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1

High temperature measuring device  

DOEpatents

A temperature measuring device for very high design temperatures (to 2,000.degree. C.). The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensionally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

Tokarz, Richard D. (West Richland, WA)

1983-01-01

2

Temperature measuring device  

SciTech Connect

Systems and methods are described for a wireless instrumented silicon wafer that can measure temperatures at various points and transmit those temperature readings to an external receiver. The device has particular utility in the processing of semiconductor wafers, where it can be used to map thermal uniformity on hot plates, cold plates, spin bowl chucks, etc. without the inconvenience of wires or the inevitable thermal perturbations attendant with them.

Lauf, R.J.; Bible, D.W.; Sohns, C.W.

1999-10-19

3

High-temperature-measuring device  

DOEpatents

A temperature measuring device for very high design temperatures (to 2000/sup 0/C) is described. The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensonally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

Not Available

1981-01-27

4

Temperature measurements of semiconductor devices - a review  

Microsoft Academic Search

There are numerous methods for measuring the temperature of an operating semiconductor device. The methods can be broadly placed into three generic categories: electrical, optical, and physically contacting. The fundamentals underlying each of the categories are discussed, and a review of the variety of techniques within each category is given. Some of the advantages and disadvantages as well as the

David L. Blackburn

2004-01-01

5

Comparison of temperature measurement devices in post anesthesia patients.  

PubMed

A descriptive correlational study was used to evaluate the correlation/agreement of oral and axillary temperature measurements to patient core temperatures obtained in the OR. Data collectors recorded oral or axillary patient temperature from 752 patients on admission and discharge from the PACU. Results indicated that there was a moderate correlation between each of the current devices and core temperature, but no agreement between core temperature and either device. Recommendations were made to use just one device throughout the organization, or to use the device used on admission throughout the hospitalization. PMID:18226783

Washington, Georgita Tolbert; Matney, Joetta Lynn

2008-02-01

6

Miniature ingestible telemeter devices to measure deep-body temperature  

NASA Technical Reports Server (NTRS)

A telemetry device comprised of a pill-size ingestible transmitter developed to obtain deep body temperature measurements of a human is described. The device has particular utility in the medical field where deep body temperatures provide an indication of general health.

Pope, J. M.; Fryer, T. B. (inventors)

1976-01-01

7

Autocompensation Device for Ultralow Temperature Measurements.  

National Technical Information Service (NTIS)

A noise-protected meter for ultralow temperatures with a thermoresistor symmetrically connected to a low-noise preamplifier at the input and with a driftless digital lock-in detector at the output is described. The negative feedback circuit includes a mul...

N. L. Gorodishenin V. A. Evdokimov S. S. Katushenok Y. F. Kiselev A. N. Chernikov

1987-01-01

8

Silicon device performance measurements to support temperature range enhancement  

NASA Technical Reports Server (NTRS)

Silicon based power devices can be used at 200 C. The device measurements made during this program show a predictable shift in device parameters with increasing temperature. No catastrophic or abrupt changes occurred in the parameters over the temperature range. As expected, the most dramatic change was the increase in leakage currents with increasing temperature. At 200 C the leakage current was in the milliAmp range but was still several orders of magnitude lower than the on-state current capabilities of the devices under test. This increase must be considered in the design of circuits using power transistors at elevated temperature. Three circuit topologies have been prototyped using MOSFET's and IGBT's. The circuits were designed using zero current or zero voltage switching techniques to eliminate or minimize hard switching of the power transistors. These circuits have functioned properly over the temperature range. One thousand hour life data have been collected for two power supplies with no failures and no significant change in operating efficiency. While additional reliability testing should be conducted, the feasibility of designing soft switched circuits for operation at 200 C has been successfully demonstrated.

Bromstead, James; Weir, Bennett; Nelms, R. Mark; Johnson, R. Wayne; Askew, Ray

1994-01-01

9

Silicon device performance measurements to support temperature range enhancement  

NASA Technical Reports Server (NTRS)

Semiconductor power devices are typically rated for operation below 150 C. Little data is known for power semiconductors over 150 C. In most cases, the device is derated to zero operating power at 175 C. At the high temperature end of the temperature range, the intrinsic carrier concentration increases to equal the doping concentration level and the silicon behaves as an intrinsic semiconductor. The increase in intrinsic carrier concentration results in a shift of the Fermi level toward mid-bandgap at elevated temperatures. This produces a shift in devices characteristics as a function of temperature. By increasing the doping concentration higher operating temperatures can be achieved. This technique was used to fabricate low power analog and digital devices in silicon with junction operating temperatures in excess of 300 C. Additional temperature effects include increased p-n junction leakage with increasing temperature, resulting in increased resistivity. The temperature dependency of physical properties results in variations in device characteristics. These must be quantified and understood in order to develop extended temperature range operation.

Bromstead, James; Weir, Bennett; Johnson, R. Wayne; Askew, Ray

1991-01-01

10

Silicon device performance measurements to support temperature range enhancement  

NASA Technical Reports Server (NTRS)

The results of the NPN bipolar transistor (BJT) (2N6023) breakdown voltage measurements were analyzed. Switching measurements were made on the NPN BJT, the insulated gate bipolar transistor (IGBT) (TA9796) and the N-channel metal oxide semiconductor field effect transistor (MOSFET) (RFH75N05E). Efforts were also made to build a H-bridge inverter. Also discussed are the plans that have been made to do life testing on the devices, to build an inductive switching test circuit and to build a dc/dc switched mode converter.

