on blood pressure and pulse pressure waveforms in patients with known intracranial aneurysms, with a view to assessing the potential benefits of longterm antihypertension therapy on the progression of unruptured intracranial aneurysms. Nineteen patients with a mean age of 56 years (range 38-76 years) were recruited for this study. All patients had confirmed intracranial aneurysms. A double-blind, randomized, crossover study was performed using perindopril, irbesartan, isosorbide mononitrate, and a placebo. Blood pressure and pulse pressure waveforms were assessed at the end of each 4-week treatment period. Perindopril and irbesartan were well tolerated. For all measured parameters except heart rate (p = 0.03), no significant difference between baseline and placebo was identified. Each drug when compared with placebo reduced peripheral arterial blood pressure. Perindopril significantly decreased mean blood pressure by 10 mm Hg (p = 0.004), irbesartan by 9 mm Hg (p = 0.004), and isosorbide mononitrate by 13 mm Hg (p = 0.005). The administration of each drug effected a significant reduction in the carotid artery augmentation index (AIX) compared with baseline values (perindopril p = 0.01, irbesartan p = 0.0002, and isosorbide mononitrate p = 0.03). There was also a significant difference in the AIX between irbesartan and the placebo (p = 0.05). Compared with the placebo, there was a significant difference in AIX (adjusted for heart rate) following the administration of irbesartan (p = 0.003) and isosorbide mononitrate (p = 0.01), but not with perindopril (p = 0.17). Irbesartan appears to be the most effective treatment for the combined suppression of blood pressure and AIX in patients with intracranial aneurysms and has a high degree of patient tolerance.

  14. Hilbert-diagnostics of vortex rings induced in air by a pressure pulse on a hole

    Directory of Open Access Journals (Sweden)

    VA Arbuzov

    2016-09-01

    Full Text Available Formation and evolution of complementary vortical rings induced in air by a pressure pulse on a hole under various boundary conditions are investigated by Hilbert-optics methods and computer modeling. It is experimentally demonstrated that reverse ring-shaped vortices inside the chamber after its depressurization are formed not only in the case with a reduced initial pressure in the chamber as compared with the ambient atmospheric pressure but also in the case with a higher gas pressure in the chamber than the atmospheric pressure. The complementary vortex rings propagating in forward and reverse directions might significantly affect the combustion process in the jets.

  15. 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.

  16. 20 W High Efficiency 1550 nm Pulsed Fiber Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High peak power short pulsed lasers have been considered to be an enabling technology to build high power transmitters for future deep space high rate space...

  17. Effect of Pulse Shaping on Subharmonic Aided Pressure Estimation In Vitro and In Vivo.

    Science.gov (United States)

    Gupta, Ipshita; Eisenbrey, John; Stanczak, Maria; Sridharan, Anush; Dave, Jaydev K; Liu, Ji-Bin; Hazard, Christopher; Wang, Xinghua; Wang, Ping; Li, Huiwen; Wallace, Kirk; Forsberg, Flemming

    2017-01-01

    Subharmonic imaging (SHI) is a technique that uses the nonlinear oscillations of microbubbles when exposed to ultrasound at high pressures transmitting at the fundamental frequency ie, fo and receiving at half the transmit frequency (ie, fo /2). Subharmonic aided pressure estimation (SHAPE) is based on the inverse relationship between the subharmonic amplitude of the microbubbles and the ambient pressure change. Eight waveforms with different envelopes were optimized with respect to acoustic power at which the SHAPE study is most sensitive. The study was run with four input transmit cycles, first in vitro and then in vivo in three canines to select the waveform that achieved the best sensitivity for detecting changes in portal pressures using SHAPE. A Logiq 9 scanner with a 4C curvi-linear array was used to acquire 2.5 MHz radio-frequency data. Scanning was performed in dual imaging mode with B-mode imaging at 4 MHz and a SHI contrast mode transmitting at 2.5 MHz and receiving at 1.25 MHz. Sonazoid, which is a lipid stabilized gas filled bubble of perfluorobutane, was used as the contrast agent in this study. A linear decrease in subharmonic amplitude with increased pressure was observed for all waveforms (r from -0.77 to -0.93; P < .001) in vitro. There was a significantly higher correlation of the SHAPE gradient with changing pressures for the broadband pulses as compared to the narrowband pulses in both in vitro and in vivo results. The highest correlation was achieved with a Gaussian windowed binomial filtered square wave with an r-value of -0.95. One of the three canines was eliminated for technical reasons, while the other two produced very similar results to those obtained in vitro (r from -0.72 to -0.98; P <.01). The most consistent in vivo results were achieved with the Gaussian windowed binomial filtered square wave (r = -0.95 and -0.96). Using this waveform is an improvement to the existing SHAPE technique (where a square wave was used) and

  18. Measurement of high-power microwave pulse under intense ...

    Indian Academy of Sciences (India)

    KALI-1000 pulse power system has been used to generate single pulse nanosecond duration high-power microwaves (HPM) from a virtual cathode oscillator (VIRCATOR) device. HPM power measurements were carried out using a transmitting–receiving system in the presence of intense high frequency (a few MHz) ...

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... or hormone therapies, including birth control pills and estrogen, and over-the-counter medicines such as cold ... pressure. Medicines to lower blood pressure include: Diuretics (Water or Fluid Pills): Flush excess sodium from your ...

  20. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure test is easy and painless and can be done in a health care provider’s office ... severity of your blood pressure, he or she can order additional tests to determine if your blood ...

  1. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure, health care providers recommend that you limit sodium and salt intake, increase potassium, and eat ... manage your blood pressure. You should try to limit the amount of sodium that you eat. This ...

  2. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure readings the same way for children, teens, and adults. They use a gauge, stethoscope or ... that are considered normal for babies, while older teens have numbers similar to adults. Abnormal Blood Pressure ...

  3. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure medicines, sometimes in one combined pill. Beta Blockers: Help your heart beat slower and with less ... freely, causing blood pressure to go down. Alpha-Beta Blockers: Reduce nerve impulses the same way alpha blockers ...

  4. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... track blood pressure readings over a period of time, the health care provider may ask you to ... the office on different days and at different times to take your blood pressure. The health care ...

  5. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... term serious illnesses. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 ... pressure include other medical conditions such as chronic kidney disease , sleep apnea , thyroid problems, or certain tumors. This ...

  6. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Signs and symptoms include memory loss, difficulty finding words, and losing focus during conversations. Eye Damage: When ... pressure. Medicines to lower blood pressure include: Diuretics (Water or Fluid Pills): Flush excess sodium from your ...

  7. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... the body’s salt balance by retaining sodium and water and excreting potassium. Imbalances in this kidney function ... pressure. Medicines to lower blood pressure include: Diuretics (Water or Fluid Pills): Flush excess sodium from your ...

  8. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... narrow, which can lower your blood pressure. Calcium Channel Blockers: Keep calcium from entering the muscle cells ... talk with your health care provider and take steps to control your blood pressure by making healthy ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... families. Genetic causes of this condition are why family history is a risk factor for ... blood pressure regularly. Children should have their blood pressure checked starting at ...

