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Sample records for hydraulic head measurements

  1. Integrated hydraulic cooler and return rail in camless cylinder head

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, Craig D [Clawson, MI; Neal, Timothy L [Ortonville, MI; Swain, Jeff L [Flushing, MI; Raimao, Miguel A [Colorado Springs, CO

    2011-12-13

    An engine assembly may include a cylinder head defining an engine coolant reservoir, a pressurized fluid supply, a valve actuation assembly, and a hydraulic fluid reservoir. The valve actuation assembly may be in fluid communication with the pressurized fluid supply and may include a valve member displaceable by a force applied by the pressurized fluid supply. The hydraulic fluid reservoir may be in fluid communication with the valve actuation assembly and in a heat exchange relation to the engine coolant reservoir.

  2. Averaging hydraulic head, pressure head, and gravitational head in subsurface hydrology, and implications for averaged fluxes, and hydraulic conductivity

    Directory of Open Access Journals (Sweden)

    G. H. de Rooij

    2009-07-01

    Full Text Available Current theories for water flow in porous media are valid for scales much smaller than those at which problem of public interest manifest themselves. This provides a drive for upscaled flow equations with their associated upscaled parameters. Upscaling is often achieved through volume averaging, but the solution to the resulting closure problem imposes severe restrictions to the flow conditions that limit the practical applicability. Here, the derivation of a closed expression of the effective hydraulic conductivity is forfeited to circumvent the closure problem. Thus, more limited but practical results can be derived. At the Representative Elementary Volume scale and larger scales, the gravitational potential and fluid pressure are treated as additive potentials. The necessary requirement that the superposition be maintained across scales is combined with conservation of energy during volume integration to establish consistent upscaling equations for the various heads. The power of these upscaling equations is demonstrated by the derivation of upscaled water content-matric head relationships and the resolution of an apparent paradox reported in the literature that is shown to have arisen from a violation of the superposition principle. Applying the upscaling procedure to Darcy's Law leads to the general definition of an upscaled hydraulic conductivity. By examining this definition in detail for porous media with different degrees of heterogeneity, a series of criteria is derived that must be satisfied for Darcy's Law to remain valid at a larger scale.

  3. Experimental Study For Pizometric Head Distribution Under Hydraulic Structures

    Directory of Open Access Journals (Sweden)

    Dr. Najm Obaid Salim Alghazali

    2015-04-01

    Full Text Available Abstract In this research the experimental method by using Hydraulic modeling used to determination the flow net in order to analyses seepage flow through single- layer soil foundation underneath hydraulic structure. as well as steady the consequence of the cut-off inclination angle on exit gradient factor of safety uplift pressure and quantity of seepage by using seepage tank were designed in the laboratory with proper dimensions with two cutoffs . The physical model seepage tank was designed in two downstream cutoff angles which are 90 and 120 and upstream cutoff angles 90 45 120. After steady state flow the flow line is constructed by dye injection in the soil from the upstream side in front view of the seepage tank and the equipotentials line can be constructed by pizometer fixed to measure the total head. From the result It is concluded that using downstream cut-off inclined towards the downstream side with amp1256 equal 120 that given value of redaction 25 is beneficial in increasing the safety factor against the piping phenomenon. using upstream cut-off inclined towards the downstream side with amp1256 equal 45 that given value of redaction 52 is beneficial in decreasing uplift pressure and quantity of seepage.

  4. Vertical groundwater storage properties and changes in confinement determined using hydraulic head response to atmospheric tides

    Science.gov (United States)

    Acworth, R. Ian; Rau, Gabriel C.; Halloran, Landon J. S.; Timms, Wendy A.

    2017-04-01

    Accurate determination of groundwater state of confinement and compressible storage properties at vertical resolution over depth is notoriously difficult. We use the hydraulic head response to atmospheric tides at 2 cpd frequency as a tracer to quantify barometric efficiency (BE) and specific storage (Ss) over depth. Records of synthesized Earth tides, atmospheric pressure, and hydraulic heads measured in nine piezometers completed at depths between 5 and 55 m into unconsolidated smectitic clay and silt, sand and gravel were examined in the frequency domain. The barometric efficiency increased over depth from ˜0.05 in silty clay to ˜0.15 in sands and gravels. BE for silty clay was confirmed by calculating the loading efficiency as 0.95 using rainfall at the surface. Specific storage was calculated using effective rather than total moisture. The differences in phase between atmospheric pressure and hydraulic heads at 2 cpd were ˜180° below 10 m indicating confined conditions despite the low BE. Heads in the sediment above a fine sand and silt layer at 12 m exhibited a time variable phase difference between 0° and 180° indicating varying confinement. Our results illustrate that the atmospheric tide at 2 cpd is a powerful natural tracer for quantifying groundwater state of confinement and compressible storage properties in layered formations from hydraulic heads and atmospheric pressure records without the need for externally induced hydraulic stress. This approach could significantly improve the development of conceptual hydrogeological model used for groundwater resource development and management.

  5. Hydraulic slotting technology to prevent coal and gas outburst during heading excavation

    Energy Technology Data Exchange (ETDEWEB)

    Wei, G.; Guo, Z.; Xie, L.; Xin, X.; Shan, Z. [Henan Polytechnic University, Jiaozuo (China)

    2007-02-15

    The technology of measures to prevent coal and gas outburst was analyzed in serious outburst coal seam under research and experiments in real situations. A new measure, called hydraulic slotting, was described and studied in detail. The characteristic parameters of hydraulic slotting was given in the Jiaozuo mining area and the characteristics of validity, adaptability and security were evaluated. The research results show that slotting heading by high pressure large diameter jet releases not only the stress surrounding the strata but also the gas in coal seam is revealed. The resistance to coal and gas outburst was increased dramatically at once if the area of the slot was big enough. The experimentation succeeded in a 2000 m heading excavation and prevented coal and gas outburst. The heading driving speed was more than doubled. 6 refs., 3 figs., 3 tabs.

  6. Measurement of soil hydraulic conductivity in relation with vegetation

    Science.gov (United States)

    Chen, Xi; Cheng, Qinbo

    2010-05-01

    Hydraulic conductivity is a key parameter which influences hydrological processes of infiltration, surface and subsurface runoff. Vegetation alters surface characteristics (e.g., surface roughness, litter absorption) or subsurface characteristics (e.g. hydraulic conductivity). Field infiltration experiment of a single ring permeameter is widely used for measuring soil hydraulic conductivity. Measurement equipment is a simple single-ring falling head permeameter which consists of a hollow cylinder that is simply inserted into the top soil. An optimization method on the basis of objective of minimum error between the measured and simulated water depths in the single-ring is developed for determination of the soil hydraulic parameters. Using the single ring permeameter, we measured saturated hydraulic conductivities (Ks) of the red loam soil with and without vegetation covers on five hillslopes at Taoyuan Agro-Ecology Experimental Station, Hunan Province of China. For the measurement plots without vegetation roots, Ks value of the soil at 25cm depth is much smaller than that of surface soil (1.52×10-4 vs. 1.10×10-5 m/s). For the measurement plots with vegetation cover, plant roots significantly increase Ks of the lower layer soil but this increase is not significant for the shallow soil. Moreover, influences of vegetation root on Ks depend on vegetation species and ages. Ks value of the Camellia is about three times larger than that of seeding of Camphor (2.62×10-4 vs. 9.82×10-5 m/s). Ks value of the matured Camellia is 2.72×10-4 m/s while Ks value of the young Camellia is only 2.17×10-4 m/s. Key words: single ring permeameter; soil hydraulic conductivity; vegetation

  7. A new zonation algorithm with parameter estimation using hydraulic head and subsidence observations.

    Science.gov (United States)

    Zhang, Meijing; Burbey, Thomas J; Nunes, Vitor Dos Santos; Borggaard, Jeff

    2014-01-01

    Parameter estimation codes such as UCODE_2005 are becoming well-known tools in groundwater modeling investigations. These programs estimate important parameter values such as transmissivity (T) and aquifer storage values (Sa ) from known observations of hydraulic head, flow, or other physical quantities. One drawback inherent in these codes is that the parameter zones must be specified by the user. However, such knowledge is often unknown even if a detailed hydrogeological description is available. To overcome this deficiency, we present a discrete adjoint algorithm for identifying suitable zonations from hydraulic head and subsidence measurements, which are highly sensitive to both elastic (Sske) and inelastic (Sskv) skeletal specific storage coefficients. With the advent of interferometric synthetic aperture radar (InSAR), distributed spatial and temporal subsidence measurements can be obtained. A synthetic conceptual model containing seven transmissivity zones, one aquifer storage zone and three interbed zones for elastic and inelastic storage coefficients were developed to simulate drawdown and subsidence in an aquifer interbedded with clay that exhibits delayed drainage. Simulated delayed land subsidence and groundwater head data are assumed to be the observed measurements, to which the discrete adjoint algorithm is called to create approximate spatial zonations of T, Sske , and Sskv . UCODE-2005 is then used to obtain the final optimal parameter values. Calibration results indicate that the estimated zonations calculated from the discrete adjoint algorithm closely approximate the true parameter zonations. This automation algorithm reduces the bias established by the initial distribution of zones and provides a robust parameter zonation distribution.

  8. Design Formulae for Hydraulic Stability and Structural Integrity of Dolos Breakwater Round-Heads

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Jensen, Jacob Birk; Liu, Z.

    1995-01-01

    A rational design of Dolos armour unit should incorporate both the hydraulic stability and the structural integrity. The previous tests performed by Aalborg University (AU) resulted in design formulae for the trunk of a 1:1.5 slope Dolos breakwater without superstructure including both...... the hydraulic stability and the structural integrity. The objective of the round-head tests is to produce similar design formulae for Dolos armour in around-head. The tests will also include examinations of the hydraulic stability and run-up for a trunk section adjacent to the round-head. A run-up formula...

  9. Measurement and modeling of unsaturated hydraulic conductivity

    Science.gov (United States)

    Perkins, Kim S.; Elango, Lakshmanan

    2011-01-01

    The unsaturated zone plays an extremely important hydrologic role that influences water quality and quantity, ecosystem function and health, the connection between atmospheric and terrestrial processes, nutrient cycling, soil development, and natural hazards such as flooding and landslides. Unsaturated hydraulic conductivity is one of the main properties considered to govern flow; however it is very difficult to measure accurately. Knowledge of the highly nonlinear relationship between unsaturated hydraulic conductivity (K) and volumetric water content is required for widely-used models of water flow and solute transport processes in the unsaturated zone. Measurement of unsaturated hydraulic conductivity of sediments is costly and time consuming, therefore use of models that estimate this property from more easily measured bulk-physical properties is common. In hydrologic studies, calculations based on property-transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values with the use of neural networks has become increasingly common. Hydraulic properties predicted using databases may be adequate in some applications, but not others. This chapter will discuss, by way of examples, various techniques used to measure and model hydraulic conductivity as a function of water content, K. The parameters that describe the K curve obtained by different methods are used directly in Richards’ equation-based numerical models, which have some degree of sensitivity to those parameters. This chapter will explore the complications of using laboratory measured or estimated properties for field scale investigations to shed light on how adequately the processes are represented. Additionally, some more recent concepts for representing unsaturated-zone flow processes will be discussed.

  10. Locations of hydraulic-head observations (HOBS) for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the well locations for hydraulic-head observations used in the calibration of the transient hydrologic model of the Central Valley flow...

  11. Measurement and evaluation of static characteristics of rotary hydraulic motor

    Directory of Open Access Journals (Sweden)

    Hružík Lumír

    2014-03-01

    Full Text Available The paper describes experimental equipment for measurement of static characteristics of rotary hydraulic motor. It is possible to measure flow, pressure, temperature, speed and torque by means of this equipment. It deals with measurement of static characteristics of a gear rotary hydraulic motor. Mineral oil is used as hydraulic liquid in this case. Flow, torque and speed characteristics are evaluated from measured parameters. Measured mechanical-hydraulic, flow and total efficiencies of the rotary hydraulic motor are adduced in the paper. It is possible to diagnose technical conditions of the hydraulic motor (eventually to recommend its exchange from the experimental measurements.

  12. On the Dynamic Measurements of Hydraulic Characteristics

    Science.gov (United States)

    Hasmatuchi, Vlad; Bosioc, Alin; Münch-Alligné, Cécile

    2016-11-01

    The present work introduces the implementation and validation of a faster method to measure experimentally the efficiency characteristics of hydraulic turbomachines at a model scale on a test rig. The case study is represented by a laboratory prototype of an in-line axial microturbine for water supply networks. The 2.65 kW one-stage variable speed turbine, composed by one upstream 5-blade runner followed by one counter-rotating downstream 7-blade runner, has been installed on the HES-SO Valais/Wallis universal test rig dedicated to assess performances of small hydraulic machinery following the IEC standard recommendations. In addition to the existing acquisition/control system of the test rig used to measure the 3D hill-chart of a turbine by classical static point-by-point method, a second digitizer has been added to acquire synchronized dynamic signals of the employed sensors. The optimal acceleration/deceleration ramps of the electrical drives have been previously identified in order to cope with the purpose of a reduced measurement time while avoiding errors and hysteresis on the acquired hydraulic characteristics. Finally, the comparison between the turbine efficiency hill-charts obtained by dynamic and static point-by-point methods shows a very good agreement in terms of precision and repeatability. Moreover, the applied dynamic method reduces significantly (by a factor of up to ten) the time necessary to measure the efficiency characteristics on model testing.

  13. Effect of hydraulic head and slope on water distribution uniformity of the IDE drip irrigation system

    OpenAIRE

    Ella, Victor B.; Reyes, Manuel R.; R. Yoder

    2008-01-01

    Assessment of the effect of topography and operating heads on the emission uniformity distribution in drip irrigation systems is important in water management and could serve as the basis for optimizing water-use efficiency and crop productivity. This study was carried out to evaluate the effect of slope and hydraulic head on the water distribution uniformity of a low-cost drip irrigation system developed by International Development Enterprises (IDE). The drip system was tested for water dis...

  14. The Use of Hydraulic Head and Atmospheric Tritium to Identify Presence of Fractures in Clayey Aquitards: Numerical Analysis

    Science.gov (United States)

    Farah, E. A.; Parker, B. L.; Cherry, J. A.

    2003-12-01

    Surficial clayey aquitards can provide underlying aquifers with strong protection from contamination if vertically connected open fractures are absent. Hence, methods are needed to identify such contaminant pathways. An existing two-dimensional model for steady-state groundwater flow and solute transport (FRACTRAN) was used for cross-sectional simulations to assess the prospects for using field measurements of hydraulic head and atmospheric (i.e. bomb) tritium in surficial aquitards to determine presence and nature of hydraulically connected fractures. Simulations for a 15-m thick horizontal aquitard, with shallow water table and downward groundwater flow, show that field measurements of head and tritium at points appropriately spaced along a horizontal line at the lower part of the aquitard provide unique insight since they offer the highest chance for detecting vertical fractures. Simulations represented sets of predominant vertical and horizontal fractures of uniform aperture (25 æm) and variable length. The simulations focused on fracture-network features assigned based on the literature of field investigations. The horizontal profiles show peaks and troughs for head, and always peaks for tritium concentrations at fracture localities. Use of only head or tritium alone may locate fractures, but may not discover whether each fracture is connected to the ground surface or aquifer top, or both. On the other hand, the coupled patterns of head and tritium can be used to identify fractures more accurately. For example, a head trough and a tritium sharp peak represent a fully penetrating fracture, while a head peak and a rounded-tip tritium peak represent a partially penetrating fracture. Moreover, these two are easily differentiated from an embedded fracture that is represented by a relatively small head trough and a short sharp tritium peak. The method of monitoring along a horizontal line was applied to the conceptual 15-m thick aquitard imitating horizontal

  15. The Comparison of Predicted and Measured Hydraulic Conductivities of Soils having Different Physical Properties

    Science.gov (United States)

    Zengin, Enes; Abiddin Erguler, Zeynal; Karakuş, Hüseyin

    2015-04-01

    Hydraulic conductivity is one of the most important parameter of earth science related studies such as engineering geology, soil physics, agriculture etc. In order to estimate the ability of soils to transport fluid through particles, field and laboratory tests have been performed since last decades of 19th century. Constant and falling head tests are widely used to directly measure hydraulic conductivity values in laboratory conditions for soils having different particle size distributions. The determination of hydraulic conductivity of soils by performing these methods are time consuming processes and also requires undisturbed samples to reflect in-situ natural condition. Considering these limitations, numerous approaches have been proposed to practically estimate hydraulic conductivity of soils by utilizing empirical equations based on simple physical and index properties such as grain size distribution curves related parameters, porosity, void ratio, etc. Many previous studies show that the hydraulic conductivity values calculated by empirical equations deviate more than two order magnitude than the measured hydraulic conductivity values obtained from convenient permeability tests. In order to investigate the main controlling parameters on hydraulic conductivity of soils, a comprehensive research program was carried out on some disturbed and undisturbed soil samples collected from different locations in Turkey. The hydraulic conductivity values of samples were determined as changing between 10-6 and 10-9 m/s by using falling head tests. In addition to these tests, basic soil properties such as natural water content, Atterberg limits, specific gravity and grain size analyses of these samples were also defined to be used as an input parameters of empirical equations for prediction hydraulic conductivity values. In addition, data from previous studies were also used for the aim of this study. The measured hydraulic conductivity values were correlated with all

  16. An Analytical Solution of Hydraulic Head due to an Oscillatory Pumping Test in a Confined, Unconfined or Leaky Aquifer

    Science.gov (United States)

    Huang, C. S.; Yeh, H. D.

    2014-12-01

    This study builds a mathematical model for three-dimensional (3D) transient hydraulic head induced by an oscillatory pumping test in a confined, unconfined or leaky aquifer. The aquifers are of a rectangular shape where the four sides are under the Robin conditions. The 3D flow governing equation with a line sink term representing a vertical well is employed. The sink term has a cosine function for the oscillatory pumping. A general equation describing the head on the top of the three kinds of aquifers is considered. The analytical head solution of the model is derived by the direct Fourier method and the double-integral transform and in terms of a double series with fast convergence. With the aid of the solution, we have found that the vertical component of flow vanishes when Kv d2/(KhD2) > 1 where Kh and Kv are aquifer's hydraulic conductivities, respectively, D is aquifer's thickness, and d is a distance measured from the pumping well. Under the condition, temporal head distributions predicted by the present solution agree with those predicted by solutions developed based on two-dimensional flow by most previous researches.

  17. Hydraulics.

    Science.gov (United States)

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  18. Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2007-08

    Science.gov (United States)

    Fisher, Jason C.; Twining, Brian V.

    2011-01-01

    During 2007 and 2008, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, collected quarterly depth-discrete measurements of fluid pressure and temperature in six boreholes located in the eastern Snake River Plain aquifer of Idaho. Each borehole was instrumented with a multilevel monitoring system consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers. Hydraulic heads (head) and water temperatures in boreholes were monitored at 86 hydraulically-isolated depth intervals located 448.0 to 1,377.6 feet below land surface. The calculation of head is most sensitive to fluid pressure and the altitude of the pressure transducer at each port coupling; it is least sensitive to barometric pressure and water temperature. An analysis of errors associated with the head calculation determined the accuracy of an individual head measurement at +/- 2.3 feet. Many of the sources of measurement error are diminished when considering the differences between two closely-spaced readings of head; therefore, a +/- 0.1 foot measurement accuracy was assumed for vertical head differences (and gradients) calculated between adjacent monitoring zones. Vertical head and temperature profiles were unique to each borehole, and were characteristic of the heterogeneity and anisotropy of the eastern Snake River Plain aquifer. The vertical hydraulic gradients in each borehole remained relatively constant over time with minimum Pearson correlation coefficients between head profiles ranging from 0.72 at borehole USGS 103 to 1.00 at boreholes USGS 133 and MIDDLE 2051. Major inflections in the head profiles almost always coincided with low permeability sediment layers. The presence of a sediment layer, however, was insufficient for identifying the location of a major head change in a borehole. The vertical hydraulic gradients were defined for the major inflections in the head profiles and were as much as 2.2 feet per foot. Head gradients

  19. Microfluidic parallel circuit for measurement of hydraulic resistance.

    Science.gov (United States)

    Choi, Sungyoung; Lee, Myung Gwon; Park, Je-Kyun

    2010-08-31

    We present a microfluidic parallel circuit that directly compares the test channel of an unknown hydraulic resistance with the reference channel with a known resistance, thereby measuring the unknown resistance without any measurement setup, such as standard pressure gauges. Many of microfluidic applications require the precise transport of fluid along a channel network with complex patterns. Therefore, it is important to accurately characterize and measure the hydraulic resistance of each channel segment, and determines whether the device principle works well. However, there is no fluidic device that includes features, such as the ability to diagnose microfluidic problems by measuring the hydraulic resistance of a microfluidic component in microscales. To address the above need, we demonstrate a simple strategy to measure an unknown hydraulic resistance, by characterizing the hydraulic resistance of microchannels with different widths and defining an equivalent linear channel of a microchannel with repeated patterns of a sudden contraction and expansion.

  20. Pinhole test for identifying susceptibility of soils to piping erosion: effect water quality and hydraulic head

    Energy Technology Data Exchange (ETDEWEB)

    Nadal Romero, E.; Verachtert, E.; Poesen, J.

    2009-07-01

    Piping has been observed in both natural and soils, as well as under different types of land uses and vegetation covers. Despite its importance, no standard widely-applied methodology exists to assess susceptibility of soils to piping. This study aims at evaluating the pinhole test for assessing the susceptibility of soils to piping under different conditions. More precisely, the effects of hydraulic head and water quality are being assessed. Topsoil samples (remoulded specimens) with a small range of water contents were taken in Central Belgium (Heverlee) and the susceptibility of these soil samples are investigated under standardized laboratory conditions with a pinhole test device. Three hydraulic heads (50,180 and 380 mm) and two water qualities (tap and distilled water) were used, reflecting dominant field conditions. (Author) 6 refs.

  1. Simultaneous transient operation of a high head hydro power plant and a storage pumping station in the same hydraulic scheme

    Science.gov (United States)

    Bucur, D. M.; Dunca, G.; Cervantes, M. J.; Cǎlinoiu, C.; Isbǎşoiu, E. C.

    2014-03-01

    This paper presents an on-site experimental analysis of a high head hydro power plant and a storage pumping station, in an interconnected complex hydraulic scheme during simultaneous transient operation. The investigated hydropower site has a unique structure as the pumping station discharges the water into the hydropower plant penstock. The operation regimes were chosen for critical scenarios such as sudden load rejections of the turbines as well as start-ups and stops with different combinations of the hydraulic turbines and pumps operation. Several parameters were simultaneously measured such as the pumped water discharge, the pressure at the inlet pump section, at the outlet of the pumps and at the vane house of the hydraulic power plant surge tank. The results showed the dependence of the turbines and the pumps operation. Simultaneous operation of the turbines and the pumps is possible in safe conditions, without endangering the machines or the structures. Furthermore, simultaneous operation of the pumping station together with the hydropower plant increases the overall hydraulic efficiency of the site since shortening the discharge circuit of the pumps.

  2. Spring 1961 hydraulic head in the lower pumped zone of California's Central Valley (from Williamson and others, 1989)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the spring 1961 hydraulic head in the lower pumped zone of California's Central Valley. It was used to initiate the water-level...

  3. Flowing fluid electrical conductivity logging of a deep borehole during and following drilling: estimation of transmissivity, water salinity and hydraulic head of conductive zones

    Science.gov (United States)

    Doughty, Christine; Tsang, Chin-Fu; Rosberg, Jan-Erik; Juhlin, Christopher; Dobson, Patrick F.; Birkholzer, Jens T.

    2016-11-01

    Flowing fluid electrical conductivity (FFEC) logging is a hydrogeologic testing method that is usually conducted in an existing borehole. However, for the 2,500-m deep COSC-1 borehole, drilled at Åre, central Sweden, it was done within the drilling period during a scheduled 1-day break, thus having a negligible impact on the drilling schedule, yet providing important information on depths of hydraulically conductive zones and their transmissivities and salinities. This paper presents a reanalysis of this set of data together with a new FFEC logging data set obtained soon after drilling was completed, also over a period of 1 day, but with a different pumping rate and water-level drawdown. Their joint analysis not only results in better estimates of transmissivity and salinity in the conducting fractures intercepted by the borehole, but also yields the hydraulic head values of these fractures, an important piece of information for the understanding of hydraulic structure of the subsurface. Two additional FFEC logging tests were done about 1 year later, and are used to confirm and refine this analysis. Results show that from 250 to 2,000 m depths, there are seven distinct hydraulically conductive zones with different hydraulic heads and low transmissivity values. For the final test, conducted with a much smaller water-level drawdown, inflow ceased from some of the conductive zones, confirming that their hydraulic heads are below the hydraulic head measured in the wellbore under non-pumped conditions. The challenges accompanying 1-day FFEC logging are summarized, along with lessons learned in addressing them.

  4. Flowing fluid electrical conductivity logging of a deep borehole during and following drilling: estimation of transmissivity, water salinity and hydraulic head of conductive zones

    Science.gov (United States)

    Doughty, Christine; Tsang, Chin-Fu; Rosberg, Jan-Erik; Juhlin, Christopher; Dobson, Patrick F.; Birkholzer, Jens T.

    2017-03-01

    Flowing fluid electrical conductivity (FFEC) logging is a hydrogeologic testing method that is usually conducted in an existing borehole. However, for the 2,500-m deep COSC-1 borehole, drilled at Åre, central Sweden, it was done within the drilling period during a scheduled 1-day break, thus having a negligible impact on the drilling schedule, yet providing important information on depths of hydraulically conductive zones and their transmissivities and salinities. This paper presents a reanalysis of this set of data together with a new FFEC logging data set obtained soon after drilling was completed, also over a period of 1 day, but with a different pumping rate and water-level drawdown. Their joint analysis not only results in better estimates of transmissivity and salinity in the conducting fractures intercepted by the borehole, but also yields the hydraulic head values of these fractures, an important piece of information for the understanding of hydraulic structure of the subsurface. Two additional FFEC logging tests were done about 1 year later, and are used to confirm and refine this analysis. Results show that from 250 to 2,000 m depths, there are seven distinct hydraulically conductive zones with different hydraulic heads and low transmissivity values. For the final test, conducted with a much smaller water-level drawdown, inflow ceased from some of the conductive zones, confirming that their hydraulic heads are below the hydraulic head measured in the wellbore under non-pumped conditions. The challenges accompanying 1-day FFEC logging are summarized, along with lessons learned in addressing them.

  5. INFORMATION-MEASURING TEST SYSTEM OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSIONS

    Directory of Open Access Journals (Sweden)

    I. V. Zhukovytskyy

    2015-08-01

    Full Text Available Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of the diesel locomotive repair enterprises was analyzed. It is achieved based on a detailed review of existing foreign information-measuring test systems for hydraulic transmission of diesel locomotives, BelAZ earthmover, aircraft tug, slag car, truck, BelAZ wheel dozer, some brands of tractors, etc. The problem for creation the information-measuring test systems for diesel locomotive hydraulic transmission is being solved, starting in the first place from the possibility of automation of the existing test stand of diesel locomotives hydraulic transmission at Dnipropetrovsk Diesel Locomotive Repair Plant "Promteplovoz". Methodology. In the work the researchers proposed the method to create a microprocessor automated system of diesel locomotives hydraulic transmission stand testing in the locomotive plant conditions. It acts by justifying the selection of the necessary sensors, as well as the application of the necessary hardware and software for information-measuring systems. Findings. Based on the conducted analysis there was grounded the necessity of improvement the plant hydraulic transmission stand testing by creating a microprocessor testing system, supported by the experience of developing such systems abroad. Further research should be aimed to improve the accuracy and frequency of data collection by adopting the more modern and reliable sensors in tandem with the use of filtering software for electromagnetic and other interference. Originality. The

  6. Joint inversion of hydraulic head and self-potential data associated with harmonic pumping tests

    Science.gov (United States)

    Soueid Ahmed, A.; Jardani, A.; Revil, A.; Dupont, J. P.

    2016-09-01

    Harmonic pumping tests consist in stimulating an aquifer by the means of hydraulic stimulations at some discrete frequencies. The inverse problem consisting in retrieving the hydraulic properties is inherently ill posed and is usually underdetermined when considering the number of well head data available in field conditions. To better constrain this inverse problem, we add self-potential data recorded at the ground surface to the head data. The self-potential method is a passive geophysical method. Its signals are generated by the groundwater flow through an electrokinetic coupling. We showed using a 3-D saturated unconfined synthetic aquifer that the self-potential method significantly improves the results of the harmonic hydraulic tomography. The hydroelectric forward problem is obtained by solving first the Richards equation, describing the groundwater flow, and then using the result in an electrical Poisson equation describing the self-potential problem. The joint inversion problem is solved using a reduction model based on the principal component geostatistical approach. In this method, the large prior covariance matrix is truncated and replaced by its low-rank approximation, allowing thus for notable computational time and storage savings. Three test cases are studied, to assess the validity of our approach. In the first test, we show that when the number of harmonic stimulations is low, combining the harmonic hydraulic and self-potential data does not improve the inversion results. In the second test where enough harmonic stimulations are performed, a significant improvement of the hydraulic parameters is observed. In the last synthetic test, we show that the electrical conductivity field required to invert the self-potential data can be determined with enough accuracy using an electrical resistivity tomography survey using the same electrodes configuration as used for the self-potential investigation.

  7. Measuring Disturbance Impact on Soil Hydraulic Properties

    Science.gov (United States)

    Hinshaw, S.; Mirus, B. B.

    2014-12-01

    Disturbances associated with land cover change such as forest clearing and mono-cropping can have a substantial impact on soil-hydraulic properties, which in turn have a cascading impact on surface and near-surface hydrologic response. Although disturbances and vegetation change can alter soil-water retention and conductivity relations, hydrologic models relying on traditional soil-texture based pedotransfer functions would not be able to capture the disturbance impact on infiltration and soil-moisture storage. Therefore, in-situ estimates of characteristic curves of soil water retention and hydraulic conductivity relations are needed to understand and predict hydrologic impacts of land cover change. We present a method for in-situ estimates of effective characteristic curves that capture hysteretic soil-water retention properties at the plot scale. We apply this method to two different forest treatments and in urban settings to investigate the impact of land-use disturbances on soil-hydraulic properties. We compare our in-situ estimation method to results for simple pedotransfer functions to illustrate how this approach can improve understanding of disturbance impacts on hydrologic processes and function.

  8. Straight-flow hydraulic turbine-generator for ultralow-head

    Energy Technology Data Exchange (ETDEWEB)

    Kushimoto, Masakazu; Ujiie, Ryuichi (Fuji Electric Co., Ltd., Tokyo (Japan))

    1989-01-10

    This report introduces features and structures of the straight-flow hydraulic turbine-generator considered for ultralow-head hydropower generation. Largest feature of straight flow(S/F) is that the generator rotor is fitted so as to surround the periphery of runner. This fundamental structure is classified to overhang type, downstream stay-column type and others dependent on the arrangement of main bearing which supports the rotor weight. The essential part of the hydraulic turbine is the sealing equipment for the center part of the rotor. Special attention must be paid to the selection of material and structure of this equipment. The maximum point to determine the structure is the countermeasure for the radial and axial rigidity reduction in the S/F hydro-generator. It is also necessary to conduct moisture prevention for the generator and to insulate to prevent axial current. 13 refs., 6 figs.

  9. Using environmental tracers and transient hydraulic heads to estimate groundwater recharge and conductivity

    Science.gov (United States)

    Erdal, Daniel; Cirpka, Olaf A.

    2017-04-01

    Regional groundwater flow strongly depends on groundwater recharge and hydraulic conductivity. While conductivity is a spatially variable field, recharge can vary in both space and time. None of the two fields can be reliably observed on larger scales, and their estimation from other sparse data sets is an open topic. Further, common hydraulic-head observations may not suffice to constrain both fields simultaneously. In the current work we use the Ensemble Kalman filter to estimate spatially variable conductivity, spatiotemporally variable recharge and porosity for a synthetic phreatic aquifer. We use transient hydraulic-head and one spatially distributed set of environmental tracer observations to constrain the estimation. As environmental tracers generally reside for a long time in an aquifer, they require long simulation times and carries a long memory that makes them highly unsuitable for use in a sequential framework. Therefore, in this work we use the environmental tracer information to precondition the initial ensemble of recharge and conductivities, before starting the sequential filter. Thereby, we aim at improving the performance of the sequential filter by limiting the range of the recharge to values similar to the long-term annual recharge means and by creating an initial ensemble of conductivities that show similar pattern and values to the true field. The sequential filter is then used to further improve the parameters and to estimate the short term temporal behavior as well as the temporally evolving head field needed for short term predictions within the aquifer. For a virtual reality covering a subsection of the river Neckar it is shown that the use of environmental tracers can improve the performance of the filter. Results using the EnKF with and without this preconditioned initial ensemble are evaluated and discussed.

  10. Impact of uncertainty description on assimilating hydraulic head in the MIKE SHE distributed hydrological model

    DEFF Research Database (Denmark)

    Zhang, Donghua; Madsen, Henrik; Ridler, Marc E.

    2015-01-01

    uncertainty. In most hydrological EnKF applications, an ad hoc model uncertainty is defined with the aim of avoiding a collapse of the filter. The present work provides a systematic assessment of model uncertainty in DA applications based on combinations of forcing, model parameters, and state uncertainties....... This is tested in a case where groundwater hydraulic heads are assimilated into a distributed and integrated catchment-scale model of the Karup catchment in Denmark. A series of synthetic data assimilation experiments are carried out to analyse the impact of different model uncertainty assumptions...

  11. Design of Hydraulic Gauge Head of Differential Pressure Type and Parameter Optimization of the Gauge Head%差压式液压测头的设计及参数优化

    Institute of Scientific and Technical Information of China (English)

    母德强; 崔博; 范以撒; 陈懿

    2014-01-01

    The design and working principle of a hydraulic gauge head is intruced in this paper, which is based on the differential pressure-measuring principle with liquid as working media. With the help of CFX, the differential pres-sure system characteristics curves are plotted and the influence level of the structure parameters on working perfor-mance of the hydraulic gauge head is also analyzed. Bsides, the parameters of the gauge head are optimized.%提出一种以液体为工作介质,基于差压法的液压测头的设计和工作原理。利用CFX软件绘制了Δp-s工作曲线图,分析了各参数对液压测头工作性能的影响,对液压测头的几个重要参数进行了优化。

  12. Measuring lateral saturated soil hydraulic conductivity at different spatial scales

    Science.gov (United States)

    Di Prima, Simone; Marrosu, Roberto; Pirastru, Mario; Niedda, Marcello

    2017-04-01

    substratum of Permian sandstone that exhibits very low drainage, thus preventing deep water percolation (Castellini et al., 2016). In the laboratory, small-scale lateral and vertical saturated hydraulic conductivity, Ks,v, were determined by the constant-head permeameter method (Klute and Dirksen, 1986) on 20 soil cubes of 1331 cm3 of volume (Bagarello and Sgroi, 2008), allowing determination of mean Ks anisotropy for the hillslope. In the field, small-scale Ks,v was determined by infiltration runs of the BEST (Lassabatere et al., 2006) type carried out using a ring with an inner diameter of 0.15 m. The BEST-steady algorithm, proposed by Bagarello et al. (2014), was used to analyze the cumulative infiltration curves in order to decrease the failure rate of the BEST algorithms (Di Prima et al., 2016). The in situ Ks,l at an intermediate spatial scale was estimated by a trench test (Blanco-Canqui et al., 2002) carried out on a monolith 50 cm wide, 68 cm long and 34.5 cm deep (the depth to substratum). Finally, the large spatial scale (hillslope-scale) Ks,lvalue was estimated from the outflow of a 8.5 m large drain and from the perched water table levels monitored in the hillslope, following the methodology of Brooks et al. (2004). Anisotropy was not detected, since the soil cube experiments did not revealed significant differences between Ks,v and Ks,l values. The differences between the Ks datasets measured by the cube and the BEST methods were not statistically significant at p = 0.05. These methods yielded Ks values 6.4 and 5.8 times lower than the hillslope-scale Ks,l, respectively. The Ks,l value obtained by the trench experiment in the soil monolith was 1440 mm h-1, which was only 1.5 times higher than the hillslope-scale Ks,l. Probably, the chosen size of soil monolith was sufficient to properly represent the spatial heterogeneity of the soil in the hillslope. This finding need to be confirmed by further trench tests in soil monoliths to be carried out in the studied

  13. Measurement and modeling of unsaturated hydraulic conductivity: Chapter 21

    Science.gov (United States)

    Perkins, Kim S.; Elango, Lakshmanan

    2011-01-01

    The unsaturated zone plays an extremely important hydrologic role that influences water quality and quantity, ecosystem function and health, the connection between atmospheric and terrestrial processes, nutrient cycling, soil development, and natural hazards such as flooding and landslides. Unsaturated hydraulic conductivity is one of the main properties considered to govern flow; however it is very difficult to measure accurately. Knowledge of the highly nonlinear relationship between unsaturated hydraulic conductivity (K) and volumetric water content () is required for widely-used models of water flow and solute transport processes in the unsaturated zone. Measurement of unsaturated hydraulic conductivity of sediments is costly and time consuming, therefore use of models that estimate this property from more easily measured bulk-physical properties is common. In hydrologic studies, calculations based on property-transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values with the use of neural networks has become increasingly common. Hydraulic properties predicted using databases may be adequate in some applications, but not others.

  14. Numerical analysis of Coriolis effect on low-head hydraulic turbines

    Science.gov (United States)

    Ahn, S. H.; Xiao, Y. X.; Zhou, X. Z.; Zhang, J.; Zeng, C. J.; Luo, Y. Y.; Xu, W.; Wang, Z. W.

    2016-11-01

    For the low-head hydropower station, the operating head is low, and the turbine intake channel is relatively short. The turbine internal flow behaviour can be influenced by fluid flows in the upstream reservoir easily, then it would influence the turbine hydraulic performance. Water flows in the upstream reservoir can be influenced by the Coriolis force by the Earth rotation, and it differs at the different Rossby number. In this paper, the Coriolis effect on the approach flows and the turbine performances are investigated numerically for the low-head units. Firstly, the Coriolis effect (under the different latitudes and the same characteristic length scale) on reservoir flows was predicted. Secondly, the prototype performance of a bulb-type turbine was simulated including the reservoir flow with the Coriolis effect, and then the effect on the turbine performance is be discussed. Results show that the flow field in the upstream reservoir at the low Rossby number, the ratio of inertial force to Coriolis force, can sufficiently influence the turbine intake flows and the turbine performances. Adjusting the side-wall distance can reduce the Coriolis effects.

  15. Effect of hydraulic head and slope on water distribution uniformity of a low-cost drip irrigation system

    OpenAIRE

    Ella, Victor B.; Reyes, Manuel R.; R. Yoder

    2008-01-01

    Metadata only record Assessment of the effect of topography and operating heads on the emission uniformity distribution in drip irrigation systems is important in irrigation water management and could serve as basis for optimizing water use efficiency and crop productivity. This study was carried out to evaluate the effect of hydraulic head and slope on the water distribution uniformity of a low-cost drip irrigation system developed by the International Development Enterprises (IDE), a non...

  16. MEASUREMENT OF HYDRAULIC CONDUCTIVITY DISTRIBUTIONS: A MANUAL OF PRACTICE

    Science.gov (United States)

    The ability of hydrologists to perform field measurements of aquifer hydraulic properties must be enhanced in order to significantly improve the capacity to solve groundwater contamination problems at Superfund and other sites. The primary purpose of this manual is to provide ne...

  17. Evaluation of two methods for measuring saturated hydraulic conductivity of soils under two vegetation covers

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, C.M.; Josa, R.; Poyatos, R.; Llorens, P.; Gallart, F.; Latron, J.; Ferrer, F.

    2009-07-01

    The main goal of this work is to determine and to evaluate the saturated hydraulic conductivity for a silt loam soil in field and laboratory conditions. the experimental area was located in the Vallcebre research catchment, in headwaters of the Llobregat River (NE Spain). Hydraulic conductivity was measured in the field using the Guelph permeameter and field saturated hydraulic conductivity (K{sub f}s) based on Elrick equation was calculated. The Guelph permeameter measures were made in two conditions (dry and wet) and in profiles below two vegetation covers (meadows and forest). To determine the saturated hydraulic conductivity at the laboratory (K{sub s}) the constant head permeameter was used. The average K{sub f}s values for the wet period was about 2 cm.h{sup -}1. During the dry period, both soil profiles presented higher values, about 7.5 cm.h{sup -}1. Under laboratory conditions, means observed K{sub s} values were between 12 and 25 cm.h{sup -}1. The relationship K{sub f}s/k{sub s} was of 0.1 cm.h{sup -}1 in wet conditions and about 0.4 cm.h{sup -}1 in dry conditions. The results indicated significant differences between both methods and between both seasons. differences can be explained by the anisotropy of soils as a consequence of vegetation root system that promotes preferential flows paths. (Author) 10 refs.

  18. Temporal and vertical variation of hydraulic head in aquifers in the Edgewood area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Donnelly, Colleen A.; Tenbus, Fredrick J.

    1998-01-01

    Water-level data and interpretations from previous hydrogeological studies conducted by the U.S. Geological Survey in the Edgewood Area of Aberdeen Proving Ground (APG), Maryland, were compared to determine similarities and differences among the aquifers. Because the sediments that comprise the shallow aquifers are discontinuous, the shallow ground-water-flow systems are local rather than extensive across the Edgewood Area. Hydrogeologic cross sections, hydrographs of water levels, and vertical gradients calculated from previous studies in the Canal Creek area, Graces Quarters, the O-Field area, Carroll Island, and the J-Field area, over periods of record ranging from 1 to 10 years during 1986-97, were used to determine recharge and discharge areas, connections between aquifers, and hydrologic responses of aquifers to natural and anthropogenic stress. Each of the aquifers in the study areas exhibited variation of hydraulic head that was attributed to seasonal changes in recharge. Upward hydraulic gradients and seasonal reversals of vertical hydraulic gradients between aquifers indicate the potential for local ground-water discharge from most of the aquifers that were studied in the Edgewood Area. Hydraulic head in individual aquifers in Graces Quarters and Carroll Island responded to offsite pumping during part of the period of record. Hydraulic head in most of the confined aquifers responded to tidal loading effects from nearby estuaries.

  19. The Maintenance of Heading Machine Hydraulic System%掘进机液压系统的维护

    Institute of Scientific and Technical Information of China (English)

    卞丽霞

    2011-01-01

    The paper mainly discussed the rotation of hydraulic tank, oil return filter system and the axial piston pump of heading machine's hydraulic system, the adjustment of axial piston pump, relief valve pressure and one-way throttle valve and the maintenance of hydraulic system and the using of hydraulic components.%本文主要阐述了掘进机液压系统的液压油箱、液压系统的回油过滤器、轴向柱塞泵的旋转、轴向柱塞泵、溢流阀压力的调整、单向节流阀的调整、液压系统维护、液压元件的使用等维护.

  20. Measurement of Fracture Geometry for Accurate Computation of Hydraulic Conductivity

    Science.gov (United States)

    Chae, B.; Ichikawa, Y.; Kim, Y.

    2003-12-01

    Fluid flow in rock mass is controlled by geometry of fractures which is mainly characterized by roughness, aperture and orientation. Fracture roughness and aperture was observed by a new confocal laser scanning microscope (CLSM; Olympus OLS1100). The wavelength of laser is 488nm, and the laser scanning is managed by a light polarization method using two galvano-meter scanner mirrors. The system improves resolution in the light axis (namely z) direction because of the confocal optics. The sampling is managed in a spacing 2.5 μ m along x and y directions. The highest measurement resolution of z direction is 0.05 μ m, which is the more accurate than other methods. For the roughness measurements, core specimens of coarse and fine grained granites were provided. Measurements were performed along three scan lines on each fracture surface. The measured data were represented as 2-D and 3-D digital images showing detailed features of roughness. Spectral analyses by the fast Fourier transform (FFT) were performed to characterize on the roughness data quantitatively and to identify influential frequency of roughness. The FFT results showed that components of low frequencies were dominant in the fracture roughness. This study also verifies that spectral analysis is a good approach to understand complicate characteristics of fracture roughness. For the aperture measurements, digital images of the aperture were acquired under applying five stages of uniaxial normal stresses. This method can characterize the response of aperture directly using the same specimen. Results of measurements show that reduction values of aperture are different at each part due to rough geometry of fracture walls. Laboratory permeability tests were also conducted to evaluate changes of hydraulic conductivities related to aperture variation due to different stress levels. The results showed non-uniform reduction of hydraulic conductivity under increase of the normal stress and different values of

  1. Applicability of hydraulic dynamometer for measuring load mass on forwarders

    Directory of Open Access Journals (Sweden)

    Pandur Zdravko

    2015-01-01

    Full Text Available In the last few years, with the start of wood biomass production from wood residues, the need for determining the quantity of extracted wood residuals on a landing site has appeared. The beginning of intensive usage of wood residues for wood biomass starts in lowland forest where all wood residues are extracted with forwarders. There are several ways to determine load mass on a forwarder, first and probably most accurate is the use of load cells which are installed between forwarder undercarriage and loading space. In Croatia, as far as it is known, there is no forwarder with such equipment, although manufacturers offer the installation of such equipment when buying a new forwarder. The second option is using a portable measuring platform (axle scale which was already used for research of axle loads of trucks and forwarders. The data obtained with the measuring platform are very accurate, while its deficiency is relatively great mass, large dimensions and high price. The third option is determining mass by using hydraulic dynamometer which is installed on crane between the rotator and the telescopic boom. The production and installation of such a system is very simple, and with the price it can easily compete with previously described measuring systems. The main deficiency of this system is its unsatisfying accuracy. The results of assortment mass measuring with hydraulic dynamometer installed on a hydraulic crane and discussion on factors influencing obtained results will be presented in this paper.

  2. Transient flow between aquifers and surface water: analytically derived field-scale hydraulic heads and fluxes

    Directory of Open Access Journals (Sweden)

    G. H. de Rooij

    2012-03-01

    Full Text Available The increasing importance of catchment-scale and basin-scale models of the hydrological cycle makes it desirable to have a simple, yet physically realistic model for lateral subsurface water flow. As a first building block towards such a model, analytical solutions are presented for horizontal groundwater flow to surface waters held at prescribed water levels for aquifers with parallel and radial flow. The solutions are valid for a wide array of initial and boundary conditions and additions or withdrawals of water, and can handle discharge into as well as lateral infiltration from the surface water. Expressions for the average hydraulic head, the flux to or from the surface water, and the aquifer-scale hydraulic conductivity are developed to provide output at the scale of the modelled system rather than just point-scale values. The upscaled conductivity is time-variant. It does not depend on the magnitude of the flux but is determined by medium properties as well as the external forcings that drive the flow. For the systems studied, with lateral travel distances not exceeding 10 m, the circular aquifers respond very differently from the infinite-strip aquifers. The modelled fluxes are sensitive to the magnitude of the storage coefficient. For phreatic aquifers a value of 0.2 is argued to be representative, but considerable variations are likely. The effect of varying distributions over the day of recharge damps out rapidly; a soil water model that can provide accurate daily totals is preferable over a less accurate model hat correctly estimates the timing of recharge peaks.

  3. A Hydraulic Stress Measurement System for Deep Borehole Investigations

    Science.gov (United States)

    Ask, Maria; Ask, Daniel; Cornet, Francois; Nilsson, Tommy

    2017-04-01

    Luleå University of Technology (LTU) is developing and building a wire-line system for hydraulic rock stress measurements, with funding from the Swedish Research Council and Luleå University of Technology. In this project, LTU is collaborating with University of Strasbourg and Geosigma AB. The stress state influences drilling and drillability, as well as rock mass stability and permeability. Therefore, knowledge about the state of in-situ stress (stress magnitudes, and orientations) and its spatial variation with depth is essential for many underground rock engineering projects, for example for underground storage of hazardous material (e.g. nuclear waste, carbon dioxide), deep geothermal exploration, and underground infrastructure (e.g. tunneling, hydropower dams). The system is designed to conduct hydraulic stress testing in slim boreholes. There are three types of test methods: (1) hydraulic fracturing, (2) sleeve fracturing and (3) hydraulic testing of pre-existing fractures. These are robust methods for determining in situ stresses from boreholes. Integration of the three methods allows determination of the three-dimensional stress tensor and its spatial variation with depth in a scientific unambiguously way. The stress system is composed of a downhole and a surface unit. The downhole unit consists of hydraulic fracturing equipment (straddle packers and downhole imaging tool) and their associated data acquisition systems. The testing system is state of the art in several aspects including: (1) Large depth range (3 km), (2) Ability to test three borehole dimensions (N=76 mm, H=96 mm, and P=122 mm), (3) Resistivity imager maps the orientation of tested fracture; (4) Highly stiff and resistive to corrosion downhole testing equipment; and (5) Very detailed control on the injection flow rate and cumulative volume is obtained by a hydraulic injection pump with variable piston rate, and a highly sensitive flow-meter. At EGU General Assembly 2017, we would like to

  4. Measurement of residual CO2 saturation at a geological storage site using hydraulic tests

    Science.gov (United States)

    Rötting, T. S.; Martinez-Landa, L.; Carrera, J.; Russian, A.; Dentz, M.; Cubillo, B.

    2012-12-01

    Estimating long term capillary trapping of CO2 in aquifers remains a key challenge for CO2 storage. Zhang et al. (2011) proposed a combination of thermal, tracer, and hydraulic experiments to estimate the amount of CO2 trapped in the formation after a CO2 push and pull test. Of these three types of experiments, hydraulic tests are the simplest to perform and possibly the most informative. However, their potential has not yet been fully exploited. Here, a methodology is presented to interpret these tests and analyze which parameters can be estimated. Numerical and analytical solutions are used to simulate a continuous injection in a porous medium where residual CO2 has caused a reduction in hydraulic conductivity and an increase in storativity over a finite thickness (a few meters) skin around the injection well. The model results are interpreted using conventional pressure build-up and diagnostic plots (a plot of the drawdown s and the logarithmic derivative d s / d ln t of the drawdown as a function of time). The methodology is applied using the hydraulic parameters estimated for the Hontomin site (Northern Spain) where a Technology Demonstration Plant (TDP) for geological CO2 storage is planned to be set up. The reduction of hydraulic conductivity causes an increase in observed drawdowns, the increased storativity in the CO2 zone causes a delay in the drawdown curve with respect to the reference curve measured before CO2 injection. The duration (characteristic time) of these effects can be used to estimate the radius of the CO2 zone. The effects of reduced permeability and increased storativity are well separated from wellbore storage and natural formation responses, even if the CO2-brine interface is inclined (i.e. the CO2 forms a cone around the well). We find that both skin hydraulic conductivity and storativity (and thus residual CO2 saturation) can be obtained from the water injection test provided that water flow rate is carefully controlled and head build

  5. Impact of uncertainty description on assimilating hydraulic head in the MIKE SHE distributed hydrological model

    Science.gov (United States)

    Zhang, Donghua; Madsen, Henrik; Ridler, Marc E.; Refsgaard, Jens C.; Jensen, Karsten H.

    2015-12-01

    The ensemble Kalman filter (EnKF) is a popular data assimilation (DA) technique that has been extensively used in environmental sciences for combining complementary information from model predictions and observations. One of the major challenges in EnKF applications is the description of model uncertainty. In most hydrological EnKF applications, an ad hoc model uncertainty is defined with the aim of avoiding a collapse of the filter. The present work provides a systematic assessment of model uncertainty in DA applications based on combinations of forcing, model parameters, and state uncertainties. This is tested in a case where groundwater hydraulic heads are assimilated into a distributed and integrated catchment-scale model of the Karup catchment in Denmark. A series of synthetic data assimilation experiments are carried out to analyse the impact of different model uncertainty assumptions on the feasibility and efficiency of the assimilation. The synthetic data used in the assimilation study makes it possible to diagnose model uncertainty assumptions statistically. Besides the model uncertainty, other factors such as observation error, observation locations, and ensemble size are also analysed with respect to performance and sensitivity. Results show that inappropriate definition of model uncertainty can greatly degrade the assimilation performance, and an appropriate combination of different model uncertainty sources is advised.

  6. Temporal response of hydraulic head, temperature, and chloride concentrations to sea-level changes, Floridan aquifer system, USA

    Science.gov (United States)

    Hughes, J. D.; Vacher, H. L.; Sanford, Ward E.

    2009-06-01

    Three-dimensional density-dependent flow and transport modeling of the Floridan aquifer system, USA shows that current chloride concentrations are not in equilibrium with current sea level and, second, that the geometric configuration of the aquifer has a significant effect on system responses. The modeling shows that hydraulic head equilibrates first, followed by temperatures, and then by chloride concentrations. The model was constructed using a modified version of SUTRA capable of simulating multi-species heat and solute transport, and was compared to pre-development conditions using hydraulic heads, chloride concentrations, and temperatures from 315 observation wells. Three hypothetical, sinusoidal sea-level changes occurring over 100,000 years were used to evaluate how the simulated aquifer responds to sea-level changes. Model results show that hydraulic head responses lag behind sea-level changes only where the Miocene Hawthorn confining unit is thick and represents a significant restriction to flow. Temperatures equilibrate quickly except where the Hawthorn confining unit is thick and the duration of the sea-level event is long (exceeding 30,000 years). Response times for chloride concentrations to equilibrate are shortest near the coastline and where the aquifer is unconfined; in contrast, chloride concentrations do not change significantly over the 100,000-year simulation period where the Hawthorn confining unit is thick.

  7. Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2009–10

    Science.gov (United States)

    Twining, Brian V.; Fisher, Jason C.

    2012-01-01

    During 2009 and 2010, the U.S. Geological Survey’s Idaho National Laboratory Project Office, in cooperation with the U.S. Department of Energy, collected quarterly, depth-discrete measurements of fluid pressure and temperature in nine boreholes located in the eastern Snake River Plain aquifer. Each borehole was instrumented with a multilevel monitoring system consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers. Multilevel monitoring at the Idaho National Laboratory has been ongoing since 2006. This report summarizes data collected from three multilevel monitoring wells installed during 2009 and 2010 and presents updates to six multilevel monitoring wells. Hydraulic heads (heads) and groundwater temperatures were monitored from 9 multilevel monitoring wells, including 120 hydraulically isolated depth intervals from 448.0 to 1,377.6 feet below land surface. Quarterly head and temperature profiles reveal unique patterns for vertical examination of the aquifer’s complex basalt and sediment stratigraphy, proximity to aquifer recharge and discharge, and groundwater flow. These features contribute to some of the localized variability even though the general profile shape remained consistent over the period of record. Major inflections in the head profiles almost always coincided with low-permeability sediment layers and occasionally thick sequences of dense basalt. However, the presence of a sediment layer or dense basalt layer was insufficient for identifying the location of a major head change within a borehole without knowing the true areal extent and relative transmissivity of the lithologic unit. Temperature profiles for boreholes completed within the Big Lost Trough indicate linear conductive trends; whereas, temperature profiles for boreholes completed within the axial volcanic high indicate mostly convective heat transfer resulting from the vertical movement of groundwater. Additionally, temperature profiles

  8. Locations, values, and uncertainties of hydraulic-head observations for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of hydraulic-head observations used in the calibration of the transient model of...

  9. Data tables of well locations, perforated intervals, and time series of hydraulic-head observations for the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the well locations, perforated intervals, and time series of hydraulic-head observations used in the calibration of the transient...

  10. Initial hydraulic heads for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the hydraulic-head values in 16 model layers used to initiate the transient simulation of the Death Valley regional ground-water flow...

  11. Locations, values, and uncertainties of hydraulic-head observations for the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of hydraulic-head observations used in the calibration of the transient model of...

  12. Quantitative measures for assessment of the hydraulic excavator digging efficiency

    Institute of Scientific and Technical Information of China (English)

    Dragoslav JANOSEVIC; Rosen MITREV; Boban ANDJELKOVIC; Plamen PETROV

    2012-01-01

    In this paper,quantitative measures for the assessment of the hydraulic excavator digging efficiency are proposed and developed.The following factors are considered: (a) boundary digging forces allowed for by the stability of an excavator,(b) boundary digging forces enabled by the driving mechanisms of the excavator,(c) factors taking into consideration the digging position in the working range of an excavator,and (d) sign and direction of potential digging resistive force.A corrected digging force is defined and a mathematical model of kinematic chain and drive mechanisms of a five-member excavator configuration was developed comprising: an undercarriage,a rotational platform and an attachment with boom,stick,and bucket.On the basis of the mathematical model of the excavator,software was developed for computation and detailed analysis of the digging forces in the entire workspace of the excavator.By using the developed software,the analysis of boundary digging forces is conducted and the corrected digging force is determined for two models of hydraulic excavators of the same mass (around 17000 kg) with identical kinematic chain parameters but with different parameters of manipulator driving mechanisms.The results of the analysis show that the proposed set of quantitative measures can be used for assessment of the digging efficiency of existing excavator models and to serve as an optimization criterion in the synthesis of manipulator driving mechanisms of new excavator models.

  13. Validation of NIS 500 MPa hydraulic pressure measurement

    Directory of Open Access Journals (Sweden)

    Eltawil Alaaeldin A.

    2017-01-01

    Full Text Available 500 MPa pressure is considered as the common maximum pressure in most of the National Metrology Institutes worldwide; however, validation of the uncertainty in that range required a lot of work. NIS when recognized on, 2008 guaranteed big uncertainty value above 200 MPa due to the absence of international comparison at that time. This paper summarizes the results of a validation of 500 MPa range of hydraulic gauge pressure measurements carried out at NIS. The study covers the calibration through direct comparison and through using of a pressure sensor. The paper summarized the technical work carried out at the results of measurements and the effect of these results on NIS Calibration Measurements Capability. The validation also includes the comparison between the obtained results and pervious calibration of the same piston-cylinder assembly that calibrated against the NIST primary standard.

  14. Comparison of instream methods for measuring hydraulic conductivity in sandy streambeds.

    Science.gov (United States)

    Landon, M K; Rus, D L; Harvey, F E

    2001-01-01

    Streambed hydraulic conductivity (K) values were determined at seven stream transects in the Platte River Basin in Nebraska using different instream measurement techniques. Values were compared to determine the most appropriate technique(s) for use in sandy streambeds. Values of K determined from field falling- and constant-head permeameter tests analyzed using the Darcy equation decreased as permeameter diameter increased. Seepage meters coupled with hydraulic gradient measurements failed to yield K values in 40% of the trials. Consequently, Darcy permeameter and seepage meter tests were not preferred approaches. In the upper 0.25 m of the streambed, field falling- and constant-head permeameter tests analyzed with the Hvorslev solution generally had similar K values that were significantly greater than those determined using the Hazen grain-size, Bouwer and Rice slug test for anisotropic and isotropic conditions, and Alyamani and Sen grain-size methods; median differences between these tests and the Hvorslev falling-head 60 cm diameter permeameter were about 8, 9, 17, and 35 m/day, respectively. The Hvorslev falling-head permeameter test is considered the most robust method for measuring K of the upper 0.25 m of the streambed because of the inherent limitations of the empirical grain-size methods and less sediment disturbance for permeameter than slug tests. However, lateral variability in K along transects on the Platte, North Platte, and Wood Rivers was greater than variability in K between valid permeameter, grain-size, or slug tests, indicating that the method used may matter less than making enough measurements to characterize spatial variability adequately. At the Platte River tributary sites, the upper 0.3 m of the streambed typically had greater K than sediment located 0.3 to 2.5 m below the streambed surface, indicating that deposits below the streambed may limit ground water/surface water fluxes. The Hvorslev permeameter tests are not a practical

  15. Task committee on experimental uncertainty and measurement errors in hydraulic engineering: An update

    Science.gov (United States)

    Wahlin, B.; Wahl, T.; Gonzalez-Castro, J. A.; Fulford, J.; Robeson, M.

    2005-01-01

    As part of their long range goals for disseminating information on measurement techniques, instrumentation, and experimentation in the field of hydraulics, the Technical Committee on Hydraulic Measurements and Experimentation formed the Task Committee on Experimental Uncertainty and Measurement Errors in Hydraulic Engineering in January 2003. The overall mission of this Task Committee is to provide information and guidance on the current practices used for describing and quantifying measurement errors and experimental uncertainty in hydraulic engineering and experimental hydraulics. The final goal of the Task Committee on Experimental Uncertainty and Measurement Errors in Hydraulic Engineering is to produce a report on the subject that will cover: (1) sources of error in hydraulic measurements, (2) types of experimental uncertainty, (3) procedures for quantifying error and uncertainty, and (4) special practical applications that range from uncertainty analysis for planning an experiment to estimating uncertainty in flow monitoring at gaging sites and hydraulic structures. Currently, the Task Committee has adopted the first order variance estimation method outlined by Coleman and Steele as the basic methodology to follow when assessing the uncertainty in hydraulic measurements. In addition, the Task Committee has begun to develop its report on uncertainty in hydraulic engineering. This paper is intended as an update on the Task Committee's overall progress. Copyright ASCE 2005.

  16. Strain gauge measurement uncertainties on hydraulic turbine runner blade

    Science.gov (United States)

    Arpin-Pont, J.; Gagnon, M.; Tahan, S. A.; Coutu, A.; Thibault, D.

    2012-11-01

    Strains experimentally measured with strain gauges can differ from those evaluated using the Finite Element (FE) method. This difference is due mainly to the assumptions and uncertainties inherent to each method. To circumvent this difficulty, we developed a numerical method based on Monte Carlo simulations to evaluate measurement uncertainties produced by the behaviour of a unidirectional welded gauge, its position uncertainty and its integration effect. This numerical method uses the displacement fields of the studied part evaluated by an FE analysis. The paper presents a study case using in situ data measured on a hydraulic turbine runner. The FE analysis of the turbine runner blade was computed, and our numerical method used to evaluate uncertainties on strains measured at five locations with welded strain gauges. Then, measured strains and their uncertainty ranges are compared to the estimated strains. The uncertainty ranges obtained extended from 74 μepsilon to 165 μepsilon. Furthermore, the biases observed between the median of the uncertainty ranges and the FE strains varied from -36 to 36 μepsilon. Note that strain gauge measurement uncertainties depend mainly on displacement fields and gauge geometry.

  17. Observations, measurements and best practices for monitoring hydraulic redistribution

    Science.gov (United States)

    Davis, T. W.; Liang, X.

    2011-12-01

    Hydraulic redistribution (HR) is a biogeophysical phenomenon where plant roots move water through the soil column from areas of high soil moisture content to areas of low soil moisture content. The impacts of this process on the hydrologic cycle at the regional scale are beginning to be studied through the use of numerical modeling. The extent of plant species which exhibit HR, the magnitude of water redistributed and the conditions under which it occurs are still unknown. Therefore models must rely on some general assumptions to account for this process. More information is needed to understand how to correctly account for HR in land surface models. The ideal method is through direct measurement and observation. HR has been studied through a variety of mediums, e.g. deuterium footprints, soil moisture patterns and sap flow measurements. All three methods capture the moisture fluctuations within the soil layers via measurements of deuterium concentration, volumetric soil moisture content and root sap flow direction. The problem with deuterium labeling is that it does not allow for the persistent long term measurements over natural wetting and drying periods without additional irrigation. Sap flow measurements, despite having the ability to measure specific plant individuals' water dynamics, requires difficult access to the plant's root system which can be complex and difficult to sample. Soil moisture measurements can be made on a variety of sensor types and the installation is much less intensive. This study examines soil moisture measurements as a means for monitoring HR. Field observations in different regions of the United States utilizing different soil moisture sensor types (capacitance and reflectometer) are shown to exhibit similar diurnal soil moisture patterns common to the HR phenomenon. These observations are then compared and contrasted to model simulation results.

  18. Rapid measurement of field-saturated hydraulic conductivity for areal characterization

    Science.gov (United States)

    Nimmo, J.R.; Schmidt, K.M.; Perkins, K.S.; Stock, J.D.

    2009-01-01

    To provide an improved methodology for characterizing the field-saturated hydraulic conductivity (Kfs) over broad areas with extreme spatial variability and ordinary limitations of time and resources, we developed and tested a simplified apparatus and procedure, correcting mathematically for the major deficiencies of the simplified implementation. The methodology includes use of a portable, falling-head, small-diameter (???20 cm) single-ring infiltrometer and an analytical formula for Kfs that compensates both for nonconstant falling head and for the subsurface radial spreading that unavoidably occurs with small ring size. We applied this method to alluvial fan deposits varying in degree of pedogenic maturity in the arid Mojave National Preserve, California. The measurements are consistent with a more rigorous and time-consuming Kfs measurement method, produce the expected systematic trends in Kfs when compared among soils of contrasting degrees of pedogenic development, and relate in expected ways to results of widely accepted methods. ?? Soil Science Society of America. All rights reserved.

  19. Flow of variable-density formation water in deep sloping aquifers: minimizing the error in representation and analysis when using hydraulic-head distributions

    Science.gov (United States)

    Bachu, Stefan; Michael, Karsten

    2002-03-01

    Although not fully adequate, freshwater hydraulic heads have been used historically to represent and analyze variable-density flow in sloping aquifers in sedimentary basins. The use of environmental heads is valid only for strictly vertical flow in unconfined aquifers, while using variable-density hydraulic heads contravenes Darcy's law. Although the use of hydraulic-head surfaces is the simplest and quickest means of flow analysis and interpretation, preceding other methods such as numerical modeling, it introduces some errors that should be assessed and minimized in order to provide the most accurate flow representation. A first error is introduced when approximating the potential and buoyancy components along aquifer slope of the flow-driving force with their projections onto the horizontal plane. This error is most probably negligibly small for sloping aquifers in undisturbed sedimentary basins, but may be significant for aquifers dipping at a significant angle, such as in folded strata. A second error is introduced when using only hydraulic heads in the representation and analysis, and neglecting the buoyancy component of the flow-driving force. The significance of this error can be assessed by performing a Driving Force Ratio (DFR) analysis. There is no single or critical value of the DFR, below which the error in using hydraulic heads alone is negligible, and above which it is not acceptable anymore; rather, the decision regarding the error acceptability should and can be made on a case by case basis. The DFR, hence the errors in flow direction and magnitude, can be minimized for any given aquifer by using an optimum reference density in hydraulic-head calculations that is the areally-weighted average density of formation water in that aquifer. In flow analyses based on potentiometric surfaces, the use of freshwater as the reference density actually maximizes the errors introduced by the neglect of the buoyancy component of the flow-driving force because it

  20. Hydraulic characteristics of converse curvature section and aerator in high-head and large discharge spillway tunnel

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The hydraulic characteristics and cavitation erosion near the converse curvature section in the high-head and large discharge spillway tunnel have been important issues of concern to the hydropower project.In this paper,the evolutions of hydraulic elements such as pressure,flow velocity,wall shear stress,etc.in the converse curvature section are analyzed and the impacts of bottom aerator on hydraulic characteristics are discussed,with the commercial software FLUENT6.3 as a platform and combining the k-model and VOF method.The flow pattern in the converse curvature section of spillway tunnel is given by the three-dimensional numerical simulation.It indicates that the pressure changes rapidly with great pressure gradient from the beginning to the end of the curve.It also shows that the shear stress on side wall just downstream the end of the converse curvature curve is still increasing;the aeration cavity formed downstream the bottom aerator may cause the side wall pressure decreased to worsen the cavitation characteristics near the side wall.By means of the physical model experiment,the three-dimensional aerator composed of side wall baffling aerator and bottom aerator is studied,the baffling aerator suitable for the water flow conditions with water depth of 6.0 to 8.0 m and flow velocity of 35 to 50 m/s is proposed.

  1. Measurement of 3-D hydraulic conductivity in aquifer cores at in situ effective stresses.

    Science.gov (United States)

    Wright, Martin; Dillon, Peter; Pavelic, Paul; Peter, Paul; Nefiodovas, Andrew

    2002-01-01

    An innovative and nondestructive method to measure the hydraulic conductivity of drill core samples in horizontal and vertical directions within a triaxial cell has been developed. This has been applied to characterizing anisotropy and heterogeneity of a confined consolidated limestone aquifer. Most of the cores tested were isotropic, but hydraulic conductivity varied considerably and the core samples with lowest values were also the most anisotropic. Hydraulic conductivity decreased with increasing effective stress due to closure of microfractures caused by sampling for all core samples. This demonstrates the importance of replicating in situ effective stresses when measuring hydraulic conductivity of cores of deep aquifers in the laboratory.

  2. Empirical analysis of the stress-strain relationship between hydraulic head and subsidence in the San Joaquin Valley Aquifer

    Science.gov (United States)

    Neff, K. L.; Farr, T.

    2016-12-01

    Aquifer subsidence due to groundwater abstraction poses a significant threat to aquifer sustainability and infrastructure. The need to prevent permanent compaction to preserve aquifer storage capacity and protect infrastructure begs a better understanding of how compaction is related to groundwater abstraction and aquifer hydrogeology. The stress-strain relationship between hydraulic head changes and aquifer compaction has previously been observed to be hysteretic in both empirical and modeling studies. Here, subsidence data for central California's San Joaquin Valley derived from interferometric synthetic aperture radar (InSAR) for the period 2007-2016 is examined relative to hydraulic head levels in monitoring and production wells collected by the California Department of Water Resources. Such a large and long-term data set is available for empirical analysis for the first time thanks to advances in InSAR data collection and geospatial data management. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

  3. Characterisation of hydraulic head changes and aquifer properties in the London Basin using Persistent Scatterer Interferometry ground motion data

    Science.gov (United States)

    Bonì, R.; Cigna, F.; Bricker, S.; Meisina, C.; McCormack, H.

    2016-09-01

    In this paper, Persistent Scatterer Interferometry was applied to ERS-1/2 and ENVISAT satellite data covering 1992-2000 and 2002-2010 respectively, to analyse the relationship between ground motion and hydraulic head changes in the London Basin, United Kingdom. The integration of observed groundwater levels provided by the Environment Agency and satellite-derived displacement time series allowed the estimation of the spatio-temporal variations of the Chalk aquifer storage coefficient and compressibility over an area of ∼1360 km2. The average storage coefficient of the aquifer reaches values of 1 × 10-3 and the estimated average aquifer compressibility is 7.7 × 10-10 Pa-1 and 1.2 × 10-9 Pa-1 for the periods 1992-2000 and 2002-2010, respectively. Derived storage coefficient values appear to be correlated with the hydrogeological setting, where confined by the London Clay the storage coefficient is typically an order of magnitude lower than where the chalk is overlain by the Lambeth Group. PSI-derived storage coefficient estimates agree with the values obtained from pumping tests in the same area. A simplified one-dimensional model is applied to simulate the ground motion response to hydraulic heads changes at nine piezometers. The comparison between simulated and satellite-observed ground motion changes reveals good agreement, with errors ranging between 1.4 and 6.9 mm, and being 3.2 mm on average.

  4. Design Formulae for Hydraulic Stability and Structural Integrity of Dolos Breakwater Round-Heads

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Jensen, Jacob Birk; Liu, Z.

    1995-01-01

    A rational design of Dolos armour unit should incorporate both the hydraulic stability and the structural integrity. The previous tests performed by Aalborg University (AU) resulted in design formulae for the trunk of a 1:1.5 slope Dolos breakwater without superstructure including both...

  5. MEASURING VERTICAL PROFILES OF HYDRAULIC CONDUCTIVITY WITH IN SITU DIRECT-PUSH METHODS

    Science.gov (United States)

    U.S. EPA (Environmental Protection Agency) staff developed a field procedure to measure hydraulic conductivity using a direct-push system to obtain vertical profiles of hydraulic conductivity. Vertical profiles were obtained using an in situ field device-composed of a Geopr...

  6. Fracture hydraulic conductivity in the Mexico City clayey aquitard: Field piezometer rising-head tests

    Science.gov (United States)

    Vargas, Carlos; Ortega-Guerrero, Adrián

    A regional lacustrine aquitard covers the main aquifer of the metropolitan area of Mexico City. The aquitard's hydraulic conductivity (K') is fundamental for evaluating the natural protection of the aquifer against a variety of contaminants present on the surface and its hydraulic response. This study analyzes the distribution and variation of K' in the plains of Chalco, Texcoco and Mexico City (three of the six former lakes that existed in the Basin of Mexico), on the basis of 225 field-permeability tests, in nests of existing piezometers located at depths of 2-85 m. Tests were interpreted using the Hvorslev method and some by the Bouwer-Rice method. Results indicate that the distribution of K' fits log-Gaussian regression models. Dominant frequencies for K' in the Chalco and Texcoco plains range between 1E-09 and 1E-08 m/s, with similar population means of 1.19E-09 and 1.7E-09 m/s, respectively, which are one to two orders of magnitude higher than the matrix conductivity. In the Mexico City Plain the population mean is near by one order of magnitude lower; K'=2.6E-10 m/s. The contrast between the measured K' and that of the matrix is attributed to the presence of fractures in the upper 25-40 m, which is consistent with the findings of previous studies on solute migration in the aquitard. Un imperméable régional d'origine lacustre recouvre le principal aquifère de la zone urbaine de la ville de Mexico. La conductivité hydraulique K' de cet imperméable est fondamentale pour évaluer la protection naturelle de l'aquifère, contre les différents contaminants présents en surface, et sa réponse hydraulique. Cette étude analyse et les variations de K' dans les plaines de Chalco, Texcoco et Mexico (trois des six anciens lacs qui existaient dans le Bassin de Mexico), sur la base de 225 essais de perméabilité sur le terrain, réalisés en grappes dans des piézomètres existants entre 2 et 85 m de profondeur. Les essais ont été interprétés avec la m

  7. EVALUATION OF HYDRAULIC CONDUCTIVITIES CALCULATED FROM MULTIPORT-PERMEAMETER MEASUREMENTS

    Science.gov (United States)

    A multiport permeameter was developed for use in estimating hydraulic conductivity over intact sections of aquifer core using the core liner as the permeameter body. Six cores obtained from one borehole through the upper 9 m of a stratified glacial-outwash aquifer were used to ev...

  8. Digital Measuring Devices Used for Injector Hydraulic Test

    Directory of Open Access Journals (Sweden)

    S. N. Leontiev

    2015-01-01

    Full Text Available To ensure a high specific impulse of the LRE (liquid-propellant engine chamber it is necessary to have optimally organized combustion of the fuel components. This can be ensured by choosing the optimum geometry of gas-dynamic contour of the LRE combustor, as well as by improving the sputtering processes and mixing the fuel components, for example, by selection of the optimum type, characteristics, and location of injectors on the mixing unit of the chamber.These particular reasons arise the interest in the injector characteristics in terms of science, and technological aspects determine the need for control of underlying design parameters in their manufacture.The objective of this work is to give an experimental justification on used digital measurement instrumentation and research the hydraulic characteristics of injectors.To determine injector parameters most widely were used the units with sectional collectors. A technique to control injector parameters using the sectional collectors involves spraying the liquid by injector at a given pressure drop on it for a certain time (the longer, the higher the accuracy and reliability of the results and then determining the amount of liquid in each section to calculate the required parameters of injector.In this work the liquid flow through the injector was determined by high-precision flowmeters FLONET FN2024.1 of electromagnetic type, which have very high metrological characteristics, in particular a flow rate error does not exceed 0.5% in a range of water flow from Qmin= 0.0028 l/s to Qmax Qmax = 0.28 l/s. To determine the coefficient of uneven spray were used differential pressure sensors DMD 331-ASLX of company "DB Sensors RUS", which have an error of 0.075% with a range of differential pressure 0 ... 5 kPa. Measuring complex MIC-200 of company "NPP Measure" and WinPos software for processing array information provided entry, recording, and processing of all the data of the experiment.In this

  9. Uncertainty analysis of a combined Artificial Neural Network - Fuzzy logic - Kriging system for spatial and temporal simulation of Hydraulic Head.

    Science.gov (United States)

    Tapoglou, Evdokia; Karatzas, George P.; Trichakis, Ioannis C.; Varouchakis, Emmanouil A.

    2015-04-01

    The purpose of this study is to evaluate the uncertainty, using various methodologies, in a combined Artificial Neural Network (ANN) - Fuzzy logic - Kriging system, which can simulate spatially and temporally the hydraulic head in an aquifer. This system uses ANNs for the temporal prediction of hydraulic head in various locations, one ANN for every location with available data, and Kriging for the spatial interpolation of ANN's results. A fuzzy logic is used for the interconnection of these two methodologies. The full description of the initial system and its functionality can be found in Tapoglou et al. (2014). Two methodologies were used for the calculation of uncertainty for the implementation of the algorithm in a study area. First, the uncertainty of Kriging parameters was examined using a Bayesian bootstrap methodology. In this case the variogram is calculated first using the traditional methodology of Ordinary Kriging. Using the parameters derived and the covariance function of the model, the covariance matrix is constructed. A common method for testing a statistical model is the use of artificial data. Normal random numbers generation is the first step in this procedure and by multiplying them by the decomposed covariance matrix, correlated random numbers (sample set) can be calculated. These random values are then fitted into a variogram and the value in an unknown location is estimated using Kriging. The distribution of the simulated values using the Kriging of different correlated random values can be used in order to derive the prediction intervals of the process. In this study 500 variograms were constructed for every time step and prediction point, using the method described above, and their results are presented as the 95th and 5th percentile of the predictions. The second methodology involved the uncertainty of ANNs training. In this case, for all the data points 300 different trainings were implemented having different training datasets each time

  10. Transient pressure measurements at part load operating condition of a high head model Francis turbine

    Indian Academy of Sciences (India)

    RAHUL GOYAL; CHIRAG TRIVEDI; B K GANDHI; MICHEL J CERVANTES; OLE G DAHLHAUG

    2016-11-01

    Hydraulic turbines are operating at part load conditions depending on availability of hydraulic energy or to meet the grid requirements. The turbine experiences more fatigue during the part load operating conditions due to flow phenomena such as vortex breakdown in the draft tube and flow instability in the runner.The present paper focuses on the investigation of a high head model Francis turbine operating at 50% load.Pressure measurements have been carried out experimentally on a model Francis turbine. Total six pressure sensors were mounted inside the turbine and other two pressure sensors were mounted at the turbine inlet pipe. It is observed that the turbine experiences significant pressure fluctuations at the vaneless space and the runner.Moreover, a standing wave is observed between the pressure tank outlet and the turbine inlet. Analysis of the data acquired by the pressure sensors mounted in the draft tube showed the presence of vortex breakdown corotating with the runner. The detailed analysis showed the rotating and plunging components of the vortex breakdown. The influence of the rotating component was observed in the entire hydraulic circuit includingdistributor and turbine inlet but not the plunging one.

  11. 3D-Measuring for Head Shape Covering Hair

    Science.gov (United States)

    Kato, Tsukasa; Hattori, Koosuke; Nomura, Takuya; Taguchi, Ryo; Hoguro, Masahiro; Umezaki, Taizo

    3D-Measuring is paid to attention because 3D-Display is making rapid spread. Especially, face and head are required to be measured because of necessary or contents production. However, it is a present problem that it is difficult to measure hair. Then, in this research, it is a purpose to measure face and hair with phase shift method. By using sine images arranged for hair measuring, the problems on hair measuring, dark color and reflection, are settled.

  12. Real-time head acceleration measurement in girls' youth soccer.

    Science.gov (United States)

    Hanlon, Erin M; Bir, Cynthia A

    2012-06-01

    The purpose of the current study was to collect real-time head acceleration data for soccer impacts during girls' youth (U14) soccer play. Linear and angular head accelerations were collected during girls' youth soccer scrimmages using a wireless head acceleration measurement device (the Head Impact Telemetry System). After field data collection, each individual impact was analyzed. The type of impact, header or nonheader, was determined, and nonheader impacts were further assessed by the category of impact. The head injury criterion and resultant linear and angular accelerations were analyzed and compared with current injury tolerance values for all impacts. A total of 47 header and 20 nonheader impacts were observed during the study. The front of the head experienced more headers than the other locations (n = 17). Header impacts ranged in peak linear acceleration from 4.5 g to 62.9 g and in peak angular head acceleration from 444.8 to 8869.1 rad·s(-2). The majority of the nonheader impacts (40%) were player collisions with other players. Only one goalpost collision occurred, but it resulted in the highest peak angular acceleration (5179.5 rad·s(-2)) and was the only nonheader impact to exceed any of the tolerance levels. Head accelerations were found to exceed the majority of previous laboratory studies. None of the impacts exceeded linear acceleration tolerance values for concussion, but angular accelerations did exceed the suggested limits. Three angular acceleration measurements for heading events (4509.8, 5298.3, and 8869.1 rad·s(-2)) exceeded the concussion tolerance values, but no concussions were diagnosed during the study.

  13. Swath altimetry measurements of the mainstem Amazon River: measurement errors and hydraulic implications

    Science.gov (United States)

    Wilson, M. D.; Durand, M.; Jung, H. C.; Alsdorf, D.

    2014-08-01

    The Surface Water and Ocean Topography (SWOT) mission, scheduled for launch in 2020, will provide a step-change improvement in the measurement of terrestrial surface water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water surface elevations. In this paper, we aimed to (i) characterize and illustrate in two-dimensions the errors which may be found in SWOT swath measurements of terrestrial surface water, (ii) simulate the spatio-temporal sampling scheme of SWOT for the Amazon, and (iii) assess the impact of each of these on estimates of water surface slope and river discharge which may be obtained from SWOT imagery. We based our analysis on a "virtual mission" for a 300 km reach of the central Amazon (Solimões) River at its confluence with the Purus River, using a hydraulic model to provide water surface elevations according to SWOT spatio-temporal sampling to which errors were added based on a two-dimension height error spectrum derived from the SWOT design requirements. We thereby obtained water surface elevation measurements for the Amazon mainstem as may be observed by SWOT. Using these measurements, we derived estimates of river slope and discharge and compared them to those obtained directly from the hydraulic model. We found that cross-channel and along-reach averaging of SWOT measurements using reach lengths of greater than 4 km for the Solimões and 7.5 km for Purus reduced the effect of systematic height errors, enabling discharge to be reproduced accurately from the water height, assuming known bathymetry and friction. Using cross-section averaging and 20 km reach lengths, results show Nash-Sutcliffe model efficiency values of 0.99 for the Solimões and 0.88 for the Purus, with 2.6 and 19.1% average overall error in discharge, respectively.

  14. Swath altimetry measurements of the mainstem Amazon River: measurement errors and hydraulic implications

    Directory of Open Access Journals (Sweden)

    M. D. Wilson

    2014-08-01

    Full Text Available The Surface Water and Ocean Topography (SWOT mission, scheduled for launch in 2020, will provide a step-change improvement in the measurement of terrestrial surface water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water surface elevations. In this paper, we aimed to (i characterize and illustrate in two-dimensions the errors which may be found in SWOT swath measurements of terrestrial surface water, (ii simulate the spatio-temporal sampling scheme of SWOT for the Amazon, and (iii assess the impact of each of these on estimates of water surface slope and river discharge which may be obtained from SWOT imagery. We based our analysis on a "virtual mission" for a 300 km reach of the central Amazon (Solimões River at its confluence with the Purus River, using a hydraulic model to provide water surface elevations according to SWOT spatio-temporal sampling to which errors were added based on a two-dimension height error spectrum derived from the SWOT design requirements. We thereby obtained water surface elevation measurements for the Amazon mainstem as may be observed by SWOT. Using these measurements, we derived estimates of river slope and discharge and compared them to those obtained directly from the hydraulic model. We found that cross-channel and along-reach averaging of SWOT measurements using reach lengths of greater than 4 km for the Solimões and 7.5 km for Purus reduced the effect of systematic height errors, enabling discharge to be reproduced accurately from the water height, assuming known bathymetry and friction. Using cross-section averaging and 20 km reach lengths, results show Nash–Sutcliffe model efficiency values of 0.99 for the Solimões and 0.88 for the Purus, with 2.6 and 19.1% average overall error in discharge, respectively.

  15. Effects of hedgerow systems on soil moisture and unsaturated hydraulics conductivity measured by the Libardi method

    Directory of Open Access Journals (Sweden)

    S . Prijono

    2016-01-01

    Full Text Available The hedgerow systems are the agroforestry practices suggesting any positive impacts and negative impacts on soil characteristics. This study evaluated the effects of hedgerows on the unsaturated hydraulic conductivity of soil with the Libardi method approach. This study was conducted in North Lampung for 3 months on the hedgerow plots of Peltophorum dassyrachis (P, Gliricidia sepium (G, and without hedgerow plot (K, with four replications. Each plot was watered as much as 150 liters of water until saturated, then the soil surface were covered with the plastic film. Observation of soil moisture content was done to a depth of 70 cm by the 10 cm intervals. Soil moisture content was measured using the Neutron probe that was calibrated to get the value of volumetric water content. Unsaturated hydraulic conductivity of soil was calculated by using the Libardi Equation. Data were tested using the analysis of variance, the least significant different test (LSD, Duncan Multiple Range Test (DMRT, correlation and regression analysis. The results showed that the hedgerow significantly affected the soil moisture content and unsaturated hydraulic conductivity. Soil moisture content on the hedgerow plots was lower than the control plots. The value of unsaturated hydraulic conductivity in the hedgerow plots was higher than the control plots. Different types of hedgerows affected the soil moisture content and unsaturated hydraulic conductivity. The positive correlation was found between the volumetric soil moisture content and the unsaturated hydraulic conductivity of soil.

  16. A geostatistical methodology for the optimal design of space-time hydraulic head monitoring networks and its application to the Valle de Querétaro aquifer.

    Science.gov (United States)

    Júnez-Ferreira, H E; Herrera, G S

    2013-04-01

    This paper presents a new methodology for the optimal design of space-time hydraulic head monitoring networks and its application to the Valle de Querétaro aquifer in Mexico. The selection of the space-time monitoring points is done using a static Kalman filter combined with a sequential optimization method. The Kalman filter requires as input a space-time covariance matrix, which is derived from a geostatistical analysis. A sequential optimization method that selects the space-time point that minimizes a function of the variance, in each step, is used. We demonstrate the methodology applying it to the redesign of the hydraulic head monitoring network of the Valle de Querétaro aquifer with the objective of selecting from a set of monitoring positions and times, those that minimize the spatiotemporal redundancy. The database for the geostatistical space-time analysis corresponds to information of 273 wells located within the aquifer for the period 1970-2007. A total of 1,435 hydraulic head data were used to construct the experimental space-time variogram. The results show that from the existing monitoring program that consists of 418 space-time monitoring points, only 178 are not redundant. The implied reduction of monitoring costs was possible because the proposed method is successful in propagating information in space and time.

  17. Locations, values, and uncertainties of hydraulic-head observations for the steady-state, prepumped period of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital geospatial data set contains the locations, values, and uncertainties of 700 hydraulic-head observations used in the steady-state, prepumped period of...

  18. Issues on Dummy-Head HRTFs measurements

    DEFF Research Database (Denmark)

    Toledo, Daniela; Møller, Henrik

    2009-01-01

    The dimensions of a person are small compared to the wavelength at low frequencies. Therefore, at these frequencies HRTFs should decrease asymptotically until they reach 0dB -i.e. unity gain- at DC. This is not the case in measured HRTFs: the limitations of the equipment used result in a wrong -a...

  19. Hydraulic Conductivity Measurements with HTU at Eurajoki, Olkiluoto, Borehole OL-KR15 and OL-KR15B, Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H.

    2005-07-01

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out in borehole OL-KR15 at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during 2003-2004 in two phases. The total length of the borehole OL-KR15 is 518,85 m and 158 45,14 m. Of the 471 ,5 m + 44,5 m total measurable length 414 m was covered with 237 standard tests with 2 m packer separation as specified in the research plan, partly with 1 m overlaps. 259 tests were initiated, but some of them ended to hardware or software errors or unsuitable parameter values. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the stabilisation or injection stage lasted several hours. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  20. Evaluation of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. Part 1. Single-stage regulated pump turbines for operating heads of 500 to 1000 m

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, A.A.; Blomquist, C.A.; Degnan, J.R.

    1979-10-01

    High-head, large-capacity turbomachinery is needed for the concept of underground pumped hydroelectric storage to be technically and economically attractive. Single-stage, reversible, Francis-type pump turbines with adjustable wicket gates appear to offer the most economically attractive option for heads between about 500 and 1000 m. The feasibility of developing these types of machines for capacities up to 500 MW and operating heads up to 1000 m has been evaluated. Preliminary designs have been generated for six single-stage pump turbines. The designs are for capacities of 350 and 500 MW and for operating heads of 500, 750, and 1000 m. The report contains drawings of the machines along with material specifications and hydraulic performance data. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost. The stress and deflection responses of the 500-MW, 100-m-head pump turbine, determined by detailed finite element analysis techniques, give solid evidence of the integrity of the conceptual designs of the six units and indicate no unsolvable problems. Results of a life expectancy analysis of the wicket gates indicate that a near infinite life can be expected for these components when they are subjected to normal design loads. Efficiencies of 90.7 and 91.4% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1000-m-head unit. Performances of the other five machines are comparable. The specific costs of the pump turbines in mid-1978 US dollars per kW vary from 19.2 to 11.8 over a head range of from 500 to 1000 m for the 500-MW machines and from 20.0 to 12.3 for the 350-MW machines.

  1. Long-term geochemical and hydraulic measurements in a characteristic confined/unconfined aquifer system of the younger Pleistocene in northeast Germany

    Directory of Open Access Journals (Sweden)

    C. Merz

    2015-01-01

    Full Text Available The paper presents a data base of hydrochemical and hydraulic groundwater measurements of a younger Pleistocene multilayered, unconfined/confined aquifer system in NE Germany. The Institute of Landscape Hydrology of the Leibniz Centre for Agricultural Landscape Research (ZALF e. V. operates seven groundwater monitoring wells in the Quillow catchment located in the Uckermark region (Federal State of Brandenburg, Germany. From July 2000 to March 2014, water samples were collected periodically on different days of the year and at depths between 3 and 5 m (shallow wells and 20 and 25 m (deeper wells below the surface. The parameters pH value, redox potential, electric conductivity, water temperature, oxygen content, spectral absorption coefficient and concentration of hydrogen carbonate, ammonium, phosphate, chloride, bromite, nitrite, sulfate, sodium, potassium, magnesium, calcite, dissolved organic carbon, iron(II and manganese were determined for each sample (doi:10.4228/ZALF.2000.266. The measurements, taken over a period of 14 years, include a high variation of hydraulic situations represented by a corresponding database of detected groundwater heads. The hydraulic head was measured between 2000 and 2014 (doi:10.4228/ZALF.2000.272.

  2. Evaluation of Hydraulic Parameters Obtained by Different Measurement Methods for Heterogeneous Gravel Soil

    Directory of Open Access Journals (Sweden)

    Chen Zeng

    2012-01-01

    Full Text Available Knowledge of soil hydraulic parameters for the van Genuchten function is important to characterize soil water movement for watershed management. Accurate and rapid prediction of soil water flow in heterogeneous gravel soil has become a hot topic in recent years. However, it is difficult to precisely estimate hydraulic parameters in a heterogeneous soil with rock fragments. In this study, the HYDRUS-2D numerical model was used to evaluate hydraulic parameters for heterogeneous gravel soil that was irregularly embedded with rock fragments in a grape production base. The centrifugal method (CM, tensiometer method (TM and inverse solution method (ISM were compared for various parameters in the van Genuchten function. The soil core method (SCM, disc infiltration method (DIM and inverse solution method (ISM were also investigated for measuring saturated hydraulic conductivity. Simulation with the DIM approach revealed a problem of overestimating soil water infiltration whereas simulation with the SCM approach revealed a problem of underestimating water movement as compared to actual field observation. The ISM approach produced the best simulation result even though this approach slightly overestimated soil moisture by ignoring the impact of rock fragments. This study provides useful information on the overall evaluation of soil hydraulic parameters attained with different measurement methods for simulating soil water movement and distribution in heterogeneous gravel soil.

  3. Getting saturated hydraulic conductivity from surface Ground-Penetrating Radar measurements inside a ring infiltrometer

    Science.gov (United States)

    Leger, E.; Saintenoy, A.; Coquet, Y.

    2013-12-01

    fixed time steps, during an infiltration of 5 cm of water, inside a ring infiltrometer. We used the ring to demarcate the infiltration area, and to create reflexions at known depths. GPR reflexions coming from the wetting front as well as the buried edges of the cylinder were recorded. Modeling of the infiltration were made using SWMS-2D, GPR data of the infiltration were computed using GprMax suite programs. We generated 2D water content profiles associated with a saturated hydraulic conductivity value, at each experimental time step with SWMS-2D. Then we convert those profiles to 2D permittivity profiles using the Complex Refractive Index Method relation, to compute the reflexion time of the wetting front. We found the saturated hydraulic conductivity of soil by minimizing the differences between experimental and simulated data. Our retrieved saturated hydraulic conductivity from GPR data was compared to disk infiltrometer measurements.

  4. Swath-altimetry measurements of the main stem Amazon River: measurement errors and hydraulic implications

    Science.gov (United States)

    Wilson, M. D.; Durand, M.; Jung, H. C.; Alsdorf, D.

    2015-04-01

    The Surface Water and Ocean Topography (SWOT) mission, scheduled for launch in 2020, will provide a step-change improvement in the measurement of terrestrial surface-water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water-surface elevations. In this paper, we aimed to (i) characterise and illustrate in two dimensions the errors which may be found in SWOT swath measurements of terrestrial surface water, (ii) simulate the spatio-temporal sampling scheme of SWOT for the Amazon, and (iii) assess the impact of each of these on estimates of water-surface slope and river discharge which may be obtained from SWOT imagery. We based our analysis on a virtual mission for a ~260 km reach of the central Amazon (Solimões) River, using a hydraulic model to provide water-surface elevations according to SWOT spatio-temporal sampling to which errors were added based on a two-dimensional height error spectrum derived from the SWOT design requirements. We thereby obtained water-surface elevation measurements for the Amazon main stem as may be observed by SWOT. Using these measurements, we derived estimates of river slope and discharge and compared them to those obtained directly from the hydraulic model. We found that cross-channel and along-reach averaging of SWOT measurements using reach lengths greater than 4 km for the Solimões and 7.5 km for Purus reduced the effect of systematic height errors, enabling discharge to be reproduced accurately from the water height, assuming known bathymetry and friction. Using cross-sectional averaging and 20 km reach lengths, results show Nash-Sutcliffe model efficiency values of 0.99 for the Solimões and 0.88 for the Purus, with 2.6 and 19.1 % average overall error in discharge, respectively. We extend the results to other rivers worldwide and infer that SWOT-derived discharge estimates may be more accurate for rivers with larger channel widths (permitting a greater level of cross

  5. Confined aquifer head measurements and storage properties in the San Luis Valley, Colorado, from spaceborne InSAR observations

    Science.gov (United States)

    Chen, Jingyi; Knight, Rosemary; Zebker, Howard A.; Schreüder, Willem A.

    2016-05-01

    Interferometric Synthetic Aperture Radar (InSAR), a remote sensing technique for measuring centimeter-level surface deformation, is used to estimate hydraulic head in the confined aquifer of the San Luis Valley (SLV), Colorado. Reconstructing head measurements from InSAR in agricultural regions can be difficult, as InSAR phase data are often decorrelated due to vegetation growth. Analysis of 17 L-band ALOS PALSAR scenes, acquired between January 2007 and March 2011, demonstrates that comprehensive InSAR deformation measurements can be recovered over the vegetated groundwater basin with an improved processing strategy. Local skeletal storage coefficients and time delays between the head change and deformation are estimated through a joint InSAR-well data analysis. InSAR subsidence estimates are transformed to head changes with finer temporal and spatial resolution than is possible using existing well records alone. Both InSAR and well data suggest that little long-term water-storage loss occurred in the SLV over the study period and that inelastic compaction was negligible. The seasonal head variations derived from InSAR are consistent with the existing well data at most locations where confined aquifer pumping activity dominates. Our results demonstrate the advantages of InSAR measurements for basin-wide characterization of aquifer storage properties and groundwater levels over agricultural regions.

  6. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  7. Hydraulic Inferences for Mars From Geologic Mapping in Margaritifer Terra, Mars and Measurements of Terrestrial Analogs.

    Science.gov (United States)

    Fortezzo, C. M.; Williams, K. K.; Springer, A. E.

    2006-12-01

    Past hydrogeologic models of Mars have focused primarily on exploring a link between large scale groundwater systems and the Martian outflow channels. These groundwater models have generally given only slight consideration to the occurrence of smaller-scale valley network that dissect much of the southern highlands. Ongoing geologic and geomorphic mapping in 6 Mars Transverse Mercator 1:500K quadrangles (17.5ºS - 27.5ºS and 345ºE - 360ºE) in southeast Margaritifer Terra, Mars, shows valley networks are often associated with the internal and external slopes of the impact basin but are absent on the basin floor. We propose a sequence of ponding in the basin followed by infiltration into the subsurface, transmission down the regional slope and sapping valleys forming on the crater flanks. The Martian valley morphologies are analogous with morphologies of terrestrial spring-fed sapping processes (i.e., amphitheater-shaped heads, stubby tributaries, steep walls, and U-shaped valleys that maintain consistent width-depth ratios along their length). Flow measurements from spring-fed channels in the Navajo Sandstone near Escalante, Utah supply data from areas actively forming sapping valleys and provide insight into the interaction between surface-water and groundwater. Measurements taken during pre-monsoon and post-snow melt run-off and planned post- monsoonal measurements will provide a range of discharge values furnishing data to model the interaction of subsurface- and surface-water flow on Mars. Published stratigraphic models of Mars postulate that the upper kilometer of material is ejecta related well-mixed unsorted debris ranging from meter sized blocks down to dust sized particles overlying fractured bedrock. Detailed mapping using high resolution datasets allows for accurate characterization of surficial material properties on a local scale which will help to better understand influences on hydrologic variables (i.e. permeability, hydraulic conductivity, etc

  8. Static and dynamic stress analyses of the prototype high head Francis runner based on site measurement

    Science.gov (United States)

    Huang, X.; Oram, C.; Sick, M.

    2014-03-01

    More efforts are put on hydro-power to balance voltage and frequency within seconds for primary control in modern smart grids. This requires hydraulic turbines to run at off-design conditions. especially at low load or speed-no load. Besides. the tendency of increasing power output and decreasing weight of the turbine runners has also led to the high level vibration problem of the runners. especially high head Francis runners. Therefore. it is important to carry out the static and dynamic stress analyses of prototype high head Francis runners. This paper investigates the static and dynamic stresses on the prototype high head Francis runner based on site measurements and numerical simulations. The site measurements are performed with pressure transducers and strain gauges. Based on the measured results. computational fluid dynamics (CFD) simulations for the flow channel from stay vane to draft tube cone are performed. Static pressure distributions and dynamic pressure pulsations caused by rotor-stator interaction (RSI) are obtained under various operating conditions. With the CFD results. static and dynamic stresses on the runner at different operating points are calculated by means of the finite element method (FEM). The agreement between simulation and measurement is analysed with linear regression method. which indicates that the numerical result agrees well with that of measurement. Furthermore. the maximum static and dynamic stresses on the runner blade are obtained at various operating points. The relations of the maximum stresses and the power output are discussed in detail. The influences of the boundary conditions on the structural behaviour of the runner are also discussed.

  9. In-situ falling-head test for hydraulic conductivity: Evaluation in layered sediments of an analysis derived for homogenous sediments

    Science.gov (United States)

    Burnette, Matthew C.; Genereux, David P.; Birgand, François

    2016-08-01

    The hydraulic conductivity (K) of streambeds is a critical variable controlling interaction of groundwater and surface water. The Hvorslev analysis for estimating K from falling-head test data has been widely used since the 1950s, but its performance in layered sandy sediments common in streams and lakes has not previously been examined. Our numerical simulations and laboratory experiments show that the Hvorslev analysis yields accurate K values in both homogenous sediment (for which the analysis was originally derived) and layered deposits with low-K sand over high-K sand. K from the Hvorslev analysis deviated significantly from true K only when two conditions were present together: (1) high-K sand was present over low-K sand, and (2) the bottom of the permeameter in which K was measured was at or very near the interface between high-K and low-K. When this combination of conditions exists, simulation and laboratory sand tank results show that in-situ Hvorslev K underestimates the true K of the sediment within a permeameter, because the falling-head test is affected by low-K sediment outside of (below the bottom of) the permeameter. In simulation results, the maximum underestimation (occurring when the bottom of the permeameter was at the interface of high K over low K) was by a factor of 0.91, 0.59, and 0.12 when the high-K to low-K ratio was 2, 10, and 100, respectively. In laboratory sand tank experiments, the underestimation was by a factor of about 0.83 when the high-K to low-K ratio was 2.3. Also, this underestimation of K by the Hvorslev analysis was about the same whether the underlying low-K layer was 2 cm or 174 cm thick (1% or 87% of the domain thickness). Numerical model simulations were useful in the interpretation of in-situ field K profiles at streambed sites with layering; specifically, scaling the model results to the maximum measured K at the top of the field K profiles helped constrain the likely ratio of high K to low K at field locations with

  10. Measuring humeral head translation using fluoroscopy: a validation study.

    Science.gov (United States)

    San Juan, Jun G; Karduna, Andrew R

    2010-03-03

    Numerous techniques have been employed to monitor humeral head translation due to its involvement with several shoulder pathologies. However, most of the techniques were not validated. The objective of this study is to compare the accuracy of manual digitization and contour registration in measuring superior translation of the humeral head. Eight pairs of cadaver scapulae and humerii bones were harvested for this study. Each scapula and humerus was secured in a customized jig that allowed for control of humeral head translations and a vise that permitted rotations of the scapula about three axes. Fluoroscopy was used to take images of the shoulder bones. Scapular orientation was manipulated in different positions while the humerus was at 90 degrees of humeral elevation in the scapular plane. Humeral head translation was measured using the two methods and was compared to the known translation. Additionally, accuracy of the contour registration method to measure 2-D scapular rotations was assessed. The range for the root mean square (RMS) error for manual digitization method was 0.27 mm-0.43 mm and the contour registration method had a RMS error ranging from 0.18 mm-0.40 mm. In addition, the RMS error for the scapular angle rotation using the contour registration method was 2.4 degrees . Both methods showed acceptable errors. However, on average, the contour registration method showed lesser measurement error compared to the manual digitization method. In addition, the contour registration method was able to show good accuracy in measuring rotation that is useful in 2-D image analysis.

  11. Understanding Quality Measures in Otolaryngology–Head and Neck Surgery

    Science.gov (United States)

    Vila, Peter M.; Schneider, John S.; Piccirillo, Jay F.; Lieu, Judith E. C.

    2017-01-01

    As health care reimbursements based on pay-for-performance models become more common, there is an unprecedented demand for ways to measure health care quality and demonstrate value. Performance measures, a type of quality measure, are unique tools in a health care delivery system that allow objective monitoring of adherence to specific goals and tracking of outcomes. We sought to provide information on the development of quality measures in otolaryngology–head and neck surgery, as well as the goals of performance measurement at a national level and for our specialty. The historical development, various types, and approach to creating effective performance measures are discussed. The primary methods of developing performance measures (using clinical practice guidelines, clinical registries, and alternative methods) are also discussed. Performance measures are an important tool that can aid otolaryngologists in achieving effective, efficient, equitable, timely, safe, and patient-centered care as outlined by the Institute of Medicine. PMID:26606715

  12. Efficiency measurements in low head hydro power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ramdal, Jorgen

    2011-07-01

    The work presented in this thesis involves efficiency measurements performed with the thermodynamic method and the pressure time method. The thermodynamic method has limitations with regards to the power plant head, as uncertainty will increase as the head becomes low. The Pressure-Time method has limitations concerning geometrical properties of the waterways, as it demands a certain length of closed conduit with uniform area. Both methods are considered to cause relatively short downtime for turbines to be measured, an dit is therefore of interest, for economical reasons, to expand the use of the methods to more power plants. In the thermodynamic method, a large source of errors and uncertainties comes from flow and temperature variations in the draft tube outlet. To investigate if this source of errors and uncertainties could be reduced, a setup with multipoint temperature and velocity measurements was installed in a low head hydro power plant. The general conclusion is that a multipoint measurement is beneficial in connection with low head measurements.Uncertainty from temperature variations in the water from the reservoir, and difference in the energy at the inlet is also discussed. For the Pressure-Time method, this thesis presents investigations made with shorter distances between measurement cross sections than prescribed in the standards, and with bends between the measurement cross sections. The investigations were performed both in laboratory and in a field measurement. For laboratory experiments it was also investigated if developed models for unsteady friction could be used to correct the flow estimates. The general conclusions are: Measurements with short distances should not introduce large errors, but the uncertainty and spread of measured points will increase. Bends give an underestimation of the flow rate that, under certain circumstances, is constant independent of initial velocity. How large the underestimation ratio will be can yet not be

  13. A low cost apparatus for measuring the xylem hydraulic conductance in plants

    Directory of Open Access Journals (Sweden)

    Luciano Pereira

    2012-01-01

    Full Text Available Plant yield and resistance to drought are directly related to the efficiency of the xylem hydraulic conductance and the ability of this system to avoid interrupting the flow of water. In this paper we described in detail the assembling of an apparatus proposed by TYREE et al. (2002, and its calibration, as well as low cost adaptations that make the equipment accessible for everyone working in this research area. The apparatus allows measuring the conductance in parts of roots or shoots (root ramifications or branches, or in the whole system, in the case of small plants or seedlings. The apparatus can also be used to measure the reduction of conductance by embolism of the xylem vessels. Data on the hydraulic conductance of eucalyptus seedlings obtained here and other reports in the literature confirm the applicability of the apparatus in physiological studies on the relationship between productivity and water stress.

  14. Measurement of LINAC 90 degrees head leakage radiation TVL values.

    Science.gov (United States)

    Li, Zuofeng; Mutic, Sasa; Low, Daniel

    2006-09-01

    One of the key components in modern LINAC room shielding design is the amount of 90 degrees head leakage radiation levels. With the general clinical acceptance of intensity-modulated radiation therapy (IMRT) technique, accurate knowledge of this quantity has become even more important. Measurement of 90 degrees head leakage radiation of medical linear accelerators can be technically challenging due to the low dose rate causing poor signal-to-noise ratios in most detectors. 90 degrees leakage tenth-value layer (TVL) values in concrete have not been reported for the Elekta linear accelerators. This report describes our measurements of 90 degrees leakage TVL values for 6, 10, and 18 MV x-ray beams for an Elekta Precise Treatment System. A large-volume (1000 cm3) unpressurized ionization chamber and a high sensitivity electrometer, together with a separate chamber bias power supply, were used in these measurements in order to maximize the signal-to-noise ratio. A lead enclosure, of minimum thickness 10 cm, was constructed inside the treatment room to house the ion chamber to reduce the influence of room-scattered radiation. A square aperture of 10 X 10 cm2 area was left in the shield and aimed towards the accelerator head. Measurements were performed with the chamber placed at approximately 2 m from the accelerator isocenter. Concrete slabs with individual dimensions of approximately 40 X 40 cm2 cross-sectional area and 5 cm thickness were placed between the accelerator head and the ion chamber for these measurements. The measurements were performed with total concrete thickness of up to 80 cm, so that values up to the third TVL were measured. These measurements showed thatthe first concrete TVL values are 22, 23, and 28 cm (8.6, 9.1, and 10.5 in.) for 6, 10, and 18 MV beams, while the average of the first 3 TVL's were 25, 26, and 29 cm (9.9, 10.2, and 11.5 in.). Measured values agreed to within 10% of previously reported values for Varian linear accelerators for

  15. Research and application of coal and gas outburst control measure based on hydraulic extrusion in roadway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, M.; Pan, H.; Li, Y.; Hu, B.; Chen, W. [Henan Polytechnic University, Jiaozuo (China)

    2007-02-15

    The technology system and equipment of hydraulic extrusion were presented. Based on the actual conditions of Liyi Coal Mine, reasonable parameters of injecting water were studied. The measure caused the stress concentration region of the coal seam to move forward, the pressure relief region was widened, and gas was released efficiently. The remarkable effect of coal and gas outburst prevention was achieved and the roadway driving speed was increased by 1.5 times. 7 refs., 5 figs.

  16. Development of a Test Apparatus for Measurement of Hydraulic Fluid Efficiency

    Institute of Scientific and Technical Information of China (English)

    Matt Jackson; Brian Koehler

    2011-01-01

    With increasing demand for nonrenewable resources,energy conservation is critical.Efficiency gains allow more work to be performed while maintaining or even decreasing the energy expended in the process.Reducing the energy consumed by a system results in favorable economic and environmental impact.An apparatus has been developed to measure hydraulic fluid efficiency in a stationary application.The system can be used to develop more efficient fluids,leading to increased work output or decreased energy consumption.

  17. Comparison of Measured and Modelled Hydraulic Conductivities of Fractured Sandstone Cores

    Science.gov (United States)

    Baraka-Lokmane, S.; Liedl, R.; Teutsch, G.

    - A new method for characterising the detailed fracture geometry in sandstone cores is presented. This method is based on the impregnation of samples with coloured resin, without significant disturbance of the fractures. The fractures are made clearly visible by the resin, thus allowing the fracture geometry to be examined digitally. In order to model the bulk hydraulic conductivity, the samples are sectioned serially perpendicular to the flow direction. The hydraulic conductivity of individual sections is estimated by summing the contribution of the matrix and each fracture from the digital data. Finally, the hydraulic conductivity of the bulk sample is estimated by a harmonic average in series along the flow path. Results of this geometrical method are compared with actual physical conductivity values measured from fluid experiments carried out prior to sectioning. The predicted conductivity from the fracture geometry parameters (e.g., fracture aperture, fracture width, fracture length and fracture relative roughness all measured using an optical method) is in good agreement with the independent physical measurements, thereby validating the approach.

  18. Indirect measurements of field-scale hydraulic conductivity of waste from two landfill sites.

    Science.gov (United States)

    Fleming, I R

    2011-12-01

    Management and prediction of the movement and distribution of fluids in large landfills is important for various reasons. Bioreactor landfill technology shows promise, but in arid or semi-arid regions, the natural content of landfilled waste may be low, thus requiring addition of significant volumes of water. In more humid locations, landfills can become saturated, flooding gas collection systems and causing sideslope leachate seeps or other undesirable occurrences. This paper compares results from two different approaches to monitoring water in waste. At the Brock West Landfill in eastern Canada, positive pore pressures were measured at various depths in saturated waste. The downward seepage flux through the waste is known, thus the vertical saturated hydraulic conductivity of the waste at this landfill was determined to be 3 × 10(-7)cm/s. By comparison, the Spadina Landfill in western Canada is predominantly unsaturated. The infiltration of moisture into the waste was measured using moisture sensors installed in boreholes which determined arrival time for moisture fronts resulting from major precipitation events as well as longer-term change in moisture content resulting from unsaturated drainage during winter when frozen ground prevented infiltration. The unsaturated hydraulic conductivity calculated from these data ranged from approximately 10(-6)cm/s for the slow winter drainage in the absence of significant recharge to 10(-2)cm/s or higher for shallow waste subject to high infiltration through apparent preferential pathways. These two very different approaches to field-scale measurements of vertical hydraulic conductivity provide insight into the nature of fluid movement in saturated and unsaturated waste masses. It is suggested that the principles of unsaturated seepage apply reasonably well for landfilled waste and that the hydraulic behavior of waste is profoundly influenced by the nature and size of voids and by the degree of saturation prevailing in the

  19. Hydraulic conductivity measurements with HTU at Eurajoki, Olkiluoto, drillholes OL-KR52 and OL-KR47 in 2013 and 2014

    Energy Technology Data Exchange (ETDEWEB)

    Hurmerinta, E. [Poeyry Finland Oy, Vantaa (Finland)

    2014-09-15

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out with the HTU-equipment in drillholes OL KR52 and OL KR47 on the Olkiluoto investigation site. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. In OL-KR52 measurements were carried out between February 2013 and April 2013 and in OL-KR47 between October 2013 and February 2014. The total length of the drillhole OL-KR52 is 427.35 m, 376.00 m of which was covered by 188 standard tests with 2 m packer separation as specified in the measurement plan. Respectively, OL-KR47 is 1008.76 m long and 312 similar tests were conducted in it covering 624.00 m of the drillhole. These numbers include one equipment test measurement near the surface in OL-KR47. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the test stage times were extended if longer times were needed to obtain correct results or when suited to the working schedule. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Poeyry Finland Oy in co-operation with Geopros Oy. (orig.)

  20. Hydraulic conductivity measurements with HTU at Eurajoki, Olkiluoto, drillholes OL-KR19, OL-KR45 and OL-KR46 in 2009 and 2010

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H. [Geopros Oy, Helsinki (Finland)

    2011-10-15

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out with HTU-equipment in drillholes OL-KR19, OL-KR45 and OL-KR46 at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during 2009 and 2010. The total length of the borehole OL-KR19 is 544,34 m, 241,80 m of which was covered by 121 standard tests with 2 m packer separation as specified in the measurement plan. Respectively, OL-KR45 is 1023,30 m long and 63 similar tests were made in it covering 126,00 m of the hole and OL-KR46 600,10 m long, 151 tests made covering 301,35 m. The measured sections are around the depths of the planned repository. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the test stage times were extended. Two transient (Horner and 1/Q) interpretations and one stationary- state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  1. Isotopic and Hydraulic Head Evidence for Cross-formational Leakage of Saline Water From the Rio Grande Alluvium to the Hueco Bolson Aquifer, Trans-Pecos Texas

    Science.gov (United States)

    Hibbs, B. J.; Eastoe, C. J.; Bangs, E.; Reinert, S.

    2002-12-01

    The twin-cities of El Paso and Juarez share the water resources of the Hueco Bolson, a Tertiary and Quaternary basin fill aquifer that spans the international border. Artesian conditions existed in the El Paso-Juarez Valley during predevelopment times, and dilute groundwaters in the Hueco Bolson flowed upward and mixed with the mineralized water in the shallow Rio Grande alluvium (alluvial deposits less than 60 m thick). The hydraulic gradient has been reversed since predevelopment times by heavy municipal pumping in the Hueco Bolson aquifer, and many of the deeper wells in the El Paso-Juarez Valley have been retired due to salinity exceeding 1500 mg/L TDS. Previous studies based on groundwater modeling suggested that salinity increased in deeper wells due to induced leakage of saline water from the shallow Rio Grande alluvium. Hydrochemical, isotopic and hydraulic head data collected in this study support this model. Tritium levels in several deeper wells in the El Paso-Juarez Valley (screens set from 90 to 210 m) vary from 1.2 to 7.9 TU, indicating post-bomb water from leakage from the Rio Grande and Rio Grande alluvium. The hydraulic head gradient is oriented vertically downward between the alluvial and bolson aquifers, reaching 0.14 (27 m/189 m) in one well nest. Groundwater from the same well nest gives δ18O and δ2H values plotting along a mixing curve, representing evaporated and saline waters in shallow alluvial wells (-7.2 to -8.3 δ18O \\permil, -66 to -71 δ2H \\permil), meteoric and dilute waters in the deepest bolson well (-10.7 δ18O \\permil, -76 δ2H \\permil), and intermediate and mixed saline water in middle bolson wells (-9.8 to -10.3 δ18O \\permil, -76 to -77 δ2H \\permil).

  2. Low-field NMR logging sensor for measuring hydraulic parameters of model soils

    Science.gov (United States)

    Sucre, Oscar; Pohlmeier, Andreas; Minière, Adrien; Blümich, Bernhard

    2011-08-01

    SummaryKnowing the exact hydraulic parameters of soils is very important for improving water management in agriculture and for the refinement of climate models. Up to now, however, the investigation of such parameters has required applying two techniques simultaneously which is time-consuming and invasive. Thus, the objective of this current study is to present only one technique, i.e., a new non-invasive method to measure hydraulic parameters of model soils by using low-field nuclear magnetic resonance (NMR). Hereby, two model clay or sandy soils were respectively filled in a 2 m-long acetate column having an integrated PVC tube. After the soils were completely saturated with water, a low-field NMR sensor was moved up and down in the PVC tube to quantitatively measure along the whole column the initial water content of each soil sample. Thereafter, both columns were allowed to drain. Meanwhile, the NMR sensor was set at a certain depth to measure the water content of that soil slice. Once the hydraulic equilibrium was reached in each of the two columns, a final moisture profile was taken along the whole column. Three curves were subsequently generated accordingly: (1) the initial moisture profile, (2) the evolution curve of the moisture depletion at that particular depth, and (3) the final moisture profile. All three curves were then inverse analyzed using a MATLAB code over numerical data produced with the van Genuchten-Mualem model. Hereby, a set of values ( α, n, θr and θs) was found for the hydraulic parameters for the soils under research. Additionally, the complete decaying NMR signal could be analyzed through Inverse Laplace Transformation and averaged on the 1/ T2 space. Through measurement of the decay in pure water, the effect on the relaxation caused by the sample could be estimated from the obtained spectra. The migration of the sample-related average with decreasing saturation speaks for a enhancement of the surface relaxation as the soil dries, in

  3. Hydraulic Conductivity Measurements with HTU at Eurajoki, Olkiluoto, Boreholes OL-KR16, 16B, 17, 17B, 18 and 18B, Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H.

    2005-07-01

    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic con- ductivity measurements were carried out in boreholes OL-KR16, 16B, 17, 17 B, 18 and 18B at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during spring-summer 2004. The total lengths of the boreholes are: OL-KR16 170,20 m, OL-KR17 157,13 m and OL-KR18 125,49 m. Corresponding B-holes are around 45 m deep, parallel and adjacent to their 'parent' holes so representing the cased sections of them. The conbined measurable length of the holes is about 453,57 m, of which 429,15 m was covered with 217 standard tests at 2 m packer separation as specified in the research plan. 246 tests were initiated, but some had to be cancelled due to errors or unsuitable control parameters. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the stabilisation, injection or fall-off stage lasted several hours. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  4. Dynamic strain measurement of hydraulic system pipeline using fibre Bragg grating sensors

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2016-04-01

    Full Text Available Fatigue failure is a serious problem in hydraulic piping systems installed in the machinery and equipment working in harsh operational conditions. To alleviate this problem, health monitoring of pipes can be conducted by measuring and analysing vibration-induced strain. Fibre Bragg grating is considered as a promising sensing approach for dynamic load monitoring. In this article, dynamic strain measurements based on fibre Bragg grating sensors for small-bore metal pipes have been investigated. The quasi-distributed strain sensing of fibre Bragg grating sensors is introduced. Two comparison experiments were carried out under vibration and impact loads among the methods of electrical strain gauge, piezoelectric accelerometer and fibre Bragg grating sensor. Experimental results indicate that fibre Bragg grating sensor possesses an outstanding ability to resist electromagnetic interference compared with strain gauge. The natural frequency measurement results, captured by fibre Bragg grating sensor, agree well with the modal analysis results obtained from finite element analysis. In addition, the attached fibre Bragg grating sensor brings a smaller impact on the dynamic characteristics of the measured pipe than the accelerometer due to its small size and lightweight. Fibre Bragg grating sensors have great potential for the quasi-distributed measurement of dynamic strain for the dynamic characteristic research and health monitoring of hydraulic system pipeline.

  5. Bite frequency measured by head pitch movements in grazing experiment

    DEFF Research Database (Denmark)

    Oudshoorn, Frank W.; S. Nadimi, Esmaeil; Jørgensen, Rasmus Nyholm

    2010-01-01

    bite frequency variation related to grass length and grass quality (Pulido & Leaver 2001; Barrett et al. 2003). .   Head movements and bite frequency were registered in spring and autumn in 2009, with 2x10 cows grazing two weeks in two stocking densities.  Head movements were measured by activity...... and  grass offer and  grass growth during the trial by interval harvesting using a Haldrup grass harvester. Cows biting frequency for the same paddock, the same day were found to be cow specific and correlation with milk yield level and barn feed intake was investigated.   Barrett, P.D., McGilloway, D....... ECPLF      2007 Skiathos, Greece. p 111-116 Pulido, R.G. & Leaver, J.D., 2001. Quantifying the influence of sward height, concentrate level and initial      milk yield on the milk production and grazing behaviour of continuously stocked dairy cows. Grass      and Forage Science 56, 57-67.    ...

  6. Measurement of hydraulic conductivity and water retention curves for different methods and prediction of soil physical properties by kriging

    OpenAIRE

    Eurileny Lucas de Almeida

    2013-01-01

    Knowledge of the physical and hydraulic properties of the soil and its spatial dependence is important because it allows you to perform the zoning of the area in plots that receive differentiated management. This work was divided into three chapters whose general objective is to measure the hydraulic conductivity and water retention curve in soil by different methods and by using the Kriging, draw maps of soil physical attributes of the Irrigation Perimeter Baixo AcaraÃ. To obtain the water r...

  7. Calculation of RABBIT and Simulator Worth in the HFIR Hydraulic Tube and Comparison with Measured Values

    Energy Technology Data Exchange (ETDEWEB)

    Slater, CO

    2005-09-08

    To aid in the determinations of reactivity worths for target materials in a proposed High Flux Isotope Reactor (HFIR) target configuration containing two additional hydraulic tubes, the worths of cadmium rabbits within the current hydraulic tube were calculated using a reference model of the HFIR and the MCNP5 computer code. The worths were compared to measured worths for both static and ejection experiments. After accounting for uncertainties in the calculations and the measurements, excellent agreement between the two was obtained. Computational and measurement limitations indicate that accurate estimation of worth is only possible when the worth exceeds 10 cents. Results indicate that MCNP5 and the reactor model can be used to predict reactivity worths of various samples when the expected perturbations are greater than 10 cents. The level of agreement between calculation and experiment indicates that the accuracy of such predictions would be dependent solely on the quality of the nuclear data for the materials to be irradiated. Transients that are approximated by ''piecewise static'' computational models should likewise have an accuracy that is dependent solely on the quality of the nuclear data.

  8. Validation and calibration of HeadCount, a self-report measure for quantifying heading exposure in soccer players.

    Science.gov (United States)

    Catenaccio, E; Caccese, J; Wakschlag, N; Fleysher, R; Kim, N; Kim, M; Buckley, T A; Stewart, W F; Lipton, R B; Kaminski, T; Lipton, M L

    2016-01-01

    The long-term effects of repetitive head impacts due to heading are an area of increasing concern, and exposure must be accurately measured; however, the validity of self-report of cumulative soccer heading is not known. In order to validate HeadCount, a 2-week recall questionnaire, the number of player-reported headers was compared to the number of headers observed by trained raters for a men's and a women's collegiate soccer teams during an entire season of competitive play using Spearman's correlations and intraclass correlation coefficients (ICCs), and calibrated using a generalized estimating equation. The average Spearman's rho was 0.85 for men and 0.79 for women. The average ICC was 0.75 in men and 0.38 in women. The calibration analysis demonstrated that men tend to report heading accurately while women tend to overestimate. HeadCount is a valid instrument for tracking heading behaviour, but may have to be calibrated in women.

  9. Measurement of basic thermal-hydraulic characteristics under the test facility and reactor conditions

    Energy Technology Data Exchange (ETDEWEB)

    Eduard A Boltenko; Victor P Sharov [Elektrogorsk Research and Engineering Center, EREC, Bezimyannaja Street, 6, Elektrogorsk, Moscow Region, 142530 (Russian Federation); Dmitriy E Boltenko [State Scientific Center of Russian Federation IPPE, Bondarenko Square, Obhinsk, Kaluga Region, 249020 (Russian Federation)

    2005-07-01

    Full text of publication follows: The nuclear power of Russia is based on the reactors of two types: water-water - WWER and uranium - graphite channel RBMK. The nuclear power development is possible with performance of the basic condition - level of nuclear power plants (NPP) safety should satisfy the rigid requirements. The calculated proof of NPPs safety made by means of thermal-hydraulic codes of improved estimation, verified on experimental data is the characteristic of this level. The data for code verification can be obtained at the integral facilities simulating a circulation circuit of NPP with the basic units and intended for investigation of circuit behaviour in transient and accident conditions. For verification of mathematical models in transient and accident conditions, development of physically reasonable methods for definition of the various characteristics of two-phase flow the experimental data, as the integrated characteristics of a flow, and data on the local characteristics and structure of a flow is necessary. For safety assurance of NPP it is necessary to monitor and determine the basic thermalhydraulic characteristics of reactor facility (RF). It is possible to refer coolant flow-rate, core input and output water temperature, heat-power. The description of the EREC works in the field completion and adaptation of certain methods with reference to measurements in dynamic modes of test facility conditions and development of methods for measurements of basic thermal-hydraulic characteristics of reactor facilities is presented in the paper. (authors)

  10. New development of hydraulic fracturing technique for in-situ stress measurement at great depth of mines

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In-situ stress measurement using the hydraulic fracturing technique was made at Wanfu Coal Mine in Shandong Province,China.To solve problems caused by great measuring depth and extra thick overburden soil layers in the mine,a series of improved techniques were developed for the traditional hydraulic fracturing technique and equipment to increase their pressure-enduring ability and to ensure safe and flexible removal of the sealing packers with other experimental apparatus.Successful in-situ stress measurement at 37 points within 7 boreholes,which were mostly over 1000 m deep,was completed.Through the measurement,detailed in

  11. Unusually extensive head trauma in a hydraulic elevator accident: post-mortem MSCT findings, autopsy results and scene reconstruction.

    Science.gov (United States)

    Jacobsen, Christina; Schön, Corinna A; Kneubuehl, Beat; Thali, Michael J; Aghayev, Emin

    2008-10-01

    Accidental or intentional falls from a height are a form of blunt trauma and occur frequently in forensic medicine. Reports describing elevator accidents as a small subcategory of falls from heights are rare in the medical literature and no report on injury patterns or scene reconstruction of such an accident was found. A case of an accident in a hydraulic elevator with a man falling 3m was examined using post-mortem multi-slice computed tomography (MSCT) and autopsy. The man suffered an unusually extensive trauma and died at the scene. Post-mortem MSCT examination showed a comminute fracture of the skull, the right femur and the first lumbar vertebra. Severe lacerations of the brain with epidural, subdural and subarachnoidal haemorrhages over both hemispheres were diagnosed. Autopsy confirmed these findings. To reconstruct the accident we used radiological and autopsy results as well as findings at the scene.

  12. Comparing discriminant analysis and neural network for the determination of sex using femur head measurements.

    Science.gov (United States)

    Alunni, Véronique; Jardin, Philippe du; Nogueira, Luisa; Buchet, Luc; Quatrehomme, Gérald

    2015-08-01

    The measurement of the femoral head is usually considered an interesting variable for the sex determination of skeletal remains. To date, there are few published reference measurements of the femoral head in a modern European population for the purpose of sex determination. In this study, 116 femurs from 58 individuals of the South of France (Nice Bone Collection, Nice, France) were studied. Three measurements of the femoral head were taken: the vertical head diameter (VHD), the transversal head diameter (THD) and the head circumference (HC). The results show that: (i) there is no statistical difference between the right and left femurs for each of the three measurements (VHD, THD and HC). Therefore we arbitrarily chose to use the measures from the right femurs (N=58) to pursue our experiments; (ii) the measurements of the femoral head are similar to those of contemporary American populations; (iii) the dimensions of the femoral head place the measurements of the French population somewhere between Germany or Croatia, and Spain; (iv) there is no significant secular trend (in contrast with the femoral neck diameter); (v) the femoral head measurement as a single variable is useful for sex determination: a 96.5% rate of accuracy was obtained using THD and HC measurements with the artificial neural network; and a 94.8% rate of accuracy using VHD, both with the discriminant analysis and the neural network.

  13. Mind the bubbles: achieving stable measurements of maximum hydraulic conductivity through woody plant samples.

    Science.gov (United States)

    Espino, Susana; Schenk, H Jochen

    2011-01-01

    The maximum specific hydraulic conductivity (k(max)) of a plant sample is a measure of the ability of a plants' vascular system to transport water and dissolved nutrients under optimum conditions. Precise measurements of k(max) are needed in comparative studies of hydraulic conductivity, as well as for measuring the formation and repair of xylem embolisms. Unstable measurements of k(max) are a common problem when measuring woody plant samples and it is commonly observed that k(max) declines from initially high values, especially when positive water pressure is used to flush out embolisms. This study was designed to test five hypotheses that could potentially explain declines in k(max) under positive pressure: (i) non-steady-state flow; (ii) swelling of pectin hydrogels in inter-vessel pit membranes; (iii) nucleation and coalescence of bubbles at constrictions in the xylem; (iv) physiological wounding responses; and (v) passive wounding responses, such as clogging of the xylem by debris. Prehydrated woody stems from Laurus nobilis (Lauraceae) and Encelia farinosa (Asteraceae) collected from plants grown in the Fullerton Arboretum in Southern California, were used to test these hypotheses using a xylem embolism meter (XYL'EM). Treatments included simultaneous measurements of stem inflow and outflow, enzyme inhibitors, stem-debarking, low water temperatures, different water degassing techniques, and varied concentrations of calcium, potassium, magnesium, and copper salts in aqueous measurement solutions. Stable measurements of k(max) were observed at concentrations of calcium, potassium, and magnesium salts high enough to suppress bubble coalescence, as well as with deionized water that was degassed using a membrane contactor under strong vacuum. Bubble formation and coalescence under positive pressure in the xylem therefore appear to be the main cause for declining k(max) values. Our findings suggest that degassing of water is essential for achieving stable and

  14. Spatial variability in streambed hydraulic conductivity of contrasting stream morphologies

    DEFF Research Database (Denmark)

    Sebök, Éva; Calvache, Carlos Duque; Engesgaard, Peter Knudegaard;

    2015-01-01

    Streambed hydraulic conductivity is one of the main factors controlling variability in surface water-groundwater interactions, but only few studies aim at quantifying its spatial and temporal variability in different stream morphologies. Streambed horizontal hydraulic conductivities (Kh) were...... therefore determined from in-stream slug tests, vertical hydraulic conductivities (Kv) were calculated with in-stream permeameter tests and hydraulic heads were measured to obtain vertical head gradients at eight transects, each comprising five test locations, in a groundwater-dominated stream. Seasonal...... small-scale measurements were taken in December 2011 and August 2012, both in a straight stream channel with homogeneous elevation and downstream of a channel meander with heterogeneous elevation. All streambed attributes showed large spatial variability. Kh values were the highest at the depositional...