Johnson, R. Wayne; Askew, Ray; Bromstead, James; Weir, Bennett

1991-01-01

11

A Modular High-Temperature Measurement Set-Up for Semiconductor Device Characterization  

Microsoft Academic Search

We demonstrate the capabilities of a high temperature measurement set-up recently developed at our institute. It is dedicated to the characterization of semiconductor devices and test structures in the temperature range from room temperature up to 500 degrees C and higher. A detailed description of the experimental aquipment is given. Its practical use is demonstrated by measuring temperature-dependent charcteristics of

Peter Borthen; Gerhard Wachutka

2008-01-01

12

S-Parameter, IV Curve and Noise Figure Measurements of IIIV Devices at Cryogenic Temperatures  

Microsoft Academic Search

We have measured the electrical operating parameters for several three-terminal semiconductor III-V devices at both room temperature and liquid nitrogen temperature, 80 K. The fundamental performance parameters, I-V curve, S-parameters and noise figure, change quite dramatically upon cooling. It is necessary to know these parameters if an optimal cryogenic device, e.g. high-temperature superconducting\\/III-V hybrid, is to be designed and fabricated.

Charles Wilker; Philip S. W. Pang; Charles F. Carter; Zhi-Yuan Shen

1992-01-01

13

A modular high temperature measurement set-up for semiconductor device characterization  

Microsoft Academic Search

We demonstrate the capabilities of a high temperature measurement set-up recently developed at our institute. It is dedicated to the characterization of semiconductor devices and test structures in the temperature range from room temperature up to 500degC and higher. A detailed description of the experimental equipment is given. Its practical use is demonstrated by measuring temperature-dependent characteristics of silicon VDMOSFET

Peter Borthen; Gerhard Wachutka

2007-01-01

14

Silicon Device Performance Measurements to Support Temperature Range Enhancement.  

National Technical Information Service (NTIS)

Testing of the metal oxide semiconductor (MOS)-controlled thyristor (MCT) has uncovered a failure mechanism at elevated temperature. The failure appears to be due to breakdown of the gate oxide. Further testing is underway to verify the failure mode. High...

J. Bromstead B. Weir R. W. Johnson R. Askew

1992-01-01

15

Silicon device performance measurements to support temperature range enhancement  

NASA Astrophysics Data System (ADS)

Testing of the metal oxide semiconductor (MOS)-controlled thyristor (MCT) has uncovered a failure mechanism at elevated temperature. The failure appears to be due to breakdown of the gate oxide. Further testing is underway to verify the failure mode. Higher current level inverters were built to demonstrate 200 C operation of the N-MOSFET's and insulated-gate-bipolar transistors (IGBT's) and for life testing. One MOSFET failed early in testing. The origin of this failure is being studied. No IGBT's have failed. A prototype 28-to-42 V converter was built and is being tested at room temperature. The control loop is being finalized. Temperature stable, high value (10 micro-F) capacitors appear to be the limiting factor in the design at this time. In this application, the efficiency will be lower for the IGBT version due to the large V sub(cesat) (3.5-4 V) compared to the input voltage of 28 V. The MOSFET version should have higher efficiency; however, the MOSFET does not appear to be as robust at 200 C. Both versions are built for comparison.

Bromstead, James; Weir, Bennett; Johnson, R. Wayne; Askew, Ray

1992-05-01

16

Silicon device performance measurements to support temperature range enhancement  

NASA Technical Reports Server (NTRS)

Testing of the metal oxide semiconductor (MOS)-controlled thyristor (MCT) has uncovered a failure mechanism at elevated temperature. The failure appears to be due to breakdown of the gate oxide. Further testing is underway to verify the failure mode. Higher current level inverters were built to demonstrate 200 C operation of the N-MOSFET's and insulated-gate-bipolar transistors (IGBT's) and for life testing. One MOSFET failed early in testing. The origin of this failure is being studied. No IGBT's have failed. A prototype 28-to-42 V converter was built and is being tested at room temperature. The control loop is being finalized. Temperature stable, high value (10 micro-F) capacitors appear to be the limiting factor in the design at this time. In this application, the efficiency will be lower for the IGBT version due to the large V sub(cesat) (3.5-4 V) compared to the input voltage of 28 V. The MOSFET version should have higher efficiency; however, the MOSFET does not appear to be as robust at 200 C. Both versions are built for comparison.

Bromstead, James; Weir, Bennett; Johnson, R. Wayne; Askew, Ray

1992-01-01

17

Sublimation measurements and analysis of high temperature thermoelectric materials and devices  

Microsoft Academic Search

Most severe degradation effects in high temperature (>900°C) thermoelectric devices are due to the sublimation and transposition of the composite materials. Sublimation measurements are compared for various thermoelectric materials. Included in these are advanced high temperature rare-earth sulfides, selenides, and state-of-the-art and improved (with GaP additions) silicon germanium alloys. Although rare-earth calcogenides have the potential for exhibiting excellent sublimation characteristics,

V. Shields; E. L. Noon

1983-01-01

18

An at-sea evaluation of an infrared/resistance temperature device for air/sea-surface temperature measurements  

NASA Astrophysics Data System (ADS)

Air and sea-surface temperatures were measured and recorded by the USS Kitty Hawk's meteorological personnel during a 6-month deployment period. Using infrared/resistance temperature devices (IR/RTD) and hand-held psychrometers, air and sea-surface temperature data were compiled. In comparing these data with data collected earlier by the USS Ranger, it became apparent that the shipboard use of the IR/RTD to measure sea-surface and air temperatures was not warranted. The IR/RTD suffered mechanical and electrical failures during both the USS Kitty Hawk and USSR Ranger measurement periods. Since repair and recalibration must be done at the manufacturer's facility, the device is inappropriate for shipboard use. In addition, the design of the battery-recharging unit does not conform to shipboard requirements for electrical grounding. Borne out by both the comments of the USS Kitty Hawk oceanographer and the large number of highly suspicious readings, additional training for observers is justified. Thus, training on the proper use and care of temperature-measuring devices could be made part of the Aerographer's Mate course curriculum and shipboard performance factors.

Patterson, W. L.

1994-03-01

19

Compensated Temperature Sensing Device.  

National Technical Information Service (NTIS)

A compensated temperature sensing device having a sensing element capable of surviving extreme operating environments while still being able to substantially instantaneously sense temperature changes. This is accomplished by incorporating within the devic...