  10. Diagnosis of High Blood Pressure

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    Full Text Available ... talk with your health care provider and take steps to control your blood pressure by making healthy ... your health care team so you can take steps to control your blood pressure before and during ...

  11. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... normal for babies, while older teens have numbers similar to adults. Abnormal Blood Pressure Abnormal increases in ... Salt A low-sodium diet can help you manage your blood pressure. You should try to limit ...

  12. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... short-term serious illnesses. People with diabetes or chronic kidney disease should keep their blood pressure below ... blood pressure include other medical conditions such as chronic kidney disease , sleep apnea , thyroid problems, or certain ...

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... bring your log of blood pressure readings. Every time you visit the health care provider, he or she should tell you what your blood pressure numbers are; if he or she does not, you should ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure. Angiotensin-Converting Enzyme (ACE) Inhibitors : Angiotensin-II is a hormone that narrows blood vessels, increasing blood pressure. ACE converts Angiotensin I to Angiotensin II. ACE inhibitors block this process, which stops the ...

  15. High blood pressure and eye disease

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000999.htm High blood pressure and eye disease To use the sharing features on this page, please enable JavaScript. High blood pressure can damage blood vessels in the retina . The ...

  16. 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.

  17. Poor agreement between respiratory variations in pulse oximetry photoplethysmographic waveform amplitude and pulse pressure in intensive care unit patients.

    Science.gov (United States)

    Landsverk, Svein Aslak; Hoiseth, Lars O; Kvandal, Per; Hisdal, Jonny; Skare, Oivind; Kirkeboen, Knut A

    2008-11-01

    To identify fluid responsiveness, a correlation between respiratory variations in pulse pressure (DeltaPP) and respiratory variations in pulse oximetry photoplethysmographic waveform amplitude (DeltaPOP) in mechanically ventilated patients has been demonstrated. To evaluate the agreement between the two methods, knowledge about the repeatability of the methods is imperative. However, no such data exist. Based on knowledge of slow oscillation in skin blood flow, the authors hypothesized that the variability of DeltaPOP would be larger than that of DeltaPP when calculations were performed continuously over a long recording period. Respiration, continuous invasive blood pressure, pulse oximetry, and skin microcirculation were recorded in 14 mechanically ventilated intensive care unit patients. No intravenous fluid challenges were given, and no other interventions were performed during the measurements. Seventy consecutive comparisons between DeltaPP and DeltaPOP were calculated for each of the 14 patients. For all patients, DeltaPOP was 13.7 +/- 5.8% and DeltaPP was 5.8 +/- 2.6% (P intensive care unit patients. This is in contrast to DeltaPP, which shows a small variability.

  18. 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.

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

    Science.gov (United States)

    Pérez, J. A.; Riascos, H.; Caicedo, J. C.; Cabrera, G.; Yate, L.

    2011-01-01

    AlN films were deposited by pulsed laser deposition technique (PLD) using an Nd: YAG laser (λ = 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 °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.

  20. High pressure metrology for industrial applications

    Science.gov (United States)

    Sabuga, Wladimir; Rabault, Thierry; Wüthrich, Christian; Pražák, Dominik; Chytil, Miroslav; Brouwer, Ludwig; Ahmed, Ahmed D. S.

    2017-12-01

    To meet the needs of industries using high pressure technologies, in traceable, reliable and accurate pressure measurements, a joint research project of the five national metrology institutes and the university was carried out within the European Metrology Research Programme. In particular, finite element methods were established for stress–strain analysis of elastic and nonlinear elastic–plastic deformation, as well as of contact processes in pressure-measuring piston-cylinder assemblies, and high-pressure components at pressures above 1 GPa. New pressure measuring multipliers were developed and characterised, which allow realisation of the pressure scale up to 1.6 GPa. This characterisation is based on research including measurements of material elastic constants by the resonant ultrasound spectroscopy, hardness of materials of high pressure components, density and viscosity of pressure transmitting liquids at pressures up to 1.4 GPa and dimensional measurements on piston-cylinders. A 1.6 GPa pressure system was created for operation of the 1.6 GPa multipliers and calibration of high pressure transducers. A transfer standard for 1.5 GPa pressure range, based on pressure transducers, was built and tested. Herewith, the project developed the capability of measuring pressures up to 1.6 GPa, from which industrial users can calibrate their pressure measurement devices for accurate measurements up to 1.5 GPa.

  1. Depth Gauge for Liquids Under High Pressure

    Science.gov (United States)

    Zuckerwar, A. J.; Mazel, D. S.

    1987-01-01

    Piezoelectric element mounted in hole drilled in high-pressure plug. Transducer used to measure depth of liquid when pressure in vessel high. New configuration transmits ultrasonic vibration directly into liquid, enhancing signal strength, accuracy, and range, yet piezoelectric element protected from high-pressure liquid.

  2. A compact high-voltage pulse generator based on pulse transformer with closed magnetic core.

    Science.gov (United States)

    Zhang, Yu; Liu, Jinliang; Cheng, Xinbing; Bai, Guoqiang; Zhang, Hongbo; Feng, Jiahuai; Liang, Bo

    2010-03-01

    A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.

  3. Abdominal Obesity Is Characterized by Higher Pulse Pressure: Possible Role of Free Triiodothyronine

    Directory of Open Access Journals (Sweden)

    Giovanni De Pergola

    2012-01-01

    Full Text Available Objective. This study examined whether obesity is characterized by higher 24 h mean pulse pressure (24 h mean SBP-24 h mean DBP and whether free thyroid hormones (FT3 and FT4 have a relationship with 24 h mean pulse pressure. Methods. A total of 231 euthyroid overweight and obese patients, 103 women and 128 men, aged 18–68 yrs, normotensive ( or with recently developed hypertension (, never treated with antihypertensive drugs, were investigated. Fasting insulin, TSH, FT3, FT4, glucose, and lipid serum concentrations were measured. Waist circumference was measured as an indirect parameter of central fat accumulation. Ambulatory blood pressure monitoring (ABPM was performed. Results. 24 h mean pulse pressure (PP showed a significant positive correlation with BMI (, waist circumference (, and FT3 ( and insulin serum levels (. When a multivariate analysis was performed, and 24 h PP was considered as the dependent variable, and waist circumference, FT3, insulin, male sex, and age as independent parameters, 24 h mean PP maintained a significant association only with waist circumference ( and FT3 levels (. Conclusion. Our results suggest that FT3 per se may contribute to higher pulse pressure in obese subjects.

  4. World of high pressure. Koatsuryoku no sekai

    Energy Technology Data Exchange (ETDEWEB)

    Moritoki, M.; Kanda, T. (Kobe Steel, Ltd., Kobe (Japan))

    1993-05-01

    The present article describes development and current status of high pressure technology. It introduces applications of high pressure technology to chemical reactions and processings, utilizations of phase changes and supercritical fluids, and applications of high pressure to food processings. Contributions of high pressure technology to synthetic chemistry are mentioned as for industrialization of syntheses of ammonia, urea and methanol, and invention of synthesis of polyethylene. Processing technologies utilizing high pressure are also mentioned as for cold isostatic pressing, hot isostatic pressing, hydrostatic extrusion technique, water jet working technique, and explosive forming technique. Introduced are application of phase changes under high pressure, such as high pressure synthesis of diamond and pressurized crystallization technology, and supercritical extraction technology using water and carbon dioxide. Pressurized food processings of mandarin orange, jam, and grapefruit are described. Furthermore, current status of fundamental technologies of high pressure installations is provided as for pressure vessel technology, pressure generation and control technology, and pressure sealing technology. 12 refs., 15 figs., 1 tab.

  5. High pulse energy, high beam quality microsecond-pulse Ti:sapphire laser at 819.7 nm

    Science.gov (United States)

    Xu, Chang; Guo, Chuan; Yu, Hai-Bo; Wang, Zhi-Min; Zuo, Jun-Wei; Xia, Yuan-Qin; Bian, Qi; Bo, Yong; Gao, Hong-Wei; Guo, Ya-Ding; Zhang, Sheng; Cui, Da-Fu; Peng, Qin-Jun; Xu, Zu-Yan

    2017-03-01

    In this letter, a high pulse energy and high beam quality 819.7 nm Ti:sapphire laser pumped by a frequency-doubled Nd:YAG laser is demonstrated. At incident pump energy of 774 mJ, the maximum output energy of 89 mJ at 819.7 nm with a pulse width of 100 μs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, this is the highest pulse energy at 819.7 nm with pulse width of hundred microseconds for a Ti:sapphire laser. The beam quality factor M 2 is measured to be 1.18. This specific wavelength with the high pulse energy and high beam quality at 819.7 nm is a promising light source to create a polychromatic laser guide star together with a home-made 589 nm laser via exciting the sodium atoms in the mesospheric atmosphere.

  6. High-Pressure Lightweight Thrusters

    Science.gov (United States)

    Holmes, Richard; McKechnie, Timothy; Shchetkovskiy, Anatoliy; Smirnov, Alexander

    2013-01-01

    Returning samples of Martian soil and rock to Earth is of great interest to scientists. There were numerous studies to evaluate Mars Sample Return (MSR) mission architectures, technology needs, development plans, and requirements. The largest propulsion risk element of the MSR mission is the Mars Ascent Vehicle (MAV). Along with the baseline solid-propellant vehicle, liquid propellants have been considered. Similar requirements apply to other lander ascent engines and reaction control systems. The performance of current state-ofthe- art liquid propellant engines can be significantly improved by increasing both combustion temperature and pressure. Pump-fed propulsion is suggested for a single-stage bipropellant MAV. Achieving a 90-percent stage propellant fraction is thought to be possible on a 100-kg scale, including sufficient thrust for lifting off Mars. To increase the performance of storable bipropellant rocket engines, a high-pressure, lightweight combustion chamber was designed. Iridium liner electrodeposition was investigated on complex-shaped thrust chamber mandrels. Dense, uniform iridium liners were produced on chamber and cylindrical mandrels. Carbon/carbon composite (C/C) structures were braided over iridium-lined mandrels and densified by chemical vapor infiltration. Niobium deposition was evaluated for forming a metallic attachment flange on the carbon/ carbon structure. The new thrust chamber was designed to exceed state-of-the-art performance, and was manufactured with an 83-percent weight savings. High-performance C/Cs possess a unique set of properties that make them desirable materials for high-temperature structures used in rocket propulsion components, hypersonic vehicles, and aircraft brakes. In particular, more attention is focused on 3D braided C/Cs due to their mesh-work structure. Research on the properties of C/Cs has shown that the strength of composites is strongly affected by the fiber-matrix interfacial bonding, and that weakening

  7. Blood pressure estimation from pulse wave velocity measured on the chest.

    Science.gov (United States)

    Puke, Sawa; Suzuki, Takuji; Nakayama, Kanako; Tanaka, Hirokazu; Minami, Shigenobu

    2013-01-01

    Recently, monitoring of blood pressure fluctuation in the daily life is focused on in the hypertension care area to predict the risk of cardiovascular and cerebrovascular disease events. In this paper, in order to propose an alternative system to the existed ambulatory blood pressure monitoring (ABPM) sphygmomanometer, we have developed a prototype of small wearable device consisting of electrocardiogram (ECG) and photopelthysmograph (PPG) sensors. In addition, it was examined whether blood pressure can be estimated based on pulse wave transit time (PWTT) only by attaching that device on the surface of the chest. We indicated that our system could also sense tendency of time-dependent change of blood pressure by measuring pulse of vessel over the sternum while its propagation distance is short.

  8. Non-invasive measurement of the blood pressure pulse using multiple PPGs

    Science.gov (United States)

    Seymour, John; Pennington, Gary

    Heart disease, the leading cause of death in the US, may be spotted early on by looking at photoplethysmogram (PPG) data. This experiment explores a new method of continuously monitoring the blood pressure pulse with PPG data. In contrast to the traditional sphygmomanometer (cuff) method, which yields only the systolic and diastolic pressure during measurement, this method tracks the blood pressure pulse wave in a non-invasive continuous manner. This procedure allows for fast, inexpensive, and detailed analysis of the patient's blood pressure implementable on a large scale. We also explore the second derivative of the PPG data. In combination with the above method, the patient's heart risk can be effectively detected. We acknowledge Fisher Endowment Grant support from the Jess and Mildred Fisher College of Science and Mathematics, Towson University.

  9. Coherent pulse interrogation system for fiber Bragg grating sensing of strain and pressure in dynamic extremes of materials.

    Science.gov (United States)

    Rodriguez, George; Jaime, Marcelo; Balakirev, Fedor; Mielke, Chuck H; Azad, Abul; Marshall, Bruce; La Lone, Brandon M; Henson, Bryan; Smilowitz, Laura

    2015-06-01

    A 100 MHz fiber Bragg grating (FBG) interrogation system is described and applied to strain and pressure sensing. The approach relies on coherent pulse illumination of the FBG sensor with a broadband short pulse from a femtosecond modelocked erbium fiber laser. After interrogation of the FBG sensor, a long multi-kilometer run of single mode fiber is used for chromatic dispersion to temporally stretch the spectral components of the reflected pulse from the FBG sensor. Dynamic strain or pressure induced spectral shifts in the FBG sensor are detected as a pulsed time domain waveform shift after encoding by the chromatic dispersive line. Signals are recorded using a single 35 GHz photodetector and a 50 G Samples per second, 25 GHz bandwidth, digitizing oscilloscope. Application of this approach to high-speed strain sensing in magnetic materials in pulsed magnetic fields to ~150 T is demonstrated. The FBG wavelength shifts are used to study magnetic field driven magnetostriction effects in LaCoO3. A sub-microsecond temporal shift in the FBG sensor wavelength attached to the sample under first order phase change appears as a fractional length change (strain: ΔL/L-4) in the material. A second application used FBG sensing of pressure dynamics to nearly 2 GPa in the thermal ignition of the high explosive PBX-9501 is also demonstrated. Both applications demonstrate the use of this FBG interrogation system in dynamical extreme conditions that would otherwise not be possible using traditional FBG interrogation approaches that are deemed too slow to resolve such events.