  15. Regression analysis between body and head measurements of Chinese alligators (Alligator sinensis in the captive population

    Directory of Open Access Journals (Sweden)

    Wu, X. B.

    2006-06-01

    Full Text Available Four body-size and fourteen head-size measurements were taken from each Chinese alligator (Alligator sinensis according to the measurements adapted from Verdade. Regression equations between body-size and head-size variables were presented to predict body size from head dimension. The coefficients of determination of captive animals concerning body- and head-size variables can be considered extremely high, which means most of the head-size variables studied can be useful for predicting body length. The result of multivariate allometric analysis indicated that the head elongates as in most other species of crocodilians. The allometric coefficients of snout length (SL and lower ramus (LM were greater than those of other variables of head, which was considered to be possibly correlated to fights and prey. On the contrary, allometric coefficients for the variables of obita (OW, OL and postorbital cranial roof (LCR, were lower than those of other variables.

  16. Moving distance measurement for hydraulic support based on fruit fly optimization algorithm

    Science.gov (United States)

    Wang, Jiabiao; Wang, Zhongbin; Xu, Jing; Tan, Chao; Si, Lei

    2017-01-01

    Due to the inaccurate and unreliable moving distance measurement of the hydraulic support in mines, a method based on the random circle detection (RCD) algorithm and the fruit fly optimization algorithm (FOA) is proposed. According to the changing center and radium of the circle on the support, the relative position of adjacent supports is acquired by the camera. The noise of the collected image is moved, and the edge feature is protected using a bilateral filter. A local adaptive threshold algorithm is used for binary processing of the image. Then, RCD is used to detect the contour, which is similar to the circle. A method to detect the circle based on FOA is used to accurately detect the circle. Subsequently, the relative distance is calculated according to the change of the circle. Finally, the accuracy and reliability of the proposed method are verified though the experiment.

  17. Variations in hydraulic conductivity with scale of measurement during aquifer tests in heterogeneous, porous carbonate rocks

    Science.gov (United States)

    Schulze-Makuch, Dirk; Cherkauer, Douglas S.

    Previous studies have shown that hydraulic conductivity of an aquifer seems to increase as the portion of the aquifer tested increases. To date, such studies have all relied on different methods to determine hydraulic conductivity at each scale of interest, which raises the possibility that the observed increase in hydraulic conductivity is due to the measurement method, not to the scale. This study analyzes hydraulic conductivity with respect to scale during individual aquifer tests in porous, heterogeneous carbonate rocks in southeastern Wisconsin, USA. Results from this study indicate that hydraulic conductivity generally increases during an individual test as the volume of aquifer impacted increases, and the rate of this increase is the same as the rate of increase determined by using different measurement methods. Thus, scale dependence of hydraulic conductivity during single tests does not depend on the method of measurement. This conclusion is supported by 22 of 26 aquifer tests conducted in porous-flow-dominated carbonate units within the aquifer. Instead, scale dependency is probably caused by heterogeneities within the aquifer, a conclusion supported by digital simulation. All of the observed types of hydraulic-conductivity variations with scale during individual aquifer tests can be explained by a conceptual model of a simple heterogeneous aquifer composed of high-conductivity zones within a low-conductivity matrix. Résumé Certaines études ont montré que la conductivité hydraulique d'un aquifère semble augmenter en même temps que la partie testée de l'aquifère s'étend. Jusqu'à présent, ces études ont toutes reposé sur des méthodes de détermination de la conductivité hydraulique différentes pour chaque niveau d'échelle, ce qui a conduit à penser que l'augmentation observée de la conductivité hydraulique pouvait être due aux méthodes de mesure et non à l'effet d'échelle. Cette étude analyse la conductivité hydraulique par

  18. The reliability of head film measurements. 3. Tracing superimposition.

    Science.gov (United States)

    Baumrind, S; Miller, D; Molthen, R

    1976-12-01

    The superimposition of tracings from lateral skull x-ray films taken at different timepoints is an important method for assessing developmental and treatment changes through time. The usefulness of the data derived is, however, limited by the fact that the physical act of superimposing tracings is performed with some error. The magnitudes of error for superimpositions on different "planes" have not been amenable to quantitation by previously available methods. Using newly developed computer-aided techniques, we have been able to quantitate both the primary errors of tracing superimposition and the associated secondary landmark displacements for four conventionally employed anatomic reference "planes". For each reference "plane," twenty-five independent film pairs were examined independently by each of four judges. Therefore, 100 acts of tracing superimposition were available for each reference "plane." Output data are presented which appear to support the conclusion that measurement errors in tracing superimposition are a consequential factor affecting the confidence which should be placed in head film comparisons, particularly with regard to individual cases. Some consequences of this conclusion with respect to growth prediction and to the evaluation of treatment effects are considered.

  19. Measuring How the Head of Department Measures Up: Development of an Evaluation Framework for the Head of Department Role

    Science.gov (United States)

    London, Chad

    2011-01-01

    The head of department position has been an integral role in the organisational structure of colleges and universities for over a hundred years. Recently, many institutions of higher education have called on department heads to provide advancing quality management and leadership to academic units in response to an increasingly complex and…

  20. Measuring How the Head of Department Measures Up: Development of an Evaluation Framework for the Head of Department Role

    Science.gov (United States)

    London, Chad

    2011-01-01

    The head of department position has been an integral role in the organisational structure of colleges and universities for over a hundred years. Recently, many institutions of higher education have called on department heads to provide advancing quality management and leadership to academic units in response to an increasingly complex and…

  1. Spectral induced polarization measurements for predicting the hydraulic conductivity in sandy aquifers

    Directory of Open Access Journals (Sweden)

    M. Attwa

    2013-10-01

    Full Text Available Field and laboratory spectral induced polarization (SIP measurements are integrated to characterize the hydrogeological conditions at the Schillerslage test site in Germany. The phase images are capable of monitoring thin peat layers within the sandy aquifers. However, the field results show limitations of decreasing resolution with depth. In comparison with the field inversion results, the SIP laboratory measurements show a certain shift in SIP response due to different compaction and sorting of the samples. The SIP data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K. In particular, two significant but weak correlations between individual real resistivities (ρ' and relaxation times (τ, based on a Debye decomposition (DD model, with measured K are found for the upper groundwater aquifer. The maximum relaxation time (τmax and logarithmically weighted average relaxation time (τlw show a better relation with K values than the median value τ50. A combined power law relation between individual ρ' and τ with K is developed with an expression of A · (ρ'B · (τlwC, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second. Results show good correlation with the measured K indicating that the derived relationship is superior to single phase angle models as Börner or Slater models.

  2. Validation of a wireless head acceleration measurement system for use in soccer play.

    Science.gov (United States)

    Hanlon, Erin; Bir, Cynthia

    2010-11-01

    Soccer heading has been studied previously with conflicting results. One major issue is the lack of knowledge regarding what actually occurs biomechanically during soccer heading impacts. The purpose of the current study is to validate a wireless head acceleration measurement system, head impact telemetry system (HITS) that can be used to collect head accelerations during soccer play. The HIT system was fitted to a Hybrid III (HIII) head form that was instrumented with a 3-2-2-2 accelerometer setup. Fifteen impact conditions were tested to simulate impacts commonly experienced during soccer play. Linear and angular acceleration were calculated for both systems and compared. Root mean square (RMS) error and cross correlations were also calculated and compared for both systems. Cross correlation values were very strong with r = .95 ± 0.02 for ball to head forehead impacts and r = .96 ± 0.02 for head to head forehead impacts. The systems showed a strong relationship when comparing RMS error, linear head acceleration, angular head acceleration, and the cross correlation values.

  3. In-situ stress from hydraulic fracture measurements in G Tunnel, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.; Vollendorf, W. C.; Warren, W. E.

    1981-04-01

    Hydraulic fracture work in G Tunnel, Nevada Test Site, performed to obtain the in-situ stress state is discussed. Field equipment and procedures are described; analysis is developed to relate the hydraulic fracture pressures to the in-situ stress state. Pressure data are analyzed to provide estimates of the stress state at a number of locations in the tunnel complex. A unique feature of the work is the mineback - a mining process in which the rock is cut away to reveal the actual plane of the fracture. Advantages, limitations, and problem areas associated with extracting in-situ stress fields from hydraulic fracture pressure records are discussed in detail.

  4. A falling-head procedure for the measurement of filter media sphericity

    African Journals Online (AJOL)

    A falling-head procedure for the measurement of filter media sphericity. ... Filter media sphericity is normally determined experimentally in a laboratory filtration column. The pressure drop is measured across ... Article Metrics. Metrics Loading .

  5. Land-use effects on flood generation – considering soil hydraulic measurements in modelling

    Directory of Open Access Journals (Sweden)

    A. Münch

    2009-08-01

    Full Text Available The investigation in the catchment of the Mulde (51°0'55" N, 13°15'54" E Saxony, Germany researches the effect of afforestation measures on the soil hydraulic properties. The concept of a "false chronosequence" was used to quantify the time-dependent dynamical character of the forest impact. Four adjacent plots were identified at a test location with comparable pedological start conditions and a set of tree stands of different age: (1 arable field (initial state; (2 6-year-old afforestation; (3 50-year-old afforestation; (4 ancient natural forest ("target" stocking. Water retention curves and unsaturated conductivities were analysed in the lab. In the field, the undisturbed infiltration capacities were measured quantitatively (hood infiltrometer and qualitatively (brilliant blue tracer. Pronounced differences between all 4 plots were detected. The afforestation causes an increased infiltration and soil water retention potential. Especially the topsoil layers showed a distinct increase in conductivity and portion of coarse/middle pores. The influence of these changes on rainfall-runoff calculations at the test location was analysed in this study.

  6. Measurement of flow diverter hydraulic resistance to model flow modification in and around intracranial aneurysms.

    Science.gov (United States)

    Ugron, Adám; Szikora, István; Paál, György

    2014-06-01

    Flow diverters (FDs) have been successfully applied in the recent decade to the treatment of intracranial aneurysms by impairing the communication between the flows in the parent artery and the aneurysm and, thus, the blood within the aneurysm sac. It would be desirable to have a simple and accurate computational method to follow the changes in the peri- and intraaneurysmal flow caused by the presence of FDs. The detailed flow simulation around the intricate wire structure of the FDs has three disadvantages: need for high amount of computational resources and highly skilled professionals to prepare the computational grid, and also the lack of validation that makes the invested effort questionable. In this paper, we propose a porous layer method to model the hydraulic resistance (HR) of one or several layers of the FDs. The basis of this proposal is twofold: first, from an application point of view, the only interesting parameter regarding the function of the FD is its HR; second, we have developed a method to measure the HR with a simple apparatus. We present the results of these measurements and demonstrate their utility in numerical simulations of patient-specific aneurysm simulations.

  7. Spectral induced polarization measurements for environmental purposes and predicting the hydraulic conductivity in sandy aquifers

    Directory of Open Access Journals (Sweden)

    M. Attwa

    2013-04-01

    Full Text Available Low-frequency field and laboratory induced polarization measurements are carried out to characterize the hydrogeological conditions at Schillerslage test site in Germany. The laboratory spectral induced polarization (SIP data are analyzed to derive an empirical relationship for predicting the hydraulic conductivity (K in the field scale. On the other hand, the results from SIP sounding and profiling field data indicate that the method identifies the lithological layers with sufficient resolution to achieve our objectives. Two main Quaternary groundwater aquifers separated by a till layer can be well differentiated. Furthermore, the phase images are also capable of monitoring thin peat layers within the sandy groundwater aquifer. However, the field results show limitations of decreasing resolution with depth and/or low data coverage. Similarly, the SIP laboratory results show a certain shift in SIP response due to different compaction and sorting of the samples. The overall results obtained show that the integration of field and laboratory SIP measurements is an efficient tool to avoid a hydrogeological misinterpretation. In particular, two significant but weak correlations between individual real resistivities (ρ' and relaxation times (τ, based on a Debye decomposition (DD model, with measured K are found for the upper groundwater aquifer. While the maximum relaxation time (τmax and logarithmically weighted average relaxation time (τlw show a better relation with K values than the median value τ50, however, the single relationships are weak. A combined power law relation between individual ρ' and/or τ with K is developed with an expression of A · (ρ'B · (τlwC, where A, B and C are determined using a least-squares fit between the measured and predicted K. The suggested approach with the calculated coefficients of the first aquifer is applied for the second one. The results indicate a good correlation with the measured K and prove to be

  8. May We Identify The Spatial Variability of Soil Hydraulic Properties Based On Measurements With "spatial Tdr"? A) Model Study

    Science.gov (United States)

    Zehe, E.; Becker, R.; Schädel, W.

    A dynamic system left without external disturbances, will always tend to a stable equilibrium state that is consistent with the internal physics. For natural soils such an equilibrium state is reached when the gradients of the total hydraulic potential tend to zero. This statement is still valid for heterogeneous soils, because the hydraulic po- tential is an intensive state variable and therefore continuous at discontinuities of the pore space. In contrary the soil water content is as an extensive property discontinu- ous at discontinuities of the pore space. Hence, a small scale soil moisture pattern that persists if the soil state tends to hydraulic equilibrium, reflects the lateral small scale variability of the pore space. The objectives of our study are to show a) whether and how we could use TDR observations to identify the small scale variability of the pore space. For that purpose we analyse artificial TDR measurements, taken from physi- cally based simulations of soil water dynamics in heterogeneous media. b) We want to introduce a new TDR technology which we call "Spatial TDR", that is suitable for that purposes. To produce the artificial TDR-datasets we generate random fields of soil porosity and saturated hydraulic conductivity with different statistical properties based on field data in a Luvisol and simulate artificial water dynamics in this model soil based on Richards-equation. Within this model soil we define several hypothetical "Spatial TDR" clusters, that differ in the lateral spacing and the number of the probes, in the temporal resolution of the hypothetical measurements and in the assumed mea- surement accuracy. If the model soil approaches hydraulic equilibrium, the remaining soil moisture pattern will be dominated by the statistical properties of the porosity. In contrary the variability of the hydraulic conductivity will dominate the soil moisture patterns during infiltration events. The hypothetical Spatial TDR measurements within the

  9. Three-dimensional surface scanners compared with standard anthropometric measurements for head shape.

    Science.gov (United States)

    Beaumont, Caroline A A; Knoops, Paul G M; Borghi, Alessandro; Jeelani, N U Owase; Koudstaal, Maarten J; Schievano, Silvia; Dunaway, David J; Rodriguez-Florez, Naiara

    2017-06-01

    Three-dimensional (3D) surface imaging devices designed to capture and quantify craniofacial surface morphology are becoming more common in clinical environments. Such scanners overcome the limitations of two-dimensional photographs while avoiding the ionizing radiation of computed tomography. The purpose of this study was to compare standard anthropometric cranial measurements with measurements taken from images acquired with 3D surface scanners. Two 3D scanners of different cost were used to acquire head shape data from thirteen adult volunteers: M4D scan and Structure Sensor. Head circumference and cephalic index were measured directly on the patients as well as on 3D scans acquired with the two scanners. To compare head volume measurements with a gold standard, magnetic resonance imaging scans were used. Repeatability and accuracy of both devices were evaluated. Intra-rater repeatability for both scanners was excellent (intraclass correlation coefficients > 0.99, p < 0.001). Direct and digital measures of head circumference, cephalic index and head volume were strongly correlated (0.85 < r < 0.91, p < 0.001). Compared to direct measurements, accuracy was highest for M4D scan. Both 3D scanners provide reproducible data of head circumference, cephalic index and head volume and show a strong correlation with traditional measurements. However, care must be taken when using absolute values. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  10. Non-linear friction in reciprocating hydraulic rod seals: Simulation and measurement

    Science.gov (United States)

    Bullock, A. K.; Tilley, D. G.; Johnston, D. N.; Bowen, C. R.; Keogh, P. S.

    2009-08-01

    Non-linear seal friction can impede the performance of hydraulic actuation systems designed for high precision positioning with favourable dynamic response. Methods for predicting seal friction are required to help develop sealing systems for this type of application. Recent simulation techniques have claimed progress, although have yet to be validated experimentally. A conventional reciprocating rod seal is analysed using established elastohydrodynamic theory and the mixed lubrication Greenwood-Williamson-average Reynolds model. A test rig was used to assess the accuracy of the simulation results for both instroke and outstroke. Inverse hydrodynamic theory is shown to predict a U0.5 power law between rod speed and friction. Comparison with experimental data shows the theory to be qualitatively inaccurate and to predict friction levels an order of magnitude lower than those measured. It was not possible to model the regions very close to the inlet and outlet due to the high pressure gradients at the edges of the contact. The mixed lubrication model produces friction levels within the correct order of magnitude, although incorrectly predicts higher friction during instroke than outstroke. Previous experiments have reported higher friction during instroke than outstroke for rectangular seals, suggesting that the mixed lubrication model used could possibly be suitable for symmetric seals, although not for seal tribology in general.

  11. Evolution of the sensor fish device for measuring physical conditions in sever hydraulic environments

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Duncan, J. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2003-03-01

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new “fish-friendly” turbines, and spillway designs and operations, Pacific Northwest National Laboratory (PNNL) scientists have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. This report discusses the development and field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River, which have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  12. Evolution of the Sensor Fish Device for Measuring Physical Conditions in Severe Hydraulic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J.; Duncan, Joanne P.

    2003-02-28

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new ''fish-friendly'' turbines, and spillway designs and operations, scientists at the Pacific Northwest National Laboratory (PNNL) have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. The Sensor Fish was developed with the support of the U.S. Department of Energy's Advanced Hydropower Turbine System program. Field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  13. 超低水头水轮机流动数值模拟及水力性能研究%Research on Flow Numerical Simulation and Hydraulic Performance of Ultra Low-head Water Turbine

    Institute of Scientific and Technical Information of China (English)

    肖惠民

    2013-01-01

    In order to develop economical and practical ultra low-head turbine (the net head low than 5m),the internal flow of ultra low-head water turbine with utilization of water and wave energy for generation is simulated by using computational fluid dynamics technology.The efficiency of the entire turbine is predicted and the hydraulic characteristics of the ultra low-head water turbine are analyzed.In the 1.5-5m head range,numerical simulations show that the ultra low-head water turbine has relatively high and slowly changing efficiency,and its output power basically depends on the head.%为开发经济实用超低水头(净水头低于5 m)的水轮机,基于流体动力学理论对可应用于水能、波浪能发电的某超低水头水轮机进行了内部流动数值模拟及性能预测,并分析了水头和转速特性.结果表明,在1.5~5.0m水头范围内,水轮机效率较高,变化平稳,输出功率主要取决于水头.

  14. Simulating soil-water movement through loess-veneered landscapes using nonconsilient saturated hydraulic conductivity measurements

    Science.gov (United States)

    Williamson, Tanja N.; Lee, Brad D.; Schoeneberger, Philip J.; McCauley, W. M.; Indorante, Samuel J.; Owens, Phillip R.

    2014-01-01

    Soil Survey Geographic Database (SSURGO) data are available for the entire United States, so are incorporated in many regional and national models of hydrology and environmental management. However, SSURGO does not provide an understanding of spatial variability and only includes saturated hydraulic conductivity (Ksat) values estimated from particle size analysis (PSA). This study showed model sensitivity to the substitution of SSURGO data with locally described soil properties or alternate methods of measuring Ksat. Incorporation of these different soil data sets significantly changed the results of hydrologic modeling as a consequence of the amount of space available to store soil water and how this soil water is moved downslope. Locally described soil profiles indicated a difference in Ksat when measured in the field vs. being estimated from PSA. This, in turn, caused a difference in which soil layers were incorporated in the hydrologic simulations using TOPMODEL, ultimately affecting how soil water storage was simulated. Simulations of free-flowing soil water, the amount of water traveling through pores too large to retain water against gravity, were compared with field observations of water in wells at five slope positions along a catena. Comparison of the simulated data with the observed data showed that the ability to model the range of conditions observed in the field varied as a function of three soil data sets (SSURGO and local field descriptions using PSA-derived Ksat or field-measured Ksat) and that comparison of absolute values of soil water storage are not valid if different characterizations of soil properties are used.

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

    Science.gov (United States)

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

    2014-05-01

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

  16. Estimation of soil hydraulic parameters by integrated hydrogeophysical inversion of time-lapse GPR data measured at Selhausen, Germany

    KAUST Repository

    Jadoon, Khan

    2012-06-01

    We present an integrated hydrogeophysical inversion approach that uses time-lapse off-ground ground-penetrating radar (GPR) data to estimate soil hydraulic parameters, and apply it to a dataset collected in the field. Off-ground GPR data are mainly sensitive to the near-surface water content profile and dynamics, and are thus related to soil hydraulic parameters, such as the parameters of the hydraulic conductivity and water retention functions. The hydrological simulator HYDRUS 1-D was used with a two-layer single- and dual-porosity model. To monitor the soil water content dynamics, time-lapse GPR and time domain reflectometry (TDR) measurements were performed, whereby only GPR data was used in the inversion. The dual porosity model provided better results compared to the single porosity model for describing the soil water dynamics, which is supported by field observations of macropores. Furthermore, the GPR-derived water content profiles reconstructed from the integrated hydrogeophysical inversion were in good agreement with TDR observations. These results suggest that the proposed method is promising for non-invasive characterization of the shallow subsurface hydraulic properties and monitoring water dynamics at the field scale.

  17. Relax and refill: xylem rehydration prior to hydraulic measurements favours embolism repair in stems and generates artificially low PLC values.

    Science.gov (United States)

    Trifilò, Patrizia; Raimondo, Fabio; Lo Gullo, Maria A; Barbera, Piera M; Salleo, Sebastiano; Nardini, Andrea

    2014-11-01

    Diurnal changes in percentage loss of hydraulic conductivity (PLC), with recorded values being higher at midday than on the following morning, have been interpreted as evidence for the occurrence of cycles of xylem conduits' embolism and repair. Recent reports have suggested that diurnal PLC changes might arise as a consequence of an experimental artefact, that is, air entry into xylem conduits upon cutting stems, even if under water, while under substantial tension generated by transpiration. Rehydration procedures prior to hydraulic measurements have been recommended to avoid this artefact. In the present study, we show that xylem rehydration prior to hydraulic measurements might favour xylem refilling and embolism repair, thus leading to PLC values erroneously lower than those actually experienced by transpiring plants. When xylem tension relaxation procedures were performed on stems where refilling mechanisms had been previously inhibited by mechanical (girdling) or chemical (orthovanadate) treatment, PLC values measured in stems cut under native tension were the same as those measured after sample rehydration/relaxation. Our data call for renewed attention to the procedures of sample collection in the field and transport to the laboratory, and suggest that girdling might be a recommendable treatment prior to sample collection for PLC measurements.

  18. Influence of Air Discontinuity and Wall Effects on the Measurements of Hydraulic Parameters Under Dynamic Conditions

    Science.gov (United States)

    Looms, M. C.; Jensen, K. H.; Wildenschild, D.; Christensen, B. S.; Gudbjerg, J.

    2003-12-01

    Both dynamic (one-step) and semi-static (syringe pump) outflow experiments were carried out in the lab to test whether the resulting retention characteristics differed according to experiment type. Three sands of varying uniformity and coarseness were packed in a cylindrical sample holder. Compressed air was used to control the air phase pressure, while water was allowed to drain at atmospheric pressure from the outlet at the bottom of the sample. During the outflow experiments the capillary pressure was measured within the sample holder using a tensiometer connected to a pressure transducer. A medical CT-scanner was used to visualize and quantify the outflow patterns within the sand matrix during selected outflow experiments. Positive vertical shifts in capillary pressure during dynamic experiments were found in all three sand types at saturations close to porosity. The size and shape of the shifts corresponded with the dynamic effects found in previous work on the topic. Furthermore, the shifts were slightly greater in the coarsest and most uniform sand type. Numerical simulations of the one-step experiments using HYDRUS1D and T2VOC showed, however, that one of the basic assumptions when calculating the capillary pressure was most likely violated. The air phase could not be considered to be continuous at all times, and assuming this to be the case would result in positive shifts of the retention curves when running T2VOC. The results of using the CT-scanner showed the importance of achieving a homogeneous packing, since the investigated sand packing turned out to have an area at the edge of the sample holder with a higher porosity. This caused the edge to control the initial drainage. Therefore, the data collected at high saturations could not be expected to adequately describe the hydraulic properties of the inner sand. We also found that the time at which the inner sand commenced drainage coincided with a jump in capillary pressure for the resulting measured

  19. Measuring the initial earth pressure of granite using hydraulic fracturing test; Goseong and Yuseong areas

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Won, Kyung Sik [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-02-01

    This report provides the initial earth pressure of granitic rocks obtained from Deep Core Drilling Program which is carried out as part of the assessment of deep geological environmental condition. These data are obtained by hydraulic fracturing test in three boreholes drilled up to 350{approx}500 m depth at the Yuseong and Goseong sites. These sites were selected based on the result of preliminary site evaluation study. The boreholes are NX-size (76 mm) and vertical. The procedure of hydraulic fracturing test is as follows: - Selecting the testing positions by preliminary investigation using BHTV logging. - Performing the hydraulic fracturing test at each selected position with depth.- Estimating the shut-in pressure by the bilinear pressure-decay-rate method. - Estimating the fracture reopening pressure from the pressure-time curves.- Estimating the horizontal principal stresses and the direction of principal stresses. 65 refs., 39 figs., 12 tabs. (Author)

  20. The study on measures to improve the reliability of the hydraulic systems of shearers

    Institute of Scientific and Technical Information of China (English)

    袁辉; 徐龙江; 田大宝; 赵燕玲

    2001-01-01

    The authors indicate that the failure of hydraulic systems of shearers can drop greatly, its' reliability and service life can be increased by the use of a field oil contamination analyser and filter device to control the oil contamination of the hydraulic systems of shearers. Experimental provement of silting-theory contamination analyser are carried out. The filter effect of portable hydraulic driving oil-filter model YLJ-21 is examinationed in laboratory and field experiment. From January to August 1992, on-site experimental research using a silting-theory contamination analyser and oil-filter model YLJ-21 to control the oil contamination was carried out in the Datong Coat Mining Bureau.

  1. Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound (Head and Spinal)

    Science.gov (United States)

    Hargens, Alan R.

    1999-01-01

    Prevention of secondary brain injuries following head trauma can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop device, which was developed and patented by consultants Drs. Yost and Cantrell, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year two studies included whole body head-up and head-down tilting effects on intracranial compliance and pressure in six healthy volunteers.

  2. Leg blood flow measurements using venous occlusion plethysmography during head-up tilt.

    NARCIS (Netherlands)

    Kooijman, M.; Poelkens, F.; Rongen, G.A.; Smits, P.; Hopman, M.T.E.

    2007-01-01

    We tested whether venous occlusion plethysmography (VOP) is an appropriate method to measure calf blood flow (CBF) during head-up tilt (HUT). CBF measured with VOP was compared with superficial femoral artery blood flow as measured by Doppler ultrasound during incremental tilt angles. Measurements o

  3. Test-retest reliability of handgrip strength measurement using a hydraulic hand dynamometer in patients with cervical radiculopathy.

    Science.gov (United States)

    Savva, Christos; Giakas, Giannis; Efstathiou, Michalis; Karagiannis, Christos

    2014-01-01

    The purpose of this study was to evaluate the test-retest reliability of handgrip strength measurement using a hydraulic hand dynamometer in patients with cervical radiculopathy (CR). A convenience sample of 19 participants (14 men and 5 women; mean ± SD age, 50.5 ± 12 years) with CR was measured using a Jamar hydraulic hand dynamometer by the same rater on 2 different testing sessions with an interval of 7 days between sessions. Data collection procedures followed standardized grip strength testing guidelines established by the American Society of Hand Therapists. During the repeated measures, patients were advised to rest their upper limb in the standardized arm position and encouraged to exert 3 maximum gripping efforts. The mean value of the 3 efforts (measured in kilogram force [Kgf]) was used for data analysis. The intraclass correlation coefficient, SEM, and the Bland-Altman plot were used to estimate test-retest reliability and measurement precision. Grip strength measurement in CR demonstrated an intraclass correlation coefficient of 0.976, suggesting excellent test-retest reliability. The small SEM in both testing sessions (SEM1, 2.41 Kgf; SEM2, 2.51 Kgf) as well as the narrow width of the 95% limits of agreements (95% limits of agreement, -4.9 to 4.4 Kgf) in the Bland-Altman plot reflected precise measurements of grip strength in both occasions. Excellent test-retest reliability for grip strength measurement was measured in patients with CR, demonstrating that a hydraulic hand dynamometer could be used as an outcome measure for these patients. Copyright © 2014 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  4. Outcomes measurement in patients with head and neck cancer.

    Science.gov (United States)

    Gourin, Christine G

    2014-03-01

    Outcomes research is defined as clinical and population-based research that investigates the results of healthcare practices or interventions through the filter of the benefit to the patient and other stakeholders. Outcomes research is an increasingly important field or research, because of the pressing need for evidence-based information that can be used to make better informed health and healthcare decisions, and define desired health care practices in the current era of healthcare reform. This article will review the head and neck cancer (HNCA) outcomes literature published in the past year, with a focus on studies evaluating treatment and survival, short-term and long-term complications, and quality of life (QOL).

  5. Control of dense collagen gel scaffolds for tissue engineering through measurement and modelling of hydraulic permeability

    Science.gov (United States)

    Serpooshan, Vahid

    Among various natural biopolymers, type I collagen gels have demonstrated the highest potential as biomimetic scaffolds for tissue engineering (TE). However, the successful application of collagen gels requires a greater understanding of the relationship between their microstructure and physical-mechanical properties. Therefore, a precise method to modulate collagen gel microstructure in order to attain optimal scaffold properties for diverse biomedical applications is necessary. This dissertation describes a new approach to produce collagen gels with defined microstructures, quantified by hydraulic permeability ( k), in order to optimize scaffold properties for TE applications. It was hypothesized that the measurement of k can be used to study the role of microstructure in collagen gel properties, as well as cell function and cell-scaffold interactions. Applying increasing levels of plastic compression (PC) to the highly hydrated collagen gels resulted in an increase in collagen fibrillar density, reduced Happel model derived k values, increased gel stiffness, promoted MSC metabolic activity, osteogenic differentiation, and mineral deposition, while cell-induced gel contraction diminished. Thus, collagen gels with lower k and higher stiffness values exhibited greater potential for bone tissue engineering. Correlating between collagen gel microstructure, k, and fibroblast function within collagen gels indicated that increasing the level of PC yielded a reduction in pore size and an increase in fibril bundle diameter. Decrease in k values resulted in a decrease in gel contraction and an increase in cell metabolic activity. An increase in cell density accelerated contraction. Therefore, fibroblast function within collagen gels can be optimised by a balance between the microstructure, k, and cell seeding density. Developing a micromechanical model to measure experimental k of collagen gels during confined compression revealed the formation of a dense collagen lamella

  6. Water Treatment Technology - Hydraulics.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  7. PREDICTION OF STATURE BY THE MEASUREMENT OF HEAD LE NGTH IN POPULATION OF RAJASTHAN

    Directory of Open Access Journals (Sweden)

    Santosh

    2013-04-01

    Full Text Available ABSTRACT: BACKGROUND: Estimation of stature has a significant importance in the field of forensic anthropometry for the identification of an individual. AIMS: Study was carried out to assess and correlate head length and the stature an d to predict the stature of an individual by head length using regression analysis. MATERIALS & METHODS: Total 300 (150 males and 150 females medical students of S.M.S medical college, Jaipur (Rajasthan were selected. Head length and height of the individual were measured. RESULTS: Correlation coefficient between height & head length were r=0.941 for Male & r= 0.8 5 for Female suggestive of strong positive correlation. Regression equations were derived to c alculate height of unknown individual from head length. CONCLUSION: Present study has established definite correlation between stature and head length. If either of the measurement (tota l height or head length is known, the other can be calculated. It will help in medico-legal case s in establishing identity of an individual when only some remains of the body are found as in mass disasters, bomb explosions, accidents etc

  8. Binaural loudness for artificial-head measurements in directional sound fields

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Ellermeier, Wolfgang

    2008-01-01

    The effect of the sound incidence angle on loudness was investigated for fifteen listeners who matched the loudness of sounds coming from five different incidence angles in the horizontal plane to that of the same sound with frontal incidence. The stimuli were presented via binaural synthesis...... by using head-related transfer functions measured for an artificial head. The results, which exhibited marked individual differences, show that loudness depends on the direction from which a sound reaches the listener. The average results suggest a relatively simple rule for combining the two signals...... at the ears of an artificial head for binaural loudness predictions....

  9. Complexity and measurement of complex degree of gas gush in heading faces of coal mine

    Energy Technology Data Exchange (ETDEWEB)

    He, Li-wen; Shi, Shi-liang; Song, Yi; Liu, Ying [Central Southern University, Changsha (China). School of ResourceS and Safety Engineering

    2008-05-15

    Rationality about ventilation in the working face of a coal mine, the validity of measures to prevent and stop gas disasters and security of high production are directly influenced by the gas gushing in the heading faces of a coal mine. Therefore, the time series of gas gushing in the heading faces was calculated and analyzed by applying the relation dimension. The result proves that the gas gushing system of the heading faces is a nonlinear chaos system with a complex structure and chaotic attractors and 11 unattached variables or an 11-step dynamic equation is needed to describe the system. 8 refs., 3 figs.

  10. Effect of Sound Source Scattering on Measurement of Near-Field Head-Related Transfer Functions

    Institute of Scientific and Technical Information of China (English)

    YU Guang-Zheng; XIE Bo-Sun; RAO Dan

    2008-01-01

    @@ A simple spherical head and pulsating spherical sound source model are proposed to investigate the effect of multiple scattering between the head and the sound source on near-field head-related transfer function (HRTF) measurement. Multipole expansion method is used to calculate HRTFs of the model, then the relationships among the magnitude error of HRTF with frequency, source direction, source size, and the distance between the head centre and the sound source are analysed. The results show that to ensure the magnitude error of HRTF within 1.0 dB up to 20 kHz, for source distance not less than 0.15m or 0.20 m, the radius of the sound source should not exceed 0.03 m or 0.05 m, respectively. The conclusion suggests an appropriate size of sound source in near-field HRTF measurement.

  11. Trismus following different treatment modalities for head and neck cancer: a systematic review of subjective measures

    OpenAIRE

    Loh, Sook Y.; Mcleod, Robert W. J.; Elhassan, Hassan A.

    2017-01-01

    The aim of this review was to compare systematically the subjective measure of trismus between different interventions to treat head and neck cancer, particularly those of the oropharynx. Using The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) Guidelines, Six databases were searched for the text using various terms which include ?oropharyngeal/head and neck cancer?, ?trismus/mouth opening? and the various treatment modalities. Included in the review were clinical ...

  12. A Probe Head for Simultaneous Measurements of Electrostatic and Magnetic Fluctuations in ASDEX Upgrade Edge Plasma

    DEFF Research Database (Denmark)

    Schrittwieser, R W; Ionita, C; Vianello, N

    2010-01-01

    For ASDEX Upgrade (AUG) a new probe head was developed for simultaneous measurements of electric and magnetic fluctuations in the edge plasma region. The probe head consists of a cylindrical graphite case. On the front side six graphite pins are mounted. With this arrangement the poloidal and rad...... is inserted up to three times for 100 ms each by the midplane manipulator into the scrape-off layer. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

  13. Effect of Head Position on Facial Soft Tissue Depth Measurements Obtained Using Computed Tomography.

    Science.gov (United States)

    Caple, Jodi M; Stephan, Carl N; Gregory, Laura S; MacGregor, Donna M

    2016-01-01

    Facial soft tissue depth (FSTD) studies employing clinical computed tomography (CT) data frequently rely on depth measurements from raw 2D orthoslices. However, the position of each patient's head was not standardized in this method, potentially decreasing measurement reliability and accuracy. This study measured FSTDs along the original orthoslice plane and compared these measurements to those standardized by the Frankfurt horizontal (FH). Subadult cranial CT scans (n = 115) were used to measure FSTDs at 18 landmarks. Significant differences were observed between the methods at eight of these landmarks (p < 0.05), demonstrating that high-quality data are not generated simply by employing modern imaging modalities such as CT. Proper technique is crucial to useful results, and maintaining control over head position during FSTD data collection is important. This is easily and most readily achieved in CT techniques by rotating the head to the FH plane after constructing a 3D rendering of the data.

  14. The study on measures to improve the reliability of the hydraulic systems of shearers

    Institute of Scientific and Technical Information of China (English)

    YUAN Hui; XU Long-jiang; TIAN Da-biao; ZHAO Yan-ling

    2001-01-01

    The authors indicate that the failure of hydraulic systems of shearers can drop greatly, its' reliability and service life can be increased by the use of a field oil contamination analyser and filter device to control the oil cont amination of the hydraulic systems of shearers. Experimental provement of siltin g-theory contamination analyser are carried out.The filter effect of portable h ydraulic driving oil-filter model YLJ-21 is examinationed in laboratory and fi e ld experiment. From January to August 1992, on-site experimental research using a silting-theory contamination analyser and oil-filter model YLJ-21 to contr o l the oil contamination was carried out in the Datong Coal Mining Bureau.

  15. A study of the key problem of optimum hydraulic design for a pump system with low head%低扬程泵装置优化水力设计的关键问题

    Institute of Scientific and Technical Information of China (English)

    徐磊; 陆林广; 梁金栋; 王刚; 董雷

    2012-01-01

    An in-depth study on the problem of optimum hydraulic design for a pump system with low head has been made in this paper. The efficiency of a pump system with low head is divided into two aspects: one is pump efficiency and the other is conduit efficiency. Some problems about the definition of pump segment in the pump system, efficiency modification for the pump segment and flow pattern of inlet conduit in the pump system are discussed. The influence of conduit hydraulic loss on the conduit efficiency and pump system efficiency is analyzed and the influence of both flow velocity and flow pattern on the conduit hydraulic loss is illustrated by calculation samples, from which the conclusions are drawn as follows: under the condition of low head, the key problem of how to increase the pump system efficiency is to reduce the conduit hydraulic loss as much as possible; The essential way to reduce the conduit hydraulic loss may be to lower the flow velocity and improve the flow pattern in the conduit. The approaches to reduce the conduit hydraulic loss mainly include: to choose the type of pump system and conduit with the optimal hydraulic performance, to suitably lower pump nD value, to choose better pump model, to suitably relax the restrictions for conduit control size, and to sufficiently optimize hydraulic design for conduit shape.%对低扬程泵装置的优化水力设计问题进行了较为深入的研究.将低扬程泵装置效率分解为水泵效率和流道效率两个方面,讨论了泵装置中泵段的概念和泵段效率的修正等问题,分析了流道水力损失对流道效率及泵装置效率的影响,通过实例说明了流道内的流速和流态对流道水力损失的影响,得到以下结论:在低扬程条件下,尽可能减小流道水力损失是提高泵装置效率的关键;减小流道水力损失的关键是降低流道内的流速和改善流道内的流态,其途径主要包括选择水力性能最优的泵装置型式和流道

  16. PIV measurements of coolant flow field in a diesel engine cylinder head

    Science.gov (United States)

    Ma, Hongwei; Zhang, Zhenyang; Xue, Cheng; Huang, Yunlong

    2015-04-01

    This paper presents experimental measurements of coolant flow field in the water jacket of a diesel engine cylinder head. The test was conducted at three different flow rates using a 2-D PIV system. Appropriate tracing particles were selected and delivery device was designed and manufactured before the test. The flow parameters, such as velocity, vorticity and turbulence, were used to analyze the flow field. The effects of vortex which was located between the intake valve and the exhaust valve were discussed. The experimental results showed an asymmetric distribution of velocity in the water jacket. This led to an asymmetric thermal distribution, which would shorten the service life of the cylinder head. The structure optimization to the water jacket of cylinder head was proposed in this paper. The experimental system, especially the 2-D PIV system, is a great help to study the coolant flow structure and analyze cooling mechanism in the diesel engine cylinder head.

  17. In-situ stress measurements and stress change monitoring to monitor overburden caving behaviour and hydraulic fracture pre-conditioning

    Institute of Scientific and Technical Information of China (English)

    Puller Jesse W.; Mills Ken W.; Jeffrey Rob G.; Walker Rick J.

    2016-01-01

    A coal mine in New South Wales is longwall mining 300 m wide panels at a depth of 160–180 m directly below a 16–20 m thick conglomerate strata. As part of a strategy to use hydraulic fracturing to manage potential windblast and periodic caving hazards associated with these conglomerate strata, the in-situ stresses in the conglomerate were measured using ANZI strain cells and the overcoring method of stress relief. Changes in stress associated with abutment loading and placement of hydraulic fractures were also measured using ANZI strain cells installed from the surface and from underground. Overcore stress mea-surements have indicated that the vertical stress is the lowest principal stress so that hydraulic fractures placed ahead of mining form horizontally and so provide effective pre-conditioning to promote caving of the conglomerate strata. Monitoring of stress changes in the overburden strata during longwall retreat was undertaken at two different locations at the mine. The monitoring indicated stress changes were evi-dent 150 m ahead of the longwall face and abutment loading reached a maximum increase of about 7.5 MPa. The stresses ahead of mining change gradually with distance to the approaching longwall and in a direction consistent with the horizontal in-situ stresses. There was no evidence in the stress change monitoring results to indicate significant cyclical forward abutment loading ahead of the face. The for-ward abutment load determined from the stress change monitoring is consistent with the weight of over-burden strata overhanging the goaf indicated by subsidence monitoring.

  18. A system to measure minute hydraulic permeability of nanometer scale devices in a non-destructive manner

    Science.gov (United States)

    Smith, Ross A.; Fleischman, Aaron J.; Fissell, William H.; Zorman, Christian A.; Roy, Shuvo

    2011-04-01

    We report an automated system for measuring the hydraulic permeability of nanoporous membranes in a tangential-flow configuration. The system was designed and built specifically for micromachined silicon nanoporous membranes (SNM) with monodisperse slit-shaped pores. These novel membranes are under development for water filtration, artificial organ and drug delivery applications. The filtration cell permits non-destructive testing of the membrane over many remove-modify-replace testing cycles, allowing for direct experiments into the effects of surface modifications on such membranes. The experimental apparatus was validated using microfluidic tubing with circular cross sections that provided similar fluidic resistances to SNM. Further validation was performed with SNM chips for which the pore dimensions were known from scanning electron microscopy measurements. The system was then used to measure the hydraulic permeability of nanoporous membranes before and after surface modification. The system yields measurements with low variance and excellent agreement with predicted values, providing a platform for determining pore sizes in micro/nanofluidic systems with tight pore size distributions to a higher degree of precision than can be achieved with traditional techniques.

  19. A simple measuring technique of surface flow velocity to analyze the behavior of velocity fields in hydraulic engineering applications.

    Science.gov (United States)

    Tellez, Jackson; Gomez, Manuel; Russo, Beniamino; Redondo, Jose M.

    2015-04-01

    An important achievement in hydraulic engineering is the proposal and development of new techniques for the measurement of field velocities in hydraulic problems. The technological advances in digital cameras with high resolution and high speed found in the market, and the advances in digital image processing techniques now provides a tremendous potential to measure and study the behavior of the water surface flows. This technique was applied at the Laboratory of Hydraulics at the Technical University of Catalonia - Barcelona Tech to study the 2D velocity fields in the vicinity of a grate inlet. We used a platform to test grate inlets capacity with dimensions of 5.5 m long and 4 m wide allowing a zone of useful study of 5.5m x 3m, where the width is similar of the urban road lane. The platform allows you to modify the longitudinal slopes from 0% to 10% and transversal slope from 0% to 4%. Flow rates can arrive to 200 l/s. In addition a high resolution camera with 1280 x 1024 pixels resolution with maximum speed of 488 frames per second was used. A novel technique using particle image velocimetry to measure surface flow velocities has been developed and validated with the experimental data from the grate inlets capacity. In this case, the proposed methodology can become a useful tools to understand the velocity fields of the flow approaching the inlet where the traditional measuring equipment have serious problems and limitations. References DigiFlow User Guide. (2012), (June). Russo, B., Gómez, M., & Tellez, J. (2013). Methodology to Estimate the Hydraulic Efficiency of Nontested Continuous Transverse Grates. Journal of Irrigation and Drainage Engineering, 139(10), 864-871. doi:10.1061/(ASCE)IR.1943-4774.0000625 Teresa Vila (1), Jackson Tellez (1), Jesus Maria Sanchez (2), Laura Sotillos (1), Margarita Diez (3, 1), and J., & (1), M. R. (2014). Diffusion in fractal wakes and convective thermoelectric flows. Geophysical Research Abstracts - EGU General Assembly 2014

  20. An Experimental Study of Measuring Oscillatory and Transient Pressures in Hydraulic Systems.

    Science.gov (United States)

    1978-12-01

    dynamic conditions. One of these computer programs that was of interest in this study was the Hydraulic Systems Frequency Response (HsFR). H- SFR program...reason for that failure is that the model for the hose was not accurate enough. The predicted amplitudes were much lower than measurec’ values except...the line. 6. P(%)- in line - Pclanp on x 100 ( 6 Pin line 7. Span - The distance between two clamps. The trans- ducers were located in the center of the

  1. Comparison of laboratory, in situ, and rock mass measurements of the hydraulic conductivity of metamorphic rock at the Savannah River Plant near Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Marine, I W

    1980-01-01

    In situ testing of exploratory wells in metamorphic rock indicates that two types of fracturing occur in the rock mass. Rock containing small openings that permit only extremely slow movement of water is termed virtually impermeable rock. Rock containing openings of sufficient size to permit transmission of water at a significantly faster rate is termed hydraulically transmissive rock. Laboratory methods are unsuitable for measuring hydraulic conductivity in hydraulically transmissive rock; however, for the virtually impermeable rock, values comparable to the in situ tests are obtained. The hydraulic conductivity of the rock mass over a large region is calculated by using the hydraulic gradient, porosity, and regional velocity. This velocity is determined by dividing the inferred travel distance by the age of water which is determined by the helium content of the water. This rock mass hydraulic conductivity value is between the values measured for the two types of fractures, but is closer to the measured value for the virtually impermeable rock. This relationship is attributed to the control of the regional flow rate by the virtually impermeable rock where the discrete fractures do not form a continuous open connection through the entire rock mass. Thus, laboratory methods of measuring permeability in metamorphic rock are of value if they are properly applied.

  2. Comparison of Laboratory, in Situ, and Rock Mass Measurements of the Hydraulic Conductivity of Metamorphic Rock at the Savannah River Plant Near Aiken, South Carolina

    Science.gov (United States)

    Marine, I. Wendell

    1981-06-01

    In situ testing of exploratory wells in metamorphic rock indicates that two types of fracturing occur in the rock mass. Rock containing small openings that permit only extremely slow movement of water is termed virtually impermeable rock. Rock containing openings of sufficient size to permit transmission of water at a significantly faster rate is termed hydraulically transmissive rock. Laboratory methods are unsuitable for measuring hydraulic conductivity in hydraulically transmissive rock; however, for the virtually impermeable rock, values comparable to those of the in situ tests are obtained. The hydraulic conductivity of the rock mass over a large region is calculated by using the hydraulic gradient, porosity, and regional velocity. This velocity is determined by dividing the inferred travel distance by the age of water, which is determined by the helium content of the water. This rock mass hydraulic conductivity value is between the values measured for the two types of fractures but is closer to the measured value for the virtually impermeable rock. This relationship is attributed to the control of the regional flow rate by the virtually impermeable rock where the discrete fractures do not form a continuous open connection through the entire rock mass. Thus laboratory methods of measuring permeability in metamorphic rock are of value if they are properly applied.

  3. A device for continuous measurement of head position during PET brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.R.; Daube-Witherspoon, M.E.; Green, M.V. [National Inst. of Health, Bethesda, MD (United States)

    1994-05-01

    Head motion during PET brain imaging can seriously degrade image quality. We have shown previously (1) that the effects of such movements can be eliminated if the position of the head relative to the scanner is accurately known throughout the study. To this end, we designed, built, and tested a tracking device (TD) and head attachment fixture. The TD consists of 3 miniature lamps, attached to a rigid wire frame, that are sequentially illuminated within the field of view of two positions of the lamps are computed every 5 sec and these values are used to compute the 3 rotational and 3 translational coordinates of the frame. The accuracy of the TD was evaluated by attaching the frame to a precision mechanical rotation-translation apparatus and comparing motions in all coordinate direction. The maximum error observed in the range {plus_minus}10 mm, {plus_minus}4 deg was 0.7 mm and 0.4 deg, with largest uncertainties in the azimuthal direction. The head attachment mechanism was evaluated in 8 subjects by connecting the rigid lamp wire frame to the top of a lightweight tubular structure fitted into the ears and attached by adhesive pads to the forehead. Simultaneously, the transducer of a commercially available tracking system was attached by adhesive to the forehead. With head position being monitored by both systems, each subject was first instructed to perform a set of controlled head movements in each of the coordinate directions and then to rest normally for 5 minutes. The largest angular difference observed between the two devices in these subjects was 2 deg (azimuthal), with most differences being less than 1 deg and less than 10%. These results suggest that the TD is capable of accurately measuring small rotational and translational displacements and that the head attachment mechanism to which the lamp array is fixed follows head movement within acceptable limits.

  4. Accuracy of methods to measure femoral head penetration within metal-backed acetabular components.

    Science.gov (United States)

    Callary, Stuart A; Solomon, Lucian B; Holubowycz, Oksana T; Campbell, David G; Howie, Donald W

    2016-06-30

    A number of different software programs are used to investigate the in vivo wear of polyethylene bearings in total hip arthroplasty. With wear rates below 0.1 mm/year now commonly being reported for highly cross-linked polyethylene (XLPE) components, it is important to identify the accuracy of the methods used to measure such small movements. The aims of this study were to compare the accuracy of current software programs used to measure two-dimensional (2D) femoral head penetration (FHP) and to determine whether the accuracy is influenced by larger femoral heads or by different methods of representing the acetabular component within radiostereometric analysis (RSA). A hip phantom was used to compare known movements of the femoral head within a metal-backed acetabular component to FHP measured radiographically using RSA, Hip Analysis Suite (HAS), PolyWare, Ein Bild Roentgen Analyse (EBRA), and Roentgen Monographic Analysis Tool (ROMAN). RSA was significantly more accurate than the HAS, PolyWare, and ROMAN methods when measuring 2D FHP with a 28 mm femoral head. Femoral head size influenced the accuracy of HAS and ROMAN 2D FHP measurements, EBRA proximal measurements, and RSA measurements in the proximal and anterior direction. The use of different acetabular reference segments did not influence accuracy of RSA measurements. The superior accuracy and reduced variability of RSA wear measurements allow much smaller cohorts to be used in RSA clinical wear studies than those utilizing other software programs. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  5. Effect of head impacts on diffusivity measures in a cohort of collegiate contact sport athletes

    Science.gov (United States)

    Ford, James C.; Flashman, Laura A.; Maerlender, Arthur; Greenwald, Richard M.; Beckwith, Jonathan G.; Bolander, Richard P.; Tosteson, Tor D.; Turco, John H.; Raman, Rema; Jain, Sonia

    2014-01-01

    Objective: To determine whether exposure to repetitive head impacts over a single season affects white matter diffusion measures in collegiate contact sport athletes. Methods: A prospective cohort study at a Division I NCAA athletic program of 80 nonconcussed varsity football and ice hockey players who wore instrumented helmets that recorded the acceleration-time history of the head following impact, and 79 non–contact sport athletes. Assessment occurred preseason and shortly after the season with diffusion tensor imaging and neurocognitive measures. Results: There was a significant (p = 0.011) athlete-group difference for mean diffusivity (MD) in the corpus callosum. Postseason fractional anisotropy (FA) differed (p = 0.001) in the amygdala (0.238 vs 0.233). Measures of head impact exposure correlated with white matter diffusivity measures in several brain regions, including the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory. Conclusion: This study suggests a relationship between head impact exposure, white matter diffusion measures, and cognition over the course of a single season, even in the absence of diagnosed concussion, in a cohort of college athletes. Further work is needed to assess whether such effects are short term or persistent. PMID:24336143

  6. Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test

    Directory of Open Access Journals (Sweden)

    Leigh A. McGarvie

    2015-03-01

    Full Text Available Background/Hypothesis. With the video Head Impulse Test (vHIT, the vertical VOR gain is defined as (vertical eye velocity/vertical head velocity, but compensatory eye movements to vertical canal stimulation usually have a torsional component. To minimize the contribution of torsion to the eye movement measurement, the horizontal gaze direction should be directed 40º from straight ahead so it is in the plane of the stimulated canal plane pair. Hypothesis: as gaze is systematically moved horizontally away from canal plane alignment, the measured vertical VOR gain should decrease.Study Design. 10 healthy subjects, with vHIT measuring vertical eye movement to head impulses in the plane of the left anterior-right posterior (LARP canal plane, with gaze at one of 5 horizontal gaze positions (40º (aligned with the LARP plane, 20º, 0º, -20º, -40º.Methods. Every head impulse was in the LARP plane. The compensatory eye movement was measured by the vHIT prototype system. The one operator delivered every impulse. Results. The canal stimulus remained identical across trials, but the measured vertical VOR gain decreased as horizontal gaze angle was shifted away from alignment with the LARP canal plane.Conclusion. In measuring vertical VOR gain with vHIT the horizontal gaze angle should be aligned with the canal plane under test.

  7. Head impacts in a junior rugby league team measured with a wireless head impact sensor: an exploratory analysis.

    Science.gov (United States)

    King, Doug; Hume, Patria; Gissane, Conor; Clark, Trevor

    2017-01-01

    OBJECTIVE The aim of this study was to investigate the frequency, magnitude, and distribution of head impacts sustained by players in a junior rugby league over a season of matches. METHODS The authors performed a prospective cohort analysis of impact magnitude, frequency, and distribution on data collected with instrumented XPatches worn behind the ear of players in an "under-11" junior rugby league team (players under 11 years old). RESULTS A total of 1977 impacts were recorded. Over the course of the study, players sustained an average of 116 impacts (average of 13 impacts per player per match). The measured linear acceleration ranged from 10g to 123g (mean 22g, median 16g, and 95th percentile 57g). The rotational acceleration ranged from 89 rad/sec(2) to 22,928 rad/sec(2) (mean 4041 rad/sec(2), median 2773 rad/sec(2), and 95th percentile 11,384 rad/sec(2)). CONCLUSIONS The level of impact severity based on the magnitude of impacts for linear and rotational accelerations recorded was similar to the impacts reported in studies of American junior and high school football, collegiate football, and youth ice hockey players, but the players in the rugby league cohort were younger, had less body mass, and played at a slower speed than the American players. Junior rugby league players are required to tackle the player to the ground and use a different tackle technique than that used in American football, likely increasing the rotational accelerations recorded at the head.

  8. Xylem embolism alleviated by ion-mediated increase in hydraulic conductivity of functional xylem: insights from field measurements.

    Science.gov (United States)

    Trifilò, Patrizia; Lo Gullo, Maria A; Salleo, Sebastiano; Callea, Katia; Nardini, Andrea

    2008-10-01

    Recent studies have shown that, in some species, xylem hydraulic conductivity (K(h)) increases with increasing cation concentration of xylem sap. Evidence indicates that K(h) increases as a result of the de-swelling of pit membrane pectins caused by cation neutralization of polygalacturonanes. We tested whether this ionic effect partly compensates for the embolism-induced loss of stem hydraulic conductivity (PLC) by increasing K(h) of functioning conduits. We report changes in PLC, leaf water status and potassium concentration ([K(+)]) of xylem sap measured in April and July in two evergreens (Ceratonia siliqua L. and Phytolacca dioica L.) and one deciduous tree (Platanus orientalis L.) growing in the field in Sicily. In summer, Ceratonia siliqua and Phytolacca dioica showed similar native embolism (PLC = 30-40%) and [K(+)] of xylem sap (14 to 17 mM), and K(h) of stems perfused with 10 to 25 mM KCl increased by 15 to 18% compared with K(h) of stems perfused with a low concentration of a multi-ionic solution. In contrast, native [K(+)] of sap of Platanus orientalis was 50% of that in the two evergreens in summer, with a parallel lack of detectable changes in PLC that was below 10% in both spring and summer. The ionic effect was PLC-dependent: the enhancement of K(h) induced by 10 to 25 mM KCl changed from 15% for fully hydrated stems to 50-75% for stems with PLC = 50%. In Ceratonia siliqua, PLC was less than 10% in spring and about 40% in summer; concurrently, xylem sap [K(+)] increased from 3 to about 15 mM. This [K(+)] at the recorded PLC would cause an increase in residual K(h) of about 30%. Hence, the actual reduction in water transport capacity of Ceratonia siliqua stems in summer is about 20%. Similar calculations for Phytolacca dioica suggest that the actual loss of hydraulic conductivity in stems of this species in summer would be only about 10%, and not 30% as suggested by hydraulic measurements performed in the laboratory. We conclude that an increase in

  9. Hydraulic Hybrid and Conventional Parcel Delivery Vehicles' Measured Laboratory Fuel Economy on Targeted Drive Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lammert, M. P.; Burton, J.; Sindler, P.; Duran, A.

    2014-10-01

    This research project compares laboratory-measured fuel economy of a medium-duty diesel powered hydraulic hybrid vehicle drivetrain to both a conventional diesel drivetrain and a conventional gasoline drivetrain in a typical commercial parcel delivery application. Vehicles in this study included a model year 2012 Freightliner P100H hybrid compared to a 2012 conventional gasoline P100 and a 2012 conventional diesel parcel delivery van of similar specifications. Drive cycle analysis of 484 days of hybrid parcel delivery van commercial operation from multiple vehicles was used to select three standard laboratory drive cycles as well as to create a custom representative cycle. These four cycles encompass and bracket the range of real world in-use data observed in Baltimore United Parcel Service operations. The NY Composite cycle, the City Suburban Heavy Vehicle Cycle cycle, and the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) cycle as well as a custom Baltimore parcel delivery cycle were tested at the National Renewable Energy Laboratory's Renewable Fuels and Lubricants Laboratory. Fuel consumption was measured and analyzed for all three vehicles. Vehicle laboratory results are compared on the basis of fuel economy. The hydraulic hybrid parcel delivery van demonstrated 19%-52% better fuel economy than the conventional diesel parcel delivery van and 30%-56% better fuel economy than the conventional gasoline parcel delivery van on cycles other than the highway-oriented HHDDT cycle.

  10. Gamma ray transmission for hydraulic conductivity measurement of undisturbed soil columns

    Directory of Open Access Journals (Sweden)

    Anderson Camargo Moreira

    2007-03-01

    Full Text Available This work had the objective to determine the Hydraulic Conductivity K(theta function for different depth levels z, of columns of undisturbed soil, using the gamma ray transmission technique applied to the Sisson method. The results indicated a growing behavior for K(theta and a homogeneous soil density, both in relation to the increase of the depth. The methodology of gamma ray transmission showed satisfactory results on the determination of the hydraulic conductivity in columns of undisturbed soil, besides being very reliable and a nondestructive method.O estudo da condutividade hidráulica para solos não saturados é essencial quando aplicado às situações relacionadas à irrigação, drenagem e transporte de nutrientes no solo, é uma importante propriedade para desenvolvimentos de culturas agrícolas. Este trabalho tem o objetivo de determinar a função Condutividade Hidráulica K(teta, em diferentes níveis z de profundidade, em colunas de solo indeformado, utilizando a transmissão de raios gama aplicada ao método de Sisson. Os resultados indicam um comportamento crescente para K(teta e uma densidade de solo homogênea, ambos em relação ao aumento da profundidade. A metodologia de transmissão de raios gama mostrou resultados bastante satisfatórios na determinação da condutividade hidráulica em colunas de solo indeformado, além de ser muito confiável e não destrutivo.

  11. At what age is hydrocephalus detected, and what is the role of head circumference measurements?

    NARCIS (Netherlands)

    Breuning-Broers, J.M.; Deurloo, J.A.; Gooskens, R.H.; Verkerk, P.H.

    2014-01-01

    To investigate at what age hydrocephalus is detected and to assess the role of head circumference measurements in detecting hydrocephalus, we performed a retrospective chart review in children with hydrocephalus treated in a tertiary paediatric hospital in the Netherlands. The study group contained

  12. At what age is hydrocephalus detected, and what is the role of head circumference measurements?

    NARCIS (Netherlands)

    Breuning-Broers, J.M.; Deurloo, J.A.; Gooskens, R.H.; Verkerk, P.H.

    2014-01-01

    To investigate at what age hydrocephalus is detected and to assess the role of head circumference measurements in detecting hydrocephalus, we performed a retrospective chart review in children with hydrocephalus treated in a tertiary paediatric hospital in the Netherlands. The study group contained

  13. Some comparisons of binaural measurements made with different dummy heads and stereo microphone techniques

    Science.gov (United States)

    Mapp, Peter A.

    2004-10-01

    Binaural measurements have been made in a number of acoustic environments, and the results from different binaural heads and stereo microphones are compared. The object of the study was not only to establish what practical differences occurred between the various head formats, but also to see if a stereo microphone or pseudohead could be used for making auditorium binaural measurements. Five measurement platforms were employed. These included two binaural dummy heads, binaural in-ear probe microphones, an SAAS pseudohead stereo microphone and a M-S (midside) stereo microphone. In the latter case, three different midside ratios were employed and compared. The measurements were made in a reverberant recital hall (2.5-s RT) and small acoustically treated listening room (RT 0.2 s). Whereas relatively minor differences were found to occur between the heads, significant differences were found to occur with the stereo microphones. It is concluded that while useful information can be obtained from a stereo microphone, it is far from being the same as binaural.

  14. HYDRAULIC SERVO

    Science.gov (United States)

    Wiegand, D.E.

    1962-05-01

    A hydraulic servo is designed in which a small pressure difference produced at two orifices by an electrically operated flapper arm in a constantly flowing hydraulic loop is hydraulically amplified by two constant flow pumps, two additional orifices, and three unconnected ball pistons. Two of the pistons are of one size and operate against the additional orifices, and the third piston is of a different size and operates between and against the first two pistons. (AEC)

  15. Validation of a noninvasive system for measuring head acceleration for use during boxing competition.

    Science.gov (United States)

    Beckwith, Jonathan G; Chu, Jeffrey J; Greenwald, Richard M

    2007-08-01

    Although the epidemiology and mechanics of concussion in sports have been investigated for many years, the biomechanical factors that contribute to mild traumatic brain injury remain unclear because of the difficulties in measuring impact events in the field. The purpose of this study was to validate an instrumented boxing headgear (IBH) that can be used to measure impact severity and location during play. The instrumented boxing headgear data were processed to determine linear and rotational acceleration at the head center of gravity, impact location, and impact severity metrics, such as the Head Injury Criterion (HIC) and Gadd Severity Index (GSI). The instrumented boxing headgear was fitted to a Hybrid III (HIII) head form and impacted with a weighted pendulum to characterize accuracy and repeatability. Fifty-six impacts over 3 speeds and 5 locations were used to simulate blows most commonly observed in boxing. A high correlation between the HIII and instrumented boxing headgear was established for peak linear and rotational acceleration (r2= 0.91), HIC (r2 = 0.88), and GSI (r2 = 0.89). Mean location error was 9.7 +/- 5.2 masculine. Based on this study, the IBH is a valid system for measuring head acceleration and impact location that can be integrated into training and competition.

  16. Accuracy of a Wearable Sensor for Measures of Head Kinematics and Calculation of Brain Tissue Strain.

    Science.gov (United States)

    Knowles, Brooklynn M; Yu, Henry; Dennison, Christopher R

    2017-02-01

    Wearable kinematic sensors can be used to study head injury biomechanics based on kinematics and, more recently, based on tissue strain metrics using kinematics-driven brain models. These sensors require in-situ calibration and there is currently no data conveying wearable ability to estimate tissue strain. We simulated head impact (n = 871) to a 50th percentile Hybrid III (H-III) head wearing a hockey helmet instrumented with wearable GForceTracker (GFT) sensors measuring linear acceleration and angular velocity. A GFT was also fixed within the H-III head to establish a lower boundary on systematic errors. We quantified GFT errors relative to H-III measures based on peak kinematics and cumulative strain damage measure (CSDM). The smallest mean errors were 12% (peak resultant linear acceleration) and 15% (peak resultant angular velocity) for the GFT within the H-III. Errors for GFTs on the helmet were on average 54% (peak resultant linear acceleration) and 21% (peak resultant angular velocity). On average, the GFT inside the helmet overestimated CSDM by 0.15.

  17. Photosensor-Based Latency Measurement System for Head-Mounted Displays

    Directory of Open Access Journals (Sweden)

    Min-Woo Seo

    2017-05-01

    Full Text Available In this paper, a photosensor-based latency measurement system for head-mounted displays (HMDs is proposed. The motion-to-photon latency is the greatest reason for motion sickness and dizziness felt by users when wearing an HMD system. Therefore, a measurement system is required to accurately measure and analyze the latency to reduce these problems. The existing measurement system does not consider the actual physical movement in humans, and its accuracy is also very low. However, the proposed system considers the physical head movement and is highly accurate. Specifically, it consists of a head position model-based rotary platform, pixel luminance change detector, and signal analysis and calculation modules. Using these modules, the proposed system can exactly measure the latency, which is the time difference between the physical movement for a user and the luminance change of an output image. In the experiment using a commercial HMD, the latency was measured to be up to 47.05 ms. In addition, the measured latency increased up to 381.17 ms when increasing the rendering workload in the HMD.

  18. A Novel Three-Head Ultrasonic System for Distance Measurements Based on the Correlation Method

    Directory of Open Access Journals (Sweden)

    Gądek Krzysztof

    2014-12-01

    Full Text Available A novel double-emitter ultrasonic system for distance measurements based on the correlation method is presented. The proposed distance measurement method may be particularly useful in difficult conditions, e.g. for media parameters undergoing fast changes or in cases when obstacles and mechanical interference produce false reflections. The system is a development of a previously studied single-head idea. The present article covers a comparison of the two systems in terms of efficiency and precision. Experimental research described in this paper indicated that adding the second head improved the measurement exactness – standard deviation decreased by 40%. The correlation method is also described in detail, also giving the criterion for the quality of the measurement signal.

  19. Evaluation of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. Part 2. Two-stage regulated pump/turbines for operating heads of 1000 to 1500 m

    Energy Technology Data Exchange (ETDEWEB)

    Blomquist, C.A.; Frigo, A.A.; Degnan, J.R.

    1979-10-01

    This UPHS report applies to Francis-type, reversible pump/turbines regulated with gating systems. The first report, however, covered single-stage regulations; this report covers two-stage regulations. Development of a two-stage regulated pump/turbine appears to be attractive because the proposed single-drop UPHS concept requires turbomachinery with a head range of 1000 to 2000 m. With turbomachinery of this range available, the single-drop scheme offers a simple and economic UPHS option. Six different two-stage, top-gated pump/turbines have been analyzed: three that generate 500 MW and three that generate 350 MW. In each capacity, one machine has an operating head of 1000 m, another has a head of 1250 m, and the third has a head of 1500 m. The rated efficiencies of the machines vary from about 90% (1000-m head) to about 88% (1500-m head). Costs in 1978 $/kW for the three 500-MW units are: 20.5 (1000 m), 16.5 (1250 m), and 13.5 (1500 m). Corresponding costs for the three 350-MW units are 23, 18, and 14 $/kW. No major turbomachinery obstacles are foreseen that could hamper development of these pump/turbines. Further model testing and development are needed before building them.

  20. International benchmark study of advanced thermal hydraulic safety analysis codes against measurements on IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hainoun, A., E-mail: pscientific2@aec.org.sy [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Doval, A. [Nuclear Engineering Department, Av. Cmdt. Luis Piedrabuena 4950, C.P. 8400 S.C de Bariloche, Rio Negro (Argentina); Umbehaun, P. [Centro de Engenharia Nuclear – CEN, IPEN-CNEN/SP, Av. Lineu Prestes 2242-Cidade Universitaria, CEP-05508-000 São Paulo, SP (Brazil); Chatzidakis, S. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States); Ghazi, N. [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Park, S. [Research Reactor Design and Engineering Division, Basic Science Project Operation Dept., Korea Atomic Energy Research Institute (Korea, Republic of); Mladin, M. [Institute for Nuclear Research, Campului Street No. 1, P.O. Box 78, 115400 Mioveni, Arges (Romania); Shokr, A. [Division of Nuclear Installation Safety, Research Reactor Safety Section, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2014-12-15

    Highlights: • A set of advanced system thermal hydraulic codes are benchmarked against IFA of IEA-R1. • Comparative safety analysis of IEA-R1 reactor during LOFA by 7 working teams. • This work covers both experimental and calculation effort and presents new out findings on TH of RR that have not been reported before. • LOFA results discrepancies from 7% to 20% for coolant and peak clad temperatures are predicted conservatively. - Abstract: In the framework of the IAEA Coordination Research Project on “Innovative methods in research reactor analysis: Benchmark against experimental data on neutronics and thermal hydraulic computational methods and tools for operation and safety analysis of research reactors” the Brazilian research reactor IEA-R1 has been selected as reference facility to perform benchmark calculations for a set of thermal hydraulic codes being widely used by international teams in the field of research reactor (RR) deterministic safety analysis. The goal of the conducted benchmark is to demonstrate the application of innovative reactor analysis tools in the research reactor community, validation of the applied codes and application of the validated codes to perform comprehensive safety analysis of RR. The IEA-R1 is equipped with an Instrumented Fuel Assembly (IFA) which provided measurements for normal operation and loss of flow transient. The measurements comprised coolant and cladding temperatures, reactor power and flow rate. Temperatures are measured at three different radial and axial positions of IFA summing up to 12 measuring points in addition to the coolant inlet and outlet temperatures. The considered benchmark deals with the loss of reactor flow and the subsequent flow reversal from downward forced to upward natural circulation and presents therefore relevant phenomena for the RR safety analysis. The benchmark calculations were performed independently by the participating teams using different thermal hydraulic and safety

  1. Evaluating lysimeter drainage against soil deep percolation modeled with profile soil moisture, field tracer propagation, and lab measured soil hydraulic properties

    DEFF Research Database (Denmark)

    Vasquez, Vicente; Thomsen, Anton Gårde; Iversen, Bo Vangsø;

    them have been reported. To compare among methods, one year of four large-scale lysimeters drainage (D) was evaluated against modeled soil deep percolation using either profile soil moisture, bromide breakthrough curves from suction cups, or measured soil hydraulic properties in the laboratory...... model using field q, and 572 mm with the laboratory measured soil hydraulic properties. In conclusion, lysimeters presented the lowest D and can be considered as a lower bound for D; whereas either laboratory measured soil hydraulic properties or models calibrated with profile soil moisture yielded......Quantifying recharge to shallow aquifers via soil deep percolation is needed for sustainable management of water resources. This includes modeled predictions to address the effects of climate change on recharge. Different methods to estimate soil deep percolation exist but few comparisons among...

  2. Permeâmetro de carga decrescente associado a programa computacional para a determinação da condutividade hidráulica do solo saturado Falling head permeameter and software to determine the hydraulic conductivity of saturated soil

    Directory of Open Access Journals (Sweden)

    Paulo Ivonir Gubiani

    2010-06-01

    Full Text Available A condutividade hidráulica do solo saturado (Kθs é uma propriedade com grande variabilidade, o que exige a utilização de um número maior de determinações para que sua descrição possa ser feita adequadamente pela função densidade de probabilidade normal. Consequentemente, há aumento de trabalho e de tempo para a obtenção dos resultados, principalmente se as determinações forem feitas com equipamentos de pouca praticidade. A construção de equipamentos de maior praticidade e o desenvolvimento de ferramentas computacionais podem tornar o processo de análise mais rápido e preciso. Com esse objetivo, foi construído um permeâmetro de carga decrescente e desenvolvido um software para a aquisição de dados. As medidas de Kθs obtidas com esses equipamentos, em amostras de um Argissolo, mostraram menor variabilidade, avaliada pelo coeficiente de variação, o que resultou em maior precisão das determinações. Além disso, o tempo de análise foi reduzido em 30 %.The soil saturated hydraulic conductivity (Kθs is a property with great variability, which requires the use of a greater number of determinations so that they can be described by the normal probability density function. Consequently, there is an increase in time and labor to obtain Kθs results if determined by conventional equipment. The use of more practical equipment and computational tools allows a faster and more accurate analysis. With this aim a falling head permeameter was built and a software for data acquisition was developed. Values of Kθs obtained with this equipment in Hapludalf samples showed less variability, as assessed by the coefficient of variation, resulting in more precise measurements. Moreover, the time of analysis was reduced by 30 %.

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

    Directory of Open Access Journals (Sweden)

    PURECE C.

    2016-12-01

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

  4. Self-aligned cantilever positioning for on-substrate measurements using DVD pickup head

    DEFF Research Database (Denmark)

    Bosco, Filippo; Hwu, E. T.; Keller, Stephan Urs

    2010-01-01

    In this paper, we present a novel approach for measuring the resonant frequency of cantilevers fabricated in polymeric materials. We re-designed the use of a commercial DVD-ROM pickup head and combine it with a glass-polymer substrate in order to obtain a light and portable device to measure...... the resonant frequency of polymer cantilevers. The use of the Pyrex-SU-8 clamping substrate allows an easy replacement of the cantilever chips and a fast alignment process to the DVD-ROM laser beam. We show measurements of thermal noise for SU-8 and TOPAS cantilevers in air and liquid environment....

  5. Basic hydraulics

    CERN Document Server

    Smith, P D

    1982-01-01

    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  6. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  7. Maneuvering impact boring head

    Science.gov (United States)

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  8. A novel device for head gesture measurement system in combination with eye-controlled human machine interface

    Science.gov (United States)

    Lin, Chern-Sheng; Ho, Chien-Wa; Chang, Kai-Chieh; Hung, San-Shan; Shei, Hung-Jung; Yeh, Mau-Shiun

    2006-06-01

    This study describes the design and combination of an eye-controlled and a head-controlled human-machine interface system. This system is a highly effective human-machine interface, detecting head movement by changing positions and numbers of light sources on the head. When the users utilize the head-mounted display to browse a computer screen, the system will catch the images of the user's eyes with CCD cameras, which can also measure the angle and position of the light sources. In the eye-tracking system, the program in the computer will locate each center point of the pupils in the images, and record the information on moving traces and pupil diameters. In the head gesture measurement system, the user wears a double-source eyeglass frame, so the system catches images of the user's head by using a CCD camera in front of the user. The computer program will locate the center point of the head, transferring it to the screen coordinates, and then the user can control the cursor by head motions. We combine the eye-controlled and head-controlled human-machine interface system for the virtual reality applications.

  9. Measurement of radiation dose to ovaries from CT of the head and trunk

    Energy Technology Data Exchange (ETDEWEB)

    Al-Habdhan, M.A.M.; Kinsara, A.R. [King Abdul Aziz Univ., Nuclear Engineering Dept., Jeddah (Saudi Arabia)

    2001-07-01

    With the rise in concern about doses received by patients over recent years, there has been a growing requirement for information on typical doses and the range of dose received during Computerized Tomography (CT). This study was performed for the assessment of radiation dose to the ovaries from various CT protocols for head and trunk imaging. Thermo luminescent dosimeters (TLD) were used for the dosimetry measurement in an anthropomorphic Rando Alderson phantom. The wanted (obligatory) and unwanted (non-useful) radiation doses delivered to the ovaries during CT examinations of head, facial bone, orbits, abdomen, chest, pelvis, neck, nasopharynx, cervical spine, lumber spine and sacroiliac joint were assessed. The results are compared with the corresponding values published in the literature. A comparison of the received dose from CT examinations and general radiography examinations by the ovaries was made. It is found that relatively high doses of unwanted radiation are delivered with computerized tomography. (author)

  10. Minimal-Drift Heading Measurement using a MEMS Gyro for Indoor Mobile Robots

    Science.gov (United States)

    Hong, Sung Kyung; Park, Sungsu

    2008-01-01

    To meet the challenges of making low-cost MEMS yaw rate gyros for the precise self-localization of indoor mobile robots, this paper examines a practical and effective method of minimizing drift on the heading angle that relies solely on integration of rate signals from a gyro. The main idea of the proposed approach is consists of two parts; 1) self-identification of calibration coefficients that affects long-term performance, and 2) threshold filter to reject the broadband noise component that affects short-term performance. Experimental results with the proposed phased method applied to Epson XV3500 gyro demonstrate that it effectively yields minimal drift heading angle measurements getting over major error sources in the MEMS gyro output.

  11. Development of a Three-Dimensional Measuring System for Neonates' Head and Facial Morphology

    Institute of Scientific and Technical Information of China (English)

    DENG Yong-mei; YICK Kit-lun; KWOK Yi-lin; WONG Siu-chun; Ng Sun-pui

    2007-01-01

    A web camera based multi-camera convergent close-range photogrammetric system is developed to obtain the neonates' head and facial morphology. The data will then be used to develop a secure and good-fitting eye-patch protector for neonates, particularly when they are exposed to bright lights such as phototherapy light. Measurements obtained by the system are evaluated and validated against data obtained from optical scanning. Results show that the photogrammetric system meets the requirements of measuring accuracy and safety for neonate in the neonatal units.

  12. Dyke leakage localization and hydraulic permeability estimation through self-potential and hydro-acoustic measurements: Self-potential 'abacus' diagram for hydraulic permeability estimation and uncertainty computation

    Science.gov (United States)

    Bolève, A.; Vandemeulebrouck, J.; Grangeon, J.

    2012-11-01

    In the present study, we propose the combination of two geophysical techniques, which we have applied to a dyke located in southeastern France that has a visible downstream flood area: the self-potential (SP) and hydro-acoustic methods. These methods are sensitive to two different types of signals: electric signals and water-soil pressure disturbances, respectively. The advantages of the SP technique lie in the high rate of data acquisition, which allows assessment of long dykes, and direct diagnosis in terms of leakage area delimitation and quantification. Coupled with punctual hydro-acoustic cartography, a leakage position can be precisely located, therefore allowing specific remediation decisions with regard to the results of the geophysical investigation. Here, the precise localization of leakage from an earth dyke has been identified using SP and hydro-acoustic signals, with the permeability of the preferential fluid flow area estimated by forward SP modeling. Moreover, we propose a general 'abacus' diagram for the estimation of hydraulic permeability of dyke leakage according to the magnitude of over water SP anomalies and the associated uncertainty.

  13. Recovery of individual head-related transfer functions from a small set of measurements.

    Science.gov (United States)

    Xie, Bo-Sun

    2012-07-01

    Head-related transfer functions (HRTFs) vary with individuals, and in practice, measuring HRTFs with high directional resolution for each individual is tiresome. Based on a basis functions representation of HRTFs, the present work proposes a method for recovering individual HRTFs from a small set of measurements. The HRTFs are represented by a combination of a small set of spatial basis functions (SBFs) with frequency- and individual-dependent weights. The SBFs are derived by applying spatial principal component analysis to a baseline HRTF dataset with high directional resolution. The individual weights for any subject outside the dataset are estimated from measurements at a few source directions, and then the HRTFs with high directional resolution are recovered by combining the SBFs and the individual weights. In an illustrative case, the SBFs derived from a baseline dataset that includes 20 subjects are used to recover the HRTF magnitudes for six subjects outside the baseline dataset. Results show that individual HRTF magnitudes can be recovered from measurements at 73 directions with a mean signal-to-distortion ratio of 19 dB. The proposed method is also applicable to recovering head-related impulse responses. The results of psychoacoustic experiments indicate that in most cases the recovered and measured HRTFs are indistinguishable.

  14. Wireless inertial measurement of head kinematics in freely-moving rats

    Science.gov (United States)

    Pasquet, Matthieu O.; Tihy, Matthieu; Gourgeon, Aurélie; Pompili, Marco N.; Godsil, Bill P.; Léna, Clément; Dugué, Guillaume P.

    2016-01-01

    While miniature inertial sensors offer a promising means for precisely detecting, quantifying and classifying animal behaviors, versatile inertial sensing devices adapted for small, freely-moving laboratory animals are still lacking. We developed a standalone and cost-effective platform for performing high-rate wireless inertial measurements of head movements in rats. Our system is designed to enable real-time bidirectional communication between the headborne inertial sensing device and third party systems, which can be used for precise data timestamping and low-latency motion-triggered applications. We illustrate the usefulness of our system in diverse experimental situations. We show that our system can be used for precisely quantifying motor responses evoked by external stimuli, for characterizing head kinematics during normal behavior and for monitoring head posture under normal and pathological conditions obtained using unilateral vestibular lesions. We also introduce and validate a novel method for automatically quantifying behavioral freezing during Pavlovian fear conditioning experiments, which offers superior performance in terms of precision, temporal resolution and efficiency. Thus, this system precisely acquires movement information in freely-moving animals, and can enable objective and quantitative behavioral scoring methods in a wide variety of experimental situations. PMID:27767085

  15. Scale dependence of the hydraulic properties of a fractured aquifer estimated using transfer functions

    Science.gov (United States)

    Pedretti, D.; Russian, A.; Sanchez-Vila, X.; Dentz, M.

    2016-07-01

    We present an investigation of the scale dependence of hydraulic parameters in fractured media based on the concept of transfer functions (TF). TF methods provide an inexpensive way to perform aquifer parameter estimation, as they relate the fluctuations of an observation time series (hydraulic head fluctuations) to an input function (aquifer recharge) in frequency domain. Fractured media are specially sensitive to this approach as hydraulic parameters are strongly scale-dependent, involving nonstationary statistical distributions. Our study is based on an extensive data set, involving up to 130 measurement points with periodic head measurements that in some cases extend for more than 30 years. For each point, we use a single-porosity and dual-continuum TF formulation to obtain a distribution of transmissivities and storativities in both mobile and immobile domains. Single-porosity TF estimates are compared with data obtained from the interpretation of over 60 hydraulic tests (slug and pumping tests). Results show that the TF is able to estimate the scale dependence of the hydraulic parameters, and it is consistent with the behavior of estimates from traditional hydraulic tests. In addition, the TF approach seems to provide an estimation of the system variance and the extension of the ergodic behavior of the aquifer (estimated in approximately 500 m in the analyzed aquifer). The scale dependence of transmissivity seems to be independent from the adopted formulation (single or dual-continuum), while storativity is more sensitive to the presence of multiple continua.

  16. Evaluation of linear measurements of implant sites based o head orientation during acquisition: An ex vivo study using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sabban, Hanadi; Mahdian, Mina; Dhingra, Ajay; Lurie, Alan G.; Tadinada, Aditya [University of Connecticut School of Dental Medicine, Farmington (United States)

    2015-06-15

    This study evaluated the effect of various head orientations during cone-beam computed tomography (CBCT) image acquisition on linear measurements of potential implant sites. Six dry human skulls with a total of 28 implant sites were evaluated for seven different head orientations. The scans were acquired using a Hitachi CB-MercuRay CBCT machine. The scanned volumes were reconstructed. Horizontal and vertical measurements were made and were compared to measurements made after simulating the head position to corrected head angulations. Data was analyzed using a two-way ANOVA test. Statistical analysis revealed a significant interaction between the mean errors in vertical measurements with a marked difference observed at the extension head position (P<0.05). Statistical analysis failed to yield any significant interaction between the mean errors in horizontal measurements at various head positions. Head orientation could significantly affect the vertical measurements in CBCT scans. The main head position influencing the measurements is extension.

  17. Estimating river discharge from earth observation measurement of river surface hydraulic variables

    Directory of Open Access Journals (Sweden)

    J. Negrel

    2010-10-01

    Full Text Available River discharge is a key variable to quantify the water cycle, its fluxes and stocks at different scales, from local scale for the efficient management of water resource to global scale for the monitoring of climate change. Therefore, developing Earth observation (EO techniques for the measurement or estimation of river discharge is a major challenge. A key question deals with the possibility of deriving river discharge values from EO surface variables (width, level, slope, velocity the only one accessible through EO without any in situ measurement. Based on a literature study and original developments, the possibilities of estimating water surface variables using remote-sensing techniques have been explored, mainly RADAR altimetry as well as across-track and along-track interferometry.

  18. Hydraulic Tomography at North Campus Research Site: Let Data Tell the Story

    Science.gov (United States)

    Tso, C. H. M.; Yeh, T. C. J.

    2014-12-01

    Hydraulic tomography (HT) is a sequential cross-hole hydraulic test followed by inversion of the data to map the spatial distribution of aquifer hydraulic properties (Yeh and Liu, 2000). We provide a focused, qualitative discussion on the hydraulic tomography data reported in Berg and Illman (2011). At the North Campus Research Site (NCRS) of the University of Waterloo, 8 pumping tests are conducted sequentially at different locations of the well field while drawdown is monitored at 44 ports distributed at 8 other wells. Without conducting inverse modeling, we discuss the behavior of the drawdown curves and the temporal evolution head field in response to pumping location, heterogeneity in aquifer parameters (i.e. hydraulic conductivity (K) and specific storage (Ss)), flow regimes, and boundary conditions. We emphasize the importance and direct benefits for conducting hydraulic tomography surveys relies primarily on the collection of non-redundant data, not on the inverse models. This paper attempts to use an intuitive/logical approach to qualitative hydraulic tomography analysis. Our interpretation on the aquifer heterogeneity largely agrees with the intensive core sampling (i.e. local K measurements) and inverse modeling results. We conclude some of the inspection procedures can be beneficial before the inversion of data, while the quantitative and unifying estimation of hydraulic parameter fields can only be done using an inverse model.

  19. Experimental Development and Demonstration of Ultrasonic Measurement Diagnostics for Sodium Fast Reactor Thermal-hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Tokuhiro, Akira; Jones, Byron

    2013-09-13

    This research project will address some of the principal technology issues related to sodium-cooled fast reactors (SFR), primarily the development and demonstration of ultrasonic measurement diagnostics linked to effective thermal convective sensing under normatl and off-normal conditions. Sodium is well-suited as a heat transfer medium for the SFR. However, because it is chemically reactive and optically opaque, it presents engineering accessibility constraints relative to operations and maintenance (O&M) and in-service inspection (ISI) technologies that are currently used for light water reactors. Thus, there are limited sensing options for conducting thermohydraulic measurements under normal conditions and off-normal events (maintenance, unanticipated events). Acoustic methods, primarily ultrasonics, are a key measurement technology with applications in non-destructive testing, component imaging, thermometry, and velocimetry. THis project would have yielded a better quantitative and qualitative understanding of the thermohydraulic condition of solium under varied flow conditions. THe scope of work will evaluate and demonstrate ultrasonic technologies and define instrumentation options for the SFR.

  20. Estimation of electrical conductivity distribution within the human head from magnetic flux density measurement.

    Science.gov (United States)

    Gao, Nuo; Zhu, S A; He, Bin

    2005-06-01

    We have developed a new algorithm for magnetic resonance electrical impedance tomography (MREIT), which uses only one component of the magnetic flux density to reconstruct the electrical conductivity distribution within the body. The radial basis function (RBF) network and simplex method are used in the present approach to estimate the conductivity distribution by minimizing the errors between the 'measured' and model-predicted magnetic flux densities. Computer simulations were conducted in a realistic-geometry head model to test the feasibility of the proposed approach. Single-variable and three-variable simulations were performed to estimate the brain-skull conductivity ratio and the conductivity values of the brain, skull and scalp layers. When SNR = 15 for magnetic flux density measurements with the target skull-to-brain conductivity ratio being 1/15, the relative error (RE) between the target and estimated conductivity was 0.0737 +/- 0.0746 in the single-variable simulations. In the three-variable simulations, the RE was 0.1676 +/- 0.0317. Effects of electrode position uncertainty were also assessed by computer simulations. The present promising results suggest the feasibility of estimating important conductivity values within the head from noninvasive magnetic flux density measurements.

  1. Measurement of hard tissue density of head phantom based on the HU by using CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Sun; Kang, Dong Wan; Kim, Jae Duk [School of Dentistry, Chosun University, Gwangju (Korea, Republic of)

    2009-09-15

    The purpose of this study was to determine a conversion coefficient for Hounsfield Units(HU) to material density (g cm{sup -3}) obtained from cone-beam computed tomography (CBMercuRay{sup TM}) data and to measure the hard tissue density based on the Hounsfield scale on dental head phantom. CT Scanner Phantom (AAPM) equipped with CT Number Insert consists of five cylindrical pins of materials with different densities and teflon ring was scanned by using the CBMercuRay{sup TM} (Hitachi, Tokyo, Japan) volume scanner. The raw data were converted into DICOM format and the HU of different areas of CT number insert measured by using CBWorks{sup TM}. Linear regression analysis and Student t-test were performed statistically. There was no significant difference (P>0.54) between real densities and measured densities. A linear regression was performed using the density, {rho} (g cm{sup -3}), as the dependent variable in terms of the HU (H). The regression equation obtained was {rho}=0.00072 H-0.01588 with an R2 value of 0.9968. Density values based on the Hounsfield scale was 1697.1 {+-} 24.9 HU in cortical bone, 526.5 {+-} 44.4 HU in trabecular bone, 2639.1 {+-} 48.7 HU in enamel, 1246.1 {+-} 39.4 HU in dentin of dental head phantom. CBCT provides an effective option for determination of material density expressed as Hounsfield Units.

  2. The Cambridge Face Tracker: Accurate, Low Cost Measurement of Head Posture Using Computer Vision and Face Recognition Software

    Science.gov (United States)

    Thomas, Peter B. M.; Baltrušaitis, Tadas; Robinson, Peter; Vivian, Anthony J.

    2016-01-01

    Purpose We validate a video-based method of head posture measurement. Methods The Cambridge Face Tracker uses neural networks (constrained local neural fields) to recognize facial features in video. The relative position of these facial features is used to calculate head posture. First, we assess the accuracy of this approach against videos in three research databases where each frame is tagged with a precisely measured head posture. Second, we compare our method to a commercially available mechanical device, the Cervical Range of Motion device: four subjects each adopted 43 distinct head postures that were measured using both methods. Results The Cambridge Face Tracker achieved confident facial recognition in 92% of the approximately 38,000 frames of video from the three databases. The respective mean error in absolute head posture was 3.34°, 3.86°, and 2.81°, with a median error of 1.97°, 2.16°, and 1.96°. The accuracy decreased with more extreme head posture. Comparing The Cambridge Face Tracker to the Cervical Range of Motion Device gave correlation coefficients of 0.99 (P < 0.0001), 0.96 (P < 0.0001), and 0.99 (P < 0.0001) for yaw, pitch, and roll, respectively. Conclusions The Cambridge Face Tracker performs well under real-world conditions and within the range of normally-encountered head posture. It allows useful quantification of head posture in real time or from precaptured video. Its performance is similar to that of a clinically validated mechanical device. It has significant advantages over other approaches in that subjects do not need to wear any apparatus, and it requires only low cost, easy-to-setup consumer electronics. Translational Relevance Noncontact assessment of head posture allows more complete clinical assessment of patients, and could benefit surgical planning in future. PMID:27730008

  3. The Cambridge Face Tracker: Accurate, Low Cost Measurement of Head Posture Using Computer Vision and Face Recognition Software.

    Science.gov (United States)

    Thomas, Peter B M; Baltrušaitis, Tadas; Robinson, Peter; Vivian, Anthony J

    2016-09-01

    We validate a video-based method of head posture measurement. The Cambridge Face Tracker uses neural networks (constrained local neural fields) to recognize facial features in video. The relative position of these facial features is used to calculate head posture. First, we assess the accuracy of this approach against videos in three research databases where each frame is tagged with a precisely measured head posture. Second, we compare our method to a commercially available mechanical device, the Cervical Range of Motion device: four subjects each adopted 43 distinct head postures that were measured using both methods. The Cambridge Face Tracker achieved confident facial recognition in 92% of the approximately 38,000 frames of video from the three databases. The respective mean error in absolute head posture was 3.34°, 3.86°, and 2.81°, with a median error of 1.97°, 2.16°, and 1.96°. The accuracy decreased with more extreme head posture. Comparing The Cambridge Face Tracker to the Cervical Range of Motion Device gave correlation coefficients of 0.99 (P Cambridge Face Tracker performs well under real-world conditions and within the range of normally-encountered head posture. It allows useful quantification of head posture in real time or from precaptured video. Its performance is similar to that of a clinically validated mechanical device. It has significant advantages over other approaches in that subjects do not need to wear any apparatus, and it requires only low cost, easy-to-setup consumer electronics. Noncontact assessment of head posture allows more complete clinical assessment of patients, and could benefit surgical planning in future.

  4. Near-saturated hydraulic conductivity: database development, meta-analysis and pedotransfer functions

    Science.gov (United States)

    Jarvis, Nicholas; Koestel, John; Messing, Ingmar; Lindahl, Anna

    2013-04-01

    Near-saturated hydraulic conductivity exerts a critical control on water flow and solute transport through the vadose zone, yet very little is known concerning how it is influenced by various soil properties and site factors and attributes. Starting from the 1980's, tension infiltrometers or disc permeameters have become an increasingly popular method to measure near-saturated hydraulic conductivity in undisturbed soil. In this presentation, we describe the development and organization of a large database of tension infiltrometer measurements (n>700) collated from the published literature. The raw datasets were standardized and summarized using a modified Kozeny-Carman model of near-saturated hydraulic conductivity (Jarvis, N.J. 2008. Near-saturated hydraulic properties of macroporous soils. Vadose Zone Journal, 7, 1302-1310). This model was found to accurately describe near-saturated conductivity for this large dataset (92% of cases had R2 values larger than 0.9). We will show the results of some initial analyses of the dataset, which show how hydraulic conductivity at pressure heads of -1 and -10 cm, as well as the slope of the near-saturated conductivity function, are affected by: i.) the choice of method to convert unconfined 3D infiltration to hydraulic conductivity, and ii.) interactions between soil properties such as texture and bulk density and site attributes such as land use and climate. We will also present some initial attempts to develop pedotransfer functions for parameters describing near-saturated hydraulic conductivity using the technique of random forests.

  5. Assessing the likely value of gravity and drawdown measurements to constrain estimates of hydraulic conductivity and specific yield during unconfined aquifer testing

    Science.gov (United States)

    Blainey, J.B.; Ferre, T. P. A.; Cordova, J.T.

    2007-01-01

    Pumping of an unconfined aquifer can cause local desaturation detectable with high-resolution gravimetry. A previous study showed that signal-to-noise ratios could be predicted for gravity measurements based on a hydrologic model. We show that although changes should be detectable with gravimeters, estimations of hydraulic conductivity and specific yield based on gravity data alone are likely to be unacceptably inaccurate and imprecise. In contrast, a transect of low-quality drawdown data alone resulted in accurate estimates of hydraulic conductivity and inaccurate and imprecise estimates of specific yield. Combined use of drawdown and gravity data, or use of high-quality drawdown data alone, resulted in unbiased and precise estimates of both parameters. This study is an example of the value of a staged assessment regarding the likely significance of a new measurement method or monitoring scenario before collecting field data. Copyright 2007 by the American Geophysical Union.

  6. 高水头条件下氯离子击穿高岭土衬垫的离心模型试验研究%Centrifuge Modeling for Chloridion Breaking Through Kaolin Clay Liner with High Hydraulic Head

    Institute of Scientific and Technical Information of China (English)

    詹良通; 曾兴; 李育超; 钟孝乐; 陈云敏

    2012-01-01

    One-dimensional chloridion movement in a Kaolin clay liner is modeled by using 400 g-t. Centrifuge machine, liner model is prepared by consolidating a high water content Kaolin slurry in 1 g condition. The breakthrough of chloridion in the Kaolin clay liner under high hydraulic head is successfully simulated at SO g centrifugal acceleration for 3 hours and 52 minutes. The results indicate the liner model experienced further consolidation in the centrifuge due to the induced seepage force, and the consolidation-induced seepage resulted in a transient flow in the early stage. The transient flow influenced the chloridion movement process, which is inconsistent with the condition of Ogata's analytical solution (1961) for one-dimensional advection-dispersion problem. An equivalent time method is proposed in this paper to analyze the test results. The prototype breakthrough time was predicted by the fitted parameters. The experimental results demonstrated that under a hydraulic head of 10 m, the breakthrough time for 2 m-thick Kaolin clay liner with a hydraulic conductivity of 3.2 x 10-9 m/s was 1.97 year, and the stable leakage rate was 0.604 m/yr.%利用400 g-t土工离心机模拟了高水头条件下氯离子在高岭土衬垫中的一维运移及击穿过程.在1g条件下采用高含水率的高岭土泥浆加压固结制备形成衬垫模型,离心模型试验离心加速度50 g,历时3 h 52 min,成功模拟了高水头条件下氯离子击穿黏土衬垫的过程.试验结果表明:离心状态下模型在高渗透压力作用发生再固结,在约30 min固结过程中模型发生了非稳定渗流,对早期污染物运移过程具有一定的影响,导致该运移过程与Ogata (1961)提出的污染物一维对流-扩散解析解的求解条件有所差异.采用等效时间的方法对试验结果进行拟合,根据拟合的参数预测原型的击穿时间,发现渗透系数为3.2×10-9 m/s的2 m厚黏土衬垫在上覆10 m水头作用下的击穿时间仅为1

  7. Measurement of head impacts in collegiate football players: clinical measures of concussion after high- and low-magnitude impacts.

    Science.gov (United States)

    McCaffrey, Meghan A; Mihalik, Jason P; Crowell, Dean H; Shields, Edgar W; Guskiewicz, Kevin M

    2007-12-01

    It has been speculated that a theoretical injury threshold of 70 to 75 g may exist for concussions in football players. We aimed to investigate acute balance and neurocognitive performance after head impacts exceeding a theoretical injury threshold in the absence of both self-reported symptoms and a concussion diagnosis 24 hours before testing. Forty-three Division I collegiate football players participated in this double-blind, repeated-measures study. Subjects participated in three test sessions (baseline, low impact, and high impact) separated by at least 2 weeks. The Head Impact Telemetry System (Simbex, Lebanon, NH) recorded real-time head impacts sustained during practices and games. The Automated Neuropsychological Assessment Metrics assessed neurocognitive performance. The NeuroCom Sensory Organization Test (NeuroCom International Inc., Clackamas, OR) assessed postural stability. The Graded Symptom Checklist evaluated symptom presence and severity in our participants. After the low-impact test session (90 g) with improvements in Math Processing (F(1, 22) = 16.629; P < 0.001), Procedural Reaction Time (F(1, 22) = 14.668; P < 0.001), and the total number of symptoms reported (F(1, 22) = 10.267; P = 0.004). Neurocognitive improvements were likely attributed to a learning effect. Our findings suggest that sustaining an impact greater than 90 g does not result in acute observable balance and neurocognitive deficits within 24 hours of sustaining the impact. Although previous studies have suggested a theoretical injury threshold, none have been founded on empirical data collected on the playing field in real-time. Future studies should consider the cumulative effects of impacts of varying magnitudes.

  8. A Comparison between Deep and Shallow Stress Fields in Korea Using Earthquake Focal Mechanism Inversions and Hydraulic Fracturing Stress Measurements

    Science.gov (United States)

    Lee, Rayeon; Chang, Chandong; Hong, Tae-kyung; Lee, Junhyung; Bae, Seong-Ho; Park, Eui-Seob; Park, Chan

    2016-04-01

    We are characterizing stress fields in Korea using two types of stress data: earthquake focal mechanism inversions (FMF) and hydraulic fracturing stress measurements (HF). The earthquake focal mechanism inversion data represent stress conditions at 2-20 km depths, whereas the hydraulic fracturing stress measurements, mostly conducted for geotechnical purposes, have been carried out at depths shallower than 1 km. We classified individual stress data based on the World Stress Map quality ranking scheme. A total of 20 FMF data were classified into A-B quality, possibly representing tectonic stress fields. A total of 83 HF data out of compiled 226 data were classified into B-C quality, which we use for shallow stress field characterization. The tectonic stress, revealed from the FMF data, is characterized by a remarkable consistency in its maximum stress (σ1) directions in and around Korea (N79±2° E), indicating a quite uniform deep stress field throughout. On the other hand, the shallow stress field, represented by HF data, exhibits local variations in σ1 directions, possibly due to effects of topography and geologic structures such as faults. Nonetheless, there is a general similarity in σ1 directions between deep and shallow stress fields. To investigate the shallow stress field statistically, we follow 'the mean orientation and wavelength analysis' suggested by Reiter et al. (2014). After the stress pattern analysis, the resulting stress points distribute sporadically over the country, not covering the entire region evenly. In the western part of Korea, the shallow σ1directions are generally uniform with their search radius reaching 100 km, where the average stress direction agrees well with those of the deep tectonic stress. We note two noticeable differences between shallow and deep stresses in the eastern part of Korea. First, the shallow σ1 orientations are markedly non-uniform in the southeastern part of Korea with their search radius less than 25 km

  9. Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

    OpenAIRE

    2016-01-01

    Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site comparisons for contrasting climate regimes and multiple vegetation types via the integration of measurement and mod...

  10. Head-related transfer functions of the barn owl: measurement and neural responses.

    Science.gov (United States)

    Keller, C H; Hartung, K; Takahashi, T T

    1998-04-01

    Sounds arriving at the eardrum are filtered by the external ear and associated structures in a frequency and direction specific manner. When convolved with the appropriate filters and presented to human listeners through headphones, broadband noises can be precisely localized to the corresponding position outside of the head (reviewed in Blauert, 1997). Such a 'virtual auditory space' can be a potentially powerful tool for neurophysiological and behavioral work in other species as well. We are developing a virtual auditory space for the barn owl, Tyto alba, a highly successful auditory predator that has become a well-established model for hearing research. We recorded catalogues of head-related transfer functions (HRTFs) from the frontal hemisphere of 12 barn owls and compared virtual and free sound fields acoustically and by their evoked neuronal responses. The inner ca. 1 cm of the ear canal was found to contribute little to the directionality of the HRTFs. HRTFs were recorded by inserting probetube microphones to within about 1 or 2 mm of the eardrum. We recorded HRTFs at frequencies between 2 and 11 kHz, which includes the frequencies most useful to the owl for sound localization (3-9 kHz; Konishi, 1973). Spectra of virtual sounds were within +/- 1 dB of amplitude and +/- 10 degrees of phase of the spectra of free field sounds measured near to the eardrum. The spatial pattern of responses obtained from neurons in the inferior colliculus were almost indistinguishable in response to virtual and to free field stimulation.

  11. Laboratory Validation of Two Wearable Sensor Systems for Measuring Head Impact Severity in Football Players.

    Science.gov (United States)

    Siegmund, Gunter P; Guskiewicz, Kevin M; Marshall, Stephen W; DeMarco, Alyssa L; Bonin, Stephanie J

    2016-04-01

    Wearable sensors can measure head impact frequency and magnitude in football players. Our goal was to quantify the impact detection rate and validity of the direction and peak kinematics of two wearable sensors: a helmet system (HITS) and a mouthguard system (X2). Using a linear impactor, modified Hybrid-III headform and one helmet model, we conducted 16 impacts for each system at 12 helmet sites and 5 speeds (3.6-11.2 m/s) (N = 896 tests). Peak linear and angular accelerations (PLA, PAA), head injury criteria (HIC) and impact directions from each device were compared to reference sensors in the headform. Both sensors detected ~96% of impacts. Median angular errors for impact directions were 34° for HITS and 16° for X2. PLA, PAA and HIC were simultaneously valid at 2 sites for HITS (side, oblique) and one site for X2 (side). At least one kinematic parameter was valid at 2 and 7 other sites for HITS and X2 respectively. Median relative errors for PLA were 7% for HITS and -7% for X2. Although sensor validity may differ for other helmets and headforms, our analyses show that data generated by these two sensors need careful interpretation.

  12. Feasibility of measuring dissolved carbon dioxide based on head space partial pressures

    Science.gov (United States)

    Watten, B.J.; Boyd, C.E.; Schwartz, M.F.; Summerfelt, S.T.; Brazil, B.L.

    2004-01-01

    We describe an instrument prototype that measures dissolved carbon dioxide (DC) without need for standard wetted probe membranes or titration. DC is calculated using Henry's Law, water temperature, and the steady-state partial pressure of carbon dioxide that develops within the instrument's vertical gas-liquid contacting chamber. Gas-phase partial pressures were determined with either an infrared detector (ID) or by measuring voltage developed by a pH electrode immersed in an isolated sodium carbonate solution (SC) sparged with recirculated head space gas. Calculated DC concentrations were compared with those obtained by titration over a range of DC (2, 4, 8, 12, 16, 20, 24, and 28mg/l), total alkalinity (35, 120, and 250mg/l as CaCO3), total dissolved gas pressure (-178 to 120 mmHg), and dissolved oxygen concentrations (7, 14, and 18 mg/l). Statistically significant (P method was 1.3%. In a third test series, a single ID was coupled with four replicate head space units so as to permit sequential monitoring (15 min intervals) of a common water source. Here, appropriate gas samples were secured using a series of solenoid valves (1.6 mm bore) activated by a time-based controller. This system configuration reduced the capital cost per sample site from US$ 2695 to 876. Absolute error averaged 2.9, 3.1, 3.7, and 2.7 mg/ l for replicates 1-4 (N = 36) during a 21-day test period (DC range, 36-40 mg/l). The ID meter was then modified so as to provide for DO as well as DC measurements across components of an intensive fish production system. ?? 2003 Elsevier B.V. All rights reserved.

  13. Trismus in head and neck cancer patients treated by telecobalt and effect of early rehabilitation measures.

    Science.gov (United States)

    Nagaraja, Sindhu; Kadam, S Amrut; Selvaraj, Karthikeyan; Ahmed, Iqbal; Javarappa, Rajesh

    2016-01-01

    Trismus is one of the common late side effects of radiotherapy (RT) of head and neck cancers. It occurs in about 30% of patients treated by telecobalt. It, in turn, leads to significant morbidity, including malnutrition, difficulty in speaking, and compromised oral hygiene with severe psychosocial, and economic impacts. To determine the prevalence of trismus and its progression in patients who have received radical concurrent chemoradiation for head and neck cancer by telecobalt at our institution. To note the effect of early rehabilitative measures on the severity of trismus and to assess its impact on the quality of life (QOL). A total of 47 evaluable patients of head and neck cancer patients treated by telecobalt with radical intent between January 2012 and December 2013 were analyzed and baseline maximal inter-incisal opening (MIO) and MIO at the completion of RT, after 3 months, 6 months, and 1 year, after completion of RT were noted. Grading of trismus was done using Modified Common Toxicity Criteria (CTCAE Version 3.0). QOL assessment was done using European Organization for Research and Treatment of Cancer QLQ-HN35. The time when the rehabilitative measures were started were also noted. Chi-square test with Fisher exact probability test and Students t-test. Radiation-induced trismus (RIT) was seen in 31.9%, 34.04%, and 38.39% of cases at 3, 6, and 12 months after completion of RT. Grade II and III trismus accounted for 17.02% and 6.38% at the end of 1 year. Patients who started regular rehabilitative exercises soon, after completion of RT had a better mean MIO as compared to those who were not compliant (32 mm vs. 24 mm at 1 year), and there was a trend toward delayed progression in them. Trismus was also seen to adversely affect QOL of the patients. RIT is a major cause for late morbidity in patients treated with conventional RT leading to poor QOL. Early rehabilitative measures are useful in preventing progression of trismus.

  14. The Safety Measure Improvement of the Hydraulic Experiment Station%液压教学实验台安全措施的改进

    Institute of Scientific and Technical Information of China (English)

    刘体龙; 赵保平; 刘志民; 苏茹茹

    2011-01-01

    液压实验教学,经常需要操作者对系统回路的工作压力进行过程控制,而对缺乏实践经验的大学生来说,很容易出现压力超调(过载).针对这一特点,分析QCS008液压综合教学实验台的安全问题,并提出具体的改进措施.%In hydraulic experimental teaching, the operators are required to have the knowledge to control the working pressure of the system loop. However, because of the lack of practical experience, undergraduates usually make the station overload. Aiming at this issue, the security measures of QCS008 hydraulic experiment station were analyzed and the concrete improvement method was pro posed.

  15. 液压冲击的分析计算及减小措施%Analysis and Calculation of Hydraulic Impact and its Reduction Measures

    Institute of Scientific and Technical Information of China (English)

    徐成东

    2016-01-01

    从液压冲击发生的机理出发,提出造成液压冲击的两大因素是管道阀门突然关闭和运动部件迅速制动或换向,并对其分别进行了详细的分析和计算,提出了具体的减小措施。%Based on the occurrence mechanism of hydraulic impact , it is put forward that two causes of hydraulic impact are sudden closing of the pipeline valve and quick braking or reversing of the moving part .Detailed analysis and calculation have been performed respectively and specific reduction measures have been proposed .

  16. Hamiltonian Monte Carlo algorithm for the characterization of hydraulic conductivity from the heat tracing data

    Science.gov (United States)

    Djibrilla Saley, A.; Jardani, A.; Soueid Ahmed, A.; Raphael, A.; Dupont, J. P.

    2016-11-01

    Estimating spatial distributions of the hydraulic conductivity in heterogeneous aquifers has always been an important and challenging task in hydrology. Generally, the hydraulic conductivity field is determined from hydraulic head or pressure measurements. In the present study, we propose to use temperature data as source of information for characterizing the spatial distributions of the hydraulic conductivity field. In this way, we performed a laboratory sandbox experiment with the aim of imaging the heterogeneities of the hydraulic conductivity field from thermal monitoring. During the laboratory experiment, we injected a hot water pulse, which induces a heat plume motion into the sandbox. The induced plume was followed by a set of thermocouples placed in the sandbox. After the temperature data acquisition, we performed a hydraulic tomography using the stochastic Hybrid Monte Carlo approach, also called the Hamiltonian Monte Carlo (HMC) algorithm to invert the temperature data. This algorithm is based on a combination of the Metropolis Monte Carlo method and the Hamiltonian dynamics approach. The parameterization of the inverse problem was done with the Karhunen-Loève (KL) expansion to reduce the dimensionality of the unknown parameters. Our approach has provided successful reconstruction of the hydraulic conductivity field with low computational effort.

  17. Combining 3D Hydraulic Tomography with Tracer Tests for Improved Transport Characterization.

    Science.gov (United States)

    Sanchez-León, E; Leven, C; Haslauer, C P; Cirpka, O A

    2016-07-01

    Hydraulic tomography (HT) is a method for resolving the spatial distribution of hydraulic parameters to some extent, but many details important for solute transport usually remain unresolved. We present a methodology to improve solute transport predictions by combining data from HT with the breakthrough curve (BTC) of a single forced-gradient tracer test. We estimated the three dimensional (3D) hydraulic-conductivity field in an alluvial aquifer by inverting tomographic pumping tests performed at the Hydrogeological Research Site Lauswiesen close to Tübingen, Germany, using a regularized pilot-point method. We compared the estimated parameter field to available profiles of hydraulic-conductivity variations from direct-push injection logging (DPIL), and validated the hydraulic-conductivity field with hydraulic-head measurements of tests not used in the inversion. After validation, spatially uniform parameters for dual-domain transport were estimated by fitting tracer data collected during a forced-gradient tracer test. The dual-domain assumption was used to parameterize effects of the unresolved heterogeneity of the aquifer and deemed necessary to fit the shape of the BTC using reasonable parameter values. The estimated hydraulic-conductivity field and transport parameters were subsequently used to successfully predict a second independent tracer test. Our work provides an efficient and practical approach to predict solute transport in heterogeneous aquifers without performing elaborate field tracer tests with a tomographic layout.

  18. Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2011-13

    Science.gov (United States)

    Twining, Brian V.; Fisher, Jason C.

    2015-01-01

    From 2011 to 2013, the U.S. Geological Survey’s Idaho National Laboratory (INL) Project Office, in cooperation with the U.S. Department of Energy, collected depth-discrete measurements of fluid pressure and temperature in 11 boreholes located in the eastern Snake River Plain aquifer. Each borehole was instrumented with a multilevel monitoring system (MLMS) consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers.

  19. The measurement of the velocity of abrasive particles at the suction part of the cutting head

    OpenAIRE

    Foldyna, J. (Josef); M. Zeleňák; Klich, J. (Jiří); Hlaváček, P.; Sitek, L. (Libor)

    2013-01-01

    To be able to optimize the design of the abrasive cutting head using numerical simulation, it is necessary to gather as much information about processes occurring in the cutting head as possible. The development of the numerical model of processes occurring in the abrasive water jet cutting head during the process of creation and forming of abrasive water jet is currently in progress at the Institute of Geonics in Ostrava. The verification of the model requires, among others, to determine the...

  20. The measurement of the velocity of abrasive particlesat the suction part of the cutting head

    OpenAIRE

    Foldyna, J. (Josef); M. Zeleňák; Klich, J. (Jiří); Hlaváček, P.; Sitek, L. (Libor); Z. Říha

    2015-01-01

    To be able to optimize the design of the abrasive cutting head using numerical simulation, it is necessary to gather as much information about processes occurring in the cutting head as possible. The development of the numerical model of processes occurring in the abrasive water jet cutting head during the process of creation and forming of abrasive water jet is currently in progress at the Institute of Geonics in Ostrava. The verification of the model requires, among others, to determine the...

  1. Stomatal dynamics are limited by leaf hydraulics in ferns and conifers: results from simultaneous measurements of liquid and vapour fluxes in leaves.

    Science.gov (United States)

    Martins, Samuel C V; McAdam, Scott A M; Deans, Ross M; DaMatta, Fábio M; Brodribb, Tim J

    2016-03-01

    Stomatal responsiveness to vapour pressure deficit (VPD) results in continuous regulation of daytime gas-exchange directly influencing leaf water status and carbon gain. Current models can reasonably predict steady-state stomatal conductance (gs ) to changes in VPD but the gs dynamics between steady-states are poorly known. Here, we used a diverse sample of conifers and ferns to show that leaf hydraulic architecture, in particular leaf capacitance, has a major role in determining the gs response time to perturbations in VPD. By using simultaneous measurements of liquid and vapour fluxes into and out of leaves, the in situ fluctuations in leaf water balance were calculated and appeared to be closely tracked by changes in gs thus supporting a passive model of stomatal control. Indeed, good agreement was found between observed and predicted gs when using a hydropassive model based on hydraulic traits. We contend that a simple passive hydraulic control of stomata in response to changes in leaf water status provides for efficient stomatal responses to VPD in ferns and conifers, leading to closure rates as fast or faster than those seen in most angiosperms.

  2. Hydraulic Actuators with Autonomous Hydraulic Supply for the Mainline Aircrafts

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2014-01-01

    Full Text Available Applied in the aircraft control systems, hydraulic servo actuators with autonomous hydraulic supply, so-called, hydraulic actuators of integrated configuration, i.e. combination of a source of hydraulic power and its load in the single unit, are aimed at increasing control system reliability both owing to elimination of the pipelines connecting the actuator to the hydraulic supply source, and owing to avoidance of influence of other loads failure on the actuator operability. Their purpose is also to raise control system survivability by eliminating the long pipeline communications and their replacing for the electro-conductive power supply system, thus reducing the vulnerability of systems. The main reason for a delayed application of the hydraulic actuators in the cutting-edge aircrafts was that such aircrafts require hydraulic actuators of considerably higher power with considerable heat releases, which caused an unacceptable overheat of the hydraulic actuators. Positive and negative sides of the hydraulic actuators, their alternative options of increased reliability and survivability, local hydraulic systems as an advanced alternative to independent hydraulic actuators are considered.Now to use hydraulic actuators in mainline aircrafts is inexpedient since there are the unfairly large number of the problems reducing, first and last, safety of flights, with no essential weight and operational advantages. Still works to create competitive hydraulic actuators ought to be continued.Application of local hydraulic systems (LHS will allow us to reduce length of pressure head and drain pipelines and mass of pipelines, as well as to raise their general fail-safety and survivability. Application of the LHS principle will allow us to use a majority of steering drive advantages. It is necessary to allocate especially the following:- ease of meeting requirements for the non-local spread of the engine weight;- essentially reducing length and weight of

  3. WATER ENERGY IN HYDROAMELIORATIVE SYSTEMS USING THE HYDRAULIC TRANSFORMER TYPE A. BARGLAZAN AND THE HYDRAULIC HAMMER (HYDRAULIC PUMP

    Directory of Open Access Journals (Sweden)

    Teodor Eugen Man

    2010-01-01

    Full Text Available This paper presents two examples of exploitation of water energy that can be used in the irrigation field. First of theseexamples is the hydraulic transformer type A. Barglazan used for irrigation, pumped water is taken directly from theriver’s well, using a hydraulic pump which simultaneously carried out a double transformation in this way: hydraulicenergy into mechanic energy and mechanical energy into hydraulic energy. Technology preparation and devices designwas done in record time, seeing that this constructive solution is more robust, reliable and with improved energyperformance versus the laboratory prototype. The experimental research which was made at 1:1 scale proved theirgood function over time. Another example is the hydraulic hammer (hydraulic pump that uses low-head energy topump water, with a global efficiency of about 10 - 50%. Currently, the new situation of private ownership of landprovides conditions for new pumping microstations to be made where irrigation is necessary and optimal hydrauliclocations exist.

  4. Diamond-coated probe head for measurements in the deep SOL and beyond

    DEFF Research Database (Denmark)

    Schrittwieser, R.; Xu, G. S.; Yan, Ning;

    We have tested two cylindrical graphite probe heads coated by a layer of electrically isolating UNCD (Ultra Nano-Crystalline Diamond) using a CVD (Chemical Vapour Deposition) method. The probe heads were mounted on the reciprocating probe manipulator of the Experimental Advanced Superconducting T...

  5. Repeatability and reproducibility of optic nerve head perfusion measurements using optical coherence tomography angiography

    Science.gov (United States)

    Chen, Chieh-Li; Bojikian, Karine D.; Xin, Chen; Wen, Joanne C.; Gupta, Divakar; Zhang, Qinqin; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) has increasingly become a clinically useful technique in ophthalmic imaging. We evaluate the repeatability and reproducibility of blood perfusion in the optic nerve head (ONH) measured using optical microangiography (OMAG)-based OCTA. Ten eyes from 10 healthy volunteers are recruited and scanned three times with a 68-kHz Cirrus HD-OCT 5000-based OMAG prototype system (Carl Zeiss Meditec Inc., Dublin, California) centered at the ONH involving two separate visits within six weeks. Vascular images are generated with OMAG processing by detecting the differences in OCT signals between consecutive B-scans acquired at the same retina location. ONH perfusion is quantified as flux, vessel area density, and normalized flux within the ONH for the prelaminar, lamina cribrosa, and the full ONH. Coefficient of variation (CV) and intraclass correlation coefficient (ICC) are used to evaluate intravisit and intervisit repeatability, and interobserver reproducibility. ONH perfusion measurements show high repeatability [CV≤3.7% (intravisit) and ≤5.2% (intervisit)] and interobserver reproducibility (ICC≤0.966) in all three layers by three metrics. OCTA provides a noninvasive method to visualize and quantify ONH perfusion in human eyes with excellent repeatability and reproducibility, which may add additional insight into ONH perfusion in clinical practice.

  6. Measurement of field-saturated hydraulic conductivity on fractured rock outcrops near Altamura (Southern Italy) with an adjustable large ring infiltrometer

    Science.gov (United States)

    Caputo, M.C.; de Carlo, L.; Masciopinto, C.; Nimmo, J.R.

    2010-01-01

    Up to now, field studies set up to measure field-saturated hydraulic conductivity to evaluate contamination risks, have employed small cylinders that may not be representative of the scale of measurements in heterogeneous media. In this study, a large adjustable ring infiltrometer was designed to be installed on-site directly on rock to measure its field-saturated hydraulic conductivity. The proposed device is inexpensive and simple to implement, yet also very versatile, due to its large adjustable diameter that can be fixed on-site. It thus allows an improved representation of the natural system's heterogeneity, while also taking into consideration irregularities in the soil/rock surface. The new apparatus was tested on an outcrop of karstic fractured limestone overlying the deep Murge aquifer in the South of Italy, which has recently been affected by untreated sludge disposal, derived from municipal and industrial wastewater treatment plants. The quasi-steady vertical flow into the unsaturated fractures was investigated by measuring water levels during infiltrometer tests. Simultaneously, subsurface electrical resistivity measurements were used to visualize the infiltration of water in the subsoil, due to unsaturated water flow in the fractures. The proposed experimental apparatus works well on rock outcrops, and allows the repetition of infiltration tests at many locations in order to reduce model uncertainties in heterogeneous media. ?? 2009 Springer-Verlag.

  7. Integration of Tracer Test Data to Refine Geostatistical Hydraulic Conductivity Fields Using Sequential Self-Calibration Method

    Institute of Scientific and Technical Information of China (English)

    Bill X Hu; Jiang Xiaowei; Wan Li

    2007-01-01

    On the basis of local measurements of hydraulic conductivity, geostatistical methods have been found to be useful in heterogeneity characterization of a hydraulic conductivity field on a regional scale. However, the methods are not suited to directly integrate dynamic production data, such as,hydraulic head and solute concentration, into the study of conductivity distribution. These data, which record the flow and transport processes in the medium, are closely related to the spatial distribution of hydraulic conductivity. In this study, a three-dimensional gradient-based inverse method-the sequential self-calibration (SSC) method-is developed to calibrate a hydraulic conductivity field,initially generated by a geostatistical simulation method, conditioned on tracer test results. The SSC method can honor both local hydraulic conductivity measurements and tracer test data. The mismatch between the simulated hydraulic conductivity field and the reference true one, measured by its mean square error (MSE), is reduced through the SSC conditional study. In comparison with the unconditional results, the SSC conditional study creates the mean breakthrough curve much closer to the reference true curve, and significantly reduces the prediction uncertainty of the solute transport in the observed locations. Further, the reduction of uncertainty is spatially dependent, which indicates that good locations, geological structure, and boundary conditions will affect the efficiency of the SSC study results.

  8. Influence of automated disc margin determination on Stratus OCT optic nerve head measurements

    Directory of Open Access Journals (Sweden)

    Soares de Camargo A

    2014-03-01

    Full Text Available André Soares de Camargo, Luiz Alberto Soares Melo Jr, Flavio Eduardo Hirai, Ivan Maynart Tavares Glaucoma Service, Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Paulista Medical School, São Paulo, Brazil Purpose: To analyze the influence of manual correction of the automatically determined edge of the optic nerve head (ONH in optic disc measurements in cases in which the optical coherence tomography did not identify the disc limits correctly. Methods: The study included 127 eyes from 127 consecutive patients with glaucoma, suspects, and healthy individuals. In a retrospective analysis, eyes that underwent testing with the Stratus OCT (software version 4.0, Carl Zeiss Meditec, Dublin, CA, USA Fast Optic Disc protocol were evaluated. Forty-seven eyes in which either the manual assignment was not necessary or the signal strength was below six were excluded. After image acquisition and processing, one expert examiner manually corrected the determination of the edge of the ONH, identified as the end of the retinal pigment epithelium/choriocapillaris complex. Disc area, cup area, rim area, and cup/disc area ratio results were compared before and after the optic disc margin manually corrected determination. Paired t-test was performed to evaluate the differences, and Bland–Altman plots were used to display the relationships between measurements. Results: Eighty eyes from 80 individuals were included in the analyses. No statistically significant difference (P=0.538 was found when analyzing results obtained with automated and manual determination of rim area (mean ± standard deviation; 1.30±0.45 mm2 and 1.29±0.39 mm2, respectively. Cup area (1.39±0.58 mm2 and 1.31±0.55 mm2, respectively, cup/disc area ratio (0.50±0.16 mm2 and 0.49±0.15 mm2, respectively, and disc area results (2.69±0.55 mm2 and 2.60±0.51 mm2, respectively were significantly different. Conclusion: The Stratus OCT ONH Report results were

  9. Thermal Hydraulic Performance of Tight Lattice Bundle

    Science.gov (United States)

    Yamamoto, Yasushi; Akiba, Miyuki; Morooka, Shinichi; Shirakawa, Kenetsu; Abe, Nobuaki

    Recently, the reduced moderation spectrum BWR has been studied. The fast neutron spectrum is obtained through triangular tight lattice fuel. However, there are few thermal hydraulic test data and thermal hydraulic correlation applicable to critical power prediction in such a tight lattice bundle. This study aims to enhance the database of the thermal hydraulic performance of the tight lattice bundle whose rod gap is about 1mm. Therefore, thermal hydraulic performance measurement tests of tight lattice bundles for the critical power, the pressure drop and the counter current flow limiting were performed. Moreover, the correlations to evaluate the thermal-hydraulic performance of the tight lattice bundle were developed.

  10. Hydraulic conductivity of organomodified soil

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, R.B.; Grant, J.M.; Voice, T.C.; Rakhshandehroo, G.; Xu, S.; Boyd, S.A. [Michigan State Univ., East Lansing, MI (United States)

    1995-11-01

    The effects of organomodification on soil hydraulic conductivity were investigated. Hydraulic conductivity and porosity of treated and untreated samples of a sandy loam were measured as a function of effective stress. Batch treatment with hexadecyltrimethyl ammonium (HDTMA) and dry packing produced organomodified samples that were 79% less conducive than untreated samples prior to loading. Treated samples lost less hydraulic conductivity as a result of loading than untreated samples so that treated samples had higher conductivity at high loads. Observed differences in conductivity are explained in terms of the role of the treated and untreated clay in controlling initial effective pore size and its change during consolidation.

  11. 21 CFR 870.2780 - Hydraulic, pneumatic, or photoelectric plethysmographs.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydraulic, pneumatic, or photoelectric... § 870.2780 Hydraulic, pneumatic, or photoelectric plethysmographs. (a) Identification. A hydraulic... using hydraulic, pneumatic, or photoelectric measurement techniques. (b) Classification. Class...

  12. A mini slug test method for determination of a local hydraulic conductivity of an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Hinsby, Klaus; Bjerg, Poul Løgstrup; Andersen, Lars J.;

    1992-01-01

    from level to level and thereby establish vertical profiles of the hydraulic conductivity. The head data from the test well are recorded with a 10 mm pressure transducer, and the initial head difference required is established by a small vacuum pump. The method described has provided 274 spatially......A new and efficient mini slug test method for the determination of local hydraulic conductivities in unconfined sandy aquifers is developed. The slug test is performed in a small-diameter (1 inch) driven well with a 0.25 m screen just above the drive point. The screened drive point can be driven...... distributed measurements of a local hydraulic conductivity at a tracer test site at Vejen, Denmark. The mini slug test results calculated by a modified Dax slug test analysing method, applying the elastic storativity in the Dax equations instead of the specific yield, are in good accordance with the results...

  13. Flow-Log Analysis for Hydraulic Characterization of Selected Test Wells at the Indian Point Energy Center, Buchanan, New York

    Science.gov (United States)

    Williams, John H.

    2008-01-01

    Flow logs from 24 test wells were analyzed as part of the hydraulic characterization of the metamorphosed and fractured carbonate bedrock at the Indian Point Energy Center in Buchanan, New York. The flow logs were analyzed along with caliper, optical- and acoustic-televiewer, and fluid-resistivity and temperature logs to determine the character and distribution of fracture-flow zones and estimate their transmissivities and hydraulic heads. Many flow zones were associated with subhorizontal to shallow-dipping fractured zones, southeast-dipping bedding fractures, northwest-dipping conjugate fractures, or combinations of bedding and conjugate fractures. Flow-log analysis generally provided reasonable first-order estimates of flow-zone transmissivity and head differences compared with the results of conventional hydraulic-test analysis and measurements. Selected results of an aquifer test and a tracer test provided corroborating information in support of the flow-log analysis.

  14. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

    NARCIS (Netherlands)

    Jager-Wittenaar, H.; Dijkstra, P. U.; Vissink, A.; van Oort, R. P.; Roodenburg, J. L. N.

    2009-01-01

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this Study was to analyse the variation in mouth-opening measurem

  15. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

    NARCIS (Netherlands)

    Jager-Wittenaar, H.; Dijkstra, P. U.; Vissink, A.; van Oort, R. P.; Roodenburg, J. L. N.

    2009-01-01

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this Study was to analyse the variation in mouth-opening measurem

  16. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus

    NARCIS (Netherlands)

    Jager-Wittenaar, H.; Dijkstra, P. U.; Vissink, A.; van Oort, R. P.; Roodenburg, J. L. N.

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this Study was to analyse the variation in mouth-opening

  17. The usefulness of 3D quantitative analysis with using MRI for measuring osteonecrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Young; Lee, Sun Wha [Ewha Womans University College of Medicine, Seoul (Korea, Republic of); Park, Youn Soo [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2006-11-15

    We wanted to evaluate the usefulness of MRI 3D quantitative analysis for measuring osteonecrosis of the femoral head in comparison with MRI 2D quantitative analysis and quantitative analysis of the specimen. For 3 months at our hospital, 14 femoral head specimens with osteonecrosis were obtained after total hip arthroplasty. The patients preoperative MRIs were retrospectively reviewed for quantitative analysis of the size of the necrosis. Each necrotic fraction of the femoral head was measured by 2D quantitative analysis with using mid-coronal and mid-sagittal MRIs, and by 3D quantitative analysis with using serial continuous coronal MRIs and 3D reconstruction software. The necrotic fraction of the specimen was physically measured by the fluid displacement method. The necrotic fraction according to MRI 2D or 3D quantitative analysis was compared with that of the specimen by using Spearman's correlation test. On the correlative analysis, the necrotic fraction by MRI 2D quantitative analysis and quantitative analysis of the specimen showed moderate correlation (r = 0.657); on the other hand, the necrotic fraction by MRI 3D quantitative analysis and quantitative analysis of the specimen demonstrated a strong correlation (r = 0.952) ({rho} < 0.05). MRI 3D quantitative analysis was more accurate than 2D quantitative analysis using MRI for measuring osteonecrosis of the femoral head. Therefore, it may be useful for predicting the clinical outcome and deciding the proper treatment option.

  18. Measuring Deformation in the Mouse Optic Nerve Head and Peripapillary Sclera

    Science.gov (United States)

    Nguyen, Cathy; Midgett, Dan; Kimball, Elizabeth C.; Steinhart, Matthew R.; Nguyen, Thao D.; Pease, Mary E.; Oglesby, Ericka N.; Jefferys, Joan L.; Quigley, Harry A.

    2017-01-01

    Purpose To develop an ex vivo explant system using multiphoton microscopy and digital volume correlation to measure the full-field deformation response to intraocular pressure (IOP) change in the peripapillary sclera (PPS) and in the optic nerve head (ONH) astrocytic structure. Methods Green fluorescent protein (GFP)-glutamate transporter-GLT1 (GLT1/GFP) mouse eyes were explanted and imaged with a laser-scanning microscope under controlled inflation. Images were analyzed for regional strains and changes in astrocytic lamina and PPS shape. Astrocyte volume fraction in seven control GLT1/GFP mice was measured. The level of fluorescence of GFP fluorescent astrocytes was compared with glial fibrillary acidic protein (GFAP) labeled astrocytes using immunohistochemistry. Results The ONH astrocytic structure remained stable during 3 hours in explants. Control strain—globally, in the central one-half or two-thirds of the astrocytic lamina—was significantly greater in the nasal-temporal direction than in the inferior-superior or anterior-posterior directions (each P ≤ 0.03, mixed models). The PPS opening (perimeter) in normal eye explants also became wider nasal-temporally than superior-inferiorly during inflation from 10 to 30 mm Hg (P = 0.0005). After 1 to 3 days of chronic IOP elevation, PPS area was larger than in control eyes (P = 0.035), perimeter elongation was 37% less than controls, and global nasal-temporal strain was significantly less than controls (P = 0.007). Astrocyte orientation was altered by chronic IOP elevation, with processes redirected toward the longitudinal axis of the optic nerve. Conclusions The explant inflation test measures the strain response of the mouse ONH to applied IOP. Initial studies indicate regional differences in response to both acute and chronic IOP elevation within the ONH region. PMID:28146237

  19. Research on hydraulic slotting technology controlling coal-gas outbursts

    Institute of Scientific and Technical Information of China (English)

    WEI Guo-ying; SHAN Zhi-yong; ZHANG Zi-min

    2008-01-01

    Measured to control serious coal-gas outburst in coal seam were analyzed by theory and experimented in test site. A new technique to distress the coal-bed and drain methane, called hydraulic slotting, was described in detail, and the mechanism of hydrau-lic slotting was put forward and analyzed. The characteristic parameter of hydraulic slotting was given in Jiaozuo mining area and the characteristic of validity, adaptability and secu-rity was evaluated. The results show that the stress surrounding the strata and the gas in coal seam is released efficiently and thoroughly while new techniques are taken, as slot-ting at heading face by high pressure large diameter jet. The resistance to coal and gas outbursts is increased dramatically once the area of slotting is increased to a certain size.In the process of driving 2 000 m tunnel by hydraulic slotting excavation, coal and gas outburst never occurre. The technique could be used to prevent and control potential coal-gas outburst in the proceeding of tunnel driving, and the speed tunneling could be as high as more than 2 times.

  20. Improved measurement of brain deformation during mild head acceleration using a novel tagged MRI sequence.

    Science.gov (United States)

    Knutsen, Andrew K; Magrath, Elizabeth; McEntee, Julie E; Xing, Fangxu; Prince, Jerry L; Bayly, Philip V; Butman, John A; Pham, Dzung L

    2014-11-07

    In vivo measurements of human brain deformation during mild acceleration are needed to help validate computational models of traumatic brain injury and to understand the factors that govern the mechanical response of the brain. Tagged magnetic resonance imaging is a powerful, noninvasive technique to track tissue motion in vivo which has been used to quantify brain deformation in live human subjects. However, these prior studies required from 72 to 144 head rotations to generate deformation data for a single image slice, precluding its use to investigate the entire brain in a single subject. Here, a novel method is introduced that significantly reduces temporal variability in the acquisition and improves the accuracy of displacement estimates. Optimization of the acquisition parameters in a gelatin phantom and three human subjects leads to a reduction in the number of rotations from 72 to 144 to as few as 8 for a single image slice. The ability to estimate accurate, well-resolved, fields of displacement and strain in far fewer repetitions will enable comprehensive studies of acceleration-induced deformation throughout the human brain in vivo. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Diffuse optical measurements of head and neck tumor hemodynamics for early prediction of chemoradiation therapy outcomes

    Science.gov (United States)

    Dong, Lixin; Kudrimoti, Mahesh; Irwin, Daniel; Chen, Li; Kumar, Sameera; Shang, Yu; Huang, Chong; Johnson, Ellis L.; Stevens, Scott D.; Shelton, Brent J.; Yu, Guoqiang

    2016-08-01

    This study used a hybrid near-infrared diffuse optical instrument to monitor tumor hemodynamic responses to chemoradiation therapy for early prediction of treatment outcomes in patients with head and neck cancer. Forty-seven patients were measured once per week to evaluate the hemodynamic status of clinically involved cervical lymph nodes as surrogates for the primary tumor response. Patients were classified into two groups: complete response (CR) (n=29) and incomplete response (IR) (n=18). Tumor hemodynamic responses were found to be associated with clinical outcomes (CR/IR), wherein the associations differed depending on human papillomavirus (HPV-16) status. In HPV-16 positive patients, significantly lower levels in tumor oxygenated hemoglobin concentration ([HbO2]) at weeks 1 to 3, total hemoglobin concentration at week 3, and blood oxygen saturation (StO2) at week 3 were found in the IR group. In HPV-16 negative patients, significantly higher levels in tumor blood flow index and reduced scattering coefficient (μs‧) at week 3 were observed in the IR group. These hemodynamic parameters exhibited significantly high accuracy for early prediction of clinical outcomes, within the first three weeks of therapy, with the areas under the receiver operating characteristic curves (AUCs) ranging from 0.83 to 0.96.

  2. Groundwater-surface water interaction along the Upper Biebrza River, Poland: a spatial-temporal approach with temperature, head and seepage measurements

    Science.gov (United States)

    Anibas, C.; Batelaan, O.; Verbeiren, B.; Buis, K.; Chormanski, J.; de Doncker, L.

    2010-12-01

    The knowledge of mechanisms of interaction of surface and groundwater in the hyporheic zone in rivers is essential for conserving, managing and restoring river adjacent wetlands and its habitats. Reliable estimation of groundwater-surface water exchange challenges hydrological sciences. A promising approach, overcoming limitations of individual methods, is the combination of different methodologies including flux estimates based on thermal measurements, piezometer nests, slug tests and seepage meters. In this contribution such a multi-methodology approach is tested for the Upper Biebrza River, Poland. Time series of thermal profiles are obtained for a period of 9 months. The thermal and physical soil properties show strong spatial and vertical heterogeneities typical for the peat soils of the area. Transient simulations with the numerical 1D heat transport model STRIVE were used to quantify the vertical advective fluxes in the riverbed allowing a first level investigation of groundwater-surface water exchange. The net exchange along the examined section during the 9 month is estimated as a 10.4 mm/d upward flux, which is evaluated as a relatively low intensity of groundwater seepage. Time series of both temperature and hydraulic head gradients were used to calculate hydraulic conductivities and to quantify transient groundwater-surface water exchanges for three locations. They indicated an exchange flux relatively relative stable in time only interrupted by peak values during flood events. Seepage meter measurements provided independent verification results. Interpolating calculated fluxes along the river with GIS techniques resulted in spatially distributed interaction maps. Sections of higher fluxes are statistically correlated to the proximity of the river to the morainic plateaus, which border the river alluvium. In sections where the river is central in the alluvium and relatively far away from the upland low or infiltrating conditions are obtained. This

  3. Hydraulic characterization of " Furcraea andina

    Science.gov (United States)

    Rivera-Velasquez, M. F.; Fallico, C.; Molinari, A.; Santillan, P.; Salazar, M.

    2012-04-01

    The present level of pollution, increasingly involving groundwaters, constitutes a serious risk for environment and human health. Therefore the remediation of saturated and unsaturated soils, removing pollutant materials through innovative and economic bio-remediation techniques is more frequently required. Recent studies on natural fiber development have shown the effectiveness of these fibers for removal of some heavy metals, due to the lignin content in the natural fibers which plays an important role in the adsorption of metal cations (Lee et al., 2004; Troisi et al., 2008; C. Fallico, 2010). In the context of remediation techniques for unsaturated and/or saturated zone, an experimental approach for the hydraulic characterization of the "Furcraea andina" (i.e., Cabuya Blanca) fiber was carried out. This fiber is native to Andean regions and grows easily in wild or cultivated form in the valleys and hillsides of Colombia, Ecuador, and Peru. Fibers of "Furcraea andina" were characterized by experimental tests to determine their hydraulic conductivity or permeability and porosity in order to use this medium for bioremediation of contaminated aquifer exploiting the physical, chemical and microbial capacity of natural fiber in heavy metal adsorption. To evaluate empirically the hydraulic conductivity, laboratory tests were carried out at constant head specifically on the fibers manually extracted. For these tests we used a flow cell (used as permeameter), containing the "Furcraea andina" fibers to be characterized, suitably connected by a tygon pipe to a Marriott's bottle, which had a plastic tube that allow the adjustment of the hydraulic head for different tests to a constant value. By this experiment it was also possible to identify relationships that enable the estimation of permeability as a function of density, i.e. of the compaction degree of the fibers. Our study was carried out for three values of hydraulic head (H), namely 10, 18, and 25 cm and for each

  4. Diamond-coated probe head for measurements in the deep SOL and beyond

    DEFF Research Database (Denmark)

    Schrittwieser, R.; Xu, G. S.; Yan, Ning

    We have tested two cylindrical graphite probe heads coated by a layer of electrically isolating UNCD (Ultra Nano-Crystalline Diamond) using a CVD (Chemical Vapour Deposition) method. The probe heads were mounted on the reciprocating probe manipulator of the Experimental Advanced Superconducting...... Tokamak (EAST) in Hefei, People's Republic of China. Transport parameters, plasma density, temperature, potential, as well as toroidal rotation near the separatrix were determined up to a distance of 15 mm inside the LCFS in high confinement regimes. A very important result was that the UNCD coating could...... also prevent the sputtering of graphite from the probe head and the subsequent coating of the BN isolation between probe pins and probe head by a layer of conductive graphite almost completely....

  5. Head and heart orientation: A measure of marketers' predisposition for ethical conduct

    National Research Council Canada - National Science Library

    Kochunny, C M; Rogers, Hudson P; Ogbuehi, Alphonso O

    1996-01-01

    .... An earlier study of marketing students is used for comparison. Akin to the results from the student study, the study demonstrates a marked bias amongst subjects for valuing qualities of the head...

  6. Trismus in head and neck cancer patients treated by telecobalt and effect of early rehabilitation measures

    OpenAIRE

    Sindhu Nagaraja; S Amrut Kadam; Karthikeyan Selvaraj; Iqbal Ahmed; Rajesh Javarappa

    2016-01-01

    Context: Trismus is one of the common late side effects of radiotherapy (RT) of head and neck cancers. It occurs in about 30% of patients treated by telecobalt. It, in turn, leads to significant morbidity, including malnutrition, difficulty in speaking, and compromised oral hygiene with severe psychosocial, and economic impacts. Aims: To determine the prevalence of trismus and its progression in patients who have received radical concurrent chemoradiation for head and neck cancer by teleco...

  7. The effect of measured and estimated soil hydraulic properties on simulated water regime in the analysis of grapevine adaptability to future climate

    Science.gov (United States)

    Bonfante, Antonello; Alfieri, Silvia Maria; Agrillo, Antonietta; Dragonetti, Giovanna; Mileti, Antonio; Monaco, Eugenia; De Lorenzi, Francesca

    2013-04-01

    In the last years many research works have been addressed to evaluate the impact of future climate on crop productivity and plant water use at different spatial scales (global, regional, field) by means of simulation models of agricultural crop systems. Most of these approaches use estimated soil hydraulic properties, through pedotransfer functions (PTF). This choice is related to soil data availability: soil data bases lack measured soil hydraulic properties, but generally they contain information that allow the application of PTF . Although the reliability of the predicted future climate scenarios cannot be immediately validated, we address to evaluate the effects of a simplification of the soil system by using PTF. Thus we compare simulations performed with measured soil hydraulic properties versus simulations carried out with estimated properties. The water regimes resulting from the two procedures are evaluated with respect to crop adaptability to future climate. In particular we will examine if the two procedures bring about different seasonal and spatial variations in the soil water regime patterns, and if these patterns influence adaptation options. The present case study uses the agro-hydrological model SWAP (soil-water-atmosphere and plant) and studies future adaptability of grapevine. The study area is a viticultural area of Southern Italy (Valle Telesina, BN) devoted to the production of high quality wines (DOC and DOCG), and characterized by a complex geomorphology and pedology. The future climate scenario (2021-2050) was constructed applying statistical downscaling techniques to GCMs scenarios. The moisture regime for 25 soils of the selected study area was calculated by means of SWAP model, using both measured and estimated soil hydraulic properties. In the simulation, the upper boundary conditions were derived from the regional climate scenarios. Unit gradient in soil water potential was set as lower boundary condition. Crop-specific input data and

  8. Temporal changes in hydraulic conductivity of sand porous media biofilters during wastewater infiltration due to biomat formation

    Science.gov (United States)

    Beach, Deborah N. H.; McCray, John E.; Lowe, Kathryn S.; Siegrist, Robert L.

    2005-09-01

    Porous media biofilters (PMBs) are commonly used to treat domestic wastewater. Biomats develop at the infiltrative surface of PMBs due to continued wastewater application and create an impedance to flow. The goal of this research is to quantify the temporal evolution of normalized biomat hydraulic conductivity ( Kbm/ bbm) and effective hydraulic conductivity ( Ke). Ke is the overall hydraulic conductivity of the infiltrative zone, including biomat and unsaturated media below the biomat. Research was conducted using eight one-dimensional (1D) sand columns with gravel-free and gravel-laden infiltrative surfaces. The columns were loaded at design rates of 100-200 cm/d for 20 weeks of column operation. The Ke values for these continuously loaded columns were determined from analyses of bromide-tracer tests, falling-head permeability tests, and volumetric water content measurements during biomat development. The reduction in the Ke due to biomat formation is due to two factors: reduced hydraulic conductivity of the thin biomat, and a reduced hydraulic conductivity of the subsoil due to development of a biomat-induced unsaturated flow regime. Unsaturated hydraulic conductivities of the subsoil below the biomat ( Kss) were estimated from capillary curves and water content measurements. For observed final biomat thicknesses (less than 1 cm), the biomat hydraulic conductivity, Kbm, is three orders of magnitude smaller than the unsaturated hydraulic conductivity ( Kss). However, the relatively large thickness of the vadose zone causes the Kss to be an important contributor to the overall Ke value. For these columns, the final Ke values were approximately two orders of magnitude smaller than the original value. Because the exact thickness of the biomat ( bbm) is unknown during the flow experiments, the hydraulic conductance of the biomat zone is presented using a normalized hydraulic conductivity function ( Kbm/ bbm). A similar Kbm/ bbm is reached regardless of wastewater

  9. Measurement of unsaturated hydraulic properties and evaluation of property-transfer models for deep sedimentary interbeds, Idaho National Laboratory, Idaho

    Science.gov (United States)

    Perkins, Kimberlie; Johnson, Brittany D.; Mirus, Benjamin B.

    2014-01-01

    Operations at the Idaho National Laboratory (INL) have the potential to contaminate the underlying Eastern Snake River Plain (ESRP) aquifer. Methods to quantitatively characterize unsaturated flow and recharge to the ESRP aquifer are needed to inform water-resources management decisions at INL. In particular, hydraulic properties are needed to parameterize distributed hydrologic models of unsaturated flow and transport at INL, but these properties are often difficult and costly to obtain for large areas. The unsaturated zone overlying the ESRP aquifer consists of alternating sequences of thick fractured volcanic rocks that can rapidly transmit water flow and thinner sedimentary interbeds that transmit water much more slowly. Consequently, the sedimentary interbeds are of considerable interest because they primarily restrict the vertical movement of water through the unsaturated zone. Previous efforts by the U.S. Geological Survey (USGS) have included extensive laboratory characterization of the sedimentary interbeds and regression analyses to develop property-transfer models, which relate readily available physical properties of the sedimentary interbeds (bulk density, median particle diameter, and uniformity coefficient) to water retention and unsaturated hydraulic conductivity curves.

  10. Flow coefficient measurements for an engine cylinder head under transient flow conditions with continuous valve lift change

    OpenAIRE

    Daesan Oh; Choong Hoon Lee

    2015-01-01

    A flow coefficient measurement system which is operated under an unsteady intake flow condition in the intake port of a diesel engine cylinder head was developed. In order to determine the actual engine intake flow condition, the valve lift of the intake valve, whose rod is in contact with the camshaft, is varied continuously by rotating the camshaft directly. While varying the rotation speed of the camshaft, the flow coefficients were calculated by measuring various sensor signals, in this c...

  11. Laboratory-Measured and Property-Transfer Modeled Saturated Hydraulic Conductivity of Snake River Plain Aquifer Sediments at the Idaho National Laboratory, Idaho

    Science.gov (United States)

    Perkins, Kim S.

    2008-01-01

    Sediments are believed to comprise as much as 50 percent of the Snake River Plain aquifer thickness in some locations within the Idaho National Laboratory. However, the hydraulic properties of these deep sediments have not been well characterized and they are not represented explicitly in the current conceptual model of subregional scale ground-water flow. The purpose of this study is to evaluate the nature of the sedimentary material within the aquifer and to test the applicability of a site-specific property-transfer model developed for the sedimentary interbeds of the unsaturated zone. Saturated hydraulic conductivity (Ksat) was measured for 10 core samples from sedimentary interbeds within the Snake River Plain aquifer and also estimated using the property-transfer model. The property-transfer model for predicting Ksat was previously developed using a multiple linear-regression technique with bulk physical-property measurements (bulk density [pbulk], the median particle diameter, and the uniformity coefficient) as the explanatory variables. The model systematically underestimates Ksat,typically by about a factor of 10, which likely is due to higher bulk-density values for the aquifer samples compared to the samples from the unsaturated zone upon which the model was developed. Linear relations between the logarithm of Ksat and pbulk also were explored for comparison.

  12. A coupled hydrological-hydraulic flood inundation model calibrated using post-event measurements and integrated uncertainty analysis in a poorly gauged Mediterranean basin

    Science.gov (United States)

    Hdeib, Rouya; Abdallah, Chadi; Moussa, Roger; Colin, Francois

    2017-04-01

    Developing flood inundation maps of defined exceedance probabilities is required to provide information on the flood hazard and the associated risk. A methodology has been developed to model flood inundation in poorly gauged basins, where reliable information on the hydrological characteristics of floods are uncertain and partially captured by the traditional rain-gauge networks. Flood inundation is performed through coupling a hydrological rainfall-runoff (RR) model (HEC-HMS) with a hydraulic model (HEC-RAS). The RR model is calibrated against the January 2013 flood event in the Awali River basin, Lebanon (300 km2), whose flood peak discharge was estimated by post-event measurements. The resulting flows of the RR model are defined as boundary conditions of the hydraulic model, which is run to generate the corresponding water surface profiles and calibrated against 20 post-event surveyed cross sections after the January-2013 flood event. An uncertainty analysis is performed to assess the results of the models. Consequently, the coupled flood inundation model is simulated with design storms and flood inundation maps are generated of defined exceedance probabilities. The peak discharges estimated by the simulated RR model were in close agreement with the results from different empirical and statistical methods. This methodology can be extended to other poorly gauged basins facing common stage-gauge failure or characterized by floods with a stage exceeding the gauge measurement level, or higher than that defined by the rating curve.

  13. Measurement of Head Impact Due to Standing Fall in Adults Using Anthropomorphic Test Dummies.

    Science.gov (United States)

    Hajiaghamemar, Marzieh; Seidi, Morteza; Ferguson, James R; Caccese, Vincent

    2015-09-01

    The kinematics and kinetics of head impact due to a standing fall onto a hard surface are summarized. Head injury due to impact from falls represents a significant problem, especially for older individuals. When the head is left unprotected during a fall, the impact severity can be high enough to cause significant injury or even death. To ascertain the range of head impact parameters, the dynamic response was captured for the pedestrian version of the 5th percentile female and 50th percentile male Hybrid III anthropomorphic test dummies as they were dropped from a standing position with different initial postures. Five scenarios of falls were considered including backward falls with/without hip flexion, forward falls with/without knee flexion and lateral falls. The results show that the head impact parameters are dependent on the fall scenario. A wide range of impact parameters was observed in 107 trials. The 95% prediction interval for the peak translational acceleration, peak angular acceleration, peak force, impact translational velocity and peak angular velocity are 146-502 g, 8.8-43.3 krad/s(2), 3.9-24.5 kN, 2.02-7.41 m/s, and 12.9-70.3 rad/s, respectively.

  14. Measuring water quality from individual fractures in open wellbores using hydraulic isolation and the dissolved oxygen alteration method

    Science.gov (United States)

    Vitale, Sarah A.; Robbins, Gary A.

    2017-08-01

    This study describes a low-cost method for sampling individual fractures in open wellbores in crystalline bedrock utilizing naturally occurring flow conditions in the well. The method entails using the dissolved oxygen alteration method (DOAM) to identify transmissive fractures and vertical flow direction. After obtaining information about relative hydraulic gradients, flow direction in the well is modified using a single control pump to isolate fractures of interest for sampling. Additional dissolved oxygen, injected during the DOAM procedure, serves as a tracer to ensure the water quality in the sampling zone is characteristic of the fracture of interest by requiring a tracer-free zone prior to sampling. Sampling procedures are described conceptually for nine bedrock wells with varying flow conditions containing one, two, or three transmissive inflowing fractures. The method was demonstrated in two crystalline bedrock wells containing one and two transmissive inflowing fractures.

  15. Variation in repeated mouth-opening measurements in head and neck cancer patients with and without trismus.

    Science.gov (United States)

    Jager-Wittenaar, H; Dijkstra, P U; Vissink, A; van Oort, R P; Roodenburg, J L N

    2009-01-01

    Trismus after head and neck cancer treatment may severely limit mandibular functioning. Interventions aimed at reducing trismus can only be evaluated when the amount of variation associated with these measurements is known. The aim of this study was to analyse the variation in mouth-opening measurements in patients treated for head and neck cancer, with and without trismus. Maximal mouth opening was measured in 120 patients in two sessions of three repeated measurements by one observer. To analyse the influence of interobserver variation on mouth-opening measurements a subgroup of 30 patients was measured by a second observer. The standard deviation of the six measurements per patient was used as the variation in measurements of maximal mouth opening. No significant difference was found in maximal mouth opening in patients with (n=33) or without (n=87) trismus. The interobserver intraclass correlation coefficient (ICC) was 0.98. Intraobserver ICC and intersession ICC reliabilities both were 0.99. The variation in the mean values of the three measurements was only slightly smaller than the variation of the single measurements. Variation in maximal mouth opening in patients with trismus does not differ from variation in maximal mouth opening in patients without trismus. Interobserver variation is limited.

  16. Validity of the Wonderlic Personnel Test as a brief measure of intelligence in individuals referred for evaluation of head injury.

    Science.gov (United States)

    Saltzman, J; Strauss, E; Hunter, M; Spellacy, F

    1998-10-01

    Some have argued that the Wonderlic Personnel Test (WPT) may represent a brief and efficient measure of intellectual functioning (e.g., Dodrill, 1980). The present study investigated the validity of the WPT as such a measure, in individuals with head injury. The findings suggested that, although the WPT showed relatively high agreement with the Wechsler Adult Intelligence Scale-Revised (WAIS-R) in the whole group, it did not have good agreement with WAIS-R scores on an individual case basis. Since clinical practice typically seeks to evaluate individual performance, it is suggested that the WPT is not a suitable tool for psychological assessment of individuals with known or suspected head injury.

  17. Cleveland Clinic intelligent mouthguard: a new technology to accurately measure head impact in athletes and soldiers

    Science.gov (United States)

    Bartsch, Adam; Samorezov, Sergey

    2013-05-01

    Nearly 2 million Traumatic Brain Injuries (TBI) occur in the U.S. each year, with societal costs approaching $60 billion. Including mild TBI and concussion, TBI's are prevalent in soldiers returning from Iraq and Afghanistan as well as in domestic athletes. Long-term risks of single and cumulative head impact dosage may present in the form of post traumatic stress disorder (PTSD), depression, suicide, Chronic Traumatic Encephalopathy (CTE), dementia, Alzheimer's and Parkinson's diseases. Quantifying head impact dosage and understanding associated risk factors for the development of long-term sequelae is critical toward developing guidelines for TBI exposure and post-exposure management. The current knowledge gap between head impact exposure and clinical outcomes limits the understanding of underlying TBI mechanisms, including effective treatment protocols and prevention methods for soldiers and athletes. In order to begin addressing this knowledge gap, Cleveland Clinic is developing the "Intelligent Mouthguard" head impact dosimeter. Current testing indicates the Intelligent Mouthguard can quantify linear acceleration with 3% error and angular acceleration with 17% error during impacts ranging from 10g to 174g and 850rad/s2 to 10000rad/s2, respectively. Correlation was high (R2 > 0.99, R2 = 0.98, respectively). Near-term development will be geared towards quantifying head impact dosages in vitro, longitudinally in athletes and to test new sensors for possible improved accuracy and reduced bias. Long-term, the IMG may be useful to soldiers to be paired with neurocognitive clinical data quantifying resultant TBI functional deficits.

  18. Vibrations of hydraulic pump and their solution

    OpenAIRE

    Dobšáková Lenka; Nováková Naděžda; Habán Vladimír; Hudec Martin; Jandourek Pavel

    2017-01-01

    The vibrations of hydraulic pump and connected pipeline system are very problematic and often hardly soluble. The high pressure pulsations of hydraulic pump with the double suction inlet are investigated. For that reason the static pressure and accelerations are measured. The numerical simulations are carried out in order to correlate computed data with experimental ones and assess the main source of vibrations. Consequently the design optimization of the inner hydraulic part of pump is done ...

  19. A framework for geometry acquisition, 3-D printing, simulation, and measurement of head-related transfer functions with a focus on hearing-assistive devices

    DEFF Research Database (Denmark)

    Harder, Stine; Paulsen, Rasmus Reinhold; Larsen, Martin

    2016-01-01

    of a three-dimensional (3D) head model for acquisition of individual HRTFs. Two aspects were investigated; whether a 3D-printed model can replace measurements on a human listener and whether numerical simulations can replace acoustic measurements. For this purpose, HRTFs were acoustically measured for four...... human listeners and for a 3D printed head model of one of these listeners. Further, HRTFs were simulated by applying the finite element method to the 3D head model. The monaural spectral features and spectral distortions were very similar between re-measurements and between human and printed...

  20. Accelerometer Measurement of Head Movement During Laparoscopic Surgery as a Tool to Evaluate Skill Development of Surgeons.

    Science.gov (United States)

    Viriyasiripong, Sarayuth; Lopez, Asis; Mandava, Sree Harsha; Lai, Weil R; Mitchell, Gregory C; Boonjindasup, Aaron; Powers, Mary K; Silberstein, Jonathan L; Lee, Benjamin R

    2016-01-01

    To detect and measure surgeons' head movement during laparoscopic simulator performance to determine whether expert surgeons have economy of motion in their head movement, including change of direction, compared with intermediate and novice surgeons. We investigated head movement as an objective tool for assessment of laparoscopic surgical skill and its potential use for assessing novice surgeons' progress on the learning curve. After obtaining institutional review board approval, medical students, urology residents, and attending staff surgeons from an academic institution were recruited. Participants were grouped by level of experience and performed tasks on the Electronic Data Generation for Evaluation laparoscopic simulator. Surgeons wore a commercially available wireless electroencephalogram monitor as a flexible, adjustable, and lightweight headband with 7 sensors-2 forehead sensors, 2 ear sensors, and 3 reference sensors. The headband incorporates a 3-axis accelerometer enabling head movement quantification. A variance analysis was used to compare the average head movement acceleration data between each group. Tulane University Medical Center, New Orleans, LA, an academic medical center and the principal teaching hospital for Tulane University School of Medicine. A total of following 19 participants were recruited for the study and stratified by surgical experience into novice (n = 6), intermediate (n = 9), and expert (n = 4) laparoscopy groups: 6 medical students, 9 urology residents (postgraduate years 1 to5), and 4 attending urologists, respectively. Analysis of the average acceleration rate of head movement showed statistically significant differences among groups on both the vertical axis (p = 0.006) and horizontal axis (p = 0.018) in the laparoscopic suturing task. This demonstrated the ability to distinguish between experts and novice laparoscopic surgeons. The average acceleration among groups did not demonstrate statistical significance on the

  1. Gravity-Driven Hydraulic Fractures

    Science.gov (United States)

    Germanovich, L. N.; Garagash, D.; Murdoch, L. C.; Robinowitz, M.

    2014-12-01

    This study is motived by a new method for disposing of nuclear waste by injecting it as a dense slurry into a hydraulic fracture that grows downward to great enough depth to permanently isolate the waste. Disposing of nuclear waste using gravity-driven hydraulic fractures is mechanically similar to the upward growth of dikes filled with low density magma. A fundamental question in both applications is how the injected fluid controls the propagation dynamics and fracture geometry (depth and breadth) in three dimensions. Analog experiments in gelatin [e.g., Heimpel and Olson, 1994; Taisne and Tait, 2009] show that fracture breadth (the short horizontal dimension) remains nearly stationary when the process in the fracture "head" (where breadth is controlled) is dominated by solid toughness, whereas viscous fluid dissipation is dominant in the fracture tail. We model propagation of the resulting gravity-driven (buoyant or sinking), finger-like fracture of stationary breadth with slowly varying opening along the crack length. The elastic response to fluid loading in a horizontal cross-section is local and can be treated similar to the classical Perkins-Kern-Nordgren (PKN) model of hydraulic fracturing. The propagation condition for a finger-like crack is based on balancing the global energy release rate due to a unit crack extension with the rock fracture toughness. It allows us to relate the net fluid pressure at the tip to the fracture breadth and rock toughness. Unlike the PKN fracture, where breadth is known a priori, the final breadth of a finger-like fracture is a result of processes in the fracture head. Because the head is much more open than the tail, viscous pressure drop in the head can be neglected leading to a 3D analog of Weertman's hydrostatic pulse. This requires relaxing the local elasticity assumption of the PKN model in the fracture head. As a result, we resolve the breadth, and then match the viscosity-dominated tail with the 3-D, toughness

  2. Direct measurement of the field from a magnetic recording head using an InAs Hall sensor on a contact write/read tester

    Science.gov (United States)

    Gokemeijer, N. J.; Clinton, T. W.; Crawford, T. M.; Johnson, Mark

    2005-04-01

    At 1 Tbit/in2 areal density magnetic recording dimensions, reliable magnetic field metrology does not exist. One technique to map the spatial profile of the magnetic field of a write head is to use a contact read/write tester. A magnetic recording head is brought into contact with a Hall sensor, and is subsequently scanned with nm resolution. For a 300 nm track width longitudinal recording head, the magnetic field of the head was mapped. Measurements include the down track field gradient and cross-track field profile and the current-field transfer curve. These results suggest this technique offers a viable write field metrology.

  3. Direct measurement of the field from a magnetic recording head using an InAs Hall sensor on a contact write/read tester

    Energy Technology Data Exchange (ETDEWEB)

    Gokemeijer, N.J. [Seagate Research, 1251 Waterfront Place, Pittsburgh, PA 15222 (United States)]. E-mail: nils.gokemeijer@seagate.com; Clinton, T.W. [Seagate Research, 1251 Waterfront Place, Pittsburgh, PA 15222 (United States); Crawford, T.M. [Seagate Research, 1251 Waterfront Place, Pittsburgh, PA 15222 (United States); Johnson, Mark [Naval Research Labs, 4555 Overlook Ave. S.W., Washington, DC 20375 (United States)

    2005-04-15

    At 1 Tbit/in{sup 2} areal density magnetic recording dimensions, reliable magnetic field metrology does not exist. One technique to map the spatial profile of the magnetic field of a write head is to use a contact read/write tester. A magnetic recording head is brought into contact with a Hall sensor, and is subsequently scanned with nm resolution. For a 300 nm track width longitudinal recording head, the magnetic field of the head was mapped. Measurements include the down track field gradient and cross-track field profile and the current-field transfer curve. These results suggest this technique offers a viable write field metrology.

  4. Long-term continuous atmospheric CO2 measurements at Baring Head, New Zealand

    Directory of Open Access Journals (Sweden)

    S. E. Nichol

    2012-12-01

    Full Text Available We present descriptions of the in situ instrumentation, calibration procedures, intercomparison efforts, and data filtering methods used in a 39-yr record of continuous atmospheric carbon dioxide (CO2 observations made at Baring Head, New Zealand. Located on the southern coast of the North Island, Baring Head is exposed to extended periods of strong air flow from the south with minimal terrestrial influence resulting in low CO2 variability. The site is therefore well suited for sampling air masses that are representative of the Southern Ocean region. Instrumental precision is better than 0.015 ppm (1-σ on 1-Hz values. Comparisons to over 600 co-located flask samples, as well as laboratory based flask and cylinder comparison exercises, suggest that over recent decades compatibility with respect to the Scripps Institution of Oceanography (SIO and World Meteorological Organisation (WMO CO2 scales has been 0.3 ppm or better.

  5. A Reward-Based Behavioral Platform to Measure Neural Activity during Head-Fixed Behavior.

    Science.gov (United States)

    Micallef, Andrew H; Takahashi, Naoya; Larkum, Matthew E; Palmer, Lucy M

    2017-01-01

    Understanding the neural computations that contribute to behavior requires recording from neurons while an animal is behaving. This is not an easy task as most subcellular recording techniques require absolute head stability. The Go/No-Go sensory task is a powerful decision-driven task that enables an animal to report a binary decision during head-fixation. Here we discuss how to set up an Ardunio and Python based platform system to control a Go/No-Go sensory behavior paradigm. Using an Arduino micro-controller and Python-based custom written program, a reward can be delivered to the animal depending on the decision reported. We discuss the various components required to build the behavioral apparatus that can control and report such a sensory stimulus paradigm. This system enables the end user to control the behavioral testing in real-time and therefore it provides a strong custom-made platform for probing the neural basis of behavior.

  6. A 15 year record of high-frequency, in situ measurements of hydrogen at Mace Head, Ireland

    Directory of Open Access Journals (Sweden)

    A. Grant

    2010-02-01

    Full Text Available Continuous high-frequency measurements of atmospheric molecular hydrogen have been made at Mace Head atmospheric research station on the west coast of Ireland from March 1994 to December 2008. The presented data provides information on long term trends and seasonal cycles of hydrogen in background northern hemispheric air. Individual measurements have been sorted using a Lagrangian dispersion model to separate clean background air from regionally polluted European air masses and those transported from southerly latitudes. No significant trend was observed in background northern hemispheric air over the 15 year record, elevations in yearly means were accounted for from large scale biomass burning events. Seasonal cycles show the expected pattern with maxima in spring and minima in late autumn. The mean hydrogen mole fraction in baseline northern hemispheric air was found to be 500.1 ppb. Air transported from southerly latitudes showed an elevation from baseline mean of 11.0 ppb, reflecting both the latitudinal gradient of hydrogen, with higher concentrations in the Southern Hemisphere, and the photochemical source of hydrogen from low northern latitudes. European polluted air masses arriving at Mace Head showed mean elevation of 5.3 ppb from baseline air masses, reflecting hydrogen's source from primary emissions like fossil fuel combustion. Forward modelling of transport of hydrogen to Mace Head suggests that the ratio of hydrogen to carbon monoxide in primary emissions is considerably less in non-traffic sources than traffic sources.

  7. Ethanol consumption impairs vestibulo-ocular reflex function measured by the video head impulse test and dynamic visual acuity.

    Science.gov (United States)

    Roth, Thomas N; Weber, Konrad P; Wettstein, Vincent G; Marks, Guy B; Rosengren, Sally M; Hegemann, Stefan C A

    2014-01-01

    Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38 per mil. All tests were normal at baseline. VOR gain measured by vHIT decreased by 25% at the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement.

  8. A five year record of high-frequency in situ measurements of non-methane hydrocarbons at Mace Head, Ireland

    Directory of Open Access Journals (Sweden)

    A. Grant

    2011-02-01

    Full Text Available Continuous high-frequency in situ measurements of a range of non-methane hydrocarbons have been made at Mace Head since January 2005. Mace Head is a background Northern Hemispheric site situated on the eastern edge of the Atlantic. Five year measurements (2005–2009 of eleven non-methane hydrocarbons, namely C2–C5 alkanes, benzene, toluene, ethyl-benzene and the xylenes, have been separated into baseline Northern Hemispheric and European polluted air masses, among other sectors. Seasonal cycles in baseline Northern Hemispheric air masses and European polluted air masses arriving at Mace Head have been studied. Baseline air masses show a broad summer minima between June and September for shorter lived species, longer lived species show summer minima in July/August. All species displayed a winter maxima in February. European air masses showed baseline elevated mole fractions for all non-methane hydrocarbons, largest elevations (of up to 360 ppt for ethane maxima from baseline data were observed in winter maxima, with smaller elevations observed during the summer. Analysis of temporal trends using the Mann-Kendall test showed small (<6%/year but statistically significant decreases in the butanes, i-pentane and o-xylene between 2005 and 2009 in European air. Toluene was found to have an increasing trend of 34%/year in European air. No significant trends were found for any species in baseline air.

  9. Refining Measurement of Social Cognitive Theory Factors Associated with Exercise Adherence in Head and Neck Cancer Patients.

    Science.gov (United States)

    Rogers, Laura Q; Fogleman, Amanda; Verhulst, Steven; Bhugra, Mudita; Rao, Krishna; Malone, James; Robbs, Randall; Robbins, K Thomas

    2015-01-01

    Social cognitive theory (SCT) measures related to exercise adherence in head and neck cancer (HNCa) patients were developed. Enrolling 101 HNCa patients, psychometric properties and associations with exercise behavior were examined for barriers self-efficacy, perceived barriers interference, outcome expectations, enjoyment, and goal setting. Cronbach's alpha ranged from.84 to.95; only enjoyment demonstrated limited test-retest reliability. Subscales for barriers self-efficacy (motivational, physical health) and barriers interference (motivational, physical health, time, environment) were identified. Multiple SCT constructs were cross-sectional correlates and prospective predictors of exercise behavior. These measures can improve the application of the SCT to exercise adherence in HNCa patients.

  10. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...... of the laws of physics on the system. The unknown (or uncertain) parameters are estimated with Maximum Likelihood (ML) parameter estimation. The identified model has been evaluated by comparing the measurements with simulation of the model. The identified model was much more capable of describing the dynamics...... of the system than the deterministic model....

  11. A tensor approach to the estimation of hydraulic conductivities in ...

    African Journals Online (AJOL)

    2006-07-03

    Jul 3, 2006 ... The HC values computed from the data measured on the weathered or ... Keywords: hydraulic conductivity tensor, roughness, combined stress, hydraulic aperture, Table Mountain ... the anisotropic nature of studied media.

  12. HYDRAULICS, LOUISA COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic analysis for estimating flood stages for a flood insurance study. It...

  13. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  14. DISCONTINUOUS FLOW OF TURBID DENSITY CURRENTS Ⅱ. INTERNAL HYDRAULIC JUMP

    Institute of Scientific and Technical Information of China (English)

    Jiahua FAN

    2005-01-01

    Traveling and stationary internal hydraulic jumps in density currents with positive or negative entrainment coefficients were analyzed based on simple assumptions. An expression of internal hydraulic jumps with entrainment coefficients was derived. Experimental data, published in literature, of stationary internal hydraulic jumps in turbid, thermal and saline density currents including measured values of water entrainment were used to compare with theory. Comparison was also made of traveling internal hydraulic jumps between measured data and theory.

  15. Multivariate head injury threshold measures for various sized children seated behind vehicle seats in rear impacts.

    Science.gov (United States)

    Saczalski, Kenneth; Sances, Anthony; Kumaresan, Srirangam; Pozzi, Mark; Saczalski, Todd; Burton, J L; Lewis, P

    2004-01-01

    Government recommendations to place children into the rear areas of motor vehicles to avoid airbag induced injuries have been complicated by the fact that most adult occupied front seats will collapse into the rear area during rear-impacts, and thus pose another potentially serious injury hazard to rear-seated children. Many variables affect whether or not a front seat occupant will collapse into the rear child, and whether that interaction could be injurious to the child. For instance, the severity of rear impact, coupled with front and rear occupant sizes (mass and stature), and the level of front seat strength, all interrelate to influence whether or not a rear seated child is likely to be impacted and possibly injured. The most common types of child injuries in these instances are head and chest injuries. In this study, a "high-low" experimental method was employed with a multi-level "factorial analysis" technique to study "multivariate" biomechanics of child head injury potential determined from rear-seated 3 and 6 year-old child surrogates in different types of vehicle bodies mounted to a sled system. The sled-buck systems were towed rearward into crushable barriers that matched the crash pulses of the vehicle types being tested. Various sizes of adult surrogates (i.e. 50 kg up to 110 kg), seated in both the "typical" low strength "single recliner" collapsing type front seat (i.e. 3.2 kN) and a much stronger "belt-integrated" seat design (i.e. up to 14.5 kN), were tested in the two different "sled body-buck" set-ups at various impact levels (i.e. 22.5 to 50 kph). One set-up used a popular minivan vehicle body with "built-in booster" seats for the 3 year-old. The other used a 4-door family sedan vehicle body with the 6 year-old in a standard rear bench seat. The parameters of the tests enabled the experimental data to be combined into polynomial "head injury" functions of the independent variables so the "likelihood" of rear child head-injury potential could

  16. 修筑寒区小型水利工程的经验回顾%A Review of Experience in Constructing Low-head Hydraulic Projects in Permafrost Regions

    Institute of Scientific and Technical Information of China (English)

    Rudolf V. Zhang

    2004-01-01

    The paper provides a review of experience with the construction of hydraulic projects in the permafrost regions. Principles for construction, operation and maintenance of earth dams are refined and formulated. High priority needs for improving the stability of structures are identified.

  17. The unsaturated hydraulic characteristics of the Bandelier Tuff

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, D.B.; Gallaher, B.M.

    1995-09-01

    This report summarizes the physical and, unsaturated hydraulic properties of the Bandelier Tuff determined from laboratory measurements made on core samples collected at Los Alamos National Laboratory. We fit new van Genuchten-type moisture retention curves to this data, which was categorized according to member of the Bandelier Tuff and subunit of the Tshirege Member. Reasonable consistency was observed for hydraulic properties and retention curves within lithologic units, while distinct differences were observed for those properties between units. With the moisture retention data, we constructed vertical profiles of in situ matric suction and hydraulic head. These profiles give an indication of the likely direction of liquid water movement within the unsaturated zone and allow comparison of core-scale and field-scale estimates of water flow and solute transport parameters. Our core-derived transport velocities are much smaller than values estimated from tritium, Cl, and NO{sub 3} contamination found recently in boreholes. The contaminant tracer-derived transport velocities from Los Alamos Canyon are greater than corederived values found for the Otowi Member, and for Mortandad Canyon, greater than core-derived values for that borehole. The significant difference found for Mortandad Canyon suggests that fracture or other fast-path transport may be important there. The relatively small difference between observed and predicted velocities at Los Alamos Canyon may mean that vadose zone transport there occurs by unsaturated matrix flow.

  18. On the Hydraulics of Flowing Horizontal Wells

    Science.gov (United States)

    Bian, A.; Zhan, H.

    2003-12-01

    A flowing horizontal well is a special type of horizontal well that does not have pumping/injecting facility. The discharge rate of a flowing horizontal well is controlled by the hydraulic gradient between the aquifer and the well and it generally varies with time if the hydraulic head of the aquifer is transient. This type of well has been used in landslide control, mining dewatering, water table control, underground water transportation through a horizontal tunnel, agricultural water drainage, and other applications. Flowing horizontal wells have quite different hydrodynamic characteristics from horizontal wells with fixed pumping or injecting rates because their discharge rates are functions of the aquifer hydraulic heads (Zhan et al, 2001; Zhan and Zlotnik, 2002). Hydraulics of flowing horizontal wells have rarely been studied although the hydraulics of flowing vertical wells have been extensively investigated before. The purpose of this paper is to obtain analytical solutions of groundwater flow to a flowing horizontal-well in a confined aquifer, in a water table aquifer without precipitation, and in a water table aquifer with precipitation. The functions of the flowing horizontal well discharge rates versus time will be obtained under above mentioned different aquifer conditions. The relationships of the aquifer hydraulic heads versus the discharge rates of the well will be investigated. The rate of water table decline due to the dewatering of the well will also be computed, and this solution is particularly useful for landslide control and mining dewatering. The theoretical solutions will be compared with results of experiments that will be conducted in the hydrological laboratory at Texas A&M University. Reference: Zhan, H., Wang, L.V., and Park, E, On the horizontal well pumping tests in the anisotropic confined aquifers, J. hydrol., 252, 37-50, 2001. Zhan, H., and Zlotnik, V. A., Groundwater flow to a horizontal or slanted well in an unconfined aquifer

  19. Process improvement and cost reduction utilizing a fully automated CD SEM for thin film head pole 2 resist measurements

    Science.gov (United States)

    Knutrud, Paul C.; Newcomb, Robert M.

    1996-05-01

    Thin film head (TFH) manufacturers are constantly striving to improve process control, eliminate scrap material and reduce the total cost of manufacturing their devices. Successful measurement and control of the Pole 2 Resist structure is a critical component of the TFH process which directly impacts disk drive performance, reliability and final product cost. Until recently, white light optical metrology systems have been the only option for measuring the Pole 2 structures. However, recent advances in TFH process technology have resulted in aspect ratios up to 10:1 which has limited the ability of the white light optical metrology systems. IVS has developed a unique metrology solution to image and measure these high aspect ratio structures utilizing the IVS-200TM CD SEM. This technology provides state of the art measurement performance for repeatability and stability which in turn has provided manufacturers with the ability to monitor the Pole 2 process and reap both technical and financial benefits.

  20. A Reward-Based Behavioral Platform to Measure Neural Activity during Head-Fixed Behavior

    Directory of Open Access Journals (Sweden)

    Andrew H. Micallef

    2017-05-01

    Full Text Available Understanding the neural computations that contribute to behavior requires recording from neurons while an animal is behaving. This is not an easy task as most subcellular recording techniques require absolute head stability. The Go/No-Go sensory task is a powerful decision-driven task that enables an animal to report a binary decision during head-fixation. Here we discuss how to set up an Ardunio and Python based platform system to control a Go/No-Go sensory behavior paradigm. Using an Arduino micro-controller and Python-based custom written program, a reward can be delivered to the animal depending on the decision reported. We discuss the various components required to build the behavioral apparatus that can control and report such a sensory stimulus paradigm. This system enables the end user to control the behavioral testing in real-time and therefore it provides a strong custom-made platform for probing the neural basis of behavior.

  1. Measurement and correction of microscopic head motion during magnetic resonance imaging of the brain.

    Directory of Open Access Journals (Sweden)

    Julian Maclaren

    Full Text Available Magnetic resonance imaging (MRI is a widely used method for non-invasive study of the structure and function of the human brain. Increasing magnetic field strengths enable higher resolution imaging; however, long scan times and high motion sensitivity mean that image quality is often limited by the involuntary motion of the subject. Prospective motion correction is a technique that addresses this problem by tracking head motion and continuously updating the imaging pulse sequence, locking the imaging volume position and orientation relative to the moving brain. The accuracy and precision of current MR-compatible tracking systems and navigator methods allows the quantification and correction of large-scale motion, but not the correction of very small involuntary movements in six degrees of freedom. In this work, we present an MR-compatible tracking system comprising a single camera and a single 15 mm marker that provides tracking precision in the order of 10 m and 0.01 degrees. We show preliminary results, which indicate that when used for prospective motion correction, the system enables improvement in image quality at both 3 T and 7 T, even in experienced and cooperative subjects trained to remain motionless during imaging. We also report direct observation and quantification of the mechanical ballistocardiogram (BCG during simultaneous MR imaging. This is particularly apparent in the head-feet direction, with a peak-to-peak displacement of 140 m.

  2. Filtering methods in tidal-affected groundwater head measurements: Application of harmonic analysis and continuous wavelet transform

    Science.gov (United States)

    Sánchez-Úbeda, Juan Pedro; Calvache, María Luisa; Duque, Carlos; López-Chicano, Manuel

    2016-11-01

    A new methodology has been developed to obtain tidal-filtered time series of groundwater levels in coastal aquifers. Two methods used for oceanography processing and forecasting of sea level data were adapted for this purpose and compared: HA (Harmonic Analysis) and CWT (Continuous Wavelet Transform). The filtering process is generally comprised of two main steps: the detection and fitting of the major tide constituents through the decomposition of the original signal and the subsequent extraction of the complete tidal oscillations. The abilities of the optional HA and CWT methods to decompose and extract the tidal oscillations were assessed by applying them to the data from two piezometers at different depths close to the shoreline of a Mediterranean coastal aquifer (Motril-Salobreña, SE Spain). These methods were applied to three time series of different lengths (one month, one year, and 3.7 years of hourly data) to determine the range of detected frequencies. The different lengths of time series were also used to determine the fit accuracies of the tidal constituents for both the sea level and groundwater heads measurements. The detected tidal constituents were better resolved with increasing depth in the aquifer. The application of these methods yielded a detailed resolution of the tidal components, which enabled the extraction of the major tidal constituents of the sea level measurements from the groundwater heads (e.g., semi-diurnal, diurnal, fortnightly, monthly, semi-annual and annual). In the two wells studied, the CWT method was shown to be a more effective method than HA for extracting the tidal constituents of highest and lowest frequencies from groundwater head measurements.

  3. Thermal Hydraulic Stability in a Coaxial Thermosyphon

    Institute of Scientific and Technical Information of China (English)

    YANG Jianhui; LU Wenqiang; LI Qing; LI Qiang; ZHOU Yuan

    2005-01-01

    The heat transfer and thermal hydraulic stability in a two-phase thermosyphon with coaxial riser and down-comer has been experimentally investigated and theoretically analyzed to facilitate its application in cold neutron source. The flow in a coaxial thermosyphon was studied experimentally for a variety of heating rates, transfer tube lengths, charge capacities, and area ratios. A numerical analysis of the hydraulic balance between the driving pressure head and the resistance loss has also been performed. The results show that the presented coaxial thermosyphon has dynamic performance advantages relative to natural circulation in a boiling water reactor.

  4. A γ-ray telescope for on-line measurements of low boron concentrations in a head phantom for BNCT

    Science.gov (United States)

    Verbakel, W. F. A. R.; Stecher-Rasmussen, F.

    1997-02-01

    In Boron Neutron Capture Therapy the 10B(n, α)7 Li reaction is used to create a tumour-destructing field of high Linear Energy Transfer (LET) particles. The therapy requires a high boron concentration in the tumour and a low boron concentration in the healthy tissue. The boron neutron capture reaction is accompanied by the emission of a photon of energy 478 keV. It is investigated whether measuring of these photons can serve as a tool to determine the boron concentration during therapy in the tumour as well as in the healthy tissue. Such a measurement is complicated by the presence of a large background photon field. To study the feasibility, an experimental configuration has been designed at a test facility of the Low-Flux Reactor (LFR). The LFR provides an epithermal neutron beam for irradiation of a head phantom which simulates a human head with a tumour. This paper shows that the reconstruction of the position and the size of the tumour as well as the ratio of the boron concentrations appeared to be possible. In a second stage it is shown that these measurements can be expanded to experiments with the therapy neutron beam of the High-Flux Reactor (HFR).

  5. The accuracy of the Oculus Rift virtual reality head-mounted display during cervical spine mobility measurement.

    Science.gov (United States)

    Xu, Xu; Chen, Karen B; Lin, Jia-Hua; Radwin, Robert G

    2015-02-26

    An inertial sensor-embedded virtual reality (VR) head-mounted display, the Oculus Rift (the Rift), monitors head movement so the content displayed can be updated accordingly. While the Rift may have potential use in cervical spine biomechanics studies, its accuracy in terms of cervical spine mobility measurement has not yet been validated. In the current study, a VR environment was designed to guide participants to perform prescribed neck movements. The cervical spine kinematics was measured by both the Rift and a reference motion tracking system. Comparison of the kinematics data between the Rift and the tracking system indicated that the Rift can provide good estimates on full range of motion (from one side to the other side) during the performed task. Because of inertial sensor drifting, the unilateral range of motion (from one side to neutral posture) derived from the Rift is more erroneous. The root-mean-square errors over a 1-min task were within 10° for each rotation axis. The error analysis further indicated that the inertial sensor drifted approximately 6° at the beginning of a trial during the initialization. This needs to be addressed when using the Rift in order to more accurately measure cervical spine kinematics. It is suggested that the front cover of the Rift should be aligned against a vertical plane during its initialization.

  6. Design of hydraulic recuperation unit

    Directory of Open Access Journals (Sweden)

    Jandourek Pavel

    2016-01-01

    Full Text Available This article deals with design and measurement of hydraulic recuperation unit. Recuperation unit consist of radial turbine and axial pump, which are coupled on the same shaft. Speed of shaft with impellers are 6000 1/min. For economic reasons, is design of recuperation unit performed using commercially manufactured propellers.

  7. Determination of hydraulic conductivities of low permeability materials in the Sierra Ladrones Formation, Albuquerque basin

    Energy Technology Data Exchange (ETDEWEB)

    Planert, C.S.

    1995-06-01

    Low permeability materials in the Sierra Ladrones Formation were sampled and analyzed to determine their hydraulic conductivities using the falling head centrifugation method (fc) as described by Nimmo et al. (1991). The method is similar to the traditional falling head method, only it uses greatly increased centrifugal forces, allowing measurements to make in a relatively short amount of time. Using these measurements, variations in saturated hydraulic conductivities between different sediment types were analyzed using Analysis of Variance (ANOVA). Sampling resulted in useable data chiefly from the clay and silt facies of the formation. The range of conductivities determined are representative of brown and red clays, and silts which make up the overbank deposits of this region. Hydraulic conductivities for these overbank fines were found to range from approximately log K = {minus}9 m/s to log K = {minus}7 m/s. The upper measurement limit of the centrifuge apparatus was determined to be approximately 1.43 {times} 10{sup {minus}7} m/s and the lower limit was approximately 7.6 {times} 10{sup {minus}12} m/s.

  8. Numerical validation of linear accelerometer systems for the measurement of head kinematics.

    Science.gov (United States)

    Cappa, Paolo; Masia, Lorenzo; Patanè, Fabrizio

    2005-11-01

    The purpose of this study was to analytically exploit the capabilities of head-mounted systems instrumented with linear accelerometers (ACs) for field use in redundant configurations. We simulated different headsets equipped with uni-, bi- or triaxial sensors with a number of axes that lie in the range of 12-24; the ACs were located on a hemispherical surface by adopting a priori criterion while their orientation was randomized. In addition, for a comparative purpose the nine accelerometer scheme (one triaxial AC and three biaxial ACs addressed in the following as "3-2-2-2 configuration") was also analyzed in the present paper. We simulated and statistically assessed the performances of hemispherical headsets in the test case of a healthy subject walking freely at normal pace over level ground. The numerical results indicated that a well designed instrumented headset can retrieve the angular acceleration and (a0-g) component with rms errors of about 2% and 0.5%, respectively, and angular velocity with a drift error of about 20% in a 6 s trial. On the contrary, the pose of the headset cannot be evaluated because of the drift induced by the integration process. In general, we can state that headsets with uni-, bi- or triaxial ACs have comparable performances. The main implications of the above-mentioned observations are (a) neither expensive triaxial ACs nor assembling procedure based on the use of orthogonal mounting blocks are needed; (b) redundant arrays of low-cost uni- or biaxial ACs can effectively be used to reach adequate performances in biomechanical studies where head acceleration and velocity are investigated; (c) while estimates of angular acceleration with accelerometers are accurate, estimations of angular velocities, linear velocities and pose are not.

  9. Measurement of craniovertebral angle by the Modified Head Posture Spinal Curvature Instrument: A reliability and validity study.

    Science.gov (United States)

    Subbarayalu, Arun Vijay

    2016-01-01

    The Modified Head Posture Spinal Curvature Instrument (MHPSCI) is an extension of the Head Posture Spinal Curvature Instrument. Two specific modifications were made in the original design by adding a third arm projecting horizontally from the protractor to objectively fix the pivot exactly over the C7 vertebra and the addition of a spirit-level to properly align the instrument. In order to demonstrate reliability and validity, this study was conducted using patients with postural neck pain (N = 65) and healthy subjects (N = 20). All the subjects were working at a selected Information Technology Industry in India and had been recruited using a criterion-based sampling approach. The craniovertebral (CV) angle of each subject was evaluated by two raters consecutively. The measurements were taken by using both MHPSCI and the standard photographic method in a standardized sitting posture for the purpose of establishing criterion-validity of the instrument. The results of this study indicate a good inter-rater reliability (ICC = 0.76; CI = 0.65-0.84) as well as intra-rater reliability (ICC = 0.87; CI = 0.82-0.91) between three successive CV angle measurements (with 2 minutes interval between each measurement) through MHPSCI. While keeping the digital photographic measurement as a standard, this study established that the MHPSCI is a valid tool for measuring the CV angle as shown by non-significant difference (p > 0.01) and high correlation between the two methods (r = 0.79-0.84). This study demonstrates that the MHPSCI is a reliable and valid instrument for measuring CV angle in subjects with or without postural neck pain.

  10. Flow measurement in a 170-MW hydraulic turbine using the Gibson method; Medicion del flujo de una turbina hidraulica de 170 MW utilizando el metodo Gibson

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza, Gustavo [Universidad Autonoma del Estado de Morelos (Mexico); Adamkowski, Adam [The Szewalski Institute of Fluid-Flow Machinery (Poland); Kubiak, Janusz; Sierra, Fernando [Universidad Autonoma del Estado de Morelos (Mexico); Janicki, Waldemar [The Szewalski Institute of Fluid-Flow Machinery (Poland); Fernandez, J. Manuel [Comision Federal de Electricidad (Mexico)

    2007-07-15

    This paper describes the methodology applied for measuring water flow through a 170-MW hydraulic turbine. The flow rate was measured using the pressure-time method, also known as the Gibson method. This method uses the well-known water hammer phenomenon in pipelines; in turbine penstocks, for instance. The version of this method used here is based on measuring, during total stop of the water stream, the time-history of pressure change in one section of the turbine penstock and relate it to the pressure in the upper reservoir to which the penstock is connected. The volumetric flow rate is determined from the relevant integration of the measured temporary pressure rise. Flow measurement was possible this way because the influence of the penstock inlet was negligible as far as an error of the measurement is concerned. The length of the penstock was 300 m. Previous experience and a standard IEC-41-1991 were the criteria adopted and applied. A fast and efficient acquisition system, including a 16 bit card, was used. The flow rate was calculated using a computer program developed and tested on several cases. The results obtained with the Gibson method were used for calibration of the on-line flow measuring system based on the Winter-Kennedy method as one of the index methods. This method is very often used for continuous monitoring of the flow rate through hydraulic turbines, when the calibration has been done on site by using the results of measurements obtained by the absolute method. Having measured the flow rate and output power, the efficiency was calculated for any operating conditions. A curve showing the best operating conditions based on the highest efficiency is presented and discussed. The details of the instrumentation, its installation, and the results obtained are discussed in the paper. [Spanish] Este articulo describe la metodologia aplicada para la medicion del flujo en una turbina hidraulica de 170 MW. El flujo se midio utilizando el metodo de presion

  11. Measurement of Hybrid III Head Impact Kinematics Using an Accelerometer and Gyroscope System in Ice Hockey Helmets.

    Science.gov (United States)

    Allison, Mari A; Kang, Yun Seok; Maltese, Matthew R; Bolte, John H; Arbogast, Kristy B

    2015-08-01

    Helmet-based instrumentation is used to study the biomechanics of concussion. The most extensively used systems estimate rotational acceleration from linear acceleration, but new instrumentation measures rotational velocity using gyroscopes, potentially reducing error. This study compared kinematics from an accelerometer and gyroscope-containing system to reference measures. A Hybrid III (HIII) adult male anthropometric test device head and neck was fit with two helmet brands, each instrumented with gForce Tracker (GFT) sensor systems in four locations. Helmets were impacted at various speeds and directions. Regression relationships between GFT-measured and reference peak kinematics were quantified, and influence of impact direction, sensor location, and helmet brand was evaluated. The relationship between the sensor output and the reference acceleration/velocity experienced by the head was strong. Coefficients of determination for data stratified by individual impact directions ranged from 0.77 to 0.99 for peak linear acceleration and from 0.78 to 1.0 for peak rotational velocity. For the data from all impact directions combined, coefficients of determination ranged from 0.60 to 0.80 for peak resultant linear acceleration and 0.83 to 0.91 for peak resultant rotational velocity. As expected, raw peak resultant linear acceleration measures exhibited large percent differences from reference measures. Adjustment using regressions resulted in average absolute errors of 10-15% if regression adjustments were done by impact direction or 25-40% if regressions incorporating data from all impact directions were used. Average absolute percent differences in raw peak resultant rotational velocity were much lower, around 10-15%. It is important to define system accuracy for a particular helmet brand, sensor location, and impact direction in order to interpret real-world data.

  12. 孤独症患儿头围测量分析%Head circumference measurements in children with autism

    Institute of Scientific and Technical Information of China (English)

    谭迎花; 郗春艳; 汪永娟; 王丽波; 韩晶晶

    2011-01-01

    Objective To assess the head circumference in children with autism. Methods One hundred and fifty-six children with autism (74 children ≤ 3 years and 82 children > 3 years, respectively) and 141 well-matched healthy controls (58 children ≤3 years and 83 children > 3 years, respectively) were investigated by measuring the head circumference. Results The autistic children demonstrated significantly higher head circumference than the control children in the ≤3 years group (P 3岁82例.同时选择健康儿童141名作为正常对照组,其中≤3岁58名,>3岁83名.分别测量两组头围并进行组间比较.结果 孤独症组≤3岁患儿头围平均值与大头所占比例均大于正常对照组,两组差异有统计学意义(P 0.05).在除外大头患儿后,两组头围平均值比较差异无统计学意义(P > 0.05).结论 孤独症患儿生后早期头围偏大,并且常伴大头,头围异常也是患儿重要的临床特征之一.了解孤独症头围发育可为孤独症的发病机制提供参考依据.

  13. SU-F-SPS-03: Direct Measurement of Organ Doses Resulting From Head and Cervical Spine Trauma CT Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, C; Lipnharski, I; Quails, N; Correa, N; Rill, L; Arreola, M [University of Florida, Gainesville, FL (United States)

    2016-06-15

    Purpose: This retrospective study analyzes the exposure history of emergency department (ED) patients undergoing head and cervical spine trauma computed tomography (CT) studies. This study investigated dose levels received by trauma patients and addressed any potential concerns regarding radiation dose issues. Methods: Under proper IRB approval, a cohort of 300 trauma cases of head and cervical spine trauma CT scans received in the ED was studied. The radiological image viewing software of the hospital was used to view patient images and image data. The following parameters were extracted: the imaging history of patients, the reported dose metrics from the scanner including the volumetric CT Dose Index (CTDIvol) and Dose Length Product (DLP). A postmortem subject was scanned using the same scan techniques utilized in a standard clinical head and cervical spine trauma CT protocol with 120 kVp and 280 mAs. The CTDIvol was recorded for the subject and the organ doses were measured using optically stimulated luminescent (OSL) dosimeters. Typical organ doses to the brain, thyroid, lens, salivary glands, and skin, based on the cadaver studies, were then calculated and reported for the cohort. Results: The CTDIvol reported by the CT scanner was 25.5 mGy for the postmortem subject. The average CTDIvol from the patient cohort was 34.1 mGy. From these metrics, typical average organ doses in mGy were found to be: Brain (44.57), Thyroid (33.40), Lens (82.45), Salivary Glands (61.29), Skin (47.50). The imaging history of the cohort showed that on average trauma patients received 26.1 scans over a lifetime. Conclusion: The average number of scans received on average by trauma ED patients shows that radiation doses in trauma patients may be a concern. Available dose tracking software would be helpful to track doses in trauma ED patients, highlighting the importance of minimizing unnecessary scans and keeping doses ALARA.

  14. Permeability Enhancement in Enhanced Geothermal System as a result of Hydraulic Fracturing and Jacking

    Science.gov (United States)

    Jalali, Mohammadreza; Klepikova, Maria; Fisch, Hansruedi; Amann, Florian; Loew, Simon

    2016-04-01

    -coring tests, these data were used to conclude on the local stress orientation and stress magnitudes. The hydraulic response of the rock mass under hydro-mechanical perturbations was investigated by conducting various hydraulic packer tests (e.g. pulse, constant rate and constant head) in multiple hydraulically isolated borehole sections before and after the stress measurements. Hydraulic testing of borehole sections which were previously fracked (during HF tests) didn't show a distinct increase in permeability. For the tested borehole sections without natural fractures, this can be explained by the fact that hydraulic fracturing was dominated by fracture normal opening (mode I). In this case, the implemented pressure range (less than 2 MPa) during the hydraulic packer tests was not sufficient to re-open the tensile fractures and permeability would remain unchanged. Conversely, in borehole sections with pre-existing ductile and/or brittle fractures and where HTPF-tests were conducted, the permeability increased by two orders of magnitude, from 10-11 m2/s to˜10-9 m2/s (results of hydraulic tests pre and post HTPF). These findings could be explained by permanent enhancement of permeability as a result of shear dilation of existing structures. Considering the efficiency of the hydraulic stimulation process observed at low differential injection pressures, even more significant permeability enhancement is expected during the upcoming stimulation experiments.

  15. Improved Sensing Pulses for Increased Human Head Depth Measurement Sensitivity With Electrical Impedance Spectroscopy

    Science.gov (United States)

    Lev, Michael H.

    2017-01-01

    This paper describes an improved electrical impedance spectroscopy (EIS) stimulus paradigm, based on dual-energy pulses using the stochastic Gabor function (SGF) that may more sensitively assess deep brain tissue impedance than current single-pulse paradigms. The SGF is a uniformly distributed noise, modulated by a Gaussian envelope, with a wide-frequency spectrum representation regardless of the stimuli energy, and is least compact in the sample frequency phase plane. Numerical results obtained using a realistic human head model confirm that two sequential SGF pulses at different energies can improve EIS depth sensitivity when used in a dual-energy subtraction scheme. Specifically, although the two SGF pulses exhibit different tissue current distributions, they maintain the broadband sensing pulse characteristics needed to generate all the frequencies of interest. Moreover, finite-difference time domain simulations show that this dual-energy excitation scheme is capable of reducing the amplitude of weighted current densities surface directly underneath the electrodes by approximately 3 million times versus single stimulation pulses, while maintaining an acceptable tissue conductivity distribution at depth. This increased sensitivity for the detection of small, deep impedance changes might be of value in potential future EIS applications, such as the portable, point-of-care detection of deep brain hemorrhage or infarction. PMID:24043365

  16. Laser Doppler measurement of relative blood velocity in the human optic nerve head.

    Science.gov (United States)

    Riva, C E; Grunwald, J E; Sinclair, S H

    1982-02-01

    The Doppler shift frequency spectrum (DSFS) of laser light scattered from red blood cells (RBCs) moving in the microcirculation of the optic nerve head has been recorded in normal volunteers by means of a fundus camera laser Doppler velocimeter. The width of the DSFS, which varies in proportion to the speed of the RBCs, has been characterized by a parameter alpha. With the use of a model for the scattering of light by tissue and RBCs and for the RBC velocity distribution, values of alpha recorded at normal intraocular pressure (IOP) suggest that the RBCs that contribute to the Doppler signal are flowing in capillaries. The parameter alpha was found to vary markedly with the IOP and with the phase of the ocular pressure pulse at elevated IOP. The return of the speed of RBCs toward normal, which is observed after a step increase of IOP above normal and after a step decrease below normal, has been attributed to an autoregulatory response of the optic nerve circulation.

  17. VHF SoOp (Signal of Opportunity) Technology Demonstration for Soil Moisture Measurement Using Microwave Hydraulic Boom Truck Platform

    Science.gov (United States)

    Joseph, Alicia; Deshpande, Manohar; O'Neill, Peggy; Miles, Lynn

    2017-04-01

    A goal of this research is to test deployable VHF antennas for 6U Cubesat platforms to enable validation of root zone soil moisture (RZSM) estimation algorithms for signal of opportunity (SoOp) remote sensing over the 240-270 MHz frequency band. The proposed work provides a strong foundation for establishing a technology development path for maturing a global direct surface soil moisture (SM) and RZSM measurement system over a variety of land covers. Knowledge of RZSM up to a depth of 1 meter and surface SM up to a depth of 0.05 meter on a global scale, at a spatial resolution of 1-10 km through moderate-to-heavy vegetation, is critical to understanding global water resources and the vertical moisture gradient in the Earth's surface layer which controls moisture interactions between the soil, vegetation, and atmosphere. Current observations of surface SM from space by L-band radiometers (1.4 GHz) and radars (1.26 GHz) are limited to measurements of surface SM up to a depth of 0.05 meter through moderate amounts of vegetation. This limitation is mainly due to the inability of L-band signals to penetrate through dense vegetation and deep into the soil column. Satellite observations of the surface moisture conditions are coupled to sophisticated models which extrapolate the surface SM into the root zone, thus providing an indirect estimate rather than a direct measurement of RZSM. To overcome this limitation, low-frequency airborne radars operating at 435 MHz and 118 MHz have been investigated, since these lower frequencies should penetrate denser vegetation and respond to conditions deeper in the soil. This presentation describes a new and less expensive technique for SM as well as RZSM direct measurement using Signal of Opportunity transmitters. Being less expensive and needing only passive simple RF receiver, the SoOp concept has the potential for being used for space borne applications, thus providing global SM and RZSM measurements. This study will describe

  18. VHF SoOp (Signal of Opportunity) Technology Demonstration for Soil Moisture Measurement Using Microwave Hydraulic Boom Truck Platform

    Science.gov (United States)

    Joseph, A. T.; Deshpande, M.; O'Neill, P. E.; Miles, L.

    2017-01-01

    A goal of this research is to test deployable VHF antennas for 6U Cubesat platforms to enable validation of root zone soil moisture (RZSM) estimation algorithms for signal of opportunity (SoOp) remote sensing over the 240-270 MHz frequency band. The proposed work provides a strong foundation for establishing a technology development path for maturing a global direct surface soil moisture (SM) and RZSM measurement system over a variety of land covers. Knowledge of RZSM up to a depth of 1 meter and surface SM up to a depth of 0.05 meter on a global scale, at a spatial resolution of 1-10 km through moderate-to-heavy vegetation, is critical to understanding global water resources and the vertical moisture gradient in the Earths surface layer which controls moisture interactions between the soil, vegetation, and atmosphere. Current observations of surface SM from space by L-band radiometers (1.4 GHz) and radars (1.26 GHz) are limited to measurements of surface SM up to a depth of 0.05 meter through moderate amounts of vegetation. This limitation is mainly due to the inability of L-band signals to penetrate through dense vegetation and deep into the soil column. Satellite observations of the surface moisture conditions are coupled to sophisticated models which extrapolate the surface SM into the root zone, thus providing an indirect estimate rather than a direct measurement of RZSM. To overcome this limitation, low-frequency airborne radars operating at 435 MHz and 118 MHz have been investigated, since these lower frequencies should penetrate denser vegetation and respond to conditions deeper in the soil.

  19. Effect of Adsorbed Protein on the Hydraulic Permeability, Membrane and Streaming Potential Values Measured across a Microporous Membrane

    DEFF Research Database (Denmark)

    Benavente, Juana; Jonsson, Gunnar Eigil

    1998-01-01

    different experimental conditions may be attributed to different mechanisms for the adsorption of proteins in the membrane: (i) a protein deposition on the membrane pores; () an adsorbed layer of protein on the membrane surface. In this latter case, the whole membrane system can be considered......The effect of the adsorption of a protein, bovine serum albumin (BSA), on the membrane potential, flux reduction and streaming potential measured across a microporous polysulphone membrane with different NaCl solutions and pH values is studied. From electrokinetic phenomena, information about...

  20. Design of a laboratory hydraulic device for testing of hydraulic pumps

    Directory of Open Access Journals (Sweden)

    Pavel Máchal

    2013-01-01

    Full Text Available The present contribution deals with solves problem of research of testing device to monitor of hydrostatic pumps durability about dynamic loading under laboratory conditions. When carrying out the design of testing device are based on load characteristics of tractor hydraulic circuit, the individual characteristics of hydraulic components and performed calculations. Load characteristics on the tractors CASE IH Magnum 310, JOHN DEERE 8100, ZETOR FORTERRA 114 41 and Fendt 926 Vario were measured. Design of a hydraulic laboratory device is based on the need for testing new types of hydraulic pumps or various types of hydraulic fluids. When creating of hydraulic device we focused on testing hydraulic pumps used in agricultural and forestry tractors. Proportional pressure control valve is an active member of the hydraulic device, which provides change of a continuous control signal into relative pressure of operating fluid. The advantage of a designed hydraulic system is possibility of simulation of dynamic operating loading, which is obtained by measurement under real conditions, and thereby creates laboratory conditions as close to real conditions as possible. The laboratory device is constructed at the Department of Transport and Handling, Faculty of Engineering, Slovak University of Agriculture in Nitra.

  1. Characteristics analysis for different water heads on the efficiency hill chart of Francis turbine

    Science.gov (United States)

    Wang, Z. N.; Guo, P. C.; Luo, X. Q.; Wang, Y. L.; Sun, S. H.

    2016-05-01

    Based on the test results of Francis turbine, the causes and inevitability of various hydraulic phenomena in the model combined characteristic curve for typical water heads were analyzed in this paper. the difference of the model combined characteristic curve from the low water head to the high water head is compared, and the characteristics and commonness of the model combined characteristic curve about different water head are summarized. Further, hydraulic performance and geometric features of Francis turbine are revealed by particularly analyzing model combined characteristic curves, and to provide powerful theoretical basis and definite modification direction for the hydraulic design of hydraulic turbine.

  2. Enhanced patient reported outcome measurement suitable for head and neck cancer follow-up clinics.

    Science.gov (United States)

    Ghazali, Naseem; Lowe, Derek; Rogers, Simon N

    2012-06-13

    The 'Worse-Stable-Better' (W-S-B) question was introduced to capture patient-perceived change in University of Washington Quality of Life (UW-QOL) domains. 202 head and neck cancer patients in remission prospectively completed UW-QOL and Patients Concerns Inventory (PCI). For each UW-QOL domain, patients indicated whether over the last month things had worsened (W), remained stable (S) or were better (B). 202 patients at 448 attendances selected 1752 PCI items they wanted to discuss in consultation, and 58% (1024/1752) of these were not covered by the UW-QOL. UW-QOL algorithms highlighted another 440 significant problems that the patient did not want to discuss (i.e. the corresponding items on the PCI were not selected).After making allowance for UW-QOL algorithms to identify 'significant problems' and PCI selection of corresponding issues for discussion there remained clear residual and notable variation in W-S-B responses, in particular to identify patients with significant problems that were getting worse, and patients without significant problems that wanted to discuss issues that were getting worse. Changes in mean UW-QOL scores were notably lower for those getting worse on the W-S-B question, typically by 10 or more units a magnitude that suggests clinically important changes in score. The W-S-B question adds little questionnaire burden and could help to better identify patients who might benefit from intervention. The results of this study suggest that the UW-QOL with the W-S-B modification should be used together with the PCI to allow optimal identification of issues for patient-clinician discussion during routine outpatient clinics.

  3. Extracting Speed, Heading and Turn-Rate Measurements from Extended Objects using the EM Algorithm

    Science.gov (United States)

    2015-03-11

    the measurement noise is isotropic. If we define d as di = [ xd (i) yd(i) ] = zi − x (44) and f (di) as the measured range and angle of the measure...ment relative to the state x f (di) = [ √ x2d(i) + y 2 d(i) tan−1 ( yd(i) xd (i) ) ] (45) The distribution of di, given the measurement assignment is...linearization p (f (di) |Y) ≈ N ([ s √ x2t (j) + y 2 t (j) tan−1 ( yt(j) xt(j) ) + ψ ] ,Σ ) (47) where L = [ ∂f1 ∂ xd (i) ∂f1 ∂yd(i) ∂f2 ∂ xd (i) ∂f2 ∂yd(i

  4. Effects of Olympic-style taekwondo kicks on an instrumented head-form and resultant injury measures.

    Science.gov (United States)

    Fife, Gabriel P; O'Sullivan, David M; Pieter, Willy; Cook, David P; Kaminski, Thomas W

    2013-12-01

    The objective of this study was to assess the effect of taekwondo kicks and peak foot velocity (FVEL) on resultant head linear acceleration (RLA), head injury criterion (HIC15) and head velocity (HVEL). Each subject (n=12) randomly performed five repetitions of the turning kick (TK), clench axe kick (CA), front leg axe kick, jump back kick (JB) and jump spinning hook kick (JH) at the average standing head height for competitors in their weight division. A Hybrid II Crash Test Dummy head was fitted with a protective taekwondo helmet and instrumented with a triaxial accelerometer and fixed to a height-adjustable frame. Resultant head linear acceleration, HVEL, FVEL data were captured and processed using Qualysis Track Manager. The TK (130.11 ± 51.67 g) produced a higher RLA than the CA (54.95 ± 20.08 g, ptaekwondo. Future studies should aim to understand rotational accelerations of the head.

  5. Detection of QTL for exudation rate at ripening stage in rice and its contribution to hydraulic conductance.

    Science.gov (United States)

    Yamamoto, Toshio; Suzuki, Tadafumi; Suzuki, Kenji; Adachi, Shunsuke; Sun, Jian; Yano, Masahiro; Ookawa, Taiichiro; Hirasawa, Tadashi

    2016-01-01

    Dry matter production of crops is determined by how much light they intercept and how efficiently they use it for carbon fixation; i.e., photosynthesis. The high-yielding rice cultivar, Akenohoshi, maintains a high photosynthetic rate in the middle of the day owing to its high hydraulic conductance in comparison with the elite commercial rice cultivar, Koshihikari. We developed 94 recombinant inbred lines derived from Akenohoshi and Koshihikari and measured their exudation rate to calculate hydraulic conductance to osmotic water transport in a paddy field. A quantitative trait locus (QTL) for exudation rate was detected on the long arm of chromosome 2 at the heading and ripening stages. We developed chromosome segment substitution lines which carried Akenohoshi segments in the Koshihikari genetic background, and measured hydraulic conductance to both osmotic and passive water transport. The QTL was confirmed to be located within a region of about 4.2Mbp on the distal end of long arm of chromosome 2. The Akenohoshi allele increased root surface area and hydraulic conductance, but didn't increase hydraulic conductivity of a plant.

  6. Measurement of six degrees of freedom head kinematics in impact conditions employing six accelerometers and three angular rate sensors (6aω configuration).

    Science.gov (United States)

    Kang, Yun-Seok; Moorhouse, Kevin; Bolte, John H

    2011-11-01

    The ability to measure six degrees of freedom (6 DOF) head kinematics in motor vehicle crash conditions is important for assessing head-neck loads as well as brain injuries. A method for obtaining accurate 6 DOF head kinematics in short duration impact conditions is proposed and validated in this study. The proposed methodology utilizes six accelerometers and three angular rate sensors (6aω configuration) such that an algebraic equation is used to determine angular acceleration with respect to the body-fixed coordinate system, and angular velocity is measured directly rather than numerically integrating the angular acceleration. Head impact tests to validate the method were conducted using the internal nine accelerometer head of the Hybrid III dummy and the proposed 6aω scheme in both low (2.3 m/s) and high (4.0 m/s) speed impact conditions. The 6aω method was compared with a nine accelerometer array sensor package (NAP) as well as a configuration of three accelerometers and three angular rate sensors (3aω), both of which have been commonly used to measure 6 DOF kinematics of the head for assessment of brain and neck injuries. The ability of each of the three methods (6aω, 3aω, and NAP) to accurately measure 6 DOF head kinematics was quantified by calculating the normalized root mean squared deviation (NRMSD), which provides an average percent error over time. Results from the head impact tests indicate that the proposed 6aω scheme is capable of producing angular accelerations and linear accelerations transformed to a remote location that are comparable to that determined from the NAP scheme in both low and high speed impact conditions. The 3aω scheme was found to be unable to provide accurate angular accelerations or linear accelerations transformed to a remote location in the high speed head impact condition due to the required numerical differentiation. Both the 6aω and 3aω schemes were capable of measuring accurate angular displacement while the

  7. A wireless swing angle measurement scheme using attitude heading reference system sensing units based on microelectromechanical devices.

    Science.gov (United States)

    Gao, Bingtuan; Zhu, Zhenyu; Zhao, Jianguo; Huang, Boran

    2014-11-27

    Feasible real-time swing angle measurement is significant to improve the efficiency and safety of industrial crane systems. This paper presents a wireless microelectromechanical system (MEMS)-based swing angle measurement system. The system consists of two attitude heading reference system (AHRS) sensing units with a wireless communication function, which are mounted on the hook (or payload) and the jib (or base) of the crane, respectively. With a combination of a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer, the standard extended Kalman filter (EKF) is used to estimate the desired orientation of the payload and the base. Wireless ZigBee communication is employed to transmit the orientation of the payload to the sensing unit mounted on the base, which measures the orientation of the base. Because several physical parameters from the payload to the base can be acquired from the original crane control system, the swing angles of the payload can be calculated based on the two measured orientation parameters together with the known physical parameters. Experiments were performed to show the feasibility and effectiveness of the proposed swing angle measurement system.

  8. A Wireless Swing Angle Measurement Scheme Using Attitude Heading Reference System Sensing Units Based on Microelectromechanical Devices

    Directory of Open Access Journals (Sweden)

    Bingtuan Gao

    2014-11-01

    Full Text Available Feasible real-time swing angle measurement is significant to improve the efficiency and safety of industrial crane systems. This paper presents a wireless microelectromechanical system (MEMS-based swing angle measurement system. The system consists of two attitude heading reference system (AHRS sensing units with a wireless communication function, which are mounted on the hook (or payload and the jib (or base of the crane, respectively. With a combination of a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer, the standard extended Kalman filter (EKF is used to estimate the desired orientation of the payload and the base. Wireless ZigBee communication is employed to transmit the orientation of the payload to the sensing unit mounted on the base, which measures the orientation of the base. Because several physical parameters from the payload to the base can be acquired from the original crane control system, the swing angles of the payload can be calculated based on the two measured orientation parameters together with the known physical parameters. Experiments were performed to show the feasibility and effectiveness of the proposed swing angle measurement system.

  9. Intersubjectivity as a Measure of Social Competence among Children Attending Head Start: Assessing the Measure's Validity and Relation to Context

    Science.gov (United States)

    Garte, Rebecca R.

    2015-01-01

    The present paper reported on a new method and procedure for assessing preschooler's social competence. This method utilized an observational measure of intersubjectivity to assess the social competence that develops in real time during interaction between two or more children. The measure of intersubjectivity reflected a conceptualization of the…

  10. Radiocarbon measurements of stromatolite heads and crusts at the Salgada Lagoon, Rio de Janeiro State, Brazil

    Science.gov (United States)

    Coimbra, Melayne M.; Silva, Cleverson G.; Barbosa, Cátia F.; Mueller, Ken A.

    2000-10-01

    In this work, we prepared and measured some stromatolite carbonate samples, from Salgada Lagoon, Rio de Janeiro, Brazil. Stromatolites are bio-sedimentary, laminated, carbonate structures produced by sedimentary, chemical and biological processes related to the development and growth of microbial benthic communities, mainly dominated by blue algae and cyanobacteria. These structures are present in the geological record in rocks older than 3.0 billion years and have been used to study the origin of primitive life and variations in past environmental conditions. Detailed AMS measurements were performed at PRIME Lab (Purdue Rare Isotope Measurement Laboratory, Purdue University, IN, USA).

  11. Effects of biochars on hydraulic properties of clayey soil

    Science.gov (United States)

    Zhen, Jingbo; Palladino, Mario; Lazarovitch, Naftali; Bonanomi, Giuliano; Battista Chirico, Giovanni

    2017-04-01

    Biochar has gained popularity as an amendment to improve soil hydraulic properties. Since biochar properties depend on feedstocks and pyrolysis temperatures used for its production, proper selection of biochar type as soil amendment is of great importance for soil hydraulic properties improvement. This study investigated the effects of eight types of biochar on physical and hydraulic properties of clayey soil. Biochars were derived from four different feedstocks (Alfalfa hay, municipal organic waste, corn residues and wood chip) pyrolyzed at two different temperatures (300 and 550 °C). Clayey soil samples were taken from Leone farm (40° 26' 15.31" N, 14° 59' 45.54" E), Italy, and were oven-dried at 105 °C to determine dry bulk density. Biochars were mixed with the clayey soil at 5% by mass. Bulk densities of the mixtures were also determined. Saturated hydraulic conductivities (Ks) of the original clayey soil and corresponding mixtures were measured by means of falling-head method. Soil water retention measurements were conducted for clayey soil and mixtures using suction table apparatus and Richards' plate with the pressure head (h) up to 12000 cm. van Genuchten retention function was selected to evaluate the retention characteristics of clayey soil and mixtures. Available water content (AWC) was calculated by field capacity (h = - 500 cm) minus wilting pointing (h = -12000 cm). The results showed that biochar addition decreased the bulk density of clayey soil. The Ks of clayey soil increased due to the incorporation of biochars except for waste and corn biochars pyrolyzed at 550 °C. AWC of soils mixed with corn biochar pyrolyzed at 300 °C and wood biochar pyrolyzed at 550 °C, increased by 31% and 7%, respectively. Further analysis will be conducted in combination of biochar properties such as specific surface area and total pore volume. Better understanding of biochar impact on clayey soil will be helpful in biochar selection for soil amendment and

  12. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  13. Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

    Science.gov (United States)

    Fu, Congsheng; Wang, Guiling; Goulden, Michael L.; Scott, Russell L.; Bible, Kenneth; Cardon, Zoe G.

    2016-05-01

    Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site comparisons for contrasting climate regimes and multiple vegetation types via the integration of measurement and modeling. Here, we incorporated the HR scheme of Ryel et al. (2002) into the NCAR Community Land Model Version 4.5 (CLM4.5), and examined the ability of the resulting hybrid model to capture the magnitude of HR flux and/or soil moisture dynamics from which HR can be directly inferred, to assess the impact of HR on land surface water and energy budgets, and to explore how the impact may depend on climate regimes and vegetation conditions. Eight AmeriFlux sites with contrasting climate regimes and multiple vegetation types were studied, including the Wind River Crane site in Washington State, the Santa Rita Mesquite savanna site in southern Arizona, and six sites along the Southern California Climate Gradient. HR flux, evapotranspiration (ET), and soil moisture were properly simulated in the present study, even in the face of various uncertainties. Our cross-ecosystem comparison showed that the timing, magnitude, and direction (upward or downward) of HR vary across ecosystems, and incorporation of HR into CLM4.5 improved the model-measurement matches of evapotranspiration, Bowen ratio, and soil moisture particularly during dry seasons. Our results also reveal that HR has important hydrological impact in ecosystems that have a pronounced dry season but are not overall so dry that sparse vegetation and very low soil moisture limit HR.

  14. Combining multi-objective optimization and bayesian model averaging to calibrate forecast ensembles of soil hydraulic models

    Energy Technology Data Exchange (ETDEWEB)

    Vrugt, Jasper A [Los Alamos National Laboratory; Wohling, Thomas [NON LANL

    2008-01-01

    Most studies in vadose zone hydrology use a single conceptual model for predictive inference and analysis. Focusing on the outcome of a single model is prone to statistical bias and underestimation of uncertainty. In this study, we combine multi-objective optimization and Bayesian Model Averaging (BMA) to generate forecast ensembles of soil hydraulic models. To illustrate our method, we use observed tensiometric pressure head data at three different depths in a layered vadose zone of volcanic origin in New Zealand. A set of seven different soil hydraulic models is calibrated using a multi-objective formulation with three different objective functions that each measure the mismatch between observed and predicted soil water pressure head at one specific depth. The Pareto solution space corresponding to these three objectives is estimated with AMALGAM, and used to generate four different model ensembles. These ensembles are post-processed with BMA and used for predictive analysis and uncertainty estimation. Our most important conclusions for the vadose zone under consideration are: (1) the mean BMA forecast exhibits similar predictive capabilities as the best individual performing soil hydraulic model, (2) the size of the BMA uncertainty ranges increase with increasing depth and dryness in the soil profile, (3) the best performing ensemble corresponds to the compromise (or balanced) solution of the three-objective Pareto surface, and (4) the combined multi-objective optimization and BMA framework proposed in this paper is very useful to generate forecast ensembles of soil hydraulic models.

  15. Diffuse optical measurements of head and neck tumor hemodynamics for early prediction of radiation therapy (Conference Presentation)

    Science.gov (United States)

    Dong, Lixin; Kudrimoti, Mahesh; Irwin, Daniel; Chen, Li; Shang, Yu; Li, Xingzhe; Stevens, Scott D.; Shelton, Brent J.; Yu, Guoqiang

    2016-03-01

    Radiation therapy is a principal modality for head and neck cancers and its efficacy depends on tumor hemodynamics. Our laboratory developed a hybrid diffuse optical instrument allowing for simultaneous measurements of tumor blood flow and oxygenation. In this study, the clinically involved cervical lymph node was monitored by the hybrid instrument once a week over the treatment period of seven weeks. Based on treatment outcomes within one year, patients were classified into a complete response group (CR) and an incomplete response group (IR) with remote metastasis and/or local recurrence. A linear mixed models was used to compare tumor hemodynamic responses to the treatment between the two groups. Interestingly, we found that human papilloma virus (HPV-16) status largely affected tumor hemodynamic responses. For HPV-16 negative tumors, significant differences in blood flow index (BFI, p = 0.007) and reduced scattering coefficient (μs', p = 0.0005) were observed between the two groups; IR tumors exhibited higher μs' values and a continuous increase in BFI over the treatment period. For HPV-16 positive tumors, oxygenated hemoglobin concentration ([HbO2]) and blood oxygen saturation (StO2) were significant different (p = 0.003 and 0.01, respectively); IR group showed lower [HbO2] and StO2. Our results imply HPV-16 negative tumors with higher density of vasculature (μs') and higher blood flow show poor responses to radiotherapy and HPV-16 positive tumors with lower tissue oxygenation level (lower StO2 and [HbO2]) exhibit poor treatment outcomes. Our diffuse optical measurements show the great potential for early prediction of radiotherapy in head and neck cancers.

  16. Hydraulic test for evaluation of hydrophone VSP

    Energy Technology Data Exchange (ETDEWEB)

    Yabuuchi, Satoshi; Koide, Kaoru [Power Reactor and Nuclear Fuel Development Corp., Toki, Gifu (Japan). Tono Geoscience Center

    1997-12-01

    This hydraulic test was carried out at the test site of Tono Geoscience Center, Mizunami-shi, Gifu Pref. in order to evaluate the reliability of the hydraulic conductivity estimated from hydrophone VSP experiment. From March to April 1997, we carried out measurements of pore-water pressure at five depths and permeability tests at seven depths down to G.L.-300m, within a borehole drilled in granitic rock. We compared the results of hydraulic test with hydrophone VSP experiment on condition that a single open fracture existed, and we obtained two notable results. First, for the granitic rock at which a single open fracture was found by BTV and also detected by hydrophone VSP experiment, the hydraulic conductivity was 1.54 x 10{sup -7} cm/sec, while for the same granitic rock at which another single open fracture was found by BTV but not detected by hydrophone VSP experiment, the hydraulic conductivity was less than 6 x 10{sup -10} cm/sec. Second, we converted the hydraulic conductivity of 1.54 x 10{sup -7} cm/sec which was obtained in a hydraulic test section of length 2.5 m into an equivalent value for a single open fracture of width 1 mm. The converted value (3.8 x 10{sup -4} cm/sec) was similar to the hydraulic conductivity estimated from hydrophone VSP experiment. In conclusion, the hydraulic test result shows that hydrophone VSP is useful to estimate an approximate hydraulic conductivity of a single open fracture. (author)

  17. Integrating hydraulic equivalent sections into a hydraulic geometry study

    Science.gov (United States)

    Jia, Yanhong; Yi, Yujun; Li, Zhiwei; Wang, Zhaoyin; Zheng, Xiangmin

    2017-09-01

    Hydraulic geometry (HG) is an important geomorphic concept that has played an indispensable role in hydrological analyses, physical studies of streams, ecosystem and aquatic habitat studies, and sedimentology research. More than 60 years after Leopold and Maddock (1953) first introduced the concept of HG, researchers have still not uncovered the physical principles underlying HG behavior. One impediment is the complexity of the natural river cross section. The current study presents a new way to simplify the cross section, namely, the hydraulic equivalent section, which is generalized from the cross section in the ;gradually varied flow of an alluvial river; (GVFAR) and features hydrodynamic properties and bed-building laws similar to those of the GVFAR. Energy balance was used to derive the stage Z-discharge Q relationship in the GVFAR. The GVFAR in the Songhua River and the Yangtze River were selected as examples. The data, including measured discharge, river width, water stage, water depth, wet area, and cross section, were collected from the hydrological yearbooks of typical hydrological stations on the Songhua River and the Yangtze River from 1955 to 1987. The relationships between stage Z-discharge Q and cross-sectional area A-stage Z at various stations were analyzed, and ;at-a-station hydraulic geometry; (AHG) relationships were obtained in power-law forms. Based on derived results and observational data analysis, the Z-Q and Z-A relationships of AHG were similar to rectangular weir flows, thus the cross section of the GVFAR was generalized as a compound rectangular, hydraulic equivalent cross section. As to bed-building characteristics, the bankfull discharge method and the stage-discharge-relation method were used to calculate the dominant variables of the alluvial river. This hydraulic equivalent section has the same Z-Q relation, Z-A relation, dominant discharge, dominant river width, and dominant water depth as the cross section in the GVFAR. With the

  18. Hydraulic Conductivity Anisotropy of Heterogeneous Unsaturated Soils

    Science.gov (United States)

    Sun, Dongmin; Zhu, Jianting

    2010-05-01

    The effects of saturation degree (or capillary pressure) on hydraulic conductivity anisotropy in unsaturated soils have not been fully understood. This study developed an approach based on a conceptualization of combining the neural network based pedo-transfer function (PTF) results with the thin layer concept to explore the capillary pressure-dependent anisotropy in relation to soil texture and soil bulk density. The main objective is to examine how anisotropy characteristics are related to the relationships between hydraulic parameters and the basic soil attributes such as texture and bulk density. The hydraulic parameters are correlated with the texture and bulk density based on the pedo-transfer function (PTF) results. It is demonstrated that non-monotonic behavior of the unsaturated soil anisotropy in relation to the capillary pressure is only observed when the saturated hydraulic conductivity and the shape parameter are both related to the mean particle diameter. When only one hydraulic parameter is related to the grain diameter or when both are not related to the same attribute simultaneously, the unsaturated soil anisotropy increases monotonically with the increasing capillary pressure head. Therefore, it is suggested that this behavior is mainly due to the coupled dependence of the layer saturated hydraulic conductivities and the shape factors on the texture and bulk density. The correlation between the soil grain diameter and bulk density decreases the anisotropy effects of the unsaturated layered soils. The study illustrates that the inter-relationships of soil texture, bulk density, and hydraulic properties may cause vastly different characteristics of anisotropic unsaturated soils.

  19. Intracranial blood flow measured with single photon emission computer tomography (SPECT) during transient -6 degrees head-down tilt.

    Science.gov (United States)

    Satake, H; Konishi, T; Kawashima, T; Matsunami, K; Uno, T; Imai, S; Yamada, H; Hirakawa, C

    1994-02-01

    Regional cerebral blood flow (CBF) during a transient head-down tilt of -6 degrees (-6 degrees HDT) was measured with single photon emission computer tomography (SPECT). CBF was measured and averaged for both sides of the brain areas; e.g., the bilateral anterior cerebral artery (bACA) area, the middle cerebral artery (bMCA) area, the posterior cerebral artery (bPCA) area, bilateral basal ganglia, and the cerebellum. Among these areas, a significant increase in CBF was observed in the basal ganglia and the cerebellum during -6 degrees HDT compared to pre-HDT. When CBF was measured separately in the left or right brain area, these significances disappeared, although a trend of increase or decrease was still observable. A trend of increase was observed in the left anterior cerebral artery (IACA) area, the right middle cerebral artery (rMCA) area, the right posterior cerebral artery (rPCA) area, the left and right basal ganglia, and the cerebellum. In rACA, IMCA and IPCA areas, a slight decrease in CBF was observed. At the same time, cardiac parameters were measured. Heart rate (HR), stroke volume (SV) and cardiac output (CO) did not change significantly, although SV slightly increased and HR slightly decreased during -6 degrees HDT.

  20. Pretreatment organ function in patients with advanced head and neck cancer: clinical outcome measures and patients' views

    Directory of Open Access Journals (Sweden)

    Rasch Coen RN

    2009-11-01

    Full Text Available Abstract Background Aim of this study is to thoroughly assess pretreatment organ function in advanced head and neck cancer through various clinical outcome measures and patients' views. Methods A comprehensive, multidimensional assessment was used, that included quality of life, swallowing, mouth opening, and weight changes. Fifty-five patients with stage III-IV disease were entered in this study prior to organ preserving (chemoradiation treatment. Results All patients showed pretreatment abnormalities or problems, identified by one or more of the outcome measures. Most frequent problems concerned swallowing, pain, and weight loss. Interestingly, clinical outcome measures and patients' perception did no always concur. E.g. videofluoroscopy identified aspiration and laryngeal penetration in 18% of the patients, whereas only 7 patients (13% perceived this as problematic; only 2 out of 7 patients with objective trismus actually perceived trismus. Conclusion The assessment identified several problems already pre-treatment, in this patient population. A thorough assessment of both clinical measures and patients' views appears to be necessary to gain insight in all (perceived pre-existing functional and quality of life problems.

  1. First measurement of nuclear recoil head-tail sense in a fiducialised WIMP dark matter detector

    CERN Document Server

    Battat, J B R; Ezeribe, A C; Gauvreau, J -L; Harton, J L; Lafler, R; Lee, E R; Loomba, D; Lumnah, A; Miller, E H; Mouton, F; Murphy, A StJ; Paling, S M; Phan, N S; Robinson, M; Sadler, S W; Scarff, A; Schuckman, F G; Snowden-Ifft, D P; Spooner, N J C

    2016-01-01

    Recent computational results suggest that directional dark matter detectors have potential to probe for WIMP dark matter particles below the neutrino floor. The DRIFT-IId detector used in this work is a leading directional WIMP search time projection chamber detector. We report the first measurements of the detection of the directional nuclear recoils in a fully fiducialised low-pressure time projection chamber. In this new operational mode, the distance between each event vertex and the readout plane is determined by the measurement of minority carriers produced by adding a small amount of oxygen to the nominal CS$_{2}$ + CF$_{4}$ target gas mixture. The CS$_2$ + CF$_4$ + O$_2$ mixture has been shown to enable background-free operation at current sensitivities. Sulfur, fluorine, and carbon recoils were generated using neutrons emitted from a $^{252}$Cf source positioned at different locations around the detector. Measurement of the relative energy loss along the recoil tracks allowed the track vector sense, ...

  2. Measuring culture outside the head: a meta-analysis of individualism-collectivism in cultural products.

    Science.gov (United States)

    Morling, Beth; Lamoreaux, Marika

    2008-08-01

    Although cultural psychology is the study of how sociocultural environments and psychological processes coconstruct each other, the field has traditionally emphasized measures of the psychological over the sociocultural. Here, the authors call attention to a growing trend of measuring the sociocultural environment. They present a quantitative review of studies that measure cultural differences in "cultural products": tangible, public representations of culture such as advertising or popular texts. They found that cultural products that come from Western cultures (mostly the United States) are more individualistic, and less collectivistic, than cultural products that come from collectivistic cultures (including Korea, Japan, China, and Mexico). The effect sizes for cultural products were larger than self-report effect sizes for this dimension (reported in Oyserman, Coon, & Kemmelmeier, 2002). In addition to presenting this evidence, the authors highlight the importance of studying the dynamic relationships between sociocultural environments and psyches.

  3. Midsagittal surface measurement of the head: an assessment of craniofacial asymmetry

    Science.gov (United States)

    Christensen, Gary E.; Johnson, Hans J.; Darvann, Tron; Hermann, Nuno; Marsh, Jeffrey L.

    1999-05-01

    Left/right craniofacial asymmetry is typically measured by comparing distances between standard anatomical landmarks. However, these measurements are of limited use for visualizing and quantifying the asymmetry at non-landmark locations. This work presents a method for calculating, measuring and visualizing the planar deviation of the midsagittal surface for the purpose of craniofacial dysmorphology assessment, pre-operative corrective surgery planning, and post-operative evaluation. A set of midsagittal landmarks are used to define a reference midsagittal plane and to define a non-planar surface that passes through the landmarks. The surface is modeled as a thin-plate spline that can be visualized in 3D using a virtual reality markup language browser and it can be fused with the original volume rendered CT data using VoxelViewTM.

  4. Laser Doppler flowmetry for bone blood flow measurement: correlation with microsphere estimates and evaluation of the effect of intracapsular pressure on femoral head blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Swiontkowski, M.F.; Tepic, S.; Perren, S.M.; Moor, R.; Ganz, R.; Rahn, B.A.

    1986-01-01

    Laser Doppler flowmetry (LDF) was used to measure bone blood flow in the rabbit femoral condyles. To correlate the LDF output signal blood cell flux to in vivo blood flow, simultaneous measurements using LDF and /sup 85/Sr-labeled microspheres were made in an adult rabbit model. There was no correlation between the two methods for blood flow in the femoral condyles and the correlation between the two methods for blood flow in the femoral head does not achieve statistical significance. An LDF signal of 0.4 V was approximately equal to a microsphere measured flow rate of 0.4 ml blood/g bone/min. The strength of the correlation in the latter case may have been affected by (a) large arteriovenous shunts, (b) inadequate mixing of the microspheres with a left ventricular injection, and (c) insufficient numbers of microspheres present in the bone samples. When LDF was used to evaluate the effect of elevated intracapsular pressure on femoral head blood flow in skeletally mature rabbits, femoral head subchondral bone blood flow declined with increasing intracapsular pressure from a baseline value of 0.343 +/- 0.036 to a value of 0.127 +/- 0.27 at 120 cm of water pressure. The decline in femoral head blood flow was statistically significant at pressures of 40 cm of water or higher (p less than 0.001), and evaluation of sections of the proximal femora made from preterminal disulphine blue injections confirmed these findings. Intracapsular tamponade has an adverse effect on femoral head blood flow beginning well below central venous pressure and should be considered in the pathophysiology of posttraumatic and nontraumatic necrosis of the femoral head. Laser Doppler flowmetry was easy to use and appears to be a reproducible technique for evaluating femoral head blood flow, offering distinct advantages over the microsphere technique for measuring bone blood flow.

  5. Noninvasive determination of absorption and reduced scattering coefficients of adult heads by time-resolved reflectance measurements for functional near infra-red spectroscopy.

    Science.gov (United States)

    Tanifuji, T; Wang, L

    2014-01-01

    Absorption and reduced scattering coefficients (μ(a) and μ'(s)) of adult heads have been noninvasively determined by time-resolved reflectance measurements. The finite difference time domain (FDTD) analysis was used to calculate time-resolved reflectance from realistic adult head models with brain grooves containing a non-scattering layer. In vivo time-resolved reflectances of human heads were measured by a system composed of a time-correlated single photon counter and a diode laser. By minimizing the objective functions that compare theoretical and experimental time resolved reflectances, μ(a) and μ'(s) of brain were determined. It became clear that time-resolved measurements have enough sensitivity to determine both μ(a) and μ'(s) for superficial tissues, gray matter and white matter, except μ(s) for white matter.

  6. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  7. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  8. Single-Molecule Measurement of the Stiffness of the Rigor Myosin Head

    OpenAIRE

    2007-01-01

    The force-extension curve of single myosin subfragment-1 molecules, interacting in the rigor state with an actin filament, has been investigated at low [ATP] by applying a slow triangle-wave movement to the optical traps holding a bead-actin-bead dumbbell. In combination with a measurement of the overall stiffness of the dumbbell, this allowed characterization of the three extensible elements, the actin-bead links and the myosin. Simultaneously, another method, based on an analysis of bead po...

  9. Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

    Directory of Open Access Journals (Sweden)

    Javier Valdes-Abellan

    2015-03-01

    Full Text Available Abstract Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i non-automatic and more time-consuming; ii automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic. Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm. Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher.

  10. Comparison among monitoring strategies to assess water flow dynamic and soil hydraulic properties in agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Valdes-Abellan, J.; Jiménez-Martínez, J.; Candela, L.; Tamoh, K.

    2015-07-01

    Irrigated agriculture is usually performed in semi-arid regions despite scarcity of water resources. Therefore, optimal irrigation management by monitoring the soil is essential, and assessing soil hydraulic properties and water flow dynamics is presented as a first measure. For this purpose, the control of volumetric water content, θ, and pressure head, h, is required. This study adopted two types of monitoring strategies in the same experimental plot to control θ and h in the vadose zone: i) non-automatic and more time-consuming; ii) automatic connected to a datalogger. Water flux was modelled with Hydrus-1D using the data collected from both acquisition strategies independently (3820 daily values for the automatic; less than 1000 for the non-automatic). Goodness-of-fit results reported a better adjustment in case of automatic sensors. Both model outputs adequately predicted the general trend of θ and h, but with slight differences in computed annual drainage (711 mm and 774 mm). Soil hydraulic properties were inversely estimated from both data acquisition systems. Major differences were obtained in the saturated volumetric water content, θs, and the n and α van Genuchten model shape parameters. Saturated hydraulic conductivity, Ks, shown lower variability with a coefficient of variation range from 0.13 to 0.24 for the soil layers defined. Soil hydraulic properties were better assessed through automatic data acquisition as data variability was lower and accuracy was higher. (Author)

  11. The stability of source localization in a whole-head magnetoencephalography system demonstrated by auditory evoked field measurements

    Science.gov (United States)

    Chen, Kuen-Lin; Yang, Hong-Chang; Tsai, Sung-Ying; Liu, Yu-Wei; Liao, Shu-Hsien; Horng, Herng-Er; Lee, Yong-Ho; Kwon, Hyukchan

    2011-10-01

    Superconducting quantum interference device (SQUID), which is a very sensitive magnetic sensor, has been widely used to detect the ultra-small magnetic signals in many different territories, especially in the biomagnetic measurement. In this study, a 128-channel SQUID first-order axial gradiometer system for whole-head magnetoencephalography (MEG) measurements was setup to characterize the auditory evoked magnetic fields (AEFs). A 500 Hz monaural pure tone persisting 425 ms with the sound pressure level of 80 dB was randomly applied to the left ear of subject with the inter-stimulus interval of 1.5 ˜ 2.8 s to prevent fatigue of nerves. We demonstrated the characteristic waveforms of AEFs can be accurately recorded and analyzed. Using source localization processes, the origins of AEFs were successfully calculated to be at the auditory cortices which are brain areas known for responsive to sound stimulus. A phantom experiment also proved the good localization accuracy of the established MEG system and measurement procedures. The validated performance of the SQUID system suggests that this technique can also be employed in other brain research.

  12. Joint assimilation of piezometric heads and groundwater temperatures for improved modelling of river-aquifer interactions

    Science.gov (United States)

    Kurtz, Wolfgang; Hendricks-Franssen, Harrie-Jan; Vereecken, Harry

    2013-04-01

    Measured groundwater temperatures close to streams contain valuable information for the assessment of mass transfer rates between river and aquifer and the hydraulic properties around a streambed. For groundwater management close to rivers, the characterization of these hydraulic properties is of special interest because exchange fluxes between river and aquifer influence the sustainability of groundwater abstraction and the quality of pumped drinking water. Additionally, it can be important for groundwater management to gain reliable predictions of groundwater temperatures, e.g. in order to regulate the temperature of extracted drinking water. Data assimilation techniques, like the ensemble Kalman filter (EnKF), provide a flexible stochastic framework to merge model simulations with different types of measurement data in order to enhance the (real-time) prediction of groundwater states and to improve the estimation of uncertain hydraulic subsurface parameters. EnKF has already been used for managed river-aquifer systems to improve the prediction of groundwater levels and the estimation of hydraulic parameters by the assimilation of measured piezometric head data. As temperature data can provide additional information on stream-aquifer exchange it is investigated whether this information further constrains states, fluxes and parameters of the river-groundwater system. For this purpose, we performed data assimilation experiments with two different model setups: (i) a simple synthetic model of a river-aquifer system where the parameters and simulation conditions were perfectly known (ii) a more complex model of the Limmat aquifer in Zurich where real-world data were assimilated. Results for the synthetic case suggest that a joint assimilation of piezometric heads and groundwater temperatures together with updating of uncertain hydraulic conductivities and leakage coefficients gives the best estimation of states, fluxes and hydraulic properties (i.e., hydraulic

  13. Is inversion based high resolution characterization of spatially heterogeneous river bed hydraulic conductivity needed and possible?

    Directory of Open Access Journals (Sweden)

    W. Kurtz

    2013-05-01

    others. In case of less heterogeneous river bed hydraulic conductivities, a high-resolution characterization of L is less important. We conclude that for strongly heterogeneous river beds the commonly applied simplified representation of the streambed, with spatially homogeneous parameters or constant parameters for a few zones, might yield significant biases in the characterization of the water balance. For strongly heterogeneous river beds, we suggest to adopt a stochastic field approach to model the spatially heterogeneous river beds geostatistically. The paper illustrates that EnKF is able to calibrate such heterogeneous streambeds on the basis of hydraulic head measurements, outperforming classical approaches.

  14. Quantitative head ultrasound measurements to determine thresholds for preterm neonates requiring interventional therapies following intraventricular hemorrhage

    Science.gov (United States)

    Kishimoto, Jessica; Fenster, Aaron; Salehi, Fateme; Romano, Walter; Lee, David S. C.; de Ribaupierre, Sandrine

    2016-04-01

    Dilation of the cerebral ventricles is a common condition in preterm neonates with intraventricular hemorrhage (IVH). This post hemorrhagic ventricle dilation (PHVD) can lead to lifelong neurological impairment through ischemic injury due to increased intracranial pressure and without treatment, can lead to death. Clinically, 2D ultrasound (US) through the fontanelles ('soft spots') of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up cerebrospinal fluid (CSF) ('ventricle tap', VT) might be indicated for a patient; however, quantitative measurements of the growth of the ventricles are often not performed. There is no consensus on when a neonate with PHVD should have an intervention and often interventions are performed after the potential for brain damage is quite high. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. We will describe the potential utility of quantitative 2D and 3D US to monitor and manage PHVD in neonates. Specifically, we will look to determine image-based measurement thresholds for patients who will require VT in comparison to patients with PHVD who resolve without intervention. Additionally, since many patients who have an initial VT will require subsequent interventions, we look at the potential for US to determine which PHVD patients will require additional VT after the initial one has been performed.

  15. A hybrid inverse method for hydraulic tomography in fractured and karstic media

    Science.gov (United States)

    Wang, Xiaoguang; Jardani, Abderrahim; Jourde, Hervé

    2017-08-01

    We apply a stochastic Newton (SN) approach to solve a high-dimensional hydraulic inverse problem in highly heterogeneous geological media. By recognizing the connection between the cost function of deterministic optimizations and the posterior probability density of stochastic inversions, the Markov chain Monte Carlo (MCMC) sampler of SN is constructed by two parts: a deterministic part, which corresponds to a Newton step of deterministic optimization, and a stochastic part, which is a Gaussian distribution with the inverse of the local Hessian as the covariance matrix. The hybrid inverse method exploits the efficient tools for fast solution of deterministic inversions to improve the efficiency of the MCMC sampler. To address the ill-posedness of the inverse problem, a priori models, generated by a transition-probability geostatistical method, and conditioned to inter-well connection data, are used as regularization constraints. The effectiveness of the stochastic Newton method is first demonstrated by a synthetic test. The transmissivity field of the synthetic model is highly heterogeneous, and includes sharp variations. The inverse approach was then applied to a field hydraulic tomography investigation in a fractured and karstified aquifer to reconstruct its transmissivity field from a collection of real hydraulic head measurements. From the inversions, a series of transmissivity fields that produce good correlations between the inverted and the measured hydraulic heads were obtained. The inverse approach produced slightly different a posteriori transmissivity patterns for different a priori structure models of transmissivity; however, the trend and location of the high-transmissivity channels are consistent among various realizations. In addition, the uncertainty associated with each realization of the inverted transmissivity fields was quantified.

  16. Visual Contribution to Speech Perception: Measuring the Intelligibility of Animated Talking Heads

    Directory of Open Access Journals (Sweden)

    Slim Ouni

    2006-10-01

    Full Text Available Animated agents are becoming increasingly frequent in research and applications in speech science. An important challenge is to evaluate the effectiveness of the agent in terms of the intelligibility of its visible speech. In three experiments, we extend and test the Sumby and Pollack (1954 metric to allow the comparison of an agent relative to a standard or reference, and also propose a new metric based on the fuzzy logical model of perception (FLMP to describe the benefit provided by a synthetic animated face relative to the benefit provided by a natural face. A valid metric would allow direct comparisons accross different experiments and would give measures of the benfit of a synthetic animated face relative to a natural face (or indeed any two conditions and how this benefit varies as a function of the type of synthetic face, the test items (e.g., syllables versus sentences, different individuals, and applications.

  17. Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

    Science.gov (United States)

    Congsheng Fu; Guiling Wang; Michael L. Goulden; Russell L. Scott; Kenneth Bible; Zoe G. Cardon

    2016-01-01

    Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site...

  18. A novel energy recovery system for parallel hybrid hydraulic excavator.

    Science.gov (United States)

    Li, Wei; Cao, Baoyu; Zhu, Zhencai; Chen, Guoan

    2014-01-01

    Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the proposed energy recovery system is calculated based on the mathematical models. Meanwhile, the simulation models of the proposed system and a conventional energy recovery system are built by AMESim software. The results show that the proposed system is more effective than the conventional energy saving system. At last, the main components of the proposed energy recovery system including accumulator and hydraulic motor are analyzed for improving the energy recovery efficiency. The measures to improve the energy recovery efficiency of the proposed system are presented.

  19. US Findings of Biceps Tendinitis: Cross Sectional Area Measurements of Long Head of Biceps Brachii

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jong Soo; Seo, Kyung Mook; Lee, Hwa Yeon; Song, In Sup [ChungAng University College of Medicine, Seoul (Korea, Republic of); Yoo, Seung Min [Bundang Cha Hospital, Bundang (Korea, Republic of)

    2009-12-15

    The purpose of this study was to describe typical sonographic findings in patients with biceps tendinitis. Seventy five patients who had been clinically diagnosed with biceps tendinitis were included. Of the 75, 37 were male, 38 were female, and their mean age was 56 {+-} 9.74. The patients complained of shoulder pain and ultrasonography was performed for bilateral shoulders in all patients. The cross sectional area of the biceps tendon was measured. The status of fluid collection around the biceps tendon and accompanying rotator cuff disease were also investigated. The cross sectional areas of the diseased biceps tendon were 0.18 {+-} 0.09 cm2 (range: 0.07-0.42), and the areas of the normal side was 0.11 {+-} 0.05 cm2 (0.03-0.24). The cross sectional area of the diseased biceps tendon was 0.075 {+-} 0.062 cm2 greater, on average, than the uninvolved site (p < 0.01). Thirty six patients(48%) had fluid collection around the inflamed biceps tendon, and 30 patients had accompanied rotator cuff disease. During US examination of the shoulder in patients complaining of shoulder pain, if the cross sectional area of the biceps tendon in the painful shoulder is asymmetrically and larger than the contralateral tendon, biceps tendonitis is suggested

  20. A step towards measuring the fetal head circumference with the use of obstetric ultrasound in a low resource setting

    Science.gov (United States)

    van den Heuvel, Thomas L. A.; Petros, Hezkiel; Santini, Stefano; de Korte, Chris L.; van Ginneken, Bram

    2017-03-01

    Worldwide, 99% of all maternal deaths occur in low-resource countries. Ultrasound imaging can be used to detect maternal risk factors, but requires a well-trained sonographer to obtain the biometric parameters of the fetus. One of the most important biometric parameters is the fetal Head Circumference (HC). The HC can be used to estimate the Gestational Age (GA) and assess the growth of the fetus. In this paper we propose a method to estimate the fetal HC with the use of the Obstetric Sweep Protocol (OSP). With the OSP the abdomen of pregnant women is imaged with the use of sweeps. These sweeps can be taught to somebody without any prior knowledge of ultrasound within a day. Both the OSP and the standard two-dimensional ultrasound image for HC assessment were acquired by an experienced gynecologist from fifty pregnant women in St. Luke's Hospital in Wolisso, Ethiopia. The reference HC from the standard two-dimensional ultrasound image was compared to both the manually measured HC and the automatically measured HC from the OSP data. The median difference between the estimated GA from the manual measured HC using the OSP and the reference standard was -1.1 days (Median Absolute Deviation (MAD) 7.7 days). The median difference between the estimated GA from the automatically measured HC using the OSP and the reference standard was -6.2 days (MAD 8.6 days). Therefore, it can be concluded that it is possible to estimate the fetal GA with simple obstetric sweeps with a deviation of only one week.

  1. Head pulsations in a centrifugal pump

    Science.gov (United States)

    Boiko, V. S.; Sotnyk, M. I.; Moskalenko, V. V.

    2017-08-01

    This article investigated the factors, which affect to the character of the head pulsations of a centrifugal pump. We investigated the dependence of the shape and depth of these pulsations from the operation mode of the pump. Was determined, that the head pulsations at the outlet of the impeller (pulsations on the blade passing frequency) cause head pulsations at the outlet of the pump, that have the same frequency, but differ in shape and depth. These pulsations depend on the design features of the flow-through part of the pump (from the ratio of hydraulic losses on the friction and losses on the vortex formation). A feature of the researches that were conducted is also the using of not only hydraulic but also electric modeling methods. It allows determining the values of the components of hydraulic losses.

  2. Comparison of optic area measurement using fundus photography and optical coherence tomography between optic nerve head drusen and control subjects.

    Science.gov (United States)

    Flores-Rodríguez, Patricia; Gili, Pablo; Martín-Ríos, María Dolores; Grifol-Clar, Eulalia

    2013-03-01

    To compare optic disc area measurement between optic nerve head drusen (ONHD) and control subjects using fundus photography, time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT). We also made a comparison between each of the three techniques. We performed our study on 66 eyes (66 patients) with ONHD and 70 healthy control subjects (70 controls) with colour ocular fundus photography at 20º (Zeiss FF 450 IR plus), TD-OCT (Stratus OCT) with the Fast Optic Disc protocol and SD-OCT (Cirrus OCT) with the Optic Disc Cube 200 × 200 protocol for measurement of the optic disc area. The measurements were made by two observers and in each measurement a correction of the image magnification factor was performed. Measurement comparison using the Student's t-test/Mann-Whitney U test, the intraclass correlation coefficient, Pearson/Spearman rank correlation coefficient and the Bland-Altman plot was performed in the statistical analysis. Mean and standard deviation (SD) of the optic disc area in ONHD and in controls was 2.38 (0.54) mm(2) and 2.54 (0.42) mm(2), respectively with fundus photography; 2.01 (0.56) mm(2) and 1.66 (0.37) mm(2), respectively with TD-OCT, and 2.03 (0.49) mm(2) and 1.75 (0.38) mm(2), respectively with SD-OCT. In ONHD and controls, repeatability of optic disc area measurement was excellent with fundus photography and optical coherence tomography (TD-OCT and SD-OCT), but with a low degree of agreement between both techniques. Optic disc area measurement is smaller in ONHD compared to healthy subjects with fundus photography, unlike time-domain and spectral-domain optical coherence tomography in which the reverse is true. Both techniques offer good repeatability, but a low degree of correlation and agreement, which means that optic disc area measurement is not interchangeable or comparable between techniques. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  3. Comparison of measurements from digital cephalometric radiographs and 3D MDCT-synthetized cephalometric radiographs and the effect of head position

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Ja; Choi, Bo Ram; Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2009-09-15

    To investigate the reproducibilities and compare the measurements in digital and MDCT-synthesized cephalometric radiograph, and to investigate the effect of head position on the measurement during imaging with MDCT. Twenty-two dry skulls (combined with mandible) were used in this study. Conventional digital cephalometric radiograph was taken in standard position, and MDCT was taken in standard position and two rotated position (10 .deg. C left rotation and 10 .deg. C right tilting). MDCT data were imported in OnDemand and lateral cephalometric radiograph were synthesized from 3D virtual models. Two types of rotated MDCT data were synthesized with default mode and with corrected mode using both ear rods. For all six images, sixteen angular and eleven linear measurements were made in V-Ceph three times. Reproducibility of measurements was assessed using repeated measures ANOVA and ICC. Linear and angular measurements were compared between digital and five MDCTsynthesized images by Student t-test. All measurements in six types of cephalometric radiograph were not statistically different under ICC examination. Measurements were not different between digital and MDCT-synthesized images (P> .05). Measurements in MDCT-synthesized image in 10 .deg. C left rotation or 10 .deg. C right tilting position showed possibility of difference from digital image in some measurements, and possibility of improvement via realignment of head position using both ear rods. MDCT-synthesized cephalometric radiograph can substitute conventional cephalometric radiograph. The error on head position during imaging with MDCT have possibility that can produce measurement errors with MDCT-synthesized image, and these position error can be corrected by realignment of the head position using both ear rods.

  4. The influence of hydraulic forces on the selection of structural form

    NARCIS (Netherlands)

    Glerum, A.; Schippers, J.

    1981-01-01

    Besides that the hydraulic forces have an influence on the structure, the shape of the structure may often influence the hydraulic loads as well. A distinction should be made between hydrostatic forces which are for instance caused by a difference in head between two water levels and dynamic forces

  5. Root water extraction and limiting soil hydraulic conditions estimated by numerical simulation

    NARCIS (Netherlands)

    Jong van Lier, de Q.; Metselaar, K.; Dam, van J.C.

    2006-01-01

    Root density, soil hydraulic functions, and hydraulic head gradients play an important role in the determination of transpiration-rate-limiting soil water contents. We developed an implicit numerical root water extraction model to solve the Richards equation for the modeling of radial root water

  6. Drawing a pictogram operator - hydraulic stowing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Bukhgol' ts, V.P.; Dinershtein, V.A.

    1984-11-01

    Hydraulic stowing is widely used during the extraction of coal from seams prone to spontaneous ignition or from seams situated under preserved structures. Experience has shown that the presence of a considerable number of controlling and measuring devices on hydraulic stowing assemblies results in erratic operations. The authors, after examining the controls of the hydraulic stowing complexes, recommend that all functions which the operator might perform badly or not at all should be controlled automatically. The operator must, however, have access to manual controls which should be included in the system in order to achieve an effective and trouble free operation. The authors propose a pictogram to explain the relationship between the human operator and the hydraulic complex, based on structural diagrams. The system developed, which was tried out at the Koksovaya mine, increased the efficiency of the complex and reduced the work load of the operator. 3 references.

  7. FEMA DFIRM Hydraulic Structures

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer and accompanying attribute table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the...

  8. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on......-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical...... modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research...

  9. Estimating of larval stadia of West Indian sweetpotato weevil Euscepes postfasciatus (Fairmaire) developed in the artificial larval diet by measuring larval head widths.

    OpenAIRE

    下地, 幸夫; Shimoji, Yukio; 琉球産経株式会社

    2003-01-01

    The survey conducted by measuring larval head widths of West Indian sweetpotato weevil Euscepes postfasciatus developed in the artificial larval diet revealed that there were five larval stadia in the developmental period. The result of this experiment can be used to estimate the larval stadia approximately in the artificial larval diet.

  10. Constant-Pressure Hydraulic Pump

    Science.gov (United States)

    Galloway, C. W.

    1982-01-01

    Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

  11. Impact of in-scanner head motion on multiple measures of functional connectivity: relevance for studies of neurodevelopment in youth.

    Science.gov (United States)

    Satterthwaite, Theodore D; Wolf, Daniel H; Loughead, James; Ruparel, Kosha; Elliott, Mark A; Hakonarson, Hakon; Gur, Ruben C; Gur, Raquel E

    2012-03-01

    It has recently been reported (Van Dijk et al., 2011) that in-scanner head motion can have a substantial impact on MRI measurements of resting-state functional connectivity. This finding may be of particular relevance for studies of neurodevelopment in youth, confounding analyses to the extent that motion and subject age are related. Furthermore, while Van Dijk et al. demonstrated the effect of motion on seed-based connectivity analyses, it is not known how motion impacts other common measures of connectivity. Here we expand on the findings of Van Dijk et al. by examining the effect of motion on multiple types of resting-state connectivity analyses in a large sample of children and adolescents (n=456). Following replication of the effect of motion on seed-based analyses, we examine the influence of motion on graphical measures of network modularity, dual-regression of independent component analysis, as well as the amplitude and fractional amplitude of low frequency fluctuation. In the entire sample, subject age was highly related to motion. Using a subsample where age and motion were unrelated, we demonstrate that motion has marked effects on connectivity in every analysis examined. While subject age was associated with increased within-network connectivity even when motion was accounted for, controlling for motion substantially attenuated the strength of this relationship. The results demonstrate the pervasive influence of motion on multiple types functional connectivity analysis, and underline the importance of accounting for motion in studies of neurodevelopment. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Similar head impact acceleration measured using instrumented ear patches in a junior rugby union team during matches in comparison with other sports.

    Science.gov (United States)

    King, Doug A; Hume, Patria A; Gissane, Conor; Clark, Trevor N

    2016-07-01

    OBJECTIVE Direct impact with the head and the inertial loading of the head have been postulated as major mechanisms of head-related injuries, such as concussion. METHODS This descriptive observational study was conducted to quantify the head impact acceleration characteristics in under-9-year-old junior rugby union players in New Zealand. The impact magnitude, frequency, and location were collected with a wireless head impact sensor that was worn by 14 junior rugby players who participated in 4 matches. RESULTS A total of 721 impacts > 10g were recorded. The median (interquartile range [IQR]) number of impacts per player was 46 (IQR 37-58), resulting in 10 (IQR 4-18) impacts to the head per player per match. The median impact magnitudes recorded were 15g (IQR 12g-21g) for linear acceleration and 2296 rad/sec(2) (IQR 1352-4152 rad/sec(2)) for rotational acceleration. CONCLUSIONS There were 121 impacts (16.8%) above the rotational injury risk limit and 1 (0.1%) impact above the linear injury risk limit. The acceleration magnitude and number of head impacts in junior rugby union players were higher than those previously reported in similar age-group sports participants. The median linear acceleration for the under-9-year-old rugby players were similar to 7- to 8-year-old American football players, but lower than 9- to 12-year-old youth American football players. The median rotational accelerations measured were higher than the median and 95th percentiles in youth, high school, and collegiate American football players.

  13. The puzzle of high heads beneath the West Cumbrian coast, UK: a possible solution

    Science.gov (United States)

    Black, John H.; Barker, John A.

    2016-03-01

    A region of high heads within the Borrowdale Volcanic Group (BVG; a fractured crystalline rock) beneath the coastal plain of West Cumbria, England (UK), is identified as a possible relic left over by the Late Devensian ice sheet. It was found during investigations in the 1990s. Contemporary modelling work failed to produce a satisfactory explanation of the high heads compatible with the `cold recharge' isotopic signature of the groundwater. This study has reassessed the original hydraulic testing results. By plotting density-adjusted heads versus their depth below the water table in the immediate vicinity of the borehole in which they were measured, a depth profile resembling a `wave' was revealed with a peak value located at 1,100 m depth. The possibility that this wave represents relic heads from the last major ice sheet has been assessed using one-dimensional mathematical analysis based on a poroelastic approach. It is found that a wet-based ice sheet above the West Cumbrian coast was probably thick enough and sufficiently long-lasting to leave such relic heads providing that the hydraulic diffusivity of the BVG is in the order of 10-6 m s-1. Initial assessment 20 years ago of the long-interval slug tests suggested that such low values are not likely. More recent interpretation argues for such low values of hydraulic diffusivity. It is concluded that ice sheet recharge is the most likely cause of the raised heads, that the BVG contains significant patches of very low conductivity rock, and that long-interval single-hole tests should be avoided in fractured crystalline rock.

  14. Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2013-09-01

    Full Text Available INTRODUCTION: Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. AIM: The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. METHODS: Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a gray levels produced by the bone x-ray absorption, b the portions of the image occupied by air and c voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. RESULTS: The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

  15. A Space Weather Information Service Based Upon Remote and In-Situ Measurements of Coronal Mass Ejections Heading for Earth

    CERN Document Server

    Ritter, Birgit; Miles, Oscar; Rußwurm, Michael; Scully, Stephen; Roldán, Andrés; Hartkorn, Oliver; Jüstel, Peter; Réville, Victor; Lupu, Sorina; Ruffenach, Alexis

    2015-01-01

    The Earth's magnetosphere is formed as a consequence of interaction between the planet's magnetic field and the solar wind, a continuous plasma stream from the Sun. A number of different solar wind phenomena have been studied over the past forty years with the intention of understanding and forecasting solar behavior. One of these phenomena in particular, Earth-bound interplanetary coronal mass ejections (CMEs), can significantly disturb the Earth's magnetosphere for a short time and cause geomagnetic storms. This publication presents a mission concept consisting of six spacecraft that are equally spaced in a heliocentric orbit at 0.72 AU. These spacecraft will monitor the plasma properties, the magnetic field's orientation and magnitude, and the 3D-propagation trajectory of CMEs heading for Earth. The primary objective of this mission is to increase space weather (SW) forecasting time by means of a near real-time information service, that is based upon in-situ and remote measurements of the aforementioned CM...

  16. Postural Control Characteristics during Single Leg Standing of Individuals with a History of Ankle Sprain: Measurements Obtained Using a Gravicorder and Head and Foot Accelerometry.

    Science.gov (United States)

    Abe, Yota; Sugaya, Tomoaki; Sakamoto, Masaaki

    2014-03-01

    [Purpose] This study aimed to validate the postural control characteristics of individuals with a history of ankle sprain during single leg standing by using a gravicorder and head and foot accelerometry. [Subjects] Twenty subjects with and 23 subjects without a history of ankle sprain (sprain and control groups, respectively) participated. [Methods] The anteroposterior, mediolateral, and total path lengths, as well as root mean square (RMS) of each length, were calculated using the gravicorder. The anteroposterior, mediolateral, and resultant acceleration of the head and foot were measured using accelerometers and were evaluated as the ratio of the acceleration of the head to the foot. [Results] There was no significant difference between the two groups in path length or RMS acceleration of the head and foot. However, the ratios of the mediolateral and resultant components were significantly higher in the sprain group than in the control group. [Conclusion] Our findings suggest that individuals with a history of ankle sprain have a higher head-to-foot acceleration ratio and different postural control characteristics than those of control subjects.

  17. Compensation Method of Natural Head Movement for Gaze Tracking System Using an Ultrasonic Sensor for Distance Measurement.

    Science.gov (United States)

    Jung, Dongwook; Lee, Jong Man; Gwon, Su Yeong; Pan, Weiyuan; Lee, Hyeon Chang; Park, Kang Ryoung; Kim, Hyun-Cheol

    2016-01-16

    Most gaze tracking systems are based on the pupil center corneal reflection (PCCR) method using near infrared (NIR) illuminators. One advantage of the PCCR method is the high accuracy it achieves in gaze tracking because it compensates for the pupil center position based on the relative position of corneal specular reflection (SR). However, the PCCR method only works for user head movements within a limited range, and its performance is degraded by the natural movement of the user's head. To overcome this problem, we propose a gaze tracking method using an ultrasonic sensor that is robust to the natural head movement of users. Experimental results demonstrate that with our compensation method the gaze tracking system is more robust to natural head movements compared to other systems without our method and commercial systems.

  18. Blood flow and blood volume in the femoral heads of healthy adults according to age. Measurement with positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Toshikazu; Kimori, Kokuto; Nakamura, Fuminori; Inoue, Shigehiro; Fujioka, Mikihiro; Ueshima, Keiichiro; Hirasawa, Yasusuke; Ushijima, Yo; Nishimura, Tsunehiko [Kyoto Prefectural Univ. of Medicine (Japan)

    2001-06-01

    To deepen understanding of hemodynamics in the femoral head, i.e., the essential factor in clarifying pathogenesis of hip disorders, this study examined blood flow and blood volume in the femoral heads of healthy adults, and their changes with age, by using positron emission tomography (PET). In 16 healthy adult males (age: 20-78 years old, mean age: 42 years), blood flow was measured by means of the H{sub 2}{sup 15}O dynamic study method, and blood volume was measured by means of the {sup 15}O-labeled carbon monoxide bolus inhalation method. Blood flow was 1.68-6.47 ml/min/100 g (mean {+-}SD: 3.52{+-}1.2), and blood volume was 1.67-6.03 ml/100 g (mean {+-}SD: 3.00{+-}1.27). Blood flow significantly decreased (p<0.01) with age, and blood volume significantly increased (P<0.05). PET was useful in the measurement of blood flow and blood volume in the femoral heads. With age, physiological hemodynamic changes also increased in femoral heads. (author)

  19. 井下工具拆装架主钳转矩测量方法及误差分析%Analysis of Torque Measurement Error and Method of Major Power Tongs for Downhole Tool Hydraulic Torque Equipment

    Institute of Scientific and Technical Information of China (English)

    章发明; 温平; 杜青忠; 王东

    2013-01-01

    The downhole tools to making-up and breakout using hydraulic device and torque measurement and control are implemented with main tong.Force arm tong is driven by hydraulic torque,with the length of force arm changing with turning angle.The calculation of the force arm is done by using actual measurement of torque,which produces error.The gear rack is pushed by hydraulic cylinder in type of gear wheel and gear wheel tong.The torque is built when gear rack driving gear wheel.The force to turn gear wheel is by wheel radius,so the measurement error by the torque is something related to the instrument precision.The new type of gear-wheel-and-rack tong gives real-time measure and control,and the accurate measurement is obtained.%液压拆装架用于井下工具螺纹的上紧和卸扣,转矩的测量和控制是通过主钳来完成.力臂式主钳是由液缸推动传力杆产生转矩,力臂的长度随转角而变,实际测量转矩时是取定长力臂进行计算,因此误差较大.齿轮齿条式主钳是由液缸推动齿条,齿条带动拧扣大齿轮产生转矩,力臂是拧扣大齿轮的节园半径,因此转矩测量误差仅与仪表精度有关.齿轮齿条式主钳实现了转矩的实时测量和控制,测量精度高.

  20. Measurement and Modeling of Site-specific Nitrogen and Oxygen Isotopic Composition of Atmospheric Nitrous Oxide at Mace Head, Ireland

    Science.gov (United States)

    McClellan, M. J.; Saikawa, E.; Prinn, R. G.; Ono, S.

    2015-12-01

    Global mixing ratios of atmospheric nitrous oxide (N2O), a potent greenhouse gas, have increased nearly linearly from the beginning of the modern industrial period to today, with the current global average in excess of 325 ppb. This increase can be largely attributed to anthropogenic activity above the level of N2O emissions from natural biotic sources. The effect of N2O on Earth's climate is twofold: in the troposphere, N2O is radiatively active and chemically inert, while it serves as a reactive source of ozone-destroying nitrogen oxides in the stratosphere. The marked altitudinal divide in its reactivity means that all stages in the N2O life cycle—emission, transport, and destruction—must be examined to understand the overall effect of N2O on Earth's climate. However, the understanding of the total impact of N2O is incomplete, as there remain significant uncertainties in the global budget of this gas. Due to unique isotopic substitutions (15N and 18O) made by different N2O sources and stratospheric chemical reactions, the measurement of N2O isotopic ratios in ambient air can help identify the distribution and magnitude of distinct source types. We present the first year of site-specific nitrogen and oxygen isotopic composition data from the MIT Stheno-tunable infrared direct absorption spectroscopy (TILDAS) instrument at Mace Head, Ireland. Aided by the Stheno preconcentration system, Stheno-TILDAS can achieve measurement precisions of 0.10‰ or greater for all isotopic ratios (δ15N and δ18O) in ambient N2O. We further compare these data to the results from Model for Ozone and Related Tracers version 4 (MOZART-4) simulations, including N2O isotopic fractionation processes and MERRA/GEOS-5 reanalysis meteorological fields. These results will form the basis of future Bayesian inverse modeling simulations that will constrain global N2O source, circulation, and sink dynamics better.

  1. Sensitivity of fNIRS measurement to head motion: an applied use of smartphones in the lab.

    Science.gov (United States)

    Cui, Xu; Baker, Joseph M; Liu, Ning; Reiss, Allan L

    2015-04-30

    Powerful computing capabilities in small, easy to use hand-held devices have made smart technologies such as smartphones and tablets ubiquitous in today's society. The capabilities of these devices provide scientists with many tools that can be used to improve the scientific method. Here, we demonstrate how smartphones may be used to quantify the sensitivity of functional near-infrared spectroscopy (fNIRS) signal to head motion. By attaching a smartphone to participants' heads during the fNIRS scan, we were able to capture data describing the degree of head motion. Our results demonstrate that data recorded from an off-the-shelf smartphone accelerometer may be used to identify correlations between head-movement and fNIRS signal change. Furthermore, our results identify correlations between the magnitudes of head-movement and signal artifact, as well as a relationship between the direction of head movement and the location of the resulting signal noise. These data provide a valuable proof-of-concept for the use of off-the-shelf smart technologies in neuroimaging applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Bayesian estimation of the hydraulic and solute transport properties of a small-scale unsaturated soil column

    Directory of Open Access Journals (Sweden)

    Moreira Paulo H. S.

    2016-03-01

    Full Text Available In this study the hydraulic and solute transport properties of an unsaturated soil were estimated simultaneously from a relatively simple small-scale laboratory column infiltration/outflow experiment. As governing equations we used the Richards equation for variably saturated flow and a physical non-equilibrium dual-porosity type formulation for solute transport. A Bayesian parameter estimation approach was used in which the unknown parameters were estimated with the Markov Chain Monte Carlo (MCMC method through implementation of the Metropolis-Hastings algorithm. Sensitivity coefficients were examined in order to determine the most meaningful measurements for identifying the unknown hydraulic and transport parameters. Results obtained using the measured pressure head and solute concentration data collected during the unsaturated soil column experiment revealed the robustness of the proposed approach.

  3. Predictive Maintenance of Hydraulic Lifts through Lubricating Oil Analysis

    OpenAIRE

    Stamatios S. Kalligeros

    2013-01-01

    This article examines the possibility of measuring lift maintenance through analysis of used hydraulic oil. Hydraulic oils have proved to be a reliable indicator for the maintenance performed on elevators. It has also been proved that the end users or the maintenance personnel do not always conform to the instructions of the elevators’ hydraulic machine manufacturer. Furthermore, by examining the proportion of the metals, an estimation of the corrosion and the wear resistance of the joined mo...

  4. Trend of hydraulic units

    Energy Technology Data Exchange (ETDEWEB)

    Deshimaru, Jun' ichi

    1988-11-01

    The gear, vane and piston pumps occupy a more then 90% share in the hydraulic pumps. Comparatively large pumps are mainly variable delivery piston pumps. The piston pumps are comparatively high in output density (output per unit weight), indicating the hydraulic pump in performance, and tend to become higher and higher in it. Though they are mainly 210 to 350kgf/cm/sup 2/ in rated pressure, some of them come to surpass 400kgf/cm/sup 3/ in it. While the progress in computation also requires the high speed operation, high accuracy and other severe conditions for the hydraulic units, which accordingly and increasingly intensify the requirement for hydraulic oil in abrasion resistibility, oxidation stability and response characteristics. While cavitation comes to easily occur, which considerably and disadvantageously influences hydraulic oil in life through degradation, noise level and respondingness. From now on, the development of high performance oil and study of mechanical structure are important. 19 references, 9 figures, 2 tables.

  5. Minidisk against ring infiltrometer measurements to assess the saturated hydraulic conductivity in Mediterranean vineyards (Vitis vinifera L.) under Tillage and No-Tillage managements

    Science.gov (United States)

    Burguet, Maria; Di Prima, Simone; Prosdocimi, Massimo; Taguas, Encarnación V.; Cerdà, Artemi

    2016-04-01

    Vineyard is one of the main crops in the Mediterranean region and it forms, along with wheat and olive, what it is known as the 'Mediterranean triad'. According to the Food and Agriculture Organization of the United Nations (FAO, 2010), the European Union has 4.5 million hectares of land occupied by vineyards. Out of all, the Mediterranean region has the largest total area of vineyards. France, Italy and Spain together are responsible for 48% of global wine production. In Spain, the total surface occupied by vineyards is 1.048.104 ha (Ministry of Agriculture, Food and Environment, 2009), which is translated in a 13% of world total (Wine Institute, 2014). In terms of environmental factors, vineyards are a source of sediments and water due to the tillage and the soil compaction, the lack of vegetation cover and the soil organic matter depletion (Novara et al., 2011; Lieskovsky' et al., 2014; Rodrigo Comino et al., 2015). The infiltration capacity of soils is a key component of the hydrological cycle that can control the non-sustainable rates of runoff and erosion (Cerdà, 1997,1999). In this way research focused on the soil hydrological properties will bring knowledge on how to control the high erosion rates (Cammeraat et al., 2010). Saturated hydraulic conductivity, ks, is the most determining physical parameter in terms of quantifying the components of the global water balance as it interferes in all those processes which are related with water and solute movement and transport through the soil. ks values are required for an adequate modelling of the infiltration and runoff generation processes. However, it is a variable with high variability when it comes to agricultural soils due to different soil managements and the fact that the soil is not a continuous media (Polo et al., 2003). For instance, Leonard and Andrieux (1998) reported in a study done in untilled vineyards in France high differences in infiltration rates through the use of rainfall simulations, which

  6. Variation in reach-scale hydraulic conductivity of streambeds

    Science.gov (United States)

    Stewardson, M. J.; Datry, T.; Lamouroux, N.; Pella, H.; Thommeret, N.; Valette, L.; Grant, S. B.

    2016-04-01

    Streambed hydraulic conductivity is an important control on flow within the hyporheic zone, affecting hydrological, ecological, and biogeochemical processes essential to river ecosystem function. Despite many published field measurements, few empirical studies examine the drivers of spatial and temporal variations in streambed hydraulic conductivity. Reach-averaged hydraulic conductivity estimated for 119 surveys in 83 stream reaches across continental France, even of coarse bed streams, are shown to be characteristic of sand and finer sediments. This supports a model where processes leading to the accumulation of finer sediments within streambeds largely control hydraulic conductivity rather than the size of the coarse bed sediment fraction. After describing a conceptual model of relevant processes, we fit an empirical model relating hydraulic conductivity to candidate geomorphic and hydraulic drivers. The fitted model explains 72% of the deviance in hydraulic conductivity (and 30% using an external cross-validation). Reach hydraulic conductivity increases with the amplitude of bedforms within the reach, the bankfull channel width-depth ratio, stream power and upstream catchment erodibility but reduces with time since the last streambed disturbance. The correlation between hydraulic conductivity and time since a streambed mobilisation event is likely a consequence of clogging processes. Streams with a predominantly suspended load and less frequent streambed disturbances are expected to have a lower streambed hydraulic conductivity and reduced hyporheic fluxes. This study suggests a close link between streambed sediment transport dynamics and connectivity between surface water and the hyporheic zone.

  7. A Space weather information service based upon remote and in-situ measurements of coronal mass ejections heading for Earth

    Directory of Open Access Journals (Sweden)

    Ritter Birgit

    2015-01-01

    Full Text Available The Earth’s magnetosphere is formed as a consequence of interaction between the planet’s magnetic field and the solar wind, a continuous plasma stream from the Sun. A number of different solar wind phenomena have been studied over the past 40 years with the intention of understanding and forecasting solar behavior. One of these phenomena in particular, Earth-bound interplanetary coronal mass ejections (CMEs, can significantly disturb the Earth’s magnetosphere for a short time and cause geomagnetic storms. This publication presents a mission concept consisting of six spacecraft that are equally spaced in a heliocentric orbit at 0.72 AU. These spacecraft will monitor the plasma properties, the magnetic field’s orientation and magnitude, and the 3D-propagation trajectory of CMEs heading for Earth. The primary objective of this mission is to increase space weather forecasting time by means of a near real-time information service, that is based upon in-situ and remote measurements of the aforementioned CME properties. The obtained data can additionally be used for updating scientific models. This update is the mission’s secondary objective. In-situ measurements are performed using a Solar Wind Analyzer instrumentation package and fluxgate magnetometers, while for remote measurements coronagraphs are employed. The proposed instruments originate from other space missions with the intention to reduce mission costs and to streamline the mission design process. Communication with the six identical spacecraft is realized via a deep space network consisting of six ground stations. They provide an information service that is in uninterrupted contact with the spacecraft, allowing for continuous space weather monitoring. A dedicated data processing center will handle all the data, and then forward the processed data to the SSA Space Weather Coordination Center which will, in turn, inform the general public through a space weather forecast. The data

  8. Laboratory evaporation experiments in undisturbed peat columns for determining peat soil hydraulic properties

    Science.gov (United States)

    Dettmann, U.; Frahm, E.; Bechtold, M.

    2013-12-01

    Knowledge about hydraulic properties of organic soils is crucial for the interpretation of the hydrological situation in peatlands. This in turn is the basis for designing optimal rewetting strategies, for assessing the current and future climatic water balance and for quantifying greenhouse gas emissions of CO2, CH4 and N2O, which are strongly controlled by the depth of the peat water table. In contrast to mineral soils, the hydraulic properties of organic soils differ in several aspects. Due to the high amount of organic components, strong heterogeneity, and shrinkage and swelling of peat, accompanied by changing soil volume and bulk density, the applicability of standard hydraulic functions developed for mineral soils for describing peat soil moisture dynamics is often questioned. Hence, the objective of this study was to investigate the applicability of the commonly applied van Genuchten-Mualem (VGM) parameterization and to evaluate model errors for various peat types. Laboratory column experiments with undisturbed peat soils (diameter: 30 cm, height: 20 cm) from 5 different peatlands in Germany were conducted. In numerical simulations using HYDRUS-1D the experimental data were used for an inverse estimation of the soil hydraulic parameters. Using the VGM parameterization, the model errors between observed and measured pressure heads were quantified with a root mean square error (RMSE) of 20 - 65 cm. The RMSE increased for soils with higher organic carbon content and higher porosity. Optimizing the VGM 'tortuosity' parameter (τ) instead of fixing it to its default of 0.5 strongly reduced the RMSE, especially for the soils that showed high pressure head gradients during the experiment. Due to the fact, that very negative pressure heads in peatlands occur rarely, we reduced the range of pressured heads in the inversion to a 'field-relevant' range from 0 to -200 cm which strongly reduced the RMSE to 6 - 12 cm and makes the VGM parameterization applicable for all

  9. Microbial effect on soil hydraulic properties

    Science.gov (United States)

    Furman, Alex; Rosenzweig, Ravid; Volk, Elazar; Rosenkranz, Hella; Iden, Sascha; Durner, Wolfgang

    2014-05-01

    Although largely ignored, the soil contains large amount of biofilms (attached microbes) that can affect many processes. While biochemical processes are studied, biophysical processes receive only little attention. Biofilms may occupy some of the pore space, and by that affect the soil hydraulic properties. This effect on unsaturated soils, however, was not intensively studied. In this research we directly measure the hydraulic properties, namely the soil's unsaturated hydraulic conductivity function and retention curve, for soils containing real biofilm. To do that we inoculate soil with biofilm-forming bacteria and incubate it with sufficient amounts of nutrient until biofilm is formed. The hydraulic properties of the incubated soil are then measured using several techniques, including multi-step outflow and evaporation method. The longer measurements (evaporation method) are conducted under refrigeration conditions to minimize microbial activity during the experiment. The results show a clear effect of the biofilm, where the biofilm-affected soil (sandy loam in our case) behaves like a much finer soil. This qualitatively makes sense as the biofilm generates an effective pore size distribution that is characterized by smaller pores. However, the effect is much more complex and needs to be studied carefully considering (for example) dual porosity models. We compare our preliminary results with other experiments, including flow-through column experiments and experiments with biofilm analogues. Clearly a better understanding of the way microbial activity alters the hydraulic properties may help designing more efficient bioremediation, irrigation, and other soil-related processes.

  10. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  11. 管端加厚液压机振动分析及消除措施%Vibration Analysis and Eliminating Measures of Pipe End Thickening Hydraulic Press

    Institute of Scientific and Technical Information of China (English)

    王秀鑫; 刘志奇; 张军丽; 丁浩伦

    2015-01-01

    This paper describes the oil drill pipe hydraulic which for the processing of oil drill pipe ends. For this hydraulic machine with the poor stable performance, commutation unloading big shock and vibration problems that caused by the large inertia movement, the high pres-sure and large flow. Through in-depth analysis of its system working principle and working vibration phenomena, found that the filling valve not fully discharge pressure and inadequate relief delay, causing the main reason for vibration impact and poor performance stability. Finally, a reasonable and effective technical solutions to address the impact of the hydraulic cylinder vibration generated when the relief return, im-prove performance and stability of its work.%该文介绍了用于石油钻杆加工的管端加厚液压机.针对该液压机流量大、压力高和运动惯量大所造成的稳定性能差、换向卸荷振动冲击大等问题,通过对其系统原理与工作振动现象进行深入的分析,发现充液阀无法充分卸压和卸压延时不足是其产生振动冲击、造成稳定性能差的主要原因;最后提出了合理有效的技术方案,解决了该液压机油缸卸压回程时产生的振动冲击,提高了其工作时稳定性能.

  12. Review of Hydraulic Fracturing for Preconditioning in Cave Mining

    Science.gov (United States)

    He, Q.; Suorineni, F. T.; Oh, J.

    2016-12-01

    Hydraulic fracturing has been used in cave mining for preconditioning the orebody following its successful application in the oil and gas industries. In this paper, the state of the art of hydraulic fracturing as a preconditioning method in cave mining is presented. Procedures are provided on how to implement prescribed hydraulic fracturing by which effective preconditioning can be realized in any in situ stress condition. Preconditioning is effective in cave mining when an additional fracture set is introduced into the rock mass. Previous studies on cave mining hydraulic fracturing focused on field applications, hydraulic fracture growth measurement and the interaction between hydraulic fractures and natural fractures. The review in this paper reveals that the orientation of the current cave mining hydraulic fractures is dictated by and is perpendicular to the minimum in situ stress orientation. In some geotechnical conditions, these orientation-uncontrollable hydraulic fractures have limited preconditioning efficiency because they do not necessarily result in reduced fragmentation sizes and a blocky orebody through the introduction of an additional fracture set. This implies that if the minimum in situ stress orientation is vertical and favors the creation of horizontal hydraulic fractures, in a rock mass that is already dominated by horizontal joints, no additional fracture set is added to that rock mass to increase its blockiness to enable it cave. Therefore, two approaches that have the potential to create orientation-controllable hydraulic fractures in cave mining with the potential to introduce additional fracture set as desired are proposed to fill this gap. These approaches take advantage of directional hydraulic fracturing and the stress shadow effect, which can re-orientate the hydraulic fracture propagation trajectory against its theoretical predicted direction. Proppants are suggested to be introduced into the cave mining industry to enhance the

  13. Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

    2012-01-10

    In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

  14. Soil hydraulic properties near saturation, an improved conductivity model

    DEFF Research Database (Denmark)

    Børgesen, Christen Duus; Jacobsen, Ole Hørbye; Hansen, Søren;

    2006-01-01

    The hydraulic properties near saturation can change dramatically due to the presence of macropores that are usually difficult to handle in traditional pore size models. The purpose of this study is to establish a data set on hydraulic conductivity near saturation, test the predictive capability...... of commonly used hydraulic conductivity models and give suggestions for improved models. Water retention and near saturated and saturated hydraulic conductivity were measured for a variety of 81 top and subsoils. The hydraulic conductivity models by van Genuchten [van Genuchten, 1980. A closed-form equation...... for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44, 892–898.] (vGM) and Brooks and Corey, modified by Jarvis [Jarvis, 1991. MACRO—A Model of Water Movement and Solute Transport in Macroporous Soils. Swedish University of Agricultural Sciences. Department of Soil Sciences...

  15. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew

    2006-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  16. Popeye Project: Hydraulic umbilical

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, K.G.; Williams, V.T.

    1996-12-31

    For the Popeye Project, the longest super-duplex hydraulic umbilical in the world was installed in the Gulf of Mexico. This paper reports on its selection and project implementation. Material selection addresses corrosion in seawater, water-based hydraulic fluid, and methanol. Five alternatives were considered: (1) carbon-steel with traditional coating and anodes, (2) carbon-steel coated with thermally sprayed aluminum, (3) carbon-steel sheathed in aluminum, (4) super-duplex, and (5) titanium. The merits and risks associated with each alternative are discussed. The manufacture and installation of the selected umbilical are also reported.

  17. Issues Related To Troubleshooting Of Avionic Hydraulic Units

    Directory of Open Access Journals (Sweden)

    Jastrzębski Grzegorz

    2014-12-01

    Full Text Available The paper outlines workflows associated with troubleshooting of avionic hydraulic systems with detailed description of the troubleshooting algorithm and classification of diagnostic signals provided by avionic hydraulic systems and their subassemblies. Attention is paid to measurement sequences for diagnostic signals from hydraulic systems, circuits and units. Detailed description is dedicated to an innovative design of a troubleshooting device intended for direct measurements of internal leaks from avionic hydraulic units. Advantages of the proposed measurement method are summarized with benefits from use of the presented device and compared against the methods that are currently in use. Subsequent phases of the troubleshooting process are described with examples of measurement results that have been acquired from subassemblies of hydraulic systems of SU-22 aircrafts currently in service at Polish Air Forces with consideration given to cases when the permissible threshold of diagnostic signals were exceeded. Finally, all results from investigations are subjected to thorough analysis.

  18. Predictive Maintenance of Hydraulic Lifts through Lubricating Oil Analysis

    Directory of Open Access Journals (Sweden)

    Stamatios S. Kalligeros

    2013-12-01

    Full Text Available This article examines the possibility of measuring lift maintenance through analysis of used hydraulic oil. Hydraulic oils have proved to be a reliable indicator for the maintenance performed on elevators. It has also been proved that the end users or the maintenance personnel do not always conform to the instructions of the elevators’ hydraulic machine manufacturer. Furthermore, by examining the proportion of the metals, an estimation of the corrosion and the wear resistance of the joined moving parts can be observed. Additionally, the presence of chlorine and calcium in hydraulic oils demonstrates their function in a highly corrosive environment.

  19. Hydraulic Arm Modeling via Matlab SimHydraulics

    OpenAIRE

    Věchet, Stanislav; Krejsa, Jiří

    2009-01-01

    System modeling is a vital tool for cost reduction and design process speed up in most engineering fields. The paper is focused on modeling of hydraulic arm as a part of intelligent prosthesis project, in the form of 2DOF open kinematic chain. The arm model combines mechanical, hydraulic and electric subsystems and uses Matlab as modeling tool. SimMechanics Matlab extension is used for mechanical part modeling, SimHydraulics toolbox is used for modeling of hydraulic circuit used for actuating...

  20. An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump

    Science.gov (United States)

    Lindley, B. K.; Martinson, A. R.

    1971-01-01

    The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

  1. Measurement of multi-directional azimuth and tilt angles using an improved DVD pickup head with a CMOS sensor: A simulation design study

    Science.gov (United States)

    Sun, Wen-Shing; Lin, Yan-Nan; Tien, Chuen-Lin; Chang, Jenq-Yang

    2013-06-01

    We present a new detection method for an improved DVD pickup head system capable of measuring the multidirectional azimuth and small tilt angles. A complementary metal-oxide semiconductor (CMOS) sensor is used to capture images and analyze the slight shift of the central position of the beam shape when the test plane rotates to create a tilt angle and angular signal. The proposed detection method can determine the azimuth angle of the test plane from 0° to 360° at intervals of 5°. The tilt angle measurement is varied from 0° to 4.2° at intervals of 0.3°. The simulation results show that the improved DVD pickup head system can recognize multi-directional azimuth angles of the test plane under a small tilt.

  2. Soil Structure and Saturated Hydraulic Conductivity

    Science.gov (United States)

    Houskova, B.; Nagy, V.

    The role of soil structure on saturated hydraulic conductivity changes is studied in plough layers of texturally different soils. Three localities in western part of Slovakia in Zitny ostrov (Corn Island) were under investigation: locality Kalinkovo with light Calcaric Fluvisol (FAO 1970), Macov with medium heavy Calcari-mollic Fluvisol and Jurova with heavy Calcari-mollic Fluvisol. Soil structure was determined in dry as well as wet state and in size of macro and micro aggregates. Saturated hydraulic conductivity was measured by the help of double ring method. During the period of ring filling the soil surface was protected against aggregates damage by falling water drops. Spatial and temporal variability of studied parameters was evaluated. Cultivated crops were ensilage maize at medium heavy and heavy soil and colza at light soil. Textural composition of soil and actual water content at the beginning of measurement are one of major factor affecting aggregate stability and consequently also saturated hydraulic conductivity.

  3. HYDRAULICS, TUSCARAWAS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic procedures for estimating flood discharges for a flood insurance...

  4. Hydraulic hoist-press

    Energy Technology Data Exchange (ETDEWEB)

    Babayev, Z.B.; Abashev, Z.V.

    1982-01-01

    The efficiency expert of the Angrenskiy production-technological administration of the production association Sredazugol A. V. Bubnov has suggested a hydraulic hoist-press for repairing road equipment which is a device consisting of lifting mechanism, press and test stand for verifying the high pressure hoses and pumps.

  5. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  6. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on-going...

  7. Effects of model layer simplification using composite hydraulic properties

    Science.gov (United States)

    Sepulveda, Nicasio; Kuniansky, Eve L.

    2010-01-01

    The effects of simplifying hydraulic property layering within an unconfined aquifer and the underlying confining unit were assessed. The hydraulic properties of lithologic units within the unconfined aquifer and confining unit were computed by analyzing the aquifer-test data using radial, axisymmetric two-dimensional (2D) flow. Time-varying recharge to the unconfined aquifer and pumping from the confined Upper Floridan aquifer (USA) were simulated using 3D flow. Conceptual flow models were developed by gradually reducing the number of lithologic units in the unconfined aquifer and confining unit by calculating composite hydraulic properties for the simplified lithologic units. Composite hydraulic properties were calculated using either thickness-weighted averages or inverse modeling using regression-based parameter estimation. No significant residuals were simulated when all lithologic units comprising the unconfined aquifer were simulated as one layer. The largest residuals occurred when the unconfined aquifer and confining unit were aggregated into a single layer (quasi-3D), with residuals over 100% for the leakage rates to the confined aquifer and the heads in the confining unit. Residuals increased with contrasts in vertical hydraulic conductivity between the unconfined aquifer and confining unit. Residuals increased when the constant-head boundary at the bottom of the Upper Floridan aquifer was replaced with a no-flow boundary.

  8. Application of Ferrography to Fault Diagnosis of Hydraulic Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper deals with research on the successful use of ferrography as a wear measurement method for condition monitoring and fault diagnosis of hydraulic systems.The analysis program and progression is discussed, and a case study for condition monitoring and fault diagnosis of hydraulic systems by means of ferrography is also reviewed.

  9. Application of Large-Scale Inversion Algorithms to Hydraulic Tomography in an Alluvial Aquifer.

    Science.gov (United States)

    Fischer, P; Jardani, A; Soueid Ahmed, A; Abbas, M; Wang, X; Jourde, H; Lecoq, N

    2017-03-01

    Large-scale inversion methods have been recently developed and permitted now to considerably reduce the computation time and memory needed for inversions of models with a large amount of parameters and data. In this work, we have applied a deterministic geostatistical inversion algorithm to a hydraulic tomography investigation conducted in an experimental field site situated within an alluvial aquifer in Southern France. This application aims to achieve a 2-D large-scale modeling of the spatial transmissivity distribution of the site. The inversion algorithm uses a quasi-Newton iterative process based on a Bayesian approach. We compared the results obtained by using three different methodologies for sensitivity analysis: an adjoint-state method, a finite-difference method, and a principal component geostatistical approach (PCGA). The PCGA is a large-scale adapted method which was developed for inversions with a large number of parameters by using an approximation of the covariance matrix, and by avoiding the calculation of the full Jacobian sensitivity matrix. We reconstructed high-resolution transmissivity fields (composed of up to 25,600 cells) which generated good correlations between the measured and computed hydraulic heads. In particular, we show that, by combining the PCGA inversion method and the hydraulic tomography method, we are able to substantially reduce the computation time of the inversions, while still producing high-quality inversion results as those obtained from the other sensitivity analysis methodologies.

  10. Hygrometric measurement for on-line monitoring of PWR vessel head penetrations; Detection de fuites de traversees de couvercles de cuve par surveillance hygrometrique

    Energy Technology Data Exchange (ETDEWEB)

    Germain, J.L.; Loisy, F.; Apolzan, S.

    1994-06-01

    In September 1991, a small leak was found on one of the reactor`s upper vessel head penetrations. After inspection, other non-throughwall cracks were localized in the lower part of the vessel head adapter in questions. The same type of crack was later found inside some adapters on other French PWR units. After repairs, the safety authorities granted approval to continue unit operation, with the specific provision that a system for ongoing monitoring of the penetrations be set up. Two types of system were selected to detect leaks through any potential cracks: the first is based on nitrogen-13 detection and the second on steam detection. Both systems call for sampling the air in a confined space above the vessel head. The number and distribution of sampling taps in the circuit, and the balancing of their respective flow rates, are factors in proper monitoring of all vessel head penetrations. Gas-injection holes are also installed in the confined space. These holes are used during the sampling system qualification tests to simulate leaks in various positions and calculate the effective performance of the sampling system. Leaks are simulated using a helium-base gas tracer and measuring tracer concentrations in the sampling system. The system for measuring steam levels in air samples uses chilled-mirror hygrometers. A microcomputer takes regular readings, drives the various automatic functions of the measurement system and automatically analyses the readings so as to monitor operations and trigger an alarm at the first sign of a leak. This system has now been installed for a year and a half on three French PWR units and is functioning satisfactorily. (authors). 5 figs.

  11. Measurement of leaf hydraulic conductance and stomatal conductance and their responses to irradiance and dehydration using the Evaporative Flux Method (EFM).

    Science.gov (United States)

    Sack, Lawren; Scoffoni, Christine

    2012-12-31

    Water is a key resource, and the plant water transport system sets limits on maximum growth and drought tolerance. When plants open their stomata to achieve a high stomatal conductance (gs) to capture CO2 for photosynthesis, water is lost by transpiration(1,2). Water evaporating from the airspaces is replaced from cell walls, in turn drawing water from the xylem of leaf veins, in turn drawing from xylem in the stems and roots. As water is pulled through the system, it experiences hydraulic resistance, creating tension throughout the system and a low leaf water potential (Ψ(leaf)). The leaf itself is a critical bottleneck in the whole plant system, accounting for on average 30% of the plant hydraulic resistance(3). Leaf hydraulic conductance (K(leaf) = 1/ leaf hydraulic resistance) is the ratio of the water flow rate to the water potential gradient across the leaf, and summarizes the behavior of a complex system: water moves through the petiole and through several orders of veins, exits into the bundle sheath and passes through or around mesophyll cells before evaporating into the airspace and being transpired from the stomata. K(leaf) is of strong interest as an important physiological trait to compare species, quantifying the effectiveness of the leaf structure and physiology for water transport, and a key variable to investigate for its relationship to variation in structure (e.g., in leaf venation architecture) and its impacts on photosynthetic gas exchange. Further, K(leaf) responds strongly to the internal and external leaf environment(3). K(leaf) can increase dramatically with irradiance apparently due to changes in the expression and activation of aquaporins, the proteins involved in water transport through membranes(4), and K(leaf) declines strongly during drought, due to cavitation and/or collapse of xylem conduits, and/or loss of permeability in the extra-xylem tissues due to mesophyll and bundle sheath cell shrinkage or aquaporin deactivation(5

  12. Effects of substrate properties on the hydraulic and thermal behavior of a green roof

    Science.gov (United States)

    Sandoval, V. P.; Suarez, F. I.; Victorero, F.; Bonilla, C.; Gironas, J. A.; Vera, S.; Bustamante, W.; Rojas, V.; Pasten, P.

    2014-12-01

    Green roofs are a sustainable urban development solution that incorporates a growing media (also known as substrate) and vegetation into infrastructures to reach additional benefits such as the reduction of: rooftop runoff peak flows, roof surface temperatures, energy utilized for cooling/heating buildings, and the heat island effect. The substrate is a key component of the green roof that allows achieving these benefits. It is an artificial soil that has an improved behavior compared to natural soils, facilitating vegetation growth, water storage and typically with smaller densities to reduce the loads over the structures. Therefore, it is important to study the effects of substrate properties on green roof performance. The objective of this study is to investigate the physical properties of four substrates designed to improve the behavior of a green roof, and to study their impact on the efficiency of a green roof. The substrates that were investigated are: organic soil; crushed bricks; a mixture of mineral soil with perlite; and a mixture of crushed bricks and organic soil. The thermal properties (thermal conductivity, volumetric heat capacity and thermal diffusivity) were measured using a dual needle probe (Decagon Devices, Inc.) at different saturation levels, and the hydraulic properties were measured with a constant head permeameter (hydraulic conductivity) and a pressure plate extractor (water retention curve). This characterization, combined with numerical models, allows understanding the effect of these properties on the hydraulic and thermal behavior of a green roof. Results show that substrates composed by crushed bricks improve the thermal insulation of infrastructures and at the same time, retain more water in their pores. Simulation results also show that the hydraulic and thermal behavior of a green roof strongly depends on the moisture content prior to a rainstorm.

  13. The influence of frontal sinus in brain activation measurements by near-infrared spectroscopy analyzed by realistic head models

    Science.gov (United States)

    Kurihara, Kazuki; Kawaguchi, Hiroshi; Obata, Takayuki; Ito, Hiroshi; Sakatani, Kaoru; Okada, Eiji

    2012-01-01

    Adequate modeling of light propagation in the head is important to predict the sensitivity of NIRS signal and the spatial sensitivity profile of source-detector pairs. The 3D realistic head models of which the geometry is based upon the anatomical images acquired by magnetic resonance imaging and x-ray computed tomography are constructed to investigate the influence of the frontal sinus on the NIRS signal and spatial sensitivity. Light propagation in the head is strongly affected by the presence of the frontal sinus. The light tends to propagate around the frontal sinus. The influence of the frontal sinus on the sensitivity of the NIRS signal to the brain activation is not consistent and depends on the depth of the frontal sinus, the optical properties of the superficial tissues and the relative position between the source-detector pair and the frontal sinus. The frontal sinus located in the shallow region of the skull tends to reduce the sensitivity of the NIRS signal while the deep frontal sinus can increase the sensitivity of the NIRS signal. PMID:23024906

  14. Online Measurement of Effective Bulk Modulus in Hydraulic System by the Soft-sensing Model%液压系统油液有效体积模量的在线软测量

    Institute of Scientific and Technical Information of China (English)

    闫小乐; 谷立臣

    2011-01-01

    Effective bulk modulus of hydraulic oil is an important factor of dynamic characters in a hydraulic control system and it's regarded as one of the essential parameter for monitoring the condition of the sets at real operation.Based on transient flow theory and gas-liquid two-phase flow theory, a novel soft-sensing model is suggested for the online measurement of the effective bulk modulus and numerical simulations of the model are carried out.The model represents the relationship among natural frequency,pressure, bubble volume fraction and effective bulk modulus of oil in a straight pipe.The key problem of using this model in practice is how to measure the natural fiequency online.The feasible solution is installing piezoelectricity type pressure sensors at two oil pressure fluctuation monitoring points selected in the hydraulic power system, and through online excitation, the oil pressure frequency response function is dynamically measured, thus the natural frequency of oil is identified.Moreover, the effective bulk modulus may be estimated by the above model.This model is tested on the experiment platform of multi-source information acquisition of the hydraulic system.The results indicate that the model can be used successfully in the online measurement of the effective bulk modulus of hydraulic oil.%液压油的有效体积模量不仅是影响液压控制系统性能的重要参数,也是反映液压设备运行状态的特征参数.以液压油有效体积模量的在线监测为研究目的,利用瞬变流理论和气液两相流理论,在频域内建立液压系统管路中油液的固有频率、压力、气泡体积分数与有效体积模量关系的软测量模型,并对其进行数值仿真分析.该模型应用的关键问题是如何在线测量油液的同有频率,可行的解决方案是在液压动力系统选定的两个油液压力波动监测点安装压电式压力传感器,通过在线激励动态测量油液的压力频率响应函数,从

  15. Simulation of a Hydraulic Pump Control Valve

    Science.gov (United States)

    Molen, G. Vander; Akers, A.

    1987-01-01

    This paper describes the mode of operation of a control valve assembly that is used with a hydraulic pump. The operating system of the valve is modelled in a simplified form, and an analogy for hydraulic resonance of the pressure sensing system is presented. For the control valve investigated, air entrainment, length and diameter of the resonator neck, and valve mass produced the greatest shift in resonant frequency. Experimental work was conducted on the hydraulic system so that the resonance levels and frequencies could be measured and the accuracy of the theory verified. The results obtained make it possible to evaluate what changes to any of the variables considered would be most effective in driving the second harmonic frequency above the operating range.

  16. Inferring the heterogeneity, transmissivity and hydraulic conductivity of crystalline aquifers from a detailed water-table map

    Science.gov (United States)

    Dewandel, Benoît; Jeanpert, Julie; Ladouche, Bernard; Join, Jean-Lambert; Maréchal, Jean-Christophe

    2017-07-01

    Estimating the transmissivity or hydraulic conductivity field to characterize the heterogeneity of a crystalline aquifer is particularly difficult because of the wide variations of the parameters. We developed a new approach based on the analysis of a dense network of water-table data. It is based on the concept that large-scale variations in hydraulic head may give information on large-scale aquifer parameters. The method assumes that flux into the aquifer is mainly sub-horizontal and that the water table is mostly controlled by topography, rather than recharge. It is based on an empirical statistical relationship between field data on transmissivity and the inverse slope values of a topography-reduced water-table map. This relationship is used to compute a transmissivity map that must be validated with field measurements. The proposed approach can provide a general pattern of transmissivity, or hydraulic conductivity, but cannot correctly reproduce strong variations at very local scale (less than10 m), and will face of some uncertainties where vertical flows cannot be neglected. The method was tested on a peridotite (ultramafic rock) aquifer of 3.5 km2 in area located in New Caledonia. The resulting map shows transmissivity variations over about 5 orders of magnitude (average LogT: -5.2 ± 0.7). Comparison with a map based on measured water-level data (n = 475) shows that the comparison between LogT-computed values and LogT data deduced from 28 hydraulic tests is estimated with an error less than 20% in 71% of cases (LogT ± 0.4), and with an error less than 10% (LogT ± 0.2 on average) in 39% of cases. From this map a hydraulic-conductivity map has been computed showing values ranging over 8 orders of magnitude. The repeatability of the approach was tested on a second data set of hydraulic-head measurements (n = 543); the mean deviation between both LogT maps is about 11%. These encouraging results show that the method can give valuable parameter estimates, and

  17. HYDRAULIC CONDUCTIVITY OF THREE GEOSYNTHETIC CLAY LINERS

    Science.gov (United States)

    The hydraulic conductivity of three 2.9 m2 (32 sq ft) geosynthetic clay liners (GCLs) was measured. Tests were performed on individual sheets of the GCLs, on overlapped pieces of GCLs, and on composite liners consisting of a punctured geomembrane overlying a GCL. Hyd...

  18. Dentin permeability: determinants of hydraulic conductance.

    Science.gov (United States)

    Reeder, O W; Walton, R E; Livingston, M J; Pashley, D H

    1978-02-01

    A technique is described which permits measurements of the ease with which fluid permeates dentin. This value, the hydraulic conductance of dentin, increased as surface area increases and/or as dentin thickness decreases. It increased 32-fold when dentin was acid etched due to removal of surface debris occluding the tubules.

  19. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  20. EXPERIMENTAL INVESTIGATION OF CHARACTERISTIC FREQUENCY IN UNSTEADY HYDRAULIC BEHAVIOUR OF A LARGE HYDRAULIC TURBINE

    Institute of Scientific and Technical Information of China (English)

    WANG Fu-jun; LI Xiao-qin; MA Jia-mei; YANG Min; ZHU Yu-liang

    2009-01-01

    The features of unsteady flow such as pressure variation and fluctuation in a large hydraulic turbine usually lead to the instability of operation.This article reports the recent in site investigation concerning the characteristic frequencies in pressure fluctuation,shaft torsional oscillation and structural vibration of a prototype 700 MW Francis turbine unit.The investigation was carried out for a wide load range of 200 MW-700 MW in the condition of water head 57 m-90 m.An extensive analysis of both time-history and frequency data of these unsteady hydraulic behaviours was conducted.It was observed that the pressure fluctuation in a draft tube is stronger than that in upstream flow passage.The low frequency with about one third of rotation frequency is dominative for the pressure fluctuation in part load range.Also the unsteady features of vibration of head cover and torsional oscillation of shaft exhibited the similar features.Numerical analysis showed that the vibration and oscillation are caused by vortex rope in the draft tube.In addition,a strong vibration with special characteristic frequency was observed for the head cover in middle load range.The pressure fluctuation in the draft tube with the same frequency was also recorded.Because this special vibration has appeared in the designed normal running condition,it should be avoided by carefully allocating power load in the future operation.

  1. Remotely Adjustable Hydraulic Pump

    Science.gov (United States)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  2. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  3. DLC coatings for hydraulic applications

    Institute of Scientific and Technical Information of China (English)

    Luca NOBILI; Luca MAGAGNIN

    2009-01-01

    Replacement of lubricating oils with water or low-viscosity fluids is highly desirable in many industrial fields, on account of the environmental and economical advantages. Low lubricity of water might be insufficient for proper operation of hydraulic components, and diamond-like carbon(DLC) coatings are very attractive as solid lubricant films. A remote-plasma PACVD process was utilized to deposit hydrogenated DLC coatings (a-C:H) on different substrates. Microindentation measurements show that the coating hardness is around 35 GPa. Tribological behavior was evaluated by block-on-ring tests performed in water and water with alumina. The wear rate was calculated after measuring the wear volume by a laser profilemeter. Morphological and compositional analysis of the wear tracks reveal that coating failure may occur by abrasive wear or delamination, depending on the substrate properties. Hard and smooth substrates give the best results and dispersed alumina particles increase the wear rate.

  4. Head Injuries

    Science.gov (United States)

    ... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...

  5. Head Tilt

    Science.gov (United States)

    ... Healthy Living Healthy Living Healthy Living Nutrition Fitness Sports Oral Health Emotional Wellness Growing Healthy Sleep Safety & ... When this happens, the neck muscles go into spasm, causing the head to tilt to one side. ...

  6. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay Safe: Baseball Concussions Concussions: Getting Better Sports and Concussions Dealing ...

  7. Head MRI

    Science.gov (United States)

    ... heart valves Heart defibrillator or pacemaker Inner ear (cochlear) implants Kidney disease or dialysis (you may not ... to: Abnormal blood vessels in the brain ( arteriovenous malformations of the head ) Tumor of the nerve that ...

  8. A multiscale approach to determine hydraulic conductivity in thick claystone aquitards using field, laboratory, and numerical modeling methods

    Science.gov (United States)

    Smith, L. A.; Barbour, S. L.; Hendry, M. J.; Novakowski, K.; van der Kamp, G.

    2016-07-01

    Characterizing the hydraulic conductivity (K) of aquitards is difficult due to technical and logistical difficulties associated with field-based methods as well as the cost and challenge of collecting representative and competent core samples for laboratory analysis. The objective of this study was to produce a multiscale comparison of vertical and horizontal hydraulic conductivity (Kv and Kh, respectively) of a regionally extensive Cretaceous clay-rich aquitard in southern Saskatchewan. Ten vibrating wire pressure transducers were lowered into place at depths between 25 and 325 m, then the annular was space was filled with a cement-bentonite grout. The in situ Kh was estimated at the location of each transducer by simulating the early-time pore pressure measurements following setting of the grout using a 2-D axisymmetric, finite element, numerical model. Core samples were collected during drilling for conventional laboratory testing for Kv to compare with the transducer-determined in situ Kh. Results highlight the importance of scale and consideration of the presence of possible secondary features (e.g., fractures) in the aquitard. The proximity of the transducers to an active potash mine (˜1 km) where depressurization of an underlying aquifer resulted in drawdown through the aquitard provided a unique opportunity to model the current hydraulic head profile using both the Kh and Kv estimates. Results indicate that the transducer-determined Kh estimates would allow for the development of the current hydraulic head distribution, and that simulating the pore pressure recovery can be used to estimate moderately low in situ Kh (<10-11 m s-1).

  9. Can measurement of cervical length, fetal head position and posterior cervical angle be an alternative method to Bishop score in the prediction of successful labor induction?

    Science.gov (United States)

    Gokturk, Umut; Cavkaytar, Sabri; Danısman, Nuri

    2014-09-10

    Abstract Aim: The purpose of this study was to evaluate sonographic cervical length, posterior cervical angle and fetal head position in predicting successful induction of labor at term can be an alternative method to Bishop score. Methods: This prospective observational study recruited 223 women with singleton gestations scheduled for induction of labor at 37-42 weeks. Parity, body mass index, Bishop score, fetal head position, cervical angle measurement and cervical length was investigated to predict successful labor induction. Multiple regression analysis was performed to determine the parameters in the prediction of successful vaginal delivery within 24 hours. Results: Forty-five patients were excluded because of cesarean section performed for other reasons than arrest of dilation or fetal head descent (43 fetal distress, 2 cord prolapsus). Remaining 178 patients were divided into two groups according to duration of delivery time. 139 patients delivered within 24 hours were classified as group I, 39 patients delivered after 24 hours were classified as group II. Percentage of multiparity was statistically significantly higher in group I than in group II [59 (42.4%), 9 (23.0%) respectively, p = 0.009]. Cervical length was statistically significantly shorter in group I than in group II [23.1 ± 7.42 mm, 31.3 ± 6.83 mm respectively, p Bishop score was statistically significantly higher in group I than in group II [3 (1-4), 1 (1-4) respectively, p Bishop score were statistically significantly predictive in successful labor induction. Conclusion: Multiparity status, cervical length, posterior cervical angle and Bishop score can predict successful labor induction, but fetal head position is not predictive in successful labor induction.

  10. Is high-resolution inverse characterization of heterogeneous river bed hydraulic conductivities needed and possible?

    Directory of Open Access Journals (Sweden)

    W. Kurtz

    2013-10-01

    -resolution characterization of L fields with EnKF is still feasible. For less heterogeneous river bed hydraulic conductivities, a high-resolution characterization of L is less important. When uncertainties in the hydraulic parameters of the aquifer are also regarded in the assimilation, the errors in state and flux predictions increase, but the ensemble with a high spatial resolution for L still outperforms the ensembles with effective L values. We conclude that for strongly heterogeneous river beds the commonly applied simplified representation of the streambed, with spatially homogeneous parameters or constant parameters for a few zones, might yield significant biases in the characterization of the water balance. For strongly heterogeneous river beds, we suggest adopting a stochastic field approach to model the spatially heterogeneous river beds geostatistically. The paper illustrates that EnKF is able to calibrate such heterogeneous streambeds on the basis of hydraulic head measurements, outperforming zonation approaches.

  11. Measurement of Sedimentary Interbed Hydraulic Properties and Their Hydrologic Influence near the Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory

    Science.gov (United States)

    Perkins, Kim S.

    2003-01-01

    Disposal of wastewater to unlined infiltration ponds near the Idaho Nuclear Technology and Engineering Center (INTEC), formerly known as the Idaho Chemical Processing Plant, at the Idaho National Engineering and Environmental Laboratory (INEEL) has resulted in the formation of perched water bodies in the unsaturated zone (Cecil and others, 1991). The unsaturated zone at INEEL comprises numerous basalt flows interbedded with thinner layers of coarse- to fine-grained sediments and perched ground-water zones exist at various depths associated with massive basalts, basalt-flow contacts, sedimentary interbeds, and sediment-basalt contacts. Perched ground water is believed to result from large infiltration events such as seasonal flow in the Big Lost River and wastewater discharge to infiltration ponds. Evidence from a large-scale tracer experiment conducted in 1999 near the Radioactive Waste Management Complex (RWMC), approximately 13 km from the INTEC, indicates that rapid lateral flow of perched water in the unsaturated zone may be an important factor in contaminant transport at the INEEL (Nimmo and others, 2002b). Because sedimentary interbeds, and possibly baked-zone alterations at sediment-basalt contacts (Cecil and other, 1991) play an important role in the generation of perched water it is important to assess the hydraulic properties of these units.

  12. Multiobjective Optimization of Effective Soil Hydraulic Properties on a Lysimeter from a Layered, Gravelly Vadose Zone

    Science.gov (United States)

    Werisch, Stefan; Lennartz, Franz

    2013-04-01

    Estimation of effective soil hydraulic parameters for characterization of the vadose zone properties is important for many applications from prediction of solute and pesticide transport to water balance modeling in small catchments. Inverse modeling has become a common approach to infer the parameters of the water retention and hydraulic conductivity functions from dynamic experiments under varying boundary conditions. To gain further inside into to the water transport behavior of an agricultural field site with a layered, gravelly vadose zone, a lysimeter was taken and equipped with a total of 48 sensors (24 tensiometers and 24 water content probes). The sensors were arranged in 6 vertical arrays consisting of 4 sensor pairs, respectively. Pressure heads and water contents were measured in four depths in each of the arrays allowing for the estimation of the soil hydraulic properties of the three individual soil layers by inverse modeling. For each of the soil horizons, a separate objective function was defined to fit the model to the observation. We used the global multiobjective multimethod search algorithm AMALGAM (Vrugt et al., 2007) in combination with the water flow and solute transport model Hydrus1D (Šimúnek et al., 2008) to estimate the soil hydraulic properties of the Mualem van Genuchten model (van Genuchten, 1980). This experimental design served for the investigation of two important questions: a) do effective soil hydraulic properties at the lysimeter scale exist, more specifically: can a single representative parameter set be found which describes the hydraulic behavior in each of the arrays with acceptable performance? And b) which degree of freedom is necessary or required for an accurate description of the one dimensional water flow at each of the arrays? Effective soil hydraulic parameters were obtained for each of the sensor arrays individually, resulting in good agreement between the model predictions and the observations for the individual

  13. Self-potential observations during hydraulic fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Jeffrey R.; Glaser, Steven D.

    2007-09-13

    The self-potential (SP) response during hydraulic fracturing of intact Sierra granite was investigated in the laboratory. Excellent correlation of pressure drop and SP suggests that the SP response is created primarily by electrokinetic coupling. For low pressures, the variation of SP with pressure drop is linear, indicating a constant coupling coefficient (Cc) of -200 mV/MPa. However for pressure drops >2 MPa, the magnitude of the Cc increases by 80% in an exponential trend. This increasing Cc is related to increasing permeability at high pore pressures caused by dilatancy of micro-cracks, and is explained by a decrease in the hydraulic tortuosity. Resistivity measurements reveal a decrease of 2% prior to hydraulic fracturing and a decrease of {approx}35% after fracturing. An asymmetric spatial SP response created by injectate diffusion into dilatant zones is observed prior to hydraulic fracturing, and in most cases this SP variation revealed the impending crack geometry seconds before failure. At rupture, injectate rushes into the new fracture area where the zeta potential is different than in the rock porosity, and an anomalous SP spike is observed. After fracturing, the spatial SP distribution reveals the direction of fracture propagation. Finally, during tensile cracking in a point load device with no water flow, a SP spike is observed that is caused by contact electrification. However, the time constant of this event is much less than that for transients observed during hydraulic fracturing, suggesting that SP created solely from material fracture does not contribute to the SP response during hydraulic fracturing.

  14. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    OpenAIRE

    HUANG, Ye; Liu, Changsheng; Shiongur Bamed

    2014-01-01

    Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under...

  15. HYDRAULIC CHARACTERISTICS OF VERTICAL VORTEX AT HYDRAULIC INTAKES

    Institute of Scientific and Technical Information of China (English)

    CHEN Yun-liang; WU Chao; YE Mao; JU Xiao-ming

    2007-01-01

    The trace of vertical vortex flow at hydraulic intakes is of the shape of spiral lines, which was observed in the presented experiments with the tracer technique. It represents the fluid particles flow spirally from the water surface to the underwater and rotate around the vortex-axis multi-cycle. This process is similar to the movement of screw. To describe the multi-circle spiral characteristics under the axisymmetric condition, the vertical vortex would change not only in the radial direction but also in the axial direction. The improved formulae for three velocity components for the vertical vortex flow were deduced by using the method of separation of variables in this article. In the improved formulae, the velocity components are the functions of the radial and axial coordinates, so the multi-circle spiral flow of vertical vortex could be simulated. The calculated and measured results for the vertical vortex flow were compared and the causes of errors were analyzed.

  16. Preliminary Testing of a Patient-Reported Outcome Measure for Recurrent or Metastatic Head and Neck Cancer.

    Science.gov (United States)

    Jackson, Leanne K; Deng, Jie; Ridner, Sheila H; Gilbert, Jill; Dietrich, Mary S; Murphy, Barbara A

    2016-05-01

    We describe development and preliminary testing of Vanderbilt Head and Neck Symptom Survey-Recurrent/Metastatic (VHNSS-RM) to assess residual symptoms, tumor-related symptoms, and side effects from therapy. Items were identified through patient and provider interviews. Card sort selected high-yield and high-impact items. The VHNSS-RM was administered to 50 patients with recurrent/metastatic head and neck cancer (RMHNC). The VHNSS-RM includes 12 unique symptoms (diet change, tongue movement affecting speech/swallowing, face/neck swelling, neck/jaw cramping, bad breath, drooling, wound drainage/pain/odor, nasal congestion/drainage, eyes watering, face/tongue/ear/scalp numbness, headaches, and confusion) and 7 unique psychosocial issues (burden to family/friends, lost independence, fear, embarrassment, mood swings, stress, and boredom). The VHNSS-RM contains 35 physical and 12 psychosocial issues. The VHNSS-RM is feasible and not overly burdensome. Nineteen unique items may improve palliation to patients with RMHNC. © The Author(s) 2015.

  17. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2014-09-01

    Full Text Available Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under light loads and wearing of the variable-displacement pump. To overcome these shortcomings, this article designs a closed hydraulic control system in which an AC servo motor drives a quantitative pump that controls a spiral swinging hydraulic cylinder, and analyzes and calculates the structure and parameters of a spiral swinging hydraulic cylinder. The hydraulic system adjusts the servo motor’s speed according to the requirements of the control system, and the motor power matches the power provided to components, thus eliminating the throttling loss of hydraulic circuits. The system is compact, produces a large output force, provides stable transmission, has a quick response, and is suitable as a hydraulic control system of a large butterfly valve.

  18. Determining the Porosity and Saturated Hydraulic Conductivity of Binary Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.; Ward, Anderson L.; Keller, Jason M.

    2009-09-27

    Gravels and coarse sands make up significant portions of some environmentally important sediments, while the hydraulic properties of the sediments are typically obtained in the laboratory using only the fine fraction (e.g., <2 mm or 4.75 mm). Researchers have found that the content of gravel has significant impacts on the hydraulic properties of the bulk soils. Laboratory experiments were conducted to measure the porosity and the saturated hydraulic conductivity of binary mixtures with different fractions of coarse and fine components. We proposed a mixing-coefficient model to estimate the porosity and a power-averaging method to determine the effective particle diameter and further to predict the saturated hydraulic conductivity of binary mixtures. The proposed methods could well estimate the porosity and saturated hydraulic conductivity of the binary mixtures for the full range of gravel contents and was successfully applied to two data sets in the literature.

  19. Pedotransfer functions estimating soil hydraulic properties using different soil parameters

    DEFF Research Database (Denmark)

    Børgesen, Christen Duus; Iversen, Bo Vangsø; Jacobsen, Ole Hørbye;

    2008-01-01

    Estimates of soil hydraulic properties using pedotransfer functions (PTF) are useful in many studies such as hydrochemical modelling and soil mapping. The objective of this study was to calibrate and test parametric PTFs that predict soil water retention and unsaturated hydraulic conductivity...... parameters. The PTFs are based on neural networks and the Bootstrap method using different sets of predictors and predict the van Genuchten/Mualem parameters. A Danish soil data set (152 horizons) dominated by sandy and sandy loamy soils was used in the development of PTFs to predict the Mualem hydraulic...... of the hydraulic properties of the studied soils. We found that introducing measured water content as a predictor generally gave lower errors for water retention predictions and higher errors for conductivity predictions. The best of the developed PTFs for predicting hydraulic conductivity was tested against PTFs...

  20. COMPUTATIONAL FLOW RATE FEEDBACK AND CONTROL METHOD IN HYDRAULIC ELEVATORS

    Institute of Scientific and Technical Information of China (English)

    Xu Bing; Ma Jien; Lin Jianjie

    2005-01-01

    The computational flow rate feedback and control method, which can be used in proportional valve controlled hydraulic elevators, is discussed and analyzed. In a hydraulic elevator with this method, microprocessor receives pressure information from the pressure transducers and computes the flow rate through the proportional valve based on pressure-flow conversion real time algorithm. This hydraulic elevator is of lower cost and energy consumption than the conventional closed loop control hydraulic elevator whose flow rate is measured by a flow meter. Experiments are carried out on a test rig which could simulate the load of hydraulic elevator. According to the experiment results, the means to modify the pressure-flow conversion algorithm are pointed out.

  1. Reactive barriers: hydraulic performance and design enhancements.

    Science.gov (United States)

    Painter, B D M

    2004-01-01

    The remediation of contaminated ground water is a multibillion-dollar global industry. Permeable reactive barriers (PRBs) are one of the leading technologies being developed in the search for alternatives to the pump-and-treat method. Improving the hydraulic performance of these PRBs is an important part of maximizing their potential to the industry. Optimization of the hydraulic performance of a PRB can be defined in terms of finding the balance between capture, residence time, and PRB longevity that produces a minimum-cost acceptable design. Three-dimensional particle tracking was used to estimate capture zone and residence time distributions. Volumetric flow analysis was used for estimation of flow distribution across a PRB and in the identification of flow regimes that may affect the permeability or reactivity of portions of the PRB over time. Capture zone measurements extended below the base of partially penetrating PRBs and were measured upgradient from the portion of aquifer influenced by PRB emplacement. Hydraulic performance analysis of standard PRB designs confirmed previously presented research that identified the potential for significant variation in residence time and capture zone. These variations can result in the need to oversize the PRB to ensure that downgradient contaminant concentrations do not exceed imposed standards. The most useful PRB design enhancements for controlling residence time and capture variation were found to be customized downgradient gate faces, velocity equalization walls, deeper emplacement of the funnel than the gate, and careful manipulation of the hydraulic conductivity ratio between the gate and the aquifer.

  2. Hydraulic analysis of cell-network treatment wetlands

    Science.gov (United States)

    Wang, Huaguo; Jawitz, James W.

    2006-11-01

    SummaryWhen individual cells of a multiple-cell treatment wetland are hydraulically connected, the wetland has a cell-network structure. The hydraulic performance of treatment wetlands is often characterized using tracer residence time distributions (RTDs) measured between the wetland inlet and outlet, such that the wetland is considered as a single hydraulic unit, regardless of the extent of networking between individual internal cells. This work extends the single hydraulic unit approach to enable the specification of moments and RTD parameters for individual cells, or clusters of cells, within the cell-network based on inert tracer tests with injection only at the network inlet. Hydraulic performance is quantified in terms of hydraulic efficiency and travel time dimensionless variance using both the method of moments and RTD modeling. Cell-network analysis was applied to a case study from the Orlando Easterly Wetland (OEW), demonstrating the improvement in hydraulic performance of individual wetland cells following wetland restoration activities. Furthermore, cell-network analysis indicated that the location of water quality sampling station locations within the cell network can significantly affect the accuracy of pollutant removal effectiveness estimation when the individual sample station RTD does not represent the hydraulic unit RTD. At the OEW, it was determined that historical nutrient removal effectiveness estimation may be underestimated for one area and overestimated for another, and recommendations were provided for sample station locations to minimize future performance estimation errors.

  3. Efficiency limit factor analysis for the Francis-99 hydraulic turbine

    Science.gov (United States)

    Zeng, Y.; Zhang, L. X.; Guo, J. P.; Guo, Y. K.; Pan, Q. L.; Qian, J.

    2017-01-01

    The energy loss in hydraulic turbine is the most direct factor that affects the efficiency of the hydraulic turbine. Based on the analysis theory of inner energy loss of hydraulic turbine, combining the measurement data of the Francis-99, this paper calculates characteristic parameters of inner energy loss of the hydraulic turbine, and establishes the calculation model of the hydraulic turbine power. Taken the start-up test conditions given by Francis-99 as case, characteristics of the inner energy of the hydraulic turbine in transient and transformation law are researched. Further, analyzing mechanical friction in hydraulic turbine, we think that main ingredients of mechanical friction loss is the rotation friction loss between rotating runner and water body, and defined as the inner mechanical friction loss. The calculation method of the inner mechanical friction loss is given roughly. Our purpose is that explore and research the method and way increasing transformation efficiency of water flow by means of analysis energy losses in hydraulic turbine.

  4. Stem Hydraulic Conductivity depends on the Pressure at Which It Is Measured and How This Dependence Can Be Used to Assess the Tempo of Bubble Pressurization in Recently Cavitated Vessels1[OPEN

    Science.gov (United States)

    Liu, Jinyu; Tyree, Melvin T.

    2015-01-01

    Cavitation of water in xylem vessels followed by embolism formation has been authenticated for more than 40 years. Embolism formation involves the gradual buildup of bubble pressure (air) to atmospheric pressure as demanded by Henry’s law of equilibrium between gaseous and liquid phases. However, the tempo of pressure increase has not been quantified. In this report, we show that the rate of pressurization of embolized vessels is controlled by both fast and slow kinetics, where both tempos are controlled by diffusion but over different spatial scales. The fast tempo involves a localized diffusion from endogenous sources: over a distance of about 0.05 mm from water-filled wood to the nearest embolized vessels; this process, in theory, should take 17 h, with complete equilibrium requiring 1 to 2 d. The implications of these timescales for the standard methods of measuring percentage loss of hydraulic conductivity are discussed in theory and deserve more research in future. PMID:26468516

  5. Effects of Barometric Fluctuations on Well Water-Level Measurements and Aquifer Test Data

    Energy Technology Data Exchange (ETDEWEB)

    FA Spane, Jr.

    1999-12-16

    The Pacific Northwest National Laboratory, as part of the Hanford Groundwater Monitoring Project, examines the potential for offsite migration of contamination within underlying aquifer systems. Well water-level elevation measurements from selected wells within these aquifer systems commonly form the basis for delineating groundwater-flow patterns (i.e., flow direction and hydraulic gradient). In addition, the analysis of water-level responses obtained in wells during hydrologic tests provides estimates of hydraulic properties that are important for evaluating groundwater-flow velocity and transport characteristics. Barometric pressure fluctuations, however, can have a discernible impact on well water-level measurements. These barometric effects may lead to erroneous indications of hydraulic head within the aquifer. Total hydraulic head (i.e., sum of the water-table elevation and the atmospheric pressure at the water-table surface) within the aquifer, not well water-level elevation, is the hydrologic parameter for determining groundwater-flow direction and hydraulic gradient conditions. Temporal variations in barometric pressure may also adversely affect well water-level responses obtained during hydrologic tests. If significant, adjustments or removal of these barometric effects from the test-response record may be required for quantitative hydraulic property determination. This report examines the effects of barometric fluctuations on well water-level measurements and evaluates adjustment and removal methods for determining areal aquifer head conditions and aquifer test analysis. Two examples of Hanford Site unconfined aquifer tests are examined that demonstrate barometric response analysis and illustrate the predictive/removal capabilities of various methods for well water-level and aquifer total head values. Good predictive/removal characteristics were demonstrated with best corrective results provided by multiple-regression deconvolution methods.

  6. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  7. Spinning hydraulic jump

    Science.gov (United States)

    Abderrahmane, Hamid; Kasimov, Aslan

    2013-11-01

    We report an experimental observation of a new symmetry breaking of circular hydraulic jump into a self-organized structure that consists of a spinning polygonal jump and logarithmic-spiral waves of fluid elevation downstream. The waves are strikingly similar to spiral density waves in galaxies. The fluid flow exhibits counterparts of salient morphological features of galactic flows, in particular the outflow from the center, jets, circum-nuclear rings, gas inflows toward the galactic center, and vortices. The hydrodynamic instability revealed here may have a counterpart that plays a role in the formation and sustainability of spiral arms in galaxies.

  8. 46 CFR 28.880 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... hydraulic equipment and the adjacent work area. Protection shall be afforded to the operator of hydraulic... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.880 Section 28.880 Shipping... INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.880 Hydraulic equipment. (a) Each hydraulic system must...

  9. Dynamic effects of wet-dry cycles and crust formation on the saturated hydraulic conductivity of surface soils in the constructed Hühnerwasser ("Chicken Creek") catchment

    Science.gov (United States)

    Hinz, Christoph; Schümberg, Sabine; Kubitz, Anita; Frank, Franzi; Cheng, Zhang; Nanu Frechen, Tobias; Pohle, Ina

    2016-04-01

    Highly disturbed soils and substrates used in land rehabilitation undergo rapid changes after the first wetting events which in turn can lead to ecosystem degradation. Such changes were detected during the early development of the constructed Hühnerwasser ("Chicken Creek") catchment in Lusatia, Germany. Surface substrates consisting of quaternary sandy sediments formed surface seals during the first rainfall events leading to reduced infiltration and substantially increased surface runoff. Subsequently biological soil crusts formed and stabilised the surface. The aim of this study is to investigate the factors that cause the hydraulic conductivity to decrease using undisturbed and disturbed soil samples. Based on the hypothesis that physical and biological crusts lower the hydraulic conductivity, the first set of experiments with undisturbed soil cores from the Hühnerwasser catchment were carried out to measure the saturated hydraulic conductivity using the constant head method. Measurements were done with intact cores and repeated after the surface crust was removed. As the quaternary glacial sediments tend to display hard setting behaviour, we further hypothesised that the mobilisation of fine particles within the cores lead to pore clogging and that wet-dry cycles will therefore decrease hydraulic conductivity. A second set of experiments using the same methodology consisted of five repeated measurements of hydraulic conductivity after each drying cycle. These measurements were done with undisturbed core samples as well as repacked cores in order to assess how dry packing affects the dynamics of the hydraulic conductivity somewhat similar to the situation during the first wetting after completion of the catchment construction. For all experiments, the temporal evolution of hydraulic conductivity was measured and the turbidity of the effluent was recorded. The results clearly demonstrated that the substrate is highly unstable. The first set of experiments

  10. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif

    2014-01-01

    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  11. Study of head anthropometric measurements based on 3-D scanning%基于三维扫描的人体头面部测量方法研究

    Institute of Scientific and Technical Information of China (English)

    吴明磊; 吴壮志; 刘何庆; 刘保钢; 卜伟平; 王兴伟; 苏芳; 王桂友; 李珩

    2015-01-01

    目的 研究建立非接触式三维扫描的人体头面部测量方法,与传统的手工测量结果进行比较,对三维扫描的人体测量方法和结果进行评价. 方法 采用定制的非接触式三维扫描设备,对150名男性飞行员进行头面部扫描,获取人体头面部三维点云模型.同时采用传统手工测量方法测量每名受试者头面部15项人体数据.对扫描模型进行去噪、修补等处理,在三维扫描图像上标注测点,计算测量项目.每个扫描图像上完成23个测点标注和15个测量项目的计算.两种测量方法的测点和测量项目的定义完全一致.采用大样本配对t检验,对两种测量方法的测量结果进行统计学分析. 结果 通过两种测量方法获得了150名受试者头面部15项人体测量数据,统计得到两种测量方法每个测量项目的数据范围(最大值和最小值)、平均值和标准差,以及每个测量项目差值的数据范围、平均值和标准差.其中测量项目差值的平均值<2.0 mm的有5项,2.0~4.0 mm的有4项,>4.0~8.0 mm的有6项.3个测量项目两种测量方法结果差异无统计学意义,2个测量项目差异处于统计学临界(t=1.961、2.019),其他10个测量项目差异均有统计学意义(t=3.725~12.712,P<0.01). 结论 三维扫描的人体测量方法与手工测量方法测量结果虽有差异,但测量的数值范围和偏离程度均处于正常范围.三维扫描测量可用于一般工程设计和采用分型分号的人体装备设计.测点的精确定位和测量人员的技能对测量结果有较大影响,可进一步改进.三维扫描的人体头面部测量方法是一种可用的快速测量方法.%Objective To study the head anthropometric measurements from scanning 3-D images,and to evaluate the scanning techniques against traditional direct head anthropometric measurements.Methods We captured 150 Chinese male pilots' head 3-D images by a special designed non-contact scan

  12. Hydraulic characterization of a sealed loamy soil in a Mediterranean vineyard

    Science.gov (United States)

    Alagna, Vincenzo; Di Prima, Simone; Bagarello, Vincenzo; Guaitoli, Fabio; Iovino, Massimo; Keesstra, Saskia; Cerdà, Artemi

    2017-04-01

    Water infiltration measurements constitute a common way for an indirect characterization of sealed/crusted soils (Alagna et al., 2013). The Beerkan Estimation of Soil Transfer (BEST) parameters procedure by Lassabatere et al. (2006) is very attractive for practical use since it allows an estimation of both the soil water retention and hydraulic conductivity functions. The BEST method considers certain analytical formulae for the hydraulic characteristic curves and estimates their shape parameters, which are texture dependent, from particle-size analysis by physical-empirical pedotransfer functions. Structure dependent scale parameters are estimated by a beerkan experiment, i.e. a three-dimensional (3D) field infiltration experiment at ideally zero pressure head. BEST substantially facilitates the hydraulic characterization of unsaturated soils, and it is gaining popularity in soil science (Bagarello et al., 2014a; Di Prima, 2015; Di Prima et al., 2016b). Bagarello et al. (2014b) proposed a beerkan derived procedure to explain surface runoff and disturbance phenomena at the soil surface occurring during intense rainfall events. Di Prima et al. (2016a) applied this methodology in a vineyard with a sandy-loam texture. These authors compared this simple methodology with rainfall simulation experiments establishing a physical link between the two methodologies through the kinetic energy of the rainfall and the gravitational potential energy of the water used for the beerkan runs. They also indirectly demonstrated the occurrence of a certain degree of compaction and mechanical breakdown using a minidisk infiltrometer (Decagon, 2014). With this device, they reported a reduction of the unsaturated hydraulic conductivity by 2.3 times, due to the seal formation. The ability of the BEST method to distinguish between crusted and non-crusted soils was demonstrated by Souza et al. (2014). However, the potential of the beerkan runs to detect the effect of the seal on flow and

  13. Outburst Prevention Technology with Borehole Hydraulic Jet Through Strata in Floor Gateway%底板巷穿层钻孔水力冲孔防突技术

    Institute of Scientific and Technical Information of China (English)

    刘明举; 郭献林; 李波; 王冕

    2011-01-01

    针对新安矿14211运输巷掘进过程中面临的煤与瓦斯突出问题,为了研究和确定适合新安煤田三软煤层赋存特点的水力冲孔工艺和消突评价体系,使其快速消除工作面突出危险性,提高煤巷掘进速度,采用底板巷穿层钻孔水力冲孔防突措施,按照考察出的冲孔影响半径均匀布置钻孔,排出部分煤体和瓦斯,使煤体卸压增透.试验结果表明,底板巷穿层水力冲孔技术较好地适应和利用了三软煤层的赋存特点,消除了工作面的突出危险性,掘进速度也由之前的40 m/月提高到75m/月,提高了87.5%.%According to coal and gas outburst problems occurred in the heading process of the No.14211 transportation gateway in Xin'an Mine, in order to study and set up the borehole hydraulic jet technique and the outburst evaluation system suitable for the three soft seam deposit features in Xin'an Coalfield, to rapidly eliminate the outburst danger of the heading face and to improve the seam gateway heading speed, the outburst prevention measures with borehole hydraulic jet through the strata in the floor gateway were applied.According the investigation of the borehole hydraulic jet influence radius, a layout of the berehole pattern was evenly set up and a partial coal and gas could be discharged.Thus the seam pressure could be released and the permeability of the seam could be improved.The experiment result showed that the borehole hydraulic jet technology passed through strata in the floor gateway would be well suitable for and utilization of the deposit features of the three soft seam and could eliminate the outburst danger of the heading face.Thus the heading speed could be improved from the previous 40 m/month to 75 m/month and the heading efficiency was improved by 87.5%.

  14. Hydraulic Conductivity of Residual Soil-Cement Mix

    Science.gov (United States)

    Govindasamy, P.; Taha, M. R.

    2016-07-01

    In Malaysia, although there are several researches on engineering properties of residual soils, however study on the hydraulic conductivity properties of metasedimentary residual soils is still lacking. Construction of containment walls like slurry wall techniques can be achieved with hydraulic conductivity of approximately 5 x 10-7cm/sec. The objectives of the study were to determine the physical properties of metasedimentary residual soils and to determine the influence of 1%, 3%, 5% and 10% of cement on hydraulic conductivity parameters. The coefficient of hydraulic conductivity of the soil naturally and soil-cement mixtures were determined by using the falling head test. According to the test, the hydraulic conductivity of the original soil was 4.16 x 10-8 m/s. The value decreases to 3.89 x 10-8 m/s, 2.78 x 10-8 m/s then 6.83 x 10-9 m/s with the addition of 1%, 3% and 5% of cement additives, respectively. During the hydration process, cement hydrates is formed followed by the increase in pH value and Ca(OH)2 which will alter the modification of pores size and distribution. When the quantity of cement increases, the pores size decrease. But, the addition of 10% cement gives an increased hydraulic conductivity value to 2.78 x 10-8 m/s. With 10%, the pore size increase might due to flocculation and agglomeration reaction. The generated hydraulic conductivity values will indirectly become a guide in the preliminary soil cement stabilization to modify the properties of the soil to become more like the properties of a soft rock.1. Introduction

  15. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  16. Numerical modeling of the effect of variation of boundary conditions on vadose zone hydraulic properties

    Directory of Open Access Journals (Sweden)

    Tairone Paiva Leão

    2011-02-01

    Full Text Available An accurate estimation of hydraulic fluxes in the vadose zone is essential for the prediction of water, nutrient and contaminant transport in natural systems. The objective of this study was to simulate the effect of variation of boundary conditions on the estimation of hydraulic properties (i.e. water content, effective unsaturated hydraulic conductivity and hydraulic flux in a one-dimensional unsaturated flow model domain. Unsaturated one-dimensional vertical water flow was simulated in a pure phase clay loam profile and in clay loam interlayered with silt loam distributed according to the third iteration of the Cantor Bar fractal object Simulations were performed using the numerical model Hydrus 1D. The upper and lower pressure heads were varied around average values of -55 cm for the near-saturation range. This resulted in combinations for the upper and lower constant head boundary conditions, respectively, of -50 and -60 cm, -40 and -70 cm, -30 and -80 cm, -20 and -90 cm, and -10 and -100 cm. For the drier range the average head between the upper and lower boundary conditions was set to -550 cm, resulting in the combinations -500 and -600 cm, -400 and -700 cm, -300 and -800 cm, -200 and -900 cm, and -100 and -1,000 cm, for upper and lower boundary conditions, respectively. There was an increase in water contents, fluxes and hydraulic conductivities with the increase in head difference between boundary conditions. Variation in boundary conditions in the pure phase and interlayered one-dimensional profiles caused significant deviations in fluxes, water contents and hydraulic conductivities compared to the simplest case (a head difference between the upper and lower constant head boundaries of 10 cm in the wetter range and 100 cm in the drier range.

  17. Effect of the method of estimation of soil saturated hydraulic conductivity with regards to the design of stormwater infiltration trenches

    Science.gov (United States)

    Paiva coutinho, Artur; Predelus, Dieuseul; Lassabatere, Laurent; Ben Slimene, Erij; Celso Dantas Antonino, Antonio; Winiarski, Thierry; Joaquim da Silva Pereira Cabral, Jaime; Angulo-Jaramillo, Rafael

    2014-05-01

    Best management practices are based on the infiltration of stormwater (e.g. infiltration into basins or trenches) to reduce the risk of flooding of urban areas. Proper estimations of saturated hydraulic conductivity of the vadose zone are required to avoid inappropriate design of infiltration devices. This article aims at assessing (i) the method-dependency of the estimation of soils saturated hydraulic conductivity and (ii) the consequences of such dependency on the design of infiltration trenches. This is illustrated for the specific case of an infiltration trench to be constructed to receive stormwater from a specific parking surface, 250 m2 in area, in Recife (Brazil). Water infiltration experiments were conducted according to the Beerkan Method, i.e. application of a zero water pressure head through a disc source (D=15 cm) and measures of the amount of infiltrated water with time. Saturated hydraulic conductivity estimates are derived from the analysis of these infiltration tests using several different conceptual approaches: one-dimensional models of Horton(1933) and Philip(1957), three-dimensional methods recently developed (Lassabatere et al., 2006, Wu et al., 1999, and Bagarello et al., 2013) and direct 3-dimensional numerical inversion. The estimations for saturated hydraulic conductivity ranged between 65.5 mm/h and 94 mm/h for one-dimensional methods, whereas using three-dimensional methods saturated hydraulic conductivity ranged between 15.6 mm/h and 50 mm/h. These results shows the need for accounting for 3D geometry, and more generally, the physics of water infiltration in soils, if a proper characterization of soil saturated hydraulic conductivity is targeted. In a second step, each estimate of the saturated hydraulic conductivity was used to calculate the stormwater to be stored in the studied trench for several rainfall events of recurrence intervals of 2 to 25 years. The calculation of these volumes showed a great sensitivity with regards to the

  18. The helical turbine: A new idea for low-head hydro

    Energy Technology Data Exchange (ETDEWEB)

    Gorlov, A.M. [Northeastern Univ., Boston, MA (United States)

    1995-09-01

    Substantial potential exists at small hydro sites where heads are too low for conventional hydraulic turbines. A spiral-bladed turbine may offer a new alternative for tapping that potential in a cost-efficient manner.

  19. STOCHASTIC ANALYSIS OF UNSATURATED FLOW WITH THE NORMAL DISTRIBUTION OF SOIL HYDRAULIC CONDUCTIVITY

    Institute of Scientific and Technical Information of China (English)

    Huang Guan-hua; Zhang Ren-duo

    2003-01-01

    Stochastic approaches are useful to quantitatively describe transport behavior over large temporal and spatial scales while accounting for the influence of small-scale variabilities. Numerous solutions have been developed for unsaturated soil water flow based on the lognormal distribution of soil hydraulic conductivity. To our knowledge, no available stochastic solutions for unsaturated flow have been derived on the basis of the normal distribution of hydraulic conductivity. In this paper, stochastic solutions were developed for unsaturated flow by assuming the normal distribution of saturated hydraulic conductivity (Ks). Under the assumption that soil hydraulic properties are second-order stationary, analytical expressions for capillary tension head variance (σ2h) and effective hydraulic conductivity (K*ii) in stratified soils were derived using the perturbation method. The dependence of σ2h and K*ii on soil variability and mean flow variables (the mean capillary tension head and its temporal and spatial gradients) and mean flow conditions (wetting and drying) were systematically analyzed. The calculated variance of capillary tension head with the analytical solution derived in this paper was compared with field experimental data. The good agreement indicates that the analytical solution is applicable to evaluate the variance of capillary tension head of field soils with moderate variability.

  20. Hydraulic rams; a comparative investigation

    NARCIS (Netherlands)

    Tacke, J.H.P.M.

    1988-01-01

    A mathematical model describing the essential features of hydraulic ram operation is developed in order to clarify the possibilities and limitations of the ram relative to its site and its adjustments. The model distinguishes three different periods in the pumping cycle of the hydraulic ram: acceler

  1. Hydraulics. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on hydraulics is one of a series of power mechanics texts and visual aids for training in the servicing of agricultural and industrial machinery. Focus is on oil hydraulics. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The twelve chapters focus…

  2. Sensitivity of soil water content simulation to different methods of soil hydraulic parameter characterization as initial input values

    Science.gov (United States)

    Rezaei, Meisam; Seuntjens, Piet; Shahidi, Reihaneh; Joris, Ingeborg; Boënne, Wesley; Cornelis, Wim

    2016-04-01

    Soil hydraulic parameters, which can be derived from in situ and/or laboratory experiments, are key input parameters for modeling water flow in the vadose zone. In this study, we measured soil hydraulic properties with typical laboratory measurements and field tension infiltration experiments using Wooding's analytical solution and inverse optimization along the vertical direction within two typical podzol profiles with sand texture in a potato field. The objective was to identify proper sets of hydraulic parameters and to evaluate their relevance on hydrological model performance for irrigation management purposes. Tension disc infiltration experiments were carried out at five different depths for both profiles at consecutive negative pressure heads of 12, 6, 3 and 0.1 cm. At the same locations and depths undisturbed samples were taken to determine the water retention curve with hanging water column and pressure extractors and lab saturated hydraulic conductivity with the constant head method. Both approaches allowed to determine the Mualem-van Genuchten (MVG) hydraulic parameters (residual water content θr, saturated water content θs,, shape parameters α and n, and field or lab saturated hydraulic conductivity Kfs and Kls). Results demonstrated horizontal differences and vertical variability of hydraulic properties. Inverse optimization resulted in excellent matches between observed and fitted infiltration rates in combination with final water content at the end of the experiment, θf, using Hydrus 2D/3D. It also resulted in close correspondence of  and Kfs with those from Logsdon and Jaynes' (1993) solution of Wooding's equation. The MVG parameters Kfs and α estimated from the inverse solution (θr set to zero), were relatively similar to values from Wooding's solution which were used as initial value and the estimated θs corresponded to (effective) field saturated water content θf. We found the Gardner parameter αG to be related to the optimized van

  3. Non-stationary flow of hydraulic oil in long pipe

    Directory of Open Access Journals (Sweden)

    Hružík Lumír

    2014-03-01

    Full Text Available The paper deals with experimental evaluation and numerical simulation of non-stationary flow of hydraulic oil in a long hydraulic line. Non-stationary flow is caused by a quick closing of valves at the beginning and the end of the pipe. Time dependence of pressure is measured by means of pressure sensors at the beginning and the end of the pipe. A mathematical model of a given circuit is created using Matlab SimHydraulics software. The long line is simulated by means of segmented pipe. The simulation is verified by experiment.

  4. KJRR-FAI Hydraulic Flow Testing Input Package

    Energy Technology Data Exchange (ETDEWEB)

    N.E. Woolstenhulme; R.B. Nielson; D.B. Chapman

    2013-12-01

    The INL, in cooperation with the KAERI via Cooperative Research And Development Agreement (CRADA), undertook an effort in the latter half of calendar year 2013 to produce a conceptual design for the KJRR-FAI campaign. The outcomes of this effort are documented in further detail elsewhere [5]. The KJRR-FAI was designed to be cooled by the ATR’s Primary Coolant System (PCS) with no provision for in-pile measurement or control of the hydraulic conditions in the irradiation assembly. The irradiation assembly was designed to achieve the target hydraulic conditions via engineered hydraulic losses in a throttling orifice at the outlet of the irradiation vehicle.

  5. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  6. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  7. Measuring quality of life in patients with head and neck cancer: Update of the EORTC QLQ-H&N Module, Phase III

    DEFF Research Database (Denmark)

    Singer, Susanne; Araújo, Cláudia; Arraras, Juan Ignacio;

    2015-01-01

    BACKGROUND: The objective of this study was to pilot test an updated version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module (EORTC QLQ-H&N60). METHODS: Patients with head and neck cancer were asked to complete a list of 60 head...

  8. Hydraulic behaviour of the floating wave energy converter Wave Dragon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The objective of the project is to establish a scale 1:4.5 test model of the floating offshore wave energy converter - Wave Dragon - for testing at 5 m water depth in the Inlet Nissum Bredning. The test model will be equipped with an existing diameter 340 mm model turbine plus additional outlet tubes simulating the resistance from 1 - 16 turbines. The model will be designed to stay afloat even with a total loss of air pressure in the open bottom buoyancy chambers. The test series will primarily focus on measurements of hydraulic response, forces in the mooring system and overtopping quantities. Also data such as head, rotational speed and power production from the turbine will be monitored during the whole test period. The project will verify the effect of the pressured air buoyancy system, which cannot be scaled correctly in laboratory scale models. The test results will allow for an evaluation of the Wave Dragon power production as a function of sea state and freeboard height, in order to calibrate the existing WD-power simulation software. The model can be utilized for further testing of turbine regulation and stress and strain in the structure, establishing the necessary knowledge base for deploying a full-scale demonstration plant. This CD-ROM contains various videos, reports, notes, conference papers and Power Point presentations on the making of the wave energy converter Wave Dragon. (BA)

  9. The determination of the operation parameters at the axial hydraulic turbine

    Science.gov (United States)

    Simedru, A. I.

    2016-08-01

    In the operating point of the monitoring moment there are assumed from process the monitoring measured parameters: the active and reactive power, upstream and downstream water levels (after the intake trash rake and at the outlet of the turbine draft tube), wicket gate and runner opening blades, the differential pressure in the spiral chamber and the hydrounit speed. So, there was established the characteristic curves obtained on analytic basis and similitude and compared with the curves measured experimentally on the hydraulic machines from the power plant. The cavitational coefficient of the machine and the cavitational coefficient of the equipment are in function of the system parameters between them especially the suction head, the runner and wicket gates blades angles of opening. The solution proposed is a method of determining the operating turbine parameters and of the cavitation, by reducing the error caused by the similitude phenomenon, using an accurate estimation of the turbine operating parameters according to the universal diagram of the turbine. The numerical obtained values permit the necessary correlation through a complex function which is able to reduce or eliminate the unwished effects of the cavitation phenomena on the hydraulic turbines of the Iron Gates power plant.

  10. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

    As wind turbines increase in size, combined with increased lifetime demands, new methods for load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and hereby dampen the loads to the system, which is the focus of the current paper. By utilizing...... the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in critical components. Results shows that a significant reduction in fatigue and extreme loads to the yaw...... system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct...

  11. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

    Hansen, M. R.; Andersen, T. O.; Nielsen, B.

    2003-01-01

    system for agricultural applications and driving for transportation. During tranport phases, the lack of suspension causes the vehicle to bounce and pitch, and makes it difficalt to control. Many systems have been proposed to cope with the oscillatory behavior, and different solutions exist. Common......This paper present and discusses R&D results on electro hydraulic hitch control for off-road vehicle, in particular active damping of oscillation occuring on tractors. The research deals with analysis and control of the oscillations occuring on tractors which are design without any susspection...... for most of the systems are that they operate on the hydrailc actuators generally providing the motive forces for moving the implement and/or attachment, typically a plough. The basic idea and physical working principle are to use the implement, moveable relative to the vehicle, as a damper mass. The paper...

  12. Hydraulic characteristics of HANARO fuel bundles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S.; Chung, H. J.; Chun, S. Y.; Yang, S. K.; Chung, M. K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    This paper presents the hydraulic characteristics measured by using LDV (Laser Doppler Velocimetry) in subchannels of HANARO, KAERI research reactor, fuel bundle. The fuel bundle consists of 18 axially finned rods with 3 spacer grids, which are arranged in cylindrical configuration. The effects of the spacer grids on the turbulent flow were investigated by the experimental results. Pressure drops for each component of the fuel bundle were measured, and the friction factors of fuel bundle and loss coefficients for the spacer grids were estimated from the measured pressure drops. Implications regarding the turbulent thermal mixing were discussed. Vibration test results measured by using laser vibrometer were presented. 9 refs., 12 figs. (Author)

  13. Predicting saturated hydraulic conductivity using soil morphological properties

    Directory of Open Access Journals (Sweden)

    Gülay Karahan

    2016-01-01

    Full Text Available Many studies have been conducted to predict soil saturated hydraulic conductivity (Ks by parametric soil properties such as bulk density and particle-size distribution. Although soil morphological properties have a strong effect on Ks, studies predicting Ks by soil morphological properties such as type, size, and strength of soil structure; type, orientation and quantity of soil pores and roots and consistency are rare. This study aimed at evaluating soil morphological properties to predict Ks. Undisturbed soil samples (15 cm length and 8.0 cm id. were collected from topsoil (0-15 cm and subsoil (15-30 cm (120 samples with a tractor operated soil sampler at sixty randomly selected sampling sites on a paddy field and an adjecent grassland in Central Anatolia (Cankırı, Turkey. Synchronized disturbed soil samples were taken from the same sampling sites and sampling depths for basic soil analyses. Saturated hydraulic conductivity was measured on the soil columns using a constant-head permeameter. Following the Ks measurements, the upper part of soil columns were covered to prevent evaporation and colums were left to drain in the laboratory. When the water flow through the column was stopped, a subsample were taken for bulk density and then soil columns were disturbed for describing the soil morphological properties. In addition, soil texture, bulk density, pH, field capacity, wilting point, cation exchange capacity, specific surface area, aggregate stability, organic matter, and calcium carbonate were measured on the synchronized disturbed soil samples. The data were divided into training (80 data values and validation (40 data values sets. Measured values of Ks ranged from 0.0036 to 2.14 cmh-1 with a mean of 0.86 cmh-1. The Ks was predicted from the soil morphological and parametric properties by stepwise multiple linear regression analysis. Soil structure class, stickiness, pore-size, root-size, and pore-quantity contributed to the Ks prediction

  14. Hydraulic Aspects of Vegetation Maintanence in Streams

    DEFF Research Database (Denmark)

    Larsen, Torben; Vestergaard, Kristian

    1991-01-01

    This paper describes the importance of the underwater vegetation on Danish streams and some of the consequences of vegetation maintenance. the influence of the weed on the hydraulic conditions is studied through experiments in a smaller stream and the effect of cutting channels through the weed...... is measured. A method for predicting the Manning's n as a function of the discharge conditions is suggested, and also a working hypothesis for predictions of the effect of channel cutting is presented....

  15. A gamma-ray telescope for on-line measurements of low boron concentrations in a head-phantom for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Verbakel, W.F.A.R.

    1996-06-01

    In Boron Neutron Capture Therapy the {sup 10}B(n, {alpha}){sup 7}Li reaction is used to create a tumour destructing field by the emitted high-LET (Linear Energy Transfer) particles. This reaction is accompanied by the emission of a photon of energy 478 keV. This can serve as a probe for detection of the reaction rate and thereby provide a tool to assess the boron concentration during therapy. An experimental configuration has been designed for on-line measurements of the {sup 10}B prompt gamma rays in a background of hydrogen neutron capture prompt gamma rays, neutrons and gamma rays coming from the reactor. At a facility with epithermal neutrons of the Low Flux Reactor a head phantom has been irradiated with neutorns. This phantom is filled with water and a small volume of 7.8 cm{sup 3} containing 62 ppm {sup 10}B, simulating a tumour. The experimental configuration for prompt gamma measurements has been expanded to perform tomography. The reconstruction of the position and the size of the tumour and its boron cencentration appeared to be possible. The first experiments at the therapy room in the High Flux Reactor showed that this method can probably be expanded for on-line monitoring of the total boron amount in a patients head. Next to this, Monte Carlo calculations and foil activation measurements have been performed to obtain the neutron spectrum of the epithermal beam of the LFR. With the insight achieved with these calculations it has been possible to optimize the total neutron flux. By introduction of a graphite scatter in the beam tube close to the reactr core, the flux has been rainsed with about 65%. With the computer code DORT neutron distributions over the phantom have been calculated for 47 energy groups. These calculations are necessary for ultimate boron tomography. (orig.).

  16. A semi-analytical generalized Hvorslev formula for estimating riverbed hydraulic conductivity with an open-ended standpipe permeameter

    Science.gov (United States)

    Pozdniakov, Sergey P.; Wang, Ping; Lekhov, Mikhail V.

    2016-09-01

    The well-known Hvorslev (1951) formula was developed to estimate soil permeability using single-well slug tests and has been widely applied to determine riverbed hydraulic conductivity using in situ standpipe permeameter tests. Here, we further develop a general solution of the Hvorslev (1951) formula that accounts for flow in a bounded medium and assumes that the bottom of the river is a prescribed head boundary. The superposition of real and imaginary disk sources is used to obtain a semi-analytical expression of the total hydraulic resistance of the flow in and out of the pipe. As a result, we obtained a simple semi-analytical expression for the resistance, which represents a generalization of the Hvorslev (1951). The obtained expression is benchmarked against a finite-element numerical model of 2-D flow (in r-z coordinates) in an anisotropic medium. The results exhibit good agreement between the simulated and estimated riverbed hydraulic conductivity values. Furthermore, a set of simulations for layered, stochastically heterogeneous riverbed sediments was conducted and processed using the proposed expression to demonstrate the potential associated with measuring vertical heterogeneity in bottom sediments using a series of standpipe permeameter tests with different lengths of pipe inserted into the riverbed sediments.

  17. Hydraulic forces contribute to left ventricular diastolic filling

    Science.gov (United States)

    Maksuti, Elira; Carlsson, Marcus; Arheden, Håkan; Kovács, Sándor J.; Broomé, Michael; Ugander, Martin

    2017-03-01

    Myocardial active relaxation and restoring forces are known determinants of left ventricular (LV) diastolic function. We hypothesize the existence of an additional mechanism involved in LV filling, namely, a hydraulic force contributing to the longitudinal motion of the atrioventricular (AV) plane. A prerequisite for the presence of a net hydraulic force during diastole is that the atrial short-axis area (ASA) is smaller than the ventricular short-axis area (VSA). We aimed (a) to illustrate this mechanism in an analogous physical model, (b) to measure the ASA and VSA throughout the cardiac cycle in healthy volunteers using cardiovascular magnetic resonance imaging, and (c) to calculate the magnitude of the hydraulic force. The physical model illustrated that the anatomical difference between ASA and VSA provides the basis for generating a hydraulic force during diastole. In volunteers, VSA was greater than ASA during 75-100% of diastole. The hydraulic force was estimated to be 10-60% of the peak driving force of LV filling (1-3 N vs 5-10 N). Hydraulic forces are a consequence of left heart anatomy and aid LV diastolic filling. These findings suggest that the relationship between ASA and VSA, and the associated hydraulic force, should be considered when characterizing diastolic function and dysfunction.

  18. Pulsating hydraulic fracturing technology in low permeability coal seams

    Institute of Scientific and Technical Information of China (English)

    Wang Wenchao; Li Xianzhong; Lin Baiquan; Zhai Cheng

    2015-01-01

    Based on the difficult situation of gas drainage in a single coal bed of high gas content and low perme-ability, we investigate the technology of pulsating hydraulic pressure relief, the process of crank plunger movement and the mechanism of pulsating pressure formation using theoretical research, mathematical modeling and field testing. We analyze the effect of pulsating pressure on the formation and growth of fractures in coal by using the pulsating hydraulic theory in hydraulics. The research results show that the amplitude of fluctuating pressure tends to increase in the case where the exit is blocked, caused by pulsating pressure reflection and frictional resistance superposition, and it contributes to the growth of fractures in coal. The crack initiation pressure of pulsating hydraulic fracturing is 8 MPa, which is half than that of normal hydraulic fracturing;the pulsating hydraulic fracturing influence radius reaches 8 m. The total amount of gas extraction is increased by 3.6 times, and reaches 50 L/min at the highest point. The extraction flow increases greatly, and is 4 times larger than that of drilling without fracturing and 1.2 times larger than that of normal hydraulic fracturing. The technology provides a technical measure for gas drainage of high gas content and low permeability in the single coal bed.

  19. Emergency remediation measures of a hydroxyisobutyronitrile spill using hydraulic and hydrochemical barriers and pump and treat system (Rho area-Milan, Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Avanzini, M.; Nespoli, M.; Pagotto, A. [EG Engenireeing Geology, Milano (Italy); Peretta, G.P. [Torino Univ. (Italy). Dipt. di Scienze della Terra

    1998-12-31

    The paper deals about emergency clean-up measures after an accidental contamination by hydroxyisobutyronitrile (acetone cyanohydrin) occurred in a aquifer in the industrial area of ELF-ATOCHEM in Rho (province of Milan). Site investigations and tests carried out for planning barrier wells lay-out, injection wells of hydrogen peroxide and in situ treatment of contaminated soil are illustrated. This combined measures system allowed to obtain a high efficacy in pollutant removal in accordance to the Authority`s requests. The final goal of the remediation system activity was reached fifteen months later: concentrations measured at monitoring wells showed values compatible with standards for drinking water quality.

  20. Pediatric head injury.

    Science.gov (United States)

    Tulipan, N

    1998-01-01

    Pediatric head injury is a public health problem that exacts a high price from patients, their families and society alike. While much of the brain damage in head-injured patients occurs at the moment of impact, secondary injuries can be prevented by aggressive medical and surgical intervention. Modern imaging devices have simplified the task of diagnosing intracranial injuries. Recent advances in monitoring technology have made it easier to assess the effectiveness of medical therapy. These include intracranial pressure monitoring devices that are accurate and safe, and jugular bulb monitoring which provides a continuous, qualitative measure of cerebral blood flow. The cornerstones of treatment remain hyperventilation and osmotherapy. Despite maximal treatment, however, the mortality and morbidity associated with pediatric head injury remains high. Reduction of this mortality and morbidity will likely depend upon prevention rather than treatment.

  1. Stability of Hydraulic Systems with Focus on Cavitating Pumps

    OpenAIRE

    Brennen, C. E.; Braisted, D. M.

    1980-01-01

    Increasing use is being made of transmission matrices to characterize unsteady flows in hydraulic system components and to analyze the stability of such systems. This paper presents some general characteristics which should be examined in any experimentally measured transmission matrices and a methodology for the analysis of the stability of transmission matrices in hydraulic systems of order 2. These characteristics are then examined for cavitating pumps and the predicted instabilities (kn...

  2. Hydraulic conductivity of compacted zeolites.

    Science.gov (United States)

    Oren, A Hakan; Ozdamar, Tuğçe

    2013-06-01

    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  4. The composition and compression of biofilms developed on ultrafiltration membranes determine hydraulic biofilm resistance.

    Science.gov (United States)

    Derlon, Nicolas; Grütter, Alexander; Brandenberger, Fabienne; Sutter, Anja; Kuhlicke, Ute; Neu, Thomas R; Morgenroth, Eberhard

    2016-10-01

    This study aimed at identifying how to improve the level of permeate flux stabilisation during gravity-driven membrane filtration without control of biofilm formation. The focus was therefore on understanding (i) how the different fractions of the biofilms (inorganics particles, bacterial cells, EPS matrix) influence its hydraulic resistance and (ii) how the compression of biofilms impacts its hydraulic resistance, i.e., can water head be increased to increase the level of permeate flux stabilisation. Biofilms were developed on ultrafiltration membranes at 88 and 284 cm water heads with dead-end filtration for around 50 days. A larger water head resulted in a smaller biofilm permeability (150 and 50 L m(-2) h(-1) bar(-1) for biofilms grown at 88 cm and 284 cm water head, respectively). Biofilms were mainly composed of EPS (>90% in volume). The comparison of the hydraulic resistances of biofilms to model fouling layers indicated that most of the hydraulic resistance is due to the EPS matrix. The compressibility of the biofilm was also evaluated by subjecting the biofilms to short-term (few minutes) and long-term variations of transmembrane pressures (TMP). A sudden change of TMP resulted in an instantaneous and reversible change of biofilm hydraulic resistance. A long-term change of TMP induced a slow change in the biofilm hydraulic resistance. Our results demonstrate that the response of biofilms to a TMP change has two components: an immediate variation of resistance (due to compression/relaxation) and a long-term response (linked to biofilm adaptation/growth). Our results provide relevant information about the relationship between the operating conditions in terms of TMP, the biofilm structure and composition and the resulting biofilm hydraulic resistance. These findings have practical implications for a broad range of membrane systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Measured adiposity in relation to head and neck cancer risk in the European Prospective Investigation into Cancer and Nutrition

    DEFF Research Database (Denmark)

    Ward, Heather A; Wark, Petra A; Muller, David C

    2017-01-01

    Investigation into Cancer and Nutrition study (EPIC) with measured anthropometry, there were 837 incident cases of HNC. HNC risk was examined in relation to body mass index (BMI) [lean: 30 kg/m2], waist circumference...

  6. Effect of hydraulic hysteresis on the stability of infinite slopes under steady infiltration

    Science.gov (United States)

    Chen, Pan; Mirus, Benjamin B.; Lu, Ning; Godt, Jonathan W.

    2017-01-01

    Hydraulic hysteresis, including capillary soil water retention (SWR), air entrapment SWR, and hydraulic conductivity, is a common phenomenon in unsaturated soils. However, the influence of hydraulic hysteresis on suction stress, and subsequently slope stability, is generally ignored. This paper examines the influence of each of these three types of hysteresis on slope stability using an infinite slope stability analysis under steady infiltration conditions. First, hypothetical slopes for representative silty and sandy soils are examined. Then a monitored hillslope in the San Francisco Bay Area, California is assessed, using observed rainfall conditions and measured hydraulic and geotechnical properties of the colluvial soil. Results show that profiles of suction stress and the corresponding factor of safety are generally strongly affected by hydraulic hysteresis. Results suggest that each of the three types of hydraulic hysteresis may play a major role in the occurrence of slope failure, indicating that ignoring hydraulic hysteresis will likely lead to underestimates of failure potential and hence to inaccurate slope stability analysis.

  7. FOREWORD: 26th IAHR Symposium on Hydraulic Machinery and Systems

    Science.gov (United States)

    Wu, Yulin; Wang, Zhengwei; Liu, Shuhong; Yuan, Shouqi; Luo, Xingqi; Wang, Fujun

    2012-11-01

    The 26th IAHR Symposium on Hydraulic Machinery and Systems, will be held in Beijing, China, 19-23 August 2012. It is jointly organized by Tsinghua University, State Key Laboratory of Hydro Science and Hydraulic Engineering, China, Jiangsu University, Xi'an University of Technology, China Agricultural University, National Engineering Research Center of Hydropower Equipment and Dongfang Electric Machinery Co., Ltd. It is the second time that China hosts such a symposium. By the end of 2011, the China electrical power system had a total of 1 050 GW installed power, out of which 220 GW was in hydropower plants. The energy produced in hydropower facilities was 662.6 TWh from a total of 4,720 TWh electrical energy production in 2011. Moreover, in 2020, new hydropower capacities are going to be developed, with a total of 180 GW installed power and an estimated 708 TWh/year energy production. And in 2011, the installed power of pumped storage stations was about 25GW. In 2020, the data will be 70GW. At the same time, the number of pumps used in China is increasing rapidly. China produces about 29,000,000 pumps with more than 220 series per year. By the end of 2011, the Chinese pumping system has a total of 950 GW installed power. The energy consumed in pumping facilities was 530 TWh in 2011. The pump energy consumption accounted for about 12% of the national electrical energy production. Therefore, there is a large market in the field of hydraulic machinery including water turbines, pump turbines and a variety of pumps in China. There are also many research projects in this field. For example, we have conducted National Key Research Projects on 1000 MW hydraulic turbine, and on the pump turbines with high head, as well as on the large capacity pumps for water supply. Tsinghua University of Beijing is proud to host the 26th IAHR Symposium on Hydraulic Machinery and Systems. Tsinghua University was established in 1911, after the founding of the People's Republic of China. It

  8. Development of nuclear thermal hydraulic verification tests and evaluation technology - Development of a sensor for two-phase flow measurement using impedance method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moo Whan; Kang, Hie Chan; Kwon, Jung Tae; Huh, Deok; Yang, Hoon Cheul [Pohang University of Science and Technology, Pohang (Korea)

    2000-04-01

    Impedance method was carried out to design the electrode that can measure the void fraction of the bubbly flow in pool reservoir. To find out the optimum electrode shape, Styrofoam-Simulator tests were performed in a specially designed acrylic reservoir. Three kinds of electrodes were designed to compare the measuring characteristics of water-air flow. The resistance increased with the increase of the void fraction and the capacitance decreased with the increase of the void fraction. The resistance is a main parameter to express the nature of the water-air flow in impedance method. Almost of impedance values come out from the resistance. The degree of deviation from the mean-resistance values showed reasonable results. Electrode type-I expressed excellent results among the three electrode shapes. The sensor developed can simultaneously measure the void fraction and the water level. 7 refs., 51 figs., 4 tabs. (Author)

  9. Research on Load Measurement Method of Marine Propulsion Shafting System Based on Hydraulic Jack Method%基于顶举法的船舶推进轴系负荷测试方法研究

    Institute of Scientific and Technical Information of China (English)

    张利军

    2014-01-01

    船舶推进轴系负荷测试是轴系安装过程和检验过程中不可缺少的环节,通过有效的检验方法,检测中间轴承以及主机的主轴承所承受的实际负荷是否在理论计算允许的范围之内。本文介绍了基于顶举法的轴承负荷测量原理、测量过程和计算方法。经过实船数据的测量计算,并与应用电阻应变片法测量数据比较和分析,说明该方法在船舶推进轴系负荷测试的可行性和经济性。%The load measurement of marine propulsion shafting system is an indispensable link in installation and inspection process. The actual bearing load of the intermediate bearings and main bearing within or within-out the allowed range of theoretical calculation is checked by using effective testing method. Based on the hydraulic jack method, the measurement principle, measuring process and calculation method are discussed. After measurement and calculation for an actual ship, the result is compared and analyzed with measuring data by strain gauge method. The results show that the method is economical and feasible in the load test of ship propulsion shafting.

  10. A low cost apparatus for measuring the xylem hydraulic conductance in plants Um aparato de baixo custo para medição da condutância hidráulica do xilema em plantas

    Directory of Open Access Journals (Sweden)

    Luciano Pereira

    2012-01-01

    Full Text Available Plant yield and resistance to drought are directly related to the efficiency of the xylem hydraulic conductance and the ability of this system to avoid interrupting the flow of water. In this paper we described in detail the assembling of an apparatus proposed by TYREE et al. (2002, and its calibration, as well as low cost adaptations that make the equipment accessible for everyone working in this research area. The apparatus allows measuring the conductance in parts of roots or shoots (root ramifications or branches, or in the whole system, in the case of small plants or seedlings. The apparatus can also be used to measure the reduction of conductance by embolism of the xylem vessels. Data on the hydraulic conductance of eucalyptus seedlings obtained here and other reports in the literature confirm the applicability of the apparatus in physiological studies on the relationship between productivity and water stress.A produtividade das plantas e a capacidade de resistência à seca estão diretamente relacionadas com a eficiência da condutância hidráulica do xilema e a capacidade desse sistema em evitar a interrupção do fluxo de água. No presente trabalho, detalha-se a montagem de um aparato proposto por TYREE et al. (2002, e sua calibração, bem como adaptações com peças de menor custo que tornam o aparelho acessível a qualquer um trabalhando nesta linha de pesquisa. Esse aparato possibilita medir a condutância de partes do sistema radicular ou da parte aérea (ramificações radiculares ou ramos, ou em todo o sistema, no caso de plantas de porte pequeno ou plântulas. O aparato também pode ser usado para medir a redução da condutância pela embolização dos vasos do xilema. Medições de condutância hidráulica feitas em plântulas de eucalipto e outros trabalhos encontrados na literatura confirmaram a aplicabilidade desse aparato em estudos fisiológicos de produtividade relacionada ao estresse hídrico.

  11. Determination of hydraulic properties of the Callovo-Oxfordian argillite at the bure site: Synthesis of the results obtained in deep boreholes using several in situ investigation techniques

    Science.gov (United States)

    Distinguin, Marc; Lavanchy, Jean-Marc

    Since 1991, ANDRA ( Agence Nationale pour la gestion des Déchets Radioactifs - National Radioactive Waste Management Agency) has been performing research on the possibility of geologic disposal of high level radioactive waste. In 1999, Andra began constructing an Underground Research Laboratory at Bure, a site located on the border of the Meuse-Haute-Marne departments, 300 km East of Paris. The laboratory is investigating the Callovo-Oxfordian argillite, a 130 m thick middle Jurassic stratum, at a depth of about 420 m. Argillite is a clay-rich sedimentary rock with low-permeability. Between 1994 and 2004, Andra collected from deep boreholes an impressive wealth of data covering a wide range of geosciences. This paper focuses on the hydraulic data related to argillite, including the results from short-term hydraulic packer tests and long-term monitoring of the formation pressures. Three types of tools are used on the site for investigations in deep boreholes. The first one is a conventional packer test tool used in the petroleum industry and adapted for hydrogeological purposes. The main objective is to determinate the permeability of the formation through short-term tests (24-72 h) at about 10 regular intervals. The two other types of tool are permanent monitoring devices. The electromagnetic pressure gauge (EPG) is totally isolated from the surface perturbations. There are no electric or hydraulic lines to the surface and the borehole is cemented. The advantage of this tool is that the formation almost recovers its initial pressure, avoiding disturbances from surface. Although the multi-packer equipment, installed in an open borehole can be affected by surface perturbations, it is used to measure pressure at different isolated levels in the same borehole ( i. e., 11 chambers in one borehole). Evaluations of the formation pressure (freshwater head) and hydraulic conductivity have been performed for all intervals investigated (19 short-term packer tests and 15 long

  12. Method to Estimate the Dissolved Air Content in Hydraulic Fluid

    Science.gov (United States)

    Hauser, Daniel M.

    2011-01-01

    In order to verify the air content in hydraulic fluid, an instrument was needed to measure the dissolved air content before the fluid was loaded into the system. The instrument also needed to measure the dissolved air content in situ and in real time during the de-aeration process. The current methods used to measure the dissolved air content require the fluid to be drawn from the hydraulic system, and additional offline laboratory processing time is involved. During laboratory processing, there is a potential for contamination to occur, especially when subsaturated fluid is to be analyzed. A new method measures the amount of dissolved air in hydraulic fluid through the use of a dissolved oxygen meter. The device measures the dissolved air content through an in situ, real-time process that requires no additional offline laboratory processing time. The method utilizes an instrument that measures the partial pressure of oxygen in the hydraulic fluid. By using a standardized calculation procedure that relates the oxygen partial pressure to the volume of dissolved air in solution, the dissolved air content is estimated. The technique employs luminescent quenching technology to determine the partial pressure of oxygen in the hydraulic fluid. An estimated Henry s law coefficient for oxygen and nitrogen in hydraulic fluid is calculated using a standard method to estimate the solubility of gases in lubricants. The amount of dissolved oxygen in the hydraulic fluid is estimated using the Henry s solubility coefficient and the measured partial pressure of oxygen in solution. The amount of dissolved nitrogen that is in solution is estimated by assuming that the ratio of dissolved nitrogen to dissolved oxygen is equal to the ratio of the gas solubility of nitrogen to oxygen at atmospheric pressure and temperature. The technique was performed at atmospheric pressure and room temperature. The technique could be theoretically carried out at higher pressures and elevated

  13. Development of nuclear thermal hydraulic verification tests and evaluation technology - Development of the ultrasonic method for two-phase mixture level measurement in nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    No, Hee Cheon; Kim, Sang Jae; Kim, Hyung Tae; Moon, Young Min [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    2000-04-01

    An ultrasonic method is developed for the measurement of the two-phase mixture level in the reactor vessel or steam generator. The ultrasonic method is selected among the several non-nuclear two-phase mixture level measurement methods through two steps of selection procedure. A commercial ultrasonic level measurement method is modified for application into the high temperature, pressure, and other conditions. The calculation method of the ultrasonic velocity is modified to consider the medium as the homogeneous mixture of air and steam, and to be applied into the high temperature and pressure conditions. The cross-correlation technique is adopted as a detection method to reduced the effects of the attenuation and the diffused reflection caused by surface fluctuation. The waveguides are developed to reduce the loss of echo and to remove the effects of obstructs. The present experimental study shows that the developed ultrasonic method measures the two-phase mixture level more accurately than the conventional methods do. 21 refs., 60 figs., 13 tabs. (Author)

  14. New parameters influencing hydraulic runner lifetime

    Science.gov (United States)

    Sabourin, M.; Thibault, D.; Bouffard, D. A.; Lévesque, M.

    2010-08-01

    Traditionally, hydraulic runner mechanical design is based on calculation of static stresses. Today, validation of hydraulic runner design in terms of reliability requires taking into account the fatigue effect of dynamics loads. A damage tolerant approach based on fracture mechanics is the method chosen by Alstom and Hydro-Québec to study fatigue damage in runners. This requires a careful examination of all factors influencing material fatigue behavior. Such material behavior depends mainly on the chemical composition, microstructure and thermal history of the component, and on the resulting residual stresses. Measurement of fracture mechanics properties of various steels have demonstrated that runner lifetime can be significantly altered by differences in the manufacturing process, although remaining in accordance with agreed practices and standards such as ASTM. Carbon content and heat treatment are suspected to influence fatigue lifetime. This will have to be investigated by continuing the current research.

  15. Advanced Hydraulic Studies on Enhancing Particle Removal

    DEFF Research Database (Denmark)

    He, Cheng

    The removal of suspended solids and attached pollutants is one of the main treatment processes in wastewater treatment. This thesis presents studies on the hydraulic conditions of various particle removal facilities for possible ways to increase their treatment capacity and performance by utilizing...... and improving hydraulic conditions. Unlike most traditional theses which usually focus only on one particular subject of study, this thesis contains four relatively independent studies which cover the following topics: a newly proposed particle settling enhancement plate, the redesign of the inlet zone......, introduction and conclusions as well as the study results. All studies were carried out with a combination of numerical model and measurements. In the first part of the thesis a new concept of using a vortex to increase particle removal from liquid was proposed and the new particle settling enhancement plates...

  16. Thermal Hydraulic Design of PWT Accelerating Structures

    CERN Document Server

    Yu, David; Chen Ping; Lundquist, Martin; Luo, Yan

    2005-01-01

    Microwave power losses on the surfaces of accelerating structures will transform to heat which will deform the structures if it is not removed in time. Thermal hydraulic design of the disk and cooling rods of a Plane Wave Transformer (PWT) structure is presented. Experiments to measure the hydraulic (pressure vs flow rate) and cooling (heat removed vs flow rate) properties of the PWT disk are performed, and results compared with simulations using Mathcad models and the COSMOSM code. Both experimental and simulation results showed that the heat deposited on the structure could be removed effectively using specially designed water-cooling circuits and the temperature of the structure could be controlled within the range required.

  17. HYDRAULICS, ATHENS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  18. HYDRAULICS, JACKSON COUNTY, KENTUCKY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  19. HYDRAULICS, MADISON COUNTY, ALABAMA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Hydraulic data was reviewed and approved by FEMA during the initial MT-2 processing. Recent developments in digital terrain and geospatial database management...

  20. HYDRAULICS, HAMPDEN COUNTY, MA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data in this submittal include spatial datasets and model outputs necessary for computation of the 1-percent flooding extent. The minimum requirement for...

  1. Hydraulic wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The purpose of this research was to design, build and test a hydraulic wind energy system. This design used a three bladed turbine, which drove a hydraulic pump. The energy is transmitted from the pump through a long hose and into a hydraulic motor, where the energy is used. This wind system was built and tested during the winter of 1980-1981. The power train included a five meter, three bladed wind turbine, a 9.8:1 ratio gearbox, a 1.44 cubic inch displacement pump with a small supercharge gear pump attached. The hydraulic fluid was pumped through a 70', 3/4'' I-D-high pressure flexhose, then through a volume control valve and into a 1.44 cubic inch displacement motor. The fluid was returned through a 70', 1'' I-D-flexhose.

  2. Prognosis in head injury.

    Science.gov (United States)

    Jane, J A; Rimel, R W

    1982-01-01

    The prognosis of head injury when viewed from the perspective of the Glasgow Coma Scale confirms the utility of this measure. In particular, decrease in mortality is associated with an increase in GCS. In addition, the motor score portion of the GCS was of predictive value when taken alone. The outcome of patients in coma (GCS less than 8) was closely related to three preventable or treatable factors, namely, hypoxia, shock, and increased intracranial pressure. These three factors, when considered in combination, powerfully predicted mortality. Of considerable interest was the finding that moderate head injury (GCS 9-12) was associated with a small but perhaps preventable mortality. The morbidity was intermediate between that of severe and minor and was surprisingly high. Minor head injury, while not associated with significant mortality, also resulted in considerable morbidity. Neuropsychological evaluation of the patients and an experimental study suggests that an organic component may be involved even in this group. To deal with head injury, distinctions must be made between grades of severity. The Glasgow Coma Scale is suited for this task. Nonetheless, the recognition of this basic continuity should elicit the further recognition that different health providers may be involved in the case of, say, severe, as opposed to mild, injury, and that different outcome measures are suitable for one group but not another.

  3. Head Position and Internally Headed Relative Clauses.

    Science.gov (United States)

    Basilico, David

    1996-01-01

    Examines "Head Movement" in internally headed relative clauses (IHRCs). The article shows that in some cases, head movement to an external position need not take place and demonstrates that this movement of the head to a sentence-internal position results from the quantificational nature of IHRCs and Diesing's mapping hypothesis (1990, 1992). (56…

  4. 14 CFR 29.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 29.1435 Section 29.1435... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each element of the hydraulic system...

  5. 14 CFR 23.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 23.1435 Section 23.1435... § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each hydraulic system and its elements must withstand, without yielding, the structural loads expected...

  6. 46 CFR 28.405 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.405 Section 28.405 Shipping... Operate With More Than 16 Individuals on Board § 28.405 Hydraulic equipment. (a) Each hydraulic system... than four times the system maximum operating pressure. (c) Each hydraulic system must be equipped...

  7. Advanced Performance Hydraulic Wind Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  8. Periodic Hydraulic Testing for Discerning Fracture Network Connections

    Science.gov (United States)

    Becker, M.; Le Borgne, T.; Bour, O.; Guihéneuf, N.; Cole, M.

    2015-12-01

    Discrete fracture network (DFN) models often predict highly variable hydraulic connections between injection and pumping wells used for enhanced oil recovery, geothermal energy extraction, and groundwater remediation. Such connections can be difficult to verify in fractured rock systems because standard pumping or pulse interference tests interrogate too large a volume to pinpoint specific connections. Three field examples are presented in which periodic hydraulic tests were used to obtain information about hydraulic connectivity in fractured bedrock. The first site, a sandstone in New York State, involves only a single fracture at a scale of about 10 m. The second site, a granite in Brittany, France, involves a fracture network at about the same scale. The third site, a granite/schist in the U.S. State of New Hampshire, involves a complex network at scale of 30-60 m. In each case periodic testing provided an enhanced view of hydraulic connectivity over previous constant rate tests. Periodic testing is particularly adept at measuring hydraulic diffusivity, which is a more effective parameter than permeability for identify the complexity of flow pathways between measurement locations. Periodic tests were also conducted at multiple frequencies which provides a range in the radius of hydraulic penetration away from the oscillating well. By varying the radius of penetration, we attempt to interrogate the structure of the fracture network. Periodic tests, therefore, may be uniquely suited for verifying and/or calibrating DFN models.

  9. Effects of Volute Design and Number of Impeller Blades on Lateral Impeller Forces and Hydraulic Performance

    Directory of Open Access Journals (Sweden)

    Daniel O. Baun

    2003-01-01

    Full Text Available A comparison is made between the characteristics of the measured lateral impeller forces and the hydraulic performances of a four- and a five-vane impeller, each operating in a spiral volute, a concentric volute, and a double volute. The pump's rotor was supported in magnetic bearings. In addition to supporting and controlling the rotor motion, the magnetic bearings also served as active load cells and were used to measure the impeller forces acting on the pump's rotor. The lateral impeller force characteristics, as a function of a normalized flow coefficient, were virtually identical in the four- and five-vane impellers in each respective volute type. The measured impeller forces for each volute type were compared with correlations in the literature. The measured forces from the double volute configurations agreed with the forces from a correlation model over the full flow range. Single volute configurations compared well with the predictions of a published correlation at high flow rates, ϕ/ϕn>0.5. Concentric volute configurations compared well with a published correlation at low flow rates, ϕ/ϕn<0.4. The head-versus-flow characteristics of the four-vane impeller in each volute type were stable over a greater flow range than the corresponding characteristics of the five-vane impeller. At higher flow rates in the stable region of the head's characteristic curves near the best efficiency point, the five-vane impeller produced higher head than did the four-vane impeller in each volute type.

  10. Equivalent Porous Media (EPM) Simulation of Groundwater Hydraulics and Contaminant Transport in Karst Aquifers.

    Science.gov (United States)

    Ghasemizadeh, Reza; Yu, Xue; Butscher, Christoph; Hellweger, Ferdi; Padilla, Ingrid; Alshawabkeh, Akram

    2015-01-01

    Karst aquifers have a high degree of heterogeneity and anisotropy in their geologic and hydrogeologic properties which makes predicting their behavior difficult. This paper evaluates the application of the Equivalent Porous Media (EPM) approach to simulate groundwater hydraulics and contaminant transport in karst aquifers using an example from the North Coast limestone aquifer system in Puerto Rico. The goal is to evaluate if the EPM approach, which approximates the karst features with a conceptualized, equivalent continuous medium, is feasible for an actual project, based on available data and the study scale and purpose. Existing National Oceanic Atmospheric Administration (NOAA) data and previous hydrogeological U. S. Geological Survey (USGS) studies were used to define the model input parameters. Hydraulic conductivity and specific yield were estimated using measured groundwater heads over the study area and further calibrated against continuous water level data of three USGS observation wells. The water-table fluctuation results indicate that the model can practically reflect the steady-state groundwater hydraulics (normalized RMSE of 12.4%) and long-term variability (normalized RMSE of 3.0%) at regional and intermediate scales and can be applied to predict future water table behavior under different hydrogeological conditions. The application of the EPM approach to simulate transport is limited because it does not directly consider possible irregular conduit flow pathways. However, the results from the present study suggest that the EPM approach is capable to reproduce the spreading of a TCE plume at intermediate scales with sufficient accuracy (normalized RMSE of 8.45%) for groundwater resources management and the planning of contamination mitigation strategies.

  11. Cam deformity and the omega angle, a novel quantitative measurement of femoral head-neck morphology: a 3D CT gender analysis in asymptomatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, Vasco V.; Gaspar, Augusto [Hospital da Luz, MSK imaging Unit (UIME), Imaging Center, Lisbon (Portugal); Rego, Paulo [Hospital da Luz, Department of Orthopaedic Surgery, Lisbon (Portugal); Dantas, Pedro [Hospital CUF Descobertas, Lisbon (Portugal); Soldado, Francisco [Universitat de Barcelona, Hospital Sant Joan de Deu, Barcelona (Spain); Consciencia, Jose G. [NOVA Medical School, Lisbon (Portugal)

    2017-05-15

    Our objectives were to use 3D computed tomography (CT) to define head-neck morphologic gender-specific and normative parameters in asymptomatic individuals and use the omega angle (Ω ) to provide quantification data on the location and radial extension of a cam deformity. We prospectively included 350 individuals and evaluated 188 asymptomatic hips that underwent semiautomated CT analysis. Different thresholds of alpha angle (α ) were considered in order to analyze cam morphology and determine Ω . We calculated overall and gender-specific parameters for imaging signs of cam morphology (Ω and circumferential α ). The 95 % reference interval limits were beyond abnormal thresholds found in the literature for cam morphology. Specifically, α at 3/1 oclock were 46.9 /60.8 overall, 51.8 /65.4 for men and 45.7 /55.3 for women. Cam prevalence, magnitude, location, and epicenter were significantly gender different. Increasing α correlated with higher Ω , meaning that higher angles correspond to larger cam deformities. Hip morphometry measurements in this cohort of asymptomatic individuals extended beyond current thresholds used for the clinical diagnosis of cam deformity, and α was found to vary both by gender and measurement location. These results suggest that α measurement is insufficient for the diagnosis of cam deformity. Enhanced morphometric evaluation, including 3D imaging and Ω , may enable a more accurate diagnosis. (orig.)

  12. 5t电液自由锻锤隔振基础及其振动测试%Vibration-isolated foundation of a 50kN electro-hydraulic free forging hammer and its vibration measurement

    Institute of Scientific and Technical Information of China (English)

    杨雪春; 杨国泰; 何成宏; 揭小平

    2001-01-01

    介绍了国产5t电液自由锻锤的隔振装置结构,对其基础振动进行了现场测试。测试结果表明,这种稳定性好、砧座水平可调节的板簧悬吊式砧下直接隔振装置,可使基础振动位移和振动加速度分别降至GB50040-96允许值的15%和3%以下,隔振效果显著。%The 1st home made suspended vibration-isolating installation with an anvil directly supported by leaf springs of a 5t electro-hydraulic free forging hammer has been introduced and measured resulting in that the installation will be satisfactory to stability and easy to horizontal alignment so that the vibration amplitude and vibration acceleration would be decreased to less than 15% and 3% respectively in permissible value according to GB50040-96 hence remarkable effectiveness in vibration isolation.

  13. Avaliação hidráulica de um sistema de irrigação localizada de baixa pressão, projetado pelo software "bubbler" Design and hydraulics evaluation of a low-head microirrigation, bubbler system

    Directory of Open Access Journals (Sweden)

    Ivam H. de Souza

    2005-04-01

    Full Text Available Conduziu-se este trabalho com o objetivo de avaliar o desempenho de um sistema de irrigação a baixa pressão, bubbler, em condições de campo. A avaliação consistiu de um estudo dividido em duas fases, em que, na primeira, foi elaborado o dimensionamento hidráulico do sistema de irrigação, com uso do programa computacional Bubbler versão 1.1, enquanto, na segunda fase, ocorreram a instalação e os testes de campo. Estabeleceram-se as alturas de 0,77; 0,71; 0,68 e 0,67 m na saída das mangueiras emissoras no campo, conforme recomendação do programa. Foram feitas as avaliações de vazão em cada mangueira emissora, para determinar o Coeficiente de Uniformidade de Christiansen (CUC, a Uniformidade de Distribuição (UD e a Eficiência de Aplicação (EA. Os testes mostraram CUC igual a 96,64%, UD igual a 95,85% e EA igual a 86,98%. O sistema no campo proporcionou vazão média de 64,8 L h-1 contra os 79,2 L h-1 estabelecidos pelo programa. Os valores encontrados de vazão diferiram dos valores projetados pelo aplicativo, em conseqüência da variação dos diâmetros e das perdas de carga (linear e localizada que apresentaram desvio-padrão de 0,23 m.This work was done with the objective of evaluating a low-pressure irrigation system (bubbler system, under field conditions. This evaluation consisted of a study divided in two phases: in the first, the hydraulic design of the irrigation system was elaborated with the use of the software named Bubbler version 1.1; while, in the second phase the installation and the field tests were done. Volumetric tests were accomplished in each emission hose to determine: the flow variation, the coefficients of uniformity, and the application efficiency. It was established the heights of the emitter hose exit at 0.77; 0.71; 0.68 and 0.67 m, on the field, following the recommendation of the software. The tests showed a Christiansen's Uniformity Coefficient (CUC of 96.64%, a Distribution Uniformity (DU of

  14. Development of nuclear thermal hydraulic verification test and evaluation technology; study on 3-dimension measurement of two-phase flow parameters in subcooled boiling flow

    Energy Technology Data Exchange (ETDEWEB)

    Park, Goon Cherl; Kim, Moon Oh; Cho, Hyung Kyoo; Kim, Seong Jin [Seoul National University, Seoul (Korea)