Electrical resistivity measurements in superconducting ceramics

International Nuclear Information System (INIS)

Muccillo, R.; Bressiani, A.H.A.; Muccillo, E.N.S.; Bressian, J.C.

1988-01-01

Electrical resistivity measurements have been done in (Y,Ba,Cu,O)- and (Y,Al,Ba,Cu,O)-based superconducting ceramics. The sintered specimens were prepared by applying gold electrodes and winding on the non-metalized part with a copper strip to be immersed in liquid nitrogen for cooling. The resistivity measurements have been done by the four-probe method. A copper constantan or chromel-alumel thermocouple inserted between the specimen and the copper cold finger has been used for the determination of the critical temperature T c . Details of the experimental set-up and resistivity versus temperature plots in the LNT-RT range for the superconducting ceramics are the major contributions of this communication. (author) [pt

Measurement of the electrical resistivity of liquid 32G2 and 32G1 steels by the rotating magnetic field method

Science.gov (United States)

Borovykh, M. A.; Chikova, O. A.; Tsepelev, V. S.; V'yukhin, V. V.

2017-03-01

The resistivity of liquid 32G2 and 32G1 steels are measured using the rotating magnetic field method to obtain information on their liquid structures. The technique of measurements is described and the influence of self-induction and viscosity on the resistivity is estimated. The results are discussed in the framework of a microheterogeneous structure of a metallic melt. A conclusion is made about the character of the influence of slag inclusions detected by magnetic powder and ultrasonic methods on the temperature dependences of the resistivities of liquid 32G2 and 32G1 steels. The change in the temperature coefficient of the resistivity of the melt on heating to 1700°C is interpreted using the Nagel-Tauc model.

Characterizing Fracture Property Using Resistivity Measured at Different Frequencies

Energy Technology Data Exchange (ETDEWEB)

Horne, Roland N. [Stanford Univ., CA (United States); Li, Kewen [Stanford Univ., CA (United States)

2014-09-30

The objective was to develop geophysical approaches to detecting and evaluating the fractures created or existing in EGS and other geothermal reservoirs by measuring the resistivity at different frequencies. This project has been divided into two phases: Phase I (first year): Proof of Concept – develop the resistivity approach and verify the effect of frequency on the resistivity in rocks with artificial or natural fractures over a wide range of frequencies. Phase II: Prototyping Part 1 (second year): measure the resistivity in rocks with fractures of different apertures, different length, and different configurations at different frequencies. Part 2 (third year): develop mathematical models and the resistivity method; infer the fracture properties using the measured resistivity data.

Slipping on pedestrian surfaces: methods for measuring and evaluating the slip resistance.

Science.gov (United States)

Wetzel, Christoph; Windhövel, Ulrich; Mewes, Detlef; Ceylan, Orhan

2015-01-01

Tripping, slipping and falling accidents are among the types of accident with a high incidence. This article describes the requirements concerning slip resistance, as well as the state of the art of slip resistance measurement standards in the European Community and the USA. The article also describes how risk assessment can be performed in the field.

Measurement of microchannel fluidic resistance with a standard voltage meter.

Science.gov (United States)

Godwin, Leah A; Deal, Kennon S; Hoepfner, Lauren D; Jackson, Louis A; Easley, Christopher J

2013-01-03

A simplified method for measuring the fluidic resistance (R(fluidic)) of microfluidic channels is presented, in which the electrical resistance (R(elec)) of a channel filled with a conductivity standard solution can be measured and directly correlated to R(fluidic) using a simple equation. Although a slight correction factor could be applied in this system to improve accuracy, results showed that a standard voltage meter could be used without calibration to determine R(fluidic) to within 12% error. Results accurate to within 2% were obtained when a geometric correction factor was applied using these particular channels. When compared to standard flow rate measurements, such as meniscus tracking in outlet tubing, this approach provided a more straightforward alternative and resulted in lower measurement error. The method was validated using 9 different fluidic resistance values (from ∼40 to 600kPa smm(-3)) and over 30 separately fabricated microfluidic devices. Furthermore, since the method is analogous to resistance measurements with a voltage meter in electrical circuits, dynamic R(fluidic) measurements were possible in more complex microfluidic designs. Microchannel R(elec) was shown to dynamically mimic pressure waveforms applied to a membrane in a variable microfluidic resistor. The variable resistor was then used to dynamically control aqueous-in-oil droplet sizes and spacing, providing a unique and convenient control system for droplet-generating devices. This conductivity-based method for fluidic resistance measurement is thus a useful tool for static or real-time characterization of microfluidic systems. Copyright © 2012 Elsevier B.V. All rights reserved.

A four-probe thermal transport measurement method for nanostructures

Energy Technology Data Exchange (ETDEWEB)

Kim, Jaehyun; Ou, Eric; Sellan, Daniel P.; Shi, Li, E-mail: lishi@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States)

2015-04-15

Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models.

A four-probe thermal transport measurement method for nanostructures

International Nuclear Information System (INIS)

Kim, Jaehyun; Ou, Eric; Sellan, Daniel P.; Shi, Li

2015-01-01

Several experimental techniques reported in recent years have enabled the measurement of thermal transport properties of nanostructures. However, eliminating the contact thermal resistance error from the measurement results has remained a critical challenge. Here, we report a different four-probe measurement method that can separately obtain both the intrinsic thermal conductance and the contact thermal resistance of individual nanostructures. The measurement device consists of four microfabricated, suspended metal lines that act as resistive heaters and thermometers, across which the nanostructure sample is assembled. The method takes advantage of the variation in the heat flow along the suspended nanostructure and across its contacts to the four suspended heater and thermometer lines, and uses sixteen sets of temperature and heat flow measurements to obtain nine of the thermal resistances in the measurement device and the nanostructure sample, including the intrinsic thermal resistance and the two contact thermal resistances to the middle suspended segment of the nanostructure. Two single crystalline Si nanowires with different cross sections are measured in this work to demonstrate the effectiveness of the method. This four-probe thermal transport measurement method can lead to future discoveries of unique size-dependent thermal transport phenomena in nanostructures and low-dimensional materials, in addition to providing reliable experimental data for calibrating theoretical models

Noncontact sheet resistance measurement technique for wafer inspection

Science.gov (United States)

Kempa, Krzysztof; Rommel, J. Martin; Litovsky, Roman; Becla, Peter; Lojek, Bohumil; Bryson, Frank; Blake, Julian

1995-12-01

A new technique, MICROTHERM, has been developed for noncontact sheet resistance measurements of semiconductor wafers. It is based on the application of microwave energy to the wafer, and simultaneous detection of the infrared radiation resulting from ohmic heating. The pattern of the emitted radiation corresponds to the sheet resistance distribution across the wafer. This method is nondestructive, noncontact, and allows for measurements of very small areas (several square microns) of the wafer.

Resistivity Correction Factor for the Four-Probe Method: Experiment I

Science.gov (United States)

Yamashita, Masato; Yamaguchi, Shoji; Enjoji, Hideo

1988-05-01

Experimental verification of the theoretically derived resistivity correction factor (RCF) is presented. Resistivity and sheet resistance measurements by the four-probe method are made on three samples: isotropic graphite, ITO film and Au film. It is indicated that the RCF can correct the apparent variations of experimental data to yield reasonable resistivities and sheet resistances.

Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement

Science.gov (United States)

Kikta, Thomas J.; Mitchell, Ronald D.

1992-01-01

A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet.

Plethysmographic measurements of specific airway resistance in young children

DEFF Research Database (Denmark)

Bisgaard, Hans; Nielsen, Kim G

2005-01-01

allowed discrimination of young children with respiratory disease. Bronchial hyperresponsiveness can be determined with acceptable short-term and long-term repeatability and provides good discrimination between asthmatics and healthy young children. The effects of the major antiasthmatic therapies have......Validated methods for lung function measurements in young children are lacking. Plethysmographic measurement of specific airway resistance (sRaw) provides such a method applicable from 2 years of age. sRaw gauges airway resistance from the measurements of the pressure changes driving the airflow...... during tidal breathing. These measurements require no active cooperation and are therefore feasible in children from 2 years of age. The within-observer and between-observer variability of sRaw in young children compare favorably with alternative methods. Reference values are available for sRaw and have...

A TECHNIQUE OF MEASURING OF RESISTANCE OF A GROUNDING DEVICE

Directory of Open Access Journals (Sweden)

I.V. Nizhevskyi

2016-06-01

Full Text Available Introduction. Measurement of resistance of the grounding device (GD by means of a three-electrode system. This requires not only the right choice of installation locations of measuring electrodes, but also the determination of the point of zero potential. Implementation of these requirements quite time-consuming, and in some cases impossible. Aim. Develop a new technique for measuring the electrical resistance of the GD. Task. The method of measuring the resistance of the GD with the help of a three-electrode setup is necessary to exclude the determination of the point of zero potential. Method. Mathematical modeling and calculation engine. Results. A three-electrode system for measuring the resistance of grounding devices (GD for various purposes is considered. On the basis of Maxwell equations a theoretical substantiation of a new technique for measuring the resistance of any GD of any construction in random soil structure has been proposed. An equation system of the sixth order has been obtained, its solution makes it possible to measure its own mutual resistance in the three-electrode installation with sufficiently high accuracy. Peculiarities of drawing up a calculation scheme of substitution of a three-electrode installation with lumped parameters: self and mutual impedance. Use of the principle of reciprocity eliminates the need of finding a point of zero potential which is a rather difficult task. The technique allows to minimize the spacing of measuring electrodes outside the GD, which substantially reduces the length of wiring of the measurement circuit and increases the «signal-to-interference» ratio and also removes the restrictions on the development of the territory outside the GD being tested. Conclusion. The procedure allows to evaluate the self and mutual impedance grounding all the electrodes in a three-electrode measuring installation of the grounding resistance of the device without finding the point of zero potential.

A passive quantitative measurement of airway resistance using depth data.

Science.gov (United States)

Ostadabbas, Sarah; Bulach, Christoph; Ku, David N; Anderson, Larry J; Ghovanloo, Maysam

2014-01-01

The Respiratory Syncytial Virus (RSV) is the most common cause of serious lower respiratory tract infections in infants and young children. RSV often causes increased airway resistance, clinically detected as wheezing by chest auscultation. In this disease, expiratory flows are significantly reduced due to the high resistance in patient's airway passages. A quantitative method for measuring resistance can have a great benefit to diagnosis and management of children with RSV infections as well as with other lung diseases. Airway resistance is defined as the lung pressure divided by the airflow. In this paper, we propose a method to quantify resistance through a simple, non-contact measurement of chest volume that can act as a surrogate measure of the lung pressure and volumetric airflow. We used depth data collected by a Microsoft Kinect camera for the measurement of the lung volume over time. In our experimentation, breathing through a number of plastic straws induced different airway resistances. For a standard spirometry test, our volume/flow estimation using Kinect showed strong correlation with the flow data collected by a commercially-available spirometer (five subjects, each performing 20 breathing trials, correlation coefficient = 0.88, with 95% confidence interval). As the number of straws decreased, emulating a higher airway obstruction, our algorithm was sufficient to distinguish between several levels of airway resistance.

Electromigration early resistance increase measurements

NARCIS (Netherlands)

Niehof, J.; Flinn, P.A.; Maloney, T.J.

1993-01-01

An early resistance change measurement set-up, using an AC bridge technique, has been developed, and measurements have been performed. Large sample-to-sample variations occur. The characteristic time for the resistance change curve is shorter for resistance increase (under current stress) than for

Electrical resistivity measurements to predict abrasion resistance

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 31; Issue 2. Electrical resistivity measurements to predict abrasion resistance of rock aggregates ... It was seen that correlation coefficients were increased for the rock classes. In addition ...

Proposed Modifications to Engineering Design Guidelines Related to Resistivity Measurements and Spacecraft Charging

Science.gov (United States)

Dennison, J. R.; Swaminathan, Prasanna; Jost, Randy; Brunson, Jerilyn; Green, Nelson; Frederickson, A. Robb

2005-01-01

A key parameter in modeling differential spacecraft charging is the resistivity of insulating materials. This determines how charge will accumulate and redistribute across the spacecraft, as well as the time scale for charge transport and dissipation. Existing spacecraft charging guidelines recommend use of tests and imported resistivity data from handbooks that are based principally upon ASTM methods that are more applicable to classical ground conditions and designed for problems associated with power loss through the dielectric, than for how long charge can be stored on an insulator. These data have been found to underestimate charging effects by one to four orders of magnitude for spacecraft charging applications. A review is presented of methods to measure the resistive of highly insulating materials, including the electrometer-resistance method, the electrometer-constant voltage method, the voltage rate-of-change method and the charge storage method. This is based on joint experimental studies conducted at NASA Jet Propulsion Laboratory and Utah State University to investigate the charge storage method and its relation to spacecraft charging. The different methods are found to be appropriate for different resistivity ranges and for different charging circumstances. A simple physics-based model of these methods allows separation of the polarization current and dark current components from long duration measurements of resistivity over day- to month-long time scales. Model parameters are directly related to the magnitude of charge transfer and storage and the rate of charge transport. The model largely explains the observed differences in resistivity found using the different methods and provides a framework for recommendations for the appropriate test method for spacecraft materials with different resistivities and applications. The proposed changes to the existing engineering guidelines are intended to provide design engineers more appropriate methods for

Evaluation of metal–nanowire electrical contacts by measuring contact end resistance

International Nuclear Information System (INIS)

Park, Hongsik; Beresford, Roderic; Xu, Jimmy; Ha, Ryong; Choi, Heon-Jin; Shin, Hyunjung

2012-01-01

It is known, but often unappreciated, that the performance of nanowire (NW)-based electrical devices can be significantly affected by electrical contacts between electrodes and NWs, sometimes to the extent that it is really the contacts that determine the performance. To correctly understand and design NW device operation, it is thus important to carefully measure the contact resistance and evaluate the contact parameters, specific contact resistance and transfer length. A four-terminal pattern or a transmission line model (TLM) pattern has been widely used to measure contact resistance of NW devices and the TLM has been typically used to extract contact parameters of NW devices. However, the conventional method assumes that the electrical properties of semiconducting NW regions covered by a metal are not changed after electrode formation. In this study, we report that the conventional methods for contact evaluation can give rise to considerable errors because of an altered property of the NW under the electrodes. We demonstrate that more correct contact resistance can be measured from the TLM pattern rather than the four-terminal pattern and correct contact parameters including the effects of changed NW properties under electrodes can be evaluated by using the contact end resistance measurement method. (paper)

Method for measuring the resistive transition and critical current in superconductors using pulsed current

International Nuclear Information System (INIS)

McGinnis, W.C.; Jones, T.E.

1993-01-01

A method is described for measuring the intragranular critical current of a granular superconductive material, comprising the steps of: conducting a substantially rectangular electronic pulse through said material so as to conduct a current through said material such that when said intragranular critical current of said material is exceeded, any grains present in said material are in a superconducting state when said current is less than said intragranular critical current, said material having a critical temperature; measuring said current through said material while conducting said pulse; measuring a voltage difference across said material while conducting said pulse; and determining said intragranular critical current through said material by varying said current to discern a current level at which an electrical resistance of said material increases to that of a non-superconducting state as the grains of said material transition from said superconducting to said non-superconducting state

Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils

Science.gov (United States)

Kilic, Veli Tayfun; Unal, Emre; Demir, Hilmi Volkan

2017-05-01

In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil's inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel's presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel's presence and powering on only the coils that are loaded by the vessel with predetermined current levels.

The Dutch Measure for quantification of Treatment Resistance in Depression (DM-TRD) : an extension of the Maudsley Staging Method

NARCIS (Netherlands)

Peeters, Frenk P. M. L.; Ruhe, Henricus G.; Wichers, Marieke; Abidi, Latifa; Kaub, Karin; van der Lande, H. Josephine; Spijker, Jan; Huibers, Marcus J. H.; Schene, Aart H.

2016-01-01

Background: Treatment resistant depression (TRD) is common in daily practice. An empirical, widely accepted and applicable measure to quantify TRD is lacking. Previously, the Maudsley Staging Method (MSM) showed good validity. We aimed to improve the MSM by refining and extending its items resulting

Surface Resistance Measurements of LHC Dipole Beam Screen Samples

CERN Document Server

Caspers, Friedhelm; Ruggiero, F; Tan, J; Tsutsui, H

2000-01-01

An estimate of the resistive losses in the LHC dipole beam screen is given from cold surface resistance measurements using the shielded pair technique. Several beam screen samples have been evaluated, with different copper coating methods, including a sample with ribbed surface envisaged to reduce electron cloud losses thanks to its low reflectivity. Experimental data, derived by a proper analysis of the measured Q-factors and including error estimates are compared with theoretical predictions of the anomalous skin effect.

Online junction temperature measurement via internal gate resistance during turn-on

DEFF Research Database (Denmark)

Baker, Nick; Munk-Nielsen, Stig; Liserre, Marco

2014-01-01

A new method for junction temperature measurement of power semiconductor switches is presented. The measurement exploits the temperature dependent resistance of the temperature sensitive electrical parameter (TSEP): the internal gate resistance. This dependence can be observed during the normal...... switching transitions of an IGBT or MOSFET, and as a result the presented method uses the integral of the gate voltage during the turn-on delay. A measurement circuit can be integrated into a gate driver with no modification to converter or gate driver operation and holds significant advantages over other...

A new capacitive/resistive probe method for studying magnetic surfaces

International Nuclear Information System (INIS)

Kitajima, Sumio; Takayama, Masakazu; Zama, Tatsuya; Takaya, Kazuhiro; Takeuchi, Nobunao; Watanabe, Hiroshige

1991-01-01

A new capacitive/resistive probe method for mapping the magnetic surfaces from resistance or capacitance between a magnetic surface and a vacuum vessel was developed and tested. Those resistances and capacitances can be regarded as components of a simple electrical bridge circuit. This method exploits electrical transient response of the bridge circuit for a square pulse. From equiresistance or equicapacitance points, the magnetic surface structure can be deduced. Measurements on the Tohoku University Heliac, which is a small-size standard heliac, show good agreement with numerical calculations. This method is particularly useful for pulse-operated machines. (author)

Seven methods to measure ground moisture

International Nuclear Information System (INIS)

Anon.

1983-01-01

The correct irrigation methods are of great importance to the deciduous fruit grower. The article discusses seven methods for the measuring of ground humidity. These methods are based on gravimetry, electric resistance, gamma attenuation, neutron humidity measurement, tensiometers and a study of the correlation between ground humidity and water evaporation. At this stage, the last technique is regarded as the most practicle method. Neutron moisture gages might be used if adhered to the regulations of NUCOR

Standard test method for galling resistance of material couples

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This test method covers a laboratory test that ranks the galling resistance of material couples using a quantitative measure. Bare metals, alloys, nonmetallic materials, coatings, and surface modified materials may be evaluated by this test method. 1.2 This test method is not designed for evaluating the galling resistance of material couples sliding under lubricated conditions, because galling usually will not occur under lubricated sliding conditions using this test method. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Burrowing as a novel voluntary strength training method for mice: A comparison of various voluntary strength or resistance exercise methods.

Science.gov (United States)

Roemers, P; Mazzola, P N; De Deyn, P P; Bossers, W J; van Heuvelen, M J G; van der Zee, E A

2018-04-15

Voluntary strength training methods for rodents are necessary to investigate the effects of strength training on cognition and the brain. However, few voluntary methods are available. The current study tested functional and muscular effects of two novel voluntary strength training methods, burrowing (digging a substrate out of a tube) and unloaded tower climbing, in male C57Bl6 mice. To compare these two novel methods with existing exercise methods, resistance running and (non-resistance) running were included. Motor coordination, grip strength and muscle fatigue were measured at baseline, halfway through and near the end of a fourteen week exercise intervention. Endurance was measured by an incremental treadmill test after twelve weeks. Both burrowing and resistance running improved forelimb grip strength as compared to controls. Running and resistance running increased endurance in the treadmill test and improved motor skills as measured by the balance beam test. Post-mortem tissue analyses revealed that running and resistance running induced Soleus muscle hypertrophy and reduced epididymal fat mass. Tower climbing elicited no functional or muscular changes. As a voluntary strength exercise method, burrowing avoids the confounding effects of stress and positive reinforcers elicited in forced strength exercise methods. Compared to voluntary resistance running, burrowing likely reduces the contribution of aerobic exercise components. Burrowing qualifies as a suitable voluntary strength training method in mice. Furthermore, resistance running shares features of strength training and endurance (aerobic) exercise and should be considered a multi-modal aerobic-strength exercise method in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

Apparatus for measuring resistance change only in a cell analyzer and method for calibrating it

Science.gov (United States)

Hoffman, Robert A.

1980-01-01

The disclosure relates to resistance only monitoring and calibration in an electrical cell analyzer. Sample and sheath fluid flows of different salinities are utilized, the sample flow being diameter modulated to produce a selected pattern which is compared to the resistance measured across the flows.

Diffusivity and electrical resistivity measurements in rock matrix around fractures

International Nuclear Information System (INIS)

Kumpulainen, H.; Uusheimo, K.

1989-12-01

Microfracturing of rock matrix around permeable fractures was studied experimentally from drill core samples around major fractures. The methods used were diffusion measurements using a 36 Cl-tracer and electrical resistivity measurements. Rock samples were from the Romuvaara investigation site, the granite specimen around a partially filled carbonate fracture (KR4/333 m) and gneiss specimen around a slickenside fracture (KR1/645 m). A consistent difference of one to two orders of magnitude in the levels of the methods with regard to the effective diffusion coefficients for Cl - -ion was found, the electrical resistivity measurement giving higher values. On the basis of the diffusion measurements the diffusion porosities could be calculated but these remained one to two orders of magnitude lower than that expected for granitic rocks using the water saturation method. A possible reason for these differences could have been the low, in some cases 0.004 M NaC1-concentration in the diffusion experiments vs. the 1 M NaCl-concentration used in the electrical resistivity measurements. Due to the small number of specimens and cross sectional areas of only 2 cm 2 , rock inhomogeneity effects were significant making the interpretation of the results somewhat troublesome. Porosities on fracture surfaces seemed to be higher than in the deeper, more intact rock matrix

Development of Ultrafast Laser Flash Methods for Measuring Thermophysical Properties of Thin Films and Boundary Thermal Resistances

Science.gov (United States)

Baba, Tetsuya; Taketoshi, Naoyuki; Yagi, Takashi

2011-11-01

Reliable thermophysical property values of thin films are important to develop advanced industrial technologies such as highly integrated electronic devices, phase-change memories, magneto-optical disks, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), semiconductor lasers (LDs), flat-panel displays, and power electronic devices. In order to meet these requirements, the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has developed ultrafast laser flash methods heated by picosecond pulse or nanosecond pulse with the same geometrical configuration as the laser flash method, which is the standard method to measure the thermal diffusivity of bulk materials. Since these pulsed light heating methods induce one-dimensional heat diffusion across a well-defined length of the specimen thickness, the absolute value of thermal diffusivity across thin films can be measured reliably. Using these ultrafast laser flash methods, the thermal diffusivity of each layer of multilayered thin films and the boundary thermal resistance between the layers can be determined from the observed transient temperature curves based on the response function method. The thermophysical properties of various thin films important for modern industries such as the transparent conductive films used for flat-panel displays, hard coating films, and multilayered films of next-generation phase-change optical disks have been measured by these methods.

Methods for quantifying adipose tissue insulin resistance in overweight/obese humans.

Science.gov (United States)

Ter Horst, K W; van Galen, K A; Gilijamse, P W; Hartstra, A V; de Groot, P F; van der Valk, F M; Ackermans, M T; Nieuwdorp, M; Romijn, J A; Serlie, M J

2017-08-01

Insulin resistance of adipose tissue is an important feature of obesity-related metabolic disease. However, assessment of lipolysis in humans requires labor-intensive and expensive methods, and there is limited validation of simplified measurement methods. We aimed to validate simplified methods for the quantification of adipose tissue insulin resistance against the assessment of insulin sensitivity of lipolysis suppression during hyperinsulinemic-euglycemic clamp studies. We assessed the insulin-mediated suppression of lipolysis by tracer-dilution of [1,1,2,3,3- 2 H 5 ]glycerol during hyperinsulinemic-euglycemic clamp studies in 125 overweight or obese adults (85 men, 40 women; age 50±11 years; body mass index 38±7 kg m -2 ). Seven indices of adipose tissue insulin resistance were validated against the reference measurement method. Low-dose insulin infusion resulted in suppression of the glycerol rate of appearance ranging from 4% (most resistant) to 85% (most sensitive), indicating a good range of adipose tissue insulin sensitivity in the study population. The reference method correlated with (1) insulin-mediated suppression of plasma glycerol concentrations (r=0.960, PInsulin Resistance (Adipo-IR) index (fasting plasma insulin-NEFA product; r=-0.526, Pinsulin-glycerol product (r=-0.467, PInsulin Resistance Index (fasting plasma insulin-basal lipolysis product; r=0.460, PInsulin Sensitivity Check Index (QUICKI)-NEFA index (r=0.621, Pinsulin resistance (area under the curve ⩾0.801, Pinsulin sensitivity (that is, the antilipolytic action of insulin) can be reliably quantified in overweight and obese humans by simplified index methods. The sensitivity and specificity of the Adipo-IR index and the fasting plasma insulin-glycerol product, combined with their simplicity and acceptable agreement, suggest that these may be most useful in clinical practice.

Mathematical modeling for corrosion environment estimation based on concrete resistivity measurement directly above reinforcement

International Nuclear Information System (INIS)

Lim, Young-Chul; Lee, Han-Seung; Noguchi, Takafumi

2009-01-01

This study aims to formulate a resistivity model whereby the concrete resistivity expressing the environment of steel reinforcement can be directly estimated and evaluated based on measurement immediately above reinforcement as a method of evaluating corrosion deterioration in reinforced concrete structures. It also aims to provide a theoretical ground for the feasibility of durability evaluation by electric non-destructive techniques with no need for chipping of cover concrete. This Resistivity Estimation Model (REM), which is a mathematical model using the mirror method, combines conventional four-electrode measurement of resistivity with geometric parameters including cover depth, bar diameter, and electrode intervals. This model was verified by estimation using this model at areas directly above reinforcement and resistivity measurement at areas unaffected by reinforcement in regard to the assessment of the concrete resistivity. Both results strongly correlated, proving the validity of this model. It is expected to be applicable to laboratory study and field diagnosis regarding reinforcement corrosion. (author)

The effect of electrode contact resistance and capacitive coupling on Complex Resistivity measurements

DEFF Research Database (Denmark)

Ingeman-Nielsen, Thomas

2006-01-01

The effect of electrode contact resistance and capacitive coupling on complex resistivity (CR) measurements is studied in this paper. An equivalent circuit model for the receiver is developed to describe the effects. The model shows that CR measurements are severely affected even at relatively lo...... with the contact resistance artificially increased by resistors. The results emphasize the importance of keeping contact resistance low in CR measurements....

Measuring electric conductivity in liquid metals by eddy current method

International Nuclear Information System (INIS)

Zhuravlev, S.P.; Ostrovskij, O.I.; Grigoryan, V.A.

1982-01-01

Technique permitting to apply the method of vertiginous currents for investigation of electric conductivity of metal melts in the high temperature range is presented. Interferences affecting accuracy of measurements are specified and ways of their removing are pointed out. Scheme of measuring and design of the facility are described. Results of measuring electric resistance of liquid Fe, Co, Ni obtained for the first time by this method are presented. The data obtained agree with the results of measurements conducted by the method of the rotating magnetic field. Difference in absolute values of electric resistance in parallel experiments for each metal does not exceed 4%

Comparative study of on-line response time measurement methods for platinum resistance thermometer

International Nuclear Information System (INIS)

Zwingelstein, G.; Gopal, R.

1979-01-01

This study deals with the in site determination of the response time of platinum resistance sensor. In the first part of this work, two methods furnishing the reference response time of the sensors are studied. In the second part of the work, two methods obtaining the response time without dismounting of the sensor, are studied. A comparative study of the performances of these methods is included for fluid velocities varying from 0 to 10 m/sec, in both laboratory and plant conditions

Self-Diagnosis of Damage in Carbon Fiber Reinforced Composites Using Electrical Residual Resistance Measurement

Energy Technology Data Exchange (ETDEWEB)

Kang, Ji Ho [KAERI, Daejeon (Korea, Republic of)

2009-08-15

The objective of this research was to develop a practical integrated approach using extracted features from electrical resistance measurements and coupled electromechanical models of damage, for in-situ damage detection and sensing in carbon fiber reinforced plastic(CFRP) composites. To achieve this objective, we introduced specific known damage (in terms of type, size, and location) into CFRP laminates and established quantitative relationships with the electrical resistance measurements. For processing of numerous measurement data, an autonomous data acquisition system was devised. We also established a specimen preparation procedure and a method for electrode setup. Coupon and panel CFRP laminate specimens with several known damage were tested. Coupon specimens with various sizes of artificial delaminations obtained by inserting Teflon film were manufactured and the resistance was measured. The measurement results showed that increase of delamination size led to increase of resistance implying that it is possible to sense the existence and size of delamination. A quasi-isotropic panel was manufactured and electrical resistance was measured. Then three different sizes of holes were drilled at a chosen location. The panel was prepared using the established procedures with six electrode connections on each side making a total of twenty-four electrodes. Vertical, horizontal, and diagonal pairs of electrodes were chosen and the resistance was measured. The measurement results showed the possibility of the established measurement system for an in-situ damage detection method for CFRP composite structures.

Rolling Resistance Measurement and Model Development

DEFF Research Database (Denmark)

Andersen, Lasse Grinderslev; Larsen, Jesper; Fraser, Elsje Sophia

2015-01-01

There is an increased focus worldwide on understanding and modeling rolling resistance because reducing the rolling resistance by just a few percent will lead to substantial energy savings. This paper reviews the state of the art of rolling resistance research, focusing on measuring techniques, s......, surface and texture modeling, contact models, tire models, and macro-modeling of rolling resistance...

Application of column tests and electrical resistivity methods for leachate transport monitoring

Directory of Open Access Journals (Sweden)

Wychowaniak Dorota

2015-09-01

Full Text Available Development of the human civilization leads to the pollution of environment. One of the contamination which are a real threat to soil and groundwater are leachates from landfills. In this paper the solute transport through soil was considered. For this purpose, the laboratory column tests of chlorides tracer and leachates transport on two soil samples have been carried out. Furthermore, the electrical resistivity method was applied as auxiliary tool to follow the movements of solute through the soil column what allowed to compare between the results obtained with column test method and electrical resistivity measurements. Breakthrough curves obtained by conductivity and resistivity methods represents similar trends which leads to the conclusion about the suitability of electrical resistivity methods for contamination transport monitoring in soil-water systems.

Slip resistance of winter footwear on snow and ice measured using maximum achievable incline.

Science.gov (United States)

Hsu, Jennifer; Shaw, Robert; Novak, Alison; Li, Yue; Ormerod, Marcus; Newton, Rita; Dutta, Tilak; Fernie, Geoff

2016-05-01

Protective footwear is necessary for preventing injurious slips and falls in winter conditions. Valid methods for assessing footwear slip resistance on winter surfaces are needed in order to evaluate footwear and outsole designs. The purpose of this study was to utilise a method of testing winter footwear that was ecologically valid in terms of involving actual human testers walking on realistic winter surfaces to produce objective measures of slip resistance. During the experiment, eight participants tested six styles of footwear on wet ice, on dry ice, and on dry ice after walking over soft snow. Slip resistance was measured by determining the maximum incline angles participants were able to walk up and down in each footwear-surface combination. The results indicated that testing on a variety of surfaces is necessary for establishing winter footwear performance and that standard mechanical bench tests for footwear slip resistance do not adequately reflect actual performance. Practitioner Summary: Existing standardised methods for measuring footwear slip resistance lack validation on winter surfaces. By determining the maximum inclines participants could walk up and down slopes of wet ice, dry ice, and ice with snow, in a range of footwear, an ecologically valid test for measuring winter footwear performance was established.

Root resistance to cavitation is accurately measured using a centrifuge technique.

Science.gov (United States)

Pratt, R B; MacKinnon, E D; Venturas, M D; Crous, C J; Jacobsen, A L

2015-02-01

Plants transport water under negative pressure and this makes their xylem vulnerable to cavitation. Among plant organs, root xylem is often highly vulnerable to cavitation due to water stress. The use of centrifuge methods to study organs, such as roots, that have long vessels are hypothesized to produce erroneous estimates of cavitation resistance due to the presence of open vessels through measured samples. The assumption that roots have long vessels may be premature since data for root vessel length are sparse; moreover, recent studies have not supported the existence of a long-vessel artifact for stems when a standard centrifuge technique was used. We examined resistance to cavitation estimated using a standard centrifuge technique and compared these values with native embolism measurements for roots of seven woody species grown in a common garden. For one species we also measured vulnerability using single-vessel air injection. We found excellent agreement between root native embolism and the levels of embolism measured using a centrifuge technique, and with air-seeding estimates from single-vessel injection. Estimates of cavitation resistance measured from centrifuge curves were biologically meaningful and were correlated with field minimum water potentials, vessel diameter (VD), maximum xylem-specific conductivity (Ksmax) and vessel length. Roots did not have unusually long vessels compared with stems; moreover, root vessel length was not correlated to VD or to the vessel length of stems. These results suggest that root cavitation resistance can be accurately and efficiently measured using a standard centrifuge method and that roots are highly vulnerable to cavitation. The role of root cavitation resistance in determining drought tolerance of woody species deserves further study, particularly in the context of climate change. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Test methods for on site measurement of resistivity of concrete. A RILEM TC-154 Technical Recommendation

NARCIS (Netherlands)

Polder, R.B.

2000-01-01

This paper describes methods to assess concrete resistivity on site for various purposes related to corrosion and protection of reinforcement. It is based on a first draft of a RILEM Technical Recommendation. The electrical resistivity of concrete can be related to the two processes involved in

Surface resistivity measurement of plasma treated polymers

International Nuclear Information System (INIS)

Simon, D.; Pigram, P.J.; Liesegang, J.

2000-01-01

Full text: Resistivity of insulators is an important property of materials used within the integrated circuit and packaging industries. The measurement of electrical resistivity of insulator materials in the surface region in this work is interpreted through observations of surface charge decay. A self-field driven and diffusion charge transport theory is used to model the process and resistivity values obtained computationally. Data for the charge decay of surface charged samples are collected by suspending them inside a coaxial cylinder connected to an electrometer. Samples used have been low density polyethylene LDPE sheet, both pristine and surface treated. Some samples have been treated by air plasma at low vacuum pressures for different periods of time; others have been washed in ethyl acetate and then plasma treated before the resistivity measurement. The sets of resistivity measurements form the various treatments are compared below. X-ray photoelectron spectroscopy (XPS) has also been used to investigate and account for the observed variations in surface resistivity

A Method for testing the integrated thermal resistance of thermoelectric modules

Science.gov (United States)

Gao, Junling; Du, Qungui; Chen, Min

2013-11-01

The integrated thermal resistance (ITR) of thermoelectric modules (TEMs) is an important parameter that represents the thermal-conduction of ceramic substrates, copper conducting strips, and welding material used in the TEM as well as the thermal contact resistances between different materials. In this study, an accurate and practical test method is proposed for the ITR of TEMs according to thermoelectric heat transfer theory and the equivalent characteristics of heat flux through the cold and hot sides of TEMs in an open-circuit situation. By using such measurements and comparisons, it is verified that the measured ITR value in our mode is accurate and reliable. In particular this method accurately predicts the actual operating conditions of TEMs, in which TEMs are under certain mechanical pressure. It effectively solves the problem of thermal resistance extraction from operating TEMs and is of great significance in their analysis and optimization.

Estimation of the flow resistances exerted in coronary arteries using a vessel length-based method.

Science.gov (United States)

Lee, Kyung Eun; Kwon, Soon-Sung; Ji, Yoon Cheol; Shin, Eun-Seok; Choi, Jin-Ho; Kim, Sung Joon; Shim, Eun Bo

2016-08-01

Flow resistances exerted in the coronary arteries are the key parameters for the image-based computer simulation of coronary hemodynamics. The resistances depend on the anatomical characteristics of the coronary system. A simple and reliable estimation of the resistances is a compulsory procedure to compute the fractional flow reserve (FFR) of stenosed coronary arteries, an important clinical index of coronary artery disease. The cardiac muscle volume reconstructed from computed tomography (CT) images has been used to assess the resistance of the feeding coronary artery (muscle volume-based method). In this study, we estimate the flow resistances exerted in coronary arteries by using a novel method. Based on a physiological observation that longer coronary arteries have more daughter branches feeding a larger mass of cardiac muscle, the method measures the vessel lengths from coronary angiogram or CT images (vessel length-based method) and predicts the coronary flow resistances. The underlying equations are derived from the physiological relation among flow rate, resistance, and vessel length. To validate the present estimation method, we calculate the coronary flow division over coronary major arteries for 50 patients using the vessel length-based method as well as the muscle volume-based one. These results are compared with the direct measurements in a clinical study. Further proving the usefulness of the present method, we compute the coronary FFR from the images of optical coherence tomography.

Calculation of skid resistance from texture measurements

Directory of Open Access Journals (Sweden)

Andreas Ueckermann

2015-02-01

Full Text Available There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface. Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer. Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors like water film thickness, temperature, measurement speed, rubber aging, rubber wear and even road evenness and curviness. All of these factors will affect the skid resistance and are difficult to control. We present a concept of contactless skid resistance measurement which is based on optical texture measurement and consists of two components: measurement of the pavement texture by means of an optical measuring system and calculation of the skid resistance based on the measured texture by means of a rubber friction model. The basic assumptions underlying the theoretical approach and the model itself based on the theory of Persson are presented. The concept is applied to a laboratory device called Wehner/Schulze (W/S machine to prove the theoretical approach. The results are very promising. A strong indication could be provided that skid resistance could be measured without contact in the future.

Application of thermo-electromotive force and electric resistance measuring methods to researching phase transformations in Zr1Nb alloy

International Nuclear Information System (INIS)

Klimenko, S.P.; Gritsina, V.M.; Petel'guzov, I.A.; Chernyaeva, T.P.

2007-01-01

The paper determines the applicability areas of different methods for the study of structural phase transformations in a Zr+1Nb alloy, which is extensively used in reactor construction; production and fabrication of products from Zr+1Nb is currently developed in Ukraine. Electromotive force and electric resistance were measured to study structural phase transformations of Zr+1Nb fuel rod tubes based on calciumthermal zirconium (Zr1Nb). It was established that changes in electric resistance clearly show the beginning of a massive α → β transition at ∼ 750 degree C and the end of α → β transition at ∼ 950 degree C, whereas measurement of thermo-e.m.f. in the samples subjected to successive 3-hour step annealing in the temperature range from 300 to 700 degree C allows the temperature of monotectoid transformation to be found. For sample Zr1Nb batches the temperature of monotectoid transformation is (620±7) degree C. The measurement results are consistent with the similar studies carried out on Zr+1Nb fuel rod tubes based on electrolytic zirconium (E110), for which the temperature of monotectoid transformation is equal to ∼ 610 degree C

Leaching of Conductive Species: Implications to Measurements of Electrical Resistivity.

Science.gov (United States)

Spragg, R; Jones, S; Bu, Y; Lu, Y; Bentz, D; Snyder, K; Weiss, J

2017-05-01

Electrical tests have been used to characterize the microstructure of porous materials, the measured electrical response being determined by the contribution of the microstructure (porosity and tortuosity) and the electrical properties of the solution (conductivity of the pore solution) inside the pores of the material. This study has shown how differences in concentration between the pore solution (i.e., the solution in the pores) and the storage solution surrounding the test specimen leads to significant transport (leaching) of the conductive ionic species between the pore solution and the storage solution. Leaching influences the resistivity of the pore solution, thereby influencing electrical measurements on the bulk material from either a surface or uniaxial bulk resistance test. This paper has three main conclusions: 1.) Leaching of conductive species does occur with concentration gradients and that a diffusion based approach can be used to estimate the time scale associated with this change. 2.) Leaching of ions in the pore solution can influence resistivity measurements, and the ratio of surface to uniaxial resistivity can be used as a method to assess the presence of leaching and 3.) An estimation of the magnitude of leaching for standardized tests of cementitious materials.

Method of separate determination of high-ohmic sample resistance and contact resistance

Directory of Open Access Journals (Sweden)

Vadim A. Golubiatnikov

2015-09-01

Full Text Available A method of separate determination of two-pole sample volume resistance and contact resistance is suggested. The method is applicable to high-ohmic semiconductor samples: semi-insulating gallium arsenide, detector cadmium-zinc telluride (CZT, etc. The method is based on near-contact region illumination by monochromatic radiation of variable intensity from light emitting diodes with quantum energies exceeding the band gap of the material. It is necessary to obtain sample photo-current dependence upon light emitting diode current and to find the linear portion of this dependence. Extrapolation of this linear portion to the Y-axis gives the cut-off current. As the bias voltage is known, it is easy to calculate sample volume resistance. Then, using dark current value, one can determine the total contact resistance. The method was tested for n-type semi-insulating GaAs. The contact resistance value was shown to be approximately equal to the sample volume resistance. Thus, the influence of contacts must be taken into account when electrophysical data are analyzed.

Latest groundwater investigating methods and measuring techniques. 1. ; Investigation on aquifer distribution (investigation method). Saikin no chikasui chosa hoho to keisoku gijutsu. 1. ; Taisuiso no bunpu chosa (tansaho)

Energy Technology Data Exchange (ETDEWEB)

Yamai, T [Asia Air Survey Co. Ltd., Tokyo (Japan)

1993-06-30

This paper explains groundwater investigating methods, introducing particularly two methods. The resistivity tomography is a method to measure potential distribution generated when current is applied around an area to be investigated. Using the measurement result as projection data, the resistivity distribution is restructured within the area of the investigation. The paper summarizes the measurement method (measuring equipment, electrode arrangement, etc.), the analytic method (establishment of an initial model, and the alpha-center method to calculate theoretical potentials corresponding to the model), and an application example of the method in which the resistivity change was observed using permeation of salt tracers. The resistivity imaging method (two-dimensional resistivity analysis method) is superior in practicability to the above method under the present state of the art. This method does not differ from the conventional resistivity method in methodology, but improves the analytic accuracy over the conventional electrical investigation method as a result of analysis combining the simplified two-dimensional analysis method with the alpha-center method. A summary is given on the measuring and analyzing methods. 13 refs., 10 figs.

Evaluation of the measurement uncertainty when measuring the resistance of solid isolating materials to tracking

Science.gov (United States)

Stare, E.; Beges, G.; Drnovsek, J.

2006-07-01

This paper presents the results of research into the measurement of the resistance of solid isolating materials to tracking. Two types of tracking were investigated: the proof tracking index (PTI) and the comparative tracking index (CTI). Evaluation of the measurement uncertainty in a case study was performed using a test method in accordance with the IEC 60112 standard. In the scope of the tests performed here, this particular test method was used to ensure the safety of electrical appliances. According to the EN ISO/IEC 17025 standard (EN ISO/IEC 17025), in the process of conformity assessment, the evaluation of the measurement uncertainty of the test method should be carried out. In the present article, possible influential parameters that are in accordance with the third and fourth editions of the standard IEC 60112 are discussed. The differences, ambiguities or lack of guidance referring to both editions of the standard are described in the article 'Ambiguities in technical standards—case study IEC 60112—measuring the resistance of solid isolating materials to tracking' (submitted for publication). Several hundred measurements were taken in the present experiments in order to form the basis for the results and conclusions presented. A specific problem of the test (according to the IEC 60112 standard) is the great variety of influential physical parameters (mechanical, electrical, chemical, etc) that can affect the results. At the end of the present article therefore, there is a histogram containing information on the contributions to the measurement uncertainty.

Measurement by a cylinder test stand and tyre rolling resistance

Directory of Open Access Journals (Sweden)

A. Dávid

2006-03-01

Full Text Available Sometimes it is necessary to test how repair affects the properties of the car. These tests are carried out using a cylinder test stand. During the test the tyre is rolling between two cylinders of a small diameter. The question arises whether the rolling resistance of the tyre is the same as the rolling resistance when the wheel is rolling on the plane. If it is not the same what is the reliation between tyre resistances in these two cases? It is an important answer because the change of rolling resistance can affect consumption, the highest speed, engine power and other results of measurement. The paper gives the answer to these questions and describes the method of getting this information.

Electrical Resistivity Measurements: a Review

Science.gov (United States)

Singh, Yadunath

World-wide interest on the use of ceramic materials for aerospace and other advanced engineering applications, has led to the need for inspection techniques capable of detecting unusually electrical and thermal anomalies in these compounds. Modern ceramic materials offer many attractive physical, electrical and mechanical properties for a wide and rapidly growing range of industrial applications; moreover specific use may be made of their electrical resistance, chemical resistance, and thermal barrier properties. In this review, we report the development and various techniques for the resistivity measurement of solid kind of samples.

High-resolution resistivity measurements at the Down Ampney research site

International Nuclear Information System (INIS)

Hallam, J.R.; Jackson, P.D.; Rainsbury, M.P.; Raines, M.G.

1993-01-01

Reconnaissance geophysical surveying in the earlier stages of the project had mapped a previously unknown fault across the Down Ampney site, using a conventional resistivity profiling technique. The Schlumberger array, optimized for the local geological sequence, revealed a distinctive fault signature, characterized by a marked peak and a very steep gradient in each apparent resistivity profile. The most precise indicator for the fault locations was taken to be the mid-point of this steep gradient, which could be located with a tolerance of about ± 5 m. Subsequent consideration of the data acquisition and presentation method used in the apparent resistivity profiling techniques led to the conclusion that these methods were smoothing the electrical field response and thereby limiting the potential accuracy of fault location. To overcome this limitation a novel technique has been devised in which the potential field generated by an electric current flow is profiled directly in terms of resistance. With a measurement of resistance at each electrode position, no averaging or smoothing effect is introduced. This work is carried out under contract with the Commission of the European Communities, in the framework of its Research programme Management and radioactive waste disposal. 6 refs., 16 figs

On the Measurements of Numerical Viscosity and Resistivity in Eulerian MHD Codes

Energy Technology Data Exchange (ETDEWEB)

Rembiasz, Tomasz; Obergaulinger, Martin; Cerdá-Durán, Pablo; Aloy, Miguel-Ángel [Departamento de Astronomía y Astrofísica, Universidad de Valencia, C/Dr. Moliner 50, E-46100 Burjassot (Spain); Müller, Ewald, E-mail: tomasz.rembiasz@uv.es [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

2017-06-01

We propose a simple ansatz for estimating the value of the numerical resistivity and the numerical viscosity of any Eulerian MHD code. We test this ansatz with the help of simulations of the propagation of (magneto)sonic waves, Alfvén waves, and the tearing mode (TM) instability using the MHD code Aenus. By comparing the simulation results with analytical solutions of the resistive-viscous MHD equations and an empirical ansatz for the growth rate of TMs, we measure the numerical viscosity and resistivity of Aenus. The comparison shows that the fast magnetosonic speed and wavelength are the characteristic velocity and length, respectively, of the aforementioned (relatively simple) systems. We also determine the dependence of the numerical viscosity and resistivity on the time integration method, the spatial reconstruction scheme and (to a lesser extent) the Riemann solver employed in the simulations. From the measured results, we infer the numerical resolution (as a function of the spatial reconstruction method) required to properly resolve the growth and saturation level of the magnetic field amplified by the magnetorotational instability in the post-collapsed core of massive stars. Our results show that it is most advantageous to resort to ultra-high-order methods (e.g., the ninth-order monotonicity-preserving method) to tackle this problem properly, in particular, in three-dimensional simulations.

Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

Directory of Open Access Journals (Sweden)

Hans-Georg Schweiger

2010-06-01

Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

Decoupling pipeline influences in soil resistivity measurements with finite element techniques

Science.gov (United States)

Deo, R. N.; Azoor, R. M.; Zhang, C.; Kodikara, J. K.

2018-03-01

Periodic inspection of pipeline conditions is an important asset management strategy conducted by water and sewer utilities for efficient and economical operations of their assets in field. The Level 1 pipeline condition assessment involving resistivity profiling along the pipeline right-of-way is a common technique for delineating pipe sections that might be installed in highly corrosive soil environment. However, the technique can suffer from significant perturbations arising from the buried pipe itself, resulting in errors in native soil characterisation. To address this problem, a finite element model was developed to investigate the degree to which pipes of different a) diameters, b) burial depths, and c) surface conditions (bare or coated) can influence in-situ soil resistivity measurements using Wenner methods. It was found that the greatest errors can arise when conducting measurements over a bare pipe with the array aligned parallel to the pipe. Depending upon the pipe surface conditions, in-situ resistivity measurements can either be underestimated or overestimated from true soil resistivities. Following results based on simulations and decoupling equations, a guiding framework for removing pipe influences in soil resistivity measurements were developed that can be easily used to perform corrections on measurements. The equations require simple a-prior information on the pipe diameter, burial depth, surface condition, and the array length and orientation used. Findings from this study have immediate application and is envisaged to be useful for critical civil infrastructure monitoring and assessment.

Surface Resistance Measurements and Estimate of the Beam-Induced Resistive Wall Heating of the LHC Dipole Beam Screen

CERN Document Server

Caspers, Friedhelm; Ruggiero, F; Tan, J

1999-01-01

An estimate of the resistive losses in the LHC beam screen is given from cold surface resistance measurements using the shielded pair technique, with particular emphasis on the effect of a high magnetic field. Two different copper coating methods, namely electro-deposition and co-lamination, have been evaluated. Experimental data are compared with theories including the anomalous skin effect and the magneto-resistance effect. It is shown whether the theory underestimates or not the losses depends strongly on the RRR value, on the magnetic field and on the surface characteristics. In the pessimistic case and for nominal machine parameters, the estimated beam-induced resistive wall heating can be as large as 260 mW/m for two circulating beams.

Analytical method for establishing indentation rolling resistance

Science.gov (United States)

Gładysiewicz, Lech; Konieczna, Martyna

2018-01-01

Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

Arrester Resistive Current Measuring System Based on Heterogeneous Network

Science.gov (United States)

Zhang, Yun Hua; Li, Zai Lin; Yuan, Feng; Hou Pan, Feng; Guo, Zhan Nan; Han, Yue

2018-03-01

Metal Oxide Arrester (MOA) suffers from aging and poor insulation due to long-term impulse voltage and environmental impact, and the value and variation tendency of resistive current can reflect the health conditions of MOA. The common wired MOA detection need to use long cables, which is complicated to operate, and that wireless measurement methods are facing the problems of poor data synchronization and instability. Therefore a novel synchronous measurement system of arrester current resistive based on heterogeneous network is proposed, which simplifies the calculation process and improves synchronization, accuracy and stability and of the measuring system. This system combines LoRa wireless network, high speed wireless personal area network and the process layer communication, and realizes the detection of arrester working condition. Field test data shows that the system has the characteristics of high accuracy, strong anti-interference ability and good synchronization, which plays an important role in ensuring the stable operation of the power grid.

Measuring the electrical resistivity and contact resistance of vertical carbon nanotube bundles for application as interconnects

International Nuclear Information System (INIS)

Chiodarelli, Nicolo'; Li, Yunlong; Arstila, Kai; Richard, Olivier; Cott, Daire J; Heyns, Marc; De Gendt, Stefan; Groeseneken, Guido; Vereecken, Philippe M; Masahito, Sugiura; Kashiwagi, Yusaku

2011-01-01

Carbon nanotubes (CNT) are known to be materials with potential for manufacturing sub-20 nm high aspect ratio vertical interconnects in future microchips. In order to be successful with respect to contending against established tungsten or copper based interconnects, though, CNT must fulfil their promise of also providing low electrical resistance in integrated structures using scalable integration processes fully compatible with silicon technology. Hence, carefully engineered growth and integration solutions are required before we can fully exploit their potentialities. This work tackles the problem of optimizing a CNT integration process from the electrical perspective. The technique of measuring the CNT resistance as a function of the CNT length is here extended to CNT integrated in vertical contacts. This allows extracting the linear resistivity and the contact resistance of the CNT, two parameters to our knowledge never reported separately for vertical CNT contacts and which are of utmost importance, as they respectively measure the quality of the CNT and that of their metal contacts. The technique proposed allows electrically distinguishing the impact of each processing step individually on the CNT resistivity and the CNT contact resistance. Hence it constitutes a powerful technique for optimizing the process and developing CNT contacts of superior quality. This can be of relevant technological importance not only for interconnects but also for all those applications that rely on the electrical properties of CNT grown with a catalytic chemical vapor deposition method at low temperature.

Noise thermometry - a new temperature measuring method

International Nuclear Information System (INIS)

Brixy, H.; Hecker, R.; Rittinghaus, K.F.

1975-01-01

The thermal Johnson-Niquist noise is the basis of noise thermometry. This temperature measuring method is, e.g., of interest insofar as the noise thermometer gives absolute values as a primary thermometer and is in principle extensively independent of environmental influences and material properties. The resistance values of the measuring probe are about 10 Ohm to a few kOhm. The demands of electronics are high, the self-noise of the measuring apparatus must be as small as possible; a comparative measuring method is advantageous. 1 to 2,500 K are given as a possible temperature range. An accuracy of 0.1% could be achieved in laboratory measurements. Temperature measurements to be used in operation in a few nuclear reactors are mentioned. (HP/LH) [de

A simple approach to measure the surface resistivity of insulating materials

DEFF Research Database (Denmark)

Yang, Zhenyu; Wang, Qian

2011-01-01

A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V ...... for different materials, source voltages, and serially connected resistors. The testing results showed that the developed system and methods can provide a reasonably accurate measurement of surface resistivity of insulating materials in a robust and economic manner.......A simple approach for measuring high surface resistivity of insulating materials using standard laboratory equipments is proposed. The developed system consists of a DC power transformer, a concentric ring probe assembly and a digital multi-meter. The DC power transformer can provide either 500V...... or 250V DC signal. The probe assembly is constructed according to Danish Standard (DS/EN 1149-1:2006). The multi-meter (Agilent 3440 1A 6½) is used to measure the micro voltage over a known resistor which is serially connected with electrodes in the probe assembly. In order to obtain reliable...

Analytical method for establishing indentation rolling resistance

Directory of Open Access Journals (Sweden)

Gładysiewicz Lech

2018-01-01

Full Text Available Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

Susceptibility Testing by Polymerase Chain Reaction DNA Quantitation: A Method to Measure Drug Resistance of Human Immunodeficiency Virus Type 1 Isolates

Science.gov (United States)

Eron, Joseph J.; Gorczyca, Paul; Kaplan, Joan C.; D'Aquila, Richard T.

1992-04-01

Polymerase chain reaction (PCR) DNA quantitation (PDQ) susceptibility testing rapidly and directly measures nucleoside sensitivity of human immunodeficiency virus type 1 (HIV-1) isolates. PCR is used to quantitate the amount of HIV-1 DNA synthesized after in vitro infection of peripheral blood mononuclear cells. The relative amounts of HIV-1 DNA in cell lysates from cultures maintained at different drug concentrations reflect drug inhibition of virus replication. The results of PDQ susceptibility testing of 2- or 3-day cultures are supported by assays measuring HIV-1 p24 antigen production in supernatants of 7- or 10-day cultures. DNA sequence analyses to identify mutations in the reverse transcriptase gene that cause resistance to 3'-azido-3'-deoxythymidine also support the PDQ results. With the PDQ method, both infectivity titration and susceptibility testing can be performed on supernatants from primary cultures of peripheral blood mononuclear cells. PDQ susceptibility testing should facilitate epidemiologic studies of the clinical significance of drug-resistant HIV-1 isolates.

Simple method for resistance measurements on thin films and bulk of high T_c superconducting materials

Science.gov (United States)

Alzetta, G.; Arimondo, E.; Celli, R. M.; Fuso, F.

1994-08-01

Two experimental techniques for measuring resistivity behaviour of high T_c ceramic superconductors in bulk or thin films are described. Particular attention has been given to the development of a four point contact system, easy to use for reliable resistance measurements under repeated, wide thermal cycles. On expose deux méthodes de mesure de la résistivité des supraconducteurs HTc en forme de couches minces déposées sur un substrat ou des céramiques frittées. Le dispositif de mesure, qui a été réalisé avec quatre contacts élastiques, permet d'obtenir des résultats reproductibles dans de très larges intervalles de température.

A study on measurement of radiation resistance of Pyronema domesticum sclerotia

International Nuclear Information System (INIS)

Aoshuang, Y.; Ailian, W.; Ying, Z.

2000-01-01

Measurements of radiation resistance have been carried out using two strains of Pyronema domesticum which were isolated from Chinese cotton swab gauze. A 'sand-washing' technique was developed to overcome the difficulties when harvesting sclerotia spores from cultured plates and preparing spore suspensions for further use. Three types of microbial preparations, spore suspension, inoculated cotton and spore dot, were exposed to gamma radiation. A dose-survival curve method and a fraction positive method were employed to determine radiation resistance. D 10 values derived from this study are within the range of 2.0-3.0 kGy. Concerns associated with the current study indicate that further work is needed. (author)

Use of Direct Current Resistivity Measurements to Assess AISI 304 Austenitic Stainless Steel Sensitization

OpenAIRE

Mesquita, Ramaiany Carneiro; Mecury, José Manoel Rivas; Tanaka, Auro Atsumi; Sousa, Regina Célia de

2015-01-01

This paper describes the feasibility of using direct current electrical resistivity measurements to evaluate AISI 304 austenitic stainless steel sensitization. ASTM A262 – Practice A and double loop electrochemical potentiodynamic reactivation (DL-EPR) tests were performed to assess the degree of sensitization (DoS) qualitatively and quantitatively, and electrical resistivity (ER) was measured by the four-point direct-current potential drop method. The results indicate that the DoS incr...

Determining the Resistivity of Resistive Sheets Using Transmission Measurements

National Research Council Canada - National Science Library

Hyde, IV, Milo W

2006-01-01

In September 2005, radar cross section (RCS) measurements were made of resistive sheets, or R-cards, wrapped around a polystyrene foam cylinder to compare with a newly developed theoretical RCS prediction technique...

Thermopower measurement under high pressure using 'seesaw heating method'

International Nuclear Information System (INIS)

Hedo, M; Nakamura, D; Takaesu, Y; Yagasaki, K; Nakama, T; Fujiwara, T; Uchima, K

2010-01-01

We have developed a set-up with modified 'seesaw heating method' for the thermopower measurement under pressures P up to 3 GPa at the temperature range between 2 K and 300 K. By using this set-up, the thermopower and electrical resistivity of the single crystalline YbMn 2 Ge 2 under high pressure were measured with enough accuracy. S(T) curve shows the characteristic feature at the magnetic transition in all pressure range, while no evidence of the magnetic phase transition is observed in ρ(T) at P > 1.25 GPa. The measurement results indicate that the simultaneous measurement of the thermopower and electrical resistivity is a useful tool to study the pressure-induced phase transitions.

USING SESSION RPE TO MONITOR DIFFERENT METHODS OF RESISTANCE EXERCISE

Directory of Open Access Journals (Sweden)

Alison D. Egan

2006-06-01

Full Text Available The purpose of this study was to compare session rating of perceived exertion for different resistance training techniques in the squat exercise. These techniques included traditional resistance training, super slow, and maximal power training. Fourteen college-age women (Mean ± SD; age = 22 ± 3 years; height = 1.68 ± 0. 07 m completed three experimental trials in a randomized crossover design. The traditional resistance training protocol consisted of 6 sets of 6 repetitions of squats using 80% of 1-RM. The super slow protocol consisted of 6 sets of 6 repetitions using 55% of 1-RM. The maximal power protocol consisted of 6 sets of 6 repetitions using 30% of 1-RM. Rating of perceived exertion (RPE measures were obtained following each set using Borg's CR-10 scale. In addition, a session RPE value was obtained 30 minutes following each exercise session. When comparing average RPE and session RPE, no significant difference was found. However, power training had significantly lower (p < 0.05 average and session RPE (4.50 ± 1.9 and 4.5 ± 2.1 compared to both super slow training (7.81 ± 1.75 and 7.43 ± 1.73 and traditional training (7.33 ± 1.52 and 7.13 ± 1.73. The results indicate that session RPE values are not significantly different from the more traditional methods of measuring RPE during exercise bouts. It does appear that the resistance training mode that is used results in differences in perceived exertion that does not relate directly to the loading that is used. Using session RPE provides practitioners with the same information about perceived exertion as the traditional RPE measures. Taking a single measure following a training session would appear to be much easier than using multiple measures of RPE throughout a resistance training workout. However, practitioners should also be aware that the RPE does not directly relate to the relative intensity used and appears to be dependent on the mode of resistance exercise that is used

Method And Apparatus For Two Dimensional Surface Property Analysis Based On Boundary Measurement

Science.gov (United States)

Richardson, John G.

2005-11-15

An apparatus and method for determining properties of a conductive film is disclosed. A plurality of probe locations selected around a periphery of the conductive film define a plurality of measurement lines between each probe location and all other probe locations. Electrical resistance may be measured along each of the measurement lines. A lumped parameter model may be developed based on the measured values of electrical resistance. The lumped parameter model may be used to estimate resistivity at one or more selected locations encompassed by the plurality of probe locations. The resistivity may be extrapolated to other physical properties if the conductive film includes a correlation between resistivity and the other physical properties. A profile of the conductive film may be developed by determining resistivity at a plurality of locations. The conductive film may be applied to a structure such that resistivity may be estimated and profiled for the structure's surface.

Measurement of direct currents of under 10-10 ampere and of resistances of 1012 Ω for a direct current

International Nuclear Information System (INIS)

Vagner, J.

1965-01-01

Measurement of weak direct currents by Townsend's method using a vibrating condenser electrometer. Development of a current generator giving a pico-ampere independently of the resistance of the circuit used. Development of generators giving currents which may be adjusted continuously and exactly (0.1 to 1 pico-ampere, 1 to 10 pico-amperes, 10 to 100 pico-amperes). Measurement of very high resistances (10 12 Ω) by three different methods. Graphs are made by plotting the value of the resistance against the potential difference applied across it (from 50 milli-volts to 50 volts). Two methods use adjustable current generators and the third is applicable to the measurement of resistances of between 10 7 and 10 13 Ω using a series of condensers ranging from 50 pico-farads to 10 micro-farads. The accuracy of the measurements is between 0. 5 and 1 per cent. (author) [fr

Measuring the thermal insulation and evaporative resistance of sleeping bags using a supine sweating fabric manikin

International Nuclear Information System (INIS)

Wu, Y S; Fan, Jintu

2009-01-01

For testing the thermal insulation of sleeping bags, standard test methods and procedures using heated manikins are provided in ASTM F1720-06 and EN 13537:2002. However, with regard to the evaporative resistance of sleeping bags, no instrument or test method has so far been established to give a direct measurement. In this paper, we report on a novel supine sweating fabric manikin system for directly measuring the evaporative resistance of sleeping bags. Eleven sleeping bags were tested using the manikin under the isothermal condition, namely, both the mean skin temperature of the manikin and that of the environment were controlled to be the same at 35 °C, with the wind speed and ambient relative humidity at 0.3 m s −1 and 50%, respectively. The results showed that the novel supine sweating fabric manikin is reproducible and accurate in directly measuring the evaporative resistance of sleeping bags, and the measured evaporative resistance can be combined with thermal insulation to calculate the moisture permeability index of sleeping bags

Electrical resistivity measurement to predict uniaxial compressive ...

Indian Academy of Sciences (India)

Electrical resistivity values of 12 different igneous rocks were measured on core samples using a resistivity meter in the ... It was seen that the UCS and tensile strength values were linearly correlated with the ..... Innovation 2 20. Archie G E ...

Parallelized Three-Dimensional Resistivity Inversion Using Finite Elements And Adjoint State Methods

Science.gov (United States)

Schaa, Ralf; Gross, Lutz; Du Plessis, Jaco

2015-04-01

The resistivity method is one of the oldest geophysical exploration methods, which employs one pair of electrodes to inject current into the ground and one or more pairs of electrodes to measure the electrical potential difference. The potential difference is a non-linear function of the subsurface resistivity distribution described by an elliptic partial differential equation (PDE) of the Poisson type. Inversion of measured potentials solves for the subsurface resistivity represented by PDE coefficients. With increasing advances in multichannel resistivity acquisition systems (systems with more than 60 channels and full waveform recording are now emerging), inversion software require efficient storage and solver algorithms. We developed the finite element solver Escript, which provides a user-friendly programming environment in Python to solve large-scale PDE-based problems (see https://launchpad.net/escript-finley). Using finite elements, highly irregular shaped geology and topography can readily be taken into account. For the 3D resistivity problem, we have implemented the secondary potential approach, where the PDE is decomposed into a primary potential caused by the source current and the secondary potential caused by changes in subsurface resistivity. The primary potential is calculated analytically, and the boundary value problem for the secondary potential is solved using nodal finite elements. This approach removes the singularity caused by the source currents and provides more accurate 3D resistivity models. To solve the inversion problem we apply a 'first optimize then discretize' approach using the quasi-Newton scheme in form of the limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) method (see Gross & Kemp 2013). The evaluation of the cost function requires the solution of the secondary potential PDE for each source current and the solution of the corresponding adjoint-state PDE for the cost function gradients with respect to the subsurface

About the use of spatial interpolation methods to denoising Moroccan resistivity data phosphate “disturbances” map

Directory of Open Access Journals (Sweden)

Mahacine Amrani

2008-06-01

Full Text Available Several methods are currently used to optimize edges and contours of geophysical data maps. A resistivity map was expectedto allow the electrical resistivity signal to be imaged in 2D in Moroccan resistivity survey in the phosphate mining domain. Anomalouszones of phosphate deposit “disturbances” correspond to resistivity anomalies. The resistivity measurements were taken at 5151discrete locations. Much of the geophysical spatial analysis requires a continuous data set and this study is designed to create that surface. This paper identifies the best spatial interpolation method to use for the creation of continuous data for Moroccan resistivity data of phosphate “disturbances” zones. The effectiveness of our approach for successfully reducing noise has been used much successin the analysis of stationary geophysical data as resistivity data. The interpolation filtering approach methods applied to modelingsurface phosphate “disturbances” was found to be consistently useful.

RESISTANCE TO INNOVATION: ESSENCE, PREVENTIVE MEASURES AND WAYS OUT

Directory of Open Access Journals (Sweden)

V. I. Zagvyazinsky

2014-01-01

Full Text Available The paper raises the issue of school teachers’ resistance to innovations related to modernization procedures, updates of educational content, methods and forms. The rejection of innovations is regarded by the authors as a psychological and pedagogical phenomenon; its roots and causes being analyzed including the consequences of some ineffective, poorly developed and even harmful innovations introduced or proposed by the Russian Ministry of Education and Science. The research findings demonstrate different innovation barriers along with the resulting inner skepticism and its external manifestation. However, in spite of partially justified skepticism, the authors maintain that the firm resistance to any innovation adversely affects both the education quality and teachers’ personal and professional characteristics. In conclusion, the paper suggests some preventive measures for overcoming teachers’ resistance to positive innovations in educational practices, and describes a successful experience of one of the rural schools applying a psychological mechanism of internalization of innovations. Additionally, the role of the school principal in developing teachers’ motivation for innovations is emphasized.

Measurement of the Transverse Spitzer Resistivity during Collisional Magnetic Reconnection

International Nuclear Information System (INIS)

Trintchouk, F.; Yamada, M.; Ji, H.; Kulsrud, R.M.; Carter, T.A.

2000-01-01

Measurement of the transverse resistivity was carried out in a reconnecting current sheet where the mean free path for the Coulomb collision is smaller than the thickness of the sheet. In a collisional neutral sheet without a guide field, the transverse resistivity is directly related to the reconnection rate. A remarkable agreement is found between the measured resistivity and the classical value derived by L. Spitzer. In his calculation the transverse resistivity for the electrons is higher than the parallel resistivity by a factor of 1.96. The measured values have verified this theory to within 30% errors

Contribution of soil electric resistivity measurements to the studies on soil/grapevine water relations

Directory of Open Access Journals (Sweden)

Etienne Goulet

2006-06-01

Full Text Available The classical techniques that allow to quantify the soil water status such as the gravimetric method or the use of neutrons probes do not give access to the volume of soil explored by the plant root system. On the contrary, electric tomography can be used to have a global vision on the water exchange area between soil and plant. The measurement of soil electric resistivity, as a non destructive, spatially integrative technique, has recently been introduced into viticulture. The use of performing equipment and adapted software allows for rapid data processing and gives the possibility to spatialize the variations of soil texture or humidity in two or three dimensions. Soil electric resistivity has been tested for the last three years at the Experimental Unit on Grapevine and Vine, INRA, Angers, France, to study the water supply to the vine in different “terroir” conditions. Resistivity measurements were carried out with the resistivity meter Syscal R1+ (Iris Instruments, France equipped with 21 electrodes. Those electrodes were lined up on the soil surface in a direction perpendiculary to 5 grapevine rows with an electrode spacing of 0.5 m. and a dipole-dipole arrangement. Resistivity measurements were performed on the same place at different times in order to study soil moisture variations. This experimental set up has permitted to visualise the soil stratification and individualize some positive electric anomalies corresponding to preferential drying ; this desiccation could be attributed to grapevine root activity. The soil bulk subject to the water up-take could be defined more precisely and in some types of soil, available water may even be quantified. Terroir effect on grapevine root activity has also been shown up on two different experimental parcels through electric tomography and first results indicate that it is possible to monitor the effects of soil management (inter-row grassing or different rootstocks on the water supply to the

47 CFR 73.54 - Antenna resistance and reactance measurements.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna resistance and reactance measurements... measurements. (a) The resistance of an omnidirectional series fed antenna is measured at either the base of the... the point of common radiofrequency input to the directional antenna system after the antenna has been...

A portable borehole temperature logging system using the four-wire resistance method

Science.gov (United States)

Erkan, Kamil; Akkoyunlu, Bülent; Balkan, Elif; Tayanç, Mete

2017-12-01

High-quality temperature-depth information from boreholes with a depth of 100 m or more is used in geothermal studies and in studies of climate change. Electrical wireline tools with thermistor sensors are capable of measuring borehole temperatures with millikelvin resolution. The use of a surface readout mode allows analysis of the thermally conductive state of a borehole, which is especially important for climatic and regional heat flow studies. In this study we describe the design of a portable temperature logging tool that uses the four-wire resistance measurement method. The four-wire method enables the elimination of cable resistance effects, thus allowing millikelvin resolution of temperature data at depth. A preliminary two-wire model of the system is also described. The portability of the tool enables one to collect data from boreholes down to 300 m, even in locations with limited accessibility.

Ultra-shallow junction (USJ) sheet resistance measurements with a non-penetrating four point probe

International Nuclear Information System (INIS)

Benjamin, M.C.; Hillard, R.J.; Borland, J.O.

2005-01-01

An accurate method to measure the four point probe (4PP) sheet resistance (R S ) of ultra shallow junction (USJ) Source-Drain Extension structures is described. The method utilizes Elastic Material probes (EM-probes) to form non-penetrating contacts to the silicon surface [R.J. Hillard, P.Y. Hung, William Chism, C. Win Ye, W.H. Howland, L.C. Tan, C.E. Kalnas, Characterization and Metrology for ULSI Technology, AIP Conference proceedings 683 (2003) 802.]. The probe design is kinematic and the force is controlled to ensure elastic deformation of the probe material. The probe material is such that large direct tunneling currents can flow through the native oxide thereby forming a low impedance contact. Sheet resistance measurements on USJ implanted P+/N structures with Secondary Ion Mass Spectroscopy (SIMS) junction depths less than 15 nm have been measured. The method is demonstrated on implanted USJ structures and found to be consistent with expectations

Shunt resistance and saturation current determination in CdTe and CIGS solar cells. Part 2: application to experimental IV measurements and comparison with other methods

Science.gov (United States)

Rangel-Kuoppa, Victor-Tapio; Albor-Aguilera, María-de-Lourdes; Hérnandez-Vásquez, César; Flores-Márquez, José-Manuel; Jiménez-Olarte, Daniel; Sastré-Hernández, Jorge; González-Trujillo, Miguel-Ángel; Contreras-Puente, Gerardo-Silverio

2018-04-01

In this Part 2 of this series of articles, the procedure proposed in Part 1, namely a new parameter extraction technique of the shunt resistance (R sh ) and saturation current (I sat ) of a current-voltage (I-V) measurement of a solar cell, within the one-diode model, is applied to CdS-CdTe and CIGS-CdS solar cells. First, the Cheung method is used to obtain the series resistance (R s ) and the ideality factor n. Afterwards, procedures A and B proposed in Part 1 are used to obtain R sh and I sat . The procedure is compared with two other commonly used procedures. Better accuracy on the simulated I-V curves used with the parameters extracted by our method is obtained. Also, the integral percentage errors from the simulated I-V curves using the method proposed in this study are one order of magnitude smaller compared with the integral percentage errors using the other two methods.

Pedestrian fall safety assessments improved understanding on slip resistance measurements and investigations

CERN Document Server

Kim, In-Ju

2017-01-01

This book examines pedestrian shoe-floor slip resistance from an engineering standpoint in order to better understand friction and wear behavior. This analysis includes an extensive investigation into the surface properties of shoes and flow, and the measurement of dynamic friction and other mechanical and physical aspects of shoe-floor tribology. Lastly, the book proposes a measurement concept for the identification and classification of operational floor surfaces under a range of different conditions. Novel techniques and methods are proposed that can improve the reliability of slip resistance assessments. The current state of knowledge is critically examined and discussed from a tribological perspective, including aspects like friction, wear, lubrication and the mechanical behavior of shoes, floors and their wider environment. Further, the book reports on extensive experimental investigations into the topographical characteristics of shoe and floor surfaces and how they affect slip resistance. Slips result...

Design of a Horizontal Penetrometer for Measuring On‑the‑Go Soil Resistance

Directory of Open Access Journals (Sweden)

Davut Karayel

2010-10-01

Full Text Available Soil compaction is one of the main negative factors that limits plant growth and crop yield. Therefore, it is important to determine the soil resistance level and map it for the field to find solutions for the negative effects of the compaction. Nowadays, high powered communication technology and computers help us on this issue within the approach of precision agriculture applications. This study is focused on the design of a penetrometer, which can make instantaneous soil resistance measurements in the soil horizontally and data acquisition software based on the GPS (Global Positioning System. The penetrometer was designed using commercial 3D parametric solid modelling design software. The data acquisition software was developed in Microsoft Visual Basic.NET programming language. After the design of the system, manufacturing and assembly of the system was completed and then a field experiment was carried out. According to the data from GPS and penetration resistance values which are collected in Microsoft SQL Server database, a Kriging method by ArcGIS was used and soil resistance was mapped in the field for a soil depth of 40 cm. During operation, no faults, either in mechanical and software parts, were seen. As a result, soil resistance values of 0.2 MPa and 3 MPa were obtained as minimum and maximum values, respectively. In conclusion, the experimental results showed that the designed system works quite well in the field and the horizontal penetrometer is a practical tool for providing on‑line soil resistance measurements. This study contributes to further research for the development of on-line soil resistance measurements and mapping within the precision agriculture applications.

Design of a horizontal penetrometer for measuring on-the-go soil resistance.

Science.gov (United States)

Topakci, Mehmet; Unal, Ilker; Canakci, Murad; Celik, Huseyin Kursat; Karayel, Davut

2010-01-01

Soil compaction is one of the main negative factors that limits plant growth and crop yield. Therefore, it is important to determine the soil resistance level and map it for the field to find solutions for the negative effects of the compaction. Nowadays, high powered communication technology and computers help us on this issue within the approach of precision agriculture applications. This study is focused on the design of a penetrometer, which can make instantaneous soil resistance measurements in the soil horizontally and data acquisition software based on the GPS (Global Positioning System). The penetrometer was designed using commercial 3D parametric solid modelling design software. The data acquisition software was developed in Microsoft Visual Basic.NET programming language. After the design of the system, manufacturing and assembly of the system was completed and then a field experiment was carried out. According to the data from GPS and penetration resistance values which are collected in Microsoft SQL Server database, a Kriging method by ArcGIS was used and soil resistance was mapped in the field for a soil depth of 40 cm. During operation, no faults, either in mechanical and software parts, were seen. As a result, soil resistance values of 0.2 MPa and 3 MPa were obtained as minimum and maximum values, respectively. In conclusion, the experimental results showed that the designed system works quite well in the field and the horizontal penetrometer is a practical tool for providing on-line soil resistance measurements. This study contributes to further research for the development of on-line soil resistance measurements and mapping within the precision agriculture applications.

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing.

Science.gov (United States)

Xiao, Yue; Wang, Feng; Cui, Peide; Lei, Lei; Lin, Juntao; Yi, Mingwei

2018-05-29

Micro-surfacing is a widely used pavement preventive maintenance technology used all over the world, due to its advantages of fast construction, low maintenance cost, good waterproofness, and skid-resistance performance. This study evaluated the fine aggregate morphology and surface texture of micro-surfacing by AIMS (aggregate image measurement system), and explored the effect of aggregate morphology on skid-resistance of single-grade micro-surfacing. Sand patch test and British pendulum test were also used to detect skid-resistance for comparison with the image-based method. Wet abrasion test was used to measure skid-resistance durability for feasibility verification of single-grade micro-surfacing. The results show that the effect of Form2D on the skid-resistance of micro-surfacing is much stronger than that of angularity. Combining the feasibility analysis of durability and skid-resistance, 1.18⁻2.36 grade micro-surfacing meets the requirements of durability and skid-resistance at the same time. This study also determined that, compared with British pendulum test, the texture result obtained by sand patch test fits better with results of image method.

Effects of contact resistance on electrical conductivity measurements of SiC-based materials

Energy Technology Data Exchange (ETDEWEB)

Youngblood, G.E.; Thomsen, E.C.; Henager, C.H., E-mail: chuck.henager@pnnl.gov

2013-11-15

A combination 2/4-probe method was used to measure electrical resistances across a pure, monolithic CVD-SiC disc sample with contact resistance at the SiC/metallic electrode interfaces. By comparison of the almost simultaneous 2/4-probe measurements, the specific contact resistance (R{sub c}) and its temperature dependence were determined for two types (sputtered gold and porous nickel) electrodes from room temperature (RT) to ∼973 K. The R{sub c}-values behaved similarly for each type of metallic electrode: R{sub c} > ∼1000 Ω cm{sup 2} at RT, decreasing continuously to ∼1–10 Ω cm{sup 2} at 973 K. The temperature dependence of the inverse R{sub c} indicated thermally activated electrical conduction across the SiC/metallic interface with an apparent activation energy of ∼0.3 eV. For the flow channel insert application in a fusion reactor blanket, contact resistance potentially could reduce the transverse electrical conductivity by about 50%.

Measurement of resistivity changes in irradiated microscopy discs

International Nuclear Information System (INIS)

Sagisaka, M.; Isobe, Y.; Edwards, D.J.; Garner, F.; Okita, T.

2007-01-01

Full text of publication follows: The successful operation of next generation fusion or fission devices will require the development of new inspection tools to allow in-situ, non-destructive examination of structural components which experience the deleterious effects of neutron irradiation. Such development requires that an understanding of how radiation-induced microstructural alteration contributes to macroscopic changes in physical properties such as electrical resistivity. This in turn requires test specimens spanning a range of microstructural alteration. Frequently such specimens are very small and available test techniques are not suitable for their examination. An example is the use of thin TEM specimens (3 mm diameter, 0.3 mm thick) used for electron microscopy. A unique four probe electrical resistivity measurement system suitable for examining I EM specimens was developed for investigating small resistivity changes due to void swelling and other microstructural features. Since this system uses momentarily-high electrical currents (0.5 A maximum), electrical resistivity changes can be measured rather precisely. This paper reports results of resistivity change measurements made on model Fe-Cr-Ni-Zr austenitic alloys irradiated in the Fast Flux Test Facility in the Materials Open Test Assembly to doses ranging from 0.38 to 19.2 dpa. Microscopy was used to determine the radiation-induced microstructure. A correlation is presented for resistivity changes arising primarily from void swelling. (authors)

Biotechnological Methods for Precise Diagnosis of Methicillin Resistance in Staphylococci

Directory of Open Access Journals (Sweden)

Aija Zilevica

2005-04-01

Full Text Available Antimicrobial resistance is one of the most urgent problems in medicine nowadays. The purpose of the study was to investigate the microorganisms resistant to first-line antimicrobials, including gram-positive cocci, particularly the methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococci, the major agents of nosocomial infections. Owing to the multi-resistance of these agents, precise diagnosis of the methicillin resistance of Staphylococci is of greatest clinical importance. It is not enough to use only conventional microbiological diagnostic methods. Biotechnological methods should be also involved. In our studies, the following methicillin resistance identification methods were used: the disk diffusion method, detection of the mecA gene by PCR, E-test and Slidex MRSA test. For molecular typing, PFGL, RAPD tests and detection of the coa gene were used. All the MRS strains were multiresistant to antibacterials. No vancomycine resistance was registered.

Interpretation of deep directional resistivity measurements acquired in high-angle and horizontal wells using 3-D inversion

Science.gov (United States)

Puzyrev, Vladimir; Torres-Verdín, Carlos; Calo, Victor

2018-05-01

The interpretation of resistivity measurements acquired in high-angle and horizontal wells is a critical technical problem in formation evaluation. We develop an efficient parallel 3-D inversion method to estimate the spatial distribution of electrical resistivity in the neighbourhood of a well from deep directional electromagnetic induction measurements. The methodology places no restriction on the spatial distribution of the electrical resistivity around arbitrary well trajectories. The fast forward modelling of triaxial induction measurements performed with multiple transmitter-receiver configurations employs a parallel direct solver. The inversion uses a pre-conditioned gradient-based method whose accuracy is improved using the Wolfe conditions to estimate optimal step lengths at each iteration. The large transmitter-receiver offsets, used in the latest generation of commercial directional resistivity tools, improve the depth of investigation to over 30 m from the wellbore. Several challenging synthetic examples confirm the feasibility of the full 3-D inversion-based interpretations for these distances, hence enabling the integration of resistivity measurements with seismic amplitude data to improve the forecast of the petrophysical and fluid properties. Employing parallel direct solvers for the triaxial induction problems allows for large reductions in computational effort, thereby opening the possibility to invert multiposition 3-D data in practical CPU times.

Electrical Methods: Resistivity Methods

Science.gov (United States)

Surface electrical resistivity surveying is based on the principle that the distribution of electrical potential in the ground around a current-carrying electrode depends on the electrical resistivities and distribution of the surrounding soils and rocks.

A new contact electric resistance technique for in-situ measurement of the electric resistance of surface films on metals in electrolytes at high temperatures and pressures

International Nuclear Information System (INIS)

Saario, T.; Marichev, V.A.

1993-01-01

Surface films play a major role in corrosion assisted cracking. A new Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films. The method has been upgraded for high temperature high pressure application. The technique can be used for any electrically conductive material in any environment including liquid, gas or vacuum. The technique has been used to determine in situ the electric resistance of films on metals during adsorption of water and anions, formation and destruction of oxides and hydrides, electroplating of metals and to study the electric resistance of films on semiconductors. The resolution of the CER technique is 10 -9 Ω, which corresponds to about 0.03 monolayers of deposited copper during electrochemical deposition Cu/Cu 2+ . Electric resistance data can be measured with a frequency of the order of one hertz, which enables one to follow in situ the kinetics of surface film related processes. The kinetics of these processes and their dependence on the environment, temperature, pH and electrochemical potential can be investigated

7 CFR 1755.406 - Shield or armor ground resistance measurements.

Science.gov (United States)

2010-01-01

...) The insulation resistance test set should have an output voltage not to exceed 500 volts dc and may be... 7 Agriculture 11 2010-01-01 2010-01-01 false Shield or armor ground resistance measurements. 1755... MATERIALS, AND STANDARD CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield...

Electromigration of hydrogen and deuterium in vanadium and niobium by a resistance method

International Nuclear Information System (INIS)

Peterson, D.T.; Jensen, C.L.

1978-01-01

The electric mobility of hydrogen and deuterium has been measured at 30 0 C in niobium (Cb) and vanadium by a resistance method. The electric mobility was found to be 5.7 x 10 -4 cm 2 /V-s for hydrogen and 2.8 x 10 -4 for deuterium in niobium. In vanadium the electric mobilities were 2.3 x 10 -3 and 1.3 x 10 -3 cm 2 /V-s for hydrogen and deuterium, respectively. The effective charges calculated using reported diffusion coefficients are positive and are slightly greater for deuterium than for hydrogen in both vanadium and niobium. The resistivity increase due to the hydrogen isotopes in vanadium and niobium was also measured. Hydrogen was found to contribute 0.65 μ ohm-cm/at. % and deuterium 0.58 μ ohm-cm/at. % to the resistivity of niobium. In vanadium, the solute resistivities were found to be 0.98 μ ohm-cm/at. % and 0.90 μ ohm-cm/at. % for hydrogen and deuterium, respectively

Characterising thermal resistances and capacitances of GaN high-electron-mobility transistors through dynamic electrothermal measurements

DEFF Research Database (Denmark)

Wei, Wei; Mikkelsen, Jan H.; Jensen, Ole Kiel

2014-01-01

This study presents a method to characterise thermal resistances and capacitances of GaN high-electron-mobility transistors (HEMTs) through dynamic electrothermal measurements. A measured relation between RF gain and the channel temperature (Tc) is formed and used for indirect measurements...

Study on strength estimation of soil cement used in the embedded pile method by electrical resistivity measurement

Science.gov (United States)

Mochida, Y.; Sakurai, Y.; Indra, H.; Karimi, A. L.

2017-11-01

Problems caused by poor quality control and quality assurance of the pre-boring embedded pile construction, such as on domestic apartment house is still occurring nowadays. An adequate consideration for invisible risks inside or below the ground is important in pile foundation construction therefore the demand for advanced and reliable quality assurance is increase in the future. In this research, to understand the quality of the construction at early stage, the compressive strength of cement-soil mixture of pile construction after 28 days is estimated using electrical resistivity value of the mixture. More accurate measurement for electrical resistivity value is conducted by inserting the electrodes without using potassium chloride solution as a catalyst. The result showed that there is a certain tendency in the electric resistivity value at the early age regarding to the type of soil (sand, clay) mixed in. The most accurate estimation was achieved from the electric resistivity value at the first day and several days onwards, and from the compressive strength after 3 days.

Determination of nonlinear resistance voltage-current relationships by measuring harmonics

Science.gov (United States)

Stafford, J. M.

1971-01-01

Test configuration measures harmonic signal amplitudes generated in nonlinear resistance. Vacuum-type voltmeter measures low frequency sinusoidal input signal amplitude and wave-analyzer measures amplitude of harmonic signals generated in junction. Input signal harmonics amplitude must not exceed that of harmonics generated in nonlinear resistance.

In-place measurement of specific electric resistance during precipitation of γ'-precipitating Ni base alloys

International Nuclear Information System (INIS)

Silomon, M.

1991-01-01

During precipitation and coarsening of a second phase, the electric resistance of an alloy changes. Continuous resistance measurement is possible during heat treatment and can be conducted with limited experimental effort; any metallographic determination of the temperature and time dependencies of structural changes, however, requires very high effort. For this reason, an instrument was set up which permits continuous measurement of the resistance at precipitation temperature and during heating or cooling, while providing sufficient resolution for minor changes. Both measuring methods are conducted on technologically relevant alloys such as Nimonic PE 16 and those based on Ni-20 At.% Cr with deliberately varied additions of Al and Ti (accompanying investigations: TEM, SANS, and calorimetry). Their usefulness for alloy development is discussed within the scope of current concepts of demixing kinetics and resistance of alloys. Essential results concern the matrix/γ'-phase mismatch, the Ni 2 Cr short range order, and determination of the γ'-solvus temperature. (orig.) With 53 figs., 4 tabs [de

How to measure and monitor antimicrobial consumption and resistance.

Science.gov (United States)

Grau, Santiago; Bou, Germán; Fondevilla, Esther; Nicolás, Jordi; Rodríguez-Maresca, Manuel; Martínez-Martínez, Luis

2013-09-01

Collateral damage caused by antibiotic use includes resistance, which could be reduced if the global inappropriate use of antibiotics, especially in low-income countries, could be prevented. Surveillance of antimicrobial consumption can identify and target practice areas for quality improvement, both in the community and in healthcare institutions. The defined daily dose, the usual adult dose of an antimicrobial for treating one patient for one day, has been considered useful for measuring antimicrobial prescribing trends within a hospital. Various denominators from hospital activity including beds, admissions and discharges have been used to obtain some standard ratios for comparing antibiotic consumption between hospitals and countries. Laboratory information systems in Clinical Microbiology Services are the primary resource for preparing cumulative reports on susceptibility testing results. This information is useful for planning empirical treatment and for adopting infection control measures. Among the supranational initiatives on resistance surveillance, the EARS-Net provides information about trends on antimicrobial resistance in Europe. Resistance is the consequence of the selective pressure of antibiotics, although in some cases these agents also promote resistance by favouring the emergence of mutations that are subsequently selected. Multiple studies have shown a relationship between antimicrobial use and emergence or resistance. While in some cases a decrease in antibiotic use was associated with a reduction in resistance rates, in many other situations this has not been the case, due to co-resistance and/or the low biological cost of the resistance mechanisms involved. New antimicrobial agents are urgently needed, which coupled with infection control measures will help to control the current problem of antimicrobial resistance. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Molecular detection methods of resistance to antituberculosis drugs in Mycobacterium tuberculosis.

Science.gov (United States)

Brossier, F; Sougakoff, W

2017-09-01

Molecular methods predict drug resistance several weeks before phenotypic methods and enable rapid implementation of appropriate therapeutic treatment. We aimed to detail the most representative molecular tools used in routine practice for the rapid detection of resistance to antituberculosis drugs among Mycobacterium tuberculosis strains. The molecular diagnosis of resistance to antituberculosis drugs in clinical samples or from in vitro cultures is based on the detection of the most common mutations in the genes involved in the development of resistance in M. tuberculosis strains (encoding either protein targets of antibiotics, or antibiotic activating enzymes) by commercial molecular kits or by sequencing. Three hypotheses could explain the discrepancies between the genotypic results and the phenotypic drug susceptibility testing results: a low percentage of resistant mutants precluding the detection by genotypic methods on the primary culture; a low level of resistance not detected by phenotypic testing; and other resistance mechanisms not yet characterized. Molecular methods have varying sensitivity with regards to detecting antituberculosis drug resistance; that is why phenotypic susceptibility testing methods are mandatory for detecting antituberculosis drug-resistant isolates that have not been detected by molecular methods. The questionable ability of existing phenotypic and genotypic drug susceptibility testing to properly classify strains as susceptible or resistant, and at what level of resistance, was raised for several antituberculosis agents. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Evaluation of Fine Aggregate Morphology by Image Method and Its Effect on Skid-Resistance of Micro-Surfacing

Directory of Open Access Journals (Sweden)

Yue Xiao

2018-05-01

Full Text Available Micro-surfacing is a widely used pavement preventive maintenance technology used all over the world, due to its advantages of fast construction, low maintenance cost, good waterproofness, and skid-resistance performance. This study evaluated the fine aggregate morphology and surface texture of micro-surfacing by AIMS (aggregate image measurement system, and explored the effect of aggregate morphology on skid-resistance of single-grade micro-surfacing. Sand patch test and British pendulum test were also used to detect skid-resistance for comparison with the image-based method. Wet abrasion test was used to measure skid-resistance durability for feasibility verification of single-grade micro-surfacing. The results show that the effect of Form2D on the skid-resistance of micro-surfacing is much stronger than that of angularity. Combining the feasibility analysis of durability and skid-resistance, 1.18–2.36 grade micro-surfacing meets the requirements of durability and skid-resistance at the same time. This study also determined that, compared with British pendulum test, the texture result obtained by sand patch test fits better with results of image method.

Method of superconducting joint and its measurement

International Nuclear Information System (INIS)

Kim, Woo Gon; Lee, Ho Jin; Hong, Gye Won

1994-04-01

The development of joint techniques for superconducting wires is essential to fabricate the high quality superconducting magnet. In this report, the various joining methods and their measuring techniques were reviewed. In order to fabricate a precise superconducting magnet, joining and measuring experiment by using the field decay technique carried out. The contact resistance of coupled specimens with joint was measured as 3.0 x 10 -15 ohm at 1 Tesla which is lower than that of the real operating condition of MRI magnet. It is expected that these data can be used to design and fabricate the superconducting magnets successfully. (Author) 12 refs., 20 figs., 2 tabs

The Use of Resistivity Methods in Terrestrial Forensic Searches

Science.gov (United States)

Wolf, R. C.; Raisuddin, I.; Bank, C.

2013-12-01

The increasing use of near-surface geophysical methods in forensic searches has demonstrated the need for further studies to identify the ideal physical, environmental and temporal settings for each geophysical method. Previous studies using resistivity methods have shown promising results, but additional work is required to more accurately interpret and analyze survey findings. The Ontario Provincial Police's UCRT (Urban Search and Rescue; Chemical, Biolgical, Radiological, Nuclear and Explosives; Response Team) is collaborating with the University of Toronto and two additional universities in a multi-year study investigating the applications of near-surface geophysical methods to terrestrial forensic searches. In the summer of 2012, on a test site near Bolton, Ontario, the OPP buried weapons, drums and pigs (naked, tarped, and clothed) to simulate clandestine graves and caches. Our study aims to conduct repeat surveys using an IRIS Syscal Junior with 48 electrode switching system resistivity-meter. These surveys will monitor changes in resistivity reflecting decomposition of the object since burial, and identify the strengths and weaknesses of resistivity when used in a rural, clandestine burial setting. Our initial findings indicate the usefulness of this method, as prominent resistivity changes have been observed. We anticipate our results will help to assist law enforcement agencies in determining the type of resistivity results to expect based on time since burial, depth of burial and state of dress of the body.

A Novel Crosstalk Suppression Method of the 2-D Networked Resistive Sensor Array

Directory of Open Access Journals (Sweden)

Jianfeng Wu

2014-07-01

Full Text Available The 2-D resistive sensor array in the row–column fashion suffered from the crosstalk problem for parasitic parallel paths. Firstly, we proposed an Improved Isolated Drive Feedback Circuit with Compensation (IIDFCC based on the voltage feedback method to suppress the crosstalk. In this method, a compensated resistor was specially used to reduce the crosstalk caused by the column multiplexer resistors and the adjacent row elements. Then, a mathematical equivalent resistance expression of the element being tested (EBT of this circuit was analytically derived and verified by the circuit simulations. The simulation results show that the measurement method can greatly reduce the influence on the EBT caused by parasitic parallel paths for the multiplexers’ channel resistor and the adjacent elements.

Comparison of mobility extraction methods based on field-effect measurements for graphene

Directory of Open Access Journals (Sweden)

Hua Zhong

2015-05-01

Full Text Available Carrier mobility extraction methods for graphene based on field-effect measurements are explored and compared according to theoretical analysis and experimental results. A group of graphene devices with different channel lengths were fabricated and measured, and carrier mobility is extracted from those electrical transfer curves using three different methods. Accuracy and applicability of those methods were compared. Transfer length method (TLM can obtain accurate density dependent mobility and contact resistance at relative high carrier density based on data from a group of devices, and then can act as a standard method to verify other methods. As two of the most popular methods, direct transconductance method (DTM and fitting method (FTM can extract mobility easily based on transfer curve of a sole graphene device. DTM offers an underestimated mobility at any carrier density owing to the neglect of contact resistances, and the accuracy can be improved through fabricating field-effect transistors with long channel and good contacts. FTM assumes a constant mobility independent on carrier density, and then can obtain mobility, contact resistance and residual density stimulations through fitting a transfer curve. However, FTM tends to obtain a mobility value near Dirac point and then overestimates carrier mobility of graphene. Comparing with the DTM and FTM, TLM could offer a much more accurate and carrier density dependent mobility, that reflects the complete properties of graphene carrier mobility.

Application of Monte Carlo Method for Evaluation of Uncertainties of ITS-90 by Standard Platinum Resistance Thermometer

Science.gov (United States)

Palenčár, Rudolf; Sopkuliak, Peter; Palenčár, Jakub; Ďuriš, Stanislav; Suroviak, Emil; Halaj, Martin

2017-06-01

Evaluation of uncertainties of the temperature measurement by standard platinum resistance thermometer calibrated at the defining fixed points according to ITS-90 is a problem that can be solved in different ways. The paper presents a procedure based on the propagation of distributions using the Monte Carlo method. The procedure employs generation of pseudo-random numbers for the input variables of resistances at the defining fixed points, supposing the multivariate Gaussian distribution for input quantities. This allows taking into account the correlations among resistances at the defining fixed points. Assumption of Gaussian probability density function is acceptable, with respect to the several sources of uncertainties of resistances. In the case of uncorrelated resistances at the defining fixed points, the method is applicable to any probability density function. Validation of the law of propagation of uncertainty using the Monte Carlo method is presented on the example of specific data for 25 Ω standard platinum resistance thermometer in the temperature range from 0 to 660 °C. Using this example, we demonstrate suitability of the method by validation of its results.

Methods of measuring floor resistance; Messverfahren zur Bestimmung des Ableitwiderstandes von Fussboeden

Energy Technology Data Exchange (ETDEWEB)

Seemann, A. [BGFW Berufsgenossenschaft der Gas-, Fernwaerme- und Wasserwirtschaft, Duesseldorf (Germany); Tutschek, G.; Warszewski, P. [Ruhrgas AG, Essen (Germany). Abt. Anlagensicherheit

2001-04-01

In gas fitting plants where explosive gas/air mixtures can occur the flooring materials must be conductive. Persons who are insulated from earth can easily acquire and retain an electrostatic charge. If an electrostatically charged person touches a conducting object (e.g. pipe, gas fitting plant) a spark occur at the point of contact. Such sparks can cause ignition of an explosive gas/air mixture. To avoid the retention of static electricity the recommended level of the earth of a floor must be lower than 10{sup 8} {omega} and the persons have to wear dissipative footwear. In several standards methods for checking floor resistance are described. A useful test method is given in DIN EN 1081. (orig.) [German] Explosionsfaehige Erdgas-/Luftgemische koennen durch elektrostatische Entladungsfunken gezuendet werden. Um eine elektrostatische Aufladung von Personen zu vermeiden, darf der Ableitwiderstand des Fussbodens den Wert von 10{sup 8} {omega} nicht ueberschreiten, und es muss ableitfaehiges Schuhwerk getragen werden. In verschiedenen Normen sind Messerfahren fuer die Ueberpruefung des Ableitwiderstandes von verlegten Fussboeden angegeben. Eine fuer die Praxis brauchbare Messmethode wird in DIN EN 1081 angegeben. (orig.)

Error free physically unclonable function with programmed resistive random access memory using reliable resistance states by specific identification-generation method

Science.gov (United States)

Tseng, Po-Hao; Hsu, Kai-Chieh; Lin, Yu-Yu; Lee, Feng-Min; Lee, Ming-Hsiu; Lung, Hsiang-Lan; Hsieh, Kuang-Yeu; Chung Wang, Keh; Lu, Chih-Yuan

2018-04-01

A high performance physically unclonable function (PUF) implemented with WO3 resistive random access memory (ReRAM) is presented in this paper. This robust ReRAM-PUF can eliminated bit flipping problem at very high temperature (up to 250 °C) due to plentiful read margin by using initial resistance state and set resistance state. It is also promised 10 years retention at the temperature range of 210 °C. These two stable resistance states enable stable operation at automotive environments from -40 to 125 °C without need of temperature compensation circuit. The high uniqueness of PUF can be achieved by implementing a proposed identification (ID)-generation method. Optimized forming condition can move 50% of the cells to low resistance state and the remaining 50% remain at initial high resistance state. The inter- and intra-PUF evaluations with unlimited separation of hamming distance (HD) are successfully demonstrated even under the corner condition. The number of reproduction was measured to exceed 107 times with 0% bit error rate (BER) at read voltage from 0.4 to 0.7 V.

Method for making low-resistivity contacts to high T/sub c/ superconductors

International Nuclear Information System (INIS)

Ekin, J.W.; Panson, A.J.; Blankenship, B.A.

1988-01-01

A method for making low-resistivity contacts to high T/sub c/ superconductors has been developed, which has achieved contact surface resistivities less than 10 μΩ cm 2 at 76 K and does not require sample heating above ∼150 0 C. This is an upper limit for the contact resistivity obtained at high current densities up to 10 2 --10 3 A/cm 2 across the contact interface. At lower measuring current densities the contact resistivities were lower and the voltage-current curve was nonlinear, having a superconducting transition character. On cooling from 295 to 76 K, the contact resistivity decreased several times, in contrast to indium solder contacts where the resistivity increased on cooling. The contacts showed consistently low resistivity and little degradation when exposed to dry air over a four-month period and when repeatedly cycled between room temperature and 76 K. The contacts are formed by sputter depositing a layer of a noble metal-silver and gold were used-on a clean superconductor surface to protect the surface and serve as a contact pad. External connections to the contact pads have been made using both solder and wire-bonding techniques

Standard test methods for performance characteristics of metallic bonded resistance strain gages

CERN Document Server

American Society for Testing and Materials. Philadelphia

1992-01-01

1.1 The purpose of this standard is to provide uniform test methods for the determination of strain gauge performance characteristics. Suggested testing equipment designs are included. 1.2 Test Methods E 251 describes methods and procedures for determining five strain gauge parameters: Section Part I—General Requirements 7 Part II—Resistance at a Reference Temperature 8 Part III—Gauge Factor at a Reference Temperature 9 Part IV—Temperature Coefficient of Gauge Factor\t10 Part V—Transverse Sensitivity\t11 Part VI—Thermal Output\t12 1.3 Strain gauges are very sensitive devices with essentially infinite resolution. Their response to strain, however, is low and great care must be exercised in their use. The performance characteristics identified by these test methods must be known to an acceptable accuracy to obtain meaningful results in field applications. 1.3.1 Strain gauge resistance is used to balance instrumentation circuits and to provide a reference value for measurements since all data are...

Automatic control and detector for three-terminal resistance measurement

Science.gov (United States)

Fasching, George E.

1976-10-26

A device is provided for automatic control and detection in a three-terminal resistance measuring instrument. The invention is useful for the rapid measurement of the resistivity of various bulk material with a three-terminal electrode system. The device maintains the current through the sample at a fixed level while measuring the voltage across the sample to detect the sample resistance. The three-electrode system contacts the bulk material and the current through the sample is held constant by means of a control circuit connected to a first of the three electrodes and works in conjunction with a feedback controlled amplifier to null the voltage between the first electrode and a second electrode connected to the controlled amplifier output. An A.C. oscillator provides a source of sinusoidal reference voltage of the frequency at which the measurement is to be executed. Synchronous reference pulses for synchronous detectors in the control circuit and an output detector circuit are provided by a synchronous pulse generator. The output of the controlled amplifier circuit is sampled by an output detector circuit to develop at an output terminal thereof a D.C. voltage which is proportional to the sample resistance R. The sample resistance is that segment of the sample between the area of the first electrode and the third electrode, which is connected to ground potential.

In vivo measurement of vocal fold surface resistance.

Science.gov (United States)

Mizuta, Masanobu; Kurita, Takashi; Dillon, Neal P; Kimball, Emily E; Garrett, C Gaelyn; Sivasankar, M Preeti; Webster, Robert J; Rousseau, Bernard

2017-10-01

A custom-designed probe was developed to measure vocal fold surface resistance in vivo. The purpose of this study was to demonstrate proof of concept of using vocal fold surface resistance as a proxy of functional tissue integrity after acute phonotrauma using an animal model. Prospective animal study. New Zealand White breeder rabbits received 120 minutes of airflow without vocal fold approximation (control) or 120 minutes of raised intensity phonation (experimental). The probe was inserted via laryngoscope and placed on the left vocal fold under endoscopic visualization. Vocal fold surface resistance of the middle one-third of the vocal fold was measured after 0 (baseline), 60, and 120 minutes of phonation. After the phonation procedure, the larynx was harvested and prepared for transmission electron microscopy. In the control group, vocal fold surface resistance values remained stable across time points. In the experimental group, surface resistance (X% ± Y% relative to baseline) was significantly decreased after 120 minutes of raised intensity phonation. This was associated with structural changes using transmission electron microscopy, which revealed damage to the vocal fold epithelium after phonotrauma, including disruption of the epithelium and basement membrane, dilated paracellular spaces, and alterations to epithelial microprojections. In contrast, control vocal fold specimens showed well-preserved stratified squamous epithelia. These data demonstrate the feasibility of measuring vocal fold surface resistance in vivo as a means of evaluating functional vocal fold epithelial barrier integrity. Device prototypes are in development for additional testing, validation, and for clinical applications in laryngology. NA Laryngoscope, 127:E364-E370, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Absolute coronary blood flow measurement and microvascular resistance in ST-elevation myocardial infarction in the acute and subacute phase

Energy Technology Data Exchange (ETDEWEB)

Wijnbergen, Inge; Veer, Marcel van ' t [Department of Cardiology, Catharina Hospital, Eindhoven (Netherlands); Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven (Netherlands); Lammers, Jeroen; Ubachs, Joey [Department of Cardiology, Catharina Hospital, Eindhoven (Netherlands); Pijls, Nico H.J., E-mail: nico.pijls@cze.nl [Department of Cardiology, Catharina Hospital, Eindhoven (Netherlands); Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven (Netherlands)

2016-03-15

Background/Purpose: In a number of patients with acute myocardial infarction (AMI), myocardial hypoperfusion, known as the no-reflow phenomenon, persists after primary percutaneous intervention (PPCI). The aim of this study was to evaluate the feasibility and safety of a new quantitative method of measuring absolute blood flow and resistance within the perfusion bed of an infarct-related artery. Furthermore, we sought to study no-reflow by correlating these measurements to the index of microvascular resistance (IMR) and the area at risk (AR) as determined by cardiac magnetic resonance imaging (CMR). Methods: Measurements of absolute flow and myocardial resistance were performed in 20 patients with ST-segment elevation myocardial infarction (STEMI), first immediately following PPCI and then again after 3–5 days. These measurements used the technique of thermodilution during a continuous infusion of saline. Flow was expressed in ml/min per gram of tissue within the area at risk. Results: The average time needed for measurement of absolute flow, resistance and IMR was 20 min, and all measurements could be performed without complication. A higher flow supplying the AR correlated with a lower IMR in the acute phase. Absolute flow increased from 3.14 to 3.68 ml/min/g (p = 0.25) and absolute resistance decreased from 1317 to 1099 dyne.sec.cm-5/g (p = 0.40) between the first day and fifth day after STEMI. Conclusions: Measurement of absolute flow and microvascular resistance is safe and feasible in STEMI patients and may allow for a better understanding of microvascular (dys)function in the early phase of AMI. - Highlights: • We measured absolute coronary blood flow and microvascular resistance in STEMI patients in the acute phase and in the subacute phase, using the technique of thermodilution with low grade intracoronary continuous infusion of saline. • These measurements are safe and feasible during PPCI in STEMI patients. • In STEMI patients, absolute flow

Sensitivity of resistive and Hall measurements to local inhomogeneities

DEFF Research Database (Denmark)

Koon, Daniel W.; Wang, Fei; Petersen, Dirch Hjorth

2014-01-01

We derive exact, analytic expressions for the sensitivity of sheet resistance and Hall sheet resistance measurements to local inhomogeneities for the cases of nonzero magnetic fields, strong perturbations, and perturbations over a finite area, extending our earlier results on weak perturbations. ...... simulations on both a linear four-point probe array on a large circular disc and a van der Pauw square geometry. Furthermore, the results also agree well with Náhlík et al. published experimental results for physical holes in a circular copper foil disc.......We derive exact, analytic expressions for the sensitivity of sheet resistance and Hall sheet resistance measurements to local inhomogeneities for the cases of nonzero magnetic fields, strong perturbations, and perturbations over a finite area, extending our earlier results on weak perturbations. We...

Resistive Wall Growth Rate Measurements in the Fermilab Recycler

Energy Technology Data Exchange (ETDEWEB)

Ainsworth, R. [Fermilab; Adamson, P. [Fermilab; Burov, A. [Fermilab; Kourbanis, I. [Fermilab

2016-10-05

Impedance could represent a limitation of running high intensity beams in the Fermilab recycler. With high intensity upgrades foreseen, it is important to quantify the impedance. To do this,studies have been performed measuring the growth rate of presumably the resistive wall instability. The growth rates at varying intensities and chromaticities are shown. The measured growth rates are compared to ones calculated with the resistive wall impedance.

Design and Construction of a Thermal Contact Resistance and Thermal Conductivity Measurement System

Science.gov (United States)

2015-09-01

thank my Mom, Dad , Allison, Jessica, and father-in-law, Tom, for always being there to listen and encourage me. xxiv THIS PAGE INTENTIONALLY...thermal conductivity is temperature measurement inaccuracies. A probe constructed of a poor thermally conductive material when inserted into a hot...interface- resistance-measurement-using-a-transient-method/ [26] H. Fukushima, L. T. Drzal, B. P. Rook and M. J. Rich , “Thermal conductivity of exfoliated

Evaluation of thermal resistance constitution for packaged AlGaN/GaN high electron mobility transistors by structure function method

International Nuclear Information System (INIS)

Zhang Guang-Chen; Feng Shi-Wei; Zhou Zhou; Li Jing-Wan; Guo Chun-Sheng

2011-01-01

The evaluation of thermal resistance constitution for packaged AlGaN/GaN high electron mobility transistor (HEMT) by structure function method is proposed in this paper. The evaluation is based on the transient heating measurement of the AlGaN/GaN HEMT by pulsed electrical temperature sensitive parameter method. The extracted chip-level and package-level thermal resistances of the packaged multi-finger AlGaN/GaN HEMT with 400-μm SiC substrate are 22.5 K/W and 7.2 K/W respectively, which provides a non-invasive method to evaluate the chip-level thermal resistance of packaged AlGaN/GaN HEMTs. It is also experimentally proved that the extraction of the chip-level thermal resistance by this proposed method is not influenced by package form of the tested device and temperature boundary condition of measurement stage. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

A method for detection and location of high resistance earth faults

Energy Technology Data Exchange (ETDEWEB)

Haenninen, S; Lehtonen, M [VTT Energy, Espoo (Finland); Antila, E [ABB Transmit Oy (Finland)

1998-08-01

In the first part of this presentation, the theory of earth faults in unearthed and compensated power systems is briefly presented. The main factors affecting the high resistance fault detection are outlined and common practices for earth fault protection in present systems are summarized. The algorithms of the new method for high resistance fault detection and location are then presented. These are based on the change of neutral voltage and zero sequence currents, measured at the high voltage / medium voltage substation and also at the distribution line locations. The performance of the method is analyzed, and the possible error sources discussed. Among these are, for instance, switching actions, thunder storms and heavy snow fall. The feasibility of the method is then verified by an analysis based both on simulated data, which was derived using an EMTP-ATP simulator, and by real system data recorded during field tests at three substations. For the error source analysis, some real case data recorded during natural power system events, is also used

Measured anisotropic air flow resistivity and sound attenuation of glass wool

DEFF Research Database (Denmark)

Tarnow, Viggo

2002-01-01

Department of Mechanical Engineering, Technical University of Denmark, Bygning 358, DK 2800 Lyngby, Denmark The air flow resistivity of glass wool has been measured in different directions. The glass wool was delivered from the manufacturer as slabs measuring 100×600×900 mm3, where the surface 600...... 7.75 kPa s m**2. A formula for prediction of resistivity for other densities is given. By comparing measured values of sound attenuation with results calculated from resistivity data, it is demonstrated that the measured attenuation can be predicted in a simple manner. ©2002 Acoustical Society...

Precision rectifier detectors for ac resistance bridge measurements with application to temperature control systems for irradiation creep experiments

Energy Technology Data Exchange (ETDEWEB)

Duncan, M. G.

1977-05-01

The suitability of several temperature measurement schemes for an irradiation creep experiment is examined. It is found that the specimen resistance can be used to measure and control the sample temperature if compensated for resistance drift due to radiation and annealing effects. A modified Kelvin bridge is presented that allows compensation for resistance drift by periodically checking the sample resistance at a controlled ambient temperature. A new phase-insensitive method for detecting the bridge error signals is presented. The phase-insensitive detector is formed by averaging the magnitude of two bridge voltages. Although this method is substantially less sensitive to stray reactances in the bridge than conventional phase-sensitive detectors, it is sensitive to gain stability and linearity of the rectifier circuits. Accuracy limitations of rectifier circuits are examined both theoretically and experimentally in great detail. Both hand analyses and computer simulations of rectifier errors are presented. Finally, the design of a temperature control system based on sample resistance measurement is presented. The prototype is shown to control a 316 stainless steel sample to within a 0.15/sup 0/C short term (10 sec) and a 0.03/sup 0/C long term (10 min) standard deviation at temperatures between 150 and 700/sup 0/C. The phase-insensitive detector typically contributes less than 10 ppM peak resistance measurement error (0.04/sup 0/C at 700/sup 0/C for 316 stainless steel or 0.005/sup 0/C at 150/sup 0/C for zirconium).

Testing the plant pneumatic method to estimate xylem embolism resistance in stems of temperate trees

OpenAIRE

Zhang, Ya; Lamarque, Laurent J.; Torres-Ruiz, José Manuel; Schuldt, Bernhard; Karimi, Zohreh; Li, Shan; Qin, De-Wen; Bittencourt, Paulo; Burlett, Régis; Cao, Kun-Fang; Delzon, Sylvain; Oliveira, Rafael; Pereira, Luciano; Jansen, Steven

2018-01-01

Methods to estimate xylem embolism resistance generally rely on hydraulic measurements, which can be far from straightforward. Recently, a pneumatic method based on air flow measurements of terminal branch ends was proposed to construct vulnerability curves by linking the amount of air extracted from a branch with the degree of embolism. We applied this novel technique for 10 temperate tree species, including six diffuse, two ring-porous and two gymnosperm species, and compared the pneumatic ...

Impact Strength of Natural Fibre Composites Measured by Different Test Methods: A Review

Directory of Open Access Journals (Sweden)

Navaranjan Namasivayam

2017-01-01

Full Text Available Different types of impact test methods have been used in recent years to measure the impact resistance of natural fibre composites (NFCs. After reviewing the literature, the impact resistance of flax, hemp, sisal, wood and jute fibre composites that were measured using different test methods have been compared and discussed. It has been learned that the test methods were selected for research interest, industry requirement or availability of test equipment. Each method had its own advantages and limitations. The result from a particular test could be compared but not with the result from other test methods. Most impact test methods were developed for testing ductile-brittle transition of metals. However, each NFC has a different morphology and cannot be comparable to metals in failure mode and energy absorption characteristic during an impact test. A post evaluation of morphology of an NFC sample after an impact test is important to characterise the material.

Measuring Learning Resistance to Workplace Training

Science.gov (United States)

Taylor, Jonathan E.; Lounsbury, John

2016-01-01

Training Transfer has been a topic bearing considerable mention over the past several decades. This article focuses on the connection between training transfer and learning resistance and presents research findings describing the design, creation, and testing of the Learning Efficiency Inventory (LEI). The LEI was designed to measure learning…

Determination of slope failure using 2-D resistivity method

Science.gov (United States)

Muztaza, Nordiana Mohd; Saad, Rosli; Ismail, Nur Azwin; Bery, Andy Anderson

2017-07-01

Landslides and slope failure may give negative economic effects including the cost to repair structures, loss of property value and medical costs in the event of injury. To avoid landslide, slope failure and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. Slope failure classification and various factors contributing to the instability using 2-D resistivity survey conducted in Selangor, Malaysia are described. The study on landslide and slope failure was conducted at Site A and Site B, Selangor using 2-D resistivity method. The implications of the anticipated ground conditions as well as the field observation of the actual conditions are discussed. Nine 2-D resistivity survey lines were conducted in Site A and six 2-D resistivity survey lines with 5 m minimum electrode spacing using Pole-dipole array were performed in Site B. The data were processed using Res2Dinv and Surfer10 software to evaluate the subsurface characteristics. 2-D resistivity results from both locations show that the study areas consist of two main zones. The first zone is alluvium or highly weathered with the resistivity of 100-1000 Ωm at 20-70 m depth. This zone consists of saturated area (1-100 Ωm) and boulders with resistivity value of 1200-3000 Ωm. The second zone with resistivity values of > 3000 Ωm was interpreted as granitic bedrock. The study area was characterized by saturated zones, highly weathered zone, highly contain of sand and boulders that will trigger slope failure in the survey area. Based on the results obtained from the study findings, it can be concluded that 2-D resistivity method is useful method in determination of slope failure.

Technique of Critical Current Density Measurement of Bulk Superconductor with Linear Extrapolation Method

International Nuclear Information System (INIS)

Adi, Wisnu Ari; Sukirman, Engkir; Winatapura, Didin S.

2000-01-01

Technique of critical current density measurement (Jc) of HTc bulk ceramic superconductor has been performed by using linear extrapolation with four-point probes method. The measurement of critical current density HTc bulk ceramic superconductor usually causes damage in contact resistance. In order to decrease this damage factor, we introduce extrapolation method. The extrapolating data show that the critical current density Jc for YBCO (123) and BSCCO (2212) at 77 K are 10,85(6) Amp.cm - 2 and 14,46(6) Amp.cm - 2, respectively. This technique is easier, simpler, and the use of the current flow is low, so it will not damage the contact resistance of the sample. We expect that the method can give a better solution for bulk superconductor application. Key words. : superconductor, critical temperature, and critical current density

Optimization of Drilling Resistance Measurement (DRM) user-controlled variables

OpenAIRE

Tudor, Dumitrescu; Pesce, Giovanni; Ball, Richard

2017-01-01

Drilling Resistance Measurement (DRM) is recognised as an important on-site micro-invasive procedure for assessment of construction materials. This paper presents a detailed investigation of user-controlled variables and their influence on drilling resistance. The study proves that the ratio of penetration rate/rotational speed (PR/RPM) is proportional to drilling resistance. Data from Bath stone and an artificial reference stone demonstrates how different materials can be compared using thei...

Increasing trend of community-acquired methicillin-resistant: Staphylococcal carriers: An alarming bell for urgent measures

Directory of Open Access Journals (Sweden)

Poongodi Lakshmi Santhana Kumarasamy

2015-01-01

Full Text Available Background: An increase in the incidence of infections caused by community-associated-methicillin resistant Staphylococcus aureus (MRSA has been reported. Hence, the knowledge of resistance pattern of these isolates is a precondition for alleviating emerging antibiotic resistance and devising better treatment strategies Aim: To find out the prevalence of community-acquired methicillin-resistant staphylococcal strains from nasal carriers. Materials and Methods: A total of 352 nasal swabs collected during routine health checkup were analyzed. Results: Of the 58 (16% staphylococci isolated, 32 (55% were S. aureus and 26 (45% were coagulase-negative staphylococci (CoNS. Methicillin resistance was observed in 7 (22% of staphylococci aureus and 11 (42% of CoNS. "D test" was positive in 1 (14% MRSA, 2 (8% methicillin-susceptible S. aureus and 2 (8% methicillin resistant-CoNS. Conclusion: Effective implementation of the antibiotic policy along with measures like hand wash, isolation of patients will reduce the incidence of resistance.

Estimating Penetration Resistance in Agricultural Soils of Ardabil Plain Using Artificial Neural Network and Regression Methods

Directory of Open Access Journals (Sweden)

Gholam Reza Sheykhzadeh

2017-02-01

Full Text Available Introduction: Penetration resistance is one of the criteria for evaluating soil compaction. It correlates with several soil properties such as vehicle trafficability, resistance to root penetration, seedling emergence, and soil compaction by farm machinery. Direct measurement of penetration resistance is time consuming and difficult because of high temporal and spatial variability. Therefore, many different regressions and artificial neural network pedotransfer functions have been proposed to estimate penetration resistance from readily available soil variables such as particle size distribution, bulk density (Db and gravimetric water content (θm. The lands of Ardabil Province are one of the main production regions of potato in Iran, thus, obtaining the soil penetration resistance in these regions help with the management of potato production. The objective of this research was to derive pedotransfer functions by using regression and artificial neural network to predict penetration resistance from some soil variations in the agricultural soils of Ardabil plain and to compare the performance of artificial neural network with regression models. Materials and methods: Disturbed and undisturbed soil samples (n= 105 were systematically taken from 0-10 cm soil depth with nearly 3000 m distance in the agricultural lands of the Ardabil plain ((lat 38°15' to 38°40' N, long 48°16' to 48°61' E. The contents of sand, silt and clay (hydrometer method, CaCO3 (titration method, bulk density (cylinder method, particle density (Dp (pychnometer method, organic carbon (wet oxidation method, total porosity(calculating from Db and Dp, saturated (θs and field soil water (θf using the gravimetric method were measured in the laboratory. Mean geometric diameter (dg and standard deviation (σg of soil particles were computed using the percentages of sand, silt and clay. Penetration resistance was measured in situ using cone penetrometer (analog model at 10

A new inductive method for measuring the RRR-value of niobium

International Nuclear Information System (INIS)

Bolore, M.; Bonin, B.; Boudigou, Y.; Heuveline, S.; Jacques, E.; Jaidane, S.; Koechlin, F.; Safa, H.

1996-01-01

A new method for measuring the RRR-value of niobium is presented. The principle of the measurement uses low frequency induction in a niobium sheet placed close to a pair of coils. In contrast with the usual resistive method, the present one gives information on the local value of the RRR, with a spatial resolution of the order of 1 cm. In addition, it is non destructive, thus opening the way to mapping RRR measurements on cavities. This tool will permit the measure of RRR inhomogeneities in cavities due to sheet forming or heat treatments, and the systematic check of the quality of weld seams. (author)

Recent developments in the use of temperature, resistivity and self-potential methods for monitoring embankment dam performance

Energy Technology Data Exchange (ETDEWEB)

Sheffer, M.R. [BC Hydro, Vancouver, BC (Canada); Johansson, S.; Sjodahl, P. [HydroResearch AB, Taby (Sweden)

2009-07-01

Significant research is being undertaken in the application and development of non-intrusive geophysical techniques as a result of the need for more comprehensive surveillance to detect internal erosion in embankment dams. Seepage and piezometric measurements are the most common methods utilized for dam surveillance. However, the spatial resolution of these measurements is generally not refined enough to detect small, local seepage changes. This paper summarized the current state of the art in the application of temperature, electrical resistivity and self-potential methods to seepage monitoring at embankment dam sites. The paper presented recent developments in using the technique and interpreting seepage parameters for each method. The methods were discussed in the context of both investigation and monitoring applications. It was concluded that the resistivity method is a non-destructive method that is well suited to long-term monitoring and has the ability to cover the entire dam. 25 refs., 11 figs.

Evaluation of the Mechanical Properties of Gray Cast Iron Using Electrical Resistivity Measurement

Directory of Open Access Journals (Sweden)

Bieroński M.

2016-12-01

Full Text Available In this paper an attempt to determine the relationship between the electrical resistivity and the tensile strength and hardness of cast iron of carbon equivalent in the range from 3.93% to 4.48%. Tests were performed on the gray cast iron for 12 different melts with different chemical composition. From one melt poured 6 samples. Based on the study of mechanical and electro-resistive determined variation characteristics of tensile strength, hardness and resistivity as a function of the carbon equivalent. Then, regression equations were developed as power functions describing the relationship between the resistivity of castings and their tensile strength and hardness. It was found a high level of regression equations to measuring points, particularly with regard to the relationship Rm=f(ρ. The obtained preliminary results indicate the possibility of application of the method of the resistance to rapid diagnostic casts on the production line, when we are dealing with repeatable production, in this case non variable geometry of the product for which it has been determinated before a regression equation.

Intra and interobserver variability of renal allograft ultrasound volume and resistive index measurements

International Nuclear Information System (INIS)

Mancini, Marcello; Liuzzi, Raffaele; Daniele, Stefania; Raffio, Teresa; Salvatore, Marco; Sabbatini, Massimo; Cianciaruso, Bruno; Ferrara, Liberato Aldo

2005-01-01

Purpose: Aim of the presents study was to evaluate the repeatability and reproducibility of the Doppler Resistive Index (R.I.) and the Ultrasound renal volume measurement in renal transplants. Materials and methods: Twenty -six consecutive patients (18 men, 8 women) mean age of 42,8±12,4 years (M±SD)(range 22-65 years) were studied twice by each of two trained sonographers using a color Doppler ultrasound scanner. Twelve of them had a normal allograft function (defined as stable serum creatinine levels ≤123,76 μmol/L), whilst the remaining 14 had decreased allograft function (serum creatinine 132.6-265.2 μmol/L). Results were given as mean of 6 measurements performed at upper, middle and lower pole of the kidney. Intra- and interobserver variability was assessed by the repeatability coefficient and coefficient of variation (CV). Results: Regarding Resistive Index measurement, repeatability coefficient was between 0.04 and 0.06 and the coefficient of variation was [it

Ringtest to evaluate four methods of resistance testing in fodder radish against Meloidogyne chitwoodi

NARCIS (Netherlands)

Visser, J.H.M.; Berg, van den W.; Korthals, G.W.

2009-01-01

To measure levels of resistance in fodder radish cultivars a reliable, objective and cost effective testing method is required. In 2006 German and Dutch plant breeder’s organizations (Bundesverband Deutscher Pflanzenzüchter; BDP and Plantum), a number of research institutes (PRI, PPO (WUR) and JKI)

Development of a Real-Time Resistance Measurement for Vibrio parahaemolyticus Detection by the Lecithin-Dependent Hemolysin Gene

Science.gov (United States)

Xiang, Guiming; Pu, Xiaoyun; Jiang, Dongneng; Liu, Linlin; Liu, Chang; Liu, Xiaobo

2013-01-01

The marine bacterium Vibrio parahaemolyticus (V. parahaemolyticus) causes gastroenteritis in humans via the ingestion of raw or undercooked contaminated seafood, and early diagnosis and prompt treatment are important for the prevention of V. parahaemolyticus-related diseases. In this study, a real-time resistance measurement based on loop-mediated isothermal amplification (LAMP), electrochemical ion bonding (Crystal violet and Mg2+), real-time monitoring, and derivative analysis was developed. V. parahaemolyticus DNA was first amplified by LAMP, and the products (DNA and pyrophosphate) represented two types of negative ions that could combine with a positive dye (Crystal violet) and positive ions (Mg2+) to increase the resistance of the reaction liquid. This resistance was measured in real-time using a specially designed resistance electrode, thus permitting the quantitative detection of V. parahaemolyticus. The results were obtained in 1–2 hours, with a minimum bacterial density of 10 CFU.mL−1 and high levels of accuracy (97%), sensitivity (96.08%), and specificity (97.96%) when compared to cultivation methods. Therefore, this simple and rapid method has a potential application in the detection of V. parahaemolyticus on a gene chip or in point-of-care testing. PMID:23991096

Loss-resistant unambiguous phase measurement

OpenAIRE

Dinani, Hossein T.; Berry, Dominic W.

2014-01-01

Entangled multi-photon states have the potential to provide improved measurement accuracy, but are sensitive to photon loss. It is possible to calculate ideal loss-resistant states that maximize the Fisher information, but it is unclear how these could be experimentally generated. Here we propose a set of states that can be obtained by processing the output from parametric down-conversion. Although these states are not optimal, they provide performance very close to that of optimal states for...

Design and evaluation of a low thermal electromotive force guarded scanner for resistance measurements

Science.gov (United States)

Jarrett, Dean G.; Marshall, James A.; Marshall, Thomas A.; Dziuba, Ronald F.

1999-06-01

The design and testing of a low thermal electromotive force guarded scanner, developed to provide completely guarded switching when used with actively guarded resistance bridge networks, is described. The design provides a continuous guard circuit trace on the scanner circuit boards that surrounds the relay contacts and protects the measurement circuit from leakages to ground. Modification to the circuit boards and relays of the guarded scanner are explained. Several tests were developed to evaluate the guarding effectiveness, including isolating sections of the guard circuit to create a potential drop between the main and guard circuits. Calibration of standard resistors using the guarded scanner has shown relative differences less than 1×10-6, 30×10-6, and 150×10-6 for measurements made with and without the guarded scanner at nominal resistances of 1, 10, and 100 GΩ, respectively. The substitution method was used to significantly reduce the relative differences between channels to less than 0.5×10-6, 3×10-6, and 30×10-6 for nominal resistances of 1, 10, and 100 GΩ, respectively. Applications for the guarded scanner in automated direct current measurement systems are presented.

Measuring Resistance to Change at the Within-Session Level

Science.gov (United States)

Tonneau, Francois; Rios, Americo; Cabrera, Felipe

2006-01-01

Resistance to change is often studied by measuring response rate in various components of a multiple schedule. Response rate in each component is normalized (that is, divided by its baseline level) and then log-transformed. Differential resistance to change is demonstrated if the normalized, log-transformed response rate in one component decreases…

XPS and surface resistivity measurements of plasma - treated FEP co-polymer

International Nuclear Information System (INIS)

Pitrus, R.K.; Brack, N.; Liesegang, J.; Pigram, P.J.

2002-01-01

Full text: Fluorinated polymers such as fluorinated ethylene propylene (FEP) and poly(tetrafluoroethylene) (PTFE) play an important role in many applications due to their many desirable properties such as chemical resistivity, inertness, electrical stability and low dielectric constant; however, one disadvantage of fluorinated polymers is their extreme surface hydrophobicity. Previous studies show that plasma treatment will modify the surface by increasing the surface free energy and also offer a rapid and convenient method for pre-treating the polymers for many purposes. This paper, through resistivity and XPS (x-ray photoelectron spectroscopy) measurements, attempts to discover basic effects of such plasma treatment. Fluorinated ethylene propylene (FEP) co-polymer film of (0.05) mm thickness (obtained commercially) and with the following structure (CF 2 -CF 2 )-(CF(CF 3 )CF 2 )- was used. A suitable cleaning procedure was used to remove adventitious carbon from the surface. XPS has been used to study FEP film properties. The spectra of XPS were analyzed with the main focus on carbon and fluorine as they compose the elemental component of FEP film. A value of 2.05 was obtained for the F/C ratio, which is slightly higher than the theoretical F/C value estimated from the chemical structure of FEP (F/C 2). The clean film was then air plasma treated (pressure 10 -1 torr and power 30W) for various treatment times to produce a higher energy fluoropolymer surface. XPS studies investigated changes to the polymer surface and determined that oxidation occurs on the FEP surface. The oxidation reactions on the FEP surface form oxygen functional groups such as C-O and C=O groups. The results also show that the percentage of CF 2 and CF 3 in the co-polymer surface decreased with exposure time and the percentage of CF, C-C, C-O and C=O increased. There is a sharp decrease in F/C ratio and increase in O/C ratio. In addition to XPS, the resistivity of FEP-film was measured by a

Delamination Detection in Carbon Fibre Reinforced Composites Using Electrical Resistance Measurement

International Nuclear Information System (INIS)

Kovalovs, A; Rucevskis, S; Kulakov, V; Aniskevich, A

2016-01-01

In the present study 2-D numerical analysis of strip-type laminated composite specimens with and without damage is considered and numerical investigation is carried out by using a finite element method. The surface and oblique resistances are numerically calculated according to the two-probe and four-probe methods. The electrical conductivity of the composite laminate in the longitudinal direction is constant, while the electrical conductivity in the through-thickness direction is used as a variable in the parametric study. The resistance change due to delamination for each case is estimated by comparing the obtained resistance with the corresponding resistance of the specimen without delamination. Applicability and effectiveness of the proposed method are investigated by using various lengths of a delaminated crack in the specimen. (paper)

Comparison of methods for measuring flux gradients in type II superconductors

International Nuclear Information System (INIS)

Kroeger, D.M.; Koch, C.C.; Charlesworth, J.P.

1975-01-01

A comparison has been made of four methods of measuring the critical current density J/sub c/ in hysteretic type II superconductors, having a wide range of K and J/sub c/ values, in magnetic fields up to 70 kOe. Two of the methods, (a) resistive measurements and (b) magnetization measurements, were carried out in static magnetic fields. The other two methods involved analysis of the response of the sample to a small alternating field superimposed on the static field. The response was analyzed either (c) by measuring the third-harmonic content or (d) by integration of the waveform to obtain measure of flux penetration. The results are discussed with reference to the agreement between the different techniques and the consistency of the critical state hypothesis on which all these techniques are based. It is concluded that flux-penetration measurements by method (d) provide the most detailed information about J/sub c/ but that one must be wary of minor failures of the critical state hypothesis. Best results are likely to be obtained by using more than one method. (U.S.)

Thermal resistance measurement of In{sub 3}SbTe{sub 2} nanowires

Energy Technology Data Exchange (ETDEWEB)

Battaglia, J.L.; Saci, A.; De, I. [I2M Laboratory, University of Bordeaux, UMR CNRS 5295, Talence (France); Cecchini, R.; Cecchi, S.; Longo, M. [Laboratorio MDM, IMM-CNR, Unita di Agrate Brianza (Italy); Selmo, S.; Fanciulli, M. [Laboratorio MDM, IMM-CNR, Unita di Agrate Brianza (Italy); Dipartimento di Scienza dei Materiali, University of Milano Bicocca, Milano (Italy)

2017-05-15

The thermal resistance along the thickness of In{sub 3}SbTe{sub 2} crystalline nanowires was measured using the scanning thermal microscopy in 3ω mode. The nanowires were grown by metal organic vapor deposition, exploiting the VLS mechanism induced by Au metal-catalyst nanoparticles and harvested on a SiO{sub 2}/Si substrate. Two nanowires with different thickness (13 and 23 nm) were investigated. The thermal resistance of the nanowires was determined using two different approaches; the first one exploits the experimental data, whereas the second one is more sophisticated, since it involves a minimization procedure. Both methods led to comparable values of the thermal resistance along the transverse direction (thickness) of the nanowire. The obtained results were explained starting from the mean free path of phonons calculated in the In{sub 3}SbTe{sub 2} bulk. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A setup for measuring the Seebeck coefficient and the electrical resistivity of bulk thermoelectric materials

Science.gov (United States)

Fu, Qiang; Xiong, Yucheng; Zhang, Wenhua; Xu, Dongyan

2017-09-01

This paper presents a setup for measuring the Seebeck coefficient and the electrical resistivity of bulk thermoelectric materials. The sample holder was designed to have a compact structure and can be directly mounted in a standard cryostat system for temperature-dependent measurements. For the Seebeck coefficient measurement, a thin bar-shaped sample is mounted bridging two copper bases; and two ceramic heaters are used to generate a temperature gradient along the sample. Two type T thermocouples are used to determine both temperature and voltage differences between two widely separated points on the sample. The thermocouple junction is flattened into a disk and pressed onto the sample surface by using a spring load. The flexible fixation method we adopted not only simplifies the sample mounting process but also prevents thermal contact deterioration due to the mismatch of thermal expansion coefficients between the sample and other parts. With certain modifications, the sample holder can also be used for four-probe electrical resistivity measurements. High temperature measurements are essential for thermoelectric power generation. The experimental system we developed is capable of measuring the Seebeck coefficient and the electrical resistivity of bulk thermoelectric materials in a wide temperature range from 80 to 500 K, which can be further extended to even higher temperatures. Measurements on two standard materials, constantan and nickel, confirmed the accuracy and the reliability of the system.

The electrical resistivity method in cased boreholes

Energy Technology Data Exchange (ETDEWEB)

Schenkel, C.J.

1991-05-01

The use of downhole current sources in resistivity mapping can greatly enhance the detection and delineation of subsurface features. The purpose of this work is to examine the resistivity method for current sources in wells cased with steel. The resistivity method in cased boreholes with downhole current sources is investigated using the integral equation (IE) technique. The casing and other bodies are characterized as conductivity inhomogeneities in a half-space. For sources located along the casing axis, an axially symmetric Green's function is used to formulate the surface potential and electric field (E-field) volume integral equations. The situations involving off-axis current sources and three-dimensional (3-D) bodies is formulated using the surface potential IE method. The solution of the 3-D Green's function is presented in cylindrical and Cartesian coordinate systems. The methods of moments is used to solve the Fredholm integral equation of the second kind for the response due to the casing and other bodies. The numerical analysis revealed that the current in the casing can be approximated by its vertical component except near the source and the axial symmetric approximation of the casing is valid even for the 3-D problem. The E-field volume IE method is an effective and efficient technique to simulate the response of the casing in a half-space, whereas the surface potential approach is computationally better when multiple bodies are involved. Analyzing several configurations of the current source indicated that the casing response is influenced by four characteristic factors: conduction length, current source depth,casing depth, and casing length. 85 refs., 133 figs., 11 tabs.

Comparison of two in vitro methods for the detection of ivermectin resistance in Haemonchus contortus in sheep

Directory of Open Access Journals (Sweden)

Urda Dolinská M.

2016-06-01

Full Text Available Gastrointestinal parasitic nematodes in sheep cause severe economic losses. Anthelmintics are the most commonly used drugs for prophylaxis and therapy against parasitic helminths. The problem of drug resistance has developed for all commercially available anthelmintics in several genera and classes of helminths. In vitro and in vivo tests are used to detect anthelmintic resistance. Two in vitro methods (larval migration inhibition test and micromotility test for the detection of ivermectin (IVM resistance were compared using IVM-resistant and IVM-susceptible isolates of Haemonchus contortus. The degree of resistance for each test was expressed as a resistance factor (RF. The micromotility test was more sensitive for quantitatively measuring the degree of resistance between susceptible and resistant isolates. The RFs for this test for IVM and eprinomectin ranged from 1.00 to 108.05 and from 3.87 to 32.32, respectively.

Microfluidic Device to Measure the Speed of C. elegans Using the Resistance Change of the Flexible Electrode

Directory of Open Access Journals (Sweden)

Jaehoon Jung

2016-03-01

Full Text Available This work presents a novel method to assess the condition of Caenorhabditis elegans (C. elegans through a resistance measurement of its undulatory locomotion speed inside a micro channel. As the worm moves over the electrode inside the micro channel, the length of the electrode changes, consequently behaving like a strain gauge. In this paper, the electrotaxis was applied for controlling the direction of motion of C. elegans as an external stimulus, resulting in the worm moving towards the cathode of the circuit. To confirm the proposed measurement method, a microfluidic device was developed that employs a sinusoidal channel and a thin polydimethylsiloxane (PDMS layer with an electrode. The PDMS layer maintains a porous structure to enable the flexibility of the electrode. In this study, 6 measurements were performed to obtain the speed of an early adult stage C. elegans, where the measured average speed was 0.35 (±0.05 mm/s. The results of this work demonstrate the application of our method to measure the speed of C. elegans undulatory locomotion. This novel approach can be applied to make such measurements without an imaging system, and more importantly, allows directly to detect the locomotion of C. elegans using an electrical signal (i.e., the change in resistance.

Instrument for measuring metal-thermoelectric semiconductor contact resistence

International Nuclear Information System (INIS)

Lanxner, M.; Nechmadi, M.; Meiri, B.; Schildkraut, I.

1979-02-01

An instrument for measuring electrical, metal-thermoelectric semiconductor contact resistance is described. The expected errors of measurement are indicated. The operation of the instrument which is based on potential traversing perpendicularly to the contact plane is illustrated for the case of contacts of palladium and bismuth telluride-based thermoelectric material

Carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool

International Nuclear Information System (INIS)

Cai, Yu; Sha, Shuang

2016-01-01

This paper proposes a new carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool used in a cylindrical borehole environment during oil-based mud drilling processes. The new tool is an orthogonal frequency division multiplexing access-based contactless multi-measurand detection tool. The tool can measure formation resistivity in different azimuthal angles and elevational depths. It can measure many more measurands simultaneously in a specified bandwidth than the legacy frequency division multiplexing multi-measurand tool without a channel-select filter while avoiding inter-carrier interference. The paper also shows that formation resistivity is not sensitive to frequency in certain frequency bands. The average resistivity collected from N subcarriers can increase the measurement of the signal-to-noise ratio (SNR) by N times given no amplitude clipping in the current-injection electrode. If the clipping limit is taken into account, with the phase rotation of each single carrier, the amplitude peak-to-average ratio can be reduced by 3 times, and the SNR can achieve a 9/ N times gain over the single-carrier system. The carrier-interleaving technique is also introduced to counter the carrier frequency offset (CFO) effect, where the CFO will cause inter-pad interference. A qualitative analysis and simulations demonstrate that block-interleaving performs better than tone-interleaving when coping with a large CFO. The theoretical analysis also suggests that increasing the subcarrier number can increase the measurement speed or enhance elevational resolution without sacrificing receiver performance. The complex orthogonal multi-pad multi-carrier resistivity logging tool, in which all subcarriers are complex signals, can provide a larger available subcarrier pool than other types of transceivers. (paper)

In-situ calibration of nuclear-plant platinum resistance thermometers using Johnson noise methods. Final report

International Nuclear Information System (INIS)

Blalock, T.V.; Shepard, R.L.

1983-06-01

Methods for in situ calibration of reactor plant platinum resistance thermometers using Johnson noise measurements were tested in the laboratory and in two operating reactors: Diablo Canyon and Sequoyah. The Johnson noise methods provide an absolute measurement of the thermometer temperature and can be compared with the dc calibration of the thermometers to confirm their calibration without removing the thermometers from the plant coolant loops. Inaccuracies of less than 0.1% were obtained with these methods for ideal situations where the noise measuring equipment could be connected directly to the installed thermometer terminals. For measurements made at the ends of long extension cables, inaccuracies were 0.5 to 1.0%, at best. Extension cables must be optimized and well characterized electrically to achieve such accuracies. Other factors that affect the accuracy of these methods were evaluated

Influence of plant roots on electrical resistivity measurements of cultivated soil columns

Science.gov (United States)

Maloteau, Sophie; Blanchy, Guillaume; Javaux, Mathieu; Garré, Sarah

2016-04-01

Electrical resistivity methods have been widely used for the last 40 years in many fields: groundwater investigation, soil and water pollution, engineering application for subsurface surveys, etc. Many factors can influence the electrical resistivity of a media, and thus influence the ERT measurements. Among those factors, it is known that plant roots affect bulk electrical resistivity. However, this impact is not yet well understood. The goals of this experiment are to quantify the effect of plant roots on electrical resistivity of the soil subsurface and to map a plant roots system in space and time with ERT technique in a soil column. For this research, it is assumed that roots system affect the electrical properties of the rhizosphere. Indeed the root activity (by transporting ions, releasing exudates, changing the soil structure,…) will modify the rhizosphere electrical conductivity (Lobet G. et al, 2013). This experiment is included in a bigger research project about the influence of roots system on geophysics measurements. Measurements are made on cylinders of 45 cm high and a diameter of 20 cm, filled with saturated loam on which seeds of Brachypodium distachyon (L.) Beauv. are sowed. Columns are equipped with electrodes, TDR probes and temperature sensors. Experiments are conducted at Gembloux Agro-Bio Tech, in a growing chamber with controlled conditions: temperature of the air is fixed to 20° C, photoperiod is equal to 14 hours, photosynthetically active radiation is equal to 200 μmol m-2s-1, and air relative humidity is fixed to 80 %. Columns are fully saturated the first day of the measurements duration then no more irrigation is done till the end of the experiment. The poster will report the first results analysis of the electrical resistivity distribution in the soil columns through space and time. These results will be discussed according to the plant development and other controlled factors. Water content of the soil will also be detailed

Evaluating parameterizations of aerodynamic resistance to heat transfer using field measurements

Directory of Open Access Journals (Sweden)

Shaomin Liu

2007-01-01

Full Text Available Parameterizations of aerodynamic resistance to heat and water transfer have a significant impact on the accuracy of models of land – atmosphere interactions and of estimated surface fluxes using spectro-radiometric data collected from aircrafts and satellites. We have used measurements from an eddy correlation system to derive the aerodynamic resistance to heat transfer over a bare soil surface as well as over a maize canopy. Diurnal variations of aerodynamic resistance have been analyzed. The results showed that the diurnal variation of aerodynamic resistance during daytime (07:00 h–18:00 h was significant for both the bare soil surface and the maize canopy although the range of variation was limited. Based on the measurements made by the eddy correlation system, a comprehensive evaluation of eight popularly used parameterization schemes of aerodynamic resistance was carried out. The roughness length for heat transfer is a crucial parameter in the estimation of aerodynamic resistance to heat transfer and can neither be taken as a constant nor be neglected. Comparing with the measurements, the parameterizations by Choudhury et al. (1986, Viney (1991, Yang et al. (2001 and the modified forms of Verma et al. (1976 and Mahrt and Ek (1984 by inclusion of roughness length for heat transfer gave good agreements with the measurements, while the parameterizations by Hatfield et al. (1983 and Xie (1988 showed larger errors even though the roughness length for heat transfer has been taken into account.

VARIABILITY OF FORCED OSCILLATION (SIEMENS SIREGNOST FD-5) MEASUREMENTS OF TOTAL RESPIRATORY RESISTANCE IN PATIENTS AND HEALTHY-SUBJECTS

NARCIS (Netherlands)

GIMENO, F; VANDERWEELE, LT; KOETER, GH; DEMONCHY, JGR; VANALTENA, R

The reproducibility of total respiratory resistance (R(rs)) measured with a simplified forced oscillatory method (Siemens Siregnost FD 5) was measured and compared with that of slow inspiratory vital capacity (IVC) and forced expiratory volume in one second (FEV1). The former technique has the

Validation of the method for determination of the thermal resistance of fouling in shell and tube heat exchangers

International Nuclear Information System (INIS)

Markowski, Mariusz; Trafczynski, Marian; Urbaniec, Krzysztof

2013-01-01

Highlights: • Heat recovery in a heat exchanger network (HEN). • A novel method for on-line determination of the thermal resistance of fouling is presented. • Details are developed for shell and tube heat exchangers. • The method was validated and sensibility analysis was carried out. • Developed approach allows long-term monitoring of changes in the HEN efficiency. - Abstract: A novel method for on-line determination of the thermal resistance of fouling in shell and tube heat exchangers is presented. It can be applied under the condition that the data on pressure, temperature, mass flowrate and thermophysical properties of both heat-exchanging media are continuously available. The calculation algorithm for use in the novel method is robust and ensures reliable determination of the thermal resistance of fouling even if the operating parameters fluctuate. The method was validated using measurement data retrieved from the operation records of a heat exchanger network connected with a crude distillation unit rated 800 t/h. Sensibility analysis of the method was carried out and the calculated values of the thermal resistance of fouling were critically reviewed considering the results of qualitative evaluation of fouling layers in the exchangers inspected during plant overhaul

Insulating and sheathing materials of electric and optical cables: common test methods part 4-1: methods specific to polyethylene and polypropylene compounds – resistance to environmental stress cracking – measurement of the melt flow index – carbon black and/or mineral filler content measurement in polyethylene by direct combustion – measurement of carbon black content by thermogravimetric analysis (TGA) – assessment of carbon black dispersion in polyethylene using a microscope

CERN Document Server

International Electrotechnical Commission. Geneva

2004-01-01

Specifies the test methods to be used for testing polymeric insulating and sheathing materials of electric cables for power distribution and telecommunications including cables used on ships. Gives the methods for measurements of the resistance to environmental stress cracking, for wrapping test after thermal ageing in air, for measurement of melt flow index and for measurement of carbon black and/or mineral filler content, which apply to PE and PP coumpounds, including cellular compounds and foam skin for insulation.

Airflow resistivity instrument for in situ measurement on the earth's ground surface

Science.gov (United States)

Zuckerwar, A. J.

1983-01-01

An airflow resistivity instrument features a novel specimen holder, especially designed for in situ measurement on the earth's ground surface. This capability eliminates the disadvantages of prior intrusive instruments, which necessitate the removal of a test specimen from the ground. A prototype instrument can measure airflow resistivities in the range 10-5000 cgs rayl/cm, at specimen depths up to 15.24 cm (6 in.), and at differential pressures up to 2490.8 dyn sq cm (1 in. H2O) across the specimen. Because of the close relationship between flow resistivity and acoustic impedance, this instrument should prove useful in acoustical studies of the earth's ground surface. Results of airflow resistivity measurements on an uncultivated grass field for varying values of moisture content are presented.

Synthesis and characterization of large WO{sub 3} sheets synthesized by resistive heating method

Energy Technology Data Exchange (ETDEWEB)

Filippo, Emanuela, E-mail: emanuela.filippo@unisalento.it [Department of Engineering for Innovation, University of Salento, Monteroni Street, Lecce I-73100 Italy (Italy); Tepore, Marco [Department of Engineering for Innovation, University of Salento, Monteroni Street, Lecce I-73100 Italy (Italy); Baldassarre, Francesca [Department of Cultural Heritage, University of Salento, Lecce I-73100 Italy (Italy); Quarta, Gianluca; Calcagnile, Lucio [Department of Engineering for Innovation, University of Salento, Monteroni Street, Lecce I-73100 Italy (Italy); Guascito, Maria Rachele [DiSTeBA, University of Salento, Lecce I-73100 Italy (Italy); Tepore, Antonio [Department of Cultural Heritage, University of Salento, Lecce I-73100 Italy (Italy)

2015-09-01

A simple, low-cost method is presented to grow tungsten oxide large sheets simply by resistively heating a pure tungsten filament under air/water vapor flow. The obtained structures were studied using scanning and transmission electron microscopy, selected area diffraction, X Ray diffraction, Raman and X-ray photoelectron spectroscopy, photoluminescence and zeta potential measurements. SEM observations revealed that sheets formed by broadening of the wires/belts over longer growth period. Photoluminescence measurements showed that tungsten oxide sheets had an intense visible emission band. - Highlights: • WO{sub 3} large sheets were prepared by resistively heating a W filament. • WO{sub 3} sheets were carefully characterized. • Formation mechanism of sheets was studied. • WO{sub 3} sheets had an intense visible emission band at 462 nm.

Effect of the interface resistance in non-local Hanle measurements

International Nuclear Information System (INIS)

Villamor, Estitxu; Hueso, Luis E.; Casanova, Fèlix

2015-01-01

We use lateral spin valves with varying interface resistance to measure non-local Hanle effect in order to extract the spin-diffusion length of the non-magnetic channel. A general expression that describes spin injection and transport, taking into account the influence of the interface resistance, is used to fit our results. Whereas the fitted spin-diffusion length value is in agreement with the one obtained from standard non-local measurements in the case of a finite interface resistance, in the case of transparent contacts a clear disagreement is observed. The use of a corrected expression, recently proposed to account for the anisotropy of the spin absorption at the ferromagnetic electrodes, still yields a deviation of the fitted spin-diffusion length which increases for shorter channel distances. This deviation shows how sensitive the non-local Hanle fittings are, evidencing the complexity of obtaining spin transport information from such type of measurements

Using Resistivity Measurements to Determine Anisotropy in Soil and Weathered Rock

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S. Soto-Caban

2013-08-01

Full Text Available This study uses electrical resistivity measurements of soils and weathered rock to perform a fast and reliable evaluation of field anisotropy. Two test sites at New Concord, Ohio were used for the study. These sites are characterized by different landform and slightly east dipping limestone and siltstone formations of Pennsylvanian age. The measured resistivity ranged from 19 Ω∙m to 100 ��∙m, and varied with depth, landform, and season. The anisotropy was determined by a comparison of resistance values along the directions of strike and the dip. Measurements showed that the orientation of electrical anisotropy in the shallow ground may vary due to fluid connection, which is determined by the pore geometry in soil and rock, as well as by the direction of fluid movement. Results from this study indicated that a portable electrical resistivity meter is sensitive and reliable enough to be used for shallow ground fluid monitoring.

Determination of a Wear Initiation Cycle by using a Contact Resistance Measurement in Nuclear Fuel Fretting

International Nuclear Information System (INIS)

Lee, Young Ho; Kim, Hyung Kyu

2008-01-01

In nuclear fuel fretting, the improving of the contact condition with a modified spring shape is a useful method for increasing the wear resistance of the nuclear fuel rod. This is because the fretting wear resistance between the fuel rod and grid spring is mainly affected by the grid spring shape rather than the environment, the contact modes, etc. In addition, the wear resistance is affected by the wear debris behavior between contact surfaces. So, it is expected that the wear initiation of each spring shape should be determined in order to evaluate a wear resistance. However, it is almost impossible to measure the wear behavior in contact surfaces on a real time basis because the contact surfaces are always hidden. Besides, the results of the worn surface observation after the fretting wear tests are restricted to archive the information on the wear debris behavior and the formation mechanism of the wear scar. In order to evaluate the wear behavior during the fretting wear tests, it is proposed that the contact resistance measurement is a useful method for examining the wear initiation cycle and modes. Generally, fretting wear damages are rapidly progressed by a localized plastic deformation between the contact surfaces, crack initiation and fracture of the deformed surface with a strain hardening difference between a surface and a subsurface and finally a detachment of wear debris. After this, wear debris is easily oxidized by frictional heat, test environment, etc. At this time, a small amount of electric current applied between the contact surfaces will be influenced by the wear debris, which could be an obstacle to an electric current flow. So, it is possible to archive the information on the wear behavior by measuring the contact resistance. In order to determine the wear initiation cycle during the fretting wear tests, in this study, fretting wear tests have been performed by applying a constant electric current in room temperature air

Electro-location, tomography and porosity measurements in geotechnical centrifuge models based on electrical resistivity concepts

Science.gov (United States)

Li, Zhihua

This research was focused on the development of electrical techniques for soil characterization and soil dynamic behavior assessment. The research carried out mainly includes (1) development of a needle probe tool for assessment of soil spatial variability in terms of porosity with high-resolution in the centrifuge testing; (2) development of an electro-location technique to accurately detect buried objects' movements inside the soil during dynamic events; (3) collaborative development of a new electrode switching system to implement electrical resistivity tomography, and electro-location with high speed and high resolution. To assess soil spatial variability with high-resolution, electrical needle probes with different tip shapes were developed to measure soil electrical resistivity. After normalizing soil resistivity by pore fluid resistivity, this information can be correlated to soil porosity. Calibrations in laboratory prepared soils were conducted. Loosening due to insertion of needle probes was evaluated. A special needle probe tool, along with data acquisition and data processing tools were developed to be operated by the new NEES robot on the centrifuge. The needle probes have great potential to resolve interfaces between soil layers and small local porosity variations with a spatial resolution approximately equal to the spacing between electrodes (about half of the probe diameter). A new electrode switching system was developed to accurately detect buried objects' movements using a new electro-location scheme. The idea was to establish an electromagnetic field in a centrifuge model by injecting low-frequency alternating currents through pairs of boundary electrodes. The locations of buried objects are related to the potentials measured on them. A closed form expression for the electric field in a rectangular specimen with insulated boundaries was obtained based on the method of images. Effects of sampling parameters on spatial resolution and tradeoffs

Loss-resistant unambiguous phase measurement

Science.gov (United States)

Dinani, Hossein T.; Berry, Dominic W.

2014-08-01

Entangled multiphoton states have the potential to provide improved measurement accuracy, but are sensitive to photon loss. It is possible to calculate ideal loss-resistant states that maximize the Fisher information, but it is unclear how these could be experimentally generated. Here we propose a set of states that can be obtained by processing the output from parametric down-conversion. Although these states are not optimal, they provide performance very close to that of optimal states for a range of parameters. Moreover, we show how to use sequences of such states in order to obtain an unambiguous phase measurement that beats the standard quantum limit. We consider the optimization of parameters in order to minimize the final phase variance, and find that the optimum parameters are different from those that maximize the Fisher information.

Wave resistance calculation method combining Green functions based on Rankine and Kelvin source

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LI Jingyu

2017-12-01

Full Text Available [Ojectives] At present, the Boundary Element Method(BEM of wave-making resistance mostly uses a model in which the velocity distribution near the hull is solved first, and the pressure integral is then calculated using the Bernoulli equation. However,the process of this model of wave-making resistance is complex and has low accuracy.[Methods] To address this problem, the present paper deduces a compound method for the quick calculation of ship wave resistance using the Rankine source Green function to solve the hull surface's source density, and combining the Lagally theorem concerning source point force calculation based on the Kelvin source Green function so as to solve the wave resistance. A case for the Wigley model is given.[Results] The results show that in contrast to the thin ship method of the linear wave resistance theorem, this method has higher precision, and in contrast to the method which completely uses the Kelvin source Green function, this method has better computational efficiency.[Conclusions] In general, the algorithm in this paper provides a compromise between precision and efficiency in wave-making resistance calculation.

Standard test method for determination of resistance to stable crack extension under low-constraint conditions

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 This standard covers the determination of the resistance to stable crack extension in metallic materials in terms of the critical crack-tip-opening angle (CTOAc), ψc and/or the crack-opening displacement (COD), δ5 resistance curve (1). This method applies specifically to fatigue pre-cracked specimens that exhibit low constraint (crack-length-to-thickness and un-cracked ligament-to-thickness ratios greater than or equal to 4) and that are tested under slowly increasing remote applied displacement. The recommended specimens are the compact-tension, C(T), and middle-crack-tension, M(T), specimens. The fracture resistance determined in accordance with this standard is measured as ψc (critical CTOA value) and/or δ5 (critical COD resistance curve) as a function of crack extension. Both fracture resistance parameters are characterized using either a single-specimen or multiple-specimen procedures. These fracture quantities are determined under the opening mode (Mode I) of loading. Influences of environment a...

Method of making sulfur-resistant composite metal membranes

Science.gov (United States)

Way, J Douglas [Boulder, CO; Lusk, Mark [Golden, CO; Thoen, Paul [Littleton, CO

2012-01-24

The invention provides thin, hydrogen-permeable, sulfur-resistant membranes formed from palladium or palladium-alloy coatings on porous, ceramic or metal supports. Also disclosed are methods of making these membranes via sequential electroless plating techniques, wherein the method of making the membrane includes decomposing any organic ligands present on the substrate, reducing the palladium crystallites on the substrate to reduced palladium crystallites, depositing a film of palladium metal on the substrate and then depositing a second, gold film on the palladium film. These two metal films are then annealed at a temperature between about 200.degree. C. and about 1200.degree. C. to form a sulfur-resistant, composite PdAu alloy membrane.

Resistivity Correction Factor for the Four-Probe Method: Experiment II

Science.gov (United States)

Yamashita, Masato; Yamaguchi, Shoji; Nishii, Toshifumi; Kurihara, Hiroshi; Enjoji, Hideo

1989-05-01

Experimental verification of the theoretically derived resistivity correction factor F is presented. Factor F can be applied to a system consisting of a disk sample and a four-probe array. Measurements are made on isotropic graphite disks and crystalline ITO films. Factor F can correct the apparent variations of the data and lead to reasonable resistivities and sheet resistances. Here factor F is compared to other correction factors; i.e. FASTM and FJIS.

Plasma resistivity measurements in the Wisconsin levitated octupole

International Nuclear Information System (INIS)

Brouchous, D.A.

1980-11-01

Resistivity measurements parallel to the magnetic field were made on gun injected plasmas ranging in density from 10 9 cm -3 to 10 1 parallelcm -3 in the Wisconsin levitated octupole with toroidal and poloidal magnetic fields. The 10 9 cm -3 plasma was collisionless with lambda/sub mfp/ > 100 mirror lengths, had T/sub e/ = 10 eV, T/sub i/ = 30 eV and was found to have anomalous resistivity scaling like eta = √T/sub e//n/sub e/ when E/sub parallel/ > E/su c/ is the Dreicer critical field. The 10 12 cm -3 plasma was collisional with lambda/sub mfp/ < mirror length, had T/sub e/ = T/sub i/ approx. = .2 eV and was found to have Spitzer resistivity when E/sub parallel/ < E/sub c/

Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe

Directory of Open Access Journals (Sweden)

Harald van Lintel

2010-01-01

Full Text Available We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility contributed to stable resistivity profiling. The resistivity was directly calculated based on the resistive part of the impedance measured with the Peak Resistance Frequency (PRF methodology. The resistivity-depth profiles for both rat and chick embryo models are in accordance with previous mammalian and avian studies in literature. We demonstrate that the measured resistivity at each depth has its own PRF signature. Resistivity profiles obtained with our setup provide the basis for the construction of an electric model of the retina. This model can be used to predict variations in parameters related to retinal stimulation and especially in the design and optimisation of efficient retinal implants.

Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor

International Nuclear Information System (INIS)

Ravelo Arias, S. I.; Ramírez Muñoz, D.; Cardoso, S.; Ferreira, R.; Freitas, P.

2015-01-01

The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially when the bridge is micro-fabricated and there is no physical way to separate one resistive element from the others

Note: A non-invasive electronic measurement technique to measure the embedded four resistive elements in a Wheatstone bridge sensor

Energy Technology Data Exchange (ETDEWEB)

Ravelo Arias, S. I.; Ramírez Muñoz, D. [Department of Electronic Engineering, University of Valencia, Avda. de la Universitat, s/n, 46100-Burjassot (Spain); Cardoso, S. [INESC Microsystems and Nanotechnologies (INESC-MN) and Institute for Nanosciences and Nanotechnologies, R. Alves Redol 9, Lisbon 1000-029 (Portugal); Ferreira, R. [INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, Braga 4715-31 (Portugal); Freitas, P. [INESC Microsystems and Nanotechnologies (INESC-MN) and Institute for Nanosciences and Nanotechnologies, R. Alves Redol 9, Lisbon 1000-029 (Portugal); INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, Braga 4715-31 (Portugal)

2015-06-15

The work shows a measurement technique to obtain the correct value of the four elements in a resistive Wheatstone bridge without the need to separate the physical connections existing between them. Two electronic solutions are presented, based on a source-and-measure unit and using discrete electronic components. The proposed technique brings the possibility to know the mismatching or the tolerance between the bridge resistive elements and then to pass or reject it in terms of its related common-mode rejection. Experimental results were taken in various Wheatstone resistive bridges (discrete and magnetoresistive integrated bridges) validating the proposed measurement technique specially when the bridge is micro-fabricated and there is no physical way to separate one resistive element from the others.

Effects of gamma oryzanol supplementation on anthropometric measurements & muscular strength in healthy males following chronic resistance training

Directory of Open Access Journals (Sweden)

Saghar Eslami

2014-01-01

Full Text Available Background & objectives: Enhanced muscle strength is seen when resistance exercise is combined with the consumption of nutritional supplements. Although there is a limited number of studies available about the efficacy of gamma oryzanol supplementation with resistance exercise in humans, but its usage as a nutritional supplement for strength is common in athletes. The aim of this study was to determine the effects of gamma oryzanol supplementation during 9-week resistance training on muscular strength and anthropometric measurements of young healthy males. Methods: In this double-blind clinical trial, changes of anthropometric measurements and muscular strength were studied after chronic resistance exercise and gamma oryzanol supplementation in 30 healthy volunteers (16 in supplement and 14 in placebo. Each day, gamma oryzanol supplement (600 mg and placebo (the same amount of lactose were consumed after training. The participants exercised with 80 per cent 1-Repetition Maximum (1-RM, for one hour and four days/week. Anthropometric measurements and subjects′ 1-RM for muscular strength were determined at the commencement and end of the 9-week study. Results: There was no significant difference between the baseline characteristics and target variables at baseline between the two groups. After gamma oryzanol supplementation, there was no significant difference in the means of anthropometric and skin fold measurements between the supplement and placebo groups. However, there were significant differences between the supplement and placebo groups for 1-RM of bench press and leg curl, which showed that gamma oryzanol improved muscle strength following resistance training. Interpretation & conclusions: Our findings indicated that 600 mg/day gamma oryzanol supplementation during the 9-week resistance training did not change anthropometric and body measurements, but it increased muscular strength in young healthy males. Further, studies need to be done

Standard method for detecting Bombyx mori nucleopolyhedrovirus disease-resistant silkworm varieties

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Yang Qiong

Full Text Available ABSTRACT Bombyx mori nucleopolyhedrovirus (BmNPV disease is one of the most serious silkworm diseases, and it has caused great economic losses to the sericulture industry. So far, the disease has not been controlled effectively by therapeutic agents. Breeding resistant silkworm varieties breeding may be an effective way to improve resistance to BmNPV and reduce economic losses. A precise resistance-detection method will help to accelerate the breeding process. For this purpose, here we described the individual inoculation method (IIM. Details of the IIM include pathogen BmNPV preparation, mulberry leaf size, pathogen volume, rearing conditions, course of infection, and breeding conditions. Finally, a resistance comparison experiment was performed using the IIM and the traditional group inoculation method (GIM. The incidence of BmNPV infection and the within-group variance results showed that the IIM was more precise and reliable than the GIM.

Modeling and Inversion Methods for the Interpretation of Resistivity Logging Tool Response

NARCIS (Netherlands)

Anderson, B.I.

2001-01-01

The electrical resistivity measured by well logging tools is one of the most important rock parameters for indicating the amount of hydrocarbons present in a reservoir. The main interpretation challenge is to invert the measured data, solving for the true resistivity values in each zone of a

New high resolution Random Telegraph Noise (RTN) characterization method for resistive RAM

Science.gov (United States)

Maestro, M.; Diaz, J.; Crespo-Yepes, A.; Gonzalez, M. B.; Martin-Martinez, J.; Rodriguez, R.; Nafria, M.; Campabadal, F.; Aymerich, X.

2016-01-01

Random Telegraph Noise (RTN) is one of the main reliability problems of resistive switching-based memories. To understand the physics behind RTN, a complete and accurate RTN characterization is required. The standard equipment used to analyse RTN has a typical time resolution of ∼2 ms which prevents evaluating fast phenomena. In this work, a new RTN measurement procedure, which increases the measurement time resolution to 2 μs, is proposed. The experimental set-up, together with the recently proposed Weighted Time Lag (W-LT) method for the analysis of RTN signals, allows obtaining a more detailed and precise information about the RTN phenomenon.

Embedded Artificial Neuval Network-Based Real-Time Half-Wave Dynamic Resistance Estimation during the A.C. Resistance Spot Welding Process

Directory of Open Access Journals (Sweden)

Liang Gong

2013-01-01

Full Text Available Online monitoring of the instantaneous resistance variation during the A.C. resistance spot welding is of paramount importance for the weld quality control. On the basis of the welding transformer circuit model, a new method is proposed to measure the transformer primary-side signal for estimating the secondary-side resistance in each 1/4 cycle. The tailored computing system ensures that the measuring method possesses a real-time computational capacity with satisfying accuracy. Since the dynamic resistance cannot be represented via an explicit function with respect to measurable parameters from the primary side of the welding transformer, an offline trained embedded artificial neural network (ANN successfully realizes the real-time implicit function calculation or estimation. A DSP-based resistance spot welding monitoring system is developed to perform ANN computation. Experimental results indicate that the proposed method is applicable for measuring the dynamic resistance in single-phase, half-wave controlled rectifier circuits.

Computational methods for structural load and resistance modeling

Science.gov (United States)

Thacker, B. H.; Millwater, H. R.; Harren, S. V.

1991-01-01

An automated capability for computing structural reliability considering uncertainties in both load and resistance variables is presented. The computations are carried out using an automated Advanced Mean Value iteration algorithm (AMV +) with performance functions involving load and resistance variables obtained by both explicit and implicit methods. A complete description of the procedures used is given as well as several illustrative examples, verified by Monte Carlo Analysis. In particular, the computational methods described in the paper are shown to be quite accurate and efficient for a material nonlinear structure considering material damage as a function of several primitive random variables. The results show clearly the effectiveness of the algorithms for computing the reliability of large-scale structural systems with a maximum number of resolutions.

Method of high precision interval measurement in pulse laser ranging system

Science.gov (United States)

Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

2013-09-01

Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

Resistivity behavior of optimized PbTiO3 thin films prepared by spin coating method

Science.gov (United States)

Nurbaya, Z.; Wahid, M. H.; Rozana, M. D.; Alrokayan, S. A. H.; Khan, H. A.; Rusop, M.

2018-05-01

Th is study presents the resistivity behavior of PbTiO3 thin films which were prepared towards metal-insulator-metal capacitor device fabrication. The PbTiO3 thin films were prepared through sol-gel spin coating method that involved various deposition parameters that is (1) different molar concentration of PbTiO3 solutions, (2) various additional PbAc-content in PbTiO3 solutions, and (3) various annealing temperature on PbTiO3 thin films. Hence, an electrical measurement of current versus voltage was done to determine the resistivity behavior of PbTiO3 thin films.

Central Hemodynamics Measured During 5 Repetition Maximum Free Weight Resistance Exercise.

Science.gov (United States)

Howard, Jonathan S; McLester, Cherilyn N; Evans, Thomas W; McLester, John R; Calloway, Jimmy P

2018-01-01

The PhysioFlow™ is a piece of equipment that uses bioimpedance cardiography to measure central hemodynamics. The purpose of this research was to explore the novel approach of monitoring central hemodynamics during free weight resistance exercise using bioimpedance cardiography throughout a 5 repetition maximum (5RM). Thirty participants ranging from beginner to advanced lifters (16 males and 14 females) completed a 5RM for back squat, seated push press, and bicep curl while connected to the PhysioFlow™ to assess the response of heart rate (HR), stroke volume (SV), cardiac output (Q), and ejection fraction (EF). Participants were cued for form and to breathe normally throughout the lifts. The PhysioFlow™ detected an increase in HR and Q for all lifts between rest and each repetition ( p 0.05) and no changes in EF or SV were detected when all repetitions were compared to each other for all lifts ( p > 0.05). In conclusion, the PhysioFlow™ was able to detect changes in HR and Q during dynamic free weight resistance exercise. This novel approach may provide a mechanism for monitoring central hemodynamics during free weight resistance training. However, more research needs to be conducted as the exercise protocol for this investigation did not allow for a comparison to a reference method.

A MODIFIED VAN DER PAUW SETUP FOR MEASURING THE RESISTIVITY AND THERMOPOWER OF THERMOELECTRIC MATERIALS OF VARYING THICKNESSES

KAUST Repository

HITCHCOCK, DALE

2013-10-01

In the investigation of thermoelectric (TE) materials as a practical, and efficient, means of power generation/ refrigeration nearly ninety percent of the possible high-efficient binary compounds have been evaluated. But only a few proved to be useful such as Bi2Te3 alloys, PbTe and SiGe to name the most important materials. Therefore, in order to expand the research of high-efficiency TE materials new compounds and methods of efficiency optimization must be explored. There currently exist a vast number of uninvestigated ternary and quaternary materials that could be potential high-efficiency thermoelectric materials. The device and methodology discussed herein deal with rapidly measuring both the electrical resistivity and the Seebeck coefficient of thermoelectric materials, at a set temperature of T ≈ 300 K. Using nontraditional resistivity measurements and rapid, room-temperature thermopower measurements, a reliable and time-efficient means of gauging the power factor (defined below) values of newly synthesized thermoelectric materials is achievable. Furthermore, the efficacy of the van der Pauw technique for measuring the resistivity of thermoelectric materials has been verified. © World Scientific Publishing Company.

A MODIFIED VAN DER PAUW SETUP FOR MEASURING THE RESISTIVITY AND THERMOPOWER OF THERMOELECTRIC MATERIALS OF VARYING THICKNESSES

KAUST Repository

HITCHCOCK, DALE; WALDROP, SPENCER; WILLIAMS, JARED; TRITT, TERRY M.

2013-01-01

In the investigation of thermoelectric (TE) materials as a practical, and efficient, means of power generation/ refrigeration nearly ninety percent of the possible high-efficient binary compounds have been evaluated. But only a few proved to be useful such as Bi2Te3 alloys, PbTe and SiGe to name the most important materials. Therefore, in order to expand the research of high-efficiency TE materials new compounds and methods of efficiency optimization must be explored. There currently exist a vast number of uninvestigated ternary and quaternary materials that could be potential high-efficiency thermoelectric materials. The device and methodology discussed herein deal with rapidly measuring both the electrical resistivity and the Seebeck coefficient of thermoelectric materials, at a set temperature of T ≈ 300 K. Using nontraditional resistivity measurements and rapid, room-temperature thermopower measurements, a reliable and time-efficient means of gauging the power factor (defined below) values of newly synthesized thermoelectric materials is achievable. Furthermore, the efficacy of the van der Pauw technique for measuring the resistivity of thermoelectric materials has been verified. © World Scientific Publishing Company.

A Simple and Sensitive Plant-Based Western Corn Rootworm Bioassay Method for Resistance Determination and Event Selection.

Science.gov (United States)

Wen, Zhimou; Chen, Jeng Shong

2018-05-26

We report here a simple and sensitive plant-based western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), bioassay method that allows for examination of multiple parameters for both plants and insects in a single experimental setup within a short duration. For plants, injury to roots can be visually examined, fresh root weight can be measured, and expression of trait protein in plant roots can be analyzed. For insects, in addition to survival, larval growth and development can be evaluated in several aspects including body weight gain, body length, and head capsule width. We demonstrated using the method that eCry3.1Ab-expressing 5307 corn was very effective against western corn rootworm by eliciting high mortality and significantly inhibiting larval growth and development. We also validated that the method allowed determination of resistance in an eCry3.1Ab-resistant western corn rootworm strain. While data presented in this paper demonstrate the usefulness of the method for selection of events of protein traits and for determination of resistance in laboratory populations, we envision that the method can be applied in much broader applications.

Comparative Analysis of Three Methods for Determination of Imipenem Resistance in Pseudomonas aeruginosa

Directory of Open Access Journals (Sweden)

Tanaz Zabihi

2016-02-01

Full Text Available "> Background: These days, the antibiotic resistance of Pseudomonas aeruginosa isolates toimipenem has significantly increased. Therefore the study of resistance to imipenem in thisorganism to imipenem in determining the appropriate treatment is crucial and necessary. The goalof this study is to compare three phenotypic methods of E-test, disk diffusion and micro brothdilution in the study of resistance to imipenem in clinical isolates of P. aeruginosa.Methods: Within a 6-month interval, 120 clinical specimens were collected and evaluated. Allisolates were identified as P. aeruginosa by standard biochemical tests and amplification of 16SrRNA gene. Three phenotypic methods of E-test, disk diffusion, and micro broth dilution wereused to determine imipenem resistance in P. aeruginosa isolates.Results: Of the 96 P. aeruginosa isolates studied for their resistance to imipenem by the use ofE-test, disk diffusion and micro broth dilution methods, 38.5% of the strains in micro broth dilutionmethod and 33.3% in the two methods of E-test and disk diffusion were resistant to imipenem. Therate of sensitivity and specificity of disk diffusion and E-test methods were 100%, 90.1%, and theywere 100% and 83.1% for micro broth dilution, respectively.Conclusions: With regard to the results obtained from the comparison of the three methods100% agreement were observed among the antimicrobial susceptibility results obtained by the Etest and disk diffusion methods (P ≥ 0.05. Therefore, the use of disk diffusion method can bean appropriate replacement for E-test method with regard to its being easy and cost-effective.

High resolution resistivity measurements at the Down Ampney research site

International Nuclear Information System (INIS)

Hallam, J.R.; Jackson, P.D.; Rainsbury, M.; Raines, M.

1991-01-01

A new high resolution resistivity surveying method is described for fault detection and characterisation. The resolution is shown to be significantly higher than conventional apparent resistivity profiling when applied to geological discontinuities such as faults. Nominal fault locations have been determined to an accuracy of 0.5 m, as proven by drilling. Two dimensional profiling and image enhancement of the resulting 2-D data set indicated the possibility of subsidiary fractures and/or lateral changes within the clay to clay' fault zone. The increased resolution allows greater confidence to be placed on both the fault detection and lateral perturbations derived from processed resistance and resistivity images. (Author)

Study of complex resistivity measurement using current and potential waveform data; Denryu to den`i hakei data wo riyoshita fukusohi teiko sokutei no kento

Energy Technology Data Exchange (ETDEWEB)

Shima, H; Sakurai, K; Yamashita, Y [OYO Corp., Tokyo (Japan)

1997-10-22

This paper proposes a measurement method for complex resistivity using both current and potential waveforms. This method was applied to actual data. Especially, chargeability was discussed among complex resistivities. A method was proposed for determining the complex resistivity. At first, digital measurements of both current and potential waveforms were conducted. For the potential waveform, zero-order self-potential was canceled. Then, the FFT technique was applied to both current and potential waveforms, to determine both current and potential in the frequency domain. Hereafter, complex resistivity was determined through simple division. Since the inductive coupling was observed at higher frequencies, it was difficult to apply Cole-Cole model, simply. However, the inductive coupling could be removed using proper sampling frequency. Thus, a proper Cole-Cole dispersion curve could be obtained. Using this Cole-Cole dispersion curve, new chargeability could be defined. A linear relation between this chargeability and the ordinary time domain chargeability was made clear. 4 refs., 10 figs.

HIV resistance testing and detected drug resistance in Europe

DEFF Research Database (Denmark)

Schultze, Anna; Phillips, Andrew N; Paredes, Roger

2015-01-01

to Southern Europe. CONCLUSIONS: Despite a concurrent decline in virological failure and testing, drug resistance was commonly detected. This suggests a selective approach to resistance testing. The regional differences identified indicate that policy aiming to minimize the emergence of resistance......OBJECTIVES: To describe regional differences and trends in resistance testing among individuals experiencing virological failure and the prevalence of detected resistance among those individuals who had a genotypic resistance test done following virological failure. DESIGN: Multinational cohort...... study. METHODS: Individuals in EuroSIDA with virological failure (>1 RNA measurement >500 on ART after >6 months on ART) after 1997 were included. Adjusted odds ratios (aORs) for resistance testing following virological failure and aORs for the detection of resistance among those who had a test were...

Application of Hot-wire Method for Measuring Thermal Conductivity of Fine Ceramics

Directory of Open Access Journals (Sweden)

Shangxi WANG

2016-11-01

Full Text Available Ceramic substrate is preferred in high density packaging due to its high electrical resistivity and moderate expansion coefficient. The thermal conductivity is a key parameter for packaging substrates. There are two common methods to measure the thermal conductivity, which are the hot-wire method and the laser-flash method. Usually, the thermal conductivities of porcelain is low and meet the measurement range of hot-wire method, and the measured value by hot-wire method has little difference with that by laser-flash method. In recent years, with the requirement of high-powered LED lighting, some kinds of ceramic substrates with good thermal conductivity have been developed and their thermal conductivity always measured by the means of laser flash method, which needs expensive instrument. In this paper, in order to detect the thermal conductivity of fine ceramic with convenience and low cost, the feasibility of replacing the laser flash method with hot wire method to measure thermal conductivity of ceramic composites was studied. The experiment results showed that the thermal conductivity value of fine ceramics measured by the hot-wire method is severely lower than that by the laser-flash method. However, there is a positive relationship between them. It is possible to measure the thermal conductivity of fine ceramic workpiece instantly by hot-wire method via a correction formula.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12543

Benchmarking of methods for identification of antimicrobial resistance genes in bacterial whole genome data

DEFF Research Database (Denmark)

Clausen, Philip T. L. C.; Zankari, Ea; Aarestrup, Frank Møller

2016-01-01

to two different methods in current use for identification of antibiotic resistance genes in bacterial WGS data. A novel method, KmerResistance, which examines the co-occurrence of k-mers between the WGS data and a database of resistance genes, was developed. The performance of this method was compared...... with two previously described methods; ResFinder and SRST2, which use an assembly/BLAST method and BWA, respectively, using two datasets with a total of 339 isolates, covering five species, originating from the Oxford University Hospitals NHS Trust and Danish pig farms. The predicted resistance...... was compared with the observed phenotypes for all isolates. To challenge further the sensitivity of the in silico methods, the datasets were also down-sampled to 1% of the reads and reanalysed. The best results were obtained by identification of resistance genes by mapping directly against the raw reads...

Archaeological prospecting using electrical resistivity method. Case history of Kaibukiyama ancient tomb; Denki tansaho ni yoru iseki tansa. Kaibukiyama kofun no chosarei

Energy Technology Data Exchange (ETDEWEB)

Mizunaga, H; Ushijima, K; Kishikawa, H [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1997-05-27

To grasp the three-dimensional structure of ancient tomb during the archaeological prospecting of Kaibukiyama ancient tomb, various electrical resistivity methods were tried. For the survey, firstly, in order to clarify the electrical resistivity structure of rear circular part of ancient tomb, roughly, mapping was conducted by means of two-electrode method using a multi-channel measuring system. Then, the vertical prospecting was conducted densely with a mesh form having VES intervals of 2 m as a detailed survey by means of Schlumberger method. For the three-dimensional inverse analysis of apparent electrical resistivity data by the two-electrode method, a program with high calculation speed was developed by using algorithm where Jacobian with a homogeneous model is adopted for the Jacobian calculation. As a result of the analysis, an outline of underground 3-D resistivity structure was determined. The resistivity anomaly with high values obtained from the results of 2-D inverse analysis of VES curve by means of Schlumberger method agreed well with the central part of the ancient tomb, which was confirmed during the archaeological survey. 4 refs., 8 figs.

Electrical resistivity borehole measurements: application to an urban tunnel site

Science.gov (United States)

Denis, A.; Marache, A.; Obellianne, T.; Breysse, D.

2002-06-01

This paper shows how it is possible to use wells drilled during geotechnical pre-investigation of a tunneling site to obtain a 2-D image of the resistivity close to a tunnel boring machine. An experimental apparatus is presented which makes it possible to perform single and borehole-to-borehole electrical measurements independent of the geological and hydrogeological context, which can be activated at any moment during the building of the tunnel. This apparatus is first demonstrated through its use on a test site. Numerical simulations and data inversion are used to analyse the experimental results. Finally, electrical resistivity tomography and single-borehole measurements on a tunneling site are presented. Experimental results show the viability of the apparatus and the efficiency of the inverse algorithm, and also highlight the limitations of the electrical resistivity tomography as a tool for geotechnical investigation in urban areas.

The `L' Array, a method to model 3D Electrical Resistivity Tomography (ERT) data

Science.gov (United States)

Chavez Segura, R. E.; Chavez-Hernandez, G.; Delgado, C.; Tejero-Andrade, A.

2010-12-01

The electrical resistivity tomography (ERT) is a method designed to calculate the distribution of apparent electrical resistivities in the subsoil by means of a great number of observations with the aim of determining an electrical image displaying the distribution of true resistivities in the subsoil. Such process can be carried out to define 2D or 3D models of the subsurface. For a 3D ERT, usually, the electrodes are placed in a squared grid keeping the distance between adjacent electrodes constant in the x and y directions. Another design employed, consists of a series of parallel lines whose space inter-lines must be smaller or equal to four times the electrode separation. The most common electrode arrays frequently employed for this type of studies are the pole-pole, pole-dipole and dipole-dipole. Unfortunately, ERT surface sampling schemes are limited by physical conditions or obstacles, like buildings, highly populated urban zones, and geologic/topographic features, where the lines of electrodes cannot be set. However, it is always necessary to characterize the subsoil beneath such anthropogenic or natural features. The ‘L’ shaped array has the main purpose to overcome such difficulties by surrounding the study area with a square of electrode lines. The measurements are obtained by switching automatically current and potential electrodes from one line to the other. Each observation adds a level of information, from one profile to the other. Once the total levels of data are completed, the opposite ‘L’ array can be measured following the same process. The complete square is computed after the parallel profiles are observed as well. At the end, the computed resistivities are combined to form a 3D matrix of observations. Such set of data can be inverted to obtain the true resistivity distribution at depth in the form of a working cube, which can be interpreted. The method was tested with theoretical models, which included a set of two resistive cubes

A METHOD FOR CREATING STRUCTURES OR DEVICES USING AN ORGANIC ICE RESIST

DEFF Research Database (Denmark)

2017-01-01

The invention relates to a method for creating an organic resist on a surface of a cooled substrate, the method comprising the steps of condensing a vapour into a solid film on the surface of the cooled substrate; patterning at least part of the solid film by exposing selected portions of said...... solid film to at least one electron beam thereby creating the organic resist on 5 the surface of the cooled substrate in accordance with a predetermined pattern; wherein the created organic resist remains essentially intact at ambient conditions; and using the created organic resist as a mask...... for creating semiconductor structures and/or semiconductor devices....

A method to improve tree water use estimates by distinguishing sapwood from heartwood using Electrical Resistivity Tomography

Science.gov (United States)

Guyot, A.; Ostergaard, K.; Lenkopane, M.; Fan, J.; Lockington, D. A.

2011-12-01

Estimating whole-plant water use in trees requires reliable and accurate methods. Measuring sap velocity and extrapolating to tree water use is seen as the most commonly used. However, deducing the tree water use from sap velocity requires an estimate of the sapwood area. This estimate is the highest cause of uncertainty, and can reach more than 50 % of the uncertainty in the estimate of water use per day. Here, we investigate the possibility of using Electrical Resistivity Tomography to evaluate the sapwood area distribution in a plantation of Pinus elliottii. Electric resistivity tomographs of Pinus elliottii show a very typical pattern of electrical resistivity, which is highly correlated to sapwood and heartwood distribution. To identify the key factors controlling the variation of electrical resistivity, cross sections at breast height for ten trees have been monitored with electrical resistivity tomography. Trees have been cut down after the experiment to identify the heartwood/sapwood boundaries and to extract wood and sap samples. pH, electrolyte concentration and wood moisture content have then been analysed for these samples. Results show that the heartwood/sapwood patterns are highly correlated with electrical resistivity, and that the wood moisture content is the most influencing factor controlling the variability of the patterns. These results show that electric resistivity tomography could be used as a powerful tool to identify the sapwood area, and thus be used in combination with sapflow sensors to map tree water use at stand scale. However, if Pinus elliottii shows typical patterns, further work is needed to identify to see if there are species - specific characterictics as shown in previous works (, electrolyte gradients from the bark to the heartwood). Also, patterns of high resistivity in between needles positions, which are not correlated with either wood moisture content or sapwood, appear to be artifacts. Thus, inversion methods have also to

Electrical resistivity measurements to predict abrasion resistance of ...

Indian Academy of Sciences (India)

WINTEC

increasing expansion of highway and other construction works and decreasing natural aggregate resources in the world, the demand for crushed stone aggregates has in- creased from day-to-day. One of the important properties of rock aggregates is abrasion resistance. The abrasion resistance of aggregates is generally ...

Measurement of metal/carbon nanotube contact resistance by adjusting contact length using laser ablation

Energy Technology Data Exchange (ETDEWEB)

Lan Chun; Srisungsitthisunti, Pornsak; Amama, Placidus B; Fisher, Timothy S; Xu Xianfan; Reifenberger, Ronald G [Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 (United States)], E-mail: lan0@physics.purdue.edu

2008-03-26

A technique of measuring contact resistance between an individual nanotube and a deposited metallic film is described. Using laser ablation to sequentially shorten the contact length between a nanotube and the evaporated metallic film, the linear resistivity of the nanotube as well as the specific contact resistivity between the nanotube and metallic film can be determined. This technique can be generally used to measure the specific contact resistance that develops between a metallic film and a variety of different nanowires and nanotubes.

Development of fatigue resistance evaluation method for socket-weld-jointed pipes

International Nuclear Information System (INIS)

Noguchi, Shinji; Shibayama, Motoaki; Iwata, Masazumi; Matsuura, Masayuki

2003-01-01

Vent line, drain line and sampling line in nuclear power station have many socket welded-joints made of austenitic stainless steel. Their slenderness and stagnation yield some potential of vibration-induced cracking and stress corrosion cracking. For the joints under vibration, the authors firstly elucidated their welding-defect-related fatigue strength by using fracture mechanics. It could define the allowable sets of stress amplitude and defect size. Secondly, authors developed an ultra-sonic detecting apparatus by using a focus-type probe and its programmed crawl on socket part. The authors finally measured the stress amplitude and frequency by sticking strain gage on suspected joints, then evaluated the fatigue resistance of the joints. For more efficient procedure, the method of stress amplitude analysis through vibration measurement is being developed. (author)

Development of Convenient Screening Method for Resistant Radish to Plasmodiophora brassicae

Directory of Open Access Journals (Sweden)

Su-Jung Jo

2011-08-01

Full Text Available To establish simple and reliable screening method for resistant radish to Plasmodiophora brassicae Woron. using soil-drenching inoculation, the development of clubroot on radish seedlings inoculated with P. brassicae GN-1 isolate according to several conditions such as inoculum concentration, plant growth stage and incubation period after inoculation was studied. To select resistant radish against clubroot, 10-day-old seedlings were inoculated with P. brassicae by drenching the roots with the spore suspension of the pathogen to give 1×10(9 spores/pot. The inoculated seedlings were incubated in a growth chamber at 20℃ for 3 days then cultivated in a greenhouse (20±5℃ for 6 weeks. Under the optimum conditions, 46 commercial cultivars of radish were tested for resistance to YC-1 (infecting 15 clubroot-resistant cultivars of Chinese cabbage and GN-1 (wild type isolates of P. brassicae. Among them, thirty-five cultivars showed resistance to both isolates and one cultivar represented susceptible response to the pathogens. On the other hand, the other cultivars showed different responses against the tested P. brassicae pathogens. The results suggest that this method is an efficient system for screening radish with resistance to clubroot.

Development of a new method of measurement of the polarization resistance to estimate the level of corrosion of the reinforced concrete of cooling towers

International Nuclear Information System (INIS)

Mitzithra, M.E.; Deby, F.; Laurens, S.; Balayssac, J.P.; Salin, J.

2014-01-01

This paper summarises the results obtained from the numerical simulations of an operative measurement mode of polarization resistance adapted for evaluating the corrosion of reinforced concrete on cooling towers. A simple operative measurement mode of R p is proposed, adapted for cooling towers submitted to corrosion due to carbonation. By means of numerical experimentations, abacuses and correction laws are built involving the different influencing parameters: steel reinforcement's concrete cover, concrete resistivity and current intensity injected from the counter electrode. Finally, a first application of the proposed procedure for calculating the real value of R p in laboratory conditions is presented. (authors)

Validity of the Maudsley Staging Method in Predicting Treatment-Resistant Depression Outcome Using the Netherlands Study of Depression and Anxiety

NARCIS (Netherlands)

van Belkum, Sjoerd M; Geugies, Hanneke H; Lysen, Thom S; Cleare, Anthony J; Peeters, Frenk P M L; Penninx, Brenda W J H; Schoevers, Robert A; Ruhe, Eric G

2018-01-01

OBJECTIVE: We investigated if the degree of treatment resistance of depression, as measured by the Maudsley Staging Method (MSM), is predictive of a worse depression outcome by using a large naturalistic cohort of depressed patients. METHODS: 643 subjects from the general population, primary care,

Slope failures evaluation and landslides investigation using 2-D resistivity method

Directory of Open Access Journals (Sweden)

M.M. Nordiana

2018-06-01

Full Text Available Slope failure is a complex phenomenon that may caused to landslides. Buildings and infrastructure such as transportation facilities and pipelines located within the boundaries of a landslide can be damaged or destroyed. Slope failure classification and various factors contributing to the instability using 2-D resistivity survey conducted in Selangor, Malaysia are described. Six 2-D resistivity survey lines with 5 m minimum electrode spacing using Pole-dipole array were performed. The data were processed using Res2Dinv and surfer10 software to evaluate the subsurface characteristics. The 2-D resistivity results show that the subsurface consist of two main zones. The first zone was alluvium or highly weathered with resistivity value of 100–1000 Ω m and depth of >30 m. This zone consists of saturated area with resistivity value of 1–100 Ω m and boulders with resistivity value of 1200–7000 Ω m. The second zone with resistivity value of >7000 Ω m was interpreted as granitic bedrock. The study area was characterized by saturated zones, highly weathered zone, highly contain of sand and boulders that will trigger slope failure in the survey area. This will cause to low strength of soil, debris flow and movement of earth. On the basis of the case examples described, 2-D resistivity method is categorized into desirable and useful method in determination of slope failure and future assessments. Keywords: Slope failure, Landslides, 2-D resistivity, Saturated, Boulders

In situ resistance measurements of bronze process Nb-Sn-Cu-Ta multifilamentary composite conductors during reactive diffusion

International Nuclear Information System (INIS)

Tan, K S; Hopkins, S C; Glowacki, B A; Majoros, M; Astill, D

2004-01-01

The conditions under which the Nb 3 Sn intermetallic layer is formed by solid-state reactive diffusion processes in bronze process multifilamentary conductors greatly influence the performance of the conductors. By convention, isothermal heat treatment is used and often causes non-uniformity of A15 layers formed across the wire. Therefore, characterization and optimization of the conductor during the reactive diffusion processes is crucial in order to improve the overall conductor's performance. In this paper, a different characterization approach and perhaps an optimization technique is presented, namely in situ resistance measurement by an alternating current (AC) method. By treating the components of such multifilamentary wires as a set of parallel resistors, the resistances of the components may be combined using the usual rules for resistors in parallel. The results show that the resistivity of the entire wire changes significantly during the reactive diffusion processes. The development of the Nb 3 Sn layer in bronze process Nb-Sn-Cu-Ta multifilamentary wires at different stages of the reactive diffusion processes has been monitored using measured resistivity changes, and correlated with results from DTA, ACS, SEM and EDS

Electrical limit of silver nanowire electrodes: Direct measurement of the nanowire junction resistance

KAUST Repository

Selzer, Franz; Floresca, Carlo; Kneppe, David; Bormann, Ludwig; Sachse, Christoph; Weiß , Nelli; Eychmü ller, Alexander; Amassian, Aram; Mü ller-Meskamp, Lars; Leo, Karl

2016-01-01

We measure basic network parameters of silvernanowire (AgNW) networks commonly used as transparent conductingelectrodes in organic optoelectronic devices. By means of four point probing with nanoprobes, the wire-to-wire junction resistance and the resistance of single nanowires are measured. The resistanceRNW of a single nanowire shows a value of RNW=(4.96±0.18) Ω/μm. The junction resistanceRJ differs for annealed and non-annealed NW networks, exhibiting values of RJ=(25.2±1.9) Ω (annealed) and RJ=(529±239) Ω (non-annealed), respectively. Our simulation achieves a good agreement between the measured network parameters and the sheet resistanceRS of the entire network. Extrapolating RJ to zero, our study show that we are close to the electrical limit of the conductivity of our AgNW system: We obtain a possible RS reduction by only ≈20% (common RS≈10 Ω/sq). Therefore, we expect further performance improvements in AgNW systems mainly by increasing NW length or by utilizing novel network geometries.

Electrical limit of silver nanowire electrodes: Direct measurement of the nanowire junction resistance

KAUST Repository

Selzer, Franz

2016-04-19

We measure basic network parameters of silvernanowire (AgNW) networks commonly used as transparent conductingelectrodes in organic optoelectronic devices. By means of four point probing with nanoprobes, the wire-to-wire junction resistance and the resistance of single nanowires are measured. The resistanceRNW of a single nanowire shows a value of RNW=(4.96±0.18) Ω/μm. The junction resistanceRJ differs for annealed and non-annealed NW networks, exhibiting values of RJ=(25.2±1.9) Ω (annealed) and RJ=(529±239) Ω (non-annealed), respectively. Our simulation achieves a good agreement between the measured network parameters and the sheet resistanceRS of the entire network. Extrapolating RJ to zero, our study show that we are close to the electrical limit of the conductivity of our AgNW system: We obtain a possible RS reduction by only ≈20% (common RS≈10 Ω/sq). Therefore, we expect further performance improvements in AgNW systems mainly by increasing NW length or by utilizing novel network geometries.

Abrasion Resistance of Nano Silica Modified Roller Compacted Rubbercrete: Cantabro Loss Method and Response Surface Methodology Approach

Science.gov (United States)

Adamu, Musa; Mohammed, Bashar S.; Shafiq, Nasir

2018-04-01

Roller compacted concrete (RCC) when used for pavement is subjected to skidding/rubbing by wheels of moving vehicles, this causes pavement surface to wear out and abrade. Therefore, abrasion resistance is one of the most important properties of concern for RCC pavement. In this study, response surface methodology was used to design, evaluate and analyze the effect of partial replacement of fine aggregate with crumb rubber, and addition of nano silica on the abrasion resistance of roller compacted rubbercrete (RCR). RCR is the terminology used for RCC pavement where crumb rubber was used as partial replacement to fine aggregate. The Box-Behnken design method was used to develop the mixtures combinations using 10%, 20%, and 30% crumb rubber with 0%, 1%, and 2% nano silica. The Cantabro loss method was used to measure the abrasion resistance. The results showed that the abrasion resistance of RCR decreases with increase in crumb rubber content, and increases with increase in addition of nano silica. The analysis of variance shows that the model developed using response surface methodology (RSM) has a very good degree of correlation, and can be used to predict the abrasion resistance of RCR with a percentage error of 5.44%. The combination of 10.76% crumb rubber and 1.59% nano silica yielded the best combinations of RCR in terms of abrasion resistance of RCR.

An innovative method for ideal and resistive MHD stability analysis of tokamaks

International Nuclear Information System (INIS)

Tokuda, S.

2001-01-01

An advanced asymptotic matching method of ideal and resistive MHD stability analysis in tokamak is reported. The report explains a solution method of two-dimensional Newcomb equation, dispersion relation for an unstable ideal MHD mode in tokamak, and a new scheme for solving resistive MHD inner layer equations as an initial-value problem. (author)

An innovative method for ideal and resistive MHD stability analysis of tokamaks

International Nuclear Information System (INIS)

Tokuda, S.

2001-01-01

An advanced asymptotic matching method of ideal and resistive MHD stability analysis in tokamaks is reported. A solution method for the two dimensional Newcomb equation, a dispersion relation for an unstable ideal MHD mode in tokamaks and a new scheme for solving resistive MHD inner layer equations as an initial value problem are reported. (author)

Prediction of liquid metal alloy radiant properties from measurements of the Hall coefficient and the direct current resistivity

International Nuclear Information System (INIS)

Havstad, M.A.; Qiu, T.

1995-04-01

The thermal radiative properties of high temperature solid and liquid metal alloys are particularly useful to research and development efforts in laser cladding and machining, electron beam welding and laser isotope separation. However the cost, complexity, and difficulty of measuring these properties have forced the use of crude estimates from the Hagen-Rubens relation, the Drude relations, or extrapolation from low temperature or otherwise flawed data (e.g., oxidized). The authors have found in this work that published values for the Hall coefficient and the electrical resistivity of liquid metal alloys can provide useful estimates of the reflectance and emittance of some groups of binary liquid metal and high temperature solid alloys. The estimation method computes the Drude free electron parameters, and thence the optical constants and the radiant properties from the dependence of the Hall coefficient and direct current resistivity on alloy composition (the Hall coefficient gives the free electron density and the resistivity gives the average time between collisions). They find that predictions of the radiant properties of molten cerium-copper alloy, which use the measured variations in the Hall coefficient and resistivity (both highly nonlinear) as a function of alloy fraction (rather than linear combinations of the values of the pure elements) yield a good comparison to published measurements of the variation of the normal spectral emittance (a different but also nonlinear function) of cerium-copper alloy at the single wavelength available for comparison, 0.645 μm. The success of the approach in the visible range is particularly notable because one expects a Drude based approach to improve with increasing wavelength from the visible into the infrared. Details of the estimation method, the comparison between the calculation and the measured emittance, and a discussion of what groups of elements may also provide agreement is given

hp-HGS strategy for inverse 3D DC resistivity logging measurement simulations

KAUST Repository

Gajda-Zaǵorska, Ewa; Paszý nski, Maciej; Schaefer, Robert; Pardo, David; Calo, Victor M.

2012-01-01

In this paper we present a twin adaptive strategy hp-HGS for solving inverse problems related to 3D DC borehole resistivity measurement simulations. The term “simulation of measurements” is widely used by the geophysical community. A quantity of interest, voltage, is measured at a receiver electrode located in the logging instrument. We use the self-adaptive goal-oriented hp-Finite Element Method (hp-FEM) computer simulations of the process of measurements in deviated wells (when the angle between the borehole and formation layers are < 90 deg). We also employ the hierarchical genetic search (HGS) algorithm to solve the inverse problem. Each individual in the population represents a single configuration of the formation layers. The evaluation of the individual is performed by solving the direct problem by means of the hp-FEM algorithm and by comparison with measured logging curve. We conclude the paper with some discussion on the parallelization of the algorithm.

hp-HGS strategy for inverse 3D DC resistivity logging measurement simulations

KAUST Repository

Gajda-Zaǵorska, Ewa

2012-06-02

In this paper we present a twin adaptive strategy hp-HGS for solving inverse problems related to 3D DC borehole resistivity measurement simulations. The term “simulation of measurements” is widely used by the geophysical community. A quantity of interest, voltage, is measured at a receiver electrode located in the logging instrument. We use the self-adaptive goal-oriented hp-Finite Element Method (hp-FEM) computer simulations of the process of measurements in deviated wells (when the angle between the borehole and formation layers are < 90 deg). We also employ the hierarchical genetic search (HGS) algorithm to solve the inverse problem. Each individual in the population represents a single configuration of the formation layers. The evaluation of the individual is performed by solving the direct problem by means of the hp-FEM algorithm and by comparison with measured logging curve. We conclude the paper with some discussion on the parallelization of the algorithm.

Thermal strain measurement of EAST W/Cu divertor structure using electric resistance strain gauges

Energy Technology Data Exchange (ETDEWEB)

Wang, Xingli [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Wang, Wanjing, E-mail: wjwang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Wang, Jichao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Wei, Ran; Sun, Zhaoxuan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Li, Qiang; Xie, Chunyi [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Chen, Hong-En; Wang, Kaiqiang; Wu, Lei; Chen, Zhenmao [State Key Lab for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Science Island Branch of Graduate School, University of Science & Technology of China, Hefei, 230031 (China); Hefei Center for Physical Science and Technology, Hefei, 230022 (China); Hefei Science Center of Chinese Academy of Sciences, Hefei, 230027 (China)

2016-12-15

Highlights: • To understand the service behavior of W/Cu divertor, an electrical resistance strain gauge system had been introduced in a thermal strain measurement experiment. • The measurement system successfully finished the experiment and obtained valued thermal strain data. • Two thermomechanical analyses had also been carried out and compared with the measurement results. • Experiment results corresponded well to simulations and threw a light upon the failure of W/Cu divertor in the previous baking tests. - Abstract: W/Cu divertor has complex structure and faces extreme work environment in EAST Tokamak device. To measure its thermal strain shall be a valued way to understand its service behavior and then optimize its design and manufacturing process. This work presents a preliminary study on measuring thermal strain of EAST W/Cu divertor structure using electric resistance strain gauges. Eight gauges had been used in the experiment and the heating temperature had been set to 230 °C with respect to the work temperature. To realize the measuring experiment, an appropriate fixing method of gauges in divertor narrow spaces had been taken and tested, which could not only withstand high temperature but also had no damage to the divertor sample. The measurement results were that three gauges showed positive strain while other three showed negative strain after having been compensated, which corresponded to tensile stress and compressed stress respectively. Two thermomechanical simulations had also been carried out and used for comparing with the experiment.

Micro-four-point Probe Hall effect Measurement method

DEFF Research Database (Denmark)

Petersen, Dirch Hjorth; Hansen, Ole; Lin, Rong

2008-01-01

barriers and with a magnetic field applied normal to the plane of the sheet. Based on this potential, analytical expressions for the measured four-point resistance in presence of a magnetic field are derived for several simple sample geometries. We show how the sheet resistance and Hall effect...

Detection of gas in landfills using resistivity measurements; Detektering av gas i deponier med resistivitet

Energy Technology Data Exchange (ETDEWEB)

Rosqvist, Haakan; Leroux, Virginie; Lindsjoe, Magnus (NSR AB, Helsingborg (Sweden)); Dahlin, Torleif (Lund Univ., LTH (Sweden)); Svensson, Mats; Maansson, Carl-Henrik (Tyrens AB, Stockholm (Sweden))

2009-05-15

The main objective with the research project was to develop a methodology to improve the understanding of landfill gas migration in landfills, based on measurements with electrical resistivity. Consequently, the project aimed at an improvement of the utilisation of the energy potential in landfill gas, and to reduce the environmental impact to the atmosphere. Further more, the objective was to improve techniques for investigations of internal structures in landfills. The project also aimed at better understanding of gas migration in the waste body and the mitigation through a landfill cover. Measurements were performed at four landfills; the Biocell reactor (NSR, Helsingborg), the Filborna landfill (NSR, Helsingborg), the Hyllstofta landfill (Naarab, Klippan) and the Flishult landfill (Vetab, Vetlanda). Three dimensional (3D) measurements and analysis were performed. The measurements were repeated in time in order to study changes with time for the resistivity. Supplementary information was created by measurement of other parameters, such as, groundwater table and soil temperature. The results from the resistivity measurements agreed with previous measurements performed at landfills, and thus, the results are therefore regarded as reliable. The measurements showed large temporal and spatial variations, and all of the measurements showed the highest variability near the surface. The results show that the resistivity technique is a powerful tool for investigations of the internal of landfills. Water and gas migration are important features in landfill management and both processes can be detected by using resistivity. Degradation of organic waste results in process with high variability in time and space. Also the degradation rate varies in a landfill and high variability was registered during the resistivity measurements. The high variability in resistivity is likely to be explained by changes in gas pressure and thus indicating gas migration. Therefore, the project

Measurement of resistance switching dynamics in copper sulfide memristor structures

Science.gov (United States)

McCreery, Kaitlin; Olson, Matthew; Teitsworth, Stephen

Resistance switching materials are the subject of current research in large part for their potential to enable novel computing devices and architectures such as resistance random access memories and neuromorphic chips. A common feature of memristive structures is the hysteretic switching between high and low resistance states which is induced by the application of a sufficiently large electric field. Here, we describe a relatively simple wet chemistry process to fabricate Cu2 S / Cu memristive structures with Cu2 S film thickness ranging up to 150 micron. In this case, resistance switching is believed to be mediated by electromigration of Cu ions from the Cu substrate into the Cu2 S film. Hysteretic current-voltage curves are measured and reveal switching voltages of about 0.8 Volts with a relatively large variance and independent of film thickness. In order to gain insight into the dynamics and variability of the switching process, we have measured the time-dependent current response to voltage pulses of varying height and duration with a time resolution of 1 ns. The transient response consists of a deterministic RC component as well as stochastically varying abrupt current steps that occur within a few microseconds of the pulse application.

Measurements of the anomalous RF surface resistance of niobium using a dielectric resonator

International Nuclear Information System (INIS)

Moffat, D.; Bolore, M.; Bonin, B.; Jacques, E.; Safa, H.

1996-01-01

The surface resistance of high and low residual resistance ratio (RRR) niobium plates at 4.2 K and 1.8 K has been measured as a function of many processing and testing parameters. A dielectric resonator was used instead of a resonant cavity. This resonator offered the ability to make many, sensitive measurements with an efficient use of time and helium. It was found that the surface resistance, R s , of RRR = 190 niobium increased noticeably from the theoretical value if the cooling rate was slower than ∼ 10 K/min. (author)

Effect of electrode shape on grounding resistances - Part 1

DEFF Research Database (Denmark)

Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Dahlin, Torleif

2016-01-01

Electrode grounding resistance is a major factor affecting measurement quality in electric resistivity tomography (ERT) measurements for cryospheric applications. Still, little information is available on grounding resistances in the geophysical literature, mainly because it is difficult to measure....... The focus-one protocol is a new method for estimating single electrode grounding resistances by measuring the resistance between a single electrode in an ERT array and all the remaining electrodes connected in parallel. For large arrays, the measured resistance is dominated by the grounding resistance...... of the electrode under test, the focus electrode. We have developed an equivalent circuit model formulation for the resistance measured when applying the focus-one protocol. Our model depends on the individual grounding resistances of the electrodes of the array, the mutual resistances between electrodes...

Automation for measuring the surface resistivity of RPC by Arduino motor shield

International Nuclear Information System (INIS)

Pandey, A.; Kumar, A.; Singh, M.K.; Marimuthu, N.; Singh, V.

2016-01-01

India Based Neutrino Observatory (INO) is planning to use ∼ 30,000 Resistive Plate Chamber (RPC) detectors of size 2m x 2m. Each resistive plate chamber is made up of glass or Bakelite whose resistance is of the order 10 12 Ω/cm 2 , and two pick-up panels. Both glass electrodes of the detector have one side (outer) painted with thin and uniform coating of graphite paint. This provides the resistivity of range 100 - 300 kΩ per square. This range of resistivity provides distribution of voltage over the surface of glass electrodes. Uniform coating will provide uniform electric field inside the glass plate chamber and high resistivity value will help in confining the induced charge on the surface. It is one of the necessary criteria for good RPC detector that the coating of graphite paint should be uniform. Therefore it is required to measure the resistivity for the verification of uniformity. Last few years we have been focusing our efforts in this direction. In this connection, we made sequential improvement from the previous work. The present system is cost effective, automatically recording measurement in the computer, fast and accurate. Earlier MOTOR BEE ver. 5.0 microcontroller was used which was an imported and costly material. After massive search in the local market Arduino microcontroller was discovered, which controls the movement of all motors and it also saves the value of resistivity in the computer automatically

TECHNICAL EVALUATION OF ELECTRICAL RESISTIVITY METHODS AT THE DEPARTMENT OF ENERGY HANFORD SITE

International Nuclear Information System (INIS)

PETERSEN SW

2008-01-01

There is a continuing need for cost-effective subsurface characterization within the vadose zone and groundwater at the U.S. Department of Energy (DOE) Hanford Site, Richland, Washington. With more than 1600 liquid and solid waste sites and 200 burial sites, contaminants have migrated to and through the vadose zone. In addition, future groundwater plumes may be generated from contaminants presently in the vadose zone. Relatively low-cost geophysical techniques can provide spatially extensive data that may provide information about the presence and extent of some contaminants. Recent electrical resistivity surveys at Hanford have provided encouraging results for mapping of some contaminants, such as nitrate, in the vadose zone. Because mobile radionuclides and trace elements may have been transported with nitrate through the vadose zone, the method may be used to map some mobile contaminants of concern, such as technetium-99 (99Tc). Validation of these recent electrical resistivity survey results remains to be completed. Electrical resistivity surveys have been conducted at various waste sites in the 200 Area of the Hanford Site: BC Cribs and Trenches (BCCT), T, S, U, C, B Tank Farms and the Purex Plant. Surveys have been completed using surface and well-to-well (WTW) array configurations. The goals of the surveys, as described by Fluor Hanford and CH2MHill Hanford staff, were to test the applicability of resistivity methods in identifying the presence of and mapping approximate extent of contaminant plumes within the vadose zone. The overall goal of the project was to evaluate the utility of electrical resistivity methods for characterizing contaminants of potential concern in the vadose zone in the 200 Area of the Hanford Site. The panel was asked to perform the following activities: (1) Evaluate recently completed and ongoing electrical resistivity projects at Hanford in terms of methodology used, results obtained, and lessons learned, with specific focus on (a

Prediction of insulin resistance with anthropometric measures: lessons from a large adolescent population

Directory of Open Access Journals (Sweden)

Wedin WK

2012-07-01

Full Text Available William K Wedin,1 Lizmer Diaz-Gimenez,1 Antonio J Convit1,21Department of Psychiatry, NYU School of Medicine, New York, NY, USA; 2Nathan Kline Institute, Orangeburg, NY, USAObjective: The aim of this study was to describe the minimum number of anthropometric measures that will optimally predict insulin resistance (IR and to characterize the utility of these measures among obese and nonobese adolescents.Research design and methods: Six anthropometric measures (selected from three categories: central adiposity, weight, and body composition were measured from 1298 adolescents attending two New York City public high schools. Body composition was determined by bioelectric impedance analysis (BIA. The homeostatic model assessment of IR (HOMA-IR, based on fasting glucose and insulin concentrations, was used to estimate IR. Stepwise linear regression analyses were performed to predict HOMA-IR based on the six selected measures, while controlling for age.Results: The stepwise regression retained both waist circumference (WC and percentage of body fat (BF%. Notably, BMI was not retained. WC was a stronger predictor of HOMA-IR than BMI was. A regression model using solely WC performed best among the obese II group, while a model using solely BF% performed best among the lean group. Receiver operator characteristic curves showed the WC and BF% model to be more sensitive in detecting IR than BMI, but with less specificity.Conclusion: WC combined with BF% was the best predictor of HOMA-IR. This finding can be attributed partly to the ability of BF% to model HOMA-IR among leaner participants and to the ability of WC to model HOMA-IR among participants who are more obese. BMI was comparatively weak in predicting IR, suggesting that assessments that are more comprehensive and include body composition analysis could increase detection of IR during adolescence, especially among those who are lean, yet insulin-resistant.Keywords: BMI, bioelectrical impedance

3D electrical method and step continuous wave radar method for Nojima site. Results of measurement of resistivity at trench site; Nojima danso ni okeru sanjigenhi teikoho to step shiki renzokuha chika radar ho tansa. Trench chosa chiten deno hiteiko sokutei kekka

Energy Technology Data Exchange (ETDEWEB)

Suzuki, K; Oda, Y; Tank, K [Central Research Institute of Electric Power Industry, Tokyo (Japan); Hayashi, H [Kawasaki Geological Engineering Co. Ltd., Tokyo (Japan); Jomori, A [Japan Crust Research, Tokyo (Japan)

1996-05-01

Several surveys were carried out near the Nojima fault, including three-dimensional resistivity measurement and underground radar survey at the Ogura area, underground radar survey at the Hirabayashi area, and resistivity measurement in the vicinity of the trench at the Nashinomoto area, in order to investigate in detail the underground structures at a depth up to several tens meters from the ground surface. Resistivity was measured by an automatic analyzer capable of simultaneously measuring potential levels at 14 channels which can cover 112 measuring points at the largest. At the Ogura area, the boundary planes of the resistivity structures are continuously detected in the direction of the fault moving during the earthquake period. The underground radar measurement results suggest accumulated displacement of strata at a depth of around 25m in the Osaka Strata and flexible structures. At the Hirabayashi area, the underground radar analysis detects discrete sections in the reflection planes at the fault position, but no reflection planes of high continuity. At the Nashinomoto area, the clay stratum detected in the fault by excavating the trenches are found to be low in resistivity by the resistivity measurement. 4 refs., 11 figs., 2 tabs.

Resistance Torque Based Variable Duty-Cycle Control Method for a Stage II Compressor

Science.gov (United States)

Zhong, Meipeng; Zheng, Shuiying

2017-07-01

The resistance torque of a piston stage II compressor generates strenuous fluctuations in a rotational period, and this can lead to negative influences on the working performance of the compressor. To restrain the strenuous fluctuations in the piston stage II compressor, a variable duty-cycle control method based on the resistance torque is proposed. A dynamic model of a stage II compressor is set up, and the resistance torque and other characteristic parameters are acquired as the control targets. Then, a variable duty-cycle control method is applied to track the resistance torque, thereby improving the working performance of the compressor. Simulated results show that the compressor, driven by the proposed method, requires lower current, while the rotating speed and the output torque remain comparable to the traditional variable-frequency control methods. A variable duty-cycle control system is developed, and the experimental results prove that the proposed method can help reduce the specific power, input power, and working noise of the compressor to 0.97 kW·m-3·min-1, 0.09 kW and 3.10 dB, respectively, under the same conditions of discharge pressure of 2.00 MPa and a discharge volume of 0.095 m3/min. The proposed variable duty-cycle control method tracks the resistance torque dynamically, and improves the working performance of a Stage II Compressor. The proposed variable duty-cycle control method can be applied to other compressors, and can provide theoretical guidance for the compressor.

A review of methods to evaluate borehole thermal resistances in geothermal heat-pump systems

Energy Technology Data Exchange (ETDEWEB)

Lamarche, Louis; Kajl, Stanislaw; Beauchamp, Benoit [Ecole de Technologie Superieure, 1100 Notre-Dame Ouest, Montreal (Canada)

2010-06-15

In the design of a ground-source heat pump (GSHP) system, the heat transfer from the fluid to the ground is influenced by the thermal borehole resistance between the fluid and the borehole surface and also by the interference resistance between the two (or four) pipes inside the borehole. Several authors have proposed empirical and theoretical relations to evaluate these resistances as well as methods to evaluate them experimentally. The paper compares the different approaches and proposes good practice to evaluate the resistances. The impact of the different approaches on the design of heat exchanger is also examined. Two-dimensional and fully three-dimensional numerical simulations are used to evaluate the different methods. A new method is also proposed to evaluate the borehole resistances from in situ tests. (author)

In vitro screening methods for assessing plant disease resistance

International Nuclear Information System (INIS)

Lebeda, A.; Svabova, L.

2010-01-01

A combination of biotechnological and phytopathological techniques provides an alternative approach to classical resistance breeding methods. Such techniques have been increasingly used since the 1980s, in parallel with the progress in plant biotechnology. In the approach of resistance screening and selection in vitro, both experimental objects, i.e., the plant and the pathogen, must first be transferred to in vitro conditions, and finally, the plant material must be transferred back to in vivo conditions and adapted to the outside settings. Specific attention must be paid to the methods of pathogen preparation for use in screening and selection in vitro. The selection agents are classified according to their origin, the methods of preparation, nature and content of active substances, and effective utilisation for screening or selection in vitro. Basic principles and methodological aspects of the in vitro work (explant cultures, sources of in vitro variability, screening and selection methods, types of selection agents) as well as examples of practical applications in the breeding of different crops are critically reviewed in this chapter. (author)

Matrix diffusion studies by electrical conductivity methods. Comparison between laboratory and in-situ measurements

International Nuclear Information System (INIS)

Ohlsson, Y.; Neretnieks, I.

1998-01-01

Traditional laboratory diffusion experiments in rock material are time consuming, and quite small samples are generally used. Electrical conductivity measurements, on the other hand, provide a fast means for examining transport properties in rock and allow measurements on larger samples as well. Laboratory measurements using electrical conductivity give results that compare well to those from traditional diffusion experiments. The measurement of the electrical resistivity in the rock surrounding a borehole is a standard method for the detection of water conducting fractures. If these data could be correlated to matrix diffusion properties, in-situ diffusion data from large areas could be obtained. This would be valuable because it would make it possible to obtain data very early in future investigations of potentially suitable sites for a repository. This study compares laboratory electrical conductivity measurements with in-situ resistivity measurements from a borehole at Aespoe. The laboratory samples consist mainly of Aespoe diorite and fine-grained granite and the rock surrounding the borehole of Aespoe diorite, Smaaland granite and fine-grained granite. The comparison shows good agreement between laboratory measurements and in-situ data

Comprehensive measurement of total nondigestible carbohydrates in foods by enzymatic-gravimetric method and liquid chromatography.

Science.gov (United States)

Nishibata, Toyohide; Tashiro, Kouichi; Kanahori, Sumiko; Hashizume, Chieko; Kitagawa, Machiko; Okuma, Kazuhiro; Gordon, Dennis T

2009-09-09

Total nondigestible carbohydrate (NDC) in foods was determined by combining, not modifications, AOAC Official Methods 991.43, 2001.03, and 2002.02. Total NDC included insoluble dietary fiber (IDF) + high-molecular-weight soluble dietary fiber (HMWSDF), nondigestible oligosaccharides (NDO) not precipitated in ethanol solution, and resistant starch (RS). Eight sources of NDC (cellulose, wheat bran, gum arabic, resistant maltodextrin, polydextrose, fructooligosaccharide, galactooligosaccharides, and RS) were incorporated in different combinations into standard formula bread samples. All of the NDC sources and bread samples were analyzed for their (1) IDF + HMWSDF content with corrections for residual RS amount using AOAC Official Method 991.43, (2) NDO by liquid chromatography (LC) in AOAC Official Method 2001.03, and (3) RS by AOAC Official Method 2002.02. The correlation coefficient (R(2)) comparing calculated amounts versus measured amounts of total NDC in 11 bread samples was 0.92. Analysis of commercial food samples was also well matched with the DF + NDO value on their nutritional label. Consequently, we confirmed a single measurement of LC can determine all NDO in foods, and total NDC in foods can be determined by unifying existing AOAC Official Methods.

An Analog-Digital Mixed Measurement Method of Inductive Proximity Sensor

Directory of Open Access Journals (Sweden)

Yi-Xin Guo

2015-12-01

Full Text Available Inductive proximity sensors (IPSs are widely used in position detection given their unique advantages. To address the problem of temperature drift, this paper presents an analog-digital mixed measurement method based on the two-dimensional look-up table. The inductance and resistance components can be separated by processing the measurement data, thus reducing temperature drift and generating quantitative outputs. This study establishes and implements a two-dimensional look-up table that reduces the online computational complexity through structural modeling and by conducting an IPS operating principle analysis. This table is effectively compressed by considering the distribution characteristics of the sample data, thus simplifying the processing circuit. Moreover, power consumption is reduced. A real-time, built-in self-test (BIST function is also designed and achieved by analyzing abnormal sample data. Experiment results show that the proposed method obtains the advantages of both analog and digital measurements, which are stable, reliable, and taken in real time, without the use of floating-point arithmetic and process-control-based components. The quantitative output of displacement measurement accelerates and stabilizes the system control and detection process. The method is particularly suitable for meeting the high-performance requirements of the aviation and aerospace fields.

Irreversibility in transformation behavior of equiatomic nickel-titanium alloy by electrical resistivity measurement

International Nuclear Information System (INIS)

Matsumoto, Hitoshi

2004-01-01

Measurements of the electrical resistivity were precisely performed on shape memory Ni 50 Ti 50 alloy in order to reveal the irreversible behavior of the thermoelastic martensitic transformation with thermal cycling. The hump in the electrical resistivity during cooling is enhanced with increasing the number of complete thermal cycles to result in a peak, although no peak in the electrical resistivity is observed on the reverse transformation during heating. The electrical resistivity in the low-temperature phase, of which the temperature dependence is linear, increases with increasing the number of complete thermal cycles. The temperature coefficient of the electrical resistivity in the temperature region of the high-temperature phase increases with elevating the temperature. The transformation is strongly influenced by incomplete thermal cycles to result in a peak in the resistivity even on the reverse transformation after incomplete thermal cycling. It is thought that the anomalous behavior such as enhancement of a resistivity-peak, the increase in the electrical resistivity of the low-temperature phase, and the nonlinear relation between the resistivity and the temperature in the high-temperature phase are attributable to the appearance of an intermediate phase stabilized by transformation-induced defects, the accumulation of the transformation-induced defects, and the electron scattering due to the softening of a phonon mode in the high-temperature phase, respectively. It proved useful to make more accurate measurements of the electrical resistivity in order to investigate the intrinsic behavior of the transformation in NiTi

Using electrical resistance tomography to map subsurface temperatures

Science.gov (United States)

Ramirez, Abelardo L.; Chesnut, Dwayne A.; Daily, William D.

1994-01-01

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations.

Using electrical resistance tomography to map subsurface temperatures

Science.gov (United States)

Ramirez, A.L.; Chesnut, D.A.; Daily, W.D.

1994-09-13

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations. 1 fig.

A method for increase abrasive wear resistance parts by obtaining on methods casting on gasifying models

Science.gov (United States)

Sedukhin, V. V.; Anikeev, A. N.; Chumanov, I. V.

2017-11-01

Method optimizes hardening working layer parts’, working in high-abrasive conditions looks in this work: bland refractory particles WC and TiC in respect of 70/30 wt. % prepared by beforehand is applied on polystyrene model in casting’ mould. After metal poured in mould, withstand for crystallization, and then a study is carried out. Study macro- and microstructure received samples allows to say that thickness and structure received hardened layer depends on duration interactions blend harder carbides and liquid metal. Different character interactions various dispersed particles and matrix metal observed under the same conditions. Tests abrasive wear resistance received materials of method calculating residual masses was conducted in laboratory’ conditions. Results research wear resistance showed about that method obtaining harder coating of blend carbide tungsten and carbide titanium by means of drawing on surface foam polystyrene model before moulding, allows receive details with surface has wear resistance in 2.5 times higher, than details of analogy steel uncoated. Wherein energy costs necessary for transformation units mass’ substances in powder at obtained harder layer in 2.06 times higher, than materials uncoated.

Estimation of weld nugget temperature by thermography method in resistance projection welding process

International Nuclear Information System (INIS)

Setty, D.S.; Rameswara Roa, A.; Hemantha Rao, G.V.S.; Jaya Raj, R.N.

2008-01-01

In the Pressurized Heavy Water Reactor (PHWR) fuel manufacturing, zirconium alloy appendages like spacer and bearing pads are welded to the thin wall zirconium alloy fuel tubes by using resistance projection welding process. Out of many joining processes available, resistance-welding process is reliable, environment friendly and best suitable for mass production applications. In the fuel assembly, spacer pads are used to get the required inter-element spacing and Bearing pads are used to get the required load-bearing surface for the fuel assembly. Performance of the fuel assembly in the reactor is greatly influenced by these weld joint's quality. Phase transformation from α to β phase is not acceptable while welding these tiny appendages. At present only destructive metallography test is available for this purpose. This can also be achieved by measuring weld nugget temperature where in the phase transformation temperature for zirconium alloy material is 853 o C. The temperature distribution during resistance welding of tiny parts cannot be measured by conventional methods due to very small space and short weld times involved in the process. Shear strength, dimensional accuracy and weld microstructures are some of the key parameters used to measure the quality of appendage weld joints. Weld parameters were optimized with the help of industrial experimentation methodology. Individual projection welding by split electrode concept, and during welding on empty tube firm support is achieved on inner side of the tube by using expandable pneumatic mandrel. In the present paper, an attempt was made to measure the weld nugget temperature by thermography technique and is correlated with standard microstructures of zirconium alloy material. The temperature profiles in the welding process are presented for different welding conditions. This technique has helped in measuring the weld nugget temperature more accurately. It was observed that in the present appendage welding

Influence of the metal installations in the ground on the measurement results accuracy of the soil resistivity

International Nuclear Information System (INIS)

Acevski, Nikola; Ackovski, Risto

2002-01-01

Very often, the measurement of the specific electric resistivity of the soil performed by one of the commonly used methods introduces errors in results because of the existence of certain metal installations buried in the ground, like aqueducts, water or drainage pipes, metal strips or metal sheaths of power cables etc. An attempt has been done in the paper to give some recommendations while displacing the measuring system in order to avoid the impact of such metal installations on the measured results, and thus to avoid the eventual errors that can occur during the measurement. (Author)

Improved characterisation and modelling of measurement errors in electrical resistivity tomography (ERT) surveys

Science.gov (United States)

Tso, Chak-Hau Michael; Kuras, Oliver; Wilkinson, Paul B.; Uhlemann, Sebastian; Chambers, Jonathan E.; Meldrum, Philip I.; Graham, James; Sherlock, Emma F.; Binley, Andrew

2017-11-01

Measurement errors can play a pivotal role in geophysical inversion. Most inverse models require users to prescribe or assume a statistical model of data errors before inversion. Wrongly prescribed errors can lead to over- or under-fitting of data; however, the derivation of models of data errors is often neglected. With the heightening interest in uncertainty estimation within hydrogeophysics, better characterisation and treatment of measurement errors is needed to provide improved image appraisal. Here we focus on the role of measurement errors in electrical resistivity tomography (ERT). We have analysed two time-lapse ERT datasets: one contains 96 sets of direct and reciprocal data collected from a surface ERT line within a 24 h timeframe; the other is a two-year-long cross-borehole survey at a UK nuclear site with 246 sets of over 50,000 measurements. Our study includes the characterisation of the spatial and temporal behaviour of measurement errors using autocorrelation and correlation coefficient analysis. We find that, in addition to well-known proportionality effects, ERT measurements can also be sensitive to the combination of electrodes used, i.e. errors may not be uncorrelated as often assumed. Based on these findings, we develop a new error model that allows grouping based on electrode number in addition to fitting a linear model to transfer resistance. The new model explains the observed measurement errors better and shows superior inversion results and uncertainty estimates in synthetic examples. It is robust, because it groups errors together based on the electrodes used to make the measurements. The new model can be readily applied to the diagonal data weighting matrix widely used in common inversion methods, as well as to the data covariance matrix in a Bayesian inversion framework. We demonstrate its application using extensive ERT monitoring datasets from the two aforementioned sites.

A method enabling simultaneous pressure and temperature measurement using a single piezoresistive MEMS pressure sensor

International Nuclear Information System (INIS)

Frantlović, Miloš; Stanković, Srđan; Jokić, Ivana; Lazić, Žarko; Smiljanić, Milče; Obradov, Marko; Vukelić, Branko; Jakšić, Zoran

2016-01-01

In this paper we present a high-performance, simple and low-cost method for simultaneous measurement of pressure and temperature using a single piezoresistive MEMS pressure sensor. The proposed measurement method utilizes the parasitic temperature sensitivity of the sensing element for both pressure measurement correction and temperature measurement. A parametric mathematical model of the sensor was established and its parameters were calculated using the obtained characterization data. Based on the model, a real-time sensor correction for both pressure and temperature measurements was implemented in a target measurement system. The proposed method was verified experimentally on a group of typical industrial-grade piezoresistive sensors. The obtained results indicate that the method enables the pressure measurement performance to exceed that of typical digital industrial pressure transmitters, achieving at the same time the temperature measurement performance comparable to industrial-grade platinum resistance temperature sensors. The presented work is directly applicable in industrial instrumentation, where it can add temperature measurement capability to the existing pressure measurement instruments, requiring little or no additional hardware, and without adverse effects on pressure measurement performance. (paper)

Coal Layer Identification using Electrical Resistivity Imaging Method in Sinjai Area South Sulawesi

Science.gov (United States)

Ilham Samanlangi, Andi

2018-03-01

The purpose of this research is to image subsurface resistivity for coal identification in Panaikang Village, Sinjai, South Sulawesi.Resistivity measurements were conducted in 3 lines of length 400 meters and 300 meter using resistivity imaging, dipole-dipole configuration. Resistivity data was processed using Res2DInv software to image resistivity variation and interpret lithology. The research results shown that coal resistivity in Line is about 70-200 Ωm, Line 2 is about 70-90 Ωm, and Line 3 is about 70-200 Ωm with average thickness about 10 meters and distributed to the east of research area.

In situ measurement on TSV-Cu deformation with hotplate system based on sheet resistance

Science.gov (United States)

Sun, Yunna; Wang, Bo; Wang, Huiying; Wu, Kaifeng; Yang, Shengyong; Wang, Yan; Ding, Guifu

2017-12-01

The in situ measurement of TSVs deformation at different temperature is meaningful for learning more about the thermal deformation schemes of 3D TSVs in the microelectronic devices. An efficient and smart hotplate based on sheet resistance is designed for offering more heat, producing a uniform temperature distribution, relieving thermal stress and heat concentration issues, and reducing room space, which was optimized by the finite element method (FEM). The fabricated hotplate is efficient and smart (2.5 cm  ×  2.0 cm  ×  0.5 cm) enough to be located in the limited space during measuring. The thermal infrared imager was employed as the temperature sensor for monitoring the temperature distribution of TSVs sample. The 3D profilometry was adopted as the observer for TSVs profiles survey. The in situ 2D top surface profiles and 3D displacement profiles of TSVs sample at the different temperature were measured by 3D profilometer. The in situ average relative deformation and effective plastic deformation of the TSV sample were measured. With optical measurement method, 3D profilometry, the TSV sample can be tested repeatedly.

Clinical tooth preparations and associated measuring methods: a systematic review.

Science.gov (United States)

Tiu, Janine; Al-Amleh, Basil; Waddell, J Neil; Duncan, Warwick J

2015-03-01

The geometries of tooth preparations are important features that aid in the retention and resistance of cemented complete crowns. The clinically relevant values and the methods used to measure these are not clear. The purpose of this systematic review was to retrieve, organize, and critically appraise studies measuring clinical tooth preparation parameters, specifically the methodology used to measure the preparation geometry. A database search was performed in Scopus, PubMed, and ScienceDirect with an additional hand search on December 5, 2013. The articles were screened for inclusion and exclusion criteria and information regarding the total occlusal convergence (TOC) angle, margin design, and associated measuring methods were extracted. The values and associated measuring methods were tabulated. A total of 1006 publications were initially retrieved. After removing duplicates and filtering by using exclusion and inclusion criteria, 983 articles were excluded. Twenty-three articles reported clinical tooth preparation values. Twenty articles reported the TOC, 4 articles reported margin designs, 4 articles reported margin angles, and 3 articles reported the abutment height of preparations. A variety of methods were used to measure these parameters. TOC values seem to be the most important preparation parameter. Recommended TOC values have increased over the past 4 decades from an unachievable 2- to 5-degree taper to a more realistic 10 to 22 degrees. Recommended values are more likely to be achieved under experimental conditions if crown preparations are performed outside of the mouth. We recommend that a standardized measurement method based on the cross sections of crown preparations and standardized reporting be developed for future studies analyzing preparation geometry. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

ASSESSMENT OF CERAMIC TILE FROST RESISTANCE BY MEANS OF THE FREQUENCY INSPECTION METHOD

Directory of Open Access Journals (Sweden)

MICHAL MATYSÍK

2011-06-01

Full Text Available The paper presents some results of our experimental analysis of ceramic cladding element frost resistance, particular attention being paid to the application of the frequency inspection method. Three different sets of ceramic tiles of the Ia class to EN 14 411 B standard made by various manufacturers have been analyzed. The ceramic tiles under investigation have been subjected to freeze-thaw-cycle-based degradation in compliance with the relevant ČSN EN ISO 10545-12 standard. Furthermore, accelerated degradation procedure has been applied to selected test specimens, consisting in reducing the temperature of water soaked ceramic tiles in the course of the degradation cycles down –70°C. To verify the correctness of the frequency inspection results, additional physical properties of the ceramic tiles under test have been measured, such as, the ceramic tile strength limit, modulus of elasticity and modulus of deformability, resulting from the flexural tensile strength tests, integrity defect and surface micro-geometry tracking. It has been proved that the acoustic method of frequency inspection is a sensitive indicator of the structure condition and can be applied to the ceramic cladding element frost resistance and service life prediction assessment.

Nanolithography based contacting method for electrical measurements on single template synthesized nanowires

DEFF Research Database (Denmark)

Fusil, S.; Piraux, L.; Mátéfi-Tempfli, Stefan

2005-01-01

A reliable method enabling electrical measurements on single nanowires prepared by electrodeposition in an alumina template is described. This technique is based on electrically controlled nanoindentation of a thin insulating resist deposited on the top face of the template filled by the nanowires....... We show that this method is very flexible, allowing us to electrically address single nanowires of controlled length down to 100 nm and of desired composition. Using this approach, current densities as large as 10 A cm were successfully injected through a point contact on a single magnetic...

A nonintrusive method for measuring the operating temperature of a solenoid-operated valve

International Nuclear Information System (INIS)

Kryter, R.C.

1990-01-01

Experimental data are presented to show that the in-service operating temperature of a solenoid-operated valve (SOV) can be interred simply and nondisruptively by using the copper winding of the solenoid coil as a self-indicating, permanently available resistance thermometer. The principal merits of this approach include (a) there is no need for an add-on temperature sensor, (b) the true temperature of a critical --- and likely the hottest --- part of the SOV (namely, the electrical coil) is measured directly, (c) temperature readout can be provided at any location at which the SOV electrical lead wires are accessible (even though remote from the valve), (d) the SOV need not be disturbed (whether normally energized or deenergized) to measure its temperature in situ, and (e) the method is applicable to all types of SOVs, large and small, ac- and dc-powered. Laboratory tests comparing temperatures measured both by coil resistance and by a conventional thermometer placed in contact with the external surface of the potted solenoid coil indicate that temperature within the coil may be on the order of 40 degree C higher than that measured externally, a fact that is important to life-expectancy calculations made on the basis of Arrhenius theory. Field practicality is illustrated with temperature measurements made using this method on a SOV controlling the flow of refrigerant in a large chilled-water air-conditioning system. 5 refs., 7 figs

Faradic resistance of the electrode/electrolyte interface.

Science.gov (United States)

Mayer, S; Geddes, L A; Bourland, J D; Ogborn, L

1992-09-01

A new method is used to measure the direct-current (Faradic) resistance of a single electrode/electrolyte interface. The method employs a constant-current pulse and a potential-sensing electrode. By choosing a sufficiently long pulse duration, the voltage between the test and potential-sensing electrode exhibits a three-phase response. In the steady-state phase, the voltage measured is equal to the current flowing through the electrode Faradic resistance and the resistance of the electrolyte between the test and potential-sensing electrode. By measuring this latter resistance with a high-frequency sinusoidal alternating current, the voltage drop in the electrolyte is calculated and subtracted from the voltage measured between the test and potential-sensing electrode, thereby allowing calculation of the Faradic resistance. By plotting the reciprocal of the Faradic resistance against current density and fitting the data points to a third-order polynomial, it is possible to determine the zero-current density (Faradic) resistance. This technique was used to determine the Faradic resistance of electrodes (0.1 cm2) of stainless-steel, platinum, platinum-iridium and rhodium in 0.9 per cent NaCl at 25 degrees. The zero current Faradic resistance is lowest for platinum (30.3 k omega), slightly higher for platinum-iridium (47.6k omega), much higher for rhodium (111k omega) and highest for type 316 stainless-steel (345k omega). In all cases, the Faradic resistance decreases dramatically with increasing current density.

ArF photo resist pattern sample preparation method using FIB without protective coating

Science.gov (United States)

Okushima, Hirohisa; Onozuka, Toshihiko; Kuroda, Yasushi; Yaguchi, Toshie; Umemura, Kaoru; Tamochi, Ryuichiro; Watanabe, Kenji; Hasegawa, Norio; Kawata, Isao; Rijpers, Bart

2006-03-01

This paper presents a novel method of FIB (FIB: focused ion beam) sample preparation to accurately evaluate critical dimensions and profiles of ArF photo resist patterns without the use of a protective coating on the photo resist. In order to accomplish this, the FIB micro-sampling method that is one of effective FIB milling and fabrication method was employed. First a Si cap is picked up from a silicon wafer and fixed to ArF photo resist patterns to protect against ion beam irradiation. Then, a micro-sample, a piece of Si-capped ArF photo resist, was extracted from the bulk ArF photo resist. In this procedure, this silicon cap always protects ArF photo resist patterns against ion beam irradiation. For the next step, the micro-sample is fixed to a needle stub of the FIB-STEM (STEM: scanning transmission electron microscopy) compatible rotation holder. This sample on the needle stub was rotated 180 degrees and milled from the side of Si substrate. Lastly, the sample is milled to the thickness of 2μm. In this process, the ion beam is irradiating from the silicon substrate side to minimize the ion beam irradiation damages on the ArF photo resist patterns. EDX (EDX: Energy dispersive X-ray spectroscopy) analysis proved that no gallium ions were detected on the surface of the ArF photo resist patterns. The feasibility of high accelerating voltage observation of STEM to observe line edge roughness of a thick sample like 2μm without shrinkage has been demonstrated.

Adaptive Motor Resistance Video Game Exercise Apparatus and Method of Use Thereof

Science.gov (United States)

Reich, Alton (Inventor); Shaw, James (Inventor)

2015-01-01

The invention comprises a method and/or an apparatus using computer configured exercise equipment and an electric motor provided physical resistance in conjunction with a game system, such as a video game system, where the exercise system provides real physical resistance to a user interface. Results of user interaction with the user interface are integrated into a video game, such as running on a game console. The resistance system comprises: a subject interface, software control, a controller, an electric servo assist/resist motor, an actuator, and/or a subject sensor. The system provides actual physical interaction with a resistance device as input to the game console and game run thereon.

Quantitative Method to Measure Thermal Conductivity of One-Dimensional Nanostructures Based on Scanning Thermal Wave Microscopy

Energy Technology Data Exchange (ETDEWEB)

Park, Kyung Bae; Chung, Jae Hun; Hwang, Gwang Seok; Jung, Eui Han; Kwon, Oh Myoung [Korea University, Seoul (Korea, Republic of)

2014-12-15

We present a method to quantitatively measure the thermal conductivity of one-dimensional nanostructures by utilizing scanning thermal wave microscopy (STWM) at a nanoscale spatial resolution. In this paper, we explain the principle for measuring the thermal diffusivity of one-dimensional nanostructures using STWM and the theoretical analysis procedure for quantifying the thermal diffusivity. The SWTM measurement method obtains the thermal conductivity by measuring the thermal diffusivity, which has only a phase lag relative to the distance corresponding to the transferred thermal wave. It is not affected by the thermal contact resistances between the heat source and nanostructure and between the nanostructure and probe. Thus, the heat flux applied to the nanostructure is accurately obtained. The proposed method provides a very simple and quantitative measurement relative to conventional measurement techniques.

SEM based overlay measurement between resist and buried patterns

Science.gov (United States)

Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

2016-03-01

With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

Measurement of shear strength resistance in flexion test on PUR sandwich panels: analysis of difficulties and finite element method simulation

Directory of Open Access Journals (Sweden)

J. M. Chillón Moreno

2017-09-01

Full Text Available The use of the composite construction elements combining different materials with complementary characteristics, it has spread increasingly. The sandwich panels composed by external metallic sheets that they contributes resistance and core of rigid insulating thermal foam, that provides qualities that improve the thermal comfort inside all kinds of constructions. They are in use in closings and covers that shape the surrounding one of the buildings. Of the different quality controls to which they have to surrender. In this article one proposes an improvement to the indicated one in the procedure for the determination of the resistance to the shear strength, Managing to avoid many anomalous results obtained by the utilization of rigid plates in the supports. Finally, so much the problem observed as the proposed solution, they are modeled and simulate by means of the method of finite elements.

Experimental set-up for electrical resistivity measurements at low temperature in amorphous and crystalline metallic samples

International Nuclear Information System (INIS)

Rodriquez Fernandez, J.M.; Lopez Sanchez, R.J.; Gomez-Sal, J.C.

1986-01-01

The experimental set-up to measure the thermal variation of the electrical resistivity between 10.5 K and 300 K, has been developed. A four probe A.C. method with a synchronous-detection (lock'in) technique were the idoneous for our proposes. We have designed a new type of pressure sample-holder adopted to the CS-202 type cryostat. The measurements performed on samples already known have allowed us to determine the sensitivity of our experiments, which is Δ ρ/ρ=2x10 -4 . The measurements performed in the new Y 3 Rh 2 Si 2 compound which at 10 K has no magnetic ordering, are also presented. (author)

Hall effect measurement for precise sheet resistance and thickness evaluation of Ruthenium thin films using non-equidistant four-point probes

Directory of Open Access Journals (Sweden)

Frederik Westergaard Østerberg

2018-05-01

Full Text Available We present a new micro Hall effect measurement method using non-equidistant electrodes. We show theoretically and verify experimentally that it is advantageous to use non-equidistant electrodes for samples with low Hall sheet resistance. We demonstrate the new method by experiments where Hall sheet carrier densities and Hall mobilities of Ruthenium thin films (3-30 nm are determined. The measurements show that it is possible to measure Hall mobilities as low as 1 cm2V−1s−1 with a relative standard deviation of 2-3%. We show a linear relation between measured Hall sheet carrier density and film thickness. Thus, the method can be used to monitor thickness variations of ultra-thin metal films.

Evaluation of pavement skid resistance using high speed texture measurement

Directory of Open Access Journals (Sweden)

Jay N. Meegoda

2015-12-01

Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

Monitoring Freeze Thaw Transitions in Arctic Soils using Complex Resistivity Method

Science.gov (United States)

Wu, Y.; Hubbard, S. S.; Ulrich, C.; Dafflon, B.; Wullschleger, S. D.

2012-12-01

The Arctic region, which is a sensitive system that has emerged as a focal point for climate change studies, is characterized by a large amount of stored carbon and a rapidly changing landscape. Seasonal freeze-thaw transitions in the Arctic alter subsurface biogeochemical processes that control greenhouse gas fluxes from the subsurface. Our ability to monitor freeze thaw cycles and associated biogeochemical transformations is critical to the development of process rich ecosystem models, which are in turn important for gaining a predictive understanding of Arctic terrestrial system evolution and feedbacks with climate. In this study, we conducted both laboratory and field investigations to explore the use of the complex resistivity method to monitor freeze thaw transitions of arctic soil in Barrow, AK. In the lab studies, freeze thaw transitions were induced on soil samples having different average carbon content through exposing the arctic soil to temperature controlled environments at +4 oC and -20 oC. Complex resistivity and temperature measurements were collected using electrical and temperature sensors installed along the soil columns. During the laboratory experiments, resistivity gradually changed over two orders of magnitude as the temperature was increased or decreased between -20 oC and 0 oC. Electrical phase responses at 1 Hz showed a dramatic and immediate response to the onset of freeze and thaw. Unlike the resistivity response, the phase response was found to be exclusively related to unfrozen water in the soil matrix, suggesting that this geophysical attribute can be used as a proxy for the monitoring of the onset and progression of the freeze-thaw transitions. Spectral electrical responses contained additional information about the controls of soil grain size distribution on the freeze thaw dynamics. Based on the demonstrated sensitivity of complex resistivity signals to the freeze thaw transitions, field complex resistivity data were collected over

Magnetic Measuring Instrumentation with Radiation-Resistant Hall Sensors for Fusion Reactors: Experience of Testing at JET

Czech Academy of Sciences Publication Activity Database

Bolshakova, I.; Quercia, A.; Coccorese, V.; Murari, A.; Holyaka, R.; Ďuran, Ivan; Viererbl, L.; Konopleva, R.; Yerashok, V.

2012-01-01

Roč. 59, č. 4 (2012), s. 1224-1231 ISSN 0018-9499. [International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications. Ghent, 06.06.2011-09.06.2011] R&D Projects: GA ČR GAP205/10/2055 Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma * tokamak * JET * Hall probes * radiation resistance Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.219, year: 2012

An encoding readout method used for Multi-gap Resistive Plate Chambers (MRPCs) for muon tomography

Science.gov (United States)

Yue, X.; Zeng, M.; Wang, Y.; Wang, X.; Zeng, Z.; Zhao, Z.; Cheng, J.

2014-09-01

A muon tomography facility has been built in Tsinghua University. Because of the low flux of cosmic muon, an encoding readout method, based on the fine-fine configuration, was implemented for the 2880 channels induced signals from the Multi-gap Resistive Plate Chamber (MRPC) detectors. With the encoding method, the number of the readout electronics was dramatically reduced and thus the complexity and the cost of the facility was reduced, too. In this paper, the details of the encoding method, and the overall readout system setup in the muon tomography facility are described. With the commissioning of the facility, the readout method works well. The spatial resolution of all MRPC detectors are measured with cosmic muon and the preliminary imaging result are also given.

An encoding readout method used for Multi-gap Resistive Plate Chambers (MRPCs) for muon tomography

International Nuclear Information System (INIS)

Yue, X; Zeng, M; Wang, Y; Wang, X; Zeng, Z; Zhao, Z; Cheng, J

2014-01-01

A muon tomography facility has been built in Tsinghua University. Because of the low flux of cosmic muon, an encoding readout method, based on the fine-fine configuration, was implemented for the 2880 channels induced signals from the Multi-gap Resistive Plate Chamber (MRPC) detectors. With the encoding method, the number of the readout electronics was dramatically reduced and thus the complexity and the cost of the facility was reduced, too. In this paper, the details of the encoding method, and the overall readout system setup in the muon tomography facility are described. With the commissioning of the facility, the readout method works well. The spatial resolution of all MRPC detectors are measured with cosmic muon and the preliminary imaging result are also given

Laboratory methods for diagnosis and detection of drug resistant ...

African Journals Online (AJOL)

Data source: Published series of peer reviewed journals and manuals written on laboratory methods that are currently used for diagnosis and detection of drug resistance of Mycobacterium tuberculosis complex were reviewed using the index medicus, pubmed and medline search. Conventional bacteriological microscopy ...

A Comparison of Proliferation Resistance Measures of Misuse Scenarios Using a Markov Approach

International Nuclear Information System (INIS)

Yue, M.; Cheng, L.-Y.; Bari, R.

2008-01-01

Misuse of declared nuclear facilities is one of the important proliferation threats. The robustness of a facility against these threats is characterized by a number of proliferation resistance (PR) measures. This paper evaluates and compares PR measures for several misuse scenarios using a Markov model approach to implement the pathway analysis methodology being developed by the PR and PP (Proliferation Resistance and Physical Protection) Expert Group. Different misue strategies can be adopted by a proliferator and each strategy is expected to have different impacts on the proliferator's success. Selected as the probabilistic measure to represent proliferation resistance, the probabilities of the proliferator's success of misusing a hypothetical ESFR (Example Sodium Fast Reactor) facility system are calculated using the Markov model based on the pathways constructed for individual misuse scenarios. Insights from a comparison of strategies that are likely to be adopted by the proliferator are discussed in this paper.

Compared performance of penetrometers and effect of soil water content on penetration resistance measurements

Directory of Open Access Journals (Sweden)

Edison Aparecido Mome Filho

2014-06-01

Full Text Available Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode in the field identification of compacted, highly mechanized sugarcane areas, considering the influence of soil water volumetric content (θ on soil penetration resistance (PR. Three sugarcane fields on a Rhodic Eutrudrox were chosen, under a sequence of harvest systems: one manual harvest (1ManH, one mechanized harvest (1MH and three mechanized harvests (3MH. The different degrees of mechanization were associated to cumulative compaction processes. An electronic penetrometer was used on PR measurements, so that the rod was introduced into the soil by hand (Manual and by an electromechanical motor (Auto. The θ was measured in the field with a soil moisture sensor. Results showed an effect of θ on PR measurements and that regression models must be used to correct data before comparing harvesting systems. The rod introduction modes resulted in different mean PR values, where the "Manual" overestimated PR compared to the "Auto" mode at low θ.

Multilayer Steel Materials Deformation Resistance and Roll Force Measurement

Directory of Open Access Journals (Sweden)

A. G. Kolesnikov

2014-01-01

Full Text Available To create new types of cars, raise their reliability, gain operational life, and decrease in metal consumption of products it is necessary to improve mechanical, physical, and also special properties of the constructional materials applied in mechanical engineering. Presently, there are intensive researches and developments under way to create materials with ultrafine-grained structure (the sizes of grains in their crystal lattice make less than 1 micron in one of the measurements.BMSTU developed a manufacturing technology of multilayer steel sheets with steady ultrafine-grained structure based on the multiple hot rolling of billet as a composition consisting of the alternating metal sheets. A principled condition for implementation of such technology is existence of different crystallographic modifications in the adjoining sheets of the composition at specified temperature of rolling.Power parameters of rolling are important technical characteristics of the process. Usually, to determine a deformation resistance value when rolling the diverse multilayer materials, is used the actual resistance value averaging in relation to the components of the composition. The aim of this work is a comparative analysis of known calculated dependences with experimental data when rolling the 100-layer samples. Objects of research were the 100-layer compositions based on the alternating layers of steel 08H18N10 and U8.Experimental samples represented the vacuumized capsules with height, width, and length of 53 mm x 53 mm x 200 mm, respectively, in which there were the 100-layer packs from sheets, each of 0.5 mm, based on the composition of steels (U8+08H18N10. Rolling was made on the double-high mill with rolls of 160 mm in diameter during 19 passes to the thickness of 7 mm with the speed of 0,1 m/s. Relative sinking in each pass was accepted to be equal 10±2,5%. Rolling forces were measured by the strain-gauging method using the measuring cells, located under

Resistivity measurements on the neutron irradiated detector grade silicon materials

Energy Technology Data Exchange (ETDEWEB)

Li, Zheng

1993-11-01

Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

Residual Resistivity Ratio (RRR) Measurements of LHC Superconducting NbTi Cable Strands

CERN Document Server

Charifoulline, Z

2006-01-01

The Rutherford-type superconducting NbTi cables of the LHC accelerator are currently manufactured by six industrial companies. As a part of the acceptance tests, the Residual Resistivity Ratio (RRR) of superconducting strands is systematically measured on virgin strands to qualify the strands before cabling and on extracted strands to qualify the cables and to check the final heat treatment (controlled oxidation to control interstrand resistance). More than 12000 samples of virgin and extracted strands have been measured during last five years. Results show good correlation with the measurements done by the companies and reflect well the technological process of cable production (strand annealing, cabling, cable heat treatment). This paper presents a description of the RRR-test station and the measurement procedure, the summary of the results over all suppliers and finally the correlation between RRR-values of the cables and the magnets.

Development of Methods for Genetic Assessment of Antibiotic Resistance In Animal Herds

DEFF Research Database (Denmark)

Schmidt, Gunilla Veslemøy

with a parallel selection for resistant bacteria. Since the hazards related to antibiotic resistance development have been recognized, the prudent use of antibiotics has been in focus, especially concerning their use in animal production. For many years antibiotics have been, and still are, recklessly used...... in the animal production especially in the form of growth promoters. Due to the associated risks of resistant zoonotic bacteria transmission from animals to humans, it is of interest to keep antibiotic use and antibiotic resistance under strict surveillance.This PhD study was based on the development of real......-time PCR (qPCR) assays that supply an easy and rapid method for quantifying antibiotic resistance levels in animal herds. The pig production is accountable for a large portion of the antibiotics used for food producing animals in Denmark. Therefore, the antibiotic resistance genes included in this study...

New equivalent-electrical circuit model and a practical measurement method for human body impedance.

Science.gov (United States)

Chinen, Koyu; Kinjo, Ichiko; Zamami, Aki; Irei, Kotoyo; Nagayama, Kanako

2015-01-01

Human body impedance analysis is an effective tool to extract electrical information from tissues in the human body. This paper presents a new measurement method of impedance using armpit electrode and a new equivalent circuit model for the human body. The lowest impedance was measured by using an LCR meter and six electrodes including armpit electrodes. The electrical equivalent circuit model for the cell consists of resistance R and capacitance C. The R represents electrical resistance of the liquid of the inside and outside of the cell, and the C represents high frequency conductance of the cell membrane. We propose an equivalent circuit model which consists of five parallel high frequency-passing CR circuits. The proposed equivalent circuit represents alpha distribution in the impedance measured at a lower frequency range due to ion current of the outside of the cell, and beta distribution at a high frequency range due to the cell membrane and the liquid inside cell. The calculated values by using the proposed equivalent circuit model were consistent with the measured values for the human body impedance.

Nonlocal nature of the resistance in classical ballistic transport

International Nuclear Information System (INIS)

Sukhorukov, E.V.; Levinson, I.B.

1990-01-01

An investigation is made of the resistance of ballistic microstructures formed in the two-dimensional electron gas of a GaAs/AlGaAs heterojunction representing combinations of long channels. It is shown that the nonlocal nature of the resistance (dependence on the measurement method) is unrelated to the quantum nature of the electron behavior, but is solely due to the ballistic nature of microstructures and does not disappear in the classical limit. An analog of the Landauer equation is obtained for the resistance measured by the four-probe method allowing for the geometry of the measuring probes

Multimodal Dispersion of Nanoparticles: A Comprehensive Evaluation of Size Distribution with 9 Size Measurement Methods.

Science.gov (United States)

Varenne, Fanny; Makky, Ali; Gaucher-Delmas, Mireille; Violleau, Frédéric; Vauthier, Christine

2016-05-01

Evaluation of particle size distribution (PSD) of multimodal dispersion of nanoparticles is a difficult task due to inherent limitations of size measurement methods. The present work reports the evaluation of PSD of a dispersion of poly(isobutylcyanoacrylate) nanoparticles decorated with dextran known as multimodal and developed as nanomedecine. The nine methods used were classified as batch particle i.e. Static Light Scattering (SLS) and Dynamic Light Scattering (DLS), single particle i.e. Electron Microscopy (EM), Atomic Force Microscopy (AFM), Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle Tracking Analysis (NTA) and separative particle i.e. Asymmetrical Flow Field-Flow Fractionation coupled with DLS (AsFlFFF) size measurement methods. The multimodal dispersion was identified using AFM, TRPS and NTA and results were consistent with those provided with the method based on a separation step prior to on-line size measurements. None of the light scattering batch methods could reveal the complexity of the PSD of the dispersion. Difference between PSD obtained from all size measurement methods tested suggested that study of the PSD of multimodal dispersion required to analyze samples by at least one of the single size particle measurement method or a method that uses a separation step prior PSD measurement.

Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

Science.gov (United States)

Vail, W.B. III.

1989-11-21

Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas are present. Lithological characteristics of the formation such as the presence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes. 48 figs.

Corrosion Resistance Evaluation of Welded AISI 316 Stainless Steel by Electrochemical Method

International Nuclear Information System (INIS)

Baik, Shin Young; Kim, Kwan Hyu

1990-01-01

Electrochemical potentiokinetic polarization technique is known as quantitative, non-destructive and a rapid method for detecting sensitization and is essentially suitable for use in industrial fields and as laboratory research tools. In this study, electrochemical method was tested as a convenient means of the corrosion resistance evaluation for AISI 316L and 316 stainless steel(SS) and their welded sections. The sections were welded by TIG, MIG, CO 2 and ARC in 0.5N HCl as well as 1N H 2 SO 4 electrolyte with or without 0.01N KSCN. The results confirmed that electrochemical method could be used conveniently for corrosion resistance evaluation except reactivation aspect

Real-time particle volume fraction measurement in centrifuges by wireless electrical resistance detector

International Nuclear Information System (INIS)

Nagae, Fumiya; Okawa, Kazuya; Matsuno, Shinsuke; Takei, Masahiro; Zhao Tong; Ichijo, Noriaki

2015-01-01

In this study, wireless electrical resistance detector is developed as first step in order to develop electrical resistance tomography (ERT) that are attached wireless communication, and miniaturized. And the particle volume fraction measurement results appropriateness is qualitatively examined. The real-time particle volume fraction measurement is essential for centrifuges, because rotational velocity and supply should be controlled based on the results in order to obtain the effective separation, shorten process time and save energy. However, a technique for the particle volume fraction measurement in centrifuges has not existed yet. In other words, the real-time particle volume fraction measurement in centrifuges becomes innovative technologies. The experiment device reproduces centrifugation in two-phase using particle and salt solution as measuring object. The particle concentration is measured changing rotational velocity, supply and measurement section position. The measured concentration changes coincide with anticipated tendency of concentration changes. Therefore the particle volume fraction measurement results appropriateness are qualitatively indicated. (author)

In situ measurement system of electric resistivity for outcrop investigation; Roto de shiyodekiru denkihi teiko keisoku system

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, K; Tamura, T [Osaka City Univ., Osaka (Japan). Faculty of Science; Morikawa, T [Osaka Prefectural Government, Osaka (Japan)

1997-05-27

A simplified electrical resistivity measuring device has been developed as a trial for field and laboratory uses, and some measurements were conducted. For this device, four probe electrodes are penetrated in the clay specimen, to calculate the resistivity from the voltage between both ends of the reference resistance connected with current electrodes in a series and the voltage between intermediate two voltage electrodes. It can be used in the field measurements. For the measurements, specimens of marine and lacustrine clayey sediments with clear stratigraphic levels in southern Osaka Group were used. In the laboratory, in addition to basic physical tests, diatom analysis and measurements of conductivity of clay suspension were also conducted. As a result of the experiments, the electric resistivity of marine clay obtained at the outcrop was lower than lacustrine clay as expected. The value of the former was a half of that of the latter. The frequency dependence in the high frequency region above 1 MHz was the reverse. The difference in electrical resistivity values between non-agitated specimens was about four times. The electrical resistivity of clay suspensions varied in two orders. 3 refs., 9 figs.

Seismic passive earth resistance using modified pseudo-dynamic method

Science.gov (United States)

Pain, Anindya; Choudhury, Deepankar; Bhattacharyya, S. K.

2017-04-01

In earthquake prone areas, understanding of the seismic passive earth resistance is very important for the design of different geotechnical earth retaining structures. In this study, the limit equilibrium method is used for estimation of critical seismic passive earth resistance for an inclined wall supporting horizontal cohesionless backfill. A composite failure surface is considered in the present analysis. Seismic forces are computed assuming the backfill soil as a viscoelastic material overlying a rigid stratum and the rigid stratum is subjected to a harmonic shaking. The present method satisfies the boundary conditions. The amplification of acceleration depends on the properties of the backfill soil and on the characteristics of the input motion. The acceleration distribution along the depth of the backfill is found to be nonlinear in nature. The present study shows that the horizontal and vertical acceleration distribution in the backfill soil is not always in-phase for the critical value of the seismic passive earth pressure coefficient. The effect of different parameters on the seismic passive earth pressure is studied in detail. A comparison of the present method with other theories is also presented, which shows the merits of the present study.

Comparison between the boundary layer and global resistivity methods for tearing modes in reversed field configurations

International Nuclear Information System (INIS)

Santiago, M.A.M.

1987-01-01

A review of the problem of growth rate calculations for tearing modes in field reversed Θ-pinches is presented. Its shown that in the several experimental data, the methods used for analysing the plasma with a global finite resistivity has a better quantitative agreement than the boundary layer analysis. A comparative study taking into account the m = 1 resistive kindmode and the m = 2 mode, which is more dangerous for the survey of rotational instabilities of the plasma column is done. It can see that the imaginary component of the eigenfrequency, which determinates the growth rate, has a good agreement with the experimental data and the real component is different from the rotational frequency as it has been measured in some experiments. (author) [pt

Impact of Air Entraining Method on the Resistance of Concrete to Internal Cracking

Science.gov (United States)

Wawrzeńczyk, Jerzy; Molendowska, Agnieszka

2017-10-01

This paper presents the test results of air entrained concrete mixtures made at a constant W/C ratio of 0.44. Three different air entraining agents were used: polymer microspheres, glass microspheres and a conventional air entraining admixture. The aim of this study was to compare the effectiveness of the air entraining methods. Concrete mixture tests were performed for consistency (slump test), density and, in the case of AEA series, air content by pressure method. Hardened concrete tests were performed for compressive strength, water absorption, resistance to chloride ingress, and freeze-thaw durability - resistance to internal cracking tests were conducted in accordance with PN-88/B-06250 on cube specimens and with the modified ASTM C666 A test method on beam specimens; porosity characteristics (A, A300, \\bar L) were determined to PN-EN 480-11:1998. No significant mass and length changes were recorded for the concrete air entrained with the conventional methods or with polymer microspheres. The results indicate that polymer microspheres are a very good alternative to traditional air entraining methods for concrete, providing effective air entrainment and protection from freezing and thawing. The glass microsphere-based concretes showed insufficient freeze-thaw resistance. The test results indicate that both the conventional methods (AEA) and the air entrainment by polymer microspheres are effective air entraining methods. It has to be noted that in the case of the use of polymer microspheres, a comparable value of \\bar L and a very good freeze-thaw resistance can be achieved at a noticeably lower air and micropore contents and at lower strength loss.

Comparison of Resistant and Susceptible Strains of Trichomons vaginalis to Metronidazole Using PCR Method

Directory of Open Access Journals (Sweden)

M Fallah

2012-09-01

Full Text Available Background: Metronidazole is drug of choice recommended by WHO for treatment of trichomoniasis, however, some reports claims drug resistance in Trichomonas vaginalis isolates recently. The objective of this study was to determine the minimum lethal concentration (MLC of metronidazole in resistant and sensitive strains, as well as genetic patterns of these stains by PCR method. Methods: From February 2006 to March 2007, in a cross sectional study, clinical and wet mount examination of vaginal smear along with culture were performed on 683 women attending to public and private outpatient clinics in Hamadan. Trichomoniasis marked based on major clinical symptoms. Diagnosis confirmed using wet mount microscopically and culture in Diamond medium. A serial concentration of metronidazole was provided and all isolated Trichomonas strains (resistant and sensitive tested by standard method. Finally, all sensitive and resistant strains examined by PCR technique. Results: Only 15/683, (2.2% of patients clinically diagnosed trichomonal vaginitis were positive for T. vaginalis by wet smear and culture. The minimum lethal concentration (MLC for clinically sensitive isolates was 25 µg/ml; however, this concentration for resistant isolates was 200 µg/ml after 24 h and 100 µg/ml after 50 h. The results of PCR examination of DNA from sensitive and resistant isolates had same pattern. The lanes appeared by two primers were 98 bp and 261 bp for both clinically sensitive and resistant strains. Conclusion: Resistance to metronidazole in T. vaginalis has not relation to genetic variations and might be related to some physiologic pathways of organism.

Method of manufacturing a shapeable short-resistant capacitor

Science.gov (United States)

Taylor, Ralph S.; Myers, John D.; Baney, William J.

2013-04-02

A method that employs a novel combination of conventional fabrication techniques provides a ceramic short-resistant capacitor that is bendable and/or shapeable to provide a multiple layer capacitor that is extremely compact and amenable to desirable geometries. The method allows thinner and more flexible ceramic capacitors to be made. The method includes forming a first thin metal layer on a substrate; depositing a thin, ceramic dielectric layer over the metal layer; depositing a second thin metal layer over the dielectric layer to form a capacitor exhibiting a benign failure mode; and separating the capacitor from the substrate. The method may also include bending the resulting capacitor into a serpentine arrangement with gaps between the layers that allow venting of evaporated electrode material in the event of a benign failure.

Hastes instrumentadas para a mensuração da resistência mecânica do solo Instrumented shanks for soil mechanical resistance measurements

Directory of Open Access Journals (Sweden)

Viacheslav I. Adamchuk

2006-04-01

Full Text Available A presença de camada de solo compactada pode significar sérios problemas ao desenvolvimento do sistema radicular das culturas em geral. A correção pode ser feita por métodos biológicos ou mecânicos. Uma das formas de diagnóstico da sua presença é com o uso de penetrômetros que exigem tempo considerável para a obtenção de dados. Com o advento dos recursos de espacialização das informações na forma de mapas, a necessidade de amostragem passou a ser ainda maior. Este trabalho reporta a busca de uma solução alternativa ao uso do penetrômetro. Envolve a geração de mapas de resistência mecânica do solo ao deslocamento de uma haste em três profundidades, baseado em três hastes instrumentadas, um receptor de GPS e um sistema de aquisição de dados. O sistema é acoplado a uma barra porta-ferramenta montada no engate de três pontos do trator. A configuração mostrou ser mecanicamente bastante simples e confiável. Dados de um teste inicial em campo demonstraram que o sistema pode produzir mapas que denotam a variabilidade espacial da referida resistência nas áreas amostradas, com alta resolução, densidade de amostragem elevada e com capacidade operacional ainda mais elevada se comparada com levantamentos feitos com métodos convencionais.The presence of soil compaction may be considered a serious problem for the development of crop root systems. It can be alleviated by biological or mechanical methods (such as tillage. One of the most popular diagnostic methods is based on standardized cone penetrometer measurements, which requires a considerable amount of time to obtain the data. With the advent of site-specific field management, high-density measurements have become a necessity. This work reports on an alternative approach to use a cone penetromenter. It involves the generation of maps of soil mechanical resistance at three depths using three instrumented blades, a GPS receiver and a data logger. The system is attached

A Novel Method of Modeling the Deformation Resistance for Clad Sheet

International Nuclear Information System (INIS)

Hu Jianliang; Yi Youping; Xie Mantang

2011-01-01

Because of the excellent thermal conductivity, the clad sheet (3003/4004/3003) of aluminum alloy is extensively used in various heat exchangers, such as radiator, motorcar air conditioning, evaporator, and so on. The deformation resistance model plays an important role in designing the process parameters of hot continuous rolling. However, the complex behaviors of the plastic deformation of the clad sheet make the modeling very difficult. In this work, a novel method for modeling the deformation resistance of clad sheet was proposed by combining the finite element analysis with experiments. The deformation resistance model of aluminum 3003 and 4004 was proposed through hot compression test on the Gleeble-1500 thermo-simulation machine. And the deformation resistance model of clad sheet was proposed through finite element analysis using DEFORM-2D software. The relationship between cladding ratio and the deformation resistance was discussed in detail. The results of hot compression simulation demonstrate that the cladding ratio has great effects on the resistance of the clad sheet. Taking the cladding ratio into consideration, the mathematical model of the deformation resistance for clad sheet has been proved to have perfect forecasting precision of different cladding ratio. Therefore, the presented model can be used to predict the rolling force of clad sheet during the hot continuous rolling process.

Microstructure characterization and corrosion resistance properties of Pb-Sb alloys for lead acid battery spine produced by different casting methods

Science.gov (United States)

Baig, Muneer; Alam, Mohammad Asif; Alharthi, Nabeel

2018-01-01

The aim of this study is to find out the microstructure, hardness, and corrosion resistance of Pb-5%Sb spine alloy. The alloy has been produced by high pressure die casting (HPDC), medium pressure die casting (AS) and low pressure die casting (GS) methods, respectively. The microstructure was characterized by using optical microscopy and scanning electron microscopy (SEM). The hardness was also reported. The corrosion resistance of the spines in 0.5M H2SO4 solution has been analyzed by measuring the weight loss, impedance spectroscopy and the potentiodynamic polarization techniques. It has been found that the spine produced by HPDC has defect-free fine grain structure resulting improvement in hardness and excellent corrosion resistance. PMID:29668709

A review of plant protection against the olive fly (Bactrocera oleae (Rossi, 1790 Gmelin and molecular methods to monitor the insecticide resistance alleles

Directory of Open Access Journals (Sweden)

Matjaž Hladnik

2017-01-01

Full Text Available Olive fly (Bactrocera oleae (Rossi, 1790 Gmelin is one of the most important olive pests worldwide. Most plant protection measures are based on insecticides, especially organophosphates, pyrethroids, and recently a spinosad. Insecticides are used as cover sprays or in more environmentally friendly methods in which insecticides are used in combination with attractants and pheromones as bait sprays or for mass trapping. However, due to negative impacts of insecticides to environment, new plant protection methods are constantly developing with the aim to lower the consumption of insecticides or even to eliminate them by biological control with entomopathogenic organisms, sterile insect technique (SIT, or transgenic method RIDL (release of insects carrying a dominant lethal. However, these methods need to be improved in order to guarantee adequate protection. Alternative methods than those traditionally used are required due to long term usage causing the development of resistance to the insecticides, ultimately lowering their effectiveness. Molecular methods for monitoring the frequencies of resistant alleles and the current status of resistance alleles in olive growing countries are reviewed here.

The Comparison of Two Methods of Exercise (intense interval training and concurrent resistance- endurance training on Fasting Sugar, Insulin and Insulin Resistance in Women with Mellitus Diabetes

Directory of Open Access Journals (Sweden)

F Bazyar

2016-05-01

Full Text Available Background & aim: Exercise is an important component of health and an integral approach to the management of diabetes mellitus. The purpose of this study was to compare the effects of intense interval training and concurrent resistance- endurance training on fasting sugar, insulin and insulin resistance in women with mellitus diabetes.   Methods: Fifty-two overweight female diabetic type 2 patients (aged 45-60 years old with fasting blood glucose≥ 126 mg/dl were selected to participate in the present study. Participants were assigned to intense interval training group (N=17, concurrent resistance- endurance training group (N=17 and control group (N=18. The exercises incorporated 10 weeks of concurrent resistance- endurance training and intense interval training. Fasting blood sugar, serum insulin concentrations levels were measured. Concurrent training group trained eight weeks, three times a week of endurance training at 60% of maximum heart rate (MHR and two resistance training sessions per week with 70% of one repetition maximum (1-RM. Intense interval training group trained for eight weeks, three sessions per week for 4 to 10 repeats Wingate test on the ergometer 30s performed with maximum effort. The control group did no systematic exercise. At the end of experiment 42 subjects were succeed and completed the study period, and 10 subjects were removed due to illness and absence in the exercise sessions. Fasting blood sugar and insulin levels 24 hours before and 48 hours after the last training session was measured.   Results: The findings indicated that in periodic fasting, the blood sugar in intensive training group had a marked decrease (p= 0.000 however, the fasting blood sugar of exercise and power stamina groups reduced significantly (p=0.062. The results showed no significant difference between the groups (171/0 p =0.171. Fasting insulin (p <0.001 and insulin resistance (0001/0 = p=0.001 in periodic intensive training group were

A Simple Method for the Assessment of Fusarium Head Blight Resistance in Korean Wheat Seedlings Inoculated with Fusarium graminearum

Directory of Open Access Journals (Sweden)

Sanghyun Shin

2014-03-01

Full Text Available Fusarium head blight (FHB; scab caused mainly by Fusarium graminearum is a devastating disease of wheat and barley around the world. FHB causes yield reductions and contamination of grain with trichothecene mycotoxins such as deoxynivalenol (DON which are a major health concern for humans and animals. The objective of this research was to develop an easy seed or seedling inoculation assay, and to compare these assays with whole plant resistance of twenty-nine Korean winter wheat cultivars to FHB. The clip-dipping assay consists of cutting off the coleoptiles apex, dipping the coleoptiles apex in conidial suspension, covering in plastic bag for 3 days, and measuring the lengths of lesions 7 days after inoculation. There were significant cultivar differences after inoculation with F. graminearum in seedling relative to the controls. Correlation coefficients between the lesion lengths of clip-dipping inoculation and FHB Type II resistance from adult plants were significant (r=0.45; P<0.05. Results from two other seedling inoculation methods, spraying and pin-point inoculation, were not correlated with adult FHB resistance. Single linear correlation was not significant between seed germination assays (soaking and soak-dry and FHB resistance (Type I and Type II, respectively. These results showed that clip-dipping inoculation method using F. graminearum may offer a real possibility of simple, rapid, and reliable for the early screening of FHB resistance in wheat.

Methodology for assessing the probability of corrosion in concrete structures on the basis of half-cell potential and concrete resistivity measurements.

Science.gov (United States)

Sadowski, Lukasz

2013-01-01

In recent years, the corrosion of steel reinforcement has become a major problem in the construction industry. Therefore, much attention has been given to developing methods of predicting the service life of reinforced concrete structures. The progress of corrosion cannot be visually assessed until a crack or a delamination appears. The corrosion process can be tracked using several electrochemical techniques. Most commonly the half-cell potential measurement technique is used for this purpose. However, it is generally accepted that it should be supplemented with other techniques. Hence, a methodology for assessing the probability of corrosion in concrete slabs by means of a combination of two methods, that is, the half-cell potential method and the concrete resistivity method, is proposed. An assessment of the probability of corrosion in reinforced concrete structures carried out using the proposed methodology is presented. 200 mm thick 750 mm  ×  750 mm reinforced concrete slab specimens were investigated. Potential E corr and concrete resistivity ρ in each point of the applied grid were measured. The experimental results indicate that the proposed methodology can be successfully used to assess the probability of corrosion in concrete structures.

Methodology for Assessing the Probability of Corrosion in Concrete Structures on the Basis of Half-Cell Potential and Concrete Resistivity Measurements

Directory of Open Access Journals (Sweden)

Lukasz Sadowski

2013-01-01

Full Text Available In recent years, the corrosion of steel reinforcement has become a major problem in the construction industry. Therefore, much attention has been given to developing methods of predicting the service life of reinforced concrete structures. The progress of corrosion cannot be visually assessed until a crack or a delamination appears. The corrosion process can be tracked using several electrochemical techniques. Most commonly the half-cell potential measurement technique is used for this purpose. However, it is generally accepted that it should be supplemented with other techniques. Hence, a methodology for assessing the probability of corrosion in concrete slabs by means of a combination of two methods, that is, the half-cell potential method and the concrete resistivity method, is proposed. An assessment of the probability of corrosion in reinforced concrete structures carried out using the proposed methodology is presented. 200 mm thick 750 mm  ×  750 mm reinforced concrete slab specimens were investigated. Potential Ecorr and concrete resistivity ρ in each point of the applied grid were measured. The experimental results indicate that the proposed methodology can be successfully used to assess the probability of corrosion in concrete structures.

Evaluation of the drain—source voltage effect on AlGaAs/InGaAs PHEMTs thermal resistance by the structure function method

International Nuclear Information System (INIS)

Ma Lin; Feng Shiwei; Zhang Yamin; Deng Bing; Yue Yuan

2014-01-01

The effect of drain—source voltage on AlGaAs/InGaAs PHEMTs thermal resistance is studied by experimental measuring and simulation. The result shows that AlGaAs/InGaAs PHEMTs thermal resistance presents a downward trend under the same power dissipation when the drain—source voltage (V DS ) is decreased. Moreover, the relatively low V DS and large drain—source current (I DS ) result in a lower thermal resistance. The chip-level and package-level thermal resistance have been extracted by the structure function method. The simulation result indicated that the high electric field occurs at the gate contact where the temperature rise occurs. A relatively low V DS leads to a relatively low electric field, which leads to the decline of the thermal resistance. (semiconductor devices)

The Application of 2-D Resistivity and Self Potential (SP) Methods in Determining the Water Flow

Science.gov (United States)

Nordiana, M. M.; Tajudeen Olugbenga, Adeeko; Afiq Saharudin, Muhamad; nabila, S.; El Hidayah Ismail, Noer

2018-04-01

Existence of water flow at urban area will decrease the shear strength and increase hydraulic conductivity of soil which finally caused subsurface problems at this area. To avoid landslide, slope instability and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. The understanding about geological condition has to be considering before construction activities be done. Six 2-D resistivity survey lines with minimum 5 m electrode spacing were executed using Pole-dipole array. The field investigation such as borehole was carried out at multiple locations in the area where the 2-D resistivity method have been conducted. The directions and intensities of the water were evaluated with self-potential (SP) method. Subsequently, the results from borehole were used to verify the results of electrical resistivity method. Interpretation of 2-D resistivity data showed a low resistivity value (ohm-m), which appears to be a zone that is fully saturated with sandy silt and this could be an influence factor the increasing water level because sandy silt is highly permeable in nature. The borehole, support the results of 2-D resistivity method relating a saturated zone in the survey area. There is a good correlation between the 2-D resistivity investigations and the results of borehole records.

within plant resistance to water flow in tomato and sweet melons

African Journals Online (AJOL)

Administrator

high pressure flow meter (HPFM) and evaporative flux (EF) methods. In the evaporative flux method, measure- ments of transpiration flux and leaf water potential were used to calculate the total resistance to water flow using. Ohm's law analogy. Measurements of tranpiration flux (Q) relationship, plant resistance calculated ...

Comparison of microstickies measurement methods. Part I, sample preparation and measurement methods

Science.gov (United States)

Mahendra R. Doshi; Angeles Blanco; Carlos Negro; Gilles M. Dorris; Carlos C. Castro; Axel Hamann; R. Daniel Haynes; Carl Houtman; Karen Scallon; Hans-Joachim Putz; Hans Johansson; R.A. Venditti; K. Copeland; H.-M. Chang

2003-01-01

Recently, we completed a project on the comparison of macrostickies measurement methods. Based on the success of the project, we decided to embark on this new project on comparison of microstickies measurement methods. When we started this project, there were some concerns and doubts principally due to the lack of an accepted definition of microstickies. However, we...

The association between measurements of antimicrobial use and resistance in the faeces microbiota of finisher batches.

Science.gov (United States)

Andersen, V D; DE Knegt, L V; Munk, P; Jensen, M S; Agersø, Y; Aarestrup, F M; Vigre, H

2017-10-01

The objectives were to present three approaches for calculating antimicrobial (AM) use in pigs that take into account the rearing period and rearing site, and to study the association between these measurements and phenotypical resistance and abundance of resistance genes in faeces samples from 10 finisher batches. The AM use was calculated relative to the rearing period of the batches as (i) 'Finisher Unit Exposure' at unit level, (ii) 'Lifetime Exposure' at batch level and (iii) 'Herd Exposure' at herd level. A significant effect on the occurrence of tetracycline resistance measured by cultivation was identified for Lifetime Exposure for the AM class: tetracycline. Furthermore, for Lifetime Exposure for the AM classes: macrolide, broad-spectrum penicillin, sulfonamide and tetracycline use as well as Herd Unit Exposure for the AM classes: aminoglycoside, lincosamide and tetracycline use, a significant effect was observed on the occurrence of genes coding for the AM resistance classes: aminoglycoside, lincosamide, macrolide, β-lactam, sulfonamide and tetracycline. No effect was observed for Finisher Unit Exposure. Overall, the study shows that Lifetime Exposure is an efficient measurement of AM use in finisher batches, and has a significant effect on the occurrence of resistance, measured either by cultivation or metagenomics.

Resistance test of high-speed ship by means of attitude control method. Part 2; Shisei seigyo hoshiki ni yoru kosokutei no teiko shiken. 2

Energy Technology Data Exchange (ETDEWEB)

Hayashida, S [Nagasaki Institute of Applied Science, Nagasaki (Japan)

1996-04-10

The previous paper has proposed a resistance test method by controlling the attitude of a high-speed model ship using a personal computer without making a data base. For this method, the fluid force acting on the hull of model ship is measured, to change its attitude based on the measurement, and then, the fluid force is measured again, to change the attitude again. The traveling attitude is created by repeating this, to measure the force acting on the hull. Since the attitude is changed by calculating using the fluid force measured, various factors can be considered in the calculation process. For example, a test with an arbitrary displacement in an arbitrary position of center of gravity can be conducted in spite of actual displacement and position of center of gravity of the model ship. A test for a high-speed ship was conducted through this method, to obtain nearly satisfactory results compared with a usual resistance test. Occasionally, a lot of repetitions were required to satisfy the balancing condition of the force. In this study, the improvement of testing efficiency has been planned by modifying the analyzing program. 5 refs., 7 figs., 1 tab.

Review of modern methods for continuous friction measurement on airfield pavements

Science.gov (United States)

Iwanowski, Paweł; Blacha, Krzysztof; Wesołowski, Mariusz

2018-05-01

The safety of traffic, including both road and air traffic on a ground manoeuvre area, depends on many factors. These mainly include the anti-slip properties of a road or airfield pavement on which the traffic takes place. The basic pavement parameter that determines its characteristics in terms of anti-slip properties is the skid resistance, which constitutes the ratio of the wheel downforce and the friction on the contact surface. There are currently many devices for continuous measurement of the skid resistance (Continuous Friction-Measuring Equipment - CFME) around the world. Most of them, in principle, do not vary much from one another. Most of the devices measure the measuring wheel’s downforce on the pavement and the friction on the wheel-pavement contact surface. The skid resistance is the result of this measurement. The devices vary in many aspects, such as the type and size of the used measuring tyre, pavement-wheel slip or tyre pressure. This does not mean that the results obtained from various devices mbe directly compared. On the other hand, each device allows determining the pavement’s anti-slip conditions in terms of the requirements specified for the given type of devices, thereby enabling pavement classification in these terms. The classification allows for comparing the results obtained from various measuring devices. The paper presents an overview of equipment used in Poland and around the world to measure the skid resistance on airfield pavements. The authors draw attention to the requirements for pavements in terms of their roughness, with division into road and airfield pavements.

A new method for calculating gas saturation of low-resistivity shale gas reservoirs

Directory of Open Access Journals (Sweden)

Jinyan Zhang

2017-09-01

Full Text Available The Jiaoshiba shale gas field is located in the Fuling area of the Sichuan Basin, with the Upper Ordovician Wufeng–Lower Silurian Longmaxi Fm as the pay zone. At the bottom of the pay zone, a high-quality shale gas reservoir about 20 m thick is generally developed with high organic contents and gas abundance, but its resistivity is relatively low. Accordingly, the gas saturation calculated by formulas (e.g. Archie using electric logging data is often much lower than the experiment-derived value. In this paper, a new method was presented for calculating gas saturation more accurately based on non-electric logging data. Firstly, the causes for the low resistivity of shale gas reservoirs in this area were analyzed. Then, the limitation of traditional methods for calculating gas saturation based on electric logging data was diagnosed, and the feasibility of the neutron–density porosity overlay method was illustrated. According to the response characteristics of neutron, density and other porosity logging in shale gas reservoirs, a model for calculating gas saturation of shale gas was established by core experimental calibration based on the density logging value, the density porosity and the difference between density porosity and neutron porosity, by means of multiple methods (e.g. the dual-porosity overlay method by optimizing the best overlay coefficient. This new method avoids the effect of low resistivity, and thus can provide normal calculated gas saturation of high-quality shale gas reservoirs. It works well in practical application. This new method provides a technical support for the calculation of shale gas reserves in this area. Keywords: Shale gas, Gas saturation, Low resistivity, Non-electric logging, Volume density, Compensated neutron, Overlay method, Reserves calculation, Sichuan Basin, Jiaoshiba shale gas field

Two-point concrete resistivity measurements: interfacial phenomena at the electrode–concrete contact zone

International Nuclear Information System (INIS)

McCarter, W J; Taha, H M; Suryanto, B; Starrs, G

2015-01-01

Ac impedance spectroscopy measurements are used to critically examine the end-to-end (two-point) testing technique employed in evaluating the bulk electrical resistivity of concrete. In particular, this paper focusses on the interfacial contact region between the electrode and specimen and the influence of contacting medium and measurement frequency on the impedance response. Two-point and four-point electrode configurations were compared and modelling of the impedance response was undertaken to identify and quantify the contribution of the electrode–specimen contact region on the measured impedance. Measurements are presented in both Bode and Nyquist formats to aid interpretation. Concretes mixes conforming to BSEN206-1 and BS8500-1 were investigated which included concretes containing the supplementary cementitious materials fly ash and ground granulated blast-furnace slag. A measurement protocol is presented for the end-to-end technique in terms of test frequency and electrode–specimen contacting medium in order to minimize electrode–specimen interfacial effect and ensure correct measurement of bulk resistivity. (paper)

Cross-bidge Kelvin resistor (CBKR) structures for measurement of low contact resistances

NARCIS (Netherlands)

Stavitski, N.; Klootwijk, J.H.; van Zeijl, H.W.; Boksteen, B.K.; Boksteen, B.K.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.

2007-01-01

A convenient test structure for measurement of the specific contact resistance (�?c) of metal-semiconductor junctions is the CBKR structure. During last few decades the parasitic factors which may strongly affect the measurements accuracy for �?c < 10-6 Ω • cm2 have been sufficiently discussed and

Germination test as a fast method to detect glyphosate-resistant sourgrass

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Marcos Altomani Neves Dias

2015-01-01

Full Text Available The occurrence of weed species with different levels of resistance to glyphosate has increasingly spread in agricultural areas. In Brazil, sourgrass is among the main species presenting issues in this regard. Thus, fast and reliable methods to detect glyphosate resistance are of special interest for this specie, either for research or rational management purposes. This study was carried out to verify the feasibility of using the germination test to detect glyphosate resistance in sourgrass. The experiment was conducted with two sourgrass biotypes, with different levels of susceptibility to glyphosate. The seeds were previously imbibed in solutions composed of 0, 0.1875%, 0.25%, 0.75%, 1.5%, 3% and 6% of glyphosate during two periods, five and ten minutes, and submitted to germination tests. The results indicate the germination test as a feasible and time-saving approach to evaluate glyphosate-resistant sourgrass, with results available in seven days.

Germination test as a fast method to detect glyphosate-resistant sourgrass

Directory of Open Access Journals (Sweden)

Marcos Altomani Neves Dias

2015-09-01

Full Text Available The occurrence of weed species with different levels of resistance to glyphosate has increasingly spread in agricultural areas. In Brazil, sourgrass is among the main species presenting issues in this regard. Thus, fast and reliable methods to detect glyphosate resistance are of special interest for this specie, either for research or rational management purposes. This study was carried out to verify the feasibility of using the germination test to detect glyphosate resistance in sourgrass. The experiment was conducted with two sourgrass biotypes, with different levels of susceptibility to glyphosate. The seeds were previously imbibed in solutions composed of 0, 0.1875%, 0.25%, 0.75%, 1.5%, 3% and 6% of glyphosate during two periods, five and ten minutes, and submitted to germination tests. The results indicate the germination test as a feasible and time-saving approach to evaluate glyphosate-resistant sourgrass, with results available in seven days.

The application of DCPD method to evaluating dynamic J-R fracture resistance characteristics

International Nuclear Information System (INIS)

Yoon, Ji Hyun; Hong, Jun Hwa; Lee, Bong Sang; Chi, Se Whan; Kim, Joo Hag; Oh, Yong Jun; Kwun, Sun Chil; Oh, Jong Myung

1999-06-01

The reliable DCPD (Direct Current Potential Drop) test and data acquisition system were developed on the basis of analysis of various technical problems to accompanied with the application of DCPD method to J-R fracture resistance test. The test system contains electric insulation rod and high performance data acquisition system. The test and analysis method was applied to J-R fracture resistance test for SA516-Gr.70 steel for nuclear primary coolant system elbow. The reliabilities of test and analysis method were confirmed through the load-ratio method in case of dynamic loading test, and through the standard unloading compliance test in case of static loading test. (author). 17 refs., 1 tab., 18 figs

The application of DCPD method to evaluating dynamic J-R fracture resistance characteristics

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ji Hyun; Hong, Jun Hwa; Lee, Bong Sang; Chi, Se Whan; Kim, Joo Hag; Oh, Yong Jun; Kwun, Sun Chil; Oh, Jong Myung

1999-06-01

The reliable DCPD (Direct Current Potential Drop) test and data acquisition system were developed on the basis of analysis of various technical problems to accompanied with the application of DCPD method to J-R fracture resistance test. The test system contains electric insulation rod and high performance data acquisition system. The test and analysis method was applied to J-R fracture resistance test for SA516-Gr.70 steel for nuclear primary coolant system elbow. The reliabilities of test and analysis method were confirmed through the load-ratio method in case of dynamic loading test,and through the standard unloading compliance test in case of static loading test. (author). 17 refs., 1 tab., 18 figs.

Development of Efficient Screening Methods for Resistant Cucumber Plants to Meloidogyne incognita

Directory of Open Access Journals (Sweden)

Sung Min Hwang

2014-06-01

Full Text Available Root-knot nematodes represent a significant problem in cucumber, causing reduction in yield and quality. To develop screening methods for resistance of cucumber to root-knot nematode Meloidogyne incognita, development of root-knot nematode of four cucumber cultivars (‘Dragonsamchuk’, ‘Asiastrike’, ‘Nebakja’ and ‘Hanelbakdadaki’ according to several conditions such as inoculum concentration, plant growth stage and transplanting period was investigated by the number of galls and egg masses produced in each seedling 45 days after inoculation. There was no difference in galls and egg masses according to the tested condition except for inoculum concentration. Reproduction of the nematode on all the tested cultivars according to inoculum concentration increased in a dose-dependent manner. On the basis of the result, the optimum conditions for root-knot development on the cultivars is to transplant period of 1 week, inoculum concentration of 5,000 eggs/plant and plant growth stage of 3-week-old in a greenhouse (25 ± 5°C. In addition, under optimum conditions, resistance of 45 commercial cucumber cultivars was evaluated. One rootstock cultivar, Union was moderately resistant to the root-knot nematode. However, no significant difference was in the resistance of the others cultivar. According to the result, we suggest an efficient screening method for new resistant cucumber to the root-knot nematode, M. incognita.

Temperature radiation measuring equipment. Temperaturstrahlungsmessgeraet

Energy Technology Data Exchange (ETDEWEB)

Lotzer, W

1981-01-22

The invention is concerned with a temperature radiation measuring equipment for non-contact temperature measurement by the light intensity variation method, with a photoelectric resistance as the measuring element. By having a circuit with a transistor, the 'dark resistance' occurring in the course of time is compensated for and thus gives a genuine reading (ie. the voltage drop across the photoelectric resistance remains constant).

Clozapine-resistant schizophrenia – non pharmacological augmentation methods

Directory of Open Access Journals (Sweden)

Gałaszkiewicz Joanna

2017-12-01

Full Text Available Clozapine is the drug of choice for drug-resistant schizophrenia, but despite its use, 30-40% patients fail to achieve satisfactory therapeutic effects. In such situations, augmentation attempts are made by both pharmacological and non-pharmacological methods. To date, most of the work has been devoted to pharmacological strategies, much less to augemantation of clozapine with electroconvulsive therapy (C+ECT, transcranial direct current stimulation (tDCS or transcranial magnetic stimulation (TMS.

Methods for detecting and locating leaks in containment facilities using electrical potential data and electrical resistance tomographic imaging techniques

Science.gov (United States)

Daily, William D.; Laine, Daren L.; Laine, Edwin F.

1997-01-01

Methods are provided for detecting and locating leaks in liners used as barriers in the construction of landfills, surface impoundments, water reservoirs, tanks, and the like. Electrodes are placed in the ground around the periphery of the facility, in the leak detection zone located between two liners if present, and/or within the containment facility. Electrical resistivity data is collected using these electrodes. This data is used to map the electrical resistivity distribution beneath the containment liner between two liners in a double-lined facility. In an alternative embodiment, an electrode placed within the lined facility is driven to an electrical potential with respect to another electrode placed at a distance from the lined facility (mise-a-la-masse). Voltage differences are then measured between various combinations of additional electrodes placed in the soil on the periphery of the facility, the leak detection zone, or within the facility. A leak of liquid though the liner material will result in an electrical potential distribution that can be measured at the electrodes. The leak position is located by determining the coordinates of an electrical current source pole that best fits the measured potentials with the constraints of the known or assumed resistivity distribution.

Methods for the evaluation of antibiotic resistance in Lactobacillus isolated from fermented sausages

Directory of Open Access Journals (Sweden)

Hanna Lethycia Wolupeck

Full Text Available ABSTRACT: The present study aimed to assess the antibiotic resistance in 54 indigenous Lactobacillus plantarum isolated from artisanal fermented sausages. The confirmation of the strain species was performed by multiplex-PCR assay. Antibiotic resistance was assessed by disk diffusion (DD and Minimum Inhibitory Concentration (MIC methods. Of 54 L. plantarum, 44 strains were genotypically confirmed as L. plantarum and 3 as Lactobacillus pentosus. The highest resistance rates were to ampicillin and streptomycin. The highest susceptibility rates were shown to tetracycline, chloramphenicol and penicillin G. None of the strains showed multidrug resistance. Resistance rates by DD and MIC were not different (P>0.05 for ampicillin, chloramphenicol, erythromycin and penicillin G. Future research should assess the genetic mechanisms underlying the phenotypic resistance in Lactobacillus strains to screen the potential probiotic strains for the development of functional meat products.

Differential resistances to anthracnose in Capsicum baccatum as responding to two Colletotrichum pathotypes and inoculation methods.

Science.gov (United States)

Mahasuk, Pitchayapa; Chinthaisong, Jittima; Mongkolporn, Orarat

2013-09-01

Chili anthracnose, caused by Colletotrichum spp., is one of the major diseases to chili production in the tropics and subtropics worldwide. Breeding for durable anthracnose resistance requires a good understanding of the resistance mechanisms to different pathotypes and inoculation methods. This study aimed to investigate the inheritances of differential resistances as responding to two different Colletotrichum pathotypes, PCa2 and PCa3 and as by two different inoculation methods, microinjection (MI) and high pressure spray (HP). Detached ripe fruit of Capsicum baccatum 'PBC80' derived F2 and BC1s populations was assessed for anthracnose resistance. Two dominant genes were identified responsible for the differential resistance to anthracnose. One was responsible for the resistance to PCa2 and PCa3 by MI and the other was responsible for the resistance to PCa3 by HP. The two genes were linked with 16.7 cM distance.

Review of state of the art methods for measuring water in landfills

International Nuclear Information System (INIS)

Imhoff, Paul T.; Reinhart, Debra R.; Englund, Marja; Guerin, Roger; Gawande, Nitin; Han, Byunghyun; Jonnalagadda, Sreeram; Townsend, Timothy G.; Yazdani, Ramin

2007-01-01

In recent years several types of sensors and measurement techniques have been developed for measuring the moisture content, water saturation, or the volumetric water content of landfilled wastes. In this work, we review several of the most promising techniques. The basic principles behind each technique are discussed and field applications of the techniques are presented, including cost estimates. For several sensors, previously unpublished data are given. Neutron probes, electrical resistivity (impedance) sensors, time domain reflectometry (TDR) sensors, and the partitioning gas tracer technique (PGTT) were field tested with results compared to gravimetric measurements or estimates of the volumetric water content or moisture content. Neutron probes were not able to accurately measure the volumetric water content, but could track changes in moisture conditions. Electrical resistivity and TDR sensors tended to provide biased estimates, with instrument-determined moisture contents larger than independent estimates. While the PGTT resulted in relatively accurate measurements, electrical resistivity and TDR sensors provide more rapid results and are better suited for tracking infiltration fronts. Fiber optic sensors and electrical resistivity tomography hold promise for measuring water distributions in situ, particularly during infiltration events, but have not been tested with independent measurements to quantify their accuracy. Additional work is recommended to advance the development of some of these instruments and to acquire an improved understanding of liquid movement in landfills by application of the most promising techniques in the field

Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

Science.gov (United States)

Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

2002-01-01

Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

Interpretation of hole-to-surface resistivity measurements at Yucca Mountain, Nevada Test Site

International Nuclear Information System (INIS)

Daniels, J.J.; Scott, J.H.

1981-01-01

Hole-to-surface resistivity measurements at Yucca Mountain indicate the presence of many near-surface geologic inhomogeneities, with no definite indication of deep structural features. A resistive anomaly near drill hole UE25a-6 is interpreted as a thin, vertical, resistive body that nearly intersects the surface, and may be caused by a silicified, or calcified, fracture zone. A resistive anomaly near hole UE25a-7 is probably caused by a near surface, horizontal, lens-shaped body that may represent a devitrified zone in the Tiva Canyon Member. Many conductive anomalies were detected to the southwest of hole UE25a-4. However, these anomalies are interpreted to be caused by variations in the thickness of the surface alluvium

Polarization and resistivity measurements of post-crystallization changes in amorphous Fe-B-Si alloys

International Nuclear Information System (INIS)

Chattoraj, I.; Bhattamishra, A.K.; Mitra, A.

1993-01-01

The effects of grain growth and compositional changes on the electrochemical behavior and the resistivity of amorphous iron-boron-silicon (Fe 77.5 B 15 Si 7.5 ) alloys after crystallization were studied. Deterioration of the protective passive film was observed, along with increased annealing. Potentiodynamic polarization provided excellent information about microstructural and chemical changes. It was concluded that electrochemical measurements could be used in conjunction with resistivity measurements in direct studies of grain growth and chemical changes occurring in different phases of the devitrified alloy

Accurate calibration of resistance ratios between 1 MΩ and 1 GΩ using series resistors

International Nuclear Information System (INIS)

Yu, Kwang Min; Ihm, G

2011-01-01

As shown in high-resistance key comparisons carried out by the Consultative Committee for Electricity and Magnetism (CCEM), Inter-American Metrology System (SIM) and European Association of National Metrology Institutes (EURAMET), the accuracy of 10 MΩ and 1 GΩ resistances depends on ratio values between the reference resistance and unknown resistance and the accuracy of the reference resistance, which is determined with a quantized Hall resistance standard. This paper presents a method for calibrating 10:1 ratios in a high-resistance bridge using series resistors simply and accurately. By applying the 10:1 ratio errors determined using the presented method, the combined relative standard uncertainty for 1 GΩ resistance measurements using a modified Wheatstone bridge was estimated to be on the 1 × 10 −6 level. The method was also applied to 1 GΩ resistance measurements using a direct-current comparator resistance bridge. It was found that the 1 GΩ resistances determined by the two bridges agreed within 2.4 × 10 −6 Ω/Ω. We expect that the presented method can also be used to calibrate arbitrary resistance ratios

Development of test method for evaluating root resistance of pavement used for roof garden caused by thickening growth of root

Energy Technology Data Exchange (ETDEWEB)

Ishihara, Saori; Tanaka, Kyoji [Tokyo Institute of Technology, Tokyo, (Japan)

2010-07-01

The growth of roots of plants can damage roof garden components, such as pavements. This paper developed a test method for evaluating the resistance of pavement used in roof gardens to damage from a thickening growth of roots. The study assessed the behaviour of plant roots and evaluated the force of root growth subjected to hypertrophy. A system to measure the enlargement force of roots was designed and used for measurements over a period of 8 months on a cherry blossom of 21 years growth. The enlargement force was approximately 440 N/cm. A mechanical simulated root was designed and used to carry out experimental tests on asphalt pavements. The tests results demonstrated the viability of simulated root for evaluation of root resistances in pavements and various components of roof gardens.

Electrical Resistivity Measurements of Downscaled Homogenous ...

African Journals Online (AJOL)

Knowledge of electrical resistivity for reservoir rocks is crucial for a number of reservoir engineering tasks such as the determination of oil-in-place and the calibration of resistivity logs. Those properties can now be predicted by numerical calculations directly on micro-CT images taken from rock fragments typically having a ...

How to measure the impacts of antibiotic resistance and antibiotic development on empiric therapy: new composite indices.

Science.gov (United States)

Hughes, Josie S; Hurford, Amy; Finley, Rita L; Patrick, David M; Wu, Jianhong; Morris, Andrew M

2016-12-16

We aimed to construct widely useable summary measures of the net impact of antibiotic resistance on empiric therapy. Summary measures are needed to communicate the importance of resistance, plan and evaluate interventions, and direct policy and investment. As an example, we retrospectively summarised the 2011 cumulative antibiogram from a Toronto academic intensive care unit. We developed two complementary indices to summarise the clinical impact of antibiotic resistance and drug availability on empiric therapy. The Empiric Coverage Index (ECI) measures susceptibility of common bacterial infections to available empiric antibiotics as a percentage. The Empiric Options Index (EOI) varies from 0 to 'the number of treatment options available', and measures the empiric value of the current stock of antibiotics as a depletable resource. The indices account for drug availability and the relative clinical importance of pathogens. We demonstrate meaning and use by examining the potential impact of new drugs and threatening bacterial strains. In our intensive care unit coverage of device-associated infections measured by the ECI remains high (98%), but 37-44% of treatment potential measured by the EOI has been lost. Without reserved drugs, the ECI is 86-88%. New cephalosporin/β-lactamase inhibitor combinations could increase the EOI, but no single drug can compensate for losses. Increasing methicillin-resistant Staphylococcus aureus (MRSA) prevalence would have little overall impact (ECI=98%, EOI=4.8-5.2) because many Gram-positives are already resistant to β-lactams. Aminoglycoside resistance, however, could have substantial clinical impact because they are among the few drugs that provide coverage of Gram-negative infections (ECI=97%, EOI=3.8-4.5). Our proposed indices summarise the local impact of antibiotic resistance on empiric coverage (ECI) and available empiric treatment options (EOI) using readily available data. Policymakers and drug developers can use the

Direct measurement of graphene contact resistivity to pre-deposited metal in buried contact test structure

KAUST Repository

Qaisi, Ramy M.; Smith, Casey; Ghoneim, Mohamed T.; Yu, Qingkai; Hussain, Muhammad Mustafa

2013-01-01

We demonstrate a buried contact based novel test structure for direct contact resistivity measurement of graphene-metal interfaces. We also observe excellent contact resistivity 1 μO-cm2 without any additional surface modification suggesting that the intrinsic Au-graphene contact is sufficient for achieving devices with low contact resistance. The chemical mechanical polishing less test structure and data described herein highlights an ideal methodology for systematic screening and engineering of graphene-metal contact resistivity to enable low power high speed carbon electronics. © 2013 IEEE.

Direct measurement of graphene contact resistivity to pre-deposited metal in buried contact test structure

KAUST Repository

Qaisi, Ramy M.

2013-08-01

We demonstrate a buried contact based novel test structure for direct contact resistivity measurement of graphene-metal interfaces. We also observe excellent contact resistivity 1 μO-cm2 without any additional surface modification suggesting that the intrinsic Au-graphene contact is sufficient for achieving devices with low contact resistance. The chemical mechanical polishing less test structure and data described herein highlights an ideal methodology for systematic screening and engineering of graphene-metal contact resistivity to enable low power high speed carbon electronics. © 2013 IEEE.

Improvement of methods to evaluate brittle failure resistance of the WWER reactor pressure vessels

Energy Technology Data Exchange (ETDEWEB)

Popov, A A; Parshutin, E V [Engineering Center of Nuclear Equipment Strength, Research and Development Inst. of Power Engineering, Moscow (Russian Federation); Rogov, M F; Dragunov, U G [Experimenter` s and Designer` s Office ` ` Hydropress` ` (Russian Federation)

1997-09-01

At the next 10 years a number of Russian WWER nuclear power plants will complete its design lifetime. Normative methods to evaluate brittle failure resistance of the reactor pressure vessels used in Russia have been intended for design stage. The evaluation of reactor pressure vessel lifetime in operation stage demands to create new methods of calculation and new methods for experimental evaluation of brittle failure resistance degradation. The main objective of the study in this type of reactor is weldment number 4. In this report an analysis is made of methods to determine critical temperature of reactor materials including the results of instrumented Charpy testing. 12 figs.

Surveillance of drug resistance for tuberculosis control: why and how?

Science.gov (United States)

Chaulet, P; Boulahbal, F; Grosset, J

1995-12-01

The resistance of Mycobacterium tuberculosis to antibiotics, which reflects the quality of the chemotherapy applied in the community, is one of the elements of epidemiological surveillance used in national tuberculosis programmes. Measurement of drug resistance poses problems for biologists in standardization of laboratory methods and quality control. The definition of rates of acquired and primary drug resistance also necessitates standardization in the methods used to collect information transmitted by clinicians. Finally, the significance of the rates calculated depends on the choice of the patients sample on which sensitivity tests have been performed. National surveys of drug resistance therefore require multidisciplinary participation in order to select the only useful indicators: rates of primary resistance and of acquired resistance. These indicators, gathered in representative groups of patients over a long period, are a measurement of the impact of modern chemotherapy regimens on bacterial ecology.

Laboratory, greenhouse and field methods for screening rust-resistant wheat cultivars

International Nuclear Information System (INIS)

Mashaal, S.F.; Kiraly, Z.; Barabas, Z.; Barna, B.; Cereal Research Inst., Szeged, Hungary)

1977-01-01

Detached flag leaf cultures were not suitable for evaluation of stem-rust resistance in our screening programme. On the basis of yield evaluation it was possible to screen out ten stem-rust ''tolerant'' wheat lines in field experiments. Rusted and protected microplots of each line were paired within a replicate. After artificial inoculation, the protected plants were sprayed with fungicides (benomyl plus dithiocarbamate plus copper salt) at weekly intervals until maturation to keep each protected plot rust-free. The thousand-kernel weights of rusted and protected plots were compared. When the thousand-kernel weight of protected plot increased only slightly and the rust reaction type of plants was susceptible in the rusted plot, the line was screened out as putative ''tolerant''. On the basis of three-year field trial ten ''tolerant'' lines were selected. Nine out of ten lines proved to be resistant to two stem-rust races in greenhouse tests in the seedling stage, when resistance was determined on the basis of reduced spore production instead of infection types. Resistance of these seedlings related partly to the reduced number of pustules and partly to a slow rusting character of plants. It seems possible to screen resistant cultivars in the greenhouse by the method outlined in this paper, when resistance is determined on the basis of a reduced number of infection sites and/or by the slow rusting capacity. (author)

Mechanisms of methicillin resistance in Staphylococcus aureus and methods for laboratory detection.

Science.gov (United States)

Jorgensen, J H

1991-01-01

Three distinctly different mechanisms of methicillin resistance have been described in Staphylococcus aureus. The best-documented and probably most important mechanism is production of a unique, low affinity penicillin-binding protein, PBP 2a. Strains possessing PBP 2a are resistant to methicillin, oxacillin, and probably all other currently available beta-lactam antibiotics. Two additional mechanisms of reduced susceptibility to methicillin have been described. Borderline resistance (BORSA) to the semi-synthetic penicillins has been attributed to the hyperproduction of normal staphylococcal beta-lactamase. A third mechanism has recently been advanced that describes an intermediate level of resistance to methicillin due to production of modified, normal PBPs with reduced affinity for beta-lactams (MODSA). Little is known regarding the prevalence or clinical significance of the BORSA and MODSA strains. The most reliable in vitro susceptibility test methods for detecting MRSA (strains possessing PBP 2a) include the microdilution minimum inhibitory concentration (MIC) test (with 2% NaCl supplemented broth), the oxacillin agar screen plate test (incorporating 6 micrograms/ml oxacillin in 4% NaCl supplemented agar), and the National Committee for Clinical Laboratory Standards (NCCLS) disk diffusion test with oxacillin. All three methods use direct inoculum preparation and incubation of tests at 35 degrees C for a full 24 hours.

Application of the electrostatic Thompson–Lampard theorem to resistivity measurements

Czech Academy of Sciences Publication Activity Database

Mareš, Jiří J.; Hubík, Pavel; Krištofik, Jozef

2012-01-01

Roč. 23, č. 4 (2012), s. 1-5 ISSN 0957-0233 R&D Projects: GA ČR GAP204/10/0212 Institutional research plan: CEZ:AV0Z10100521 Keywords : resistivity * Thompson–Lampard theorem * van der Pauw method Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.435, year: 2012

A novel voltage clamp circuit for the measurement of transistor dynamic on-resistance

NARCIS (Netherlands)

Gelagaev, R.; Jacqmaer, P.; Everts, J.; Driesen, Johan

2012-01-01

For determining the dynamic on-resistance Rdyn,on of a power transistor, the voltage and current waveforms have to be measured during the switching operation. In measurements of voltage waveforms, using an oscilloscope, the characteristics of an amplifier inside the oscilloscope are distorted when

Direct measurement of resistance of multiwalled carbon nanotubes using micro four-point probes

DEFF Research Database (Denmark)

Dohn, Søren; Mølhave, Kristian; Bøggild, Peter

2005-01-01

-point resistance at specific positions along the nanotubes, was measured by microprobes with different microelectrocle spacings. Individual nanotubes were investigated in more detail by measuring current as a function of bias voltage until the point of failure and the results are compared to previously reported...

Inter-strand resistance measurements in the termination of the ITER SULTAN samples

International Nuclear Information System (INIS)

Cau, F; Bruzzone, P

2009-01-01

In cabled conductors a perfect uniformity of the current among the strands is hardly reached, due to the non-homogeneity of the contact resistance distribution between the strands and the copper of the electrical terminations. In the case of large current unbalance, the overloaded strands hit the critical surface at high field early, developing a current sharing voltage, which drives the redistribution of the current, mainly in the electrical terminations where the inter-strand resistance is lower than in the high field conductor. If the inter-strand resistance in the termination is low, the voltage levels are sufficiently low to allow an effective redistribution of the current to the less loaded strands. The inter-strand resistance of three different termination layouts of ITER short length samples is measured to make a database available which can be used to qualify the layout of the joints and their capability of redistributing the current among the strands.

Introduction to tensorial resistivity probability tomography

OpenAIRE

Mauriello, Paolo; Patella, Domenico

2005-01-01

The probability tomography approach developed for the scalar resistivity method is here extended to the 2D tensorial apparent resistivity acquisition mode. The rotational invariant derived from the trace of the apparent resistivity tensor is considered, since it gives on the datum plane anomalies confined above the buried objects. Firstly, a departure function is introduced as the difference between the tensorial invariant measured over the real structure and that computed for a reference uni...

Characterization of Multidrug Resistant E. faecalis Strains from Pigs of Local Origin by ADSRRS-Fingerprinting and MALDI -TOF MS; Evaluation of the Compatibility of Methods Employed for Multidrug Resistance Analysis.

Directory of Open Access Journals (Sweden)

Aneta Nowakiewicz

Full Text Available The aim of this study was to characterize multidrug resistant E. faecalis strains from pigs of local origin and to analyse the relationship between resistance and genotypic and proteomic profiles by amplification of DNA fragments surrounding rare restriction sites (ADSRRS-fingerprinting and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI -TOF MS. From the total pool of Enterococcus spp. isolated from 90 pigs, we selected 36 multidrug resistant E. faecalis strains, which represented three different phenotypic resistance profiles. Phenotypic resistance to tetracycline, macrolides, phenicols, and lincomycin and high-level resistance to aminoglycosides were confirmed by the occurrence of at least one corresponding resistance gene in each strain. Based on the analysis of the genotypic and phenotypic resistance of the strains tested, five distinct resistance profiles were generated. As a complement of this analysis, profiles of virulence genes were determined and these profiles corresponded to the phenotypic resistance profiles. The demonstration of resistance to a wide panel of antimicrobials by the strains tested in this study indicates the need of typing to determine the spread of resistance also at the local level. It seems that in the case of E. faecalis, type and scope of resistance strongly determines the genotypic pattern obtained with the ADSRRS-fingerprinting method. The ADSRRS-fingerprinting analysis showed consistency of the genetic profiles with the resistance profiles, while analysis of data with the use of the MALDI- TOF MS method did not demonstrate direct reproduction of the clustering pattern obtained with this method. Our observations were confirmed by statistical analysis (Simpson's index of diversity, Rand and Wallace coefficients. Even though the MALDI -TOF MS method showed slightly higher discrimination power than ADSRRS-fingerprinting, only the latter method allowed reproduction of the

Application of two electrical methods for the rapid assessment of freezing resistance in Salix epichloro

Energy Technology Data Exchange (ETDEWEB)

Tsarouhas, V.; Kenney, W.A.; Zsuffa, L. [University of Toronto, Ontario (Canada). Faculty of Forestry

2000-09-01

The importance of early selection of frost-resistant Salix clones makes it desirable to select a rapid and accurate screening method for assessing freezing resistance among several genotypes. Two electrical methods, stem electrical impedance to 1 and 10 khz alternating current, and electrolyte leakage of leaf tissue, were evaluated for detecting freezing resistance on three North America Salix epichloro Michx., clones after subjecting them to five different freezing temperatures (-1, -2, -3, -4, and -5 deg C). Differences in the electrical impedance to 1 and 10 kHz, and the ratio of the impedance at the two frequencies (low/high) before and after the freezing treatment (DZ{sub low}, DZ{sub high}, and DZ{sub ratio}, respectively) were estimated. Electrolyte leakage was expressed as relative conductivity (RC{sub t}) and index of injury (IDX{sub t}). Results from the two methods, obtained two days after the freezing stress, showed that both electrical methods were able to detect freezing injury in S. eriocephala. However, the electrolyte leakage method detected injury in more levels of freezing stress (-3, -4, and -5 deg C) than the impedance (-4, and -5 deg C), it assessed clonal differences in S. eriocephala freezing resistance, and it was best suited to correlate electrical methods with the visual assessed freezing injury. No significant impedance or leakage changes were found after the -1 and -2 deg C freezing temperatures. (author)

CT-scan-monitored electrical-resistivity measurements show problems achieving homogeneous saturation

International Nuclear Information System (INIS)

Sprunt, E.S.; Davis, R.M.; Muegge, E.L.; Desai, K.P.

1991-01-01

This paper reports on x-ray computerized tomography (CT) scans obtained during measurement of the electrical resistivity of core samples which revealed some problems in obtaining uniform saturation along the lengths of the samples. The electrical resistivity of core samples is measured as a function of water saturation to determine the saturation exponent used in electric-log interpretation. An assumption in such tests is that the water saturation is uniformly distributed. Failure of this assumption can result in errors in the determination of the saturation exponent. Three problems were identified in obtaining homogeneous water saturation in two samples of a Middle Eastern carbonate grainstone: a stationary front formed in one sample at 1-psi oil/brine capillary pressure, a moving front formed at oil/brine capillary pressure ≤4 psi in samples tested in fresh mixed-wettability and cleaned water-wet states, and the heterogeneous fluid distribution caused by a rapidly moving front did not dissipate when the capillary pressure was eliminated in the samples

The effect of metallization contact resistance on the measurement of the field effect mobility of long-channel unannealed amorphous In–Zn–O thin film transistors

International Nuclear Information System (INIS)

Lee, Sunghwan; Park, Hongsik; Paine, David C.

2012-01-01

The effect of contact resistance on the measurement of the field effect mobility of compositionally homogeneous channel indium zinc oxide (IZO)/IZO metallization thin film transistors (TFTs) is reported. The TFTs studied in this work operate in depletion mode as n-channel field effect devices with a field effect mobility calculated in the linear regime (μ FE ) of 20 ± 1.9 cm 2 /Vs and similar of 18 ± 1.3 cm 2 /Vs when calculated in the saturation regime (μ FE sat ). These values, however, significantly underestimate the channel mobility since a large part of the applied drain voltage is dropped across the source/drain contact interface. The transmission line method was employed to characterize the contact resistance and it was found that the conducting-IZO/semiconducting-IZO channel contact is highly resistive (specific contact resistance, ρ C > 100 Ωcm 2 ) and, further, this contact resistance is modulated with applied gate voltage. Accounting for the contact resistance (which is large and modulated by gate voltage), the corrected μ FE is shown to be 39 ± 2.6 cm 2 /Vs which is consistent with Hall mobility measurements of high carrier density IZO.

Further elucidation of nanofluid thermal conductivity measurement using a transient hot-wire method apparatus

Science.gov (United States)

Yoo, Donghoon; Lee, Joohyun; Lee, Byeongchan; Kwon, Suyong; Koo, Junemo

2018-02-01

The Transient Hot-Wire Method (THWM) was developed to measure the absolute thermal conductivity of gases, liquids, melts, and solids with low uncertainty. The majority of nanofluid researchers used THWM to measure the thermal conductivity of test fluids. Several reasons have been suggested for the discrepancies in these types of measurements, including nanofluid generation, nanofluid stability, and measurement challenges. The details of the transient hot-wire method such as the test cell size, the temperature coefficient of resistance (TCR) and the sampling number are further investigated to improve the accuracy and consistency of the measurements of different researchers. It was observed that smaller test apparatuses were better because they can delay the onset of natural convection. TCR values of a coated platinum wire were measured and statistically analyzed to reduce the uncertainty in thermal conductivity measurements. For validation, ethylene glycol (EG) and water thermal conductivity were measured and analyzed in the temperature range between 280 and 310 K. Furthermore, a detailed statistical analysis was conducted for such measurements, and the results confirmed the minimum number of samples required to achieve the desired resolution and precision of the measurements. It is further proposed that researchers fully report the information related to their measurements to validate the measurements and to avoid future inconsistent nanofluid data.

Sampling and Pooling Methods for Capturing Herd Level Antibiotic Resistance in Swine Feces using qPCR and CFU Approaches

DEFF Research Database (Denmark)

Schmidt, Gunilla Veslemøy; Mellerup, Anders; Christiansen, Lasse Engbo

2015-01-01

The aim of this article was to define the sampling level and method combination that captures antibiotic resistance at pig herd level utilizing qPCR antibiotic resistance gene quantification and culture-based quantification of antibiotic resistant coliform indicator bacteria. Fourteen qPCR assays...... for commonly detected antibiotic resistance genes were developed, and used to quantify antibiotic resistance genes in total DNA from swine fecal samples that were obtained using different sampling and pooling methods. In parallel, the number of antibiotic resistant coliform indicator bacteria was determined...... when comparing individual sampling and pooling methods. qPCR on pooled samples was found to be a good representative for the general resistance level in a pig herd compared to the coliform CFU counts. It had significantly reduced relative standard deviations compared to coliform CFU counts in the same...

Method for increasing the resistance of a plant or a part thereof to a pathogen, method for screening the resistance of a plant or part thereof to a pathogen, and use thereof

OpenAIRE

Wit, de, P.; Stergiopoulos, I.; Kema, G.H.J.

2011-01-01

(EN)The present invention relates to the field of plant biotechnology. More in particular, the present invention relates to methods for increasing the resistance of a plant or part thereof that is susceptible to infection with a pathogen comprising an ortholog of the Avr4 protein of Cladosporium fulvum, wherein said plant is not a tomato or tobacco plant. The invention also relates to methods for screening the resistance of a plant or a part thereof to at least one pathogen, wherein said path...

A simple phenotypic method for screening of MCR-1-mediated colistin resistance.

Science.gov (United States)

Coppi, M; Cannatelli, A; Antonelli, A; Baccani, I; Di Pilato, V; Sennati, S; Giani, T; Rossolini, G M

2018-02-01

To evaluate a novel method, the colistin-MAC test, for phenotypic screening of acquired colistin resistance mediated by transferable mcr-1 resistance determinants, based on colistin MIC reduction in the presence of dipicolinic acid (DPA). The colistin-MAC test consists in a broth microdilution method, in which colistin MIC is tested in the absence or presence of DPA (900 μg/mL). Overall, 74 colistin-resistant strains of Enterobacteriaceae (65 Escherichia coli and nine other species), including 61 strains carrying mcr-1-like genes and 13 strains negative for mcr genes, were evaluated with the colistin-MAC test. The presence of mcr-1-like and mcr-2-like genes was assessed by real-time PCR and end-point PCR. For 20 strains, whole-genome sequencing data were also available. A ≥8-fold reduction of colistin MIC in the presence of DPA was observed with 59 mcr-1-positive strains, including 53 E. coli of clinical origin, three E. coli transconjugants carrying MCR-1-encoding plasmids, one Enterobacter cloacae complex and two Citrobacter spp. Colistin MICs were unchanged, increased or at most reduced by twofold with the 13 mcr-negative colistin-resistant strains (nine E. coli and four Klebsiella pneumoniae), but also with two mcr-1-like-positive K. pneumoniae strains. The colistin-MAC test could be a simple phenotypic test for presumptive identification of mcr-1-positive strains among isolates of colistin-resistant E. coli, based on a ≥8-fold reduction of colistin MIC in the presence of DPA. Evaluation of the test with a larger number of strains, species and mcr-type resistance determinants would be of interest. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Electromagnetic survey (TEM method) in Teradomari and examination of resistivity structure to be based on near surface information; Niigataken Teradomarimachi ni okeru denji tansa kekka (TEM ho) no doshitsu joho ni yoru kento

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, H; Mitsuhata, Y; Matsuo, K; Tanaka, H [Japan National Oil Corp., Tokyo (Japan). Technology Research Center; Wada, K [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan)

1996-10-01

TEM method was applied to estimate soil structure from resistivity change of underground water saturated stratum featured by slow S wave and fast P wave over 1500m/s. Vertical magnetic field was measured by underlaying a transmission loop of 60m{times}60m around a measuring point in Teradomari, Niigata prefecture, and by installing a magnetic sensor at the measuring point. From comparison of a soil profile with the resistivity profile obtained by TEM data, the former well consisted with the latter. The surface low resistivity stratum corresponded to alluvium from comparison of it with soil and logging data. This alluvium base with fast P wave over 1500m/s satisfied the condition of optimum blasting depth because of a saturated stratum in the surface base. The resistivity structure was related to a saturated stratum. Sand bed was thick at the interface between alluvium low ground and hill area, and from the analytical result, the depth of sand bed showing high resistivity was more shallow than that of the alluvium base, pointing out necessary notice in interpretation. Resistivity survey is promising as simple method for optimum blasting depth. 4 refs., 6 figs., 1 tab.

Joint resistance measurements of pancake and terminal joints for JT-60SA EF coils

Energy Technology Data Exchange (ETDEWEB)

Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Murakami, Haruyuki; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

2013-11-15

Highlights: • To evaluate the joint fabrication technology for the JT-60SA EF coils, joint resistance measurements were conducted with a joint sample. • The joint sample was composed of pancake and terminal joints. • The measurements demonstrated that both joints fulfilled the design requirement. • Considering the measurements, the characteristics of both joints were investigated using an analytical model that represents the joints. -- Abstract: To evaluate the joint fabrication technology for the JT-60SA EF coils, joint resistance measurements were conducted using a sample consisting of pancake and terminal joints. Both joints are shake-hands lap joints composed of cable-in-conduit conductors and a pure copper saddle-shaped spacer. The measurements demonstrated that both joints fulfilled the design requirement. Considering these measurements, the characteristics of both joints were investigated using analytical models that represent the joints. The analyses indicated that the characteristics of the conductors used in the joints affect the characteristics of the joints.

Calorimetric method for current sharing temperature measurements in ITER conductor samples in SULTAN

International Nuclear Information System (INIS)

Bagnasco, M.

2009-01-01

Several Toroidal Field Conductor short samples with slight layout variations have been assembled and tested in the SULTAN facility at CRPP. The measurement campaigns started in 2007 and are still ongoing. The performance of every conductor is expressed in terms of current sharing temperature (T cs ), i.e. the temperature at which a defined electric field, 10 μV/m, is detected in the cable due to the incipient superconducting-to-normal state transition. The T cs at specific operating conditions is the key design parameter for the ITER conductors and is the main object of the qualification tests. Typically, the average electric field is measured with voltage tap pairs attached on the jacket along the conductor. The inability however to explain observed premature voltage developments opened the discussion about possible alternative measuring methods. The He flow calorimetric method is based on the measurement of the resistive power generation in the conductor. It relies on the detection of very small temperature increases along the conductor in steady state operation. The accuracy and the reliability of the calorimetric method in SULTAN are critically discussed, with particular emphasis on the instrumentation requirements and test procedures. The application of the calorimetric method to the recent SULTAN test campaigns is described with its merits and limits. For future tests of ITER conductors in SULTAN, the calorimetric method for T cs test is proposed as a routine procedure.

Construction and in vitro test of a new electrode for dentin resistance measurement.

Science.gov (United States)

Stein, Steffen; Gente, Michael

2013-10-01

It is necessary to reduce the tooth substance before treating a tooth with a dental crown. The preparation often requires reduction of the dentin. This results in a dentin wound and a thinner substance over the pulp, increases the risk of inflammation, and could result in necrosis of the pulp. To give the dentist information about the amount of dentin over the pulp during preparation, the Prepometer was developed. The function of this device is based on the measurement of the electric resistance of the tooth substance. The measuring behavior of the first-generation Prepometer is characterized by smaller values of electric resistance before reaching full contact of the measuring head to the dentin surface and the actual value RT. This measuring behavior can mislead inexperienced therapists with inaccurate values that suggest thinner dentin than the reality. In this study, a new electrode based on the technology of active guard drive was constructed to overcome this issue. The results show that improvement in the measuring behavior of the new electrode could be achieved, eliminating the earlier disadvantage of the Prepometer.

Automated methods of corrosion measurement

DEFF Research Database (Denmark)

Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

1997-01-01

to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...... is applied to nearly all types of measurements today....

Measurement and Correlation of Indices of Insulin Resistance in Patients on Peritoneal Dialysis.

Science.gov (United States)

King-Morris, Kelli R; Deger, Serpil Muge; Hung, Adriana M; Egbert, Phyllis Ann; Ellis, Charles D; Graves, Amy; Shintani, Ayumi; Ikizler, T Alp

2016-01-01

♦ Insulin resistance (IR) is common in maintenance dialysis patients and is associated with excess mortality. Hyperinsulinemic euglycemic glucose clamp (HEGC) is the gold standard for measuring IR. There are limited studies using HEGC for comparison to other indirect indices of IR in peritoneal dialysis (PD) patients, nor have there been direct comparisons between patients receiving PD and those on maintenance hemodialysis (MHD) with regard to severity of IR, methods of measurement, or factors associated with the development of IR. ♦ This is a cross-sectional, single-center study performed in 10 prevalent PD patients of median age 48 years (range 41 - 54); 50% were female and 60% were African American. Insulin resistance was assessed by HEGC (glucose disposal rate [GDR]), homeostatic model assessment of IR (HOMA-IR), HOMA-IR corrected by adiponectin (HOMA-AD), leptin adiponectin ratio (LAR), quantitative insulin sensitivity check index (QUICKI), McAuley's index, and oral glucose tolerance test (OGTT) at each time point for a total of 18 studies. Retrospective analysis compared this cohort to 12 hemodialysis patients who had previously undergone similar testing. ♦ The median GDR was 6.4 mg/kg/min (interquartile range [IQR] 6.0, 7.8) in the PD cohort compared with the MHD group, which was 5.7 mg/kg/min (IQR 4.3, 6.6). For both the PD and MHD cohorts, the best predictors of GDR by HEGC after adjusting for age, gender, and body mass index (BMI), were HOMA-AD (PD: r = -0.69, p = 0.01; MHD: r = -0.78, p = 0.03) and LAR (PD: r = -0.68, p failed to have strong predictive value. Eight of 10 PD patients had at least 1 abnormal OGTT, demonstrating impaired glucose tolerance. ♦ Insulin resistance is highly prevalent in PD patients. The adipokine based formulas, HOMA-AD and LAR, correlated well in both the PD and MHD populations in predicting GDR by HEGC, outperforming HOMA-IR. The use of these novel markers could be considered for large-scale, epidemiological outcome

On-line monitoring of resistance of aqueous solutions at high temperature

International Nuclear Information System (INIS)

Hu Shilin; Zhang Pingzhu; Shang Weiguo

1999-01-01

The coulostatic measurement is a fast speed electrochemical test method. By this technology, analyzing Δ E(t)- T curves recorded under coulostatic perturbation, the solution resistance R l , resistance of coated film R f , capacity of coated film C f , Polarization resistance R p and double layer capacity C d are obtained. The resistance variety of 0.05N KCl is measured from room temperature up to 255 deg. C under saturation steam pressure. (author)

IMPROVING THE STABILITY OF TONAL TRACK CIRCUITS UNDER FLUCTUATIONS OF BALLAST RESISTANCE

Directory of Open Access Journals (Sweden)

K. V. Honcharov

2013-11-01

Full Text Available Purpose.The purpose of investigation is the development of method for improving the stability of tonal track circuits that takes into account the actual insulation resistance (ballast resistance of rail line.Methodology. To achieve the research purpose it was proposed to automatically determine the insulation resistance of rail line, and depending on this value to adjust the output voltage of track generator. Ballast resistance is determined by the value of input resistance the rail line, which at high frequencies practically is equal to the wave impedance. To implement the proposed method it is necessary to connect to the track circuit additional high-frequency generators, high-frequency filters, unit for finding the ballast resistance and adjusting the output voltage of track generator. Findings. As a result of research it was found that at low values (less than 2 Ohms*km the change of ballast resistance causes significant change of voltage at the track receiver input, which may cause malfunction of the track circuit. Increasing the length of rail line leads to the reducing of its input resistance, raising the measuring frequency causes increasing the input resistance. In both cases, the input resistance tends to the value of the wave impedance. The measuring frequency should be chosen taking into account the length of rail line and the upper limit of ballast resistance, the value 5 Ohms*km can be taken as that limit. At higher values of ballast resistance its changes insignificantly influence the input voltage of track receiver. In this case, the adaptive adjustment of voltage at the track generator output is not performed. Originality. The method for measuring the insulation resistance of rail line has been improved that allows one to determine the ballast resistance automatically. The dependence between measuring frequency, length of rail line and ballast resistance have been determined. Practical value. The proposed method allows one to

Cell shunt resistance and photovoltaic module performance

Energy Technology Data Exchange (ETDEWEB)

McMahon, T.J.; Basso, T.S.; Rummel, S.R. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, the authors verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. The authors discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.

Inter-filament resistance, effective transverse resistivity and coupling loss in superconducting multifilamentary NbTi and Nb3Sn strands

NARCIS (Netherlands)

Zhou, Chao; Dhalle, Marc M.J.; Nijhuis, Arend

2012-01-01

The effective transverse resistivity of a range of multi-filamentary Nb3Sn and NbTi strands is measured with a direct four-probe method and the data are compared to the transverse resistivity values obtained from AC coupling loss experiments. Correspondence between both is satisfactory provided that

PFA-100-measured aspirin resistance is the predominant risk factor for hospitalized cardiovascular events in aspirin-treated patients: A 5-year cohort study.

Science.gov (United States)

Chen, H Y; Chou, P

2018-04-01

Aspirin therapy is the clinical gold standard for the prevention of cardiovascular events. However, cardiovascular events still develop in some patients undergoing aspirin therapy. Many laboratory methods exist for measuring aspirin resistance. Using the platelet Function Analyzer (PFA)-100 system, we aimed to determine the effect of aspirin resistance on hospitalized cardiovascular events (hCVE) in a 5-year follow-up cohort. We also sought to determine the impact of aspirin resistance on the relationship between common cardiovascular risk factors and cardiovascular hospitalization. Aspirin resistance was evaluated in aspirin-treated patients from the outpatient department. A total of 465 patients during a 5-year follow-up period were included in this study. The primary endpoint of the study was hospitalization for any acute cardiovascular event. The prevalence and associated risk factors of acute cardiovascular events were evaluated. Aspirin resistance was prevalent in 91 (20.0%) of 465 patients. Prior hospitalization history of cardiovascular events was highly associated with aspirin resistance (P = .001). At the 5-year follow-up, cardiovascular events were found to have developed in 11 patients (8 stroke and 3 myocardial infarction) who exhibited aspirin resistance (12.1%) and in 9 (4 stroke and 5 myocardial infarction) patients who did not exhibit aspirin resistance (2.4%) (P resistance and cardiovascular events (adjusted odds ratio 4.28; 95% CI: 1.64-11.20; P = .03). PFA-100 measurements of aspirin resistance correlate with hCVE, as evidenced by both the past medical history and the 5-year follow-up. The logistic regression analysis results showed that aspirin resistance plays a larger role in hospitalized cardiovascular disease than do other cardiovascular risk factors. © 2017 John Wiley & Sons Ltd.

WGS accurately predicts antimicrobial resistance in Escherichia coli

Science.gov (United States)

Objectives: To determine the effectiveness of whole-genome sequencing (WGS) in identifying resistance genotypes of multidrug-resistant Escherichia coli (E. coli) and whether these correlate with observed phenotypes. Methods: Seventy-six E. coli strains were isolated from farm cattle and measured f...

Detecting and monitoring of water inrush in tunnels and coal mines using direct current resistivity method: A review

Directory of Open Access Journals (Sweden)

Shucai Li

2015-08-01

Full Text Available Detecting, real-time monitoring and early warning of underground water-bearing structures are critically important issues in prevention and mitigation of water inrush hazards in underground engineering. Direct current (DC resistivity method is a widely used method for routine detection, advanced detection and real-time monitoring of water-bearing structures, due to its high sensitivity to groundwater. In this study, the DC resistivity method applied to underground engineering is reviewed and discussed, including the observation mode, multiple inversions, and real-time monitoring. It is shown that a priori information constrained inversion is desirable to reduce the non-uniqueness of inversion, with which the accuracy of detection can be significantly improved. The focused resistivity method is prospective for advanced detection; with this method, the flanking interference can be reduced and the detection distance is increased subsequently. The time-lapse resistivity inversion method is suitable for the regions with continuous conductivity changes, and it can be used to monitor water inrush in those regions. Based on above-mentioned features of various methods in terms of benefits and limitations, we propose a three-dimensional (3D induced polarization method characterized with multi-electrode array, and introduce it into tunnels and mines combining with real-time monitoring with time-lapse inversion and cross-hole resistivity method. At last, the prospective applications of DC resistivity method are discussed as follows: (1 available advanced detection technology and instrument in tunnel excavated by tunnel boring machine (TBM, (2 high-resolution detection method in holes, (3 four-dimensional (4D monitoring technology for water inrush sources, and (4 estimation of water volume in water-bearing structures.

Stainless steel welding method with excellent nitric acid corrosion resistance

International Nuclear Information System (INIS)

Matsushita, Yukinobu; Inazumi, Toru; Hyakubo, Tamako; Masamura, Katsumi.

1996-01-01

The present invention concerns a welding method for a stainless steel used in a circumstance being in contact with a highly oxidizing nitric acid solution such as nuclear fuel reprocessing facilities, upon welding 316 type austenite steel containing Mo while giving excellent nitric acid resistance. A method of TIG welding using a filler metal having a composition of C, Si, Mn, P, S, Ni, Cr, Mo and Cu somewhat different from a stainless steel mother material in which C, Si, Mn, P, S, Ni, Cr and Mo are specified comprises a step of TIG-welding the surface of the mother material and a step of TIG-welding the rear face of the mother material, in which the welding conditions for the rear face of the mother material are such that the distance between the surface of the outermost welding metal layer on the side of the surface of the mother material and the bottom of the groove is not less than 5mm, and an amount of welding heat is made constant. As a result, even if the method is used in a circumstance being in contact with a highly corrosive solution such as nitric acid, corrosion resistance is not degraded. (N.H.)

Measurement of Resistive Wall Mode stability in rotating high beta plasmas

International Nuclear Information System (INIS)

Reimerdes, H.; Bialek, J.; Garofalo, A.M.; Navratil, G.A.; Chance, M.S.; Menard, J.E.; Okabayashi, M.; Takahashi, H.; Chu, M.S.; Gohil, P.; Jackson, G.L.; Jensen, T.H.; La Haye, R.J.; Scoville, J.T.; Strait, E.J.; Jayakumar, R.J.; Liu, Y.Q.

2005-01-01

Toroidal plasma rotation in the order of a few percent of the Alfven velocity can stabilize the resistive wall mode and extend the operating regime of tokamaks from the conventional, ideal MHD no-wall limit up to the ideal MHD ideal wall limit. The stabilizing effect has been measured passively by measuring the critical plasma rotation required for stability and actively by probing the plasma with externally applied resonant magnetic fields. These measurements are compared to predictions of rotational stabilization of the sound wave damping and of the kinetic damping model using the MARS code. (author)

Calibration of resistance factors for drilled shafts for the new FHWA design method.

Science.gov (United States)

2013-01-01

The Load and Resistance Factor Design (LRFD) calibration of deep foundation in Louisiana was first completed for driven piles (LTRC Final Report 449) in May 2009 and then for drilled shafts using 1999 FHWA design method (ONeill and Reese method) (...

Comparison of different methods for measuring the passive film thickness on metals

International Nuclear Information System (INIS)

Benoit, Marie; Bataillon, Christian; Gwinner, Benoit; Miserque, Frédéric; Orazem, Mark E.; Sánchez-Sánchez, Carlos M.; Tribollet, Bernard; Vivier, Vincent

2016-01-01

Highlights: • In situ EIS and ex situ XPS were used for the characterization of zirconium oxide films. • The film thicknesses can be obtained from the analysis of a single EIS diagram. • A convenient graphical method to extract film properties is proposed. - Abstract: In situ electrochemical impedance spectroscopy (EIS) and ex situ X-ray photoelectron spectroscopy (XPS) measurements on electrogenerated zirconium oxide films on zirconium (Zr/ZrO_2) were used to quantify the oxide film thickness and resistivity profiles through the oxide. The EIS analysis presented here takes advantage of the high-frequency domain at which the constant-phase element (CPE) behavior of the oxide film reverts to a capacitive response and the Cole-Cole representations of the complex capacitance to extract the high-frequency capacitance of the oxide film without reference to the nature of the time-constant distribution within the oxide film. The film thickness of the ZrO_2 samples measured from the high-frequency capacitance of EIS were in good agreement with the thickness obtained from XPS. Moreover, the EIS analysis presented is based on the use of the integral solution of the power law model, which allows to obtain in one single EIS experiment, both the film thickness and the resistivity profile in the ZrO_2 film. This work suggests a convenient graphical method to extract film properties and serves to validate a key assumption of the power-law model for interpretation of CPE parameters in terms of physical properties.

Spatial Variability of Soil Physical Properties Obtained with Laboratory Methods and Their Relation to Field Electrical Resistivity Measurements

Science.gov (United States)

Dathe, A.; Nemes, A.; Bloem, E.; Patterson, M.; Gimenez, D.; Angyal, A.; Koestel, J. K.; Jarvis, N.

2017-12-01

Soil spatial heterogeneity plays a critical role for describing water and solute transport processes in the unsaturated zone. Although we have a sound understanding of the physical properties underlying this heterogeneity (like macropores causing preferential water flow), their quantification in a spatial context is still a challenge. To improve existing knowledge and modelling approaches we established a field experiment on an agriculturally used silty clay loam (Stagnosol) in SE Norway. Centimeter to decimeter scale heterogeneities were investigated in the field using electrical resistivity tomography (ERT) in a quasi-3D and a real 3D approach. More than 100 undisturbed soil samples were taken in the 2x1x1 m3plot investigated with 3D ERT to determine soil water retention, saturated and unsaturated hydraulic conductivities and bulk density in the laboratory. A subset of these samples was scanned at the computer tomography (CT) facility at the Swedish University of Agricultural Sciences in Uppsala, Sweden, with special emphasis on characterizing macroporosity. Results show that the ERT measurements captured the spatial distribution of bulk densities and reflected soil water contents. However, ERT could not resolve the large variation observed in saturated hydraulic conductivities from the soil samples. Saturated hydraulic conductivity was clearly related to the macroporosity visible in the CT scans obtained from the respective soil cores. Hydraulic conductivities close to saturation mainly changed with depths in the soil profile and therefore with bulk density. In conclusion, to quantify the spatial heterogeneity of saturated hydraulic conductivities scanning methods with a resolution smaller than the size of macropores have to be used. This is feasible only when the information obtained from for example CT scans of soil cores would be upscaled in a meaningful way.

Electrical-conductivity measurements of leachates for the rapid assessment of wasteform corrosion resistance

International Nuclear Information System (INIS)

Sales, B.C.; Petek, M.; Boatner, L.A.

1982-01-01

Measurements of the electrical conductivity of leachate solutions as a function of time can be used as an efficient, informative means of evaluation and comparison in the development of nuclear waste forms and in the preliminary analysis of their corrosion resistance in distilled water. Three separate applications of this technique are described in this work. These are: (1) its use in the optimization of the corrosion resistance of a crystalline wasteform (monazite); (2) a study of the protective ability of the surface layer (gel layer) which forms on the nuclear waste glass Frit 21 + 20 wt % SRW in distilled water; and (3) making comparisons of the overall corrosion resistance of three different nuclear wasteforms (i.e., monazite, SYNROC, and borosilicate glass). A complete solution analysis of the borosilicate glass leachate and a straightforward analysis of the conductivity results agree to within +-20%. In the absence of a complete, time consuming solution analysis, conductivity measurements can be used to estimate reliably the total ionic concentration in the leachate to within a factor of 2

Comparison of direct inter-filament resistance measurement on Nb3Sn strands between University of Twente and ENEA

NARCIS (Netherlands)

Zhou, Chao; Dhalle, Marc M.J.; Nijhuis, Arend; Breschi, M.; Spina, T.; Della Corte, A.; Corato, V.

2013-01-01

Experimental results of interfilament resistance measurements obtained with different facilities are compared. Two internal tin Nb3Sn strand types are tested at the University of Twente (UT) and ENEA Frascati. The direct interfilament resistance is measured with a standard four-point voltage-current

Measurement of inter-strand contact resistance in epoxy impregnated Nb3Sn Rutherford cables

International Nuclear Information System (INIS)

Giorgio Ambrosio

2003-01-01

An apparatus for the measurement, under transverse pressure, of the inter-strand contact resistance in epoxy-impregnated Nb 3 Sn Rutherford cables has been recently assembled at Fermilab. Procedures have been developed to instrument and measure samples extracted from Nb 3 Sn coils. Samples were extracted from coils fabricated with the Wind-and-React and the React-and-Wind technology, both presently under development at Fermilab. A ceramic binder is used to improve the insulation and to simplify the fabrication of coils using the Wind-and-React technology. Synthetic oil is used to prevent sintering during the heat treatment of coils to be wound after reaction. In order to evaluate the effects of the ceramic binder and of the synthetic oil on the inter-strand resistance, measurements of samples extracted from coils were compared with measurements of cable stacks with varying characteristics. In this paper we describe the apparatus, the sample preparation, the measurement procedure, and the results of the first series of tests

Risk analysis and detection of thrombosis by measurement of electrical resistivity of blood.

Science.gov (United States)

Sapkota, Achyut; Asakura, Yuta; Maruyama, Osamu; Kosaka, Ryo; Yamane, Takashi; Takei, Masahiro

2013-01-01

Monitoring of thrombogenic process is very important in ventricular assistance devices (VADs) used as temporary or permanent measures in patients with advanced heart failure. Currently, there is a lack of a system which can perform a real-time monitoring of thrombogenic activity. Electrical signals vary according to the change in concentration of coagulation factors as well as the distribution of blood cells, and thus have potential to detect the thrombogenic process in an early stage. In the present work, we have made an assessment of an instrumentation system exploiting the electrical properties of blood. The experiments were conducted using bovine blood. Electrical resistance tomography with eight-electrode sensor was used to monitor the spatio-temporal change in electrical resistivity of blood in thrombogenic and non-thrombogenic condition. Under non-thrombogenic condition, the resistivity was uniform across the cross-section and average resistivity monotonically decreased with time before remaining almost flat. In contrary, under thrombogenic condition, there was non-uniform distribution across the cross-section, and average resistivity fluctuated with time.

A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing

Directory of Open Access Journals (Sweden)

Robert Vogel

2016-09-01

Full Text Available Background: Understanding the pathogenic role of extracellular vesicles (EVs in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantification of EVs has presented several challenges, predominantly due to the small size of vesicles such as exosomes and the availability of various technologies to measure nanosized particles, each technology having its own limitations. Materials and Methods: A standardized methodology to measure the concentration of extracellular vesicles (EVs has been developed and tested. The method is based on measuring the EV concentration as a function of a defined size range. Blood plasma EVs are isolated and purified using size exclusion columns (qEV and consecutively measured with tunable resistive pulse sensing (TRPS. Six independent research groups measured liposome and EV samples with the aim to evaluate the developed methodology. Each group measured identical samples using up to 5 nanopores with 3 repeat measurements per pore. Descriptive statistics and unsupervised multivariate data analysis with principal component analysis (PCA were used to evaluate reproducibility across the groups and to explore and visualise possible patterns and outliers in EV and liposome data sets. Results: PCA revealed good reproducibility within and between laboratories, with few minor outlying samples. Measured mean liposome (not filtered with qEV and EV (filtered with qEV concentrations had coefficients of variance of 23.9% and 52.5%, respectively. The increased variance of the EV concentration measurements could be attributed to the use of qEVs and the polydisperse nature of EVs. Conclusion: The results of this study demonstrate the feasibility of this standardized methodology to facilitate comparable and reproducible EV concentration measurements.

Sensitivity of resistive and Hall measurements to local inhomogeneities

DEFF Research Database (Denmark)

Koon, Daniel W.; Wang, Fei; Petersen, Dirch Hjorth

2013-01-01

We derive exact, analytic expressions for the sensitivity of resistive and Hall measurements to local inhomogeneities in a specimen's material properties in the combined linear limit of a weak perturbation over an infinitesimal area in a small magnetic field. We apply these expressions both to four-point...... probe measurements on an infinite plane and to symmetric, circular van der Pauw discs, obtaining functions consistent with published results. These new expressions speed up calculation of the sensitivity for a specimen of arbitrary shape to little more than the solution of two Laplace equation boundary......-value problems of the order of N3 calculations, rather than N2 problems of total order N5, and in a few cases produces an analytic expression for the sensitivity. These functions provide an intuitive, visual explanation of how, for example, measurements can predict the wrong carrier type in n-type ZnO....

Establishment of a nested-ASP-PCR method to determine the clarithromycin resistance of Helicobacter pylori.

Science.gov (United States)

Luo, Xiao-Feng; Jiao, Jian-Hua; Zhang, Wen-Yue; Pu, Han-Ming; Qu, Bao-Jin; Yang, Bing-Ya; Hou, Min; Ji, Min-Jun

2016-07-07

To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23SrRNA gene in Helicobacter pylori (H. pylori) by nested-allele specific primer-polymerase chain reaction (nested-ASP-PCR). The gastric tissue and saliva samples from 99 patients with positive results of the rapid urease test (RUT) were collected. The nested-ASP-PCR method was carried out with the external primers and inner allele-specific primers corresponding to the reference strain and clinical strains. Thirty gastric tissue and saliva samples were tested to determine the sensitivity of nested-ASP-PCR and ASP-PCR methods. Then, clarithromycin resistance was detected for 99 clinical samples by using different methods, including nested-ASP-PCR, bacterial culture and disk diffusion. The nested-ASP-PCR method was successfully established to test the resistance mutation points 2142, 2143 and 2144 of the 23SrRNA gene of H. pylori. Among 30 samples of gastric tissue and saliva, the H. pylori detection rate of nested-ASP-PCR was 90% and 83.33%, while the detection rate of ASP-PCR was just 63% and 56.67%. Especially in the saliva samples, nested-ASP-PCR showed much higher sensitivity in H. pylori detection and resistance mutation rates than ASP-PCR. In the 99 RUT-positive gastric tissue and saliva samples, the H. pylori-positive detection rate by nested-ASP-PCR was 87 (87.88%) and 67 (67.68%), in which there were 30 wild-type and 57 mutated strains in gastric tissue and 22 wild-type and 45 mutated strains in saliva. Genotype analysis showed that three-points mixed mutations were quite common, but different resistant strains were present in gastric mucosa and saliva. Compared to the high sensitivity shown by nested-ASP-PCR, the positive detection of bacterial culture with gastric tissue samples was 50 cases, in which only 26 drug-resistant strains were found through analyzing minimum inhibitory zone of clarithromycin. The nested-ASP-PCR assay showed higher detection sensitivity than ASP-PCR and

Analysis for the depth of underground resistivity structure by using MT method

International Nuclear Information System (INIS)

Matsuo, Koichi; Yokoi, Koichi; Negi, Tateyuki; Kasagi, Toshio; Takahashi, Takeharu; Teshima, Minoru

2005-03-01

The present document is to report the result of resistivity monitoring by using MT (Magnetotelluric) method near the site proposed for the Horonobe Underground Research Program at the Horonobe-cho, Hokkaido by the Japan Nuclear Cycle Development Institute. The stationary MT observation system, installed near the HDB-1 borehole on November 2002, was moved to a site at the Hokusei-en, 4 km west of the first site. This system is monitoring for the depth of underground resistivity. Observation data at the Hokusei-en from February 1st 2004 to January 31st 2005 was added to the investigation in 2004 fiscal year. But, data cannot be obtained from July 8th to November 11th of 2004 due to the disconnection trouble of the optical fiber cable for data transfer. The results were as follows; 1) Telluric and magnetic time series data measured by MT unit were transferred to a PC installed in an observation through optical fiber cable and processed and edited automatically. 2) The standard deviation of the apparent resistivity depends on range of frequency, 3% or less in the vicinity of the Schumann resonance frequency. The Standard deviation of data from 80 Hz to 0.56 Hz was less or 13%. But the standard deviation of low frequency data was more or 15%. 3) Amplitude of telluric and magnetic spectra below 1 Hz is coincident with Geomagnetic Activity K-index. Clear correlation was not admitted in resistivity and K-index. 4) Data quality was studied compared with weather data. Clear correlation was not admitted for windy day and rainy day. 5) Data was edited by the new criterion of K-index 1.3 or more, wind 6 m/s or less, precipitation 6 mm or less. As a result, the improvement of the data quality was admitted by 5 frequencies of 9 frequencies. Only one side of resistivity Rxy and Ryx was improved by 4 frequencies of the remainder. 6) In addition, data was edited by the new criterion of the coherence of the electric-magnetic amplitude. As a result, the improvement of the data quality

Effect of radiation resistance additives for insulation materials

International Nuclear Information System (INIS)

Yamamoto, Yasuaki; Yagyu, Hideki; Seguchi, Tadao.

1988-01-01

For the electric wires and cables used in radiation environment such as nuclear power stations and fuel reprocessing facilities, the properties of excellent radiation resistance are required. For these insulators and sheath materials, ethylene propylene rubber, polyethylene and other polymers have been used, but it cannot be said that they always have good radiation resistance. However, it has been well known that radiation resistance can be improved with small amount of additives, and heat resistance and burning retarding property as well as radiation resistance are given to the insulators of wires and cables for nuclear facilities by mixing various additives. In this research, the measuring method for quantitatively determining the effect of Anti-rad (radiation resistant additive) was examined. Through the measurement of gel fraction, radical formation and decomposed gas generation, the effect of Anti-rad protecting polymers from radiation deterioration was examined from the viewpoint of chemical reaction. The experimental method and the results are reported. The radiation energy for cutting C-H coupling is polymers is dispersed by Anti-rad, and the probability of cutting is lowered. Anti-rad catches and extinguishes radicals that start oxidation reaction. (K.I.)

Investigation of colistin sensitivity via three different methods in Acinetobacter baumannii isolates with multiple antibiotic resistance.

Science.gov (United States)

Sinirtaş, Melda; Akalin, Halis; Gedikoğlu, Suna

2009-09-01

In recent years there has been an increase in life-threatening infections caused by Acinetobacter baumannii with multiple antibiotic resistance, which has lead to the use of polymyxins, especially colistin, being reconsidered. The aim of this study was to investigate the colistin sensitivity of A. baumannii isolates with multiple antibiotic resistance via different methods, and to evaluate the disk diffusion method for colistin against multi-resistant Acinetobacter isolates, in comparison to the E-test and Phoenix system. The study was carried out on 100 strains of A. baumannii (colonization or infection) isolated from the microbiological samples of different patients followed in the clinics and intensive care units of Uludağ University Medical School between the years 2004 and 2005. Strains were identified and characterized for their antibiotic sensitivity by Phoenix system (Becton Dickinson, Sparks, MD, USA). In all studied A. baumannii strains, susceptibility to colistin was determined to be 100% with the disk diffusion, E-test, and broth microdilution methods. Results of the E-test and broth microdilution method, which are accepted as reference methods, were found to be 100% consistent with the results of the disk diffusion tests; no very major or major error was identified upon comparison of the tests. The sensitivity and the positive predictive value of the disk diffusion method were found to be 100%. Colistin resistance in A. baumannii was not detected in our region, and disk diffusion method results are in accordance with those of E-test and broth microdilution methods.

Development of nondestructive hybrid measuring method for three-dimensional residual stress distribution of thick welded joint. Hybrid measuring method of inherent strain method and neutron diffraction method