  10. Controlled production of atomic oxygen and nitrogen in a pulsed radio-frequency atmospheric-pressure plasma

    Science.gov (United States)

    Dedrick, J.; Schröter, S.; Niemi, K.; Wijaikhum, A.; Wagenaars, E.; de Oliveira, N.; Nahon, L.; Booth, J. P.; O’Connell, D.; Gans, T.

    2017-11-01

    Radio-frequency driven atmospheric pressure plasmas are efficient sources for the production of reactive species at ambient pressure and close to room temperature. Pulsing the radio-frequency power input provides additional control over species production and gas temperature. Here, we demonstrate the controlled production of highly reactive atomic oxygen and nitrogen in a pulsed radio-frequency (13.56 MHz) atmospheric-pressure plasma, operated with a small 0.1 % air-like admixture (N2 /O2 at 4:1 ) through variations in the duty cycle. Absolute densities of atomic oxygen and nitrogen are determined through vacuum-ultraviolet absorption spectroscopy using the DESIRS beamline at the SOLEIL synchrotron coupled with a high resolution Fourier-transform spectrometer. The neutral-gas temperature is measured using nitrogen molecular optical emission spectroscopy. For a fixed applied-voltage amplitude (234 V), varying the pulse duty cycle from 10% to 100% at a fixed 10 kHz pulse frequency enables us to regulate the densities of atomic oxygen and nitrogen over the ranges of (0.18+/-0.03) –(3.7+/-0.1)× 1020 m-3 and (0.2+/-0.06) –(4.4+/-0.8) × 1019 m-3 , respectively. The corresponding 11 K increase in the neutral-gas temperature with increased duty cycle, up to a maximum of (314+/-4) K, is relatively small. This additional degree of control, achieved through regulation of the pulse duty cycle and time-averaged power, could be of particular interest for prospective biomedical applications.

  11. 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.

  12. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... your risk for health problems. Greater amounts of weight loss can improve blood pressure readings, lower LDL cholesterol , ... blood pressure and triglyceride levels, a type of fat found in the blood. Alcohol also adds extra calories, which may cause weight gain. Men should have no more than two ...

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... short-term serious illnesses. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 ... blood pressure include other medical conditions such as chronic kidney disease , sleep apnea , thyroid problems, or certain tumors. This ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... provider may ask you to come into the office on different days and at different times to take your blood pressure. The health care provider also may ask you to check readings at home or at other locations that have blood pressure ...

  15. 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

    2017-03-01

    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/m2 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.

  16. Effects of candesartan in hypertensive patients with type 2 diabetes mellitus on inflammatory parameters and their relationship to pulse pressure

    Directory of Open Access Journals (Sweden)

    Sakamoto Masaya

    2012-10-01

    Full Text Available Abstract Background Angiotensin receptor blockers (ARBs are reported to provide direct protection to many organs by controlling inflammation and decreasing oxidant stress in patients without arteriosclerosis. This study aimed to evaluate (1 whether an ARB (candesartan decreases values for inflammatory parameters in hypertensive patients with type 2 diabetes mellitus of long duration accompanied by arteriosclerosis and (2 whether there any predictors of which patients would receive the benefits of organ protection by candesartan. Methods We administered candesartan therapy (12 mg daily for 6 months and evaluated whether there was improvement in serum inflammatory parameters high molecular weight adiponectin (HMW-ADN, plasminogen activator inhibitor-1 (PAI-1, highly sensitive C-reactive protein (Hs-CRP, vascular cell adhesion molecule-1 (VCAM-1 in serum and urinary-8-hydroxydeoxyguanosine (U-8-OHdG. We then analyzed the relationship between the degree of lowering of blood pressure and inflammatory factors and the relationship between pulse pressure and inflammatory factors. Finally, we analyzed predictive factors in patients who received the protective benefit of candesartan. Results After 6 months of treatment, significant improvements from baseline values were observed in all patients in HMW-ADN and PAI-1 but not in Hs-CRP, VCAM-1 and U-8-OHdG. Multilinear regression analysis was performed to determine which factors could best predict changes in HMW-ADN and PAI-1. Changes in blood pressure were not significant predictors of changes in metabolic factors in all patients. We found that the group with baseline pulse pressure Conclusions Candesartan improved inflammatory parameters (HMW-ADN and PAI-1 in hypertensive patients with type 2 diabetes mellitus of long duration independent of blood pressure changes. Patients with pulse pressure Trial registration UMIN000007921

  17. Effects of candesartan in hypertensive patients with type 2 diabetes mellitus on inflammatory parameters and their relationship to pulse pressure.

    Science.gov (United States)

    Sakamoto, Masaya; Suzuki, Hirofumi; Hayashi, Takeshi; Iuchi, Hiroyuki; Isaka, Tsuyoshi; Sakamoto, Noriko; Kayama, Yosuke; Tojo, Katsuyoshi; Yoshimura, Michihiro; Utsunomiya, Kazunori

    2012-10-03

    Angiotensin receptor blockers (ARBs) are reported to provide direct protection to many organs by controlling inflammation and decreasing oxidant stress in patients without arteriosclerosis. This study aimed to evaluate (1) whether an ARB (candesartan) decreases values for inflammatory parameters in hypertensive patients with type 2 diabetes mellitus of long duration accompanied by arteriosclerosis and (2) whether there any predictors of which patients would receive the benefits of organ protection by candesartan. We administered candesartan therapy (12 mg daily) for 6 months and evaluated whether there was improvement in serum inflammatory parameters high molecular weight adiponectin (HMW-ADN), plasminogen activator inhibitor-1 (PAI-1), highly sensitive C-reactive protein (Hs-CRP), vascular cell adhesion molecule-1 (VCAM-1) in serum and urinary-8-hydroxydeoxyguanosine (U-8-OHdG). We then analyzed the relationship between the degree of lowering of blood pressure and inflammatory factors and the relationship between pulse pressure and inflammatory factors. Finally, we analyzed predictive factors in patients who received the protective benefit of candesartan. After 6 months of treatment, significant improvements from baseline values were observed in all patients in HMW-ADN and PAI-1 but not in Hs-CRP, VCAM-1 and U-8-OHdG. Multilinear regression analysis was performed to determine which factors could best predict changes in HMW-ADN and PAI-1. Changes in blood pressure were not significant predictors of changes in metabolic factors in all patients. We found that the group with baseline pulse pressure Candesartan improved inflammatory parameters (HMW-ADN and PAI-1) in hypertensive patients with type 2 diabetes mellitus of long duration independent of blood pressure changes. Patients with pulse pressure candesartan. UMIN000007921.

  18. 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.

  19. Respiratory pulse pressure variation fails to predict fluid responsiveness in acute respiratory distress syndrome.

    Science.gov (United States)

    Lakhal, Karim; Ehrmann, Stephan; Benzekri-Lefèvre, Dalila; Runge, Isabelle; Legras, Annick; Dequin, Pierre-François; Mercier, Emmanuelle; Wolff, Michel; Régnier, Bernard; Boulain, Thierry

    2011-01-01

    Fluid responsiveness prediction is of utmost interest during acute respiratory distress syndrome (ARDS), but the performance of respiratory pulse pressure variation (ΔRESPPP) has scarcely been reported. In patients with ARDS, the pathophysiology of ΔRESPPP may differ from that of healthy lungs because of low tidal volume (Vt), high respiratory rate, decreased lung and sometimes chest wall compliance, which increase alveolar and/or pleural pressure. We aimed to assess ΔRESPPP in a large ARDS population. Our study population of nonarrhythmic ARDS patients without inspiratory effort were considered responders if their cardiac output increased by >10% after 500-ml volume expansion. Among the 65 included patients (26 responders), the area under the receiver-operating curve (AUC) for ΔRESPPP was 0.75 (95% confidence interval (CI95): 0.62 to 0.85), and a best cutoff of 5% yielded positive and negative likelihood ratios of 4.8 (CI95: 3.6 to 6.2) and 0.32 (CI95: 0.1 to 0.8), respectively. Adjusting ΔRESPPP for Vt, airway driving pressure or respiratory variations in pulmonary artery occlusion pressure (ΔPAOP), a surrogate for pleural pressure variations, in 33 Swan-Ganz catheter carriers did not markedly improve its predictive performance. In patients with ΔPAOP above its median value (4 mmHg), AUC for ΔRESPPP was 1 (CI95: 0.73 to 1) as compared with 0.79 (CI95: 0.52 to 0.94) otherwise (P = 0.07). A 300-ml volume expansion induced a ≥ 2 mmHg increase of central venous pressure, suggesting a change in cardiac preload, in 40 patients, but none of the 28 of 40 nonresponders responded to an additional 200-ml volume expansion. During protective mechanical ventilation for early ARDS, partly because of insufficient changes in pleural pressure, ΔRESPPP performance was poor. Careful fluid challenges may be a safe alternative.

  20. Oscillometric measurement of arterial pulse pressure for patients supported by a rotary blood pump.

    Science.gov (United States)

    Yu, Yih-Choung; Peterson, Anna

    2015-01-01

    A computer model has been developed to evaluate the accuracy of an oscillometric method to measure the arterial pulse pressure from a patient with a rotary ventricular assist device (VAD). This computer model consists of three major components: the cardiovascular system, the HeartMate II VAD, and the operation of an automated cuff. Simulation was performed to mimic failure, recovery, and normal cardiac functions of a patient, supported by the HeartMate II VAD at different levels from minimum to maximum. The oscillating cuff pressure, simulating the air pressure of a deflecting cuff, was obtained from simulation under different conditions to test the accuracy of an oscillometric algorithm in determining the arterial pulse pressure. The algorithm was able to detect the systolic and diastolic arterial pressure with the error within ±2 mmHg in most cases, except the cases when ventricular suction, induced by the VAD, occurred. The results from this study suggested that the oscillometric algorithm is capable to accurately detect the arterial pulse pressure for a rotary VAD patient if the algorithm is properly tuned.

  1. 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 (<60 versus ≥60...

  2. Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices

    OpenAIRE

    Monnet, Xavier; Anguel, Nadia; Naudin, Brice; Jabot, Julien; Richard, Christian; Teboul, Jean-Louis

    2010-01-01

    Introduction We compared the ability of two devices estimating cardiac output from arterial pressure-curve analysis to track the changes in cardiac output measured with transpulmonary thermodilution induced by volume expansion and norepinephrine in sepsis patients. Methods In 80 patients with septic circulatory failure, we administered volume expansion (40 patients) or introduced/increased norepinephrine (40 patients). We measured the pulse contour-derived cardiac index (CI) provided by the P...

  3. HIGH BLOOD PRESSURE: DOES THIS CONCERN ME?

    CERN Document Server

    2007-01-01

    To find out, the Medical Service's nurses are organising A HIGH BLOOD PRESSURE SCREENING AND PREVENTION CAMPAIGN from Monday, 26th to Thursday, 29th March 2007 at the Infirmary - Building 57 - ground floor A blood pressure test, advice, information and, if necessary, referral for specialist medical treatment will be offered to any person working on the CERN site. High blood pressure is a stealth threat to health. So come and get your blood pressure checked.

  4. HIGH BLOOD PRESSURE: DOES THIS CONCERN ME?

    CERN Multimedia

    2007-01-01

    To find out, the Medical Service's nurses are organising A HIGH BLOOD PRESSURE SCREENING AND PREVENTION CAMPAIGN from Monday, 26th to Thursday, 29th March 2007 at the Infirmary - Building 57 - ground floor A blood pressure test, advice, information and, if necessary, referral for specialist medical treatment will be offered to any person working on the CERN site. High blood pressure is a silent threat to health. So come and get your blood pressure checked.

  5. Origin of the stabilization of the metastable tetragonal high-pressure phase in SrCuO{sub 2} thin films grown on SrTiO{sub 3} substrates by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mihailescu, C.N. [Nanotechnology Research Center and Department of Mechanical and Manufacturing Engineering, University of Cyprus, 75 Kallipoleos Av., PO Box 20537, 1678 Nicosia (Cyprus); National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., PO Box MG-36, 077125 Magurele (Romania); Pasuk, I. [National Institute of Materials Physics, RO-077125 Magurele (Romania); Straticiuc, M.; Nita, C.R.; Pantelica, D. [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), 30 Reactorului Street, P.O. Box MG-6, RO-077125 Magurele (Romania); Giapintzakis, J., E-mail: giapintz@ucy.ac.cy [Nanotechnology Research Center and Department of Mechanical and Manufacturing Engineering, University of Cyprus, 75 Kallipoleos Av., PO Box 20537, 1678 Nicosia (Cyprus)

    2014-11-30

    Highlights: • By tuning the substrate temperature one can obtain SrCuO{sub 2} films that exhibit both stable (orthorhombic) and metastable (tetragonal) phases in pure form as well as films composed of a mixture of tetragonal and orthorhombic phases. • SrCuO{sub 2} films exhibit a stoichiometry variation across the temperature range of the structural transformation. • The non-equilibrium nature of the growth process is the origin of the stabilization of the tetragonal (hp I) phase in SrCuO{sub 2} thin films grown on SrTiO{sub 3} substrates at low substrate temperatures. - Abstract: In this work we have systematically investigated the evolution of structure and stoichiometry in SrCuO{sub 2} films grown on TiO{sub 2}-terminated SrTiO{sub 3} substrates as a function of the substrate temperature. Depending on the growth temperature SrCuO{sub 2}/SrTiO{sub 3} films can exhibit either a pure tetragonal high-pressure phase, or a pure orthorhombic low-pressure phase, or a mixed phase. Our results indicate that at low substrate temperatures the non-equilibrium state of the growth process is responsible for the stabilization of the metastable tetragonal high-pressure structure in SrCuO{sub 2} thin films grown on ( 0 0 1) SrTiO{sub 3} substrates, whose lattice matches the metastable structure. In addition, at higher substrate temperatures thermodynamics become dominant over other factors and the SrCuO{sub 2} thin films are stabilized in the thermodynamically stable orthorhombic phase.

  6. 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.

  7. Diagnosis of High Blood Pressure

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  6. Prevention of High Blood Pressure

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  7. What Causes High Blood Pressure?

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  9. Living with High Blood Pressure

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  12. High-pressure study on some superconductors

    CERN Document Server

    Li, K Q; Yao, Y S; Che, G C; Zhao, Z X

    2002-01-01

    High-pressure study has played an important role in the investigation of conventional superconductors. Since the discovery of cuprate superconductors, high-pressure study has become even more important, especially as regards high-pressure synthesis and the effect of pressure. In this report, the new materials Ca-doped Pr-123, (Fe, Cu)-1212, and MgB sub 2 - a very new and interesting system synthesized under high pressure with good quality - will be discussed. Chemical inner pressure has been thought to explain the high T sub c of Ca-doped Pr-123. As another possibility, the replacement of the physical pressure effect by a chemical effect will be discussed.

  13. Plotting systolic, diastolic, and pulse pressure on a real time scale.

    Science.gov (United States)

    Velden, M; Wölk, C

    1990-11-01

    Since a valid non-invasive method for continuously measuring blood pressure is available for the psychophysiological laboratory, a procedure must be found for depicting blood pressure characteristics (systolic, diastolic, pulse pressure) on a real time scale, that is not simply from one heartbeat to the next. Values for blood pressure characteristics are actualized by heartbeats and thus occur at discrete points in time only, quite like values for heart rate. It is being assumed that the conditions for the blood pressure characteristics vary continuously, however, and that a value, actualized by a heartbeat, is representative for a time interval extending halfway before and after the point in time where it occurs. For computing a value for a real time interval it is proposed to weight the blood pressure values according to the amount of time their respective time intervals extend within the real time interval.

  14. High voltage pulsed cable design: a practical example

    Energy Technology Data Exchange (ETDEWEB)

    Kewish, R.W. Jr.; Boicourt, G.P.

    1979-01-01

    The design of optimum high voltage pulse cable is difficult because very little emperical data are available on performance in pulsed applications. This paper follows the design and testing of one high voltage pulse cable, 40/100 trigger cable. The design was based on an unproven theory and the impressive outcome lends support to the theory. The theory is outlined and it is shown that there exists an inductance which gives a cable of minimum size for a given maximum stress. Test results on cable manufactured according to the design are presented and compared with the test results on the cable that 40/100 replaces.

  15. Study on cathode high voltage pulse control in image intensifier

    Science.gov (United States)

    Yang, Ye; Yan, Bo; Ni, Xiao-bing; Zhi, Qiang; Li, Jun-guo; Yao, Ze; Deng, Guang-xu

    2016-03-01

    This paper briefly introduces the basic working principle of auto-gating power source. Due to the presence of noise in the circuit, the cathode pulse signal generated by the AD converter is unstable. In this paper, the circuit of the AD converter is adjusted to improve the instability of the cathode high voltage pulse signal, especially in the case of low light and high illumination to avoid the jitter of the pulse. The experiment was carried out. And it could guide the implementation of this part of the circuit.

  16. High stability breakdown of noble gases with femtosecond laser pulses.

    Science.gov (United States)

    Heins, A M; Guo, Chunlei

    2012-02-15

    In the past, laser-induced breakdown spectroscopy (LIBS) signals have been reported to have a stability independent of the pulse length in solids. In this Letter, we perform the first stability study of femtosecond LIBS in gases (to our best knowledge) and show a significant improvement in signal stability over those achieved with longer pulses. Our study shows that ultrashort-pulse LIBS has an intrinsically higher stability in gas compared to nanosecond-pulse LIBS because of a deterministic ionization process at work in the femtosecond pulse. Relative standard deviations below 1% are demonstrated and are likely only limited by our laser output fluctuations. This enhanced emission stability may open up possibilities for a range of applications, from monitoring rapid gas dynamics to high-quality broadband light sources.

  17. Ultrasonic level sensors for liquids under high pressure

    Science.gov (United States)

    Zuckerwar, A. J.; Mazel, D. S.; Hodges, D. Y.

    1986-01-01

    An ultrasonic level sensor of novel design continuously measures the level of a liquid subjected to a high pressure (up to about 40 MPa), as is sometimes required for the effective transfer of the liquid. The sensor operates as a composite resonator fabricated from a standard high-pressure plug. A flat-bottom hole is machined into the plug along its center line. An ultrasonic transducer is bonded rigidly to the interior surface of the bottom wall, while the exterior surface is in contact with the liquid. Although the bottom wall is designed to satisfy the pressure code, it is still sufficiently thin to permit ready excitation of the axisymmetric plate modes of vibration. The liquid level is measured by a conventional pulse-echo technique. A prototype sensor was tested successfully in a 2300-l water vessel at pressures up to about 37 MPa. A spectral analysis of the transmitted pulse reveals that the flexural, extensional, thickness-shear, and radial plate modes are excited into vibration, but none of these appears to be significantly affected by the pressurization of the liquid.

  18. 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....

  19. High pressure synthesis gas conversion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    The purpose of this research project is to build and test a high pressure fermentation system for the production of ethanol from synthesis gas. The fermenters, pumps, controls, and analytical system were procured or fabricated and assembled in our laboratory. This system was then used to determine the effects of high pressure on growth and ethanol production by Clostridium ljungdahlii. The limits of cell concentration and mass transport relationships were found in CSTR and immobilized cell reactors (ICR). The minimum retention times and reactor volumes were found for ethanol production in these reactors. A maximum operating pressure of 150 psig has been shown to be possible for C. ljungdahlli with the medium of Phillips et al. This medium was developed for atmospheric pressure operation in the CSTR to yield maximum ethanol concentrations and thus is not best for operation at elevated pressures. It is recommended that a medium development study be performed for C. ljungdahlii at increased pressure. Cell concentration, gas conversion and product concentration profiles were presented for C. ljungdahlii as a function of gas flow rate, the variable which affects bacterium performance the most. This pressure was chosen as a representative pressure over the 0--150 psig operating pressure range for the bacterium. Increased pressure negatively affected ethanol productivity probably due to the fact that medium composition was designed for atmospheric pressure operation. Medium development at increased pressure is necessary for high pressure development of the system.

  20. A high voltage pulsed power supply for capillary discharge waveguide applications

    Science.gov (United States)

    Abuazoum, S.; Wiggins, S. M.; Issac, R. C.; Welsh, G. H.; Vieux, G.; Ganciu, M.; Jaroszynski, D. A.

    2011-06-01

    We present an all solid-state, high voltage pulsed power supply for inducing stable plasma formation (density ˜1018 cm-3) in gas-filled capillary discharge waveguides. The pulser (pulse duration of 1 μs) is based on transistor switching and wound transmission line transformer technology. For a capillary of length 40 mm and diameter 265 μm and gas backing pressure of 100 mbar, a fast voltage pulse risetime of 95 ns initiates breakdown at 13 kV along the capillary. A peak current of ˜280 A indicates near complete ionization, and the r.m.s. temporal jitter in the current pulse is only 4 ns. Temporally stable plasma formation is crucial for deploying capillary waveguides as plasma channels in laser-plasma interaction experiments, such as the laser wakefield accelerator.

  1. Spectral analysis of intraocular pressure pulse wave in ocular hypertensive and primary open angle glaucoma patients

    Directory of Open Access Journals (Sweden)

    Marija M Bozic

    2016-01-01

    Full Text Available Context: In attempt to find an alternative way to determine conversion from ocular hypertension to primary open angle glaucoma (POAG (besides visual field and optic disc changes, we analyzed intraocular pressure (IOP pulse wave in spectral domain. Aims: The aim of this study was to test the potential differences in spectral content of IOP pulse wave between ocular hypertension and POAG patients, which could indicate conversion. Settings and Design: Cross-sectional study designed to test the differences in the spectral content of pressure pulse wave between nontreated ocular hypertensive and nontreated, freshly diagnosed POAG patients. Methods: The total of 40 eyes of 40 subjects was included: 20 previously untreated ocular hypertensive patients, and 20 previously untreated POAG patients. Continuous IOP measuring gained by dynamic contour tonometry was submitted to fast Fourier transform signal analysis and further statistical data processing. Statistics Analysis Used: Ocular and systemic characteristics of the tested subjects were compared by analysis of variance appropriate for this study design. A P < 0.05 was considered to be statistically significant. Results: Higher spectral components of the IOP pulse wave was discerned up to the fifth harmonic in both of the tested groups. No statistically significant differences were found in any of the tested harmonic amplitudes. Conclusions: There are no differences in the spectral content of IOP pulse wave between ocular hypertensive and primary open angle glaucoma patients which could be indicative for conversion.

  2. Nozzle Exit Over-Pressure and Vortex Ring Interaction in a Fully-Pulsed Jet

    Science.gov (United States)

    Krueger, Paul S.; Gharib, Morteza

    2002-11-01

    Vortex rings formed by a starting jets will stop entraining circulation and pinch off from their generating or "trailing" jet for sufficiently large piston stroke length to jet diameter ratios (L/D) [Gharib et. al., JFM, 1998]. Recent work by the authors has demonstrated that the leading vortex ring contributes more impulse per unit L/D than does the trailing jet, highlighting the significance of vortex ring pinch off for propulsive applications. The impulse advantage of the leading vortex ring is provided by nozzle exit over-pressure resulting from the acceleration of ambient fluid during ring formation. The present work extends these single-pulse results to a periodic series of starting jets, i.e., a fully-pulsed jet. Measurements were made of the time-averaged thrust of fully-pulsed jets generated using a piston-cylinder mechanism for 2 < L/D < 6 and a range of pulsing frequencies. The results indicate that vortex ring formation provides substantial nozzle exit over-pressure (and hence, thrust benefit) in the pulsed case as well, but the benefit tends to diminish with increasing frequency. Various vortex ring interactions contribute to this trend.

  3. High Precision Pressure Measurement with a Funnel

    Science.gov (United States)

    Lopez-Arias, T.; Gratton, L. M.; Oss, S.

    2008-01-01

    A simple experimental device for high precision differential pressure measurements is presented. Its working mechanism recalls that of a hydraulic press, where pressure is supplied by insufflating air under a funnel. As an application, we measure air pressure inside a soap bubble. The soap bubble is inflated and connected to a funnel which is…

  4. Experimental and numerical analysis of pressure pulses characteristics in a Francis turbine with partial load

    Energy Technology Data Exchange (ETDEWEB)

    Yexiang, X; Zhengwei, W; Zongguo, Y; Jin, Z, E-mail: xiaoyex@mail.tsinghua.edu.c [State Key Laboratory of Hydroscience and Engineering and Department of Thermal Engineering, Tsinghua University Beijing, 100084 (China)

    2010-08-15

    This study experimentally and numerically investigates the pressure pulses characteristics and unsteady flow behavior in a Francis turbine with partial load. Unsteady wall pressure measurements with partial load condition are performs to investigate thoroughly pressure fields in the spiral case, runner head cover and straight draft tube dynamically. The unsteady Reynolds- averaged Navier-Stokes equations with the k-{omega}based SST turbulence model were used to model the unsteady flow within the entire flow passage of the Francis turbine. The dominate frequency of the predicted pressure pulses at runner inlet agree with the experimental results in the head cover. The influence of the blade passing frequency causes the simulated peak-to-peak amplitudes in the runner inlet to be larger than in the head cover. The measured and predicted pressure pulses at different positions along the runner are comparable. The predicted pressure fluctuations in the draft tube agree well with the experimental results. However the peak-to-peak amplitudes in the spiral case are not as well predicted so the calculation domain and the inlet boundary conditions need to be improved. At the most unstable operating condition, the pulse in the flow passage are due to the rotor-stator interference (RSI) between the runner and the guide vanes, the blade channel vortex in the runner blade passage and the vortex rope in the draft tube. The unsteady flow patterns in the turbine, including the blade channel vortex in the runner and the helical vortex rope in the draft tube, are classified numerically.

  5. Experimental and numerical analysis of pressure pulses characteristics in a Francis turbine with partial load

    Science.gov (United States)

    Yexiang, X.; Zhengwei, W.; Zongguo, Y.; Jin, Z.

    2010-08-01

    This study experimentally and numerically investigates the pressure pulses characteristics and unsteady flow behavior in a Francis turbine with partial load. Unsteady wall pressure measurements with partial load condition are performs to investigate thoroughly pressure fields in the spiral case, runner head cover and straight draft tube dynamically. The unsteady Reynolds- averaged Navier-Stokes equations with the k-ωbased SST turbulence model were used to model the unsteady flow within the entire flow passage of the Francis turbine. The dominate frequency of the predicted pressure pulses at runner inlet agree with the experimental results in the head cover. The influence of the blade passing frequency causes the simulated peak-to-peak amplitudes in the runner inlet to be larger than in the head cover. The measured and predicted pressure pulses at different positions along the runner are comparable. The predicted pressure fluctuations in the draft tube agree well with the experimental results. However the peak-to-peak amplitudes in the spiral case are not as well predicted so the calculation domain and the inlet boundary conditions need to be improved. At the most unstable operating condition, the pulse in the flow passage are due to the rotor-stator interference (RSI) between the runner and the guide vanes, the blade channel vortex in the runner blade passage and the vortex rope in the draft tube. The unsteady flow patterns in the turbine, including the blade channel vortex in the runner and the helical vortex rope in the draft tube, are classified numerically.

  6. Estudio de ignitores de pulso(s superpuesto(s para el encendido de lámparas de vapor de sodio de alta presión;Estudy of ignitors of superimposed pulse(s for the starting of the high pressure sodium lamps

    Directory of Open Access Journals (Sweden)

    Alexander Fernández- Correa; et al.

    2011-06-01

    Full Text Available En este trabajo se compara el comportamiento de los ignitores serie y paralelo para lámparas de descarga de alta intensidad, se realiza una revisión de los métodos que existen en la literatura para el encendido de las mismas, cumpliendo con los requerimientos que establecen la norma Americana o la norma Europea, se analizan las especificidades que debe presentar el pulso de ignición, tales como el tiempo de subida, el ancho , la tasa de repetición y la posición que debe presentar el mismo con respecto a la tensión de la red, ya que ambas normas presentan poca información en lo que respecta al proceso de ignición de las lámparas de alta intensidad y difieren en algunos parámetros una de la otra. Se evalúa además la influencia de los componentes del circuito sobre los parámetros del pulso y además se evalúan los efectos que provocan las capacitancias parásitas sobre el pulso de ignición de la lámpara.In this work we compare the behavior of serial and parallel ignitors for discharge lamps, high intensity, we review the methods that exist in the literature for the ignition of the same, meeting the requirements of the standard American or European standard, we analyze the specifics to be presented by the pulse of ignition, such as rise time, width, repetition rate and the position must submit the same with respect to the supply voltage, since both rules have little information regarding the process of ignition of high intensity lamps in some parameters differ from one another. It also evaluates the influence of circuit components on the pulse parameters and also evaluated the effects of parasitic capacitances cause the pulse lamp ignition.

  7. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... blood pressure, you may need to restrict your sodium intake even more. Your health care provider may recommend the Dietary Approaches to ... heart healthy and low in fat, cholesterol, and salt. The DASH eating plan is ... Eating Your health care provider also may recommend heart-healthy eating, ...

  8. Diagnosis of High Blood Pressure

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    Full Text Available ... Related Topics Atherosclerosis DASH Eating Plan Overweight and Obesity Smoking and Your Heart Stroke Send a link ... are consistently higher than 120/80 mmHg. Your child’s blood pressure numbers are outside average numbers for ...

  9. Diagnosis of High Blood Pressure

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    Full Text Available ... and Strategic Vision Leadership Scientific Divisions Operations and Administration Advisory Committees Budget and Legislative Information Jobs and ... With DASH My Blood Pressure Wallet Card Other Resources Cigarette and Tobacco Facts (National Institute on Drug ... OIG USA.gov

  10. Diagnosis of High Blood Pressure

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    Full Text Available ... blood pressure. The DASH eating plan focuses on fruits, vegetables, whole grains, and other foods that are heart ... heart-healthy eating, which should include: Whole grains Fruits, such as apples, bananas, oranges, pears, and prunes Vegetables, such as broccoli, cabbage, and carrots Legumes, such ...

  11. Diagnosis of High Blood Pressure

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    Full Text Available ... lead to cognitive changes. Signs and symptoms include memory loss, difficulty finding words, and losing focus during ... are consistently higher than 120/80 mmHg. Your child’s blood pressure numbers are outside average numbers for ...

  12. Diagnosis of High Blood Pressure

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    Full Text Available ... bleed. Signs and symptoms include vision changes or blindness. Heart Attack : When the flow of oxygen-rich ... are consistently higher than 120/80 mmHg. Your child’s blood pressure numbers are outside average numbers for ...

  13. Diagnosis of High Blood Pressure

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    Full Text Available ... healthy diet. Be physically active. Maintain a healthy weight. Limit alcohol intake. Other lifestyle changes can improve your overall health, such as: If you smoke , quit. Get plenty of sleep. Drink more water. Medicines Take all blood pressure ...

  14. Diagnosis of High Blood Pressure

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    Full Text Available ... to develop your treatment plan. Some people have “white coat hypertension.” This happens when blood pressure readings ... which can occur during the medical appointment, causes white coat hypertension. Treatment Based on your diagnosis, health ...

  15. Diagnosis of High Blood Pressure

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    Full Text Available ... Health Topics Health Topics A-Z Clinical Trials Publications and Resources Health Education and Awareness The Science ... are consistently higher than 120/80 mmHg. Your child’s blood pressure numbers are outside average numbers for ...

  16. Diagnosis of High Blood Pressure

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    Full Text Available ... are heart healthy. Limiting Sodium and Salt A low-sodium diet can help you manage your blood pressure. ... lower in salt and sodium. Try to use low-sodium and “no added salt” foods and seasonings at ...

  17. Diagnosis of High Blood Pressure

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    Full Text Available ... other health problems. If you’re overweight or obese, try to lose weight. A loss of just 3 to 5 percent can lower ... risk for health problems. Greater amounts of weight loss can improve blood pressure readings, lower ... to maintain good health. A useful measure of overweight and obesity is body mass index (BMI). BMI measures your ...

  18. Blood pressure, pulse rate, and rhythm measurement using ionic polymer-metal composite sensors

    Science.gov (United States)

    Keshavarzi, Amid; Shahinpoor, Mohsen; Kim, Kwang J.; Lantz, Jeffrey W.

    1999-05-01

    The need for more enhanced blood pressure (BP), pulse rate and rhythm senors has given rise to the possibility of using ionic polymer-metal composites (IPMCs) sensors. In this study we propose to use the IPMC sensors to measure systolic and diastolic BP, pulse rate and rhythm. The proposed IPMC sensors take advantage of the endo-ionic mobility within the polymer- metal composite by converting normal and shear load inputs into an induced voltage output across the thickness of the IPMC sensor. The fabricated IPMC sensors are suitable to be installed on the inner surface of a cuff and, therefore, both systolic and diastolic BP, pulse rate, and rhythm can be measured. An added benefit is the ability of measuring 'pulse rhythm' which give a more amplified look at heart irregularities which a typical pulse rate sensor is unable to show. Our data shows IPMC sensors can produce consistent and reliable BP readings, pulse rate, and rhythm. Typically, a linear relationship between applied maximum load and induced maximum voltage was obtained. This result can be easily translated into good BP reading.

  19. High-Precision Spectroscopy with Counterpropagating Femtosecond Pulses

    Science.gov (United States)

    Barmes, Itan; Witte, Stefan; Eikema, Kjeld S. E.

    2013-07-01

    An experimental realization of high-precision direct frequency comb spectroscopy using counterpropagating femtosecond pulses on two-photon atomic transitions is presented. The Doppler broadened background signal, hampering precision spectroscopy with ultrashort pulses, is effectively eliminated with a simple pulse shaping method. As a result, all four 5S-7S two-photon transitions in a rubidium vapor are determined with both statistical and systematic uncertainties below 10-11, which is an order of magnitude better than previous experiments on these transitions.

  20. Pulse generator using transistors and silicon controlled rectifiers produces high current pulses with fast rise and fall times

    Science.gov (United States)

    Woolfson, M. G.

    1966-01-01

    Electrical pulse generator uses power transistors and silicon controlled rectifiers for producing a high current pulse having fast rise and fall times. At quiescent conditions, the standby power consumption of the circuit is equal to zero.