A. S. Meyer

1980-01-01

20

Laser scanning thermoreflectance imaging system using galvanometric mirrors for temperature measurements of microelectronic devices.  

PubMed

We present a thermoreflectance imaging system using a focused laser sweeping the device under test with a scanner made of galvanometric mirrors. We first show that the spatial resolution of this setup is submicrometric, which makes it adapted to microelectronic thermal measurements. Then, we studied qualitative temperature variations on two dissipative structures constituted of thin (0.35 microm) dissipative resistors, the distance between two resistors being equal to 0.8 or 10 microm. This technique combines sensitivity and speed: it is faster than a point classical thermoreflectance technique and, in addition, more sensitive than a charge-coupled device thermoreflectance imaging technique. PMID:17672785

Grauby, S; Salhi, A; Rampnoux, J-M; Michel, H; Claeys, W; Dilhaire, S

2007-07-01

21

Magnetic relaxation measurement in immunoassay using high-transition-temperature superconducting quantum interference device system  

Microsoft Academic Search

Due to their ultrahigh sensitivity to magnetic flux, superconducting quantum interference devices (SQUIDs) are able to detect biomagnetic signals. By labeling biotargets with magnetic nanoparticles, several groups have shown that SQUIDs are promising as quantitative probes of biotargets by measuring their magnetic properties. In this work, we describe the design and construction of a high-transition-temperature radio-frequency SQUID magnetometer system for

H. C. Yang; S. Y. Yang; G. L. Fang; W. H. Huang; C. H. Liu; S. H. Liao; H. E. Horng; Chin-Yih Hong

2006-01-01

22

Sublimation measurements and analysis of high temperature thermoelectric materials and devices  

NASA Technical Reports Server (NTRS)

High temperature thermoelectric device sublimation effects are compared for rare earth sulfides, selenides, and state-of-the-art Si-Ge alloys. Although rare earth calcogenides can potentially exhibit superior sublimation characteristics, the state-of-the-art Si-Ge alloy with silicon nitride sublimation-inhibitive coating has been tested to 1000 C. Attention is given to the ceramic electrolyte cells, forming within electrical and thermal insulation, which affect leakage conductance measurements in Si-Ge thermoelectric generators.

Shields, V.; Noon, L.

1983-01-01

23

Temporal and spatial temperature measurement in insulator-based dielectrophoretic devices.  

PubMed

Insulator-based dielectrophoresis is a relatively new analytical technique with a large potential for a number of applications, such as sorting, separation, purification, fractionation, and preconcentration. The application of insulator-based dielectrophoresis (iDEP) for biological samples, however, requires the precise control of the microenvironment with temporal and spatial resolution. Temperature variations during an iDEP experiment are a critical aspect in iDEP since Joule heating could lead to various detrimental effects hampering reproducibility. Additionally, Joule heating can potentially induce thermal flow and more importantly can degrade biomolecules and other biological species. Here, we investigate temperature variations in iDEP devices experimentally employing the thermosensitive dye Rhodamin B (RhB) and compare the measured results with numerical simulations. We performed the temperature measurement experiments at a relevant buffer conductivity range commonly used for iDEP applications under applied electric potentials. To this aim, we employed an in-channel measurement method and an alternative method employing a thin film located slightly below the iDEP channel. We found that the temperature does not deviate significantly from room temperature at 100 ?S/cm up to 3000 V applied such as in protein iDEP experiments. At a conductivity of 300 ?S/cm, such as previously used for mitochondria iDEP experiments at 3000 V, the temperature never exceeds 34 C. This observation suggests that temperature effects for iDEP of proteins and mitochondria under these conditions are marginal. However, at larger conductivities (1 mS/cm) and only at 3000V applied, temperature increases were significant, reaching a regime in which degradation is likely to occur. Moreover, the thin layer method resulted in lower temperature enhancement which was also confirmed with numerical simulations. We thus conclude that the thin film method is preferable providing closer agreement with numerical simulations and further since it does not depend on the iDEP channel material. Overall, our study provides a thorough comparison of two experimental techniques for direct temperature measurement, which can be adapted to a variety of iDEP applications in the future. The good agreement between simulation and experiment will also allow one to assess temperature variations for iDEP devices prior to experiments. PMID:24889741

Nakano, Asuka; Luo, Jinghui; Ros, Alexandra

2014-07-01

24

Surface temperature measurements by means of pulsed photothermal effects in fusion devices  

NASA Astrophysics Data System (ADS)

In fusion devices, the surface temperature of plasma facing components is measured using infrared cameras. This method requires a knowledge of the emissivity of the material, the reflected and parasitic fluxes (Bremsstrahlung). For carbon, the emissivity is known and constant over the detection wavelength (3-5 ?m). For beryllium and tungsten, the reflected flux could contribute significantly to the collected flux. The pulsed photothermal method described in this paper allows temperature measurements independently of both reflected and parasitic fluxes. A local increase of the surface temperature (? T 10-15 K) introduced by a laser pulse (few ns) results in an additional component of the photon flux collected by the detector. Few ?s after the pulse, a filtering of the signal allows to extract a temporal flux proportional only to the variation of the emitted flux, the emissivity and ? T. The ratio of simultaneous measurements at two wavelengths leads to the elimination of ? T and emissivity. The range of application increases for measurements at short wavelengths (1-1.7 ?m) with no limitation due to the Bremsstrahlung emission.

Loarer, Th.; Brygo, F.; Gauthier, E.; Grisolia, C.; Le Guern, F.; Moreau, F.; Murari, A.; Roche, H.; Semerok, A.

2007-06-01

25

Device and method for self-verifying temperature measurement and control  

DOEpatents

A measuring instrument includes a first temperature sensor, a second temperature sensor and circuitry. The first and second temperature sensors each generate a signal indicative of the temperature of a medium being detected. The circuitry is configured to activate verification of temperature being sensed with the first sensor. According to one construction, the first temperature sensor comprises at least one thermocouple temperature sensor and the second temperature sensor comprises an optical temperature sensor, each sensor measuring temperature over the same range of temperature, but using a different physical phenomena. Also according to one construction, the circuitry comprises a computer configured to detect failure of one of the thermocouples by comparing temperature of the optical temperature sensor with each of the thermocouple temperature sensors. Even further, an output control signal is generated via a fuzzy inference machine and control apparatus.

Watkins, Arthur D. (Idaho Falls, ID); Cannon, Collins P. (Kearney, MO); Tolle, Charles R. (Idaho Falls, ID)

2002-10-29

26

A new device for high precision in situ sediment temperature profile measurements at the seafloor  

NASA Astrophysics Data System (ADS)

In situ sediment temperature profile measurements at the seafloor provide valuable information on fluid seepage, hydrate stability, and ambient temperature of samples. In addition, it can be convenient to approximate other parameters such as concentrations of porewater constituents from temperature or temperature gradient using transfer functions if their distribution is controlled by the same processes and direct quantification involves time-consuming sampling and laboratory analyses. We present a new instrument that can be used to obtain precisely positioned sediment temperature profile measurements from the seafloor during ROV dives. Consisting of a 0.4 m-long sensor rod equipped with eight temperature sensors and a standard data logger, the new T-Stick can be operated by an ROV in a fully autonomous mode. The temperature range of the instrument is -5 C to 35 C and it can withstand pressures of up to 600 bar. Compared to previously used instruments, the smaller diameter of the new T-Stick reduces the thermal inertia of the lance and results in shorter equilibration times. Virtual measurements generated by a numerical model showed that the T-Stick provides highly accurate temperature profile measurements with a root mean square error of 0.0027 K for a wide range of thermal sediment properties. Modeled temperature gradients are representative of both normal deep sea settings and cold seep environments with elevated temperature gradients of up to three orders of magnitude above normal background values, which are the primary target areas for T-Stick measurements. Deviations from the true in situ temperature profiles are caused by disturbance of the temperature field by the probe itself and may lead to underestimation of gradients and curvature in the profiles. A first field test of the T-Stick was conducted at the Hkon Mosby mud volcano at 1250 m water depth on the Barents Sea slope, where the new instrument provided useful information about the origin and extent of freshly erupted mud.

Feseker, T.; Wetzel, G.; Heesemann, B.

2012-04-01

27

The measurement of the glass transition temperature of mesophase pitches using a thermomechanical device  

Microsoft Academic Search

A thermomechanical analysis (TMA) technique is presented for the measurement of the glass transition temperature (Tg) of glassy pitch materials. Pitches with varying mesophase content have been used for the Tg determination. In this technique, the linear expansion of a mesophase pitch sample with respect to temperature is determined by means of a dilatometer. The change in the coefficient of

P. M. Khandare; J. W. Zondlo; A. S. Pavlovic

1996-01-01

28

A robust and well shielded thermal conductivity device for low temperature measurements  

NASA Astrophysics Data System (ADS)

We present a compact mechanically robust thermal conductivity measurement apparatus for measurements at low temperatures (<1 K) and high magnetic fields on small high-purity single crystal samples. A high-conductivity copper box is used to enclose the sample and all the components. The box provides protection for the thermometers, heater, and most importantly the sample increasing the portability of the mount. In addition to physical protection, the copper box is also effective at shielding radio frequency electromagnetic interference and thermal radiation, which is essential for low temperature measurements. A printed circuit board in conjunction with a braided ribbon cable is used to organize the delicate wiring and provide mechanical robustness.

Toews, W. H.; Hill, R. W.

2014-04-01

29

Localized Heating on Silicon Field Effect Transistors: Device Fabrication and Temperature Measurements in Fluid  

PubMed Central

We demonstrate electrically addressable localized heating in fluid at the dielectric surface of silicon-on-insulator field-effect transistors via radio-frequency Joule heating of mobile ions in the Debye layer. Measurement of fluid temperatures in close vicinity to surfaces poses a challenge due to the localized nature of the temperature profile. To address this, we developed a localized thermometry technique based on the fluorescence decay rate of covalently attached fluorophores to extract the temperature within 2 nm of any oxide surface. We demonstrate precise spatial control of voltage dependent temperature profiles on the transistor surfaces. Our results introduce a new dimension to present sensing systems by enabling dual purpose silicon transistor-heaters that serve both as field effect sensors as well as temperature controllers that could perform localized bio-chemical reactions in Lab on Chip applications.

Elibol, Oguz H.; Reddy, Bobby; Nair, Pradeep R.; Dorvel, Brian; Butler, Felice; Ahsan, Zahab; Bergstrom, Donald E.; Alam, Muhammad A.; Bashir, Rashid

2010-01-01

30

Pulse flux measuring device  

DOEpatents

A device for measuring particle flux comprises first and second photodiode detectors for receiving flux from a source and first and second outputs for producing first and second signals representing the flux incident to the detectors. The device is capable of reducing the first output signal by a portion of the second output signal, thereby enhancing the accuracy of the device. Devices in accordance with the invention may measure distinct components of flux from a single source or fluxes from several sources.

Riggan, William C. (Albuquerque, NM) [Albuquerque, NM

1985-01-01

31

Temperature differential detection device  

DOEpatents

A temperature differential detection device for detecting the temperature differential between predetermined portions of a container wall is disclosed as comprising a Wheatstone bridge circuit for detecting resistance imbalance with a first circuit branch having a first elongated wire element mounted in thermal contact with a predetermined portion of the container wall, a second circuit branch having a second elongated wire element mounted in thermal contact with a second predetermined portion of a container wall with the wire elements having a predetermined temperature-resistant coefficient, an indicator interconnected between the first and second branches remote from the container wall for detecting and indicating resistance imbalance between the first and second wire elements, and connector leads for electrically connecting the wire elements to the remote indicator in order to maintain the respective resistance value relationship between the first and second wire elements. The indicator is calibrated to indicate the detected resistance imbalance in terms of a temperature differential between the first and second wall portions.

Girling, Peter M. (Allentown, PA) [Allentown, PA

1986-01-01

32

A robust and well shielded thermal conductivity device for low temperature measurements.  

PubMed

We present a compact mechanically robust thermal conductivity measurement apparatus for measurements at low temperatures (<1 K) and high magnetic fields on small high-purity single crystal samples. A high-conductivity copper box is used to enclose the sample and all the components. The box provides protection for the thermometers, heater, and most importantly the sample increasing the portability of the mount. In addition to physical protection, the copper box is also effective at shielding radio frequency electromagnetic interference and thermal radiation, which is essential for low temperature measurements. A printed circuit board in conjunction with a braided ribbon cable is used to organize the delicate wiring and provide mechanical robustness. PMID:24784624

Toews, W H; Hill, R W

2014-04-01

33

Experimental device to measure the electrical and optical properties of radiochromic films as a function of temperature  

NASA Astrophysics Data System (ADS)

In the last decade, radiochromic films (RCF) have been used extensively in medical physics for evaluating uniformity of radiation beams and dose distributions. These films are very sensitive to changes in temperature; therefore, one needs to know its thermal behavior to use them efficiently. Normally, the thermal assessment is done using optical methods on previously irradiated samples. Here, we report the use of a complementary dielectric method. We designed an experimental device that allows us to measure, simultaneously, the dielectric and optical properties as a function of temperature. We performed the measurements in real-time to temperature increases from 27 to 48 C of EBT and MD-55 RCF previously exposed to UV. We found for both films a decrease in the real part of the dielectric permittivity as the temperature increases, but an increment and decrease in the dielectric loss factor for the EBT and MD-55 film, respectively.

Gmez-Galvn, F.; Mercado-Uribe, H.

2009-06-01

34

Portable emittance measurement device  

SciTech Connect

In Institute for Theoretical and Experimental Physics (ITEP) the portable emittance measurements device is developed. It provides emittance measurements both with ''pepper-pot'' and ''two slits'' methods. Depending on the method of measurements, either slits or pepper-pot mask with scintillator are mounted on the two activators and are installed in two standard Balzer's cross chamber with CF-100 flanges. To match the angle resolution for measured beam, the length of the stainless steel pipe between two crosses changes is adjusted. The description of the device and results of emittance measurements at the ITEP ion source test bench are presented.

Liakin, D.; Seleznev, D.; Orlov, A.; Kuibeda, R.; Kropachev, G.; Kulevoy, T.; Yakushin, P. [Institute for Theoretical and Experimental Physics, Moscow 117218 (Russian Federation)

2010-02-15

35

Portable emittance measurement device.  

PubMed

In Institute for Theoretical and Experimental Physics (ITEP) the portable emittance measurements device is developed. It provides emittance measurements both with "pepper-pot" and "two slits" methods. Depending on the method of measurements, either slits or pepper-pot mask with scintillator are mounted on the two activators and are installed in two standard Balzer's cross chamber with CF-100 flanges. To match the angle resolution for measured beam, the length of the stainless steel pipe between two crosses changes is adjusted. The description of the device and results of emittance measurements at the ITEP ion source test bench are presented. PMID:20192459

Liakin, D; Seleznev, D; Orlov, A; Kuibeda, R; Kropachev, G; Kulevoy, T; Yakushin, P

2010-02-01

36

Measuring Temperature  

NSDL National Science Digital Library

This is a lesson about measuring temperature. Learners will apply their knowledge of how temperature affects matter to understand how a thermometer works. They then read about the history of the thermometer and the temperature scales that make the information from the thermometer meaningful. The lesson models scientific inquiry using the 5E instructional model and includes teacher notes, prerequisite concepts, common misconceptions, student journal and reading. This is lesson 6 in the Astro-Venture Astronomy Unit. The lessons are designed for educators to use in conjunction with the Astro-Venture multimedia modules.

37

Neutral gas temperatures measured within a high-density, inductively coupled plasma abatement device  

NASA Astrophysics Data System (ADS)

The neutral temperature within a cylindrical, inductively coupled plasma source has been studied for rare gas and molecular plasmas using the technique of optical emission thermometry. By adding small quantities of N2 to the gas feeds as an actinometer, the neutral temperature of the discharge can be estimated by simulation and fitting of the rotationally unresolved second positive band (C3Pi]u-B3[Pig). In this work, the neutral temperature was estimated using this technique for flowing discharges of argon, helium, neon, nitrogen, and oxygen as a function of pressure and power. It was found that the neutral temperature for all of the discharges studied increased roughly proportional to the logarithm of the pressure. An increase in neutral temperature was also observed with increases in power; however, the dependence did not follow a simple functional form. The rare gases exhibited temperatures significantly above room temperature under high power (1200 W) and high pressure (approx1 Torr) conditions with argon approaching 2000 K. Molecular discharges such as N2 and O2 exhibited significantly higher temperatures (approaching 2500 K) than the rare gases even though they are expected to have lower plasma densities at the same pressure and power. It is believed that Franck-Condon heating of the gases during electron impact dissociation, vibrational excitation/thermalization, and exothermic wall reactions may all play important roles in producing such elevated temperatures. Simple, zero-dimensional plasma modeling indicates that neutral temperature elevation will result in significant increases in discharge electron temperature and electron-impact reaction rate coefficients under the same operating conditions. copyright 2002 American Vacuum Society.

Tonnis, Eric J.; Graves, David B.

2002-09-01

38

High temperature superconductor micro-superconducting-quantum-interference-device magnetometer for magnetization measurement of a microscale magnet.  

PubMed

We have developed a high temperature superconductor (HTS) micrometer-sized dc superconducting quantum interference device (SQUID) magnetometer for high field and high temperature operation. It was fabricated from YBa2Cu3O7-delta of 92 nm in thickness with photolithography techniques to have a hole of 4x9 microm2 and 2 microm wide grain boundary Josephson junctions. Combined with a three dimensional magnetic field coil system, the modulation patterns of critical current Ic were observed for three different field directions. They were successfully used to measure the magnetic properties of a molecular ferrimagnetic microcrystal (23x17x13 microm3), [Mn2(H2O)2(CH3COO)][W(CN)8]2H2O. The magnetization curve was obtained in magnetic field up to 0.12 T between 30 and 70 K. This is the first to measure the anisotropy of hysteresis curve in the field above 0.1 T with an accuracy of 10(-12) J T(-1) (10(-9) emu) with a HTS micro-SQUID magnetometer. PMID:18377027

Takeda, Keiji; Mori, Hatsumi; Yamaguchi, Akira; Ishimoto, Hidehiko; Nakamura, Takayoshi; Kuriki, Shinya; Hozumi, Toshiya; Ohkoshi, Shin-ichi

2008-03-01

39

Inducer Hydrodynamic Load Measurement Devices  

NASA Technical Reports Server (NTRS)

Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This "rotating balance" was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

Skelley, Stephen E.; Zoladz, Thomas F.

2002-01-01

40

Optical displacement measuring device  

Microsoft Academic Search

Theoretical considerations of a lightweight, frictionless, optical displacement measuring device (ODMD) are discussed. Experimental results show its resolution and accuracy to be better than 2.5 x 10 to the -8th m with a linear range of 7.5 x 10 to the -5th m, and less than 0.2% change of voltage signal in 600 hours; it has high cycling ability, no

G. F. Weissmann; H. L. Carter Jr.; R. R. Hart

1979-01-01

41

High temperature superconductor micro-superconducting-quantum-interference-device magnetometer for magnetization measurement of a microscale magnet  

Microsoft Academic Search

We have developed a high temperature superconductor (HTS) micrometer-sized dc superconducting quantum interference device (SQUID) magnetometer for high field and high temperature operation. It was fabricated from YBa2Cu3O7-delta of 92 nm in thickness with photolithography techniques to have a hole of 49 mum2 and 2 mum wide grain boundary Josephson junctions. Combined with a three dimensional magnetic field coil system,

Keiji Takeda; Hatsumi Mori; Akira Yamaguchi; Hidehiko Ishimoto; Takayoshi Nakamura; Shinya Kuriki; Toshiya Hozumi; Shin-Ichi Ohkoshi

2008-01-01

42

Capacitance measuring device  

DOEpatents

A capacitance measuring circuit is provided in which an unknown capacitance is measured by comparing the charge stored in the unknown capacitor with that stored in a known capacitance. Equal and opposite voltages are repetitively simultaneously switched onto the capacitors through an electronic switch driven by a pulse generator to charge the capacitors during the ''on'' portion of the cycle. The stored charge is compared by summing discharge currents flowing through matched resistors at the input of a current sensor during the ''off'' portion of the switching cycle. The net current measured is thus proportional to the difference in value of the two capacitances. The circuit is capable of providing much needed accuracy and stability to a great variety of capacitance-based measurement devices at a relatively low cost.

Andrews, W.H. Jr.

1984-08-01

43

Temperature measurement  

MedlinePLUS

... Academy of Pediatrics (AAP) recommends against using glass thermometers with mercury. The glass can break, and mercury is a poison. Electronic thermometers are the most recommended type. The temperature is ...

44

Thermography: a new measuring device for the determination of temperature distribution on chamber walls of coke ovens  

SciTech Connect

It is particularly difficult to measure the heat distribution over chamber walls of coke ovens since the surfaces involved are not readily accessible, measurements have to be taken from outside through a door opening, and no more than two minutes are available for scanning both of the chamber walls before the doors have to be refitted. This paper describes infrared thermography and the adaptation of this technique to the specific task of temperature measurement of oven walls. An improved infrared camera is mounted on a mobile platform and passes in front of the open chamber at a preset speed. The camera continuously scans the temperatures towards the vertical chamber axis. The data is processed by computer which prints a thermal diagram. With this system it is possible to take all the measurements of an oven battery in one or two days. The measuring method could also be applied to other temperature measurements involved in the operation of coke oven batteries. (CKK)

Eisenhut, W.; Sarangi, B.

1982-01-01

45

Temperature monitoring device and thermocouple assembly therefor  

DOEpatents

A temperature monitoring device for measuring the temperature at a surface of a body, composed of: at least one first thermocouple and a second thermocouple; support members supporting the thermocouples for placing the first thermocouple in contact with the body surface and for maintaining the second thermocouple at a defined spacing from the body surface; and a calculating circuit connected to the thermocouples for receiving individual signals each representative of the temperature reading produced by a respective one of the first and second thermocouples and for producing a corrected temperature signal having a value which represents the temperature of the body surface and is a function of the difference between the temperature reading produced by the first thermocouple and a selected fraction of the temperature reading provided by the second thermocouple.

Grimm, Noel P. (Monroeville, PA); Bauer, Frank I. (Perry Township, Lawrence County, PA); Bengel, Thomas G. (Plum Boro, PA); Kothmann, Richard E. (Churchill Boro, PA); Mavretish, Robert S. (New Stanton, PA); Miller, Phillip E. (Greensburg, PA); Nath, Raymond J. (Murrysville, PA); Salton, Robert B. (Plum Boro, PA)

1991-01-01

46

Measuring device for synchrotron X-ray imaging and first results of high temperature polymer electrolyte membrane fuel cells  

Microsoft Academic Search

In this paper, a measurement cell for recording synchrotron X-ray images of low and high temperature PEM fuel cells is described. The experimental setup allows for recording of cross-sectional images, as well as for radiograms in through-plane direction, with limited signal degradation. First results on H3PO4 concentration and distribution as a function of the operating conditions are presented.This basic cell

R. Kuhn; J. Scholta; Ph. Krger; Ch. Hartnig; W. Lehnert; T. Arlt; I. Manke

2011-01-01

47

Jaw bite force measurement device.  

PubMed

We describe a cost-effective device that uses an off-the-shelf force transducer to measure patient bite force as a diagnostic aid in determining dental implant size, number of implants, and prosthetic design for restoring partial edentulism. The main advantages of the device are its accuracy, simplicity, modularity, ease of manufacturing, and low cost. PMID:20822470

Flanagan, Dennis; Ilies, Horea; O'Brien, Brendan; McManus, Anne; Larrow, Beau

2012-08-01

48

Improved Phase Measuring Device.  

National Technical Information Service (NTIS)

This document discloses an improved phase measuring method and apparatus for measuring the relative phase and amplitude of an applied optical signal beam at a number of points in a plane. The combination of the signal beam and a reference beam are simulta...

J. S. Shreve

1978-01-01

49

Phase Measuring Device.  

National Technical Information Service (NTIS)

This invention relates to an improved phase measuring method and apparatus for measuring the relative phase and amplitude of an applied optical signal beam at a number of points in a plane. The combination of the signal beam and a reference beam are simul...

J. S. Shreve

1980-01-01

50

Mirror Measurement Device  

NASA Technical Reports Server (NTRS)

A Small Business Innovation Research (SBIR) contract led to a commercially available instrument used to measure the shape profile of mirror surfaces in scientific instruments. Bauer Associates, Inc.'s Bauer Model 200 Profilometer is based upon a different measurement concept. The local curvature of the mirror's surface is measured at many points, and the collection of data is computer processed to yield the desired shape profile. (Earlier profilometers are based on the principle of interferometry.) The system is accurate and immune to problems like vibration and turbulence. Two profilometers are currently marketed, and a third will soon be commercialized.

1992-01-01

51

Si MOS devices at low temperatures  

NASA Technical Reports Server (NTRS)

Low temperature operation of micron and submicron size Si MOSFETs (metal-oxide-semiconductor field-effect-transistors) results in their improved device characteristics. Various low temperature device properties such as increase in mobility, shift in the theshold voltage, increased reliability, etc., were considered. Other device characteristics such as the subthreshold behavior, delay times and miniaturization at low temperatures are discussed. Discussion includes presenting experimental results along with physical models explaining the observed effects.

Kamgar, A.

1984-01-01

52

Inducer Hydrodynamic Load Measurement Devices.  

National Technical Information Service (NTIS)

Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six-component wind tunnel balance - senses the forces and moments on the rota...

S. E. Skelley T. F. Zoladz

2002-01-01

53

Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets  

NASA Astrophysics Data System (ADS)

This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets.

Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

2013-06-01

54

Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets.  

PubMed

This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets. PMID:23822369

Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

2013-06-01

55

Direct temperature mapping of nanoscale plasmonic devices.  

PubMed

Side by side with the great advantages of plasmonics in nanoscale light confinement, the inevitable ohmic loss results in significant joule heating in plasmonic devices. Therefore, understanding optical-induced heat generation and heat transport in integrated on-chip plasmonic devices is of major importance. Specifically, there is a need for in situ visualization of electromagnetic induced thermal energy distribution with high spatial resolution. This paper studies the heat distribution in silicon plasmonic nanotips. Light is coupled to the plasmonic nanotips from a silicon nanowaveguide that is integrated with the tip on chip. Heat is generated by light absorption in the metal surrounding the silicon nanotip. The steady-state thermal distribution is studied numerically and measured experimentally using the approach of scanning thermal microscopy. It is shown that following the nanoscale heat generation by a 10 mW light source within a silicon photonic waveguide the temperature in the region of the nanotip is increased by ? 15 C compared with the ambient temperature. Furthermore, we also perform a numerical study of the dynamics of the heat transport. Given the nanoscale dimensions of the structure, significant heating is expected to occur within the time frame of picoseconds. The capability of measuring temperature distribution of plasmonic structures at the nanoscale is shown to be a powerful tool and may be used in future applications related to thermal plasmonic applications such as control heating of liquids, thermal photovoltaic, nanochemistry, medicine, heat-assisted magnetic memories, and nanolithography. PMID:24422562

Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

2014-02-12

56

Fluid Pressure Measuring Device Interface.  

National Technical Information Service (NTIS)

A fluid pressure measuring device interface which may be used in a submersible platform or vehicle includes an interface chamber fluidly coupled to a conduit which leads to the fluid medium whose pressure is to be measured. The interface chamber encloses ...

D. W. French

1997-01-01

57

Temperature controller for hyperthermia devices  

NASA Technical Reports Server (NTRS)

Temperature controller monitors and controls temperature in local region of tumor. Medical grade thermocouples are inserted in or near tumor, controller pulse modulates radio frequency diathermy power source to maintain temperature within 0.2 C. System may be extended to control diathermy of more than one tumor or patient.

Couch, R. H.; Hearn, C. P.; Williams, J. B.

1980-01-01

58

Edge turbulence measurements in toroidal fusion devices  

Microsoft Academic Search

This paper reviews measurements of edge plasma turbulence in toroidal magnetic fusion devices with an emphasis on recent results in tokamaks. The dominant feature of edge turbulence is a high level of broadband density fluctuations with a relative amplitude deltan\\/n ~ 5 100%, accompanied by large potential and electron temperature fluctuations. The frequency range of this turbulence is ~10 kHz

S. J. Zweben; J. A. Boedo; O. Grulke; C. Hidalgo; B. La Bombard; R. J. Maqueda; P. Scarin; J. L. Terry

2007-01-01

59

Beta ray flux measuring device  

DOEpatents

A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

Impink, Jr., Albert J. (Murrysville, PA); Goldstein, Norman P. (Murrysville, PA) [Murrysville, PA

1990-01-01

60

Microwave applications of high-temperature superconductor devices  

Microsoft Academic Search

Three topics are reviewed for microwave application of high-temperature superconductor (HTS) devices; measurement method of surface resistance Rs of high-temperature superconductor films and bulks, phenomenological explanation of Rs by three fluid model, and microwave HTS filters of various types. Microwave applications of high-temperature superconductor devices Yoshio Kobayashi Saitama University, Urawa, Saitama 338, Japan. Summary Three topics are reviewed for microwave

Yoshio Kobayashi

1996-01-01

61

Spring-force measuring device  

SciTech Connect

A device is described for measuring the spring-force of resilient spacer projections set into spacer grids of nuclear reactor fuel assemblies to push fuel rods surrounded by spacer meshes against at least two oppositely disposed rigid spacer projections. It includes a force measuring plug having a diameter equal to the diameter of a fuel rod to be fixed in the spacer grid, and a flexible beam integral with the force measuring plug. The flexible beam has a free end in contact with a first resilient spacer projection to be measured, and another end firmly connected to the force measuring plug and has at least one wire strain gage disposed thereon.

Bezold, H.; Steven, J.

1981-01-27

62

New diesel injection nozzle flow measuring device  

NASA Astrophysics Data System (ADS)

A new measuring device has been developed for diesel injection nozzle testing, allowing measuring of the steady flow through injection nozzle and the injection rate. It can be best applied for measuring the low and high injection rates of the pintle and single hole nozzle. In steady flow measuring the fuel pressure at the inlet of the injection nozzle is 400 bar. The sensor of the measuring device measures the fuel charge, resulting from fuel rubbing in the fuel injection system, as well as from the temperature gradient in the sensor electrode. The electric charge is led to the charge amplifier, where it is converted into electric current and amplified. The amplifier can be used also to measure the mean injection rate value.

Mar?i?, Milan

2000-04-01

63

Power loss and junction temperature analysis of power semiconductor devices  

Microsoft Academic Search

A newly developed electrothermal calculation method is implemented to estimate the power loss and working temperature of insulated gate bipolar transistor (IGBT) devices. Based on the measurement of the IGBT's characteristics, the exact estimation of power loss considering the junction temperature is introduced. Then, the thermal network is used to calculate the working temperature. The comparison between experimental and calculation

Dewei Xu; Haiwei Lu; Lipei Huang; Satoshi Azuma; Masahiro Kimata; Ryohei Uchida

2002-01-01

64

Fabrication of a high temperature superconductor micro-superconducting-quantum-interference-device magnetometer for magnetic hysteresis measurements  

Microsoft Academic Search

A high-temperature-superconductor-type micrometer-sized dc-SQUID (SQUID denotes superconducting quantum interference divice) magnetometer with much higher sensitivity than a commercial system has been developed. Several kinds of YBa2Cu3O7-delta micro-SQUIDs were fabricated with photolithography techniques to have a hole of 49 mum2 and 2-mum-wide grain boundary Josephson junctions. Combined with a three dimensional magnetic field coil system, the voltage modulation was observed for

Keiji Takeda; Hatsumi Mori; Akira Yamaguchi; Hidehiko Ishimoto; Takayoshi Nakamura; Shinya Kuriki; Toshiya Hozumi; Shin-Ichi Ohkoshi

2008-01-01

65

Pressure measurements in magnetic-fusion devices  

SciTech Connect

Accurate pressure measurements are important in magnetic fusion devices for: (1) plasma diagnostic measurements of particle balance and ion temperature; (2) discharge cleaning optimization; (3) vacuum system performance; and (4) tritium accountability. This paper reviews the application, required accuracy, and suitable instrumentation for these measurements. Demonstrated uses of ionization-type and capacitance-diaphragm gauges for various pressure and gas-flow measurements in tokamaks are presented, with specific reference to the effects of magnetic fields on gauge performance and the problems associated with gauge calibration.

Dylla, H.F.

1981-11-01

66

Development of a Low-Temperature Insert for Precise Magnetization Measurement below T = 2 K with a Superconducting Quantum Interference Device Magnetometer  

NASA Astrophysics Data System (ADS)

We have developed a 9-mm-diameter 3He insert for precise magnetization measurements below T = 2 K that is attachable to a commercial superconducting quantum interference device magnetometer. The insert is made from a thin-walled stainless steel pipe with an inner diameter of 6.2 mm, which determines the maximum sample size. 3He gas is condensed in the pipe, which is liquefied by 4He gas at T 1.8 K generated by the magnetometer via the heat exchanger of a Cu vacuum jacket with an outer diameter of 8.6 mm soldered to the stainless steel pipe. The temperature of the insert is decreased to T 0.5 K by evacuating liquid 3He using a rotary pump and then to T = 0.36 K with a sorption pump. From the diamagnetization signal of a superconducting Al chip with a mass below 0.1 mg, the magnetization resolution with the insert is confirmed to be less than 10-7 emu. To examine the performance of the insert, we measured the temperature dependence of the magnetic susceptibility and magnetization for Pr0.6La0.4Ag2In down to T = 0.4 K.

Sato, Yoshiaki; Makiyama, Shun; Sakamoto, Yasutaka; Hasuo, Tadahiko; Inagaki, Yuji; Fujiwara, Tetsuya; Suzuki, Hiroyuki S.; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Kawae, Tatsuya

2013-10-01

67

Precise temperature control for measurement purposes  

Microsoft Academic Search

At the beginning we discuss a few models of electrothermal devices intended for the measurements of thermal parameters of materials, components or devices. A solution to the task of optimal control of furnace batch temperature is presented. On the basis of a multisectional thermal system model with equivalent delays, the solution to the reactor batch optimal temperature control is found.

M. Orzylowski; T. Kaluzniacki; Z. Rudolf; G. Nowicki

1999-01-01

68

Core temperature measurement in carbothermal reduction processes  

Microsoft Academic Search

An accurate temperature measurement of the core in carbothermal reduction processes, such as boron and silicon carbide manufacturing processes, is not only important from product quality viewpoint but also quite a challenