Sample records for bottom-hole pressure

  1. Parameter estimation for estimation of bottom hole pressure during drilling.


    Vea, Hans Kristian


    In this thesis we examine four bottom hole pressure estimators based on adaptive estimation of the friction pressure for the drill string and the annulus. Knowledge about the bottom hole pressure is crucial to achieve security and commercial objectives. Bottom hole pressure measurements transmitted by mud pulse telemetry have limited bandwidth and it is common to use additional models to estimate the bottom hole pressure when measurements are unavailable. The motivation for an adaptive approa...

  2. Better well control through safe drilling margin identification, influx analysis and direct bottom hole pressure control method for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Veeningen, Daan [National Oilwell Varco IntelliServ (NOV), Houston, TX (United States)


    Currently, well control events are almost exclusively detected by using surface measurements. Measuring a volume increase in the 'closed loop' mud circulation system; a standpipe pressure decrease; or changes in a variety of drilling parameters provide indicators of a kick. Especially in deep water, where the riser comprises a substantial section of the well bore, early kick detection is paramount for limiting the severity of a well bore influx and improve the ability to regain well control. While downhole data is presently available from downhole tools nearby the bit, available data rates are sparse as mud pulse telemetry bandwidth is limited and well bore measurements compete with transmission of other subsurface data. Further, data transfer is one-directional, latency is significant and conditions along the string are unknown. High-bandwidth downhole data transmission system, via a wired or networked drill string system, has the unique capability to acquire real-time pressure and temperature measurement at a number of locations along the drill string. This system provides high-resolution downhole data available at very high speed, eliminating latency and restrictions that typically limit the availability of downhole data. The paper describes well control opportunities for deep water operations through the use of downhole data independent from surface measurements. First, the networked drill string provides efficient ways to identify pore pressure, fracture gradient, and true mud weight that comprise the safe drilling margin. Second, the independent measurement capability provides early kick detection and improved ability to analyze an influx even with a heterogeneous mud column through distributed along-string annular pressure measurements. Third, a methodology is proposed for a direct measurement method using downhole real-time pressure for maintaining constant bottom hole pressure during well kills in deep water. (author)

  3. Laser bottom hole assembly (United States)

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O


    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  4. Reservoir Characterization and CO2 Plume Migration Modeling Based on Bottom-hole Pressure Data: An Example from the AEP Mountaineer Geological Storage Project (United States)

    Mishra, Srikanta; Kelley, Mark; Oruganti, YagnaDeepika; Bhattacharya, Indra; Spitznogle, Gary


    -invasive strategy for inferring the extent of the CO2 plume from the analysis of pressure monitoring data. Application of this methodology to the Rose Run data indicates a two-zone permeability model for the undisturbed formation, as well as an estimate of CO2 front movement over time. For reservoir modeling, a 2-D radial-cylindrical model based on "average" conditions in the study area was developed from integration of well-log and seismic data. STOMP-CO2 simulations were carried out to calibrate the observed pressure response using a trial-and-error procedure. This involved varying: (1) permeability near the injection well, (2) permeability of the far-field region, and (3) relative permeability model coefficients. Non-unique combinations of these parameters were found to produce similar pressure match, but different estimates of plume migration. Excellent matches were obtained for the bottom-hole pressures both at the injection well and the monitoring well using a two-zone permeability model, which corroborates the transient pressure analysis results. Estimates of radial plume migration, using the calibrated model, also agree well with those from the front tracking method described earlier.

  5. Development of Radar Navigation and Radio Data Transmission for Microhole Coiled Tubing Bottom Hole Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Larry G. Stolarczyk; Gerald L. Stolarczyk; Larry Icerman; John Howard; Hooman Tehrani


    This Final Technical Report summarizes the research and development (R&D) work performed by Stolar Research Corporation (Stolar) under U.S. Department of Energy (DOE) Contract Number DE-FC26-04NT15477. This work involved the development of radar navigation and radio data transmission systems for integration with microhole coiled tubing bottom hole assemblies. Under this contract, Stolar designed, fabricated, and laboratory and field tested two advanced technologies of importance to the future growth of the U.S. oil and gas industry: (1) real-time measurement-while-drilling (MWD) for guidance and navigation of coiled tubing drilling in hydrocarbon reservoirs and (2) two-way inductive radio data transmission on coiled tubing for real-time, subsurface-to-surface data transmission. The operating specifications for these technologies are compatible with 3.5-inch boreholes drilled to a true vertical depth (TVD) of 5,000 feet, which is typical of coiled tubing drilling applications. These two technologies (i.e., the Stolar Data Transmission System and Drill String Radar) were developed into pre-commercial prototypes and tested successfully in simulated coiled tubing drilling conditions. Integration of these two technologies provides a real-time geosteering capability with extremely quick response times. Stolar is conducting additional work required to transition the Drill String Radar into a true commercial product. The results of this advanced development work should be an important step in the expanded commercialization of advanced coiled tubing microhole drilling equipment for use in U.S. hydrocarbon reservoirs.

  6. Visualization and verification of how static and dynamic drilling parameters contribute to the bottom hole pressure while drilling a well


    Vaaland, Gisle


    Even with all the talk about finding an alternative fuel, the demand for fossil fuel will not decrease for years to come. As the major oilfields are depleting and aging, this demand forces wells to be drilled in more hostile environment both with regards to location, where wells have to be drilled at deeper water depths, and the environment experienced in the reservoirs that allow for lesser margin of error. Such advanced and difficult wells are forcing the use of more advanced te...

  7. Oil Well Bottom Hole Locations, This GIS data set was produced as a general reference for the Department of Natural Resources, the oil and gas industry, environmental and regulatory agencies, landowners, and the public., Published in 2007, 1:24000 (1in=2000ft) scale, Louisiana State University. (United States)

    NSGIC GIS Inventory (aka Ramona) — This Oil Well Bottom Hole Locations dataset, published at 1:24000 (1in=2000ft) scale as of 2007. It is described as 'This GIS data set was produced as a general...

  8. Dynamical analysis of high-pressure supercritical carbon dioxide jet in well drilling

    Institute of Scientific and Technical Information of China (English)

    DU Yu-kun; WANG Rui-he; NI Hong-jian; HUANG Zhi-yuan; LI Mu-kun


    This paper presents the design of an experimental setup and mathematical and physical models to determine the dynamical characteristics of the high-pressure supercritical carbon dioxide (SC-CO2) jet with a highly potential applications in the well drilling.The effects of three major factors on the wellbore dynamical characteristics of the high-pressure SC-CO2 jet,i.e.,the nozzle diameter,the standoff distance and the jet pressure are determined.It is indicated that the pressure of CO2 reduces severely in the SC-CO2 jet impact process.It is also found that the bottom-hole pressure and the temperature increase as the nozzle diameter increases but decrease with the increase of the standoff distance.The higher the jet pressure at the wellbore inlet is,the higher the pressure and the lower the temperature at the bottom-hole will be.

  9. Simulation and modeling of pressure pulse propagation in fluids inside drill strings


    Namuq, Mohammed Ali


    Modern bottom-hole assemblies are equipped with various sensors which measure the geological and directional information of the borehole while drilling. It is very crucial to get the measured downhole information to the surface in real time in order to be able to monitor, steer and optimize the drilling process while drilling. The transmission of the information to the surface is most commonly carried out by coded pressure pulses (the technology called mud pulse telemetry) which propagate thr...

  10. Development of computational tool to interpret real time Pd (Pressure While Drilling) data; Desenvolvimento de ferramenta computacional interpretadora de dados de PWD (Pressure While Drilling) em tempo real

    Energy Technology Data Exchange (ETDEWEB)

    Gandelman, Roni Abensur; Waldmann, Alex Tadeu de Almeida; Martins, Andre Leibsohn [Centro de Pesquisas da Petrobras (CENPES). Gerencia de Tecnologia de Engenharia de Poco (Brazil)], e-mails:,,; Teixeira, Gleber Tacio; Aragao, Atila Fernando Lima [E and P Servicos. Gerencia de Servicos de Poco (Brazil)], e-mail:,; Rezende, Mauricio Seiji; Kern, Eduardo; Maliska Junior, Clovis [Engineering Simulation and Scientific Software (ESSS), (Brazil)], e-mails:,,


    Drilling offshore oil wells is a very expensive and complex process, in which all the efforts must be taken to keep the annular pressure between a minimum pressure (pore pressure) and a maximum pressure (fracture pressure) which define the operational window limits. Several phenomena impact the bottom hole annular pressures, such as: ineffective hole cleaning, gel breaking when circulation is resumed, drill string movement (surge and swab), trips, pills displacement, kicks, etc. The correct interpretation of pressure while drilling (PWD) data is a very powerful toll to identify and prevent these phenomena. Nowadays, an expert monitors bottom hole pressures data and identifies undesirable events. The main goal of this project is the development of a computational tool to monitor pressure (and mud logging) data in real time to identify the causes of abnormal pressure variations, helping the operators to take decisions rapidly. Besides that, the tool allows the user to handle PWD data in a flexible architecture. This flexibility allows the incorporation of new methods of events identification as they are developed. The ultimate goals is to obtain a tool which serves both for the key study of the problems and physical, specific phenomena found during drilling, both for real-time monitoring to assist professionals involved in the process. (author)


    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-ying; LIU Yong-wang; XU Yi-ji; REN Jian-hua


    The high speed fluid jet for directly or indirectly breaking rock is one of the most effective ways to improve the deep penetration rate. In order to maximize the efficiency of energy use, the flow characteristics of different combinations of high pressure jet nozzles are analyzed through numerical simulations. According to the velocity vectors at the bottom and the bottom hole pressure diagram, the effects of the high pressure nozzle combinations on the flow structure and the penetration rate are analyzed. It is shown that the combination of three vertical edge nozzles is very efficient, but inefficient in cleaning the bottom hole and eroding the wall.The jet velocity is 400 m/s and the radius is 5 mm, with a center nozzle added, the problem can be solved, but the high-pressure fluid displacement would increase. The center nozzle's jet velocity is 200 m/s and the radius is 8 mm, the combination of two vertical edge nozzles and a center tilt nozzle or that of a vertical edge nozzle and a center tilt nozzle would provide a flow structure favorable for drilling. The angle of inclination is 10°. To take advantage of high pressure jet energy to improve the efficiency of drilling, it is important to select a suitable nozzle combination according real conditions.

  12. Ultrasonic level sensors for liquids under high pressure (United States)

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


    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.

  13. Application of fine managed pressure drilling technique in complex wells with both blowout and lost circulation risks

    Directory of Open Access Journals (Sweden)

    Ling Yan


    Full Text Available Fractured carbonate reservoirs are susceptible to blowout and lost circulation during drilling, which not only restricts drilling speed, but also poses big threat to well control. Moreover, there are few technical means available to reconstruct pressure balance in the borehole. Accordingly, the fine managed pressure drilling was used in the drilling of Well GS19 in the Qixia Formation with super-high pressure and narrow density window, which is a success: ① back pressure in the annular spaces will be adjusted to maintain a slightly over-balanced bottom-hole hydraulic pressure, and fluid level in the circulation tank will be kept in a slight dropping state to ensure that natural gas in the formation would not invade into the borehole in a massive volume; ② inlet drilling fluid density will be controlled at around 2.35 g/cm3, back pressures in the annular be maintained at 2–5 MPa, and bottom-hole pressure equivalent circulation density be controlled at 2.46–2.52 g/cm3; ③ during managed pressure drilling operations, if wellhead pressure exceeds or expects to exceed 7 MPa, semi-blind rams will be closed. Fluids will pass through the choke manifold of the rig to the choke manifold specifically for pressure control before entering gas/liquid separators to discharge gas; ④ during tripping back pressure will be kept at less than 5 MPa, volume of injected drilling fluid will be higher than the theoretical volume during tripping out, whereas the volume of returned drilling fluid will be higher than the theoretical volume during the out-tripping. This technique has been applied successfully in the drilling of the Qixia Formation, Liangshan Formation and Longmaxi Formation with a total footage of 216.60 m, as a good attempt in complicated wells with both blowout and lost circulation risks, which can provide valuable experiences and guidance for handling similar complexities in the future.

  14. Analytical modeling of pressure transient behavior for coalbed methane transport in anisotropic media (United States)

    Wang, Lei; Wang, Xiaodong


    Resulting from the nature of anisotropy of coal media, it is a meaningful work to evaluate pressure transient behavior and flow characteristics within coals. In this article, a complete analytical model called the elliptical flow model is established by combining the theory of elliptical flow in anisotropic media and Fick's laws about the diffusion of coalbed methane. To investigate pressure transient behavior, analytical solutions were first obtained through introducing a series of special functions (Mathieu functions), which are extremely complex and are hard to calculate. Thus, a computer program was developed to establish type curves, on which the effects of the parameters, including anisotropy coefficient, storage coefficient, transfer coefficient and rate constant, were analyzed in detail. Calculative results show that the existence of anisotropy would cause great pressure depletion. To validate new analytical solutions, previous results were used to compare with the new results. It is found that a better agreement between the solutions obtained in this work and the literature was achieved. Finally, a case study is used to explain the effects of the parameters, including rock total compressibility coefficient, coal medium porosity and anisotropic permeability, sorption time constant, Langmuir volume and fluid viscosity, on bottom-hole pressure behavior. It is necessary to coordinate these parameters so as to reduce the pressure depletion.

  15. Analytical modeling of pressure transient behavior for coalbed methane transport in anisotropic media

    International Nuclear Information System (INIS)

    Resulting from the nature of anisotropy of coal media, it is a meaningful work to evaluate pressure transient behavior and flow characteristics within coals. In this article, a complete analytical model called the elliptical flow model is established by combining the theory of elliptical flow in anisotropic media and Fick's laws about the diffusion of coalbed methane. To investigate pressure transient behavior, analytical solutions were first obtained through introducing a series of special functions (Mathieu functions), which are extremely complex and are hard to calculate. Thus, a computer program was developed to establish type curves, on which the effects of the parameters, including anisotropy coefficient, storage coefficient, transfer coefficient and rate constant, were analyzed in detail. Calculative results show that the existence of anisotropy would cause great pressure depletion. To validate new analytical solutions, previous results were used to compare with the new results. It is found that a better agreement between the solutions obtained in this work and the literature was achieved. Finally, a case study is used to explain the effects of the parameters, including rock total compressibility coefficient, coal medium porosity and anisotropic permeability, sorption time constant, Langmuir volume and fluid viscosity, on bottom-hole pressure behavior. It is necessary to coordinate these parameters so as to reduce the pressure depletion. (paper)

  16. Blood pressure (United States)

    ... the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart contracts, which ... as it relaxes, which is called diastole. Normal blood pressure is considered to be a systolic blood pressure ...

  17. Effect of Matrix-Wellbore Flow and Porosity on Pressure Transient Response in Shale Formation Modeling by Dual Porosity and Dual Permeability System

    Directory of Open Access Journals (Sweden)

    Daolun Li


    Full Text Available A mathematical dual porosity and dual permeability numerical model based on perpendicular bisection (PEBI grid is developed to describe gas flow behaviors in shale-gas reservoirs by incorporating slippage corrected permeability and adsorbed gas effect. Parametric studies are conducted for a horizontal well with multiple infinite conductivity hydraulic fractures in shale-gas reservoir to investigate effect of matrix-wellbore flow, natural fracture porosity, and matrix porosity. We find that the ratio of fracture permeability to matrix permeability approximately decides the bottom hole pressure (BHP error caused by omitting the flow between matrix and wellbore and that the effect of matrix porosity on BHP is related to adsorption gas content. When adsorbed gas accounts for large proportion of the total gas storage in shale formation, matrix porosity only has a very small effect on BHP. Otherwise, it has obvious influence. This paper can help us understand the complex pressure transient response due to existence of the adsorbed gas and help petroleum engineers to interpret the field data better.

  18. Pressure Sores (United States)

    ... pressure sore include the following: Thick yellow or green pus A bad smell from the sore Redness ... spots, color changes or other signs of sores. Pay special attention to the pressure points where sores ...

  19. Pressure ulcers. (United States)

    O'Byrne, Deborah


    My nursing experience is in acute care. Acute medical nurses are well placed to assess skin integrity, identify patients at risk of pressure ulcer development, and commence appropriate interventions to prevent or treat pressure ulcers. PMID:27073966

  20. Peer Pressure (United States)

    ... How Can I Help a Friend Who Cuts? Peer Pressure KidsHealth > For Teens > Peer Pressure Print A A A Text Size What's in ... She'd just had a big dose of peer pressure. Who Are Your Peers? When you were a ...

  1. 智能电控存储式油井分层测压仪研制%Stratified Pressure Instrument Development for Intelligent Electronic-controlled Oilwell

    Institute of Scientific and Technical Information of China (English)

    刘伟; 徐德奎; 姜春雷


    Basing on developing Annular technology, a smart and stratified pressure instrument for electroniccontrolled oilwell was developed. Of the instrument consisting of control modules for automatic setting, release and drive, and that for pressure measurement and host ground controller, the ground-controlled releasing motor can set the supporting arm of pressure instrument at detent mechanism of the bottom-hole regulator, and the control module for automatic setting and release can drive the underground motor to implement the setting and releasing operation of pressure instruments, and its testing module can record both single-layer static pressure and flowing pressure in the oilwell.%在研制过环空的基础上,开发智能电控存储油井分层测压仪.该测压仪主要由井下自动坐封、解封控制及驱动模块、测压仪丢手控制及驱动模块、压力测试模块、地面控制主机等部分构成.地面控制丢手电机使仪器定位支臂支承在配产器定位机构上;自动坐封、解封控制及驱动模块控制留在井下的坐封电机,实现测压仪坐封、解封,压力计测试模块记录油井单层静压和流压.

  2. Analytical solution of geological carbon sequestration under constant pressure injection into a horizontal radial reservoir (United States)

    Jhang, R.; Liou, T.


    Carbon capture and sequestration (CCS) is believed to be an economically feasible technology to mitigate global warming by capturing carbon dioxide (CO2), the major component of greenhouse gases, from the atmosphere and injecting it into deep geological formations.Several mechanisms can help trap CO2 in the pore space of a geological reservoir, stratigraphic and structural trapping, hydrodynamic trapping, and geochemical trapping.Besides these trapping mechanisms, another important issue that deserves careful attention is the risk of CO2 leakage. The common ';constant injection rate' scenario may induce high pressure buildup that will endanger the mechanical integrity as well as the sealing capability of the cap rock. Instead of injecting CO2 at a constant mass rate, CO2 can be injected into the reservoir by fixing the pressure (usually the bottom-hole pressure) in the injection borehole. By doing so, the inevitable pressure buildup associated with the constant injection scheme can be completely eliminated in the constant pressure injection scheme. In this paper, a semi-analytical solution for CO2 injection with constant pressure was developed. For simplicity, structural and geochemical trapping mechanisms were not considered. Therefore, a horizontal reservoir with infinite radial extent was considered. Prior to injection, the reservoir is fully saturated with the formation brine. It is assumed that CO2 does not mix with brine such that a sharp interface is formed once CO2 invades the brine-saturated pores. Because of the density difference between CO2 and brine, CO2 resides above the interface. Additional assumptions were also made when building up the brine and CO2 mass balance equations: (1) both of the fluids and the geological formations are incompressible, (2) capillary pressure is neglected, (3)there is no fluid flow in the vertical direction, and the horizontal flow satisfies the Darcy's law.In order to solve for the height of brine-CO2 interface, the two

  3. Case studies of the application of enhanced steel alloys for bottom hole assembly components for sour service conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Alvaro [Nov Grant Prideco, Navasota (United States); Moura, Carlos [ASPEN Assesoria Tecnica e Comercial, Cascavel, PR (Brazil); Johnson, Charles; Landriault, Alain [Weatherford Canda Partnership, Calgary, AB (Canada)


    The new more modern drilling programs require the drill string to travel across sour formations in order to reach the hydrocarbon reservoirs. Traditional materials have been employed in the manufacture of HWDP components along with basic heat treatment processes. Standard HWDP tools have started to show their operational as well as environmental limitations when subjected to sour service applications. The advanced, more complex drilling programs require for the HWDP tools to be put in service under different configurations. Either at the bottom of the drill string near the drill bit for vertical well configurations or on top of the drill string for weight application on horizontal or extended reach applications. An operator in northwestern Canada has replaced standard HWDP with enhanced sour service HWDP in order to complete the programmed wells. These enhanced tools offer higher tensile and torque capabilities and improved toughness than standard HWDP tools and in addition, provide protection against sour service conditions. The use of second-generation double shoulder connections (2nd-Gen. DSC) has also provided added torque and tensile capacities to these versatile HWDP tools. For over a year more than a dozen wells have been drilled employing these enhanced BHA tools and have helped the operator reach its targets through sour service formations and produce wells in a safe and cost effective manner. (author)

  4. Pressure transducers

    International Nuclear Information System (INIS)

    Strain gauges pressure transducers types are presented. Models, characteristics and calibration procedures were also analysed. Initially, a theoretical study was accomplished to evaluate metallic alloys behavior on sensing elements manufacturing, and diaphragm was used as deflecting elements. Electrical models for potenciometric transducers were proposed at the beginning and subsequently comproved according our experiments. Concerning bridge transducers, existing models confirmed the conditions of linearity and sensitivity related to the electrical signal. All the work done was of help on the calibration field and pressure measurements employing unbounded strain gauge pressure transducers

  5. [Individual pressure tolerance--a "target" pressure?]. (United States)

    Bogdănici, C; Vancea, P P


    In literature there are many meanings for the limit between normal and pathological intraocular pressure: "normative pressure", "critic pressure", "individual tolerance pressure" and "target pressure". The aim of this paper is to demonstrate that these terms are synonymous. PMID:10756882

  6. Pressure Drop (United States)

    Lawson, Mike


    Mike Lawson briefly discussed pressure drop for aerospace applications and presented short stories about adventures experienced while working at NASA and General Dynamics, including exposure to technologies like the Crew and Equipment Translation Aid (CETA) cart and the SWME.

  7. Pressure sensor

    Energy Technology Data Exchange (ETDEWEB)

    Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.


    Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  8. Chemical pressure


    Hauser, Andreas; Amstutz, Nahid; Delahaye, Sandra; Sadki, Asmaâ; Schenker, Sabine; Sieber, Regula; Zerara, Mohamed


    The physical and photophysical properties of three classic transition metal complexes, namely [Fe(bpy)3]2+, [Ru(bpy)3]2+, and [Co(bpy)3]2+, can be tuned by doping them into a variety of inert crystalline host lattices. The underlying guest-host interactions are discussed in terms of a chemical pressure.

  9. Pressurized hopper

    International Nuclear Information System (INIS)

    A Secure Automated Fuel Fabrication Line is being developed to reduce personnel exposure and to improve safeguards. Fertile and fissile fuel powders are blended in the line for making fuel pellets. A pressurized hopper was developed for use not only as a blender, but also as a storage and feeding device. It works with or without injection tubes to produce a well-blended powder with reduced agglomerate population. Results of blending experiments using dry Kaolin clay and Tempra pigment are given

  10. Blood Pressure Quiz (United States)

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  11. Hypertension (High Blood Pressure) (United States)

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  17. Bedsores (Pressure Ulcers) (United States)

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    Institute of Scientific and Technical Information of China (English)

    李涛; 董平川; 曹丽丽


    Aiming at the heterogeneity of formation itself and the polluted belts around the wells in the processes of drilling, well completion and production for coal-bed gas, the well-testing interpretation model for the composite coal-bed gas with double porosities is established. The model considers not only the effects of borehole storage effect and skin effect, but also the non-equilibrium adsorption and quasi-steady seepage conditions. It gives the pressure solution under the condition of infinite outer boundary, and furthermore the typical curves of bottom hole pressure drop are drawn, the influences of each parameter on the curves are analyzed. The study achievements have provided a theoretical basis for coal-bed gas reservoir development.%针对煤层气在钻井、完井、开采过程中井周围产生污染带以及地层本身的非均质情况,建立了既考虑井筒储存效应及表皮污染的影响,又考虑非平衡态吸附及拟稳态渗流条件的分区复合煤层气试井解释模型,求出了无限大外边界条件下的煤层气藏压力解,并绘制了井底压降典型曲线,就各参数对典型曲线的影响进行了分析.研究成果为煤层气藏开发提供了理论依据.

  20. High Blood Pressure (United States)

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  1. High blood pressure - infants (United States)

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  3. Preventing pressure ulcers (United States)

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  6. An investigation of constant pressure gas well testing influenced by high velocity flow

    Energy Technology Data Exchange (ETDEWEB)

    Berumen, S. [PEMEX Exploracion-Produccion, Mexico City (Mexico); Samaniego, F. [Universidad de Mexico, Mexico City (Mexico). Facultad de Ingeniera; Cinco-Ley, H. [Universidad de Mexico, Mexico City (Mexico). Facultad de Ingeniera; Bouhroum, A.


    This paper presents the results of a study of transient pressure analysis of gas flow under either constant bottom-hole conditions or the constant wellhead pressure conditions. The effect of formation damage, wellbore storage and high velocity flow are included in the model. The analysis of simulated well tests showed that the interpretation methods used for liquid flow are generally accurate when the p{sub p}(p) is used. For these conditions, a graph of 1/q{sub D} vs log t{sub D} presents gradually lower values of 1.1513 as the value of p{sub wf} decreases: For pressure buildup conditions a graph of p{sub pD}(1, {Delta}t{sub aD})/q{sub D}({Delta}t{sub aD}=0) vs (t{sub aD}+{Delta}t{sub aD})/{Delta}t{sub aD} shows values of this slope within 1% of the 1.1513 value. The maximum error was in the rate performance simulated cases that included high-velocity flows; being less than 13%. This upper limit occurs when the formation has a relatively `high` permeability (around 1 mD) and the rate performance test is affected by high-velocity flow. It was found that pressure buildup tests are superior to rate performance tests because high-velocity flow does not affect the slope of the straight line portion of the buildup curve. However, it was also found, through derivative analysis of simulated buildup tests, that the skin factor is sensibly miscalculated when the high-velocity flow effect is singificant. This problem could lead to errors in the calculation of the skin factor, s, up to 300%. (orig.) [Deutsch] Vorgestellt werden instationaere Testergebnisse an Gas-Sonden unter konstanten Bohrlochsohlenbedingungen bzw. konstantem Bohrlochkopfdruck. Folgende Stoereffekte: Sondennahe Tragerschaedigung, Speicherkapazitaet des Bohrloches und die bei der Gasstroemung eintretende hohe Fliessgeschwindigkeit werden beruecksichtigt. Die Auswertung von simulierten Testergebnissen zeigt, dass die zur Interpretation von Erdoelsonden bewaehrten Verfahren in der Darstellung p{sub p}(p) gute

  7. High blood pressure medications (United States)

    ... this page: // 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, ...

  8. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Preventing Pressure Sores Preventing Pressure Sores Transition from Hospital to Home Transition from Hospital to Home Spasticity, Physical Therapy-Lokomat Spasticity, Physical Therapy-Lokomat ...

  9. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R


    Pressure vessels are closed containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They have a variety of applications in industry, including in oil refineries, nuclear reactors, vehicle airbrake reservoirs, and more. The pressure differential with such vessels is dangerous, and due to the risk of accident and fatality around their use, the design, manufacture, operation and inspection of pressure vessels is regulated by engineering authorities and guided by legal codes and standards. Pressure Vessel Design Manual is a solutions-focused guide to the many problems and technical challenges involved in the design of pressure vessels to match stringent standards and codes. It brings together otherwise scattered information and explanations into one easy-to-use resource to minimize research and take readers from problem to solution in the most direct manner possible. * Covers almost all problems that a working pressure vessel designer can expect to face, with ...

  10. Blood Pressure Medicines (United States)

    High blood pressure, also called hypertension, usually has no symptoms. But it can cause serious problems such as stroke, heart ... kidney failure. If you cannot control your high blood pressure through lifestyle changes such as losing weight and ...

  11. Hypertension (High Blood Pressure) (United States)

    ... blood pressure with the development of a practical method to measure it. Physicians began to note associations between hypertension and risk of heart failure, stroke, and kidney failure. Although scientists had yet to prove that lowering blood pressure ...

  12. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Cord Injury 101 Spinal Cord Injury 101 The Basics of Spinal Cord Injury Rehabilitation The Basics of Spinal Cord Injury Rehabilitation Preventing Pressure Sores Preventing Pressure Sores Transition ...

  13. High blood pressure (United States)

    ... you are at risk for: Bleeding from the aorta, the large blood vessel that supplies blood to ... tests Blood pressure check Blood pressure References American Diabetes Association. Standards of medical care in diabetes-2015 ...

  14. Pressure surge attenuator (United States)

    Christie, Alan M.; Snyder, Kurt I.


    A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

  15. Development of a bottom-hole gamma-ray diagnostic capability for high-level environments, during CTBT on-site inspection drilling

    International Nuclear Information System (INIS)

    Testing completed at NTS confirmed that the Anadrill gamma-ray tool was fully operational up to 50,000 API, as specified in the initial objective. Recorded results were within expected ranges when compared to the hand-held detector. The gamma-ray module will require special 'high-rate' detection software to be loaded prior to drilling operations. The other components within the VIPER system have been modified to operate with either software (normal or 'high-rate') installed in the gamma-ray module. The successful completion of this test is but one step towards the main goal. The next step will be testing this module in the VIPER tool during an actual 're-entry' drilling operation, which could be performed at NTS on a former U.S. event. (author)

  16. Dynamic Pressure Difference Microphones (United States)

    Werner, E.

    A microphone with a diaphragm that is exposed to the sound field only on one side responds essentially to the sound pressure. This quantity is a scalar, and thus, pressure microphones are essentially omnidirectional (see Chapter 66). However, directional microphones are useful because they make it possible to focus on a source and suppress background noise from other directions. Most directional microphones respond to the gradient of the sound pressure, to combinations of the sound pressure and its gradient, or to combinations of higher order spatial derivatives of the sound pressure.

  17. Pressure measuring probe (United States)

    Ashby, George C., Jr. (Inventor)


    The invention is a probe for measuring changes in pressure in a high velocity fluid stream over and adjacent to the surface of an object. The probe is formed of an exterior housing having a closed pressure chamber in which a piezoelectric pressure transducer is mounted. An open connector tube having a probe tip passes a portion of the fluid stream into the closed pressure chamber; any change of pressure within, which requires a settling-time to appear in the closed pressure chamber, is inversely proportional to the cross-sectional area of the connector tube. A cooling chamber formed around the pressure chamber is connected to a source of cooling fluid by means of inlet and outlet tubes.

  18. An electrokinetic pressure sensor

    International Nuclear Information System (INIS)

    A new concept for a micro pressure sensor is demonstrated. The pressure difference between the inlet and the outlet of glass nanochannels is obtained by measuring the electrokinetically generated electric potential. To demonstrate the proposed concept, experimental investigations are performed for 100 nm wide nanochannels with sodium chloride solutions having various concentrations. The proposed pressure sensor is able to measure the pressure difference within a 10% deviation from linearity. The sensitivity of the electrokinetic pressure sensor with 10−5 M sodium chloride solution is 18.5 µV Pa−1, which is one order of magnitude higher than that of typical diaphragm-based pressure sensors. A numerical model is presented for investigating the effects of the concentration and the channel width on the sensitivity of the electrokinetic pressure sensor. Numerical results show that the sensitivity increases as the concentration decreases and the channel width increases

  19. Pressure locking test results

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others


    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; the authors will publish the results of their thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  20. Measurement of endolymphatic pressure. (United States)

    Mom, T; Pavier, Y; Giraudet, F; Gilain, L; Avan, P


    Endolymphatic pressure measurement is of interest both to researchers in the physiology and pathophysiology of hearing and ENT physicians dealing with Menière's disease or similar conditions. It is generally agreed that endolymphatic hydrops is associated with Menière's disease and is accompanied by increased hydrostatic pressure. Endolymphatic pressure, however, cannot be measured precisely without endangering hearing, making the association between hydrops and increased endolymphatic pressure difficult to demonstrate. Several integrated in vivo models have been developed since the 1960s, but only a few allow measurement of endolymphatic hydrostatic pressure. Models associating measurement of hydrostatic pressure and endolymphatic potential and assessment of cochlear function are of value to elucidate the pathophysiology of endolymphatic hydrops. The present article presents the main types of models and discusses their respective interest. PMID:25467202

  1. Pressure cryocooling protein crystals (United States)

    Kim, Chae Un; Gruner, Sol M.


    Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.

  2. High-Pressure Microfluidics


    Ogden, Sam


    In this thesis, some fundamentals and possible applications of high-pressure microfluidics have been explored. Furthermore, handling fluids at high pressures has been addressed, specifically by creating and characterizing strong microvalves and pumps. A variety of microstructuring techniques was used to realize these microfluidic devices, e.g., etching, lithography, and bonding. To be able to handle high pressures, the valves and pumps need to be strong. This necessitates a strong actuator ma...

  3. Controlling your high blood pressure (United States)

    ... that is healthy for you. Checking Your Blood Pressure Your blood pressure can be measured at many places, including: ... Alternative Names Controlling hypertension Images Taking your blood pressure at home Blood pressure check Low sodium diet References American Diabetes ...

  4. What Is High Blood Pressure? (United States)

    ... also known as blood vessels and capillaries. The pressure --- blood pressure --- is the result of two forces. The ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

  5. High Blood Pressure Fact Sheet (United States)

    ... much alcohol. Signs and Symptoms of High Blood Pressure High blood pressure usually has no warning signs or symptoms , ... they are at high risk for high blood pressure . Blood Pressure Levels Normal systolic: less than 120 mmHg ...



    M. F. VALIM; Barros, S.


    Blood pressure is the force of blood against artery walls. It is measured in millimeters of mercury (mm Hg) and recorded as two numbers: systolic pressure (as the heart contracts) over diastolic pressure (as the heart relaxes between beats). High blood pressure (hypertension) is defined as chronically elevated high blood pressure, with systolic blood pressure (SBP) of 140 mm Hg or greater, and diastolic blood pressure (DBP) of 90 mm Hg or greater. High blood pressure ...

  7. Preventing High Blood Pressure (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 ...

  8. Coping With Inflation Pressures

    Institute of Scientific and Technical Information of China (English)


    The pressure of higher prices is a major problem confronting the Chinese economy"We will be facing fairly great price pressures in 2008,"said Xie Fuzhan,Director of the National Bureau of Statistics(NBS),on January 24."Even if there are no new fac- tors causing price hikes,the inertia from the rises in 2007 is still devastating."

  9. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Injury Coping with a New Injury Adjusting to Social Life in a Wheelchair Adjusting to Social Life in a Wheelchair Substance Abuse and Spinal ... sore required? How long is the typical healing time for a pressure sore? Why do some pressure ...

  10. Pressure surge attenuator

    International Nuclear Information System (INIS)

    A pressure surge attenuation arrangement comprises crushable metal foam disposed adjacent regions adapted to be expanded by a pressure surge. In a pipe system such region consists of a thin walled inner pipe surrounded by a housing with crushable metal foam disposed in the space between the housing and the inner pipe. (author)

  11. Neonatal Pressure Ulcer Prevention. (United States)

    Scheans, Patricia


    The incidence of pressure ulcers in acutely ill infants and children ranges up to 27 percent in intensive care units, with a range of 16-19 percent in NICUs. Anatomic, physiologic, and developmental factors place ill and preterm newborns at risk for skin breakdown. Two case studies illustrate these factors, and best practices for pressure ulcer prevention are described. PMID:26803094

  12. Complexities of the analysis of surface shut-in DST in an offshore volatile oil reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Kazemi, H.; Haws, G.W.; Kunzman, W.J.; Milton, H.W.; Halbert, W.G.


    A surface shut-in drill-stem testing (DST) procedure was used on delineation wells in an offshore volatile oil reservoir. Bottom-hole pressures were recorded on all tested intervals, and surface pressures and temperatures were recorded on most of the tests. Subsequent type-curve plots and the Horner plots of the bottom hole pressure buildup data of several wells did not conform to classical theory. This report describes a new theory that explains the discrepancies, relating them to the combined effects of a set of wellbore phenomena during pressure buildup testing. 7 refs.

  13. High Blood Pressure (Hypertension) (United States)

    ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Information by Audience For Women High Blood Pressure (Hypertension) Share Tweet Linkedin Pin ...

  14. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... wheelchair seat cushion? What’s important to know about positioning in bed to prevent pressure sores? What is “ ... provide medical advice, recommend or endorse health care products or services, or control the information found on ...

  15. Preventing Pressure Sores (United States)

    ... wheelchair seat cushion? What’s important to know about positioning in bed to prevent pressure sores? What is “ ... provide medical advice, recommend or endorse health care products or services, or control the information found on ...

  16. More Pressure on Iran

    Institute of Scientific and Technical Information of China (English)


    As the UN Security Council adopts a new resolution to pressure Iran over its nuclear activities, the country maintains a tough stance On March 24, the UN Security Council unanimously adopted a new resolution imposing tougher sanctions against Iran to

  17. A pressure regulator

    International Nuclear Information System (INIS)

    A device for regulating the pressure of a gas in a glove box comprises a resiliently biassed pressure sensitive diaphragm and a spool valve operable by deflection of the diaphragm. The diaphragm is arranged to be exposed on one side to atmospheric pressure and on the other side to the pressure of the gas in the glove box, and the spool valve is used to control simultaneously the rates at which gas is pumped in and out of the glove box. The valve spool has two axially spaced circumferential grooves A, B which provide communication between conduits C, D and E, F respectively, the flow control along each path being effected by means of apertures in a sleeve within which the spool slides. (author)

  18. Critical CRBR core pressure

    International Nuclear Information System (INIS)

    The conditions are detailed under which gas pressure will cause or initiate failure in the structural containment of the fuel core. The Clinch River Breeder Reactor Plant is the prototype structure. Two general classes of problems have been studied, representing two entirely distinct configurations of containment failure. The first model determines the minimum pressure to lift a portion or the entire core from its containment. The second model estimates the critical pressure above which the fuel rods interior to the hexagonal fuel can warp, leading to blockage of the gas passages. Such blockage might cause further buildup of the gas pressure to a level causing the failure of the fuel rod containment in the hexagonal fuel container

  19. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... with spinal cord injuries? What are the six stages of a pressure sore and how are they ... entire family FacingDisability is designed to provide Internet-based information and support for people with spinal cord ...

  20. Skin (Pressure) Sores (United States)

    ... every 15 minutes. Use special foam or gel seat cushions to reduce pressure. Choose clothing that isn’ ... any open sore with water very carefully and cover with a bandage. Do this every time the ...

  1. Capacitance pressure sensor (United States)

    Eaton, William P.; Staple, Bevan D.; Smith, James H.


    A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).

  2. Pressure Transducer Locations (United States)

    National Aeronautics and Space Administration — Files are located here, defining the locations of the pressure transducers on the HIRENASD model. These locations also correspond to the locations that analysts...

  3. Metastable Systems under Pressure

    CERN Document Server

    Rzoska, Sylwester; Mazur, Victor


    The fundamental insight and the technological & environmental relevance of metastable systems have given a strong impetus from the last decade development of extreme pressures experimental techniques, from the GPa region to the challenging negative pressures domain. The ultimate verification of theoretical models and reliable equations for portraying basic properties for such systems seems to be possible only when including temperature and pressure paths. This volume presents a set of papers related to novel findings on the glass transition phenomenon, phase transitions in liquid crystals, critical mixtures, bioliquids, geophysical system which can reveal surprising "secret" features only when using extreme pressures. This can be illustrated by the link between colloidal and molecular glassformers, the universal onset of the non-trivial dynamics in glasses, demistification of the secondary relaxation or novel findings associated with liquid - liquid near critical transitions in critical mixture, liquid cr...

  4. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... sores? What's the best way to do daily skin inspections? What are the most important things for ... in bed to prevent pressure sores? What is “skin tolerance” and how can it be increased? What ...

  5. Deuterium high pressure target

    International Nuclear Information System (INIS)

    The design of the deuterium high-pressure target is presented. The target having volume of 76 cm3 serves to provide the experimental research of muon catalyzed fusion reactions in ultra-pure deuterium in the temperature range 80-800 K under pressures of up to 150 MPa. The operation of the main systems of the target is described: generation and purification of deuterium gas, refrigeration, heating, evacuation, automated control system and data collection system

  6. Deuterium High Pressure Target

    CERN Document Server

    Perevozchikov, V; Vinogradov, Yu I; Vikharev, M D; Ganchuk, N S; Golubkov, A N; Grishenchkin, S K; Demin, A M; Demin, D L; Zinov, V G; Kononenko, A A; Lobanov, V N; Malkov, I L; Yukhimchuk, S A


    The design of the deuterium high-pressure target is presented. The target having volume of 76 cm^3 serves to provide the experimental research of muon catalyzed fusion reactions in ultra-pure deuterium in the temperature range 80-800 K under pressures of up to 150 MPa. The operation of the main systems of the target is described: generation and purification of deuterium gas, refrigeration, heating, evacuation, automated control system and data collection system.

  7. Delay Pressure Detection Method to Eliminate Pump Pressure Interference on the Downhole Mud Pressure Signals


    Yue Shen; Ling-Tan Zhang; Shi-Li Cui; Li-Min Sheng; Lin Li; Yi-Nao Su


    The feasibility of applying delay pressure detection method to eliminate mud pump pressure interference on the downhole mud pressure signals is studied. Two pressure sensors mounted on the mud pipe in some distance apart are provided to detect the downhole mud continuous pressure wave signals on the surface according to the delayed time produced by mud pressure wave transmitting between the two sensors. A mathematical model of delay pressure detection is built by analysis of transmission path...

  8. Home monitoring of blood pressure


    McGrath, Barry P


    Home blood pressure monitoring is the self-measurement of blood pressure by patients. In the diagnosis and management of high blood pressure it is complementary to 24-hour ambulatory blood pressure monitoring and clinic blood pressure measurements. Home monitoring can also help to identify white-coat and masked hypertension.

  9. Blood Pressure vs. Heart Rate (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Blood Pressure vs. Heart Rate Updated:Aug 30,2016 Blood ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

  10. Tevatron quench pressure measurement

    International Nuclear Information System (INIS)

    The upcoming lower temperature/higher energy upgrade to the Fermilab Tevatron accelerator has raised questions concerning peak pressures during magnet system quenches. An experiment was performed to measure the pressure versus time at various quench energies in several devices in the Tevatron. A smaller study also looked at the temperature and mass flow rate versus time. Data was captured in a PC based circular buffer. The buffer captured ten seconds of data at 250 Hz for up to eight channels. Quenches ranging from 400 GeV to 1000 GeV were investigated. Peak pressures of 1.24 MPa (180 psia) were measured at 1000 GeV. Peak pressure increased linearly with quench energy up to 950 GeV, where it flattened off. Likewise, the time to reach peak pressure decreased linearly until 900 GeV, where it flattened off at 280 ms. The process appears to become heat transfer limited at about 900 GeV. This results in reasonable peak quench pressures at the expense of the coil reaching higher peak temperatures (not measured). The existing cryostats and relieving systems in the Tevatron will be sufficient for the new low temperature upgrade

  11. The cystogram under pressure

    International Nuclear Information System (INIS)

    Full text: The direct radionuclide cystogram (DRC) is a sensitive test for the detection of vesico-ureteric reflux (VUR), but has no recognized grading system. The X-ray micturating cystourethrogram (MCU) has an international grading system based on the calibre of the urinary system and the level of reflux reached. While reflux grades of 4 and 5 are more serious, the condition may resolve spontaneously with maturation almost irrespective of the grade. A functional grading system of the DRC has been applied for 14 years in our hospital. It is considered that reflux first occurring at low bladder volume/pressure presents a greater risk of renal insult, as reflux will occur more often. Conversely, the higher pressure grades may predict reflux that is progressing towards natural resolution. Results of 82 reflux infants first investigated under the age of 1 year (average age 0.42 years) with serial cystograms (average age 1.5 years) indicates that low pressure reflux resolves at 42%, moderate pressure 78%, high 92% and voiding grades 67%. Dual cystograms (MCU and DRC) on 62 of these infants at the same setting detected a total of 104 units of reflux, the MCU detecting only 48 and the DRC 96 units (sensitivity 46% and 92% respectively). In addition, low pressure reflux reflected a higher risk of renal insult with 44% renal dimercaptosuccinic acid (DMSA) scans reported with defects against an overall DMSA rate from all grades of 33%. The DRC volume/pressure grading offers a functional assessment with predictive value. In the young infant it would appear that the MCU has poor sensitivity for the detection of reflux and that it is the technique 'under pressure' from the direct radionuclide alternative

  12. What Causes High Blood Pressure? (United States)

    ... whether imbalances in this system cause high blood pressure. Blood Vessel Structure and Function Changes in the structure ... can affect blood pressure. Genetic Causes of High Blood Pressure Much of the understanding of the body systems ...

  13. Prevention of High Blood Pressure (United States)

    ... from the NHLBI on Twitter. Prevention of High Blood Pressure Healthy lifestyle habits, proper use of medicines, and ... high blood pressure or its complications. Preventing High Blood Pressure Onset Healthy lifestyle habits can help prevent high ...

  14. Medications for High Blood Pressure (United States)

    ... dangerous as elevations of both systolic and diastolic pressure. Blood pressure is elevated for two main reasons: too ... and Angiotensin II receptor blockers (ARBs), reduce blood pressure by relaxing blood vessels Beta blockers, which also cause the heart ...

  15. Diagnosis of High Blood Pressure

    Medline Plus

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

  16. Inexpensive Pressure-Relief Valve (United States)

    Theordore, E. A.


    Simple device vents excess low-pressure gas. Inexpensive pressure relief valve built from polyvinylchloride pipe. Valve suitable for low pressure-- 25 to 50 cm of mercury-- and flow rates up to 14 m3/min.

  17. Diagnosis of High Blood Pressure

    Medline Plus

    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 ...

  18. Reotemp Pressure Indicator - Local Pressure Indication to Monitor the SCHe Supply Bottle Pressure

    International Nuclear Information System (INIS)

    These 0-3000 psig range pressure indicators are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. These accident monitoring local pressure indicators monitor the SCHe supply bottle pressure. There is one pressure indicator for each SCHe supply (4)

  19. Passive blast pressure sensor (United States)

    King, Michael J.; Sanchez, Roberto J.; Moss, William C.


    A passive blast pressure sensor for detecting blast overpressures of at least a predetermined minimum threshold pressure. The blast pressure sensor includes a piston-cylinder arrangement with one end of the piston having a detection surface exposed to a blast event monitored medium through one end of the cylinder and the other end of the piston having a striker surface positioned to impact a contact stress sensitive film that is positioned against a strike surface of a rigid body, such as a backing plate. The contact stress sensitive film is of a type which changes color in response to at least a predetermined minimum contact stress which is defined as a product of the predetermined minimum threshold pressure and an amplification factor of the piston. In this manner, a color change in the film arising from impact of the piston accelerated by a blast event provides visual indication that a blast overpressure encountered from the blast event was not less than the predetermined minimum threshold pressure.

  20. Downhole pressure attenuation apparatus

    International Nuclear Information System (INIS)

    This patent describes a process for preventing damage to tool strings and other downhole equipment in a well caused by pressures produced during detonation of one or more downhole explosive devices. It comprises adding to a tool string at least one pressure attenuating apparatus for attenuating the peak pressure wave and quasi-static pressure pulse produced by the explosive devices, the pressure attenuating apparatus including an initially closed relief vent including tubing means supporting a plurality of charge port assemblies each including an explosive filled shaped charge and a prestressed disc, the shaped charges interconnected by a detonating cord, the amount of explosive in each shaped charge being sufficient to rupture its associated disc without damaging surrounding tubular bodies in the well, and a vent chamber defined by the tubing means and providing a liquid free volume, and opening the relief vent substantially contemporaneously with downhole explosive device detonation by detonating the shaped charges to rupture the discs of the charge port assemblies

  1. Pressure tube type reactor

    International Nuclear Information System (INIS)

    Heretofore, a pressure tube type reactor has a problem in that the evaluation for the reactor core performance is complicate and no sufficient consideration is made for the economical property, to increase the size of a calandria tank and make the cost expensive. Then, in the present invention, the inner diameter of a pressure tube is set to greater than 50% of the lattice gap in a square lattice like arrangement, and the difference between the inner and the outer diameters of the calandria tube is set smaller than 20% of the lattice gap. Further, the inner diameter of the pressure tube is set to greater than 40% and the difference between the inner and the outer diameters of the calandria tube is set smaller than 30% of the lattice gap in a triangle lattice arrangement. Then, heavy water-to-fuel volume ratio can be determined appropriately and the value for the coolant void coefficient is made more negative side, to improve the self controllability inherent to the reactor. In particular, when 72 to 90 fuel rods are arranged per one pressure tube, the power density per one fuel rod is can be increased by about twice. Accordingly, the number of the pressure tubes can be reduced about to one-half, thereby enabling to remarkably decrease the diameter of the reactor core and to reduce the size of the calandria, which is economical. (N.H.)

  2. Pressure measurement on rotating machinery (United States)

    Pemberton, Addison; Harris, Louis R.

    The objective of this paper is to describe the use of pressure scanners for measuring multiple unknown pressures in rotating machinery. Pressure scanners consist of stepper driven selector valves, which sequentially connect unknown pressures and apply these pressures to a single pressure transducer. This generates analog voltage signals which can be computerized and plotted while a pressure test is in progress. When an electrical selector switch on the same stepper driven shaft is added, thermocouple signals can be brought out of a rotating machine synchronously with pressure data.

  3. Reactor pressure boundary materials

    International Nuclear Information System (INIS)

    With a long-term operation of nuclear power plants, the component materials are degraded under severe reactor conditions such as neutron irradiation, high temperature, high pressure and corrosive environment. It is necessary to establish the reliable and practical technologies for improving and developing the component materials and for evaluating the mechanical properties. Especially, it is very important to investigate the technologies for reactor pressure boundary materials such as reactor vessel and pipings in accordance with their critical roles. Therefore, this study was focused on developing and advancing the microstructural/micro-mechanical evaluation technologies, and on evaluating the neutron irradiation characteristics and radiation effects analysis technology of the reactor pressure boundary materials, and also on establishing a basis of nuclear material property database

  4. The pressure suppression system

    International Nuclear Information System (INIS)

    Nuclear plants with boiling water reactors have a safety containment with a pressure suppression system (PSS). Proceeding on significant self-developments, today the three PSS-lines of General Electric Co. (GE), Kraftwerk Union AG (KWU) and ASEA-ATOM are predominant, which are currently represented by the MARK III type, the KWU type 72 and the BWR 75 containment. In addition, there are special developments for the nuclear ship propulsion and for the pressurized water reactors in the Soviet Union. Key design values of the PSS allow a first valuation of its loads during a hypothetical loss-of-coolant accident. (orig.)

  5. A life under pressure

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; von Holstein-Rathlou, Niels-Henrik


    Microvessels live 'a life under pressure' in several ways. In a literal sense, vessels of the microcirculation are exposed to high levels of stress caused primarily by the intravascular pressure head. In a figurative sense, the individual vessel and the microvascular network as a whole must...... stress component has a huge impact on the state of the vascular wall. It is involved as a unifying factor on vastly different timescales in processes as diverse as acute regulation of vessel diameter, structural vessel remodelling and growth or atrophy of the vascular wall. The aim of this MiniReview was...

  6. Reactor pressure vessel materials

    International Nuclear Information System (INIS)

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. Chapter 3 offers a detailed treatment of the selection criteria and properties of reactor pressure vessel materials. The main attention is directed towards steel and ingot making and the subsequent material processing

  7. Krypton oxides under pressure. (United States)

    Zaleski-Ejgierd, Patryk; Lata, Pawel M


    Under high pressure, krypton, one of the most inert elements is predicted to become sufficiently reactive to form a new class of krypton compounds; krypton oxides. Using modern ab-initio evolutionary algorithms in combination with Density Functional Theory, we predict the existence of several thermodynamically stable Kr/O species at elevated pressures. In particular, our calculations indicate that at approx. 300 GPa the monoxide, KrO, should form spontaneously and remain thermo- and dynamically stable with respect to constituent elements and higher oxides. The monoxide is predicted to form non-molecular crystals with short Kr-O contacts, typical for genuine chemical bonds. PMID:26830129

  8. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... how is it treated? What's the most important thing to do to prevent pressure sores? A spinal cord injury affects the entire family FacingDisability is designed to provide Internet-based information and support for people with spinal ...

  9. Blood pressure and atherosclerosis

    Institute of Scientific and Technical Information of China (English)


    2010319 Effects of combined application of Xuezhikang capsule with hypotensive drugs on arterial compliance and smoothness of the dynamic blood pressure. ZHU Zongtao(朱宗涛),et al. Dept Cardiol, Centr People’s Hosp, Tengzhou 277500.Chin J Integr Tradit & West Med 2010;30


    NARCIS (Netherlands)

    Beukers, A.; De Jong, T.


    Abstract of WO 9717570 (A1) The invention is directed to a wheel-shaped pressure-resistant vessel for gaseous, liquid or liquefied material having a substantially rigid shape, said vessel comprising a substantially continuous shell of a fiber-reinforced resin having a central opening, an inner l

  11. Magnetic measurements under pressure

    Czech Academy of Sciences Publication Activity Database

    Zentková, M.; Arnold, Zdeněk; Mihalik, M.; Mihalik, M.; Zentko, A.; Kamarád, Jiří; Mitróová, Z.; Mat`aš, S.


    Roč. 57, 8/S (2006), s. 29-32. ISSN 1335-3632 Institutional research plan: CEZ:AV0Z10100521 Keywords : hydrostatic pressure * Prussian blue analogues * AC susceptibility * intermetallic compound * ferromagnetism * errimagnetism Subject RIV: BM - Solid Matter Physics ; Magnetism

  12. Water vapor pressure calculation. (United States)

    Hall, J R; Brouillard, R G


    Accurate calculation of water vapor pressure for systems saturated with water vapor can be performed using the Goff-Gratch equation. A form of the equation that can be adapted for computer programming and for use in electronic databases is provided. PMID:4008425

  13. Pressure Effect on Extensional Viscosity

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Kjær, Erik Michael


    The primary object of these experiments was to investigate the influence of hydrostatic pressure on entrance flow. The effect of pressure on shear and extensional viscosity was evaluated using an axis symmetric capillary and a slit die where the hydrostatic pressure was raised with valves. The...... experiments show a significant increase in extensional viscosity with increasing pressure....

  14. Stroke and High Blood Pressure (United States)

    ... Pressure Tools & Resources Stroke More Stroke and High Blood Pressure Updated:Jan 6,2015 Stroke is a leading ... heart disease and stroke. Start exploring today ! High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  15. Potassium and High Blood Pressure (United States)

    ... Pressure Tools & Resources Stroke More Potassium and High Blood Pressure Updated:Mar 1,2016 A diet that includes ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  16. Types of Blood Pressure Medications (United States)

    ... Blood Pressure Tools & Resources Stroke More Types of Blood Pressure Medications Updated:Aug 26,2016 Many medications known ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  17. High Blood Pressure and Women (United States)

    ... High Blood Pressure Tools & Resources Stroke More High Blood Pressure and Women Updated:Aug 13,2014 Many people ... was last reviewed on 08/04/14. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  18. Myths about High Blood Pressure (United States)

    ... Pressure Tools & Resources Stroke More Myths About High Blood Pressure Updated:Aug 12,2014 You CAN manage your ... was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... pressure. Using the results of your blood pressure test, your health care provider will diagnose prehypertension or high blood pressure ... same age, gender, and height . Once your health care provider ... he or she can order additional tests to determine if your blood pressure is due ...

  20. High pressure gas metering project

    International Nuclear Information System (INIS)

    The initial research and development of a system that uses high pressure helium gas to pressurize vessels over a wide range of pressurization rates, vessel volumes, and maximum test pressures are described. A method of controlling the mass flow rate in a test vessel was developed by using the pressure difference across a capillary tube. The mass flow rate is related to the pressurization rate through a real gas equation of state. The resulting mass flow equation is then used in a control algorithm. Plots of two typical pressurization tests run on a manually operated system are included

  1. Cerebrospinal Fluid Pressure and Glaucoma


    Jonas, Jost B; Ningli Wang


    Eyes with normal-pressure glaucoma and those with high-pressure glaucoma can show a similar optic nerve head appearance, while eyes with vascular optic neuropathies show a markedly different optic disc appearance. Factors in addition to intraocular pressure (IOP) may thus play a role in the pathogenesis of glaucomatous optic neuropathy. Clinical and experimental studies showed that (1) physiologic associations between cerebrospinal fluid (CSF) pressure, systemic arterial blood pressure, IOP a...

  2. Measurement of Strong Shock Pressure


    Hajime Takada; Daisuke Fujimaki; Takao Tsuboi


    This paper deals with measurement of a strong shock pressure like an imploding detonation of over 1 GPa which cannot be measured directly with currently available commercial pressure transducers. After the transfer functions of three kinds of materials were measured using a shock tube, Teflon was selected as a shock absorber. As an example of pressure beyond the limit of the pressure transducer, we tried to measure pressure at the center of an imploding detonation. From this measurement, we c...

  3. Negative pressure device for intra-abdominal pressure reduction

    Energy Technology Data Exchange (ETDEWEB)

    David, M; Geido, D; Pracca, F; Sanchez, G; Simini, F; Zoppolo, C [Nucleo de Ingenierfa Biomedica, Universidad de la Republica O. del Uruguay, Hospital de ClInicas, Av. Italia S/N, 11600, Montevideo (Uruguay)


    A device that generates negative extra-abdominal pressure (ABDOPRE) for treatment of patients with high intra-abdominal pressure was developed. It includes pressure sensors for transducing intra-abdominal pressure through an intra-vesical catheter and negative pressure in the vacuum bell which is placed over the abdomen. By means of a control system, a pattern for reducing IAP is set, according to a clinical protocol. The external negative pressure is generated using a vacuum pump connected to the bell. The system registers the values of interest for the medical history. The system is being tested over ICU patients, registering a satisfactory IAP reduction.

  4. High pressure shaft seal

    International Nuclear Information System (INIS)

    In relation to reactor primary coolant pumps, mechanical seal assembly for a pump shaft is disclosed which features a rotating seal ring mounting system which utilizes a rigid support ring loaded through narrow annular projections in combination with centering non-sealing O-rings which effectively isolate the rotating seal ring from temperature and pressure transients while securely positioning the ring to adjacent parts. A stationary seal ring mounting configuration allows the stationary seal ring freedom of motion to follow shaft axial movement up to 3/4 of an inch and shaft tilt about the pump axis without any change in the hydraulic or pressure loading on the stationary seal ring or its carrier. (author)

  5. Radiography of pressure ulcers

    International Nuclear Information System (INIS)

    In patients with longstanding and/or deep pressure ulcers radiology is usually consulted. Survey radiography and sinography in 14 patients with pressure ulcers (6 over the tuber ischii and 8 over the femoral trochanter) were evaluated. Osteomyelitic involvement of adjacent bone was revealed in 9 patients on survey radiography. However, it was usually impossible to assess whether or not bony involvement represents healed or active osteomyelitis. Sinography did not contribute to the assessment of whether or not adjacent cortical bone was involved. However, when a fistulation to an adjacent joint was revealed this contributed substantially to the preoperative planning of resection. We therefore recommend that survey radiography and sinography should be included in the evaluation of these patients but that the results from such examinations are critically evaluated. Joint involvement should be taken seriously as progression of septic arthritis usually occurs rapidly. (orig.)

  6. Nozzle limit pressure

    International Nuclear Information System (INIS)

    A brief description of the static method aiming to determined the collapse load in a structure of elastic-plastic material is given. This methodology together with the Finite Element Method in the field approximation, leads to a problem of minimizing a linear function with linear constraints. The application of this technique to axissymmetrical shells submmited to axissymmetric loads is analyzed; the numerical application is done for nozzles in pipelines and pressure vessels joints. (E.G.)

  7. Hyperbaric Pressure Control System


    Berg, Brian; Skjørten, Anders; Nicolaysen, Jonas; Skarseth, Thor Ove; Carlstedt, Jonas


    The requirement specification for the project where changed from delivery of a fully working product to contain only the design of this system due to long lead times on some of the high-pressure hydraulic parts. Three of the students where already working for FMC before project start, where two of them had experience with hydraulic Subsea Systems. Our project model where changed during the project. We started out with a Waterfall model and ended up with an Evolutionary model

  8. Reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Research and development activities related to reactor pressure vessel steels during 1997 are reported. The objectives of activities of the Belgian Nuclear Research Centre SCK/CEN in this domain are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate a methodology on a broad database; (3) to achieve regulatory acceptance and industrial use

  9. Pressure Garment Subsystem Roadmap (United States)

    Ross, Amy J.


    The Constellation program pressure garment subsystem (PGS) team has created a technical roadmap that communicates major technical questions and how and when the questions are being answered in support of major project milestones. The roadmap is a living document that guides the team priorities. The roadmap also communicates technical reactions to changes in project priorities and funding. This paper presents the roadmap and discusses specific roadmap elements in detail as representative examples to provide insight into the meaning and use of the roadmap.

  10. The pressurized water reactor

    International Nuclear Information System (INIS)

    Pressurized water reactor technology has reached a maturity that has engendered a new surge of innovation, which in turn, has led to significant advances in the technology. These advances, characterized by bold thinking but conservative execution, are resulting in nuclear plant designs which offer significant performance and safety improvements. This paper describes the innovations which are being designed into mainstream PWR technology as well as the desings which are resulting from such innovations. (author)

  11. High pressure gas target (United States)

    Gelbart, W.; Johnson, R. R.; Abeysekera, B.


    Compact, high pressure, high current gas target features all metal construction and semi-automatic window assembly change. The unique aspect of this target is the domed-shaped window. The Havar alloy window is electron beam welded to a metal ring, thus forming one, interchangeable assembly. The window assembly is sealed by knife-edges locked by a pneumatic toggle allowing a quick, in situ window change.


    Directory of Open Access Journals (Sweden)

    Ida Bagus Adi Kayana


    Full Text Available Head injury is the most significant cause of increased morbidity and mortality. An estimated 1.4 million head injuries occur each year, with and more than 1.1 million come to the Emergency Unit. On each patient head injury, an increase in intracranial pressure (ICP related to poor outcomes and aggressive therapy to increased ICP can improve the outcomes. ICP monitoring is the most widely used because of the prevention and control of ICP as well as maintain the pressure increase perfusion of cerebral (Cerebral Perfusion Pressure/CPP is the basic purpose of handling head injury. There are two methods of monitoring ICP that is an invasive methods (directly and non-invasive techniques (indirectly. The method commonly used, namely intraventricular and intraparenkimal (microtransducer sensor because it is more accurate but keep attention to the existence of the risk of bleeding and infection resulting from installation. Monitoring of ICT can determine the actions that avoid further brain injury, which can be lethal and irreversibel.

  13. Calculation of downhole pressure and optimization design of construction parameters for gas lift and foam combined technology%气举-泡排组合工艺井底压力计算及施工参数优化设计

    Institute of Scientific and Technical Information of China (English)

    汪来潮; 熊钰; 陈霖; 李娟; 黄雨


    In view of the model that the mixtures in the wellbore implementing gas lift and foam drainage combined technology is composed of foam and free gas out of foam which get off from each other, this paper introduced the parameter“foam retention rate”and then derived a series of formulas to calculate the density of foam,“foam retention rate”and the density of wellbore mixtures, so as to determine wellbore pressure profile and calculate bottom hole pressure. This paper also verified the feasibility of the calcula-tion method by the calculation examples and results comparison to provide guidance for the optimization design of implementation parameters. The calculation method only has to calculate with a computer grogram to solve the complex work of pressure testing and improve the economics.%基于气举-泡排组合工艺井井筒中的混合流体是由泡沫(或泡沫团)与泡沫外气体组成并相互滑脱这一模型,引入持泡率这一参数,相继推导了确定泡沫密度、持泡率和混合流体密度等主要参数的计算公式,从而可以确定井筒压力剖面并计算井底流压。通过实例计算与对比,验证了计算方法的可行性,为气举-泡排组合工艺的施工参数的优化设计提供指导。气举-泡排组合工艺的井筒压力剖面计算方法,只需借助于计算机程序,节约了复杂的测压作业,提高了经济效益。

  14. Pressure Drop in Cyclone Separator at High Pressure

    Institute of Scientific and Technical Information of China (English)


    For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air leakage from the stand pipe into the cyclone was specially focused. A semi-empirical model was developed for the predic tion of the pressure drop of the cyclone separator at different operate pressures with the effect of air leakage and inlet solid loading. The operate pressure, air leakage and inlet solid loading act as significant roles in cyclone pressure drop. The pressure drop increases with the increasing of pressure and decreases with the increasing of the flow rate of air leakage from the standpipe and with the increasing of the inlet solid loading.

  15. Measurement of Strong Shock Pressure

    Directory of Open Access Journals (Sweden)

    Hajime Takada


    Full Text Available This paper deals with measurement of a strong shock pressure like an imploding detonation of over 1 GPa which cannot be measured directly with currently available commercial pressure transducers. After the transfer functions of three kinds of materials were measured using a shock tube, Teflon was selected as a shock absorber. As an example of pressure beyond the limit of the pressure transducer, we tried to measure pressure at the center of an imploding detonation. From this measurement, we could estimate the pressure peak of about 1.7 GPa.

  16. Pressurized thermal shock (PTS)

    International Nuclear Information System (INIS)

    In the present work, a description of Thermal Shock in Pressurized conditions (PTS), and its influence in the treatment of the integrity of the pressure vessel (RPV) of a Pressurized Water Reactor (PWR) and/or of a Heavy water Pressurized water Reactor (PHWR) is made. Generally, the analysis of PTS involves a process of three stages: a-) Modeling with a System Code of relevant thermohydraulics transients in reference with the thermal shock; b-) The local distribution of temperatures in the downcomer and the heat transference coefficients from the RPV wall to the fluid, are determined; c-) The fracture mechanical analysis. These three stages are included in this work: Results with the thermohydraulics code Relap5/mod.3, are obtained, for a LOCA scenario in the hot leg of the cooling System of the Primary System of the CAN-I reactor. The method used in obtaining results is described. A study on the basis of lumped parameters of the local evolutions of the temperature of the flow is made, in the downcomer of the reactor pressure vessel. The purpose of this study is to determine how the intensification of the stress coefficient, varies in function of the emergency injected water during the thermohydraulic transients that take place under the imposed conditions in the postulated scene. Specially, it is considered a 50 cm2 break, located in the neighborhoods of the pressurized with the corresponding hot leg connection. This size is considered like the most critical. The method used to obtain the results is described. The fracture mechanical analysis is made. From the obtained results we confirmed that we have a simple tool of easy application in order to analyze phenomena of the type PTS in the postulated scenes by break in the cold and hot legs of the primary system. This methodology of calculus is completely independent of the used ones by the Nucleoelectrica Argentina S.A. (NASA) in the analysis of the PTS phenomena in the CAN-I. The results obtained with the adopted

  17. Blood Pressure Matters: Keep Hypertension in Check (United States)

    ... cuff, or an automatic device may measure the pressure. Blood pressure is given as 2 numbers. The first ... described above. High Blood Pressure NIHSeniorHealth: High Blood Pressure High Blood Pressure and Kidney Disease Heart and Vascular Diseases ...

  18. Questions and Answers about High Blood Pressure (United States)

    ... Blood Pressure Page Content What is high blood pressure? Blood pressure is the force of blood against the ... do I know if I have high blood pressure? High blood pressure is often called "the silent killer" because ...

  19. Saltstone Osmotic Pressure

    International Nuclear Information System (INIS)

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR-2013-0004. Simulated saltstone typically has very low permeability (Dixon et al. 2008) and pore water that contains a large concentration of dissolved salts (Flach and Smith 2013). Pore water in simulated saltstone has a high salt concentration relative to pore water in concrete and groundwater. This contrast in salt concentration can generate high osmotic pressures if simulated saltstone has the properties of a semipermeable membrane. Estimates of osmotic pressure using results from the analysis of pore water collected from simulated saltstone show that an osmotic pressure up to 2790 psig could be generated within the saltstone. Most semi-permeable materials are non-ideal and have an osmotic efficiency 3, KNO3, Na3PO4x12H 2O, and K3PO4 when exposed to a dilute solution. Typically hydraulic head is considered the only driving force for groundwater in groundwater models. If a low permeability material containing a concentrated salt solution is present in the hydrogeologic sequence large osmotic pressures may develop and lead to misinterpretation of groundwater flow and solute transport. The osmotic pressure in the semi-permeable material can significantly impact groundwater flow in the vicinity of the semi-permeable material. One possible outcome is that groundwater

  20. Diagnosis of High Blood Pressure

    Medline Plus

    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 ...

  1. High blood pressure and diet (United States)

    ... this page: // 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 ...

  2. 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 ...

  3. High pressure diffraction at ISIS

    International Nuclear Information System (INIS)

    The development of the high pressure diffraction programme at ISIS is reviewed. Along with general accounts of the technique and the pressure cells used, examples of science carried out in this field are given. (author)

  4. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... 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 ask for your readings. Blood Pressure Severity and ...

  5. Mediator-Generated Pressure Tactics (United States)

    Byrnes, Joseph F.


    Two examples of bluff pressures (as opposed to real pressures) used by mediators to effect contract settlements are presented, along with advice to negotiators on avoiding or minimizing such tactics. (Author/IRT)

  6. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Clinical Trials What Are Clinical Trials? Children & Clinical Studies NHLBI ... providers diagnose high blood pressure when blood pressure readings are consistently 140/90 mmHg or above. Confirming High Blood ...

  7. Diagnosis of High Blood Pressure (United States)

    ... Clinical Trials What Are Clinical Trials? Children & Clinical Studies NHLBI ... providers diagnose high blood pressure when blood pressure readings are consistently 140/90 mmHg or above. Confirming High Blood ...

  8. High Blood Pressure in Pregnancy (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 ...

  9. Shielding Idiosyncrasy from Isomorphic Pressures

    DEFF Research Database (Denmark)

    Alvarez, José Luis; Mazza, Carmelo; Strandgaard Pedersen, Jesper;


    Moretti (Italy) and Lars vonTrier (Denmark). We argue that in a cinemafield, artistic pressures for distinctivenessalong with business pressures for profitsdrive filmmakers' quest for optimaldistinctiveness. This quest seeks bothexclusive, unique style and inclusive,audience-appealing artwork with...

  10. Genes That Influence Blood Pressure (United States)

    ... Research Matters NIH Research Matters September 26, 2011 Genes that Influence Blood Pressure In one of the ... 16 previously unknown variations. Six were found in genes already suspected of regulating blood pressure. The remaining ...


    Directory of Open Access Journals (Sweden)

    Retno Widiyanthi


    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Intracranial pressure is total of pressure that is produced by brain, blood, and cerebrospinal fluid/CSF in the tight cranial space. As a respon to intracranial pressure increasing, compensation begin by movement of CSF from ventricle to cerebral subarachnoidal space, and increase the absorption of CSF. Increasing of ICP usually caused by increasing of brain volume (cerebral oedem, blood (intracranial bleeding, space occupying lesion, or CSF (hidrocephalus. Indication in ICP monitoring can be seen from : neurological criteria, abnormal CT-scan result when admission, normal CT-scan result, but had more two risk factors. According to the procedure that must be done, there are two methods in ICP monitoring: invasive ICP monitoring methodes and non-invasive measuring method. Increasing of ICP will decrease the compliance of brain, pulsation of artery more clearly, and the component of vein is lost. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  12. Unibody Composite Pressurized Structure (United States)

    Rufer, Markus; Conger, Robert; Bauer, Thomas; Newman, John


    An integrated, generic unibody composite pressurized structure (UCPS) combined with a positive expulsion device (PED), consisting of an elastomeric bladder for monopropellant hydrazine, has been quasi-standardized for spacecraft use. The combination functions as an all-composite, non-metallic, propellant tank with bladder. The integrated UCPS combines several previous innovations - specifically, the linerless, all-composite cryogenic tank technology; all-composite boss; resin formulation; and integrated stringer system. The innovation combines the UCPS with an integrated propellant management device (PMD), the PED or bladder, to create an entirely unique system for in-space use. The UCPS is a pressure vessel that incorporates skirts, stringers, and other structures so that it is both an in-space hydrazine tank, and also a structural support system for a spacecraft in a single, all-composite unit. This innovation builds on the progress in the development of a previous SBIR (Small Business Innovation Research) Phase I with Glenn Research Center and an SBIR III with Johnson Space Center that included the fabrication of two 42-in. (˜107-cm) diameter all-composite cryogenic (LOX and liquid methane) UCPS test tanks for a lunar lander. This Phase II provides hydra zine compatibility testing of the elastomeric bladder, a see-through PED to validate the expulsion process and model, and a complete UCPS-based PED with stringers and skirts that will be used to conduct initial qualification and expulsion tests. This extends the UCPS technology to include hydrazine-based, in-space pro - pulsion applications and can also be used for electric propulsion. This innovation creates a system that, in comparison to the traditional approach, is lower in weight, cost, volume, and production time; is stronger; and is capable of much higher pressures. It also has fewer failure modes, and is applicable to both chemical and electric propulsion systems.

  13. Barotrauma: Tooth Under Pressure. (United States)

    Kumar, Satheesh; Kumar, Preeti Satheesh; John, Jins; Patel, Ruchi


    With the growing number of air passengers, flight attendants, leisure pilots, as well as military and airline pilots, dentists may encounter physiological and pathological phenomena precipitated by high altitude. With the introduction of the self-contained breathing apparatus (SCUBA), many of these manifestations caused by changes in atmospheric pressure were reported in association with diving as well. Limited literature exists on this subject. Hence, this article aims to review literature concerning the classification, etiology and manifestations of barodontalgia, as well as important clinical considerations for its management. PMID:26697664

  14. Pressure pain sensitivity

    DEFF Research Database (Denmark)

    Bergmann, Natasha; Ballegaard, Søren; Holmager, Pernille;


    induce hyperalgesia.The aim of the present study was to evaluate hyperalgesia by pressure pain sensitivity (PPS) in patients with IHD, and compare PPS to questionnaires measuring depressive symptoms, reduced psychological wellbeing, and QOL as markers of stress. Design. A cross-sectional study of 361...... subjects with IHD. Methods. PPS was measured on the sternum, and compared to the questionnaires: Clinical stress symptoms score (CSS), Major Depression Inventory (MDI), WHO-5 Wellbeing Index, and SF-36 QOL score. Results. PPS correlated to CSS (r = 0.20, p <0.001), MDI (r = 0.14, p = 0.02), SF-36 mental...

  15. Saltstone Osmotic Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Ralph L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, Kenneth L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRN


    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR- 2013-0004.

  16. Murata - A Pressure Sensor Based Blood Pressure : Preliminary Reliability Study


    Nummelin, Elina


    The purpose of the study was to determine the reliability of a blood pressure sensor developed by Murata as a blood pressure monitoring tool compared to an automatic blood pressure monitor, Omron M6. Blood pressure is one of the principal vital signs and is utilized for monitoring both short-term and long-term health of the cardiovascular system and thereby the health of the patient. Therefore there is a need for a non-invasive blood pressure monitor for accurate, continuous and comfortab...

  17. Diagnosis of High Blood Pressure

    Medline Plus

    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 ...

  18. Gas Pressure-Drop Experiment (United States)

    Luyben, William L.; Tuzla, Kemal


    Most chemical engineering undergraduate laboratories have fluid mechanics experiments in which pressure drops through pipes are measured over a range of Reynolds numbers. The standard fluid is liquid water, which is essentially incompressible. Since density is constant, pressure drop does not depend on the pressure in the pipe. In addition, flow…

  19. Instrument measures dynamic pressure fluctuations (United States)

    Coats, J. W.; Penko, P. E.; Reshotko, M.


    Pressure probe instrument, incorporating "infinite line" principle, can be used to remotely measure dynamic pressure fluctuations in hot high-pressure environemnts too severe for sensors. System is designed and can be utilized for measurements in core of operating turbofan engine.

  20. 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 ...

  1. Living with High Blood Pressure (United States)

    ... from the NHLBI on Twitter. Living With High Blood Pressure If you have high blood pressure, the best thing to do is to talk ... care provider and take steps to control your blood pressure by making healthy lifestyle changes and taking medications, ...

  2. Pressure Safety: Advanced Live 11459

    Energy Technology Data Exchange (ETDEWEB)

    Glass, George [Los Alamos National Laboratory


    Many Los Alamos National Laboratory (LANL) operations use pressure equipment and systems. Failure to follow proper procedures when designing or operating pressure systems can result in injuries to personnel and damage to equipment and/or the environment. This manual presents an overview of the requirements and recommendations that address the safe design and operation of pressure systems at LANL.

  3. Dual rate pressure relief valve (United States)

    Steeneken, J.


    Pressure relief valve vents at a slow bleed rate at one pressure level and at a higher bleed rate at a higher pressure level. The value housing contains a sleeve, inlet port, outlet port, an orifice, a ball and seat arrangement, and a belleville spring diaphragm.

  4. Photonic crystal fiber pressure sensor (United States)

    Fávero, F. C.; Quintero, S. M. M.; Silva, V. V.; Martelli, C.; Braga, Arthur M. B.; Carvalho, Isabel C. S.; Llerena, Roberth W. A.


    A high sensitivity optical fiber pressure sensor based on a modal interferometer with high birefringence photonic fiber is proposed and demonstrated. The sensor dependence with hydrostatic pressure is evaluated both numerically and experimentally. The measured pressure sensitivity at room temperature is found to be 3.36 nmMPa-1.

  5. The Myth of Peer Pressure. (United States)

    Ungar, Michael T.


    The construct of peer pressure was examined as part of a qualitative study of the determinants of mental health for 41 high-risk adolescents. While the concept of peer pressure enables adults to explain youths' troubling behaviors, content analysis of the participants' accounts of their lives reveals peer pressure to be a myth. (Author/MKA)

  6. Pressure transients in pipeline systems

    DEFF Research Database (Denmark)

    Voigt, Kristian


    This text is to give an overview of the necessary background to do investigation of pressure transients via simulations. It will describe briefly the Method of Characteristics which is the defacto standard for simulating pressure transients. Much of the text has been adopted from the book Pressur...

  7. Experimental research on pressure loss of rotary pressure exchanger (United States)

    Jiao, L.; Shi, Y.; Liu, Z. C.; Li, L.; Feng, Z. M.; Zhao, C. F.; Wei, Y.


    In order to research the phenomenon ‘Pressure Loss’ of Rotary Pressure Exchanger when it worked in a certain working condition, such as pressure and flow, two different series of experiments were performed respectively in the same experimental apparatus. One is to set pressure as constant when flow is changeable, the other one is to set flow as constant when pressure is changeable. Then, the curves and tables depicting the relationship between the pressure loss rate and working conditions were illustrated. Results from the curves and tables show that flow and pressure has an impact on pressure loss, and the relationship present some of regularity. According to the regularity, an empirical formula which can be used to approximately predict the magnitude of pressure loss for subsequent engineering application was provided by regression analysis on the basis of experimental data. Meanwhile, a 3-Dimensional geometric model of passageway in rotary pressure exchanger were built to verify the accuracy, making a steady calculation on pressure field by Fluent. At last, the feasibility was verified in a field application in a desalination factory.

  8. Pressure polymerization of polyester (United States)

    Maurer, Charles J.; Shaw, Gordon; Smith, Vicky S.; Buelow, Steven J.; Tumas, William; Contreras, Veronica; Martinez, Ronald J.


    A process is disclosed for the preparation of a polyester polymer or polyester copolymer under superatmospheric pressure conditions in a pipe or tubular reaction under turbannular flow conditions. Reaction material having a glycol equivalents to carboxylic acid equivalents mole ratio of from 1.0:1 to 1.2:1, together with a superatmospheric dense gaseous medium are fed co-currently to the reactor. Dicarboxylic acid and/or diol raw materials may be injected into any of the reaction zones in the process during operation to achieve the overall desired mole ratio balance. The process operates at temperatures of from about C. to about C., with turbannular flow achieved before the polymer product and gas exit the reactor process. The pressure in the reaction zones can be in the range from 15 psia to 2500 psia. A polymer product having a DP of a greater than 40, more preferably at least about 70, is achieved by the transfer of water from the reacting material polymer melt to the gaseous medium in the reactor.

  9. Clinical management of pressure ulcers. (United States)

    Thomas, David R


    Pressure ulcers are chronic and difficult to heal. Pressure-reducing devices are clearly superior to a standard hospital mattress in preventing pressure ulcers, but only limited evidence and clinical intuition supports pressure-reducing devices in improving the healing rate of pressure ulcers. Local wound treatment should aim at maintaining a moist wound environment. The choice of a particular dressing depends on wound characteristics, such as the amount of exudate, dead space, or wound location. Nutritional status should be addressed as a process of good care. Debridement may improve time to a clean wound bed, but no clearly superior approach has been demonstrated. PMID:23571035


    Directory of Open Access Journals (Sweden)

    M. F. VALIM


    Full Text Available

    Blood pressure is the force of blood against artery walls. It is measured in millimeters of mercury (mm Hg and recorded as two numbers: systolic pressure (as the heart contracts over diastolic pressure (as the heart relaxes between beats. High blood pressure (hypertension is defined as chronically elevated high blood pressure, with systolic blood pressure (SBP of 140 mm Hg or greater, and diastolic blood pressure (DBP of 90 mm Hg or greater. High blood pressure (HBP, smoking, abnormal blood lipid levels, obesity and diabetes are risk factors for coronary heart disease, the leading cause of death in the US. Lifestyle modifications such as engaging in regular physical activity, quitting smoking and eating a healthy diet (limiting intake of saturated fat and sodium and increasing consumption of fiber, fruits and vegetables are advocated for the prevention, treatment, and control of HBP. As multiple factors influence blood pressure, the effects of each factor are typically modest, particularly in normotensive subjects, yet the combined effects can be substantial. Nutrition plays an important role in influencing blood pressure. Orange juice should be included as part of any low sodium diet and/or any blood pressure reducing eating plan, as it is sodium free, fat-free and can help meet recommended levels of potassium intake that may contribute to lower BP.

  11. BWR zero pressure containment

    International Nuclear Information System (INIS)

    This patent describes the operation of a nuclear reactor system, the system including a containment defining a drywall space wherein a nuclear reactor is disposed, there being a suppression pool in the containment with the suppression pool having a wetwell space above a level of the pool to which an non-condensable gases entering the suppression pool can vent. It comprises: continuously exhausting the wetwell space to remove gas mixture therefrom while admitting inflow of air from an atmospheric source thereof to the wetwell during normal operation by blocking off the inflow during a loss-of-coolant-accident whenever a pressure in the wetwell space is above a predetermined value, and subjecting the gas subsequent to its removal from the wetwell to a treatment operation to separate any particulate material entrained therein from the gas mixture

  12. Effects of pressure waves (United States)


    Two parameters, side on overpressure and side on impulse loads, and their application to the determination of structural damage to buildings and vehicles in the vicinity of an explosion are investigated. Special consideration was given to what constitutes damage and what level of damage is acceptable. Solutions were sorted through the examination of glass breakage, curve fit to bomb damage, overturning of marginal structures (buses, trucks, mobile homes) subject to toppling, and initiation of yielding in either beam or plate structural components. Three different empirical pressure versus impulse diagrams were presented - the first is for minor structural damage involving wrenched joints and partitions, the second is for major damage structural damage with load bearing members at least partially destroyed, and the third is for 50% to 75% of the building demolished. General guidelines were obtained from the results when the accurate structural details are unknown.

  13. From Pressures to Impacts

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky


    Life cycle assessment (LCA) has been developed as a tool for assessment of the environmental impacts which are caused by the pressures from products or systems, viewed in a life cycle perspective, i.e. covering all stages of the life cycle of the product or system from the extraction of raw...... materials over manufacture or construction through use to disposal or decommissioning and recycling. It is a holistic tool in the sense that it models all relevant environmental impacts from the global (like climate change and ozone depletion) to the local (like land use) and also the loss of resources. The...... is defined, Inventory analysis where data for the physical flows to and from all processes in the life cycle is collected and related to the functional unit, Impact assessment, where the physical flows are translated into impacts on the environment and resource base, and Interpretation where the...

  14. Pressure vessel design manual

    Energy Technology Data Exchange (ETDEWEB)

    Moss, D.R.


    The first section of the book covers types of loadings, failures, and stress theories, and how they apply to pressure vessels. The book delineates the procedures for designing typical components as well as those for designing large openings in cylindrical shells, ring girders, davits, platforms, bins and elevated tanks. The techniques for designing conical transitions, cone-cylinder intersections, intermediate heads, flat heads, and spherically dished covers are also described. The book covers the design of vessel supports subject to wind and seismic loads and one section is devoted to the five major ways of analyzing loads on shells and heads. Each procedure is detailed enough to size all welds, bolts, and plate thicknesses and to determine actual stresses.

  15. Estimation of vapour pressure and partial pressure of subliming compounds by low-pressure thermogravimetry

    Indian Academy of Sciences (India)

    G V Kunte; Ujwala Ail; P K Ajikumar; A K Tyagi; S A Shivashankar; A M Umarji


    A method for the estimation of vapour pressure and partial pressure of subliming compounds under reduced pressure, using rising temperature thermogravimetry, is described in this paper. The method is based on our recently developed procedure to estimate the vapour pressure from ambient pressure thermogravimetric data using Langmuir equation. Using benzoic acid as the calibration standard, vapour pressure–temperature curves are calculated at 80, 160 and 1000 mbar for salicylic acid and vanadyl bis-2,4-pentanedionate, a precursor used for chemical vapour deposition of vanadium oxides. Using a modification of the Langmuir equation, the partial pressure of these materials at different total pressures is also determined as a function of temperature. Such data can be useful for the deposition of multi-metal oxide thin films or doped thin films by chemical vapour deposition (CVD).

  16. Multilayer Composite Pressure Vessels (United States)

    DeLay, Tom


    A method has been devised to enable the fabrication of lightweight pressure vessels from multilayer composite materials. This method is related to, but not the same as, the method described in gMaking a Metal- Lined Composite-Overwrapped Pressure Vessel h (MFS-31814), NASA Tech Briefs, Vol. 29, No. 3 (March 2005), page 59. The method is flexible in that it poses no major impediment to changes in tank design and is applicable to a wide range of tank sizes. The figure depicts a finished tank fabricated by this method, showing layers added at various stages of the fabrication process. In the first step of the process, a mandrel that defines the size and shape of the interior of the tank is machined from a polyurethane foam or other suitable lightweight tooling material. The mandrel is outfitted with metallic end fittings on a shaft. Each end fitting includes an outer flange that has a small step to accommodate a thin layer of graphite/epoxy or other suitable composite material. The outer surface of the mandrel (but not the fittings) is covered with a suitable release material. The composite material is filament- wound so as to cover the entire surface of the mandrel from the step on one end fitting to the step on the other end fitting. The composite material is then cured in place. The entire workpiece is cut in half in a plane perpendicular to the axis of symmetry at its mid-length point, yielding two composite-material half shells, each containing half of the foam mandrel. The halves of the mandrel are removed from within the composite shells, then the shells are reassembled and bonded together with a belly band of cured composite material. The resulting composite shell becomes a mandrel for the subsequent steps of the fabrication process and remains inside the final tank. The outer surface of the composite shell is covered with a layer of material designed to be impermeable by the pressurized fluid to be contained in the tank. A second step on the outer flange of

  17. Steam Oxidation at High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL; Carney, Casey [URS


    A first high pressure test was completed: 293 hr at 267 bar and 670{degrees}C; A parallel 1 bar test was done for comparison; Mass gains were higher for all alloys at 267 bar than at 1 bar; Longer term exposures, over a range of temperatures and pressures, are planned to provide information as to the commercial implications of pressure effects; The planned tests are at a higher combination of temperatures and pressures than in the existing literature. A comparison was made with longer-term literature data: The short term exposures are largely consistent with the longer-term corrosion literature; Ferritic steels--no consistent pressure effect; Austenitic steels--fine grain alloys less able to maintain protective chromia scale as pressure increases; Ni-base alloys--more mass gains above 105 bar than below. Not based on many data points.

  18. Pressure sensors for petroleum wells

    International Nuclear Information System (INIS)

    A patent is claimed for a pressure sensor to be used in petroleum wells. Measurements can be performed under extreme temperature and pressure conditions. The system consists of a cell, containing an extensometric circuit, placed in a container and in contact with the pressure to be measured. The cell is formed by two sapphire half-shells. Their crystallographic orientation is chosen in order to obtain isotropy of stresses. The sensor is nearly independent from temperature fluctuations

  19. Do professionals choke under pressure?


    Dohmen, Thomas


    High rewards or the threat of severe punishment do not only provide incentives to exert high levels of effort but also create pressure. Such pressure can cause paradoxical performance effects, namely performance decrements despite strong incentives and high motivation. By analyzing the performance of professional football players on a well-defined task, namely to score on a penalty kick, the paper provides empirical evidence for the existence of such detrimental incentive effects. Two pressur...

  20. Neutron scattering at high pressure


    Mcwhan, D.B.


    The techniques to do elastic and inelastic neutron scattering at steady-state and pulsed sources are reviewed. The pressure cells available at most neutron scattering centres are capable of reaching pressures of the order of 5 GPa (50 kbar), and attempts to reach 10 GPa have been made. For elastic scattering, a comparison is made between neutron scattering and X-ray scattering at high pressure using rotating anode or synchrotron sources.

  1. Pressures Detector Calibration and Measurement

    CERN Document Server

    Kumara, I Made Gita


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

  2. Pressure on Yukos growing

    International Nuclear Information System (INIS)

    The fate of the Russian oil concern Yukos seems to be sealed. The former rising star of the Russian energy firmament seems to be dying under the pressure of local state administration. Tax arrears, the fact that the owner Mikhail Khodorkovsky was jailed and the company placed under forced administration reflects the conflict between business and political interests in Russia. And the conflict also has an impact on Slovakia. In the portfolio of Yukos Finance, the Dutch subsidiary of Yukos, are assets that are very attractive for Russian oil concerns. One of them is the Slovak operator of the Druzba pipeline, Transpetrol. Yukos Finance owns 49% of the company's shares. Last year, the company signed a contract with the Russian oil company Russneft on the sale of the stake for 103 mil. USD. According to a contract signed in 2002 that stipulated the conditions under which the Slovak state sold the Transpetrol shares to Yukos for the next 5 years such a step has to be approved by the Ministry of Economy. The Dutch company can also sell the shares without such an approval but then it has to pay a penalty fine. In such a case Slovakia would get 50% of the original amount, i.e. 37 mil. USD. (author)

  3. Reactor pressure vessel cooling device

    International Nuclear Information System (INIS)

    A spray pipeline for the head of a pressure vessel is connected to a spray for the pressure vessel head of the reactor pressure vessel. The pipeline is equipped with a spray flow rate control valve for controlling the flow rate of spray jetted from the head spray to the inside of the reactor and a thermometer for spray water. A reactor pressure vessel cooling and controlling portion intakes temperature signals sent from a thermometer for the head of the pressure vessel, a thermometer for the flange of the pressure vessel and a thermometer for the body of the pressure vessel, and a thermometer for spray water. Then, it outputs restriction signal for the opening degree of the spray flow rate control valve to restrict the spray water flow rate within an appropriate range when the difference between the temperature of each portion of the pressure vessel and the temperature of spray water is increased to greater than an allowable temperature difference. With such procedures, spray operation for the head of the pressure vessel can be conducted not only upon emergency but also during reactor cooling operation. (I.N.)

  4. Night time blood pressure dip

    Institute of Scientific and Technical Information of China (English)

    Dennis; Bloomfield; Alex; Park


    The advent of ambulatory blood pressure monitoring permitted examination of blood pressures during sleep and recognition of the associated circadian fall in pressure during this period. The fall in pressure,called the "dip",is defined as the difference between daytime mean systolic pressure and nighttime mean systolic pressure expressed as a percentage of the day value. Ten percent to 20% is considered normal. Dips less than 10%,referred to as blunted or absent,have been considered as predicting an adverse cardiovascular event. This view and the broader concept that white coat hypertension itself is a forerunner of essential hypertension is disputable. This editorial questions whether mean arterial pressures over many hours accurately represent the systolic load,whether nighttime dipping varies from measure to measure or is a fixed phenomenon,whether the abrupt morning pressure rise is a risk factor or whether none of these issues are as important as the actual night time systolic blood pressure itself. The paper discusses the difference between medicated and nonmedicated white coat hypertensives in regard to the cardiovascular risk and suggests that further work is necessary to consider whether the quality and duration of sleep are important factors.

  5. Risk Factors for High Blood Pressure (United States)

    ... the NHLBI on Twitter. Risk Factors for High Blood Pressure Anyone can develop high blood pressure; however, age, ... can increase your risk for developing high blood pressure. Age Blood pressure tends to rise with age. About 65 ...

  6. Healthy Blood Pressure: "It's Worth the Effort!" (United States)

    ... please turn Javascript on. Special Section: Healthy Blood Pressure Healthy Blood Pressure: "It's worth the effort!" Past Issues / Winter 2010 ... Numbers: What They Mean / Treatment: Types of Blood Pressure Medications / Healthy Blood Pressure: "It's worth the effort!" / Keep the Beat ...

  7. High Blood Pressure and Kidney Disease (United States)

    ... to Remember Clinical Trials What is high blood pressure? Blood pressure is the force of blood pushing against ... filtering units called nephrons. [ Top ] How does high blood pressure affect the kidneys? High blood pressure can damage ...

  8. High Blood Pressure: Medicines to Help You (United States)

    ... Consumers Consumer Information by Audience For Women High Blood Pressure--Medicines to Help You Share Tweet Linkedin Pin ... is your pressure when your heart relaxes ( diastolic pressure ). High Blood Pressure Medicines Use this guide to help you ...

  9. High Blood Pressure (Hypertension) (For Parents) (United States)

    ... lead an active, normal life. What Is Blood Pressure? Blood pressure is the force that blood puts on ... and medications. continue Long-Term Effects of High Blood Pressure When someone has high blood pressure, the heart ...

  10. Pressure sensor apparatus for indicating pressure in the body

    International Nuclear Information System (INIS)

    A novel pressure sensor for indicating pressure in the body cavities of humans or animals is described in detail. The pressure sensor apparatus is relatively small and is easily implantable. It consists of a radioactive source (e.g. Pr-145, C-14, Ni-63, Sr-90 and Am-241) and associated radiation shielding and a bellows. The pressure acting upon the sensing tambour causes the bellows to expand and contract. This is turn causes the radiation shielding to move and changes in pressure can then be monitored external to the body using a conventional nuclear detector. The bellows is made of resilient material (e.g. gold plated nickel) and has a wall thickness of approximately 0.0003 inches. The apparatus is essentially insensitive to temperature variations. (U.K.)

  11. Neural Network Burst Pressure Prediction in Composite Overwrapped Pressure Vessels (United States)

    Hill, Eric v. K.; Dion, Seth-Andrew T.; Karl, Justin O.; Spivey, Nicholas S.; Walker, James L., II


    Acoustic emission data were collected during the hydroburst testing of eleven 15 inch diameter filament wound composite overwrapped pressure vessels. A neural network burst pressure prediction was generated from the resulting AE amplitude data. The bottles shared commonality of graphite fiber, epoxy resin, and cure time. Individual bottles varied by cure mode (rotisserie versus static oven curing), types of inflicted damage, temperature of the pressurant, and pressurization scheme. Three categorical variables were selected to represent undamaged bottles, impact damaged bottles, and bottles with lacerated hoop fibers. This categorization along with the removal of the AE data from the disbonding noise between the aluminum liner and the composite overwrap allowed the prediction of burst pressures in all three sets of bottles using a single backpropagation neural network. Here the worst case error was 3.38 percent.

  12. High pressure experimental water loop

    International Nuclear Information System (INIS)

    A high pressure experimental water loop has been made for studying the detection and evolution of cladding failure in a pressurized reactor. The loop has been designed for a maximum temperature of 360 deg. C, a maximum of 160 kg/cm2 and flow rates up to 5 m3/h. The entire loop consists of several parts: a main circuit with a canned rotor circulation pump, steam pressurizer, heating tubes, two hydro-cyclones (one de-gasser and one decanter) and one tubular heat exchanger; a continuous purification loop, connected in parallel, comprising pressure reducing valves and resin pots which also allow studies of the stability of resins under pressure, temperature and radiation; following the gas separator is a gas loop for studying the recombination of the radiolytic gases in the steam phase. The preceding circuits, as well as others, return to a low pressure storage circuit. The cold water of the low pressure storage flask is continuously reintroduced into the high pressure main circuit by means of a return pump at a maximum head of 160 kg /cm2, and adjusted to the pressurizer level. This loop is also a testing bench for the tight high pressure apparatus. The circulating pump and the connecting flanges (Oak Ridge type) are water-tight. The feed pump and the pressure reducing valves are not; the un-tight ones have a system of leak recovery. To permanently check the tightness the circuit has been fitted with a leak detection system (similar to the HRT one). (author)

  13. Pressurized Lunar Rover (PLR) (United States)

    Creel, Kenneth; Frampton, Jeffrey; Honaker, David; McClure, Kerry; Zeinali, Mazyar; Bhardwaj, Manoj; Bulsara, Vatsal; Kokan, David; Shariff, Shaun; Svarverud, Eric

    The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a nominal crew of four, support two 28-hour EVA's, and in case of emergency, support a crew of six when near the lunar base. A nominal speed of ten km/hr and capability of towing a trailer with a mass of two mt are required. Two preliminary designs have been developed by two independent student teams. The PLR 1 design proposes a seven meter long cylindrical main vehicle and a trailer which houses the power and heat rejection systems. The main vehicle carries the astronauts, life support systems, navigation and communication systems, lighting, robotic arms, tools, and equipment for exploratory experiments. The rover uses a simple mobility system with six wheels on the main vehicle and two on the trailer. The nonpressurized trailer contains a modular radioisotope thermoelectric generator (RTG) supplying 6.5 kW continuous power. A secondary energy storage for short-term peak power needs is provided by a bank of lithium-sulfur dioxide batteries. The life support system is partly a regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center allowing the center to be used as a safe haven during solar flares. The PLR 1 has a total mass of 6197 kg. It has a top speed of 18 km/hr and is capable of towing three metric tons, in addition to the RTG trailer. The PLR 2 configuration consists of two four-meter diameter, cylindrical hulls which are passively connected by a flexible passageway, resulting in the overall vehicle length of 11 m. The vehicle is driven by eight independently suspended wheels. The dual-cylinder concept allows articulated as well as double

  14. Solvation pressure as real pressure: I. Ethanol and starch under negative pressure

    CERN Document Server

    Uden, N W A V; Faux, D A; Tanczos, A C; Howlin, B; Dunstan, D J


    The reality of the solvation pressure generated by the cohesive energy density of liquids is demonstrated by three methods. Firstly, the Raman spectrum of ethanol as a function of cohesive energy density (solvation pressure) in ethanol-water and ethanol-chloroform mixtures is compared with the Raman spectrum of pure ethanol under external hydrostatic pressure and the solvation pressure and hydrostatic pressure are found to be equivalent for some transitions. Secondly, the bond lengths of ethanol are calculated by molecular dynamics modelling for liquid ethanol under pressure and for ethanol vapour. The difference in bond lengths between vapour and liquid are found to be equivalent to the solvation pressure for the C-H sub 3 , C-H sub 2 and O-H bond lengths, with discrepancies for the C-C and C-O bond lengths. Thirdly, the pressure-induced gelation of potato starch is measured in pure water and in mixtures of water and ethanol. The phase transition pressure varies in accordance with the change in solvation pre...

  15. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... does not, you should 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 the office and ...

  16. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

  17. High pressure engineering and technology

    International Nuclear Information System (INIS)

    This book contains 10 papers. Some of the titles are: Control of vibration in high pressure piping systems; Hazards and safeguards of high pressure hydraulic fatigue testing; Load, stress and fatigue analysis of threaded end closures; Application of fatigue crack growth to an isostatic press; and Time dependent failure in high strength steels for autoclave service

  18. Diabetes and blood pressure (image) (United States)

    People with diabetes have a higher risk for heart attacks and strokes. Your doctor or nurse should check your blood pressure ... People with diabetes have a higher risk for heart attacks and strokes. Your doctor or nurse should check your blood pressure ...

  19. On pressure rise in rockets

    Directory of Open Access Journals (Sweden)

    S. K. Gupta


    Full Text Available The phenomenon of pressure rise in rockets has been discussed on the basis of r=CP/Sup/n as the law of burning. An explicit expression for the chamber pressure at any instant has been derived and illustrated by a table and a graph.

  20. High Pressure Effects on Superconductivity


    Lorenz, B.; Chu, C. W.


    The review is devoted to a discussion of the effects of high pressure imposed on superconducting materials. Low-temperature superconductors, high-temperature superconducting cuprates, and some unconventional superconducting compounds are investigated. Experimental as well as theoretical results regarding the pressure effects on Tc and other interesting properties are summarized.

  1. Pressure drop in contraction flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    This note is a supplement to Dynamic of Polymeric Liquids (DPL) page 178. DPL gives an equation for the pressure drop in a tapered (and circular) contraction, valid only at low angles. Here the general definition of contraction flow (the Bagley correction) and a more general method to find the...... pressure drop in a contraction are given....

  2. Helping Teens Resist Sexual Pressure (United States)

    ... perils of experience that comes too early. “When young people have sex before they’re ready, they usually end up ... Sexual Pressure “The pressure on teenagers to have sex is enormous,” says Denver pediatrician Dr. Ron Eagar, adding that kids often feel as if they’re caught in ...

  3. 26 CFR 1.611-2 - Rules applicable to mines, oil and gas wells, and other natural deposits. (United States)


    ... subsequent improvements in methods of extraction and treatment of the mineral product. The district director... information having a probable bearing on the oil and gas content; information with respect to edge water, water drive, bottom hole pressures, oil-gas ratio, porosity of reservoir rock, percentage of...

  4. Piezoelectric enhancement under negative pressure. (United States)

    Kvasov, Alexander; McGilly, Leo J; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S; Sluka, Tomas; Tagantsev, Alexander K; Setter, Nava


    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones. PMID:27396411

  5. Wrinkling of Pressurized Elastic Shells

    KAUST Repository

    Vella, Dominic


    We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells are subject to a wrinkling instability. We study wrinkling in depth, presenting scaling laws for the critical indentation at which wrinkling occurs and the number of wrinkles formed in terms of the internal pressurization and material properties of the shell. These results are validated by numerical simulations. We show that the evolution of the wrinkle length with increasing indentation can be understood for highly pressurized shells from membrane theory. These results suggest that the position and number of wrinkles may be used in combination to give simple methods for the estimation of the mechanical properties of highly pressurized shells. © 2011 American Physical Society.

  6. Pressurized waterproof case electronic device

    KAUST Repository

    Berumen, Michael L.


    A pressurized waterproof case for an electronic device is particularly adapted for fluid-tight containment and operation of a touch-screen electronic device or the like therein at some appreciable water depth. In one example, the case may be formed as an enclosure having an open top panel or face covered by a flexible, transparent membrane or the like for the operation of the touchscreen device within the case. A pressurizing system is provided for the case to pressurize the case and the electronic device therein to slightly greater than ambient in order to prevent the external water pressure from bearing against the transparent membrane and pressing it against the touch screen, thereby precluding operation of the touch screen device within the case. The pressurizing system may include a small gas cartridge or may be provided from an external source.

  7. Pressure transient in liquid lines

    International Nuclear Information System (INIS)

    The pressure surge that results from a step change of flow in liquid pipelines, commonly known as water hammer, was analyzed by an eigenfunction method. A differential-integral Pressure wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless transmission number K. The pressure surge condition, which is mathematically singular, was used in the solution procedure. The exact solutions from numerical calculation of the differential-integral equation provide a complete Pressure transient in the pipe. The problems are also calculated With the general-purpose computer code COMMIX, which solves the exact mass conservation equation and Navier-Stokes equations. These solutions were compared with published experimental results, and agreement was good. The effect of turbulence on the pressure transient is discussed in the light of COMMIX calculational results

  8. High-pressure optical studies

    International Nuclear Information System (INIS)

    High pressure experimentation may concern intrinsically high pressure phenomena, or it may be used to gain a better understanding of states or processes at one atmosphere. The latter application is probably more prevelant in condensed matter physics. Under this second rubric one may either use high pressure to perturb various electronic energy levels and from this pressure tuning characterize states or processes, or one can use pressure to change a macroscopic parameter in a controlled way, then measure the effect on some molecular property. In this paper, the pressure tuning aspect is emphasized, with a lesser discussion of macroscopic - molecular relationships. In rare earth chelates the efficiency of 4f-4f emission of the rare earth is controlled by the feeding from the singlet and triplet levels of the organic ligand. These ligand levels can be strongly shifted by pressure. A study of the effect of pressure on the emission efficiency permits one to understand the effect of ligand modification at one atmosphere. Photochromic crystals change color upon irradiation due to occupation of a metastable ground state. In thermochromic crystals, raising the temperature accomplishes the same results. For a group of molecular crystals (anils) at high pressure, the metastable state can be occupied at room temperature. The relative displacement of the energy levels at high pressure also inhibits the optical process. Effects on luminescence intensity are shown to be consistent. In the area of microscopic - molecular relationships, the effect of viscosity and dielectric properties on rates of non-radiative (thermal) and radiative emission, and on peak energy for luminescence is demonstrated. For systems which can emit from either of two excited states depending on the interaction with the environment, the effect of rigidity of the medium on the rate of rearrangement of the excited state is shown

  9. High pressure effects on fruits and vegetables


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


    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 treatment can be used for product modification through pressure gelatinization of starch and pressure denaturation of proteins. Key pressure–thermal treatment effects on vitamin, enzymes, flavor, co...

  10. Pressure sensor for sealed containers (United States)

    Hodges, Franklin R.


    A magnetic pressure sensor for sensing a pressure change inside a sealed container. The sensor includes a sealed deformable vessel having a first end attachable to an interior surface of the sealed container, and a second end. A magnet mounted to the vessel second end defining a distance away from the container surface provides an externally detectable magnetic field. A pressure change inside the sealed container causes deformation of the vessel changing the distance of the magnet away from the container surface, and thus the detectable intensity of the magnetic field.

  11. Self pressuring HTP feed systems

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, J.


    Hydrogen peroxide tanks can be pressurized with decomposed HTP (high test hydrogen peroxide) originating in the tank itself. In rocketry, this offers the advantage of eliminating bulky and heavy inert gas storage. Several prototype self-pressurizing HTP systems have recently been designed and tested. Both a differential piston tank and a small gas-driven pump have been tried to obtain the pressure boost needed for flow through a gas generator and back to the tank. Results include terrestrial maneuvering tests of a prototype microsatellite, including warm gas attitude control jets.

  12. Measurement of fast transient pressures

    International Nuclear Information System (INIS)

    The accuracy, reliability and sensitivity of a pressure transducers define its principal static characteristics. When the quantity measured varies with time, the measurement carries a dynamic error and a delay depending on the frequency of this variation. Hence, when fast pressure changes in a fluid have to be determined, different kinds of pressure transducers can be used depending on their inherent dynamic characteristics which must be compared with those of the transient phenomenon to be analysed. The text describes the pressure transducers generally employed in industry for analysing such phenomenon and gives two practical applications developed in the EDF: the first submits the measurements and results of pump cavitation tests carried out at the Vitry II EDF power station; the second deals with hammer blows particularly noticed in nuclear power stations and required the use of transducers of exceptionally high performance such as strain gauge transducers and piezoelectric transducers (response time within 1m sec.)

  13. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Budget, Planning, & Legislative Advisory Committees Contact Us FAQs Home » Health Information for the Public » Health Topics » High ... also may ask you to check readings at home or at other locations that have blood pressure ...

  14. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments ... stress, which can occur during the medical appointment, causes white coat hypertension. Rate This Content: NEXT >> Updated: ...

  15. All-optical pressure sensor

    DEFF Research Database (Denmark)


    The present invention relates to an all-optical pressure sensor comprising a waveguide accommodating a distributed Bragg reflector. Pressure sensing can then be provided by utilizing effective index modulation of the waveguide and detection of a wavelength shift of light reflected from the Bragg...... reflector. Sound sensing may also be provided thereby having an all-optical microphone. One embodiment of the invention relates to an optical pressure sensor comprising at least one outer membrane and a waveguide, the waveguide comprising at least one core for confining and guiding light,at least one...... distributed Bragg reflector located in said at least one core, and at least one inner deflecting element forming at least a part of the core,wherein the pressure sensor is configured such that the geometry and/or dimension of the at least one core is changed when the at least one outer membrane is submitted...

  16. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... are consistently higher than 120/80 mmHg. Your child’s blood pressure numbers are outside average numbers for children of the same age, gender, and height . Once your health care provider ...

  17. Reducing catalytic converter pressure loss

    Energy Technology Data Exchange (ETDEWEB)



    This article examines why approximately 30--40% of total exhaust-system pressure loss occurs in the catalytic converter and what can be done to reduce pressure loss. High exhaust-system backpressure is of concern in the design of power trains for passenger cars and trucks because it penalizes fuel economy and limits peak power. Pressure losses occur due to fluid shear and turning during turbulent flow in the converter headers and in entry separation and developing laminar-flow boundary layers within the substrate flow passages. Some of the loss mechanisms are coupled. For example, losses in the inlet header are influenced by the presence of the flow resistance of a downstream substrate. Conversely, the flow maldistribution and pressure loss of the substrate(s) depend on the design of the inlet header.

  18. Nonlinear opto-mechanical pressure

    CERN Document Server

    Conti, Claudio


    A transparent material exhibits ultra-fast optical nonlinearity and is subject to optical pressure if irradiated by a laser beam. However, the effect of nonlinearity on optical pressure is often overlooked, even if a nonlinear optical pressure may be potentially employed in many applications, as optical manipulation, biophysics, cavity optomechanics, quantum optics, optical tractors, and is relevant in fundamental problems as the Abraham-Minkoswky dilemma, or the Casimir effect. Here we show that an ultra-fast nonlinear polarization gives indeed a contribution to the optical pressure that also is negative in certain spectral ranges; the theoretical analysis is confirmed by first-principles simulations. An order of magnitude estimate shows that the effect can be observable by measuring the deflection of a membrane made by graphene.

  19. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics Atherosclerosis DASH Eating Plan Overweight and Obesity Smoking and Your Heart ...

  20. Cryogenic MEMS Pressure Sensor Project (United States)

    National Aeronautics and Space Administration — A directly immersible cryogenic MEMS pressure sensor will be developed. Each silicon die will contain a vacuum-reference and a tent-like membrane. Offsetting...

  1. Metal extrusion using hydrostatic pressures

    International Nuclear Information System (INIS)

    The main problems connected with the deformation of metals due to extrusion are described. A method is put forward for calculating the rational rate of percentage deformation in the case of bar extrusion using a cylindrical container; reference is made to previous work on extrusion using a hydrostatic pressure with or without back-pressure. An extrusion process is described using hydrostatic pressure, without back-pressure, and using the lubricant for transmitting the thrust. This process has been used for eight years by the C.E.A. for the extrusion of a very wide range of metals, from beryllium to uranium and including steels; it leads to excellent surface textures. A very fine crystallization can be obtained on extruded products when the rate of extrusion is very low. There appears to be nothing against the use of high extrusion rates using this method. (author)

  2. Very small ionization pressure gauge

    International Nuclear Information System (INIS)

    A very small ionization pressure gauge has been developed to operate in the pressure range 10-6 Torr to 100μ. A metal construction and external cooling fins result in a very rugged device with exceptionally small outgassing properties. The gauge also incorporates a replaceable filament-grid assembly on a single plug which allows the simple replacement of both the filament and the grid when needed

  3. Membrane Bioreactor With Pressure Cycle (United States)

    Efthymiou, George S.; Shuler, Michael L.


    Improved class of multilayer membrane bioreactors uses convention forced by differences in pressure to overcome some of diffusional limitations of prior bioreactors. In reactor of new class, flow of nutrient solution reduces adverse gradients of concentration, keeps cells supplied with fresh nutrient, and sweeps away products faster than diffusion alone. As result, overall yield and rate of reaction increased. Pressures in sweeping gas and nutrient alternated to force nutrient liquid into and out of biocatalyst layer through hyrophilic membrane.

  4. Hydraulic calculation of pressure pipes


    Mikhalev, M. A.


    In the present time there is only one classic method for hydraulic calculation of pressure pipes. In it fluid flow velocity and pipeline diameter are considered as given values.The paper proposes a procedure for physical modeling and hydraulic calculation of pressure pipes, based on the theory of similarity. Methods for obtaining similarity criteria from combinations of similarity numbers were discussed. Similarity numbers and criteria and criteria equations were defined.

  5. Radiation-resistant pressure transducers

    International Nuclear Information System (INIS)

    Full text : The sensitive element of vibrofrequency tensor converter (VTC) is an electromechanical resonator of string type with electrostatic excitation of longitudinal mechanical vibrations. The string is made from tensosensitive thread-like monocrystal n-Ge1-x Six (length 1-5 mm, diameter 8-12 mcm) with current outlet and strictly fixed by ends at plate or deformable surface (in elastic element) at 50 mcm apartheid. With increasing Si atomic percent in n-Ge1-x Six the converter tens sensitivity increases. There has been shown the scheme of pressure transducer which contains monocrystalline silicon membrane and string tens converter from thread-like monocrystal Ge-Si. Using method, when crystal position on membrane while it deforms by pressure, corresponds to free (uptight) state, allowed to obtain the maximum sensitivity in measurement of pressure fluctuation. The transducers of absolute and pressure differential of this type can be used in automated systems of life activity. The high sensitivity of string transducers to pressure exceeding 100 hertz/mm (water column) permits to use them in devices for measuring gas concentration. The combination of optical and deformation methods of measurements forms the basis of their operation. The pressure change occurs due to the fact that gas molecules absorbing the quanta of incident light, become at excited state and then excitation energy of their vibrational-rotatory degrees of freedom converts to the energy of translational motion of molecules, i.e. to heat appropriate to pressure increase. Using these tens converters of high pressure one can prevent the possible accidents on oil pipe-like Baku-Tibilisi-Ceyhan

  6. High Pressure Treatment in Foods


    Edwin Fabian Torres Bello; Gerardo González Martínez; Bernadette F. Klotz Ceberio; Dolores Rodrigo; Antonio Martínez López


    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 f...

  7. High Pressure Treatment in Foods


    Torres Bello, Edwin Fabian; González Martínez, Gerardo; Bernadette F. Klotz Ceberio; Rodrigo Aliaga, Mª Dolores; Martínez López, Antonio


    Abstract: 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...

  8. Crumpling under an ambient pressure


    Lin, Y C; Wang, Y. L.; Liu, Y; Hong, T.M.


    A pressure chamber is designed to study the crumpling process under an ambient force. The compression force and its resulting radius for the ball obey a power law with an exponent that is independent of the thickness and initial size of the sheet. However, the exponent is found to be material-dependent and less than the universal value, 0.25, claimed by the previous simulations. The power law behavior disappears at high pressure when the compressibility drops discontinuously, which is suggest...

  9. Cavitation pressure in liquid helium


    Caupin, Frederic; Balibar, Sebastien


    Recent experiments have suggested that, at low enough temperature, the homogeneous nucleation of bubbles occurs in liquid helium near the calculated spinodal limit. This was done in pure superfluid helium 4 and in pure normal liquid helium 3. However, in such experiments, where the negative pressure is produced by focusing an acoustic wave in the bulk liquid, the local amplitude of the instantaneous pressure or density is not directly measurable. In this article, we present a series of measur...

  10. Arterial Pressure Monitoring in Mice


    Zhao, Xin; Ho, David; Gao, Shumin; Hong, Chull; Vatner, Dorothy E.; Vatner, Stephen F.


    The use of mice for the evaluation and study of cardiovascular pathophysiology is growing rapidly, primarily due to the relative ease for developing genetically engineered mouse models. Arterial pressure monitoring is central to the evaluation of the phenotypic changes associated with cardiovascular pathology and interventions in these transgenic and knockout models. There are four major techniques for measuring arterial pressure in the mouse: tail cuff system, implanted fluid filled catheter...

  11. Optimization of compound pressure cylinders


    G.H. Majzoobi; A. Ghomi


    Purpose: The purpose of this paper is optimization of the weight of compound cylinder for a specific pressure. The variables are shrinkage radius and shrinkage tolerance.Design/methodology/approach: SEQ technique for optimization, the finite element code, ANSYS for numerical simulation are employed to predict the optimized conditions. The results are verified by testing a number of closed end cylinders with various geometries, materials and internal pressures.Findings: The weight of a compoun...

  12. Reference Handbook: Pressure relief devices

    International Nuclear Information System (INIS)

    The purpose of this handbook is to provide Rocky Flats personnel with the information necessary to understand and properly operate pressure relief devices. Upon completion of this handbook you should be able to do the following: Understand the different applications for pressure relief devices. Understand basic properties of gasses and liquids. Understand terminology associated with pressure relief devices. Understand the types, basic construction, and operation of pressure relief devices. Understand pressure relief device operating and troubleshooting practices. This handbook is designed for use by experienced Rocky Flats operators to reinforce and improve their current knowledge level, and by entry-level operators to ensure that they possess a minimum level of fundamental knowledge. Pressure Relief Devices is applicable to many job classifications and can be used as a reference for classroom work or for self-study. Although this reference handbook is by no means all-encompassing, you will gain enough information about this subject area to assist you in contributing to the safe operation of Rocky Flats Plant

  13. Pressure Tube and Pressure Vessel Reactors; certain comparisons

    International Nuclear Information System (INIS)

    In a comparison between pressure tube and pressure vessel type reactors for pressurized D2O coolant and natural uranium, one can say that reactors of these two types having the same net electrical output, overall thermal efficiency, reflected core volume and fuel lattice have roughly the same capital cost. In these circumstances, the fuel burn-up obtainable has a significant influence on the relative economics. Comparisons of burn-up values made on this basis are presented in this report and the influence on the results of certain design assumptions are discussed. One of the comparisons included is based on the dimensions and ratings proposed for CANDU. Moderator temperature coefficients are compared and differences in kinetic behaviour which generally result in different design philosophies for the two types are mentioned, A comparison of different methods of obtaining flux flattening is presented. The influence of slight enrichment and other coolants, (boiling D2O and gases) on the comparison between pressure tube and pressure vessel designs is discussed and illustrated with comparative designs for 400 MW electrical output. This paper was presented at the EAES Enlarged Symposium on Heterogeneous Heavy Water Power Reactors, Mallorca, October 10 - 14, 1960

  14. Automatic blood pressure measuring system (M092) (United States)

    Nolte, R. W.


    The Blood Pressure Measuring System is described. It measures blood pressure by the noninvasive Korotkoff sound technique on a continual basis as physical stress is imposed during experiment M092, Lower Body Negative Pressure, and experiment M171, Metabolic Activity.

  15. How Is High Blood Pressure Treated? (United States)

    ... from the NHLBI on Twitter. How Is High Blood Pressure Treated? Based on your diagnosis, health care providers ... the medicine suspected of causing your high blood pressure. If high blood pressure persists or is first diagnosed as primary ...

  16. Avoid the Consequences of High Blood Pressure (United States)

    ... Resources Stroke More Avoid the Consequences of High Blood Pressure Infographic Updated:Jun 19,2014 View a downloadable version of this infographic High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  17. Questions and Answers about High Blood Pressure (United States)

    ... Research Training & Career Development Grant programs for students, postdocs, and faculty Research at NIDDK Labs, faculty, and ... you have high blood pressure. How can I control or prevent high blood pressure? High blood pressure ...

  18. Automatic calibration system for pressure transducers (United States)


    Fifty-channel automatic pressure transducer calibration system increases quantity and accuracy for test evaluation calibration. The pressure transducers are installed in an environmental tests chamber and manifolded to connect them to a pressure balance which is uniform.

  19. 49 CFR 192.623 - Maximum and minimum allowable operating pressure; Low-pressure distribution systems. (United States)


    ... distribution systems. (a) No person may operate a low-pressure distribution system at a pressure high enough to...) No person may operate a low pressure distribution system at a pressure lower than the...

  20. Conformable pressure vessel for high pressure gas storage

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Kevin L.; Johnson, Kenneth I.; Lavender, Curt A.; Newhouse, Norman L.; Yeggy, Brian C.


    A non-cylindrical pressure vessel storage tank is disclosed. The storage tank includes an internal structure. The internal structure is coupled to at least one wall of the storage tank. The internal structure shapes and internally supports the storage tank. The pressure vessel storage tank has a conformability of about 0.8 to about 1.0. The internal structure can be, but is not limited to, a Schwarz-P structure, an egg-crate shaped structure, or carbon fiber ligament structure.

  1. Reactor vessel pressure transient protection for pressurized water reactors

    International Nuclear Information System (INIS)

    During the past few years the NRC has been studying the issue of protection of the reactor pressure vessels at Pressurized Water Reactors (PWRs) from transients when the vessels are at a relatively low temperature. This effort was prompted by concerns related to the safety margins available to vessel damage as a result of such events. Nuclear Reactor Regulation Category A Technical Activity No. A-26 was established to set forth the NRC plan for resolution of the generic aspects of this safety issue. The purpose of the report is to document the completion of this generic technical activity

  2. Pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    The primary objective of the ORNL pressurized-thermal-shock (PTS) experiments is to verify analytical methods that are used to predict the behavior of pressurized-water-reactor vessels under these accident conditions involving combined pressure and thermal loading. The criteria on which the experiments are based are: scale large enough to attain effective flaw border triaxial restraint and a temperature range sufficiently broad to produce a progression from frangible to ductile behavior through the wall at a given time; use of materials that can be completely characterized for analysis; stress states comparable to the actual vessel in zones of potential flaw extension; range of behavior to include cleavage initiation and arrest, cleavage initiation and arrest on the upper shelf, arrest in a high K/sub I/ gradient, warm prestressing, and entirely ductile behavior; long and short flaws with and without stainless steel cladding; and control of loads to prevent vessel burst, except as desired. A PTS test facility is under construction which will enable the establishment and control of wall temperature, cooling rate, and pressure on an intermediate test vessel (ITV) in order to simulate stress states representative of an actual reactor pressure vessel

  3. Pressure Measurement during Penetration Experiments (United States)

    Krause, C.; Demming, J.; Flecht, T.; Heller, S.


    Penetration experiments are common tools for the investigation of physical surface properties. Additionally penetration experiments will find several applications in exploration missions in the near future. A penetration test stand has been flown for the investigation of penetration force reduction under reduced gravity in the 2nd Joint European Partial-G Parabolic Flight Campaign (JEPPF-2) of ESA, CNES and DLR [1]. The main contribution to the bearing resistance of a soil is combined of shaft and base resistance. During the penetration the grains of the granular material will be squeezed into the surrounding material. The penetration will cause a change in the pressure distribution inside the surrounding soil [2],[3]. An experimental setup has been designed and built for understanding and measurement of this induced pressure distribution. In the last year the parabolic flight test stand has been further developed for the measurement of pressure during the penetration process. The main part of the experiments stayed the same with a steel rod penetration into a sample cell measuring the penetration force and recording it in relation to the depth. The sample cell is equipped with a supporting sieving mechanism for sample preparation. The pressure sensors are mounted at the sample cell. During the last test campaigns the principle of measurement has been investigated and first measurements have been performed. In the presentation the measurement principle will be shown and its implementation into the parabolic flight setup. Pressure measurement results on ground tests of different penetrator and tip configurations will be presented.

  4. Measuring Intracranial Pressure And Volume Noninvasively (United States)

    Cantrell, John H.; Yost, William T.


    Ultrasonic technique eliminates need to drill into brain cavity. Intracranial dynamics instrument probes cranium ultrasonically to obtain data for determination of intracranial pressure (ICP) and pressure-volume index (PVI). Instrument determines sensitivity of skull to changes in pressure and by use of mechanical device to exert external calibrated pressure on skull. By monitoring volume of blood flowing into jugular vein, one determines change of volume of blood in cranial system. By measuring response of skull to increasing pressure (where pressure increased by tilting patient known amount) and by using cranial blood pressure, one determines intial pressure in cerebrospinal fluid. Once PVI determined, ICP determined.

  5. Melting of Ice under Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Schwegler, E; Sharma, M; Gygi, F; Galli, G


    The melting of ice under pressure is investigated with a series of first principles molecular dynamics simulations. In particular, a two-phase approach is used to determine the melting temperature of the ice-VII phase in the range of 10 to 50 GPa. Our computed melting temperatures are consistent with existing diamond anvil cell experiments. We find that for pressures between 10 to 40 GPa, ice melts as a molecular solid. For pressures above {approx}45 GPa there is a sharp increase in the slope of the melting curve due to the presence of molecular dissociation and proton diffusion in the solid, prior to melting. The onset of significant proton diffusion in ice-VII as a function of increasing temperature is found to be gradual and bears many similarities to that of a type-II superionic solid.

  6. Interarm difference in blood pressure

    DEFF Research Database (Denmark)

    Mehlsen, Jesper; Wiinberg, Niels


    The present study aimed at examining the interarm difference in blood pressure and its use as an indicator of peripheral arterial disease (PAD). Data were included from consecutive patients referred from their general practitioner to our vascular laboratory for possible PAD aged 50 years or older...... without known cardiac disease, renal disease, or diabetes mellitus. 824 patients (453 women) with mean age of 72 years (range: 50-101) were included. 491 patients had a diagnosis of hypertension and peripheral arterial disease (PAD) was present in 386 patients. Systolic blood pressure was 143 ± 24 mm......Hg and 142 ± 24 mmHg on the right and left arm, respectively (P = 0.015). The interarm difference was greater in patients with hypertension (P = 0.002) and PAD (P < 0.0005). 443 patients were measured on two separate occasions and the interarm difference for systolic blood pressure was reproducible for...

  7. Domestic atmospheric pressure thermal deaerators (United States)

    Egorov, P. V.; Gimmelberg, A. S.; Mikhailov, V. G.; Baeva, A. N.; Chuprakov, M. V.; Grigoriev, G. V.


    Based on many years of experience and proven technical solutions, modern atmospheric pressure deaerators of the capacity of 0.4 to 800 t/h were designed and developed. The construction of such deaerators is based on known and explored technical solutions. A two-stage deaeration scheme is applied where the first stage is a jet dripping level (in a column) and the second one is a bubble level (in a tank). In the design of deaeration columns, low-pressure hydraulic nozzles (Δ p TPP at heating and industrial-heating plants. The atmospheric pressure thermal deaerators developed at NPO TsKTI with consideration of the current requirements are recommended for the use in water preparation schemes of various power facilities.

  8. The German pressure vessel code

    International Nuclear Information System (INIS)

    The philosophy and the safety aspects of the German pressure vessel code is summarised. Emphasis is laid upon material selection, design, manufacture and inspection. The AD specifications, which are embedded in the German regulation for the prevention of accidents 'Pressure Vessels' are compiled primarily to give a measure of safety to the average plant. The possible types of failure are discussed in connection with design aspects. It is shown in detail how the AD specifications count for inelastic material behaviour. A comparison is also made between the German code and the ASME boiler and pressure vessel code. Comparatively, the allowable stresses due to the German code are higher, leading to thinner walls in many cases. This is compensated for by rigorous inspection and non-destructive testing during manufacture. Regular examinations round up the system of safety. It is concluded that the German code gives a high degree of safety and flexibility to the manufacturer. (author)

  9. Dissociation pressure of polonium dioxide

    International Nuclear Information System (INIS)

    Information on determining the temperature dependence of the vapour pressure during polonium-210 dissociation is given. To determine the vapour pressure of polonium during PoO2 dissociation, the method based on remote measuring the amount of the vapour of the radioactive element by its own radiation in a known volume with dynamic equilibrium inside an ampoule evacuated to 10-2 Torr has been used. The vapour pressure of P0 in vacuum within the temperature range from 530 to 595 deg C obeys the equation lg Psub(mm)=19.4440+-0.7140-(16920+-50O)/T. The polonium evaporation heat during PoO2 dissociation is 77.4+-2.3 kcal/mol. Enthalpy of PoO2 dissociation is 154.8 kcal/mol

  10. IIH with normal CSF pressures?

    Directory of Open Access Journals (Sweden)

    Soh Youn Suh


    Full Text Available Idiopathic intracranial hypertension (IIH is a condition of raised intracranial pressure (ICP in the absence of space occupying lesions. ICP is usually measured by lumbar puncture and a cerebrospinal fluid (CSF pressure above 250 mm H 2 O is one of the diagnostic criteria of IIH. Recently, we have encountered two patients who complained of headaches and exhibited disc swelling without an increased ICP. We prescribed acetazolamide and followed both patients frequently; because of the definite disc swelling with IIH related symptoms. Symptoms and signs resolved in both patients after they started taking acetazolamide. It is generally known that an elevated ICP, as measured by lumbar puncture, is the most important diagnostic sign of IIH. However, these cases caution even when CSF pressure is within the normal range, that suspicion should be raised when a patient has papilledema with related symptoms, since untreated papilledema may cause progressive and irreversible visual loss.

  11. Internal pressure and solubility parameter as a function of pressure

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Andersen, Simon Ivar


    maximum contrary to solubility parameter. An indirect method was chosen to estimate internal pressure, using thermal expansivities (determined by microcalorimetry) and isothermal compressibilities (determined by density measurements). The uncertainty is within 2% for the expansivity and 0.1% for the...

  12. High Pressure Treatment in Foods

    Directory of Open Access Journals (Sweden)

    Edwin Fabian Torres Bello


    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.

  13. Microplasma jet at atmospheric pressure

    International Nuclear Information System (INIS)

    A nitrogen microplasma jet operated at atmospheric pressure was developed for treating thermally sensitive materials. For example, the plasma sources in treatment of vulnerable biological materials must operate near the room temperature at the atmospheric pressure, without any risk of arcing or electrical shock. The microplasma jet device operated by an electrical power less than 10 W exhibited a long plasma jet of about 6.5 cm with temperature near 300 K, not causing any harm to human skin. Optical emission measured at the wide range of 280-800 nm indicated various reactive species produced by the plasma jet

  14. Partial pressure analysis of plasmas

    International Nuclear Information System (INIS)

    The application of partial pressure analysis for plasma diagnostic measurements is reviewed. A comparison is made between the techniques of plasma flux analysis and partial pressure analysis for mass spectrometry of plasmas. Emphasis is given to the application of quadrupole mass spectrometers (QMS). The interface problems associated with the coupling of a QMS to a plasma device are discussed including: differential-pumping requirements, electromagnetic interferences from the plasma environment, the detection of surface-active species, ion source interactions, and calibration procedures. Example measurements are presented from process monitoring of glow discharge plasmas which are useful for cleaning and conditioning vacuum vessels

  15. 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......–PAGE gels of myofibrillar protein extract from HP treated meat showed that myofibrillar proteins form high molecular weight aggregates after HP treatment. Myofibrillar protein aggregates were stable in a reducing environment, suggesting that disulfide bonds are not the main molecular interactions...

  16. WWER reactor pressure vessel design

    International Nuclear Information System (INIS)

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. The details of WWER reactor pressure vessel design, as used in the PWR type reactors of the former USSR are given in chapter 4. General design concepts are given as well as specific material requirements. Safety concepts and lifetime assurance are discussed briefly

  17. Blood pressure modifies retinal susceptibility to intraocular pressure elevation.

    Directory of Open Access Journals (Sweden)

    Zheng He

    Full Text Available Primary open angle glaucoma affects more than 67 million people. Elevated intraocular pressure (IOP is a risk factor for glaucoma and may reduce nutrient availability by decreasing ocular perfusion pressure (OPP. An interaction between arterial blood pressure and IOP determines OPP; but the exact contribution that these factors have for retinal function is not fully understood. Here we sought to determine how acute modifications of arterial pressure will affect the susceptibility of neuronal function and blood flow to IOP challenge. Anaesthetized (ketamine:xylazine Long-Evan rats with low (∼60 mmHg, sodium nitroprusside infusion, moderate (∼100 mmHg, saline, or high levels (∼160 mmHg, angiotensin II of mean arterial pressure (MAP, n = 5-10 per group were subjected to IOP challenge (10-120 mmHg, 5 mmHg steps every 3 minutes. Electroretinograms were measured at each IOP step to assess bipolar cell (b-wave and inner retinal function (scotopic threshold response or STR. Ocular blood flow was measured using laser-Doppler flowmetry in groups with similar MAP level and the same IOP challenge protocol. Both b-wave and STR amplitudes decreased with IOP elevation. Retinal function was less susceptible to IOP challenge when MAP was high, whereas the converse was true for low MAP. Consistent with the effects on retinal function, higher IOP was needed to attenuated ocular blood flow in animals with higher MAP. The susceptibility of retinal function to IOP challenge can be ameliorated by acute high BP, and exacerbated by low BP. This is partially mediated by modifications in ocular blood flow.

  18. Vital Signs - High Blood Pressure

    Centers for Disease Control (CDC) Podcasts


    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.

  19. Vapour Pressure of Diethyl Phthalate

    Czech Academy of Sciences Publication Activity Database

    Roháč, V.; Růžička, K.; Růžička, V.; Zaitsau, D. H.; Kabo, G. J.; Diky, V.; Aim, Karel


    Roč. 36, č. 11 (2004), s. 929-937. ISSN 0021-9614 Institutional research plan: CEZ:AV0Z4072921 Keywords : vapour pressure * diethyl phthalate * correlation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.144, year: 2004

  20. Pressure transducers for cryogenic liquids

    Directory of Open Access Journals (Sweden)

    Pavlovskyy I. V.


    Full Text Available The developed universal construction of tensoresistive pressure transducer for cryogenic liquids (liquid nitrogen and liquid helium is described. The study of strain gauges characteristics on the basis of p-type Si whiskers with different boron concentration, mounted on the invar spring elements (beams, in the wide ranges of strain ε=±1,2·10-3 and temperature 4,2-300 К for transducers simulation were carried out. It was shown that using heavily doped silicon strain gages gives the possibility to develop pressure transducers for liquid nitrogen and liquid helium based on the classic piezoresistance. The significant increasing of the pressure transducers sensitivity for liquid helium could be achieved by using the strain gages on the basis of silicon with boron concentration in the vicinity of metal-insulator transition based on the non-classic piezoresitance. Developed pressure transducers for cryogenic liquids with strain gauges on the basis of doped p-type Si whiskers are presented.

  1. Pressure gauge experiments in India

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desa, E.; VijayKumar, K.; Desa, E.S.; Desai, R.G.P.; Prabhudesai, S.

    Pressure measurements made in differing turbid water bodies and turbulent clear-water bodies have led to the inference that the effective mean-depth in situ density value, Row eff, of these water bodies is less than the corresponding bulk density...

  2. Critical conditions of pressurized pipes

    Czech Academy of Sciences Publication Activity Database

    Gajdoš, Lubomír; Šperl, Martin


    Roč. 20, č. 5 (2013), s. 401-412. ISSN 1802-1484 R&D Projects: GA ČR(CZ) GAP105/10/2052 Institutional support: RVO:68378297 Keywords : pressurized pipe * J-integral * C factor * critical conditions Subject RIV: JL - Materials Fatigue, Friction Mechanics

  3. Preconsolidation Pressure and Creep Settlements

    DEFF Research Database (Denmark)

    Thorsen, Grete

    oedometer tests with undisturbed samples have been analysed by means of different methods to determine the pre-consolidation pressure. An attempt is made to estimate the creep rates on the basis of AMS 14C-datings of the sediments and a model for creep determination proposed by Moust Jacobsen....

  4. Recent high pressure photoluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Drickamer, H.G.; Lang, J.M.; Dreger, Z.A. (Department of Chemical Engineering, University of Illinois, 1209 W. California Street, Urbana, Illinois 61801 (United States))


    In this paper we discuss two studies involving the effect of pressure on luminescence properties of organic molecules in polymeric media. (1) The efficiency of energy transfer from Coumarine 138 to Rhodamine B in polyacrylic acid (PAA) is measured by both steady state and time dependent methods. The Forster efficiency'' obtained by these two methods is consistent and shows the same pressure dependence as efficiencies derived from relative peak intensities. The non-monotonic pressure dependence of the efficiency is accounted for in terms of the properties of the molecules and the media. (2) The effect of pressure on the luminescent efficiency of molecules with two or more possible excited state geometries has been measured. The efficiency is described in terms of the non-radiative dissipation of energy from a planar excited state and the rates of crossing to and from the possible twisted states as well as non-radiative decay from these states. The processes involved in these two studies are pertinent to a number of technologically and biologically important processes. [copyright]American Institute of Physics

  5. Recent high pressure photoluminescence studies

    International Nuclear Information System (INIS)

    In this paper we discuss two studies involving the effect of pressure on luminescence properties of organic molecules in polymeric media. (1) The efficiency of energy transfer from Coumarine 138 to Rhodamine B in polyacrylic acid (PAA) is measured by both steady state and time dependent methods. The ''Forster efficiency'' obtained by these two methods is consistent and shows the same pressure dependence as efficiencies derived from relative peak intensities. The non-monotonic pressure dependence of the efficiency is accounted for in terms of the properties of the molecules and the media. (2) The effect of pressure on the luminescent efficiency of molecules with two or more possible excited state geometries has been measured. The efficiency is described in terms of the non-radiative dissipation of energy from a planar excited state and the rates of crossing to and from the possible twisted states as well as non-radiative decay from these states. The processes involved in these two studies are pertinent to a number of technologically and biologically important processes. copyright American Institute of Physics

  6. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics Atherosclerosis DASH Eating Plan Overweight and Obesity Smoking and Your Heart Stroke Send a link ...

  7. Water Pressure. Water in Africa. (United States)

    Garrett, Carly Sporer

    The Water in Africa Project was realized over a 2-year period by a team of Peace Corps volunteers. As part of an expanded, detailed design, resources were collected from over 90 volunteers serving in African countries, photos and stories were prepared, and standards-based learning units were created for K-12 students. This unit, "Water Pressure,"…

  8. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Technology Transfer Clinical Trials What Are Clinical Trials? Children & Clinical Studies NHLBI Trials Clinical Trial Websites News & ... are consistently higher than 120/80 mmHg. Your child’s blood pressure numbers are outside average numbers for ...

  9. High Blood Pressure in Pregnancy (United States)

    ... Talk to your doctor about any over-the-counter medications you are taking or are thinking about taking. Does Hypertension or Preeclampsia During Pregnancy Cause Long-Term Heart and Blood Vessel Problems? The effects of high blood pressure during pregnancy vary depending on the disorder and ...

  10. Graphene based piezoresistive pressure sensor

    NARCIS (Netherlands)

    Zhu, S.E.; Ghatkesar, M.K.; Zhang, C.; Janssen, G.C.A.M.


    We present a pressure sensor based on the piezoresistive effect of graphene. The sensor is a 100 nm thick, 280 μm wide square silicon nitride membrane with graphene meander patterns located on the maximum strain area. The multilayer, polycrystalline graphene was obtained by chemical vapor deposition

  11. The Vapour Pressure of Plutonium

    International Nuclear Information System (INIS)

    The vapour pressure of liquid plutonium has been determined over the temperature range 1100 to 1800°K by the Knudsen effusion method. The least-squares equation which fits the data is log10p(atm) = -17 420/T(°K) + 4.913. The standard deviation corresponds to about ±10% in the pressures calculated from this equation. The heat of vaporization computed from the temperature dependence of the experimental data is ΔH0298 = 82.3 kcal/g-at. The heat computed by combining independent entropy and heat capacity data with the present measurements is ΔH0298 = 82.1 kcal/g-at. Effects of oxygen upon the volatility of liquid plutonium were sought by comparing the vapour pressures observed with the liquid in contact with tantalum, tantalum carbide, magnesia, and plutonium sesquioxide. No differences were found. In addition, the vapour pressure was measured with different degrees of vacuum in the system. No effect was found here either, except that in very poor vacuums a surface film of oxide apparently formed and reduced the volatility by about a factor of 2. (author)

  12. 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 ...

  13. The Power of Peer Pressure (United States)

    Wingle, Jane


    In a religion class of 26 bright creative sixth graders, one student demonstrates the power of peer pressure. Part of the morning ritual is to say prayer petitions. Students seems to be calmed by their expressions of care for their families, friends, pets, their military troops, victims of natural disasters, the homeless, etc. However, one student…

  14. History of Physical Terms: "Pressure" (United States)

    Frontali, Clara


    Scientific terms drawn from common language are often charged with suggestions that may even be inconsistent with their restricted scientific meaning, thus posing didactic problems. The (non-linear) historical journey of the word "pressure" is illustrated here through original quotations from Stevinus, Torricelli, Pascal, Boyle,…

  15. Malthusian pressures, genocide, and ecocide. (United States)

    Richter, Elihu D; Blum, Rony; Berman, Tamar; Stanton, Gregory H


    Historical models postulate that genocide cannot occur without the ideology and decisions of its authoritarian perpetrators and the indifference of bystanders. These models do not address genocidal risks from ecocide. Study objectives were to assess 1) the role of Malthusian pressures in recent genocides, 2) the role of ecocide and ecologic abuse in creating these pressures, and 3) strategies for prevention and deterrence. Analysis of reports, demographic studies, and time trends in recent genocides and recent ecocidal events from ecologic abuse suggests that Malthusian pressures and zero-sum rivalries over water, arable land, or natural resources by themselves do not lead to genocide. Such pressures may have exacerbated the political and socioeconomic predictors in Rwanda and Darfur, but not in former Yugoslavia. However, collapse of socioeconomic and governmental infrastructures following genocide can leave behind massive sustained damage to carrying capacity and sustainability. Surviving victims, if they return to their environments, will remain at risk for persecution. Ecocide--the large-scale destruction, depletion, or contamination of natural ecosystems--can result in widespread damage to health, survival, fertility, reproduction, and sustenance, and forced flight. International early warning and effective response systems are needed to deter or prevent political decisions to carry out genocide. Such systems must include long-term measures to resolve zero-sum conflicts over environmental resources and to prevent toxic risks to vulnerable populations and destruction of habitat by deliberate or wanton ecologic abuse, which itself should be redefined as a crime against humanity. PMID:17915548

  16. Zero-pressure organic superconductor

    DEFF Research Database (Denmark)

    Bechgaard, K.; Carneiro, K.; Olsen, M.; Jacobsen, C.S.; Rasmussen, Finn Berg


    Evidence for superconductivity in the organic conductor di-(tetramethyltetraselenafulvalenium)-perchlorate [(TMTSF)2ClO4] has been found by resistance measurements in the absence of applied pressure. For different crystals the transitions are approximately 0.3 K wide and are centered around...

  17. Diagnosis of High Blood Pressure

    Medline Plus

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

  18. Three Beam Interfering Pressure Gauge①

    Institute of Scientific and Technical Information of China (English)

    WUZhaoxia; TANGXuhui; 等


    In order to solve the problem of high precision,complete electric insulating detection of the pressure measuring system,we have developed the three-beam interferometer.In this paper,the operation principle,structure of the system and measuring results are given.

  19. Primary pump suction pressure limits

    International Nuclear Information System (INIS)

    In conjunction with the operational testing program which was carried out prior to the startup of N Reactor, a study was carried out to establish limits for suction pressure of the primary (reactor coolant) pumps. The purpose of the report is to document the results of the study and interpret them with respect to the current mode of reactor operation

  20. Diagnosis of High Blood Pressure

    Medline Plus

    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 ...

  1. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.;


    as well as with the filling of the cavity by the polymer melt. In this paper, two parameters derived from cavity pressure over time (i.e. pressure work). The influence of four µIM parameters (melt temperature, mould temperature, injection speed, aand packing pressure) on the two pressure...

  2. Determination of Secondary Encasement Pipe Design Pressure

    International Nuclear Information System (INIS)

    This document published results of iterative calculations for maximum tank farm transfer secondary pipe (encasement) pressure upon failure of the primary pipe. The maximum pressure was calculated from a primary pipe guillotine break. Results show encasement pipeline design or testing pressures can be significantly lower than primary pipe pressure criteria

  3. Blood Pressure Patterns May Predict Stroke Risk (United States)

    ... pressure from normal systolic blood pressure (120 mm Hg) in middle age to high (160 mm Hg). Normal blood pressure in middle age but a steep rise to very high (200 mm Hg). Moderately high blood pressure (140 mm Hg) in ...

  4. Transient dynamics of drilling riser during disconnect


    Bratseth, Svein


    Drilling of petroleum wells have traditionally be done by adjusting the mud weight to balance pressure of the well. A new method of controlling well pressure is called controlled mud cap drilling. The method uses high mud weight and constantly changing the mud height to adjust the bottom hole pressure. This allows for drilling wells which previously were considered un-drillable.Drilling of wells might be done by a floating drilling vessel, which might drift off. In such cases an emergency dis...

  5. Pressure analysis for horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Spivak, D.


    This study deals with the solution for pressure response of horizontal wells in three different anisotropic media: the infinite reservoir, the limited reservoir and the reservoir with constant pressure at the outer boundaries. Pressure analyses for vertical wells in various reservoirs are abundant, but there has been no comprehensive study of pressure analysis for horizontal wells in these three media. The objectives of this work are to examine and to determine the likely effects of horizontal wells on productivity and on the integration of pressure tests. The method of images, the concept of instantaneous sources and the Newman product method have been used. Integration of the summed source functions is achieved numerically using Simpson's rule. All three solutions are semi-analytical and have been verified and validated. For the infinite reservoir the solution has been compared to a directional well of high angle, and long horizontal well responses have been compared to the solution for the uniform-flux vertical fracture. The solutions to the other two cases (for long horizontal wells) have been compared to published solutions for uniform-flux vertical fractures. New equations, new pseudo-skin factors, new type curves, and new shape factors have been generated in the course of this work. The log-log type curves can be used to determine reservoir characteristics. The influences of different well and reservoir parameters on the well productivity have been investigated and are presented to show the merits of horizontal wells. A major features of this study is that some portions are presented here for the first time.

  6. Nonequilibrium thermodynamics of pressure solution (United States)

    Lehner, F. K.; Bataille, J.


    This paper is concerned with the thermodynamic theory of solution and precipitation processes in wet crustal rocks and with the mechanism of steady pressure-solution slip in ‘contact zones,’ such as grain-to-grain contacts, fracture surfaces, and permeable gouge layers, that are infiltrated by a mobile aqueous solution phase. A local dissipation jump condition at the phase boundary is fundamental to identifying the thermodynamic force driving the solution and precipitation process and is used here in setting up linear phenomenological relations to model near-equilibrium phase transformation kinetics. The local thermodynamic equilibrium of a stressed pure solid in contact with its melt or solution phase is governed by Gibbs's relation, which is rederived here, in a manner emphasizing its independence of constitutive assumptions for the solid while neglecting surface tension and diffusion in the solid. Fluid-infiltrated contact zones, such as those formed by rough surfaces, cannot generally be in thermodynamic equilibrium, especially during an ongoing process of pressure-solution slip, and the existing equilibrium formulations are incorrect in overlooking dissipative processes tending to eliminate fluctuations in superficial free energies due to stress concentrations near asperities, defects, or impurities. Steady pressure-solution slip is likely to exhibit a nonlinear dependence of slip rate on shear stress and effective normal stress, due to a dependence of the contact-zone state on the latter. Given that this dependence is negligible within some range, linear relations for pressure-solution slip can be derived for the limiting cases of diffusion-controlled and interface-reaction-controlled rates. A criterion for rate control by one of these mechanisms is set by the magnitude of the dimensionless quantity kδ/2C pD, where k is the interfacial transfer coefficient, δ is the mean diffusion path length, C p is the solubility at pressure p, and D is the mass

  7. Miniature, Cooled Pressure-Measuring Probe (United States)

    Ashby, George C., Jr.; Eves, John W.; White, David R.


    Probe designed to reduce settling time dramatically. Pressure-sensing transducer mounted in probe and connected to tip by short tube having cross-sectional area substantially smaller than conventional connecting tubes. Probe includes stainless-steel cylindrical exterior housing holding closed pressure chamber in which piezoelectric pressure transducer mounted. Open connecting tube passes portion of high-velocity, high-temperature fluid stream into closed pressure chamber. Any change of pressure in sampled stream propagates into closed pressure chamber with settling time inversely proportional to cross-sectional area of connecting tube. Cooling chamber formed around pressure chamber connected to source of water or other cooling fluid via inlet and outlet tubes.

  8. Introduction of Korean pressure vessel code

    International Nuclear Information System (INIS)

    As of the present date, pressure related components installed in Korea's Nuclear and Thermal Power Plants have been designed, manufactured, and operated in accordance with various foreign Pressure Vessel Codes. Because of the difficulties applying differing Codes, the Korean Engineering Societies have been putting forth the efforts in the development of the Korean Pressure Vessel Code since early 1992. This paper introduces the Korean Pressure Vessel Code, relating to pressure retaining components, and discusses the contents of that Code

  9. Effect of overbalance pressure on formation damage

    Energy Technology Data Exchange (ETDEWEB)

    Jilani, S.Z.; Menouar, H.; Al-Majed, A.A. [Center for Petroleum and Minerals, The Research Institute, King Fahd University of Petroleum and Minerals, Mail Box 2002, 31261 Dhahran (Saudi Arabia); Khan, M.A. [Center for Applied Physical Sciences, The Research Institute, King Fahd University of Petroleum and Minerals, 31261 Dhahran (Saudi Arabia)


    Experiments were conducted to investigate the influence of overbalance pressure on formation damage during drilling operations. An innovative ultrasonic method was employed to measure mud invasion depth. It was observed that mud invasion depth decreases with increasing overbalance pressure until it reaches a critical pressure. Beyond that, invasion depth increases with overbalance pressure. The above phenomenon reflects a strong physical relationship between overbalance pressure and mud fines and filtrate invasion depth.

  10. Research on Normal Human Plantar Pressure Test

    Directory of Open Access Journals (Sweden)

    Liu Xi Yang


    Full Text Available FSR400 pressure sensor, nRF905 wireless transceiver and MSP40 SCM are used to design the insole pressure collection system, LabVIEW is used to make HMI of data acquisition, collecting a certain amount of normal human foot pressure data, statistical analysis of pressure distribution relations about five stages of swing phase during walking, using the grid closeness degree to identify plantar pressure distribution pattern recognition, and the algorithm simulation, experimental results demonstrated this method feasible.

  11. Orion Suit Loop Variable Pressure Regulator Development (United States)

    Mosher, Michael; Vassallo, Andrew; Lewis, John F.; Campbell, Melissa


    The Orion Multi Purpose Crew Vehicle (MPCV) integrates the cabin and pressure suits with the core life support systems to provide life support during contingency depressurized cabin operations. To provide the multipule suit pressures between nominal pressurized cabin suited operations, suit leak checks, depressurized cabin suited operations, and elevated suit pressure for denitrification, a variable pressure regulator is needed. This paper documents the development and integrated testing of the suit loop regulator for Orion.

  12. Pressurized Thermal Shock Analysis for OPR1000 Pressure Vessel

    International Nuclear Information System (INIS)

    The study provides a brief understanding of the analysis procedure and techniques using ANSYS, such as the acceptance criteria, selection and categorization of events, thermal analysis, structural analysis including fracture mechanics assessment, crack propagation and evaluation of material properties. PTS may result from instrumentation and control malfunction, inadvertent steam dump, and postulated accidents such as smallbreak (SB) LOCA, large-break (LB) LOCA, main steam line break (MSLB), feedwater line breaks and steam generator overfill. In this study our main focus is to consider only the LB LOCA due to a cold leg break of the Optimized Power Reactor 1000 MWe (OPR1000). Consideration is given as well to the emergency core cooling system (ECCS) specific sequence with the operating parameters like pressure, temperature and time sequences. The static structural and thermal analysis to investigate the effects of PTS on RPV is the main motivation of this study. Specific surface crack effects and its propagation is also considered to measure the integrity of the RPV. This study describes the procedure for pressurized thermal shock analysis due to a loss of coolant accidental condition and emergency core cooling system operation for reactor pressure vessel.. Different accidental events that cause pressurized thermal shock to nuclear RPV that can also be analyzed in the same way. Considering the limitations of low speed computer only the static analysis is conducted. The modified LBLOCA phases and simplified geometry can is utilized to analyze the effect of PTS on RPV for general understanding not for specific specialized purpose. However, by integrating the disciplines of thermal and structural analysis, and fracture mechanics analysis a clearer understanding of the total aspect of the PTS problem has resulted. By adopting the CFD, thermal hydraulics, uncertainties and risk analysis for different type of accidental conditions, events and sequences with proper

  13. Cast support for a pressure vessel at high internal pressure

    International Nuclear Information System (INIS)

    The invention concerns a cast support for a pressure vessel, which is sealed with a liner. In order to prevent bulging of the liner which is not fixed to the cast support, a supporting intermediate layer is situated between the liner and the cast support. The cast support is only anchored in the supporting intermediate layer in certain areas. Several types of anchoring are described for the cast support. (orig.)

  14. High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors (United States)

    Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender


    Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

  15. Relating external compressing pressure to mean arterial pressure in non-invasive blood pressure measurements. (United States)

    Chin, K Y; Panerai, R B


    Arterial volume clamping uses external compression of an artery to provide continuous non-invasive measurement of arterial blood pressure. It has been assumed that mean arterial pressure (MAP) corresponds to the point where unloading leads to the maximum oscillation of the arterial wall as reflected by photoplethysmogram (PPG), an assumption that has been challenged. Five subjects were recruited for the study (three males, mean age (SD) = 32 (15) years). The PPG waveform was analysed to identify the relationship between the external compressing pressure, PPG pulse amplitude and MAP. Two separate tests were carried out at compression step intervals of 10 mmHg and 2 mmHg, respectively. No significant differences were found between the two tests. The bias between the compressing pressure and the MAP was -4.7 ± 5.63 mmHg (p < 0.001) showing a normal distribution. Further research is needed to identify optimal algorithms for estimation of MAP using PPG associated with arterial compression. PMID:25429784

  16. Pressure vessel and piping codes

    International Nuclear Information System (INIS)

    Section III of the ASME Boiler and Pressure Vessel Code contains simplified design formulas for placing bounds on the plastic deformations in nuclear power plant piping systems. For Class 1 piping a simple equation is given in terms of primary load stress indices (B1 and B2) and nominal pressure and bending stresses. The B1 and B2 stress indices reflect the capacities of various piping products to carry load without gross plastic deformation. In this paper, the significance of the indices, nominal stresses, and limits given in the Code for Class 1 piping and corresponding requirements for Class 2 and Class 3 piping are discussed. Motivation behind recent (1978-1981) changes in the indices and in the associated stress limits is presented

  17. Closed incision negative pressure therapy

    DEFF Research Database (Denmark)

    Willy, Christian; Agarwal, Animesh; Andersen, Charles A;


    Surgical site occurrences (SSOs) affect up to or over 25% of patients undergoing operative procedures, with the subset of surgical site infections (SSIs) being the most common. Commercially available closed incision negative pressure therapy (ciNPT) may offer surgeons an additional option to manage...... of Controlled Trials using key words 'prevention', 'negative pressure wound therapy (NPWT)', 'active incisional management', 'incisional vacuum therapy', 'incisional NPWT', 'incisional wound VAC', 'closed incisional NPWT', 'wound infection', and 'SSIs' identified peer-reviewed studies published from 2000....... A majority presented data supporting ciNPT use. Numerous publications reported SSI risk factors, with the most common including obesity (body mass index ≥30 kg/m(2) ); diabetes mellitus; tobacco use; or prolonged surgical time. We recommend that the surgeon assess the individual patient's risk factors...

  18. Pressurized-thermal-shock technology

    International Nuclear Information System (INIS)

    It was recognized at the time the original Issues on Pressurized Thermal Shock (IPTS) studies were conducted that distinct vertical plumes of cooling water form beneath the cold leg inlet nozzles during those particular transients that exhibit fluid/thermal stratification. The formation of these plumes (referred to as thermal streaming) induces a time-dependent circumferential temperature variation on the inner surface of the Reactor Pressure Vessel (RPV) wall that creates an axial stress component. This axial stress component is in addition to the axial stress components induced by time-dependent radial temperature variation through the wall thickness and the time-dependent pressure transient. This additional axial stress component will result in a larger axial stress resultant that results in a larger stress-intensity factor acting on circumferential flaws, thus reducing the fracture margin for circumferential flaws. Although this was recognized at the time of the original IPTS study, the contribution appeared to be relatively small; therefore, it was neglected. The original IPTS studies were performed with OCA-P, a computer program developed at ORNL to analyze the cleavage fracture response of a nuclear RPV subjected to PTS loading. OCA-P is a one-dimensional (1-D) finite-element code that analyzes the stresses and stress-intensity factors (axial and tangential) resulting from the pressure and the radial temperature variation through the wall thickness only. The HSST Program is investigating the potential effects of thermal-streaming-induced stresses in circumferential welds on the reactor vessel PTS analyses. The initial phase of this investigation focused on an evaluation of the available thermal-hydraulic data and analyses results. The objective for the initial phase of the investigation is to evaluate thermal-streaming behavior under conditions relevant to the operation of U.S. PWRs and chracterize any predicted thermal-streaming plumes

  19. Ultrasonic sludge pretreatment under pressure. (United States)

    Le, Ngoc Tuan; Julcour-Lebigue, Carine; Delmas, Henri


    The objective of this work was to optimize the ultrasound (US) pretreatment of sludge. Three types of sewage sludge were examined: mixed, secondary and secondary after partial methanisation ("digested" sludge). Thereby, several main process parameters were varied separately or simultaneously: stirrer speed, total solid content of sludge (TS), thermal operating conditions (adiabatic vs. isothermal), ultrasonic power input (PUS), specific energy input (ES), and for the first time external pressure. This parametric study was mainly performed for the mixed sludge. Five different TS concentrations of sludge (12-36 g/L) were tested for different values of ES (7000-75,000 kJ/kgTS) and 28 g/L was found as the optimum value according to the solubilized chemical oxygen demand in the liquid phase (SCOD). PUS of 75-150 W was investigated under controlled temperature and the "high power input - short duration" procedure was the most effective at a given ES. The temperature increase in adiabatic US application significantly improved SCOD compared to isothermal conditions. With PUS of 150 W, the effect of external pressure was investigated in the range of 1-16 bar under isothermal and adiabatic conditions for two types of sludge: an optimum pressure of about 2 bar was found regardless of temperature conditions and ES values. Under isothermal conditions, the resulting improvement of sludge disintegration efficacy as compared to atmospheric pressure was by 22-67% and 26-37% for mixed and secondary sludge, respectively. Besides, mean particle diameter (D[4,3]) of the three sludge types decreased respectively from 408, 117, and 110 μm to about 94-97, 37-42, and 36-40 μm regardless of sonication conditions, and the size reduction process was much faster than COD extraction. PMID:23587728

  20. Low pressure solar thermal converter


    Muller, Gerald


    The current development of solar power converters with air as working fluid focuses mostly on concentrating collectors combined with hot-air engines, and on very low temperature solar tower concepts. Whilst concentrating collectors and Stirling engines need complex technology, solar tower converters have very low efficiencies and require large installations. Pressurized containers as energy converters offer the advantage of simplicity, but appear not to have been investigated in detail. ...

  1. Pressure losses in pneumatic transport


    Ottjes, J.A.


    A model is derived to calculate the pressure losses originating from the dilute phase pneumatic transport of coarse particles in the horizontal stationary flow regime. The model is based on the balance of drag forces and frictional forces acting on the particles during pneumatic transport. The particles are characterized by the particle terminal velocity, the particle âwall sliding friction coefficient and the coefficient of restitution between particles and wall. The influence of the inhomog...

  2. Rejection index for pressure tubes

    International Nuclear Information System (INIS)

    The objective of the present study was to establish a set of criteria (or Rejection Index) which could be used to decide whether a zirconium-2 1/2 w/o niobium pressure tube in a CANDU reactor should be removed from service due to in-service degradation. A critique of key issues associated with establishing a realistic rejection index was prepared. Areas of uncertainty in available information were identified and recommendations for further analysis and laboratory testing made. A Rejection Index based on the following limits has been recommended: 1) Limits related to design intent and normal operation: any garter spring must remain within the tolerance band specified for its design location; the annulus gas system must normally be operated in a circulating mode with a procedure in place for purging to prevent accumulation of deuterium. It must remain sensitive to leaks into any part of the systems; and pressure tube dimensions and distortions must be limited to maintain the fuel channels within the original design intent; 2) Limits related to defect tolerance: adequate time margins between occurrence of a leaking crack and unstable failure must be demonstrated for all fuel channels; long lap-type flaws are unacceptable; crack-like defects of any size are unacceptable; and score marks, frat marks and other defects with contoured profiles must fall below certain depth, length and stress intensity limits; and 3) Limits related to property degradation: at operating temperature each pressure tube must be demonstrated to have a critical length in excess of a stipulated value; the maximum equivalent hydrogen level in any pressure tube should not exceed a limit which should be defined taking into account the known history of that tube; the maximum equivalent hydrogen level in any rolled joint should not exceed a limit which is presently recommended as 200 ppm equivalent hydrogen; and the maximum diametral creep strain should be limited to less than 5%

  3. TBM pressure models: calculation tools


    Gerheim Souza Dias, Tiago; Bezuijen, Adam


    Mechanized tunnel construction in soft ground has evolved significantly over the last 20 years, especially on the matter of settlement control. This was achieved by guiding the TBM operation to control the main factors that induce soil displacements, namely the face pressure and the closure of the soil-lining void. Nowadays, TBMs can be operated within strict serviceability requirements. However, several mechanisms of the excavation cycle are still not taken into account when estimating the i...

  4. Crime, Education and Peer Pressure


    P. Buonanno


    We present a dynamic two-period model of individual behaviour with heterogeneous agents in which individuals decide how to allocate their disposable time between education, crime and work in the legal sector. Education has a multiple role: it implies higher expected wages in the legal sector, increasing the opportunity cost of committing crime and it has a sort of “civilization” effect that makes more costly to engage in criminal activities. We model this effect by introducing a peer pressure...

  5. The calculation of pressure vessels

    International Nuclear Information System (INIS)

    The calculation guidelines of the Arbeitsgemeinschaft Druckbehaelter (task group for pressure vessels) have been revised with the following objective: conversion to international standards (SI), adaption to the latest state of guidelines for production and testing, revision of the contents of individual regulations. Another target of the cooperating interest groups of producers, operators, and supervisory bodies was a harmonization of the approaches for calculation with other German guidelines, in particular the Technische Regeln fuer Dampfkessel (technical regulations for steam boilers). (orig./RW)

  6. ''Swiss cheese'' models with pressure

    International Nuclear Information System (INIS)

    Local spherically symmetric inhomogeneities are matched to a spatially flat Robertson-Walker background with pressure. In the cases in which the background evolves to an Einstein--de Sitter dust universe, the interior metrics tend with time either to the vacuum Schwarzschild solution or to the spatially flat Tolman dust metrics. The whole construction may be interpreted as the history of the dust-filled ''Swiss cheese'' models

  7. Pressure induced ageing of polymers (United States)

    Emri, I.; Knauss, W. G.


    The nonlinearly viscoelastic response of an amorphous homopolymer is considered under aspects of time dependent free volume behavior. In contrast to linearly viscoelastic solids, this model couples shear and volume deformation through a shift function which influences the rate of molecular relaxation or creep. Sample computations produce all those qualitative features one observes normally in uniaxial tension including the rate dependent formation of a yield point as a consequence of the history of an imposed pressure.

  8. Thermodynamic Pressure/Temperature Transducer Health Check (United States)

    Immer, Christopher D. (Inventor); Eckhoff, Anthony (Inventor); Medelius, Pedro J. (Inventor); Deyoe, Richard T. (Inventor); Starr, Stanley O. (Inventor)


    A device and procedure for checking the health of a pressure transducer in situ is provided. The procedure includes measuring a fixed change in pressure above ambient pressure and a fixed change in pressure below ambient pressure. This is done by first sealing an enclosed volume around the transducer with a valve. A piston inside the sealed volume is increasing the pressure. A fixed pressure below ambient pressure is obtained by opening the valve, driving the piston The output of the pressure transducer is recorded for both the overpressuring and the underpressuring. By comparing this data with data taken during a preoperative calibration, the health of the transducer is determined from the linearity, the hysteresis, and the repeatability of its output. The further addition of a thermometer allows constant offset error in the transducer output to be determined.

  9. High pressure xenon ionization detector

    International Nuclear Information System (INIS)

    A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0 to 30 C. 2 figs

  10. ITER Port Interspace Pressure Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, Juan J [ORNL; Van Hove, Walter A [ORNL


    The ITER Vacuum Vessel (VV) is equipped with 54 access ports. Each of these ports has an opening in the bioshield that communicates with a dedicated port cell. During Tokamak operation, the bioshield opening must be closed with a concrete plug to shield the radiation coming from the plasma. This port plug separates the port cell into a Port Interspace (between VV closure lid and Port Plug) on the inner side and the Port Cell on the outer side. This paper presents calculations of pressures and temperatures in the ITER (Ref. 1) Port Interspace after a double-ended guillotine break (DEGB) of a pipe of the Tokamak Cooling Water System (TCWS) with high temperature water. It is assumed that this DEGB occurs during the worst possible conditions, which are during water baking operation, with water at a temperature of 523 K (250 C) and at a pressure of 4.4 MPa. These conditions are more severe than during normal Tokamak operation, with the water at 398 K (125 C) and 2 MPa. Two computer codes are employed in these calculations: RELAP5-3D Version 4.2.1 (Ref. 2) to calculate the blowdown releases from the pipe break, and MELCOR, Version 1.8.6 (Ref. 3) to calculate the pressures and temperatures in the Port Interspace. A sensitivity study has been performed to optimize some flow areas.

  11. Pressurized water reactor inspection procedures

    International Nuclear Information System (INIS)

    Inspections of the reactor pressure vessels of pressurized water reactors (PWR) so far used to be carried out with different central mast manipulators. For technical reasons, parallel inspections of two manipulators alongside work on the refueling cavity, so as to reduce the time spent on the critical path in a revision outage, are not possible. Efforts made to minimize the inspection time required with one manipulator have been successful, but their effects are limited. Major reductions in inspection time can be achieved only if inspections are run with two manipulators in parallel. The decentralized manipulator built by GEC Alsthom Energie and so far emmployed in boiling water reactors in the USA, Spain, Switzerland and Japan allows two systems to be used in parallel, thus reducing the time required for standard inspection of a pressure vessel from some six days to three days. These savings of approximately three days are made possible without any compromises in terms of positioning by rail-bound systems. During inspection, the reactor refueling cavity is available for other revision work without any restrictions. The manipulator can be used equally well for inspecting standard PWR, PWR with a thermal shield, for inspecting the land between in-core instrumentation nozzles, BWR with and without jet pumps (complementary inspection), and for inspecting core support shrouds. (orig.)

  12. Automated postoperative blood pressure control

    Institute of Scientific and Technical Information of China (English)

    Hang ZHENG; Kuanyi ZHU


    It is very important to maintain the level of mean arterial pressure (MAP).The MAP control is applied in many clinical situations,including limiting bleeding during cardiac surgery and promoting healing for patient's post-surgery.This paper presents a fuzzy controller-based multiple-model adaptive control system for postoperative blood pressure management.Multiple-model adaptive control (MMAC) algorithm is used to identify the patient model,and it is a feasible system identification method even in the presence of large noise.Fuzzy control (FC) method is used to design controller bank.Each fuzzy controller in the controller bank is in fact a nonlinear proportional-integral (PI) controller,whose proportional gain and integral gain are adjusted continuously according to error and rate of change of error of the plant output,resulting in better dynamic and stable control performance than the regular PI controller,especially when a nonlinear process is involved.For demonstration,a nonlinear,pulsatile-flow patient model is used for simulation,and the results show that the adaptive control system can effectively handle the changes in patient's dynamics and provide satisfactory performance in regulation of blood pressure of hypertension patients.

  13. Ultrahigh Temperature Capacitive Pressure Sensor (United States)

    Harsh, Kevin


    Robust, miniaturized sensing systems are needed to improve performance, increase efficiency, and track system health status and failure modes of advanced propulsion systems. Because microsensors must operate in extremely harsh environments, there are many technical challenges involved in developing reliable systems. In addition to high temperatures and pressures, sensing systems are exposed to oxidation, corrosion, thermal shock, fatigue, fouling, and abrasive wear. In these harsh conditions, sensors must be able to withstand high flow rates, vibration, jet fuel, and exhaust. In order for existing and future aeropropulsion turbine engines to improve safety and reduce cost and emissions while controlling engine instabilities, more accurate and complete sensor information is necessary. High-temperature (300 to 1,350 C) capacitive pressure sensors are of particular interest due to their high measurement bandwidth and inherent suitability for wireless readout schemes. The objective of this project is to develop a capacitive pressure sensor based on silicon carbon nitride (SiCN), a new class of high-temperature ceramic materials, which possesses excellent mechanical and electric properties at temperatures up to 1,600 C.

  14. Segmental blood pressure after total hip replacement

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Soelberg, M; Henriksen, Jens Henrik Sahl


    Twenty-nine patients due to have a total hip replacement had their systemic systolic and segmental blood pressures measured prior to operation and 1 and 6 weeks postoperatively. No patients had signs of ischemia. The segmental blood pressure was measured at the ankle and at the toes. A significant...... drop was found in all pressures 1 week postoperatively. The decrease followed the systemic pressure and was restored to normal after 6 weeks. In a group of six patients with preoperatively decreased ankle pressure, a significant transient further decrease in the ankle-toe gradient pressure was found...

  15. Pressure sensor for high temperature fluids

    International Nuclear Information System (INIS)

    A pressure sensor for high temperature fluids (over 500C), to measure the pressure of liquid sodium in pressurized circuits of a fast neutron reactor is presented. It contains a device to reduce heat transfer to the part of the sensor containing the transducer, thus allowing an accurate, sensitive sensor to be used. Heat transfer is reduced by a thin tubular rod which transmits pressure strains to an elastic structure on which extensometers are placed; and a finned radiator around this rod. For a given pressure, tests show that the indicated pressure difference is 25% for a fluid at 23C and for a fluid at 550C

  16. IceBridge Paroscientific L0 Pressure Altimeter Raw Air Pressure (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Paroscientific L0 Pressure Altimeter Raw Air Pressure (IAPRS0) data set contains air pressure readings taken over Antarctica using the...

  17. Pressure safety program Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Borzileri, C.; Traini, M.


    The Lawrence Livermore National Laboratory (LLNL) is a Research and Development facility. Programs include research in: nuclear weapons, energy, environmental, biomedical, and other DOE funded programs. LLNL is managed by the University of California for the Department of Energy. Many research and development programs require the use of pressurized fluid systems. In the early 1960`s, courses were developed to train personnel to safely work with pressurized systems. These courses served as a foundation for the Pressure Safety Program. The Pressure Safety Program is administered by the Pressure Safety Manager through the Hazards Control Department, and responsibilities include: (1) Pressure Safety course development and training, (2) Equipment documentation, tracking and inspections/retests, (3) Formal and informal review of pressure systems. The program uses accepted codes and standards and closely follows the DOE Pressure Safety Guidelines Manual. This manual was developed for DOE by Lawrence Livermore National Laboratory. The DOE Pressure Safety Guidelines Manual defines five (5) basic elements which constitute this Pressure Safety Program. These elements are: (1) A Pressure Safety Manual, (2) A Safety Committee, (3) Personnel who are trained and qualified, (4) Documentation and accountability for each pressure vessel or system, (5) Control of the selection and the use of high pressure hardware.

  18. Measurement component technology ; vol 1, cryogenic pressure measurement technology, high pressure flange seals, hydrogen embrittlement of pressure transducer material, close coupled Vs. remote transducer installation ...

    CERN Document Server

    Hayakawa, K K; Iwata, M M; Lytle, C F; Chrisco, R M; Greenough, C S; Walling, J A


    Measurement component technology ; vol 1, cryogenic pressure measurement technology, high pressure flange seals, hydrogen embrittlement of pressure transducer material, close coupled Vs. remote transducer installation ...

  19. Pressure thrust and pressure shock arrestor (mixer-diffusor device)

    International Nuclear Information System (INIS)

    A mixer-diffusor device for use in nuclear reactors to control the heat and pressure energy resulting from an accident is attached to the end of a hollow conduit from which a gaseous medium such as steam is to be expelled under pressure. The end of the hollow conduit is submerged under the surface of a body of liquid such as water. The mixer-diffusor comprises a conical baffle having an apex extending into the open end of the conduit. A skirt member is positioned around the end of the conduit so than an annular opening is formed between the wall of the conduit and one edge of the skirt member. The skirt member is tapered outwardly at essentially the same angle as the taper of the conical baffle. When the gaseous medium is expelled from the end of the conduit, the gaseous medium flows against and over the conical baffle thereby reducing the thrust forces of the conduit. As the gaseous medium passes the edge of the end of the conduit, the gaseous medium tends to suck the liquid through the annular opening. The liquid is then mixed with the gaseous medium causing the gaseous medium to form a plurality of small bubbles which are expelled from the opening between the skirt and the conical member. In this manner, the gaseous medium is substantially mixed and diffused with the liquid. (auth)

  20. Modelling of pressure loads in a pressure suppression pool

    Energy Technology Data Exchange (ETDEWEB)

    Timperi, A.; Chauhan, M.; Paettikangas, T.; Niemi, J. [VTT Technical Research Centre of Finland (Finland)


    Rapid collapse of a large steam bubble is analyzed by using CFD and FEM calculations. In addition, a 1D code is written which takes into account the finite condensation rate. The 1D simulations are compared with the PPOOLEX experiment COL-01. By adjusting the condensation rate, the calculated pressure peak near the vent outlet could be made same as in the experiment. Scaling of the measured pressure loads to full-scale is studied by dimensional analyses and by review of the analysis of Sonin (1981). The structural response of containment during chugging is studied by using an FEM of containment with simplified geometry and loading which was created based on experimental data. The results are compared to the case in which desynchronization is absent, and chugging occurs simultaneously in every vent pipe. The desynchronized loading is created by giving random initiation times for chugs out of distribution corresponding to the desynchronization time presented by Kukita and Namatame (1985). CFD simulations of the PPOOLEX experiment MIX-03 were performed. In the experiment, clear chugging behavior was observed. In the simulation, the interphasial surface was much more stable and oscillation occurred at a higher frequency than in the experiment. The differences are likely caused by the turbulence model and too coarse numerical mesh, which causes numerical diffusion. (Author)

  1. Preeclampsia and High Blood Pressure During Pregnancy (United States)

    ... AQ FREQUENTLY ASKED QUESTIONS FAQ034 PREGNANCY Preeclampsia and High Blood Pressure During Pregnancy • What is high blood pressure? • What is chronic hypertension? • What is gestational hypertension? • ...

  2. [Effect of dopamine on the portal pressure]. (United States)

    Benko, H; Peschl, L; Schüller, J; Neumayr, A


    1. An infusion of 3 gamma/kg/min dopamine causes a significant increase in the renal plasma flow and the glomerulum filtration rate. This dosage does not cause a change of the mean systolic and arterial pressure. This effect may also be observed in patients with hepatic cirrhosis. 2. The wedged hepatic vein pressure, an indicator for the portal pressure, only shows a slight increase (9,46 +/- 9,41%) as compared to the initial pressure produced by the mentioned dose. Measurements of the spleen pulpa pressure, which likewise indicates the portal pressure, showed an increase of pressure up to 100% due to pressing or coughing. 3. If in the case of bleeding oesophageal varices acute renal failure might develop, the advantage of the effect of dopamine in stimulating the blood flow through the kidneys may be considered more important than the minute danger of a slight increase of the portal pressure, which might provoke haemorrhage. PMID:1220517

  3. Pressure Points: Preventing and Controlling Hypertension (United States)

    ... pressure is to watch what he eats, especially fast food. "African-Americans are very sensitive to salt," he ... reasons to remain on guard include a family history of high blood pressure, lack of regular exercise ...

  4. Calibration of pressure gauge for Cherenkov detector

    CERN Document Server

    Saponjic, Nevena


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

  5. DASH diet to lower high blood pressure (United States)

    ... patientinstructions/000770.htm DASH diet to lower high blood pressure To use the sharing features on this page, ... Hypertension. The DASH diet can help lower high blood pressure and cholesterol and other fats in your blood. ...

  6. High Blood Pressure: Keep the Beat Recipes (United States)

    ... this page please turn Javascript on. Feature: High Blood Pressure Keep the Beat Recipes Past Issues / Fall 2011 ... National Heart, Lung, and Blood Institute To Improve Blood Pressure, Try the DASH Diet If you're one ...

  7. High Blood Pressure: Unique to Older Adults (United States)

    ... e-newsletter! Aging & Health A to Z High Blood Pressure Hypertension Unique to Older Adults This section provides ... care and improve or maintain quality of life. Blood Pressure Targets are Different for Very Old Adults High ...

  8. High blood pressure and eye disease (United States)

    ... page: // High blood pressure and eye disease To use the sharing features ... are sent to the brain. Causes High blood pressure can damage blood vessels in the retina. The higher the blood ...

  9. Segmental blood pressure after total hip replacement

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Soelberg, M; Henriksen, Jens Henrik


    Twenty-nine patients due to have a total hip replacement had their systemic systolic and segmental blood pressures measured prior to operation and 1 and 6 weeks postoperatively. No patients had signs of ischemia. The segmental blood pressure was measured at the ankle and at the toes. A significant...... drop was found in all pressures 1 week postoperatively. The decrease followed the systemic pressure and was restored to normal after 6 weeks. In a group of six patients with preoperatively decreased ankle pressure, a significant transient further decrease in the ankle-toe gradient pressure was found on...... the operated side. None of the patients had symptoms from the lowered pressure. We conclude that in patients without signs of ischemia, the postoperative segmental pressure decrease is reversible and therefore not dangerous....

  10. Measuring Grip Pressure during the Golf Swing. (United States)

    Budney, David R.


    With the use of a special instrumented golf club, grip pressure measurements can be used by the instructor to quantify and discuss the effects of grip pressure in relation to instructional points. (MM)

  11. Fiber Optic Pressure Sensor Array Project (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array System for measuring air flow pressure at multiple points on the skin of aircrafts for Flight...

  12. Fiber Optic Pressure Sensor Array Project (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array for measuring air flow pressure at multiple points on the skin of aircrafts for Flight Load Test...

  13. Pressure Points: Preventing and Controlling Hypertension (United States)

    ... pressure is to watch what he eats, especially fast food. "African-Americans are very sensitive to salt," he ... of food nutrients on blood pressure. It emphasizes consumption of fruits, vegetables and lowfat dairy foods, whole ...

  14. Pressure Drop Measurements on Distillation Columns

    Institute of Scientific and Technical Information of China (English)

    T.J. Cai; M.R. Resetarits


    Pressure drops are of major importance for distillation/absorption columns. This paper mainly discusses how to correctly measure, interpret and use pressure drop data. The possible causes of incorrect pressure drop measurements are studied including the effects of pressure tap dimensions, locations, and vapor condensation etc. The effect of the static head of vapor on the pressure drop data and column pressures is evaluated. Variations of sectional pressure drops along the column are investigated based on the experimental data obtained from commercial size distillation columns at Fractionation Research, Inc. (FRI). For a packed column, it is found that the spacing between the liquid distributor and the top of the bed affects the overall pressure drop measurements, which is confirmed by a fundamental fluid dynamics analysis.

  15. Blood Pressure Patterns May Predict Stroke Risk (United States)

    ... blood pressure reading) of more than 6,700 Dutch adults. Participants were ages 55 to 106 and ... stroke or death from other blood pressure-related diseases up to age 80, the study found. Moderately ...

  16. Safety in the use of pressurized suits

    International Nuclear Information System (INIS)

    This Code of Practice describes the procedures relating to the safe operation of Pressurized Suit Areas and their supporting services. It is directed at personnel responsible for the design and/or operation of Pressurized Suit Areas. (author)

  17. Llano puts pressure on drillers

    Energy Technology Data Exchange (ETDEWEB)

    Flatern, R. von


    An account of technological achievement in deepwater vertical drilling is given in the first of two articles. EEX`s used the Sedco Forex Omega platform to set a drilling depth record of 26,969 ft in 2600 ft of water in the Gulf of Mexico in June 1998. The second reports on technology to support measurements while drilling used to drill the world`s deepest horizontal well in Italy`s Villafortuna Trecate field. Technological innovations in the field of high-pressure composite drilling riser joints are also noted. (UK)

  18. Vertebrate pressure-gradient receivers

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob


    . Recent vertebrates form a continuum from perfect interaural transmission (0 dB in a certain frequency band) and pronounced eardrum directionality (30-40 dB) in the lizards, over somewhat attenuated transmission and limited directionality in birds and frogs, to the strongly attenuated interaural...... transmission and functionally isolated pressure receiver ears in the mammals. Since some of the binaural interaction already takes place at the eardrum in animals with strongly coupled ears, producing enhanced interaural time and level differences, the subsequent neural processing may be simpler. In robotic...

  19. Pressure transducers for cryogenic liquids


    Pavlovskyy I. V.; Kutrakov A. P.; Maryamova I. I.; Druzhinin A. A.


    The developed universal construction of tensoresistive pressure transducer for cryogenic liquids (liquid nitrogen and liquid helium) is described. The study of strain gauges characteristics on the basis of p-type Si whiskers with different boron concentration, mounted on the invar spring elements (beams), in the wide ranges of strain ε=±1,2·10-3 and temperature 4,2-300 К for transducers simulation were carried out. It was shown that using heavily doped silicon strain gages gives the possibili...

  20. Handling Pressures of Community Logic

    DEFF Research Database (Denmark)

    Minbaeva, Dana; Hotho, Jasper; Muratbekova-Touron, Maral;


    relations and interactions with community members can act as social cues that induce and expose individuals to community logics. We subsequently propose that properties of these relations – immediacy and relatedness - will affect individual response strategies towards community logics. We test these ideas......The paper aims at investigating how in pluralistic societies, such as emerging economies and countries in transition, organizational decision-makers respond to pressures of community logics in non-community settings, such as the work place. We theorize that in non-community settings, social...

  1. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana; Birke-Sorensen, Hanne; Kruse, Marie;

    incisions to reduce postoperative wound complications, though the evidence base to support this intervention is limited. The aim of this study was to assess if Negative Pressure Wound Therapy (NPWT) reduces postoperative complications when applied on closed surgical incisions. Method: A systematic review...... seroma formation (52%) compared to standard care. The reduction in wound dehiscence was not statistically significant. The numbers needed to treat were 3 (seroma), 17 (dehiscence), and 25 (infection). Methodical heterogeneity across studies led to downgrading quality of evidence to moderate for infection...

  2. Cataract surgery to lower intraocular pressure

    Directory of Open Access Journals (Sweden)

    Berdahl John


    Full Text Available Cataract and glaucoma are common co morbidities. Cataract surgery is frequently performed in patients with glaucoma. In this study, a review of literature with search terms of cataract, glaucoma and intraocular pressure is followed by evaluation and synthesis of data to determine the effect of cataract surgery on intraocular pressure. Cataract surgery seems to lower intraocular pressure on a sustained basis, especially in patients with higher preoperative intraocular pressure. The mechanism of action of these finds remains speculative.


    CERN Multimedia


    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.


    CERN Multimedia


    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.

  5. Carbon nanotube temperature and pressure sensors (United States)

    Ivanov, Ilia N; Geohegan, David Bruce


    The present invention, in one embodiment, provides a method of measuring pressure or temperature using a sensor including a sensor element composed of a plurality of carbon nanotubes. In one example, the resistance of the plurality of carbon nanotubes is measured in response to the application of temperature or pressure. The changes in resistance are then recorded and correlated to temperature or pressure. In one embodiment, the present invention provides for independent measurement of pressure or temperature using the sensors disclosed herein.

  6. Pressure fluctuations in swirling turbulent flows


    Fauve, S.; Laroche, C; Castaing, B.


    We report measurements of pressure fluctuations in swirling turbulent flows generated in the gap between two rotating coaxial disks. We relate the pressure spectra to the observed flow regimes in the case of co-rotating and counter-rotating disks. In the latter case, we show that the pressure probability density function is strongly non-Gaussian and displays an exponential tail toward low pressures which might be ascribed to intermittent vorticity concentrated on tube-like structures. Similar...

  7. Incentive Effects of Peer Pressure in Organizations


    Kohei Daido


    This paper studies the effects of peer pressure on incentives. We assume that, in addition to the material payoff, each agent's utility includes the psychological payoff from peer pressure generated by a comparison of effort costs. We show that the optimal incentive schemes depend mainly on the degree of peer pressure and of the heterogeneity of agents. Furthermore, we examine the optimal organizational forms in terms of the principal''s intention to make use of the effects of peer pressure.

  8. Pipes under internal pressure and bending

    CERN Document Server

    Catinaccio, A


    This article covers the general behaviour of a straight uniform pipe, with built-in open ends, subject to internal pressure and in plane bending or curvature. It is intended as a summary of the basic equations driving the unintuitive phenomena of bending and instability of pipes under internal pressure. The analysis covers in addition the investigation of opposite pressure stabilisation effects that can be observed in some orthotropic material pipes like composite pressure hoses.

  9. High pressure fiber optic sensor system (United States)

    Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N


    The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

  10. Pressure effects in multiphase binary diffusion couples (United States)

    Subramanyam, Dilip; Notis, Michael R.; Goldstein, Joseph I.


    A systematic study has been carried out of the effect of pressure upon growth kinetics of intermediate phases formed in diffusion couples in the binary systems Ni-Al, U-A1, and U-Cu. Even though applied pressures greater than 100 MPa and long times were investigated little or no pressure effect was observed, in disagreement with previous literature reports. The magnitude of observed pressure effects falls within that expected by closure of Kirkendall porosity.

  11. The role of nutrition for pressure ulcer management: national pressure ulcer advisory panel, European pressure ulcer advisory panel, and pan pacific pressure injury alliance white paper. (United States)

    Posthauer, Mary Ellen; Banks, Merrilyn; Dorner, Becky; Schols, Jos M G A


    Nutrition and hydration play an important role in preserving skin and tissue viability and in supporting tissue repair for pressure ulcer (PrU) healing. The majority of research investigating the relationship between nutrition and wounds focuses on PrUs. This white paper reviews the 2014 National Pressure Ulcer Advisory Panel, European Pressure Ulcer Advisory Panel, and Pan Pacific Pressure Injury Alliance Nutrition Guidelines and discusses nutrition strategies for PrU management. PMID:25775201

  12. 46 CFR 154.452 - External pressure. (United States)


    ... tower and piping, the effect of the partially filled tank, the effect of acceleration and hull deflection, and the local effect of external and internal pressure. P4=0, or the external pressure from the... space containing any portion of a pressure vessel. P3=total compressive load in the tank shell from...

  13. 49 CFR 195.108 - External pressure. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on the pipe must be provided for in designing a pipeline system....

  14. 49 CFR 229.107 - Pressure gauge. (United States)


    ....107 Pressure gauge. (a) Each steam generator shall have an illuminated steam gauge that correctly... the allowed working pressure of the steam generator. (b) Each steam pressure gauge on a steam generator shall have a siphon that prevents steam from entering the gauge. The pipe connection...

  15. 49 CFR 230.35 - Pressure testing. (United States)


    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Pressure Testing of Boilers § 230.35 Pressure testing. The temperature of the steam locomotive boiler shall be raised to at least 70 deg. F any time hydrostatic pressure is applied to the boiler....

  16. Pressurized solid oxide fuel cell testing

    Energy Technology Data Exchange (ETDEWEB)

    Basel, R.A.; Pierre, J.F.


    The goals of the SOFC pressurized test program are to obtain cell voltage versus current (VI) performance data as a function of pressure; to evaluate the effects of operating parameters such as temperature, air stoichiometry, and fuel utilization on cell performance, and to demonstrate long term stability of the SOFC materials at elevated pressures.

  17. A micromachined pressure/flow sensor

    NARCIS (Netherlands)

    Oosterbroek, R.E.; Lammerink, T.S.J.; Berenschot, J.W.; Krijnen, G.J.M.; Elwenspoek, M.C.; Berg, van den A.


    The micromechanical equivalent of a differential pressure flow-sensor, well known in macro mechanics, is discussed. Two separate pressure sensors are used for the device, enabling to measure both, pressure as well as volume flow-rate. An integrated sensor with capacitive read-out as well as a hybrid

  18. How to care for pressure sores (United States)

    Pressure ulcer; Bedsore; Decubitus ulcer ... when pressed. This is a sign that a pressure ulcer is forming. The skin may be warm or ... body fat in the crater. Stage IV: The pressure ulcer has become so deep that there is damage ...

  19. Peer Pressure: An Issue That Crosses Generations. (United States)

    Kittredge, Karen; McCarthy, Alice R.


    Recent research on peer pressure shows that: parents are important to teens, today's teens face unique challenges, and teaching teens to say no does not mean losing friends. The paper presents parenting tips for countering peer pressure, noting the influence of adult peer pressure on children. A sidebar examines the right age to start talking to…

  20. High-speed fiber grating pressure sensors (United States)

    Udd, Eric; Rodriguez, George; Sandberg, Richard L.


    Fiber grating pressure sensors have been used to support pressure measurements associated with burn, deflagration and detonation of energetic materials. This paper provides an overview of this technology and serves as a companion paper to the application of this technology to measuring pressure during high speed impacts.

  1. Statistical analysis of silo wall pressures

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Berntsen, Kasper Nikolaj


    Previously published silo wall pressure measurements during plug flow of barley in alarge concrete silo are re-analysed under the hypothesis that the wall pressures are gamma-distributed.The fits of the gamma distribution type to the local pressure data from each measuring cell are satisfactory.H...

  2. Simple device to determine the pressure applied by pressure clips for the treatment of earlobe keloids

    Directory of Open Access Journals (Sweden)

    Aashish Sasidharan


    Full Text Available Background: Keloids of the ear are common problems. Various treatment modalities are available for the treatment of ear keloids. Surgical excision with intralesional steroid injection along with compression therapy has the least recurrence rate. Various types of devices are available for pressure therapy. Pressure applied by these devices is uncontrolled and is associated with the risk of pressure necrosis. We describe here a simple and easy to use device to measure pressure applied by these clips for better outcome. Objectives: To devise a simple method to measure the pressure applied by various pressure clips used in ear keloid pressure therapy. Materials and Methods: By using a force sensitive resistor (FSR, the pressure applied gets converted into voltage using electrical wires, resistors, capacitors, converter, amplifier, diode, nine-volt (9V cadmium battery and the voltage is measured using a multimeter. The measured voltage is then converted into pressure using pressure voltage graph that depicts the actual pressure applied by the pressure clip. Results: The pressure applied by different clips was variable. The spring clips were adjustable by slight variation in the design whereas the pressure applied by binder clips and magnet discs was not adjustable. Conclusion: The uncontrolled/suboptimal pressure applied by certain pressure clips can be monitored to provide optimal pressure therapy in ear keloid for better outcome.

  3. Effect of pressure on nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Uma D. [Department of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar-263145 (India); Kumar, M., E-mail: [Department of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar-263145 (India)


    A simple theory is proposed to predict the effect of pressure on nanomaterials, which gets support from the Mie-Gruneisen theory of thermal expansivity as formulated by Born and Huang. We considered LiAlSi{sub 2}O{sub 6} to study the effect of pressure in the light of other formulations, viz. Murnaghan, Birch-Murnaghan, Vinet and Kumar. The results obtained are found to present a good agreement with the experimental data as well as other formulations. To confirm the validity of the formulation, we applied the method to study the compression behaviour of a number of nanomaterials, viz. CdSe, Rb{sub 3}C{sub 60}, Ni(20 nm), carbon nanotube, {gamma}-Fe{sub 2}O{sub 3}, {epsilon}-Fe (Hexagonal iron), MgO, CuO, {gamma}-Al{sub 2}O{sub 3} (67 nm), {alpha}-Fe{sub 2}O{sub 3}, {alpha}-Fe (filled nanotube), TiO{sub 2} (anatase), 3C-SiC (30 nm), TiO{sub 2} (rutile phase), Zr{sub 0.1}Ti{sub 0.9}O{sub 2}, AlN (hexagonal), {gamma}-Si{sub 3}N{sub 4}, Ni-filled MWCNT and Fe-filled MWCNT. The results obtained are compared with the experimental data. A good agreement between theory and experiment demonstrates the validity of the present approach.

  4. Atmospheric pressure plasma jet applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.; Herrmann, H.W.; Henins, I.; Selwyn, G.S. [Los Alamos National Lab., NM (United States)


    The atmospheric pressure plasma jet (APPJ) is a non-thermal, high pressure plasma discharge that produces a high velocity effluent stream of highly reactive chemical species. The discharge operates on a feedstock gas (e.g., He/O2/H2O) which flows between two concentric cylindrical electrodes: an outer grounded electrode and an inner electrode powered at 13.56 MHz RF. While passing through the plasma, the feedgas becomes excited, ionized or dissociated by electron impact. The fast-flowing effluent consists of ions and electrons, which are rapidly lost by recombination, highly reactive radicals (e.g., O, OH), and metastable species (e.g., O2). The metastable O2, which is reactive to hydrocarbon and other organic species, has been observed through optical emission spectroscopy to decrease by a factor of 2 from the APPJ nozzle exit to a distance of 10 cm. Unreacted metastable O2, and that which does not impinge on a surface, will then decay back to ordinary ground state O2, resulting in a completely dry, environmentally-benign form of surface cleaning. Applications such as removal of photoresist, oxide films and organic residues from wafers for the electronics industry, decontamination of civilian and military areas and personnel exposed to chemical or biological warfare agents, and paint (e.g., graffiti) removal are being considered.

  5. High Pressure Boiling Water Reactor

    International Nuclear Information System (INIS)

    Some four hundred Boiling Water Reactors (BWR) and Pressurized Water Reactors (PWR) have been in operation for several decades. The presented concept, the High Pressure Boiling Water Reactor (HP-BWR) makes use of the operating experiences. HP-BWR combines the advantages and leaves out the disadvantages of the traditional BWRs and PWRs by taking in consideration the experiences gained during their operation. The best parts of the two traditional reactor types are used and the troublesome components are left out. HP-BWR major benefits are; 1. Safety is improved; -Gravity operated control rods -Large space for the cross formed control rods between fuel boxes -Bottom of the reactor vessel is smooth and is without penetrations -All the pipe connections to the reactor vessel are well above the top of the reactor core -Core spray is not needed -Internal circulation pumps are used. 2. Environment friendly; -Improved thermal efficiency, feeding the turbine with ∼340 oC (15 MPa) steam instead of ∼285 oC (7MPa) -Less warm water release to the recipient and less uranium consumption per produced kWh and consequently less waste is produced. 3. Cost effective, simple; -Direct cycle, no need for complicated steam generators -Moisture separators and steam dryers are inside the reactor vessel and additional separators and dryers can be installed inside or outside the containment -Well proved simple dry containment or wet containment can be used. (author)

  6. Triplets pass their pressure test

    CERN Multimedia


    All the LHC inner triplets have now been repaired and are in position. The first ones have passed their pressure tests with flying colours. The repaired inner triplet at LHC Point 1, right side (1R). Ranko Ostojic (on the right), who headed the team responsible for repairing the triplets, shows the magnet to Robert Zimmer, President of the University of Chicago and of Fermi Research Alliance, who visited CERN on 20th August.Three cheers for the triplets! All the LHC inner triplets have now been repaired and are in position in the tunnel. Thanks to the mobilisation of a multidisciplinary team from CERN and Fermilab, assisted by the KEK Laboratory and the Lawrence Berkeley National Laboratory (LBNL), a solution has been found, tested, validated and applied. At the end of March this year, one of the inner triplets at Point 5 failed to withstand a pressure test. A fault was identified in the supports of two out of the three quadruple magne...

  7. High-pressure microhydraulic actuator

    Energy Technology Data Exchange (ETDEWEB)

    Mosier, Bruce P [San Francisco, CA; Crocker, Robert W [Fremont, CA; Patel, Kamlesh D [Dublin, CA


    Electrokinetic ("EK") pumps convert electric to mechanical work when an electric field exerts a body force on ions in the Debye layer of a fluid in a packed bed, which then viscously drags the fluid. Porous silica and polymer monoliths (2.5-mm O.D., and 6-mm to 10-mm length) having a narrow pore size distribution have been developed that are capable of large pressure gradients (250-500 psi/mm) when large electric fields (1000-1500 V/cm) are applied. Flowrates up to 200 .mu.L/min and delivery pressures up to 1200 psi have been demonstrated. Forces up to 5 lb-force at 0.5 mm/s (12 mW) have been demonstrated with a battery-powered DC-DC converter. Hydraulic power of 17 mW (900 psi@ 180 uL/min) has been demonstrated with wall-powered high voltage supplies. The force and stroke delivered by an actuator utilizing an EK pump are shown to exceed the output of solenoids, stepper motors, and DC motors of similar size, despite the low thermodynamic efficiency.

  8. Pumpesystem for undervannsbrønner


    Baghirov, Tural


    Nowadays,electrical submersible pumping(ESP) is becoming more attractive among artificial lifting methods.The purpose of the submersible pumping is to increase bottom hole pressure. Development of ESPsystems, which are deployed through production tubing is particularly important in Norway, as there are severa lhundreds of subsea wells, which are approaching to the stage, when reservoir pressure is not enough anymore to overcomepressure loss along flowpath, no matter how much was able to decre...

  9. Correct sampling of gas condensate reservoir with liquid drop around the well


    Gebremedhin, Okbit


    In gas-condensate system for an accurate engineering and science computations such as reserves estimation and well testing and analysing a concrete knowledge of phase and fluid phase behaviour is very significant. In typical gas-condensate reservoirs with the decrease of the flowing bottom-hole pressure below the dew point dramatic decrease in gas production occurs. In presence of high pressure and temperature, there is a much higher tendency of complex organic molecules degradation. The ...

  10. High-pressure inactivation of dried microorganisms. (United States)

    Espinasse, V; Perrier-Cornet, J-M; Marecat, A; Gervais, P


    Dried microorganisms are particularly resistant to high hydrostatic pressure effects. In this study, the survival of Saccharomyces cerevisiae was studied under pressure applied in different ways. Original processes and devices were purposely developed in our laboratory for long-term pressurization. Dried and wet yeast powders were submitted to high-pressure treatments (100-150 MPa for 24-144 h at 25 degrees C) through liquid media or inert gas. These powders were also pressurized after being vacuum-packed. In the case of wet yeasts, the pressurization procedure had little influence on the inactivation rate. In this case, inactivations were mainly due to hydrostatic pressure effects. Conversely, in the case of dried yeasts, inactivation was highly dependent on the treatment scheme. No mortality was observed when dried cells were pressurized in a non-aqueous liquid medium, but when nitrogen gas was used as the pressure-transmitting fluid, the inactivation rate was found to be between 1.5 and 2 log for the same pressure level and holding time. Several hypotheses were formulated to explain this phenomenon: the thermal effects induced by the pressure variations, the drying resulting from the gas pressure release and the sorption and desorption of the gas in cells. The highest inactivation rates were obtained with vacuum-packed dried yeasts. In this case, cell death occurred during the pressurization step and was induced by shear forces. Our results show that the mechanisms at the origin of cell death under pressure are strongly dependent on the nature of the pressure-transmitting medium and the hydration of microorganisms. PMID:17573691

  11. Bulkhead pressure measurements in model fill pours

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R.J.; Roettger, J.J.


    The results of a series of model stope pours designed to investigate working pressures on bulkheads during hydraulic pouring of classified tailings backfill are reported. Total bulkhead pressures and fill water pressures were monitored under the condition of a fully saturated backfill. Similitude of the model testing is discussed and equations are developed to estimate bulkhead pressures under prototype conditions. The model results show that good base drainage, combined with a bulkhead setback, can reduce the expected bulkhead pressures to values such that timber or concrete block structures should be capable of supporting a saturated backfill.

  12. Oil point pressure of Indian almond kernels (United States)

    Aregbesola, O.; Olatunde, G.; Esuola, S.; Owolarafe, O.


    The effect of preprocessing conditions such as moisture content, heating temperature, heating time and particle size on oil point pressure of Indian almond kernel was investigated. Results showed that oil point pressure was significantly (P < 0.05) affected by above mentioned parameters. It was also observed that oil point pressure reduced with increase in heating temperature and heating time for both coarse and fine particles. Furthermore, an increase in moisture content resulted in increased oil point pressure for coarse particles while there was a reduction in oil point pressure with increase in moisture content for fine particles.

  13. Multi-Canister overpack design pressure rating

    International Nuclear Information System (INIS)

    The SNF project was directed to increase the MCO pressure rating by the U.S. Department of Energy, Richland Operations Office (RL) unless the action was shown to be cost prohibitive. This guidance was driven by RL's assessment that there was a need to improve margin and reduce risks associated with assumptions supporting the bounding pressure calculation for the MCO Sealing Strategy. Although more recent pressure analyses show a bounding MCO pressure of 50 psig, RL still considers it prudent to retain the pressure margin the 450 psig rating provides. This rating creates a real, clearly definable margin and significantly reduces the risk that the safety basis will be challenged

  14. Pressures involved in making upper edentulous impressions. (United States)

    Rihani, A


    A study was made of the pressures exerted on the upper denture-bearing area in three patients each with a different type of palatal vault. A method of measuring the relative pressures in different regions of the upper denture bearing area was devised. These pressures were registered with the use of manometers while making an impression in close fitting acrylic resin special trays. The results indicated that the main pressure regions during impression making were near the center of the palate and these pressures diminished toward the buccal borders. PMID:7028974

  15. Swim Pressure: Stress Generation in Active Matter


    Takatori, S. C.; W. Yan; Brady, J. F.


    We discover a new contribution to the pressure (or stress) exerted by a suspension of self-propelled bodies. Through their self-motion, all active matter systems generate a unique swim pressure that is entirely athermal in origin. The origin of the swim pressure is based upon the notion that an active body would swim away in space unless confined by boundaries—this confinement pressure is precisely the swim pressure. Here we give the micromechanical basis for the swim stress and use this new ...

  16. Thermodynamic analysis of pressure-quenching process

    International Nuclear Information System (INIS)

    Pressure-induced amorphization of metal alloy is a new subject which has just begun at the Institute of Solid Physics (Russia). The Cd-Sb system has three stoichiometric compounds at atmospheric pressure. CdSb is a stable phase, while Cd3Sb2 and Cd4Sb3 are metastable at room temperature. The addition of Sb to Cd makes the melting temperature of the alloy fall as the pressure increases at lower pressure. So, there exists a critical pressure, which increases with the increasing of content of Sb, and if Sb > 50%, the melting point decreases with an increase of pressure throughout the process. In this study, a Cd43Sb57 matrix alloy was prepared by melting pure cadmium (99.99%) and antimony (99.99%) in an evacuated silica tube. The tube with the alloy was heated to 943K, kept for 5 min at this temperature, then quenched in water to avoid segregation. The specimen was annealed at 523 K for 100 h. The phase transformation of the pressure-quenched specimen was examined by a micro-area diffraction unit at different times, which shows the crystalline samples, treated by the pressure quenching technique, were amorphizated spontaneously at room temperature. It can be seen that the pressure-quenched metastable phase (PQMP) is different from the original phase, and the pressure quenching process results in a new phase transformation different from that at atmospheric pressure

  17. Pressure effect on subtilisin crystallization and solubility (United States)

    Webb, J. N.; Waghmare, R. Y.; Carpenter, J. F.; Glatz, C. E.; Randolph, T. W.


    High pressures (135 and 200 MPa) arrested the crystallization process in unseeded batch crystallizations of subtilisin conducted at 25°C over a period of seven days. Crystallization resumed at the normal atmospheric pressure rate once batches were depressurized and the active soluble enzyme concentration decayed to the same value as seen in atmospheric crystallizations. Solubility experiments conducted at 25°C showed an exponential increase in apparent solubility with pressure. The solubility increased approximately five-fold at 200 MPa. The partial molar volume change of crystallization for this increase in solubility with pressure is +21±1 ml/mol. Solubility changes with pressure are largely responsible for the arrest in crystallization rate at high pressure. Experiments on pH-pressure and ionic strength-pressure interactions showed that the change in apparent solubility is not due to pressure-induced changes in pH and ionic strength. For comparative purposes, solubility data as a function of pressure were collected on lysozyme. A linear dependence of lysozyme solubility with pressure was observed, with a 40% increase in apparent solubility after incubation for seven days at 210 MPa and 25°C.

  18. Materials for pressure vessels and the strength

    International Nuclear Information System (INIS)

    The viewpoint about safety engineering in design, the selection of materials and the effect of environment on materials are studied, taking pressure vessels as the example. The pressure vessels are defined in the enforcement ordinance of the labor safety and hygiene low, and prescribed in the high pressure gas control low and others. The stress of cylindrical and spherical vessels due to internal or external pressure and the stress concentration at flanges and nozzle portions are explained. The structural materials for pressure vessels are different according to gas or liquid contained, temperature and pressure. In case of the pressure vessels for nuclear reactors, the change of material properties due to neutron irradiation must be considered especially. Usually low alloy steels such as A 302B or A 533B lined with austenitic stainless steel by build-up welding are used. The effect of neutron irradiation is monitored with surveillance test pieces. The inspection of pressure vessels is carried out during the manufacture and in service. The pressure boundary for reactor coolant must be designed so as to endure the leak test and hydrostatic pressure test carried out during the life term of nuclear power generation plants. The statistics on the damage of pressure vessels in USA and UK are given. (Kako, I.)

  19. Auscultatory Blood Pressure Measurement—Effect of Pressure on the Head of the Stethoscope


    Londe, Sol; Klitzner, Thomas S.


    Excessive pressure on the stethoscope head in auscultatory blood pressure measurement does not affect systolic blood pressure value but it does erroneously lower diastolic readings and frequently causes the sounds to persist to zero. Consequently, the lightest possible pressure should be placed on the stethoscope head.

  20. Pressure relief device for nuclear power reactor buildings with pressure relief openings

    International Nuclear Information System (INIS)

    The described pressure relief device counteracts the pressure build-up in case of a sudden pressure increase in the reactor hall by opening covered pressure relief openings in such a way that the hermetic sealing of the reactor building can be assured

  1. Recommended sublimation pressure and enthalpy of benzene

    International Nuclear Information System (INIS)

    Highlights: • Sublimation pressures of benzene were measured. • Benzene thermodynamic properties in the state of ideal gas were calculated. • Recommended sublimation pressure and enthalpy of benzene were developed. -- Abstract: Recommended vapor pressures of solid benzene (CAS Registry Number: 71-43-2) which are consistent with thermodynamically related crystalline and ideal-gas heat capacities as well as with properties of the liquid phase at the triple point temperature (vapor pressure, enthalpy of vaporization) were established. The recommended data were developed by a multi-property simultaneous correlation of vapor pressures and related thermal data. Vapor pressures measured in this work using the static method in the temperature range from 233 K to 260 K, covering pressure range from 99 Pa to 1230 Pa, were included in the simultaneous correlation. The enthalpy of sublimation was established with uncertainty significantly lower than the previously recommended values

  2. Foot Plantar Pressure Measurement System: A Review

    Directory of Open Access Journals (Sweden)

    Yufridin Wahab


    Full Text Available Foot plantar pressure is the pressure field that acts between the foot and the support surface during everyday locomotor activities. Information derived from such pressure measures is important in gait and posture research for diagnosing lower limb problems, footwear design, sport biomechanics, injury prevention and other applications. This paper reviews foot plantar sensors characteristics as reported in the literature in addition to foot plantar pressure measurement systems applied to a variety of research problems. Strengths and limitations of current systems are discussed and a wireless foot plantar pressure system is proposed suitable for measuring high pressure distributions under the foot with high accuracy and reliability. The novel system is based on highly linear pressure sensors with no hysteresis.

  3. Glovebox pressure relief and check valve

    Energy Technology Data Exchange (ETDEWEB)

    Blaedel, K.L.


    This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury.

  4. Pressure effects on the femtosecond laser filamentation (United States)

    Qi, Xiexing; Ma, Cunliang; Lin, Wenbin


    We investigate the pressure effects on the propagation of the laser pulse with wavelength of 800 nm by numerical simulations. We consider the effects on the on-axis intensity, the beam radius and the energy of the filament, as well as the on-axis density of plasma. Numerical results show that when the pressures increase, the length, radius and energy of the light filament become shorter, narrower and lower, respectively. Moreover, we find that the length and the radius of filament are approximately inversely proportional to the pressure and the square root of pressure, respectively, and the pulse with shorter duration is easier to be affected by the pressure. We also obtain the conclusion that the plasma is not necessary to generate the filament in gases in various pressures, as stated by Béjot et al. [1] for the case of standard atmosphere pressure.

  5. Effect of pressure on biogas production

    Directory of Open Access Journals (Sweden)

    Ahmet ERYAŞAR


    Full Text Available In facilities in which biogas systems are installed biogas is not produced and consumed simultaneously. Therefore, biogas produced when there is no consumption should be stored. Low pressure gasometers with 1- 1,5 kPa value are preferred in the rural area and when needed pressurizer is added to the system. When the pressure which gas production and usage require is provided by natural ways without usage of an added pressurizer, a respectively high pressure atmosphere can be seen. In this study, the effects of different low pressures on anaerobic fermentation of cattle manure were experimentally analyzed. Fermentation experiment which was carried out with 9 reactors with fed-batch type, 3 parallels in pressures of 19.6 kPa, 9.5 kPa and 1.5 kPa continued 60 days at 35 ºC. The acquired experimental data was subjected to LSD test in P

  6. Intraluminal pressure profiles during flexible ureterorenoscopy

    DEFF Research Database (Denmark)

    Jung, Helene; Osther, Palle J S


    BACKGROUND: Irrigation and instrumentation during ureterorenoscopic procedures may cause increased pressure in the renal pelvis (PP) with potential harmful adverse effects. In order to assess the pressure increases during ureterorenoscopy, we measured the intraluminal renal pelvic pressure during...... ureteroscope and during stone treatment. RESULTS: Baseline PP was mean 10(±4.0) mmHg. During simple ureterorenoscopy, PP was mean 35(±10) mmHg. During stone management the average PP was 54(±18) mmHg and pelvic pressure peaks up to 328 mmHg occurred. In a 5-min standardized period of simple ureterorenoscopy......, 83 pressure peaks >50 mmHg were measured in average per patient (range 2-238). Forced irrigation with a 20 ml syringe resulted in pressure peaks up to 288 mmHg. CONCLUSION: Very high pelvic pressures are obtained during flexible ureterorenoscopy. Taking into consideration that the threshold for...

  7. Glovebox pressure relief and check valve

    International Nuclear Information System (INIS)

    This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury

  8. Interface pressure behavior during painful cuff algometry

    DEFF Research Database (Denmark)

    Khanian, Bahram Manafi; Arendt-Nielsen, Lars; Kjær Petersen, Kristian;


    OBJECTIVE: . Cuff algometry is used for the psychophysical assessment of deep-tissue pain sensitivity. The cuff pressure homogeneity may affect the pain sensitivity assessment and potentially be improved by alternative cuff designs optimizing the pressure distribution. The aim of this study was to...... investigate the relationship between pain sensitivity, inflation pressure, and distribution of interface pressure between the skin and cuff during stimulation with a conventional air tourniquet and a novel tourniquet including a water tube interfacing the air cuff with the skin. METHODS: . Air and water cuff...... stimulations were applied separately on the right lower leg of 12 subjects until the tolerance pain threshold. The inflation pressure was controlled and recorded by a computer-control program, while the interface pressure distribution was measured by a flexible pressure sensor mat located between the cuff and...

  9. Positive pressure breathing during rest and exercise. (United States)

    den Hartog, E A; Heus, R


    The requirements to maintain a positive pressure with respiratory protection during heavy exercise and the effects on ventilation and feelings of discomfort were investigated. Eight male subjects participated, using the respirator system during rest and exercise at about 80% of their individual maximum power. A blower was used at maximum and medium capacity and at two pressure levels (3 and 15 mbar). Additionally, the mouth pressure was used as a feedback for the blower. The blower decreased the fraction of the breathing cycle with negative pressures from 50% (SD 4%) to 15% (SD 10%) during exercise. Negative pressures occurred at all settings of the blower during exercise. Thus, the currently available commercial blower systems do not supply a sufficient airflow to maintain a positive pressure during heavy exercise. Positive pressure breathing did not affect the ventilation and the circulation. But the oxygen consumption was higher with the blower and respirator than without. PMID:12628576

  10. Bearing pad to pressure tube contact simulation

    International Nuclear Information System (INIS)

    Thermal creep strain deformation is a very important pressure tube failure mechanism. During a postulated LOCA (loss of coolant accident) with failure of emergency core injection sys- tem (ECIS), the fuel cladding temperature rapidly increases and the pressure tube becomes completely dry in a few seconds after flow stagnation occurs. Subsequently, the pressure tube circumference is heated by thermal radiation except at the spots where the bearing pads are in direct contact with the pressure tube. Therefore, the localized hot spots are developed on the pressure tube's inner surface under the bearing pads. The main objective of this paper is to evaluate the local thermal-mechanical deformation of a pressure tube in a CANDU reactor and to investigate the fuel channel integrity under localized contact between bearing pad and pressure tube. Furthermore, the mechanistic models are validated against the experimental works per- formed at WRL (Whiteshell research laboratory). Calculations are performed using the finite element method in which the heat, thermal mechanical and creep strain equations are solved, simultaneously. According to the experimental set up, the heat conduction from bearing pads to the inner surface of the pressure tube with appropriate convective and radiation boundary conditions has been simulated. Furthermore, the thermal creep strain deformation has been obtained for when the pressure tube is still under operational condition. It is observed that the pressure tube thermal strain will occur if sufficient high temperature is reached however, depending on the severity of flow degradation in the fuel channel, these localized hot spots could represent a potential creep strain failure of the pressure tube. Whether the pressure tube would fail at these hot spots before contacting the calandria tube depends on the localized temperature and experienced pressure transients. Sensitivity analysis is performed in order to evaluate the contact conductance, the

  11. Cataract surgery and intraocular pressure. (United States)

    Melancia, Diana; Abegão Pinto, Luis; Marques-Neves, Carlos


    Cataract surgery is one of the most performed surgeries in the developed world. In addition to its significant impact on visual acuity, phacoemulsification has been hailed as a potential intraocular pressure (IOP)-lowering procedure. While current evidence suggests an overall significant and sustained decrease in IOP to exist after cataract surgery, the specific ocular characteristics that could help predict which patients are likely to benefit from this IOP-lowering effect remain unclear. This definition is important in glaucoma patients if this surgery is to be used in the treatment for this disease. Our review aims to summarize the literature on the subject, depicting possible mechanisms behind this IOP decrease, which type of patients are more likely to benefit from this surgery for IOP-lowering purposes and ultimately help optimizing disease management for the increasing number of patients with concomitant glaucoma and cataract. PMID:25765255

  12. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana

    Women with a pre-gestational body mass index (BMI) above 30 kg/m2 giving birth by caesarean section are at high risk of surgical wound infection compared with women with a BMI below 30 kg/m2. Incisional Negative Pressure Wound Therapy (iNPWT) is one strategy to reduce the rate of surgical wound...... infection. However, the treatment is relatively costly compared to standard postoperative dressings and thus it was important to consider the rationale for using iNPWT before introducing the treatment in a clinical setting. This thesis assesses the current evidence of whether iNPWT reduces post......-surgical wound complications when applied to closed surgical incisions. The meta-analysis showed that iNPWT appears to reduce the risk of post-surgical wound infection and seroma formation in high-risk wounds compared with standard postoperative dressings in selected surgical procedures. The thesis comprises a...

  13. Anthropic pressures on Egadi Islands

    International Nuclear Information System (INIS)

    The Egadi Islands, like most Mediterranean islets, have radically changed the traditional lifestyle and the economic development model, based for centuries on the almost self-sufficient resources and production activities, mostly related to the sea (fishing and fish processing) and to the land. During the second half of the 1900., the development of transport radically transformed this model to make smaller islands, at least those closest to the coast, more tightly interconnected and dependent on the mainland. In particular, in Favignana, which is the most populous island and very close to the coast, the traditional activities tourism have led to a strong anthropic pressure concentrated in a few months of the year (summer) on the one hand, and a reduction of the resident population during the winter months on the other, with a serious impact on the care of the land

  14. Swim pressure of active matter (United States)

    Takatori, Sho; Yan, Wen; Brady, John; Caltech Team


    Through their self-motion, all active matter systems generate a unique ``swim pressure'' that is entirely athermal in origin. This new source for the active stress exists at all scales in both living and nonliving active systems, and also applies to larger organisms where inertia is important (i.e., the Stokes number is not small). Here we explain the origin of the swim stress and develop a simple thermodynamic model to study the self-assembly and phase separation in active soft matter. Our new swim stress perspective can help analyze and exploit a wide class of active soft matter, from swimming bacteria and catalytic nanobots, schools of fish and birds, and molecular motors that activate the cellular cytoskeleton.

  15. Influence of residual stresses on failure pressure of cylindrical pressure vessels

    Institute of Scientific and Technical Information of China (English)

    M. Jeyakumar; T. Christopher


    The utilization of pressure vessels in aerospace applications is manifold. In this work, finite element analysis (FEA) has been carried out using ANSYS software package with 2D axisym-metric model to access the failure pressure of cylindrical pressure vessel made of ASTM A36 carbon steel having weld-induced residual stresses. To find out the effect of residual stresses on failure pressure, first an elasto-plastic analysis is performed to find out the failure pressure of pressure vessel not having residual stresses. Then a thermo-mechanical finite element analysis is performed to assess the residual stresses developed in the pressure vessel during welding. Finally one more elasto-plastic analysis is performed to assess the effect of residual stresses on failure pressure of the pressure vessel having residual stresses. This analysis indicates reduction in the failure pressure due to unfavorable residual stresses.

  16. Mini pressurized logistics module (MPLM) (United States)

    Vallerani, E.; Brondolo, D.; Basile, L.


    The MPLM Program was initiated through a Memorandum of Understanding (MOU) between the United States' National Aeronautics and Space Administration (NASA) and Italy's ASI, the Italian Space Agency, that was signed on 6 December 1991. The MPLM is a pressurized logistics module that will be used to transport supplies and materials (up to 20,000 lb), including user experiments, between Earth and International Space Station Alpha (ISSA) using the Shuttle, to support active and passive storage, and to provide a habitable environment for two people when docked to the Station. The Italian Space Agency has selected Alenia Spazio to develop MPLM modules that have always been considered a key element for the new International Space Station taking benefit from its design flexibility and consequent possible cost saving based on the maximum utilization of the Shuttle launch capability for any mission. In the frame of the very recent agreement between the U.S. and Russia for cooperation in space, that foresees the utilization of MIR 1 hardware, the Italian MPLM will remain an important element of the logistics system, being the only pressurized module designed for re-entry. Within the new scenario of anticipated Shuttle flights to MIR 1 during Space Station phase 1, MPLM remains a candidate for one or more missions to provide MIR 1 resupply capabilities and advanced ISSA hardware/procedures verification. Based on the concept of Flexible Carriers, Alenia Spazio is providing NASA with three MPLM flight units that can be configured according to the requirements of the Human-Tended Capability (HTC) and Permanent Human Capability (PHC) of the Space Station. Configurability will allow transportation of passive cargo only, or a combination of passive and cold cargo accommodated in R/F racks. Having developed and qualified the baseline configuration with respect to the worst enveloping condition, each unit could be easily configured to the passive or active version depending upon the

  17. Reactor pressure vessel thermal annealing

    International Nuclear Information System (INIS)

    The steel plates and/or forgings and welds in the beltline region of a reactor pressure vessel (RPV) are subject to embrittlement from neutron irradiation. This embrittlement causes the fracture toughness of the beltline materials to be less than the fracture toughness of the unirradiated material. Material properties of RPVs that have been irradiated and embrittled are recoverable through thermal annealing of the vessel. The amount of recovery primarily depends on the level of the irradiation embrittlement, the chemical composition of the steel, and the annealing temperature and time. Since annealing is an option for extending the service lives of RPVs or establishing less restrictive pressure-temperature (P-T) limits; the industry, the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC) have assisted in efforts to determine the viability of thermal annealing for embrittlement recovery. General guidance for in-service annealing is provided in American Society for Testing and Materials (ASTM) Standard E 509-86. In addition, the American Society of Mechanical Engineers (ASME) Code Case N-557 addresses annealing conditions (temperature and duration), temperature monitoring, evaluation of loadings, and non-destructive examination techniques. The NRC thermal annealing rule (10 CFR 50.66) was approved by the Commission and published in the Federal Register on December 19, 1995. The Regulatory Guide on thermal annealing (RG 1.162) was processed in parallel with the rule package and was published on February 15, 1996. RG 1.162 contains a listing of issues that need to be addressed for thermal annealing of an RPV. The RG also provides alternatives for predicting re-embrittlement trends after the thermal anneal has been completed. This paper gives an overview of methodology and recent technical references that are associated with thermal annealing. Results from the DOE annealing prototype demonstration project, as well as NRC activities related to the

  18. An eHealth System for Pressure Ulcer Risk Assessment Based on Accelerometer and Pressure Data


    Dieter Hayn; Markus Falgenhauer; Jürgen Morak; Karin Wipfler; Viktoria Willner; Walter Liebhart; Günter Schreier


    Pressure ulcers are a common skin disease which is associated with pain, reduced autonomy, social isolation, and reduced quality of life. There are several systems for monitoring of pressure ulcer-related risk factors on the market, but up to now no satisfactory solution is available, especially for people with medium pressure ulcer risk. We present a novel pressure ulcer risk assessment and prevention system, which combines the advantages of accelerometer and pressure sensors for monitoring ...

  19. Soil pressures at the cutting wheel and the pressure bulkhead of an EPB-shield


    Bezuijen, Adam; Talmon, AM


    Soil pressureswere measured on both sides of the cutterwheel of an EPB-shield during tunnelling in saturated sand, using foam for soil conditioning. The measured pressures are compared with the pressures at the pressure bulkhead. The pressures are not purely hydrostatic but the results are also influenced by the yield strength of the foam mixture and the effective stresses. At the lowest positions, the sensors sometimes measured effective stresses. This led to peaks in the pressures measured....

  20. Comparative Study of Pressure-Induced Germination of Bacillus subtilis Spores at Low and High Pressures


    Wuytack, Elke Y.; Boven, Steven; Michiels, Chris W.


    We have studied pressure-induced germination of Bacillus subtilis spores at moderate (100 MPa) and high (500 to 600 MPa) pressures. Although we found comparable germination efficiencies under both conditions by using heat sensitivity as a criterion for germination, the sensitivity of pressure-germinated spores to some other agents was found to depend on the pressure used. Spores germinated at 100 MPa were more sensitive to pressure (>200 MPa), UV light, and hydrogen peroxide than were those g...

  1. Solenoid valves in the pressurizer systems of pressurized water reactors. Magnetventile im Druckhaltesystem von Druckwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Jocham, H. (Herion-Werke KG, Fellbach (Germany, F.R.))


    The safe functioning of the pressurizer system is a very important feature in the safety of the primary systems of nuclear power plants equipped with pressurized water reactors. The decisive units determining the reliability of the pressurizer are the solenoid actuated valves employed as spray systems for pressure control. These spray valves are components of the primary system and, in a way analogous to the reactor pressure vessel, must satisfy the most stringent safety and quality criteria. (orig.).

  2. Can subglottal pressure be estimated from intra-oral pressure in speech and singing ?


    Henrich, Nathalie; Lagier, Aude; Amy De La Bretèque, Benoit; Giovanni, Antoine


    International audience The direct measurement of subglottal pressure is challenging, because it requires a very invasive approach. It consists in placing a pressure transducer below the glottis by tracheal puncture between the cricoïd cartilage and the trachea first ring. Other methods have been proposed, which estimate the subglottal pressure using less invasive approaches. The most common one is to estimate subglottal pressure from intra-oral pressure measured during the closed phase of ...

  3. Prediction of pressure tube ballooning under non-uniform circumferential temperature gradients and high internal pressure

    International Nuclear Information System (INIS)

    In some accident scenarios in CANDU reactors the pressure tube is expected to reach sufficiently high temperature at high internal pressure such that the pressure tube expands radially, i.e., the pressure tube balloons.Under these conditions it is of importance to the assessment of fuel channel integrity to be able to accurately predict the timing and extent of pressure tube ballooning. If the circumferential temperature gradient on the pressure tube is non-uniform, the resulting transverse hoop stress is non-uniform and the pressure tube experiences a non-uniform ballooning. This could result in a failure of the pressure tube before it balloons into contact with the surrounding calandria tube. The fuel channel integrity code SMARTT (Simulation Method for Azimuthal and Radial Temperature Transients) is used to predict the ballooning of CANDU Zr-2.5wt%Nb pressure tubes. The pressure tube strain rate calculation in SMARTT was extracted and used as the basis for the code PTSTRAIN which was constructed to model pressure tube ballooning with the temperature of the pressure tube and the internal pressure specified as the boundary conditions for the calculation. The main objectives of this paper are to describe the comparison of the predictions of this code against two different sets of experiments which were performed with defected and non-defected pressure tubes, and to provide further validation of the pressure tube ballooning model against independent experiments. (author)

  4. Pressure equivalents in industrial gas pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Metel' kov, V.P.


    Pressure equivalence is a mathematical concept used to explain action and load parameters for pipelines. These two parameters are congruent to pressures encountered in pipelines. The research examined pressure equivalence in 820 by 8 millimeter pipelines in the Samotlor region and took into account the influence of support jams during first and second category jamming. It was determined that the absolute dimensions to pressure pulsations were significantly larger than plus or minus ten percent from (Prab) and even exceeded (Prab) in certain instances. The ratios at which (Prab) can be exceeded vary with relation to the jam supports and the maximum variations stem from yield in the metal pipelines themselves. The above concepts can be used to study the effects of pressure equivalence upon loads and pressures of Samotlor field pipelines and to select appropriate pipeline planning and construction methods. The conclusions drawn are valid for industrial surface pipelines used at below limit pressures. Annular and daily temperature variations in the outside air are considered with regard to their effect upon the pressure equivalence within the lower sections of the pipeline. Deviations here have been noted to exceed (formula). It was observed that in the case of underground pipelines, operated at below limit pressures, pressure equivalence occured in the upper section of the pipeline.

  5. Accuracy of the blood pressure measurement. (United States)

    Rabbia, F; Del Colle, S; Testa, E; Naso, D; Veglio, F


    Blood pressure measurement is the cornerstone for the diagnosis, the treatment and the research on arterial hypertension, and all of the decisions about one of these single aspects may be dramatically influenced by the accuracy of the measurement. Over the past 20 years or so, the accuracy of the conventional Riva-Rocci/Korotkoff technique of blood pressure measurement has been questioned and efforts have been made to improve the technique with automated devices. In the same period, recognition of the phenomenon of white coat hypertension, whereby some individuals with an apparent increase in blood pressure have normal, or reduced, blood pressures when measurement is repeated away from the medical environment, has focused attention on methods of measurement that provide profiles of blood pressure behavior rather than relying on isolated measurements under circumstances that may in themselves influence the level of blood pressure recorded. These methodologies have included repeated measurements of blood pressure using the traditional technique, self-measurement of blood pressure in the home or work place, and ambulatory blood pressure measurement using innovative automated devices. The purpose of this review to serve as a source of practical information about the commonly used methods for blood pressure measurement: the traditional Riva-Rocci method and the automated methods. PMID:17016412

  6. Heated-Pressure-Ball Monopropellant Rocket Engine (United States)

    Greene, William D.


    A recent technology disclosure presents a concept for a monopropellant thermal spacecraft thruster that would feature both the simplicity of a typical prior pressure-fed propellant supply system and the smaller mass and relative compactness of a typical prior pump-fed system. The source of heat for this thruster would likely be a nuclear- fission reactor. The propellant would be a cryogenic fluid (a liquefied low-molecular-weight gas) stored in a tank at a low pressure. The propellant would flow from the tank, through a feedline, into three thick-walled spherical tanks, denoted pressure balls, that would be thermally connected to the reactor. Valves upstream and downstream of the pressure balls would be operated in a three-phase cycle in which propellant would flow into one pressure ball while the fluid underwent pressurization through heating in another ball and pressurized propellant was discharged from the remaining ball into the reactor. After flowing through the reactor, wherein it would be further heated, the propellant would be discharged through an exhaust nozzle to generate thrust. A fraction of the pressurized gas from the pressure balls would be diverted to maintain the desired pressure in the tank.

  7. Modeling and diagnostic techniques applicable to the analysis of pressure noise in pressurized water reactors and pressure-sensing systems

    International Nuclear Information System (INIS)

    Pressure noise data from a PWR are interpreted by means of a computer-implemented model. The model's parameters, namely hydraulic impedances and noise sources, are either calculated or deduced from fits to data. Its accuracy is encouraging and raises the possibility of diagnostic assistance for nuclear plant monitoring. A number of specific applications of pressure noise in the primary system of a PWR and in a pressure sensing system are suggested

  8. Modeling Scala Media as a Pressure Vessel (United States)

    Lepage, Eric; Olofsson, A.˚Ke


    The clinical condition known as endolymphatic hydrops is the swelling of scala media and may result in loss in hearing sensitivity consistent with other forms of low-frequency biasing. Because outer hair cells (OHCs) are displacement-sensitive and hearing levels tend to be preserved despite large changes in blood pressure and CSF pressure, it seems unlikely that the OHC respond passively to changes in static pressures in the chambers. This suggests the operation of a major feedback control loop which jointly regulates homeostasis and hearing sensitivity. Therefore the internal forces affecting the cochlear signal processing amplifier cannot be just motile responses. A complete account of the cochlear amplifier must include static pressures. To this end we have added a third, pressure vessel to our 1-D 140-segment, wave-digital filter active model of cochlear mechanics, incorporating the usual nonlinear forward transduction. In each segment the instantaneous pressure is the sum of acoustic pressure and global static pressure. The object of the model is to maintain stable OHC operating point despite any global rise in pressure in the third chamber. Such accumulated pressure is allowed to dissipate exponentially. In this first 3-chamber implementation we explore the possibility that acoustic pressures are rectified. The behavior of the model is critically dependent upon scaling factors and time-constants, yet by initial assumption, the pressure tends to accumulate in proportion to sound level. We further explore setting of the control parameters so that the accumulated pressure either stays within limits or may rise without bound.

  9. Statistical analysis of silo wall pressures

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Berntsen, Kasper Nikolaj

    Previously published silo wall pressure measurements during plug flow of barley in alarge concrete silo are re-analysed under the hypothesis that the wall pressures are gamma-distributed.The fits of the gamma distribution type to the local pressure data from each measuring cell are satisfactory.......However, the estimated parameters of the gamma distributions turn out to be significantly inhomogeneous overthe silo wall surface. This inhomogeneity is attributed to the geometrical imperfections of the silo wall.Motivated by the engineering importance of the problem a mathematical model for constructing...... astochastic gamma-type continuous pressure field is given. The model obeys the necessary equilibrium conditionsof the wall pressure field and reflects the spatial correlation properties as estimated from simultaneouslymeasured pressures at different locations along a horizontal perimeter....

  10. Sources of Pressure in Titan's Plasma Environment

    CERN Document Server

    Achilleos, N; Bertucci, C; Guio, P; Romanelli, N; Sergis, N


    In order to analyze varying plasma conditions upstream of Titan, we have combined a physical model of Saturn's plasmadisk with a geometrical model of the oscillating current sheet. During modeled oscillation phases where Titan is furthest from the current sheet, the main sources of plasma pressure in the near-Titan space are the magnetic pressure and, for disturbed conditions, the hot plasma pressure. When Titan is at the center of the sheet, the main source is the dynamic pressure associated with Saturn's cold, subcorotating plasma. Total pressure at Titan (dynamic plus thermal plus magnetic) typically increases by a factor of five as the current sheet center is approached. The predicted incident plasma flow direction deviates from the orbital plane of Titan by < 10 deg. These results suggest a correlation between the location of magnetic pressure maxima and the oscillation phase of the plasmasheet.

  11. Beam-induced tensor pressure tokamak equilibria

    International Nuclear Information System (INIS)

    D-shaped tensor pressure tokamak equilibria induced by neutral-beam injection are computed. The beam pressure components are evaluated from the moments of a distribution function that is a solution of the Fokker-Planck equation in which the pitch-angle scattering operator is ignored. The level-psub(perpendicular) contours undergo a significant shift away from the outer edge of the device with respect to the flux surfaces for perpendicular beam injection into broad-pressure-profile equilibria. The psub(parallel) contours undergo a somewhat smaller inward shift with respect to the flux surfaces for both parallel and perpendicular injection into broad-pressure-profile equilibria. For peaked-pressure-profile equilibria, the level pressure contours nearly co-incide with the flux surfaces. (author)

  12. Experimental installation with pressurized fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, W.; Szwarc, W.; Jurek, K.; Prokop, A. (Politechnika Warszawska (Poland). Instytut Techniki Cieplnej)


    Describes a test installation with a 3 MW pressurized fluidized bed boiler. The installation was commissioned at the Institute of Heat Engineering at the Technical University in Warsaw. Predesign assumptions and the lay-out of the installation are given. A schematic diagram of the pressurized (0.6 MPa) fluidized bed boiler with an inner diameter of 1.4 m and a total height of 5.45 m is shown. The fuel feeding system consists of a coal and adsorbent container, two feeders and an air jet pump for pneumatic transport. A water type boiler is integrated into the pressure vessel. Flue gas cyclones are also integrated into a separate pressure vessel. The computerized control system and instrumentation are described. Temperatures, pressures, pressure differences, rotational speeds and the chemical composition of gases are monitored.

  13. Gravitational Pressure and the Accelerating Universe

    CERN Document Server

    Castello-Branco, K H C


    In the context of the teleparallel equivalent of general relativity, we apply a definition for an energy-momentum tensor that naturally arises in this framework. Specially, that quantity leads to a simple definition of pressure that includes the pressure of matter, the "vacuum pressure" (due to a cosmological constant) and, moreover, the pressure of the \\textit{gravitational} field itself. We computed that total pressure on the cosmological apparent horizon of a Friedmann-Robertson-Walker universe. In particular, we considered a spatially flat universe. In this case, by resorting to the current observational data on the cosmological observables we have found that pressure is negative and the corresponding energy density associated to it is so close to the actual \\textit{critical density} of the universe.

  14. High-pressure torsion of hafnium

    International Nuclear Information System (INIS)

    Pure Hf (99.99%) is processed by high-pressure torsion (HPT) under pressures of 4 and 30 GPa to form an ultrafine-grained structure with a gain size of ∼180 nm. X-ray diffraction analysis shows that, unlike Ti and Zr, no ω phase formation is detected after HPT processing even under a pressure of 30 GPa. A hydride formation is detected after straining at the pressure of 4 GPa. The hydride phase decomposes either by application of a higher pressure as 30 GPa or by unloading for prolong time after HPT processing. Microhardness, tensile and bending tests show that a high hardness (360 Hv) and an appreciable ductility (8%) as well as high tensile and bending strength (1.15 and 2.75 GPa, respectively) are achieved following the high-pressure torsion.

  15. Prevention and treatment of pressure ulcers. (United States)

    Thomas, David R


    Pressure ulcers are complex chronic wounds for which no gold standard for prevention or treatment has yet been established. Several attempts at developing guidelines has been undertaken by different organizations. Pressure ulcers are devastating comorbidities for patients and difficult to prevent or manage. Whether or not pressure ulcers are preventable remains controversial. The strategy for prevention includes recognizing the risk, decreasing the effects of pressure, assessing nutritional status, avoiding excessive bed rest and prolonged sitting, and preserving the integrity of the skin. The principles of treatment of pressure ulcers include assessing severity, reducing pressure, friction and shear forces, optimizing local wound care, removing necrotic debris, managing bacterial contamination, and correcting nutritional deficits. PMID:16413435

  16. Commonwealth Edison Company pressure locking test report

    Energy Technology Data Exchange (ETDEWEB)

    Bunte, B.D.; Kelly, J.F.


    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology.

  17. Ballooning of CANDU pressure tubes. Model assessment

    International Nuclear Information System (INIS)

    The transient creep equations used to analyze the possible ballooning and failure of Zr-2.5% Nb pressure tubes during a loss-of-coolant accident (LOCA) were developed and verified using as-received Zr-2.5% Nb pressure tube material. But in a CANDU reactor, the pressure tubes absorb deuterium and are exposed to a continuous neutron fluence. Consequently, a literature survey was done to determine how irradiation damage and deuterium might affect the creep rate and ductility of Zr-2.5% Nb pressure tubes in the temperature range from 600 to 800 degrees C. It was found that irradiation damage, dissolved deuterium and deuteride blisters could possibly affect the creep rate and ductility of ZR-2.5% Nb pressure tubes in this temperature range, but deuteride platelets are expected to have little effect. Further tests are required to determine the effect of irradiation damage and deuterium on the creep rate and ductility of pressure tubes

  18. Organic Electroluminescent Sensor for Pressure Measurement

    Directory of Open Access Journals (Sweden)

    Tomohide Niimi


    Full Text Available We have proposed a novel concept of a pressure sensor called electroluminescent pressure sensor (ELPS based on oxygen quenching of electroluminescence. The sensor was fabricated as an organic light-emitting device (OLED with phosphorescent dyes whose phosphorescence can be quenched by oxygenmolecules, and with a polymer electrode which permeates oxygen molecules. The sensor was a single-layer OLED with Platinum (II octaethylporphine (PtOEP doped into poly(vinylcarbazole (PVK as an oxygen sensitive emissive layer and poly(3,4-ethylenedioxythiophene mixed with poly(styrenesulfonate (PEDOT:PSS as an oxygen permeating polymer anode. The pressure sensitivity of the fabricated ELPS sample was equivalent to that of the sensor excited by an illumination light source. Moreover, the pressure sensitivity of the sensor is equivalent to that of conventional pressure-sensitive paint (PSP, which is an optical pressure sensor based on photoluminescence.

  19. Pore pressure enhancements observed on Rio Blanco

    International Nuclear Information System (INIS)

    Measurements were made of the change of in situ pore pressures and the associated accelerations in the saturated clayey silts (ML) of Fawn Creek and Black Sulphur Valleys at 2.1, 4, 7, and 10 km from surface zero. The early pore pressure changes correlated well with accelerations while the later values correlated better with velocities. The pressure changes ranged from 17.1 to 0.36 psi for the peak pressures and from 1.7 to 0.10 psi for the average pressure increases 10 sec after the detonation. Pretest estimates indicated that liquefaction was considered probable but it was not observed and the pore pressure increases were one-quarter or less than those associated with this phenomenon. (auth)

  20. Hydrogen storage in insulated pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S.M.; Garcia-Villazana, O. [Lawrence Livermore National Lab., CA (United States)


    Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current analysis and experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.

  1. Seismic induced earth pressures in buried vaults

    International Nuclear Information System (INIS)

    The magnitude and distribution of earth pressures acting on buried structures and induced by a seismic event are considered in this paper. A soil-structure-interaction analysis is performed for typical Department of Energy high level waste storage tanks using a lumped parameter model. The resulting soil pressure distributions are determined and compared with the static soil pressure to assess the design significance of the seismic induced soil pressures. It is found that seismic pressures do not control design unless the peak ground acceleration exceeds about 0.3 G. The effect of soil non linearities (resulting from local soil failure) are also found to have little effect on the predictions of the seismic response of the buried structure. The seismic induced pressures are found to be very similar to those predicted using the elastic model in ASCE 4-86

  2. Pressurized waterproof case for electronic device

    KAUST Repository

    Berumen, Michael L.


    The pressurized waterproof case for an electronic device is particularly adapted for the waterproof containment and operation of a touch-screen computer or the like therein at some appreciable water depth. The case may be formed as an enclosure having an open top panel or face covered by a flexible, transparent membrane or the like for the operation of the touch-screen device within the case. A pressurizing system is provided for the case to pressurize the case and the electronic device therein to slightly greater than ambient in order to prevent the external water pressure from bearing against the transparent membrane and pressing it against the touch screen, thereby precluding operation of the touch screen device within the case. The pressurizing system may be a small gas cartridge (e.g., CO2), or may be provided from an external source, such as the diver\\'s breathing air. A pressure relief valve is also provided.

  3. Commonwealth Edison Company pressure locking test report

    International Nuclear Information System (INIS)

    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology

  4. Application of adaptive fuzzy control technology to pressure control of a pressurizer

    Institute of Scientific and Technical Information of China (English)

    YANG Ben-kun; BIAN Xin-qian; GUO Wei-lai


    A pressurizer is one of important equipment in a pressurized water reactor plant. It is used to maintain the pressure of primary coolant within allowed range because the sharp change of coolant pressure affects the security of reactor,therefor,the study of pressurizer's pressure control methods is very important. In this paper, an adaptive fuzzy controller is presented for pressure control of a pressurizer in a nuclear power plant. The controller can on-line tune fuzzy control rules and parameters by self-learning in the actual control process, which possesses the way of thinking like human to make a decision. The simulation results for a pressurized water reactor plant show that the adaptive fuzzy controller has optimum and intelligent characteristics, which prove the controller is effective.

  5. Pressurization rate effect on ligament rupture and burst pressures of cracked steam generator tubes

    International Nuclear Information System (INIS)

    The question of whether ligament rupture pressure or unstable burst pressure may vary significantly with pressurization rate at room temperature arose from the results of pressure tests by industry on tubes with machined part-throughwall notches. Slow (quasi-static) and fast 14 MPa/s (2000 psi/s) pressurization rate tests on specimens with nominally the same notch geometry appeared to show a significant effect of the rate of pressurization on the unstable burst pressure. Unfortunately, the slow and fast loading rate tests were conducted following two different test procedures, which could confound the results. The current series of tests were conducted on a variety of specimen geometries using a consistent test procedure to better establish the effect of pressurization rate on ligament rupture and burst pressures. (author)

  6. Negative pressure wound therapy: clinical utility


    Sandoz H


    Heidi Sandoz Accelerate CIC, Mile End Hospital, London, UK Abstract: Negative pressure wound therapy (NPWT), also known as topical negative pressure therapy, has been increasingly used in health care for the management of a wide variety of wounds over the last 2–3 decades. It is an advanced therapy that can be helpful to accelerate wound healing in both acute and chronic wounds by delivering negative pressure (suction) to the wound bed. More recent advancements in the application of NP...

  7. Blood Pressure Percentiles for School Children


    İsmail Özanli; Sebahat Tülpar; Yunus Yılmaz; Fatih Yıldız


    Objective: The prevalence of hypertension in childhood and adolescence is gradually increasing. We aimed to in­vestigate the blood pressure (BP) values of children aged 7-18 years. Methods: This study was conducted in a total of 3375 (1777 females, 1598 males) children from 27 schools. Blood pressures of children were measured using sphyg­momanometer appropriate to arm circumference. Results: A positive relationship was found between sys­tolic blood pressure (SBP) and diastolic blood pr...

  8. Fiber bundle model under fluid pressure (United States)

    Amitrano, David; Girard, Lucas


    Internal fluid pressure often plays an important role in the rupture of brittle materials. This is a major concern for many engineering applications and for natural hazards. More specifically, the mechanisms through which fluid pressure, applied at a microscale, can enhance the failure at a macroscale and accelerate damage dynamics leading to failure remains unclear. Here we revisit the fiber bundle model by accounting for the effect of fluid under pressure that contributes to the global load supported by the fiber bundle. Fluid pressure is applied on the broken fibers, following Biot's theory. The statistical properties of damage avalanches and their evolution toward macrofailure are analyzed for a wide range of fluid pressures. The macroscopic strength of the new model appears to be strongly controlled by the action of the fluid, particularly when the fluid pressure becomes comparable with the fiber strength. The behavior remains consistent with continuous transition, i.e., second order, including for large pressure. The main change concerns the damage acceleration toward the failure that is well modeled by the concept of sweeping of an instability. When pressure is increased, the exponent β characterizing the power-law distribution avalanche sizes significantly decreases and the exponent γ characterizing the cutoff divergence when failure is approached significantly increases. This proves that fluid pressure plays a key role in failure process acting as destabilization factor. This indicates that macrofailure occurs more readily under fluid pressure, with a behavior that becomes progressively unstable as fluid pressure increases. This may have considerable consequences on our ability to forecast failure when fluid pressure is acting.

  9. Fiber bundle model under fluid pressure. (United States)

    Amitrano, David; Girard, Lucas


    Internal fluid pressure often plays an important role in the rupture of brittle materials. This is a major concern for many engineering applications and for natural hazards. More specifically, the mechanisms through which fluid pressure, applied at a microscale, can enhance the failure at a macroscale and accelerate damage dynamics leading to failure remains unclear. Here we revisit the fiber bundle model by accounting for the effect of fluid under pressure that contributes to the global load supported by the fiber bundle. Fluid pressure is applied on the broken fibers, following Biot's theory. The statistical properties of damage avalanches and their evolution toward macrofailure are analyzed for a wide range of fluid pressures. The macroscopic strength of the new model appears to be strongly controlled by the action of the fluid, particularly when the fluid pressure becomes comparable with the fiber strength. The behavior remains consistent with continuous transition, i.e., second order, including for large pressure. The main change concerns the damage acceleration toward the failure that is well modeled by the concept of sweeping of an instability. When pressure is increased, the exponent β characterizing the power-law distribution avalanche sizes significantly decreases and the exponent γ characterizing the cutoff divergence when failure is approached significantly increases. This proves that fluid pressure plays a key role in failure process acting as destabilization factor. This indicates that macrofailure occurs more readily under fluid pressure, with a behavior that becomes progressively unstable as fluid pressure increases. This may have considerable consequences on our ability to forecast failure when fluid pressure is acting. PMID:27078437

  10. Prevention and management of pressure ulcers. (United States)

    Thomas, David R


    Pressure ulcers represent complex wounds that are difficult to prevent or manage. Guidelines for prevention include identifying patients at risk, reducing the effect of pressure, friction, shear forces, and assessing co-morbidities such as nutritional status. Management should follow eight treatment strategies including accurately assessing the ulcer, relieving pressure, assessing pain and nutritional status, maintaining a moist wound environment, encouraging granulation and epithelial tissue formation, evaluating the need for debridement, and controlling infection. PMID:17410826

  11. On the abdominal pressure volume relationship


    Mulier, Jan Paul; Dillemans, Bruno; Crombach, Mark; Missant, Carlo; Sels, Annabel


    Abstract: During insufflation of the abdomen to create a pneumoperitoneum for laparoscopy, both intra abdominal pressure and insufflated volume can be measured and are used to calculate the abdominal pressure-volume relationship. First, an accurate, linear relationship was identified using a mathematical model with an elastance, E, or its reciprocal the compliance C and with a pressure at zero volume, PV0. This function was stable and could be used to describe the abdominal characteristics of...

  12. Management of patients with pressure ulcers


    Bora Ozel


    A pressure ulcer is an area of localized damage to the skin and underlying tissue caused by pressure or shear. Although these ulcers can occur anywhere on the body, they are often located in the ischial, trochanteric, sacral areas and. heel. These ulcers are primarily the products of a combination of pressure and decreased angiogenic response. Early intervention and comprehensive treatment should result in complete healing of ulcers. In this review, we tried to create a general perspective ab...

  13. A ferrofluid-based wireless pressure sensor


    Chitnis, Girish; Ziaie, Babak


    This paper presents a wireless pressure sensor design based on magnetic fluid displacement over a planar coil and its corresponding inductance change. The design of the pressure sensor is presented followed by its fabrication and characterization. Experimental results show a good correlation with a nonlinear model relating the applied pressure to the change in coil self-resonant frequency. A prototype sensor (radius = 6 mm, thickness = 2 mm) based on the above principal using an oil-based fer...

  14. Effective Coulomb interactions in solids under pressure


    Tomczak, Jan M.; Miyake, T; Sakuma, R.; Aryasetiawan, F.


    Correlated materials are extremely sensitive to external stimuli, such as temperature or pressure. Describing the electronic properties of such systems often requires applying many-body techniques to effective low energy problems in the spirit of the Hubbard model, or extensions thereof. While the effect of pressure on structures and bands has been investigated extensively within density-functional based methods, the pressure dependence of electron-electron interactions has so far received li...

  15. Negative pressure wound therapy: clinical utility


    Sandoz H


    Heidi Sandoz Accelerate CIC, Mile End Hospital, London, UK Abstract: Negative pressure wound therapy (NPWT), also known as topical negative pressure therapy, has been increasingly used in health care for the management of a wide variety of wounds over the last 2–3 decades. It is an advanced therapy that can be helpful to accelerate wound healing in both acute and chronic wounds by delivering negative pressure (suction) to the wound bed. More recent advancements in the application o...

  16. Biofeedback With Implanted Blood-Pressure Device (United States)

    Rischell, Robert E.


    Additional uses found for equipment described in "Implanted Blood-Pressure-Measuring Device" (GSC-13042). Implanted with device electronic circuitry that measures, interprets, and transmits data via inductive link through patient's skin to external receiver. Receiver includes audible alarm generator activated when patient's blood pressure exceeds predetermined threshold. Also included in receiver a blood-pressure display, recorder, or both, for use by patient or physician.

  17. Blood pressure changes in dogs with babesiosis

    Directory of Open Access Journals (Sweden)

    L.S. Jacobson


    Full Text Available Systemic arterial blood pressures were measured in 30 dogs with acute babesiosis, 10 each with mild uncomplicated, severe uncomplicated and complicated disease. Ten healthy dogs were used as controls. Hypotension was defined as more than 3 standard deviations below the control mean. Normal mean pressures (±SD were: systolic arterial pressure 151 (±11 mm Hg, diastolic arterial pressure 89 (±8 mm Hg and mean arterial pressure 107 (±10 mmHg. Hypotension was the most frequent abnormality, and increased strikingly in incidence as disease severity increased, with 5/10 dogs in the complicated group being hypotensive for systolic, diastolic and mean arterial pressures, compared with 2/10 in the severe uncomplicated group and 0/10 in the mild uncomplicated group. Systolic, diastolic and mean arterial pressures in the complicated group and severe uncomplicated group, and systolic pressure in the mild uncomplicated group, were significantly lower than in the controls. There were no significant relationships between arterial pressures and age, pulse rate, respiratory rate, temperature, mucous membrane colour or haematocrit. There was a significant negative correlation between arterial pressures and white cell and immature neutrophil counts. Arterial pressures differed significantly between dogs that were clinically collapsed and those that were not, but not between survivors and non-survivors. Pulse pressure (systolic - diastolic was low in 7/10 complicated, 1/10 mild uncomplicated, and 1/10 severe uncomplicated cases, and differed significantly between the complicated and control groups. The high incidence of hypotension in clinically severe babesiosis has important implications for therapy.

  18. Home blood pressure monitoring for mild hypertensives.


    Midanik, L T; Resnick, B; Hurley, L B; Smith, E J; Mccarthy, M.


    A clinical trial of 204 untreated patients with mild hypertension was conducted to assess the effect of home blood pressure monitoring on blood pressure level, pharmacologic treatment, reduction of risk factors, and use of health services. After 1 year, no statistically significant differences were found between the treatment and control groups. The findings indicate that, while home blood pressure monitoring may be useful, it has no measurable short-term impact on these aspects of blood pres...

  19. [Ambulatory invasive and noninvasive blood pressure monitoring]. (United States)

    Bachmann, K; Wortmann, A; Engels, G


    Indirect arterial blood pressure measurement has not changed substantially since its introduction by Riva-Rocci in 1986, Korotkoff in 1905 and Recklinghausen in 1906. Random measurements in the clinic or practice reflect only incompletely the dynamic nature of the blood pressure. Blood pressure recordings by patients themselves have provided more information through better temporal resolution, however, exact characterization of the pressure response throughout the entire day and, in particular, during physical exertion are not enabled; the latter are especially important with regard to diagnosis and treatment of hypertension. In 1966, therefore, radiotelemetric transmission of direct, continuously-measured arterial blood pressure was developed which enabled beat-to-beat registration of blood pressure, outside the laboratory, during normal daily life and sport activities. The initial results showed a marked variability of the blood pressure during the course of the day (Figure 1). Excessive blood pressure increases were observed during exposure to cold, static and dynamic exercise and to a lesser degree during automobile driving and exposure to heat (Figure 3). Recording of the pressure curves via transmission by radiotelemetry shows a high degree of accuracy and temporal resolution, spatial and situational freedom but is invasive and costly in terms of personnel. The same holds true for direct continuous blood pressure registration and storage on a portable tape recorder. Portable, automatic blood pressure measuring units for ambulatory monitoring employ indirect auscultatory or oscillometric recording with a cuff. As compared with the radiotelemetric direct continuous blood pressure measuring method, the indirect method has subordinate temporal resolution, that is, the measurements are only intermittent.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2676813

  20. Rotor/Stator Unsteady Pressure Interaction


    Brennen, C. E.; Franz, R.; Arndt, N.


    This paper describes an investigation of rotor/stator interaction in centrifugal pumps with radial diffusers. Steady and unsteady diffuser vane pressure measurements were made for two impellers, one half of the double suction pump of the High Pressure Oxygen Turbopump (HPOTP) of the Space Shuttle Main Engine (SSME) and a two-dimensional impeller. Unsteady impeller blade pressure measurements were made for a second two-dimensional impeller with blade number and geometry identical to the two-di...

  1. Mechanical Buckling of Veins under Internal Pressure


    Martinez, Ricky; Fierro, Cesar A.; Shireman, Paula K.; Han, Hai-Chao


    Venous tortuosity is associated with multiple disease states and is often thought to be a consequence of venous hypertension and chronic venous disease. However, the underlying mechanisms of vein tortuosity are unclear. We hypothesized that increased pressure causes vein buckling that leads to a tortuous appearance. The specific aim of this study was to determine the critical buckling pressure of veins. We determined the buckling pressure of porcine jugular veins and measured the mechanical p...

  2. Studies on pressure suppression pool dynamic loads

    International Nuclear Information System (INIS)

    Several newly identified pressure suppression pool hydrodynamic loads associated with a loss-of-coolant accident, or actuation of the safety/relief valves, are attracting attention because of their potential influence on integrity of the BWR pressure suppression containment. This report provides a survey of the research works and experiences on performance of the pressure suppression system during abnormal and normal reactor operating conditions. Specific areas for future studies are also indicated. (author)

  3. Life style as a blood pressure determinant.


    Staessen, J A; Bieniaszewski, L; Pardaens, K; V. Petrov; Thijs, L.; Fagard, R.


    In Belgium, an affluent Western European country, participation in sports, alcohol intake, and living in a working class area were identified as the life style factors with the closest associations with the blood pressure level. Obesity was another important blood pressure correlate. Sodium intake, determined from the 24 h urinary output, and smoking were not associated with blood pressure. Controlled intervention studies have proven that weight reduction, endurance training and alcohol absti...

  4. 'Peer pressure' in larval Drosophila? (United States)

    Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram


    Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. PMID:24907371

  5. Reactor pressure vessel. Status report

    International Nuclear Information System (INIS)

    This report describes the issues raised as a result of the staffs review of Generic Letter (GL) 92-01, Revision 1, responses and plant-specific reactor pressure vessel (RPV) assessments and the actions taken or work in progress to address these issues. In addition, the report describes actions taken by the staff and the nuclear industry to develop a thermal annealing process for use at U.S. commercial nuclear power plants. This process is intended to be used as a means of mitigating the effects of neutron radiation on the fracture toughness of RPV materials. The Nuclear Regulatory Commission (NRC) issued GL 92-01, Revision 1, Supplement 1, to obtain information needed to assess compliance with regulatory requirements and licensee commitments regarding RPV integrity. GL 92-01, Revision 1, Supplement 1, was issued as a result of generic issues that were raised in the NRC staff's reviews of licensee responses to GL 92-01, Revision 1, and plant-specific RPV evaluations. In particular, an integrated review of all data submitted in response to GL 92-01, Revision 1, indicated that licensees may not have considered all relevant data in their RPV assessments. This report is representative of submittals to and evaluations by the staff as of September 30, 1996. An update of this report will be issued at a later date

  6. Nasal continuous positive airway pressure

    DEFF Research Database (Denmark)

    Scholze, Alexandra; Lamwers, Stephanie; Tepel, Martin; Sanner, Bernd M


    Obstructive sleep apnoea (OSA) is linked to increased cardiovascular risk. This risk can be reduced by nasal continuous positive airway pressure (nCPAP) treatment. As OSA is associated with an increase of several vasoconstrictive factors, we investigated whether nCPAP influences the digital volume...... automated analysis. In patients with OSA and an apnoea/hypopnoea index (AHI) of >10 events · h(-1), a significant vasoconstriction was observed during the night (p<0.0001 by Friedman's test). A significant positive correlation existed between vasoconstriction and AHI (Spearman correlation, r = 0.27; p<0.......01; n = 94) and the arousal index (Spearman correlation, r = 0.21; p < 0.05; n = 94). After 6 months of nCPAP treatment, the AHI was significantly reduced from 27 ± 3 events · h(-1) to 4 ± 2 events · h(-1) (each n = 29; p<0.001) and vasoconstriction during the night was significantly reduced from 10 ± 3...

  7. Thermal ratchetting in pressure vessels

    International Nuclear Information System (INIS)

    During its lifetime a nuclear power plant undergoes cyclic thermal loadings, i.e. time variations of temperature spatial distribution; these thermal cycles combined with methanical loads (pressure), can produce dimensional changes for creep, plastic cycling and/or ratchetting. This problem is in special way important for a Liquid Metal Fast Breeder Reactor (LMFBR) because temperatures in it are high (about 5000C) and change either in radial direction or in axial direction. While the plastic behaviour of a structure subjected to mechanical loads and/or mechanical cycle loads can be well studied by Finite Element analyses and several different computer programs, the thermal plastic behaviour was studied for simplified conditions only. Actually, the Bree, Miller, Burgreen model considers a thin cylindrical shell with a radial thermal gradient and in uniaxial stress state while Kalnins, Updike extend this model to a biaxial stress state. To obtain numerical results of the thermo-plastic behaviour of cylindrical shells, a mathematical model was developed and the special purpose computer program PLAST was implemented. (Auth.)

  8. Osmosis at constant volume. Negative pressure

    CERN Document Server

    Zupanovic, Pasko; Brumen, Milan; Fajmut, Ales; Juretic, Davor


    A thermodynamic state of solvent and solution separated with an elastic semipermeable membrane, in the box with a fixed volume, is considered. It is shown that the minimum of the free energy is accompanied by the compression of the solution and tension of the solvent caused by the transfer of solvent molecules into compartment with solution. The tensile state of the solvent is described in terms of negative pressure. It is found that the negative pressure as well as compression pressure is of the order of osmotic pressure given by van't Hoff equation. It is proposed that this mechanism could be responsible for the water uptake in tall trees.

  9. Dependence of osmotic pressure on solution properties

    International Nuclear Information System (INIS)

    Hydrostatic pressure, temperature, salt concentration, and the chemical composition of the salt are parameters affecting solution properties. Pressure and temperature have little effect on osmosis, but osmotic pressure variations due to type of dissolved salt may be significant, especially at high concentrations. For a given salt solution, concentration variations cause large differences in osmotic pressure. A representative difference in concentration across a clay layer in a relatively shallow groundwater system might be 100 to 1,000 ppm. When expressed as ppm NaCl, this difference could cause a head difference of 0.8 to 8 meters of water if one of the rock bodies were closed to fluid escape

  10. Intelligent pressure measurement in multiple sensor arrays

    International Nuclear Information System (INIS)

    Pressure data acquisition has typically consisted of a group of sensors scanned by an electronic or mechanical multiplexer. The data accuracy was dependent upon the temperature stability of the sensors. This paper describes a new method of pressure measurement that combines individual temperature compensated pressure sensors, a microprocessor, and an A/D converter in one module. Each sensor has its own temperature characteristics stored in a look-up table to minimize sensor thermal errors. The result is an intelligent pressure module that can output temperature compensated engineering units over an Ethernet interface. Calibration intervals can be dramatically extended depending upon system accuracy requirements and calibration techniques used

  11. Vacuum-sealed casting process under pressure

    Institute of Scientific and Technical Information of China (English)

    LI Chen-xi; GUO Tai-ming; WU Chun-jing; WANG Hong


    A new casting method, the vacuum-sealed mold casting under pressure, has been developed, and thin wall iron castings with high precision and smooth surface have been produced successfully with this casting method. The experimental results show that the liquid iron has a very excellent filling ability because a high negative pressure is formed in the mold cavity during filling process. The vacuum-sealed mold under pressure has very high compressive strength greater than 650 kPa, which is 3-4 times as high as that of the molds produced by high-pressure molding process or vacuum-sealed molding process.

  12. High Chamber Pressure, Light Weight Thrusters Project (United States)

    National Aeronautics and Space Administration — The performance liquid propellant engines can be significantly improved by increasing both combustion temperature and pressure and reducing engine weight. State of...

  13. Pressure ulcer prevention in frail older people. (United States)

    Barry, Maree; Nugent, Linda


    Pressure ulcers are painful and cause discomfort, have a negative effect on quality of life, and are costly to treat. The incidence and severity of preventable pressure ulcers is an important indicator of quality of care; it is essential that healthcare providers monitor prevalence and incidence rates to ensure that care strategies implemented are effective. Frail older people are at increased risk of developing pressure ulcers. This article discusses the complexities of preventing pressure ulcers in frail older people and emphasises the importance of structured educational programmes that incorporate effective clinical leadership and multidisciplinary teamwork. PMID:26669407

  14. Ideal bulk pressure of active Brownian particles (United States)

    Speck, Thomas; Jack, Robert L.


    The extent to which active matter might be described by effective equilibrium concepts like temperature and pressure is currently being discussed intensely. Here, we study the simplest model, an ideal gas of noninteracting active Brownian particles. While the mechanical pressure exerted onto confining walls has been linked to correlations between particles' positions and their orientations, we show that these correlations are entirely controlled by boundary effects. We also consider a definition of local pressure, which describes interparticle forces in terms of momentum exchange between different regions of the system. We present three pieces of analytical evidence which indicate that such a local pressure exists, and we show that its bulk value differs from the mechanical pressure exerted on the walls of the system. We attribute this difference to the fact that the local pressure in the bulk does not depend on boundary effects, contrary to the mechanical pressure. We carefully examine these boundary effects using a channel geometry, and we show a virial formula for the pressure correctly predicts the mechanical pressure even in finite channels. However, this result no longer holds in more complex geometries, as exemplified for a channel that includes circular obstacles.

  15. Transient study of a PWR pressurizer

    International Nuclear Information System (INIS)

    An appropriate method for the calculation and transient performance of the pressurizer of a pressurized water reactor is presented. The study shows a digital program of simulation of pressurizer dynamics based on the First Law of Thermodynamic and Laws of Heat and Mass Transfer. The importance of the digital program that was written for a pressurizer of PWR, lies in the fact that, this can be of practical use in the safety analysis of a reactor of Angra dos Reis type with a power of about 500 M We. (author)

  16. Surface pressures from laser-supported detonations

    International Nuclear Information System (INIS)

    The surface pressures directly behind a Laser-Supported Detonation (LSD) were measured with a system of carbon piezoresistive gauges. A quartz piezoelectric gauge was also used to measure surface pressures far away from the laser spot. The small size of the carbon gauges, relative to the laser beam diameter, permitted simultaneous resolution of the surface pressure history at several locations within the laser spot. A comparison of the experimental data with recent theories indicates that the theories predict peak pressures close to those measured but overestimate the impulse intensity at the target surface



    Spain, I.; Hu, J; Menoni, C.; Black, D


    X-ray diffraction experiments have been carried out on Ge, Si, Gap, InAs at ultrahigh pressure in the diamond anvil high pressure apparatus. Three phases of Si (β-Sn, simple hexagonal, hcp) have been found on increase of pressure, with bcc phase on release. Only one phase of Ge (β-Sn) has been found to 25 GPa, with tetragonal phase on release. InAs transforms to NaCl phase at high pressure, with some hysteresis in the transformation back to the original zinc-blend phase. Experiments on Gap in...

  18. Techniques in high pressure neutron scattering

    CERN Document Server

    Klotz, Stefan


    Drawing on the author's practical work from the last 20 years, Techniques in High Pressure Neutron Scattering is one of the first books to gather recent methods that allow neutron scattering well beyond 10 GPa. The author shows how neutron scattering has to be adapted to the pressure range and type of measurement.Suitable for both newcomers and experienced high pressure scientists and engineers, the book describes various solutions spanning two to three orders of magnitude in pressure that have emerged in the past three decades. Many engineering concepts are illustrated through examples of rea

  19. Let's Talk about High Blood Pressure and Stroke (United States)

    ... Tools & Resources Stroke More Let's Talk About High Blood Pressure and Stroke Updated:Dec 9,2015 What is ... Blood Pressure? How Can I Reduce High Blood Pressure? High Blood Pressure and Stroke What Is Diabetes and How ...

  20. Impact of Moisture on the Pressure Delivering Potential of Pressure Garments. (United States)

    Macintyre, Lisa; Dahale, Monali; Rae, Michelle


    Pressure garments are the main method of treatment and prophylaxis for hypertrophic burn scars. The pressure they exert on the scarred skin prevents contractures forming, reduces the itchiness and pruritus associated with active hypertrophic scars, and is believed, by many, to hasten normalization of the scar tissue. The pressure exerted is believed to be critical to treatment success and can be predicted based on laboratory measurement of the fabric's tension profile. All previous research on the pressures delivered by pressure garments has been undertaken using dry fabrics in either laboratory or clinical conditions. However, many patients have complained of increased perspiration when wearing pressure garments, and many burn victims live and work in hot conditions where high levels of perspiration may be expected. This article investigated the impact of moisture content on fabric tension and thus the pressure exerting ability of pressure garments. Four different fabrics currently used in the construction of pressure garments were evaluated in seven different states of "wetness" from completely dry to completely saturated in water or artificial perspiration. Standard laboratory methods were used to measure the initial tension in fabrics and the tension after 11 cycles of extension. Pressures that would be exerted by these fabrics were calculated using the Laplace law. The results of this study showed that the tension, and therefore pressure delivering ability, of fabrics used in pressure garments was significantly reduced when they were wet but that the amount or type of "wetness" did not have a significant effect on pressure delivering ability. PMID:26171677

  1. Pressure distension in leg vessels as influenced by prolonged bed rest and a pressure habituation regimen. (United States)

    Eiken, Ola; Mekjavic, Igor B; Kounalakis, Stylianos N; Kölegård, Roger


    Bed rest increases pressure distension in arteries, arterioles, and veins of the leg. We hypothesized that bed-rest-induced deconditioning of leg vessels is governed by the removal of the local increments in transmural pressure induced by assuming erect posture and, therefore, can be counteracted by intermittently increasing local transmural pressure during the bed rest. Ten men underwent 5 wk of horizontal bed rest. A subatmospheric pressure (-90 mmHg) was intermittently applied to one lower leg [pressure habituation (PH) leg]. Vascular pressure distension was investigated before and after the bed rest, both in the PH and control (CN) leg by increasing local distending pressure, stepwise up to +200 mmHg. Vessel diameter and blood flow were measured in the posterior tibial artery and vessel diameter in the posterior tibial vein. In the CN leg, bed rest led to 5-fold and 2.7-fold increments (P tibial artery pressure-distension and flow responses, respectively, and to a 2-fold increase in tibial vein pressure distension. In the PH leg, arterial pressure-distension and flow responses were unaffected by bed rest, whereas bed rest led to a 1.5-fold increase in venous pressure distension. It thus appears that bed-rest-induced deconditioning of leg arteries, arterioles, and veins is caused by removal of gravity-dependent local pressure loads and may be abolished or alleviated by a local pressure-habituation regimen. PMID:27079693

  2. Application of High Pressure in Food Processing

    Directory of Open Access Journals (Sweden)

    Herceg, Z.


    Full Text Available In high pressure processing, foods are subjected to pressures generally in the range of 100 – 800 (1200 MPa. The processing temperature during pressure treatments can be adjusted from below 0 °C to above 100 °C, with exposure times ranging from a few seconds to 20 minutes and even longer, depending on process conditions. The effects of high pressure are system volume reduction and acceleration of reactions that lead to volume reduction. The main areas of interest regarding high-pressure processing of food include: inactivation of microorganisms, modification of biopolymers, quality retention (especially in terms of flavour and colour, and changes in product functionality. Food components responsible for the nutritive value and sensory properties of food remain unaffected by high pressure. Based on the theoretical background of high-pressure processing and taking into account its advantages and limitations, this paper aims to show its possible application in food processing. The paper gives an outline of the special equipment used in highpressure processing. Typical high pressure equipment in which pressure can be generated either by direct or indirect compression are presented together with three major types of high pressure food processing: the conventional (batch system, semicontinuous and continuous systems. In addition to looking at this technology’s ability to inactivate microorganisms at room temperature, which makes it the ultimate alternative to thermal treatments, this paper also explores its application in dairy, meat, fruit and vegetable processing. Here presented are the effects of high-pressure treatment in milk and dairy processing on the inactivation of microorganisms and the modification of milk protein, which has a major impact on rennet coagulation and curd formation properties of treated milk. The possible application of this treatment in controlling cheese manufacture, ripening and safety is discussed. The opportunities

  3. Pressure ulcer classification: defining early skin damage. (United States)

    Russell, Linda


    This article is the second of a two-part series. The first part (Russell, 2002) looked at various systems and pitfalls of pressure ulcer classification systems. This article focuses on the difficulties of defining early skin damage. Patients' quality of life suffers significantly with a pressure ulcer. The smell of the exudate may be an embarrassment to the patient. The pain and the distress the patient will experience will not easily be forgotten, i.e. the number of dressings required for a deep pressure ulcer, even after the pressure ulcer has healed, will be a memorable intrusion to the patient's daily routine. Early detection of pressure ulcers and timely intervention are essential in the management of patients with pressure ulcers. Controversy exists over the definition of the first three stages of pressure ulcers, but there is consensus on the definition of deep tissue damage. If the pressure ulcer is covered with black necrotic tissue it is difficult to establish depth of the tissue damage. Intact skin can cause problems, as a sacrum may be purple but intact. There is still considerable debate with regard to reactive hyperaemia, as the exact time parameters for persistent erythema to occur are unknown. Little is understood with regard to the exact pathophysiology of reactive hyperaemia and this area requires further investigation. Blistered skin and skin tone also cause confusion in grading of pressure ulcers. The problems associated with classification of pressure ulcers, using colour classification systems, are discussed and the implications for practice are considered. The confusion surrounding early classification of pressure ulcers is discussed and it is hoped that such confusion can be addressed by standardizing training using one national classification system. PMID:12362151

  4. High-Pressure Lightweight Thrusters (United States)

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


    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

  5. 49 CFR 179.15 - Pressure relief devices. (United States)


    ...) of this section, a reclosing pressure relief valve must have a minimum start-to-discharge pressure... equipped with a reclosing pressure relief valve having a start-to-discharge pressure of not less than 14.5.... (3) The vapor tight pressure of a reclosing pressure relief valve must be at least 80 percent of...

  6. Optical zero-differential pressure switch and its evaluation in a multiple pressure measuring system (United States)

    Powell, J. A.


    The design of a clamped-diaphragm pressure switch is described in which diaphragm motion is detected by a simple fiber-optic displacement sensor. The switch was evaluated in a pressure measurement system where it detected the zero crossing of the differential pressure between a static test pressure and a tank pressure that was periodically ramped from near zero to fullscale gage pressure. With a ramping frequency of 1 hertz and a full-scale tank pressure of 69 N/sq cm gage (100 psig), the switch delay was as long as 2 milliseconds. Pressure measurement accuracies were 0.25 to 0.75 percent of full scale. Factors affecting switch performance are also discussed.


    Directory of Open Access Journals (Sweden)



    Full Text Available Anti-terror engineering has increasing demand in construction industry, but basis of design (BOD is normally not clear for designers. Hardening of structures has limitations when design loads are not defined. Sacrificial foam claddings are one of the most efficient methods to protect blast pressure. Aluminum foam can have designed yield strength according to relative density and mitigate the blast pressure below a target transmitted pressure. In this paper, multi-layered aluminum foam panels were proposed to enhance the pressure mitigation by increasing effective range of blast pressure. Through explicit finite element analyses, the performance of blast pressure mitigation by the multi-layered foams was evaluated. Pressure-impulse diagrams for the foam panels were developed from extensive analyses. Combination of low and high strength foams showed better applicability in wider range of blast pressure.

  8. Hydraulic High Pressure Valve Controller Using the In-Situ Pressure Difference (United States)

    Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor); Hall, Jeffery L. (Inventor)


    A hydraulic valve controller that uses an existing pressure differential as some or all of the power source for valve operation. In a high pressure environment, such as downhole in an oil or gas well, the pressure differential between the inside of a pipe and the outside of the pipe may be adequately large to drive a linear slide valve. The valve is operated hydraulically by a piston in a bore. When a higher pressure is applied to one end of the bore and a lower pressure to the other end, the piston moves in response to the pressure differential and drives a valve attached to it. If the pressure differential is too small to drive the piston at a sufficiently high speed, a pump is provided to generate a larger pressure differential to be applied. The apparatus is conveniently constructed using multiport valves, which can be rotary valves.

  9. Automated high pressure cell for pressure jump x-ray diffraction

    International Nuclear Information System (INIS)

    A high pressure cell for small and wide-angle x-ray diffraction measurements of soft condensed matter samples has been developed, incorporating a fully automated pressure generating network. The system allows both static and pressure jump measurements in the range of 0.1-500 MPa. Pressure jumps can be performed as quickly as 5 ms, both with increasing and decreasing pressures. Pressure is generated by a motorized high pressure pump, and the system is controlled remotely via a graphical user interface to allow operation by a broad user base, many of whom may have little previous experience of high pressure technology. Samples are loaded through a dedicated port allowing the x-ray windows to remain in place throughout an experiment; this facilitates accurate subtraction of background scattering. The system has been designed specifically for use at beamline I22 at the Diamond Light Source, United Kingdom, and has been fully integrated with the I22 beamline control systems.

  10. Density and solidification feeding model of vacuum counter-pressure cast aluminum alloy under grade-pressuring conditions


    Qing-song Yan; Huan Yu; Gang Lu


    The density of vacuum counter-pressure cast aluminum alloy samples under grade-pressuring condition was studied. The effect of grade pressure difference and time on the density of aluminum alloys was discussed, and the solidification feeding model under grade-pressuring condition was established. The results indicate the grade-pressured solidification feeding ability of vacuum counter-pressure casting mainly depends on grade pressure difference and time. With the increase of grade pressure di...

  11. Recommended sublimation pressure and enthalpy of benzene

    Czech Academy of Sciences Publication Activity Database

    Růžička, K.; Fulem, Michal; Červinka, C.


    Roč. 68, Jan (2014), s. 40-47. ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : benzene * vapor pressure * heat capacity * ideal-gas thermodynamic properties * sublimation enthalpy * recommended vapor pressure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.679, year: 2014


    Institute of Scientific and Technical Information of China (English)


    The axial pressure in plasma arc is measured under different conditions. The effects of the parameters, such as welding current, plasma gas flow rate, electrode setback and arc length, on the pressure in plasma arc are investigated and quantitative analyzed to explain the relationship between the quality of weld and the matching of parameters in plasma arc welding process.

  13. 40 CFR 796.1950 - Vapor pressure. (United States)


    ... very low vapor pressures and sorbent loadings, adsorption of the chemical on the glass wool separating... of Agricultural and Food Chemistry, 3:664-670 (1969). (3) Spencer, W.F. and Cliath, M.M. “Vapor Density and Apparent Vapor Pressure of Lindane,” Journal of Agricultural and Food Chemistry,...

  14. Palpatory method of measuring diastolic blood pressure

    Directory of Open Access Journals (Sweden)

    Dinesh Sahu


    Conclusion: The palpatory method would be very useful where frequent blood pressure measurement are being done manually like in wards, in busy OPD, patient on treadmill and also whenever stethoscope is not available. The blood pressure can be measured in noisy environment too.





    The objective of this study was to find if there was a relationship between the time when cardiovascular rehabilitation was running in the patients after myocardial infarction and an average daily value of systolic and diastolic blood pressure at 7-day ambulatory blood pressure monitoring.

  16. Brief Introduction to Digital Acupoint Pressure Therapy

    Institute of Scientific and Technical Information of China (English)


    @@ The Concept of Digital Acupoint Pressure Therapy The digital acupoint pressure therapy means that according to different diseases and the illness condition, the physician strikes, presses or taps the acupoints with hands on the patient's body surface to promote the circulation of qi and blood, thus making dysfunctions of certain organs or the affected areas return to normal.

  17. Intraoral Pressure in Ethnic Wind Instruments

    CERN Document Server

    Goss, Clinton F


    High intraoral pressure generated when playing some wind instruments has been linked to a variety of health issues. Prior research has focused on Western classical instruments, but no work has been published on ethnic wind instruments. This study measured intraoral pressure when playing six classes of ethnic wind instruments (N = 149): Native American flutes (n = 71) and smaller samples of ethnic duct flutes, reed instruments, reedpipes, overtone whistles, and overtone flutes. Results are presented in the context of a survey of prior studies, providing a composite view of the intraoral pressure requirements of a broad range of wind instruments. Mean intraoral pressure was 8.37 mBar across all ethnic wind instruments and 5.21 +/- 2.16 mBar for Native American flutes. The range of pressure in Native American flutes closely matches pressure reported in other studies for normal speech, and the maximum intraoral pressure, 20.55 mBar, is below the highest subglottal pressure reported in other studies during singing...

  18. Enhanced Strength via crack friction and Pressure (United States)

    Wiegand, Donald; Ellis, Kevin; Leppard, Claire


    The effect of pressure on the mechanical response of particulate polymer composites is being studied. Between about 0.1 and 7 MPa for one composite the results indicate that slow crack growth is the dominant failure mode. With continuously creasing strain at low pressures the stress initially increases to a maximum, the compressive strength, then decreases indicating work softening and them becomes approximately constant at a plateau value. Both the compressive strength and the plateau stress increases linearly with pressure but the plateau stress increases with a steeper slope such that at higher pressures work softening is not observed. The results are analyzed in terms of shear cracks with friction between the crack surfaces. The model predicts a threshold stress for crack growth which increases linearly with pressure and further predicts that the compressive strength increases linearly with pressure as observed and with the same slope as the threshold stress. These results clearly indicate that the pressure dependence of the compressive strength is due to the pressure dependence of the threshold stress for crack growth. The changes in the plateau region can also be attributed to frictional effects. Supported by AWE Aldermaston.

  19. Development of Zirconium alloys (for pressure tubes)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Kwon, Sang Chul; Choo, Ki Nam; Jung, Chung Hwan; Yim, Kyong Soo; Kim, Sung Soo; Baek, Jong Hyuk; Jeong, Yong Hwan; Kim, Kyong Ho; Cho, Hae Dong [Korea Atomic Energy Research Inst., Daeduk (Korea, Republic of); Hwang, S. K.; Kim, M. H. [Inha Univ., Incheon (Korea, Republic of); Kwon, S. I [Korea Univ., Seoul (Korea, Republic of); Kim, I. S. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)


    The objective of this research is to set up the basic technologies for the evaluation of pressure tube integrity and to develop improved zirconium alloys to prevent pressure tube failures due to DHC and hydride blister caused by excessive creep-down of pressure tubes. The experimental procedure and facilities for characterization of pressure tubes were developed. The basic research related to a better understanding of the in-reactor performances of pressure tubes leads to noticeable findings for the first time : the microstructural effect on corrosion and hydrogen pick-up behavior of Zr-2.5Nb pressure tubes, texture effect on strength and DHC resistance and enhanced recrystallization by Fe in zirconium alloys and etc. Analytical methodology for the assessment of pressure tubes with surface flaws was set up. A joint research is being under way with AECL to determine the fracture toughness of O-8 at the EOL (End of Life) that had been quadruple melted and was taken out of the Wolsung Unit-1 after 10 year operation. In addition, pressure tube with texture controlled is being made along with VNINM in Russia as a joint project between KAERI and Russia. Finally, we succeeded in developing 4 different kinds of zirconium alloys with better corrosion resistance, low hydrogen pickup fraction and higher creep strength. (author). 121 refs., 65 tabs., 260 figs

  20. The prevention and treatment of pressure ulcers. (United States)

    Ho, Chester H; Bogie, Kath


    Pressure ulcers remain a significant secondary complication for many individuals with spinal cord injury (SCI). Technological advances have the potential to affect both the prevention and treatment of pressure ulcers. The focus of this article is hi-tech devices and methodologies. The current state-of-the-art methods are discussed and conceptual approaches are presented. PMID:17543771

  1. Comparing maximum pressures in internal combustion engines (United States)

    Sparrow, Stanwood W; Lee, Stephen M


    Thin metal diaphragms form a satisfactory means for comparing maximum pressures in internal combustion engines. The diaphragm is clamped between two metal washers in a spark plug shell and its thickness is chosen such that, when subjected to explosion pressure, the exposed portion will be sheared from the rim in a short time.

  2. Structural studies of amorphous Se under pressure


    Tanaka, Keiji


    X-ray-diffraction patterns, macroscopic compressibility, and crystallization in amorphous Se subject to pressure have been investigated. The material exhibits pressure-induced structural modifications in the glassy state and a phase transformation to the hexagonal phase at 120±20 kbar. The observations are discussed on the basis of microscopic and thermodynamic models.

  3. High-pressure differential scanning microcalorimeter (United States)

    Senin, A. A.; Dzhavadov, L. N.; Potekhin, S. A.


    A differential scanning microcalorimeter for studying thermotropic conformational transitions of biopolymers at high pressure has been designed. The calorimeter allows taking measurements of partial heat capacity of biopolymer solutions vs. temperature at pressures up to 3000 atm. The principles of operation of the device, methods of its calibration, as well as possible applications are discussed.

  4. High gas pressure effects on yeast. (United States)

    Espinasse, V; Perrier-Cornet, J-M; Marecat, A; Gervais, P


    Dried microorganisms are particularly resistant to high hydrostatic pressure effects. However, exposure to high pressures of nitrogen proved to be effective in inactivating dried yeasts. In this study, we tried to elucidate this mechanism on Saccharomyces cerevisiae. High-pressure treatments were performed using different inert gases at 150 MPa and 25 degrees C with holding time values up to 12 months. The influence of cell hydration was also investigated. For fully hydrated cells, pressurized gases had little specific effect: cell inactivation was mainly due to compression effects. However, dried cells were sensitive to high pressure of gases. In this latter case, two inactivation kinetics were observed. For holding time up to 1 h, the inactivation rate increased to 4 log and was linked to a loss of membrane integrity and the presence of damage on the cell wall. In such case cell inactivation would be due to gas sorption and desorption phenomena which would rupture dried cells during a fast pressure release. Gas sorption would occur in cell lipid phases. For longer holding times, the inactivation rate increased more slightly due to compression effects and/or to a slower gas sorption. Water therefore played a key role in cell sensitivity to fast gas pressure release. Two hypotheses were proposed to explain this phenomenon: the rigidity of vitrified dried cells and the presence of glassy solid phases which would favor intracellular gas expansion. Our results showed that dried microorganisms can be ruptured and inactivated by a fast pressure release with gases. PMID:18814287

  5. Pressure-induced melting of micellar crystal

    DEFF Research Database (Denmark)

    Mortensen, K.; Schwahn, D.; Janssen, S.


    that pressure improves the solvent quality of water, thus resulting in decomposition of the micelles and consequent melting of the micellar crystal. The combined pressure and temperature dependence reveals that in spite of the apparent increase of order on the 100 angstrom length scale upon increasing...

  6. Noise Evaluation Technique Based on Surface Pressure

    DEFF Research Database (Denmark)

    Fischer, Andreas

    In this chapter the relevant theory for the understanding of TE noise modeling is collected. It contains the acoustic formulations of [31] and [57]. Both give a relation for the far field sound pressure in dependence of the frequency wave number spectral density of the pressure on the airfoil...

  7. Ultrasound periodic inspections of reactor pressure vessels

    International Nuclear Information System (INIS)

    Two versions are described of ultrasonic equipment for periodic inspections of reactor pressure vessels. One uses the principle of exchangeable programmators with solid-state logic while the other uses programmable logic with semiconductor memories. The equipment is to be used for inspections of welded joints on the upper part of the V-1 reactor pressure vessel. (L.O.)

  8. Pressurized SOFC systems for stationary applications


    Leucht, Florian; Seidler, Stephanie; Henke, Moritz; Bessler, Wolfgang G.; Kallo, Josef; Friedrich, K. Andreas


    Solid oxide fuel cell (SOFC) systems show very high electrical efficiencies even at small sizes. DLR applies a multidisciplinary and multiscale approach to designing and optimizing pressurized SOFC systems for hybrid power plants. A large Simulink model library was developed featuring balance-of-plant components as well as fuel cell models. Recently a pressurized cell test rig was taken into operation.

  9. Pressure distribution in centrifugal dental casting. (United States)

    Nielsen, J P


    Equations are developed for liquid metal pressure in centrifugal dental casting, given the instantaneous rotational velocity, density, and certain dimensions of the casting machine and casting pattern. A "reference parabola" is introduced making the fluid pressure concept more understandable. A specially designed specimen demonstrates experimentally the reference parabola at freezing. PMID:355283

  10. Recombination times in germanium under high pressure

    International Nuclear Information System (INIS)

    The influence of pressure on a well defined recombination process was studied. The centres were introduced by γirradiation and the lifetime determined by the decay time of photoconductivity. An optical pressure vessel is described which allows for a hydrostatic variation of 3000 bars. The diffusion constant and lifetime measurements are presented and analysed. (V.J.C.)

  11. What is Pressure? Evidence for Social Pressure as a Type of Regulatory Focus


    Darrell A. Worthy; Markman, Arthur B.; Maddox, W. Todd


    Previous research suggests that pressure leads to choking when learning to classify items based on an explicit rule, but leads to excelling when learning to classify based on an implicit strategy. In this paper we relate social pressure to regulatory focus theory. We propose that the effects of pressure on performance arise because pressure induces a prevention focus that interacts with the more local reward structure of the task. To test this hypothesis, we repeat this previous research with...

  12. Ambulatory Blood Pressure Monitoring and Circadian Rhythm of Blood Pressure in Diabetes Mellitus


    Elena Matteucci; Ottavio Giampietro


    Systolic and diastolic blood pressures display a circadian rhythmicity that can be assessed by 24-hour ambulatory blood pressure monitoring and analysed using the cosinor procedure. Altered characteristics to the circadian rhythm of blood pressure, which may result in adverse health outcomes, have been observed in both prediabetes and diabetes. We have investigated the circadian variability of blood pressure in patients with type 1 and type 2 diabetes. Chronobiologically interpreted ambulator...

  13. Evaluation of spatial pressure distribution during ice-structure interaction using pressure indicating film


    Kim Hyunwook; Ulan-Kvitberg Christopher; Daley Claude


    Understanding of ‘spatial’ pressure distribution is required to determine design loads on local structures, such as plating and framing. However, obtaining a practical ‘spatial’ pressure distribution is a hard task due to the sensitivity of the data acquisition frequency and resolution. High-resolution Pessure-Idicating Flm (PIF) was applied to obtain pressure distribution and pressure magnitude using stepped crushing method. Different types of PIF were stacked at each test to creating a pres...

  14. Reduction of System Inherent Pressure Losses at Pressure Compensators of Hydraulic Load Sensing Systems


    Siebert, Jan; Geimer, Marcus [Hrsg.


    In spite of their high technical maturity, load sensing systems (LS) have system-inherent energy losses that are largely due to the operation of parallel actuators with different loads at the same pressure level. Hereby, the pressure compensators of the system are crucial. So far, excessive hydraulic energy has been throttled at these compensators and been discharged as heat via the oil. The research project “Reduction of System Inherent Pressure Losses at Pressure Compensators of Hydraulic L...

  15. Pressure Control for Offshore Managed Pressure Drilling (MPD): Analysis, Design, and Experimental Validation


    Mahdianfar, Hessam


    Deepwater offshore drilling operations are among the most complex activities. For example in regions such as the Gulf of Mexico, wells are drilled in water depths of up to 3 kilometers, drilling depths can exceed 6 kilometers, and geologic formation pressures can exceed 1400 bar. In offshore wells safe drilling and completion operations can be difficult due to narrow margins between pore pressure and fracture pressures. Moreover multiple zones of uncertain pore pressures and fr...

  16. Relationship between Vehicle Manufacturers Recommended Tyre Pressure and Tyre Pressure Used by Vehicle Owners


    Timothy Alhassan; Prince Y. Andoh; Prince Owusu-Ansah; Justice Alex Frimpong


    This paper studies the relationship between the tyre pressures used by drivers and the vehicle manufacturers recommended tyre pressure. First of all, a survey of vehicles on Kwame Nkrumah University of Science and Technology (KNUST) campus was done to ascertain how tyre pressures of these vehicles deviate from the vehicle manufacturers recommended tyre pressures. Then the survey was extended to other four places namely, Kumasi Polytechnic campus, Asafo, Roman Hill and Kejetia bus depots. The ...



    R.Vinodh Rajkumar


    Blood pressure measuring represents a routine investigation in general medicine. Nokolai Korotkoff was only 31 years old when he made a short presentation to the Scientific Meeting of the Military Hospital of the Academy on 5 November 1905 concerning an easy non-invasive method of blood pressure (BP) measurement, entitled ‘Concerning the problems of the methods of blood pressure measurement’. If the pressure in the cuff is relieved, blood starts coming through the compressed arterial segment...

  18. Evaluation and comparison of routes to obtain pressure coefficients from high-pressure capillary rheometry data


    Cardinaels, Ruth; Van Puyvelde, Peter; Moldenaers, Paula


    A capillary rheometer equipped with a pressure chamber is used to measure the pressure-dependent viscosity of polymethylmethacrylate (PMMA), poly-alpha-methylstyrene-co-acrylonitrile (P alpha MSAN), and low-density polyethylene (LDPE). Data analysis schemes are discussed to obtain pressure coefficients at constant shear rate and at constant shear stress. It is shown that the constant shear stress pressure coefficients have the advantage of being shear stress independent for the three polymers...

  19. The pressure dependence of hydrophobic interactions is consistent with the observed pressure denaturation of proteins


    Hummer, Gerhard; Garde, Shekhar; García, Angel E.; Paulaitis, Michael E.; Pratt, Lawrence R.


    Proteins can be denatured by pressures of a few hundred MPa. This finding apparently contradicts the most widely used model of protein stability, where the formation of a hydrophobic core drives protein folding. The pressure denaturation puzzle is resolved by focusing on the pressure-dependent transfer of water into the protein interior, in contrast to the transfer of nonpolar residues into water, the approach commonly taken in models of protein unfolding. Pressure denaturation of proteins ca...

  20. The Iceland–Lofotes pressure difference: different states of the North Atlantic low-pressure zone


    Jahnke-Bornemann, Annika; Brümmer, Burghard


    The extended North Atlantic low-pressure zone exhibits two pressure minima in the long-term winter mean: the primary one west of Iceland and the secondary one near Norwegian Lofotes Islands. Based on the ERA-40 data set and on wintertime monthly sea level pressure (SLP) anomalies at both places, the states of co- and antivariability are investigated. The covariability represents states of a strongly or weakly developed North Atlantic low-pressure zone. The difference between these two states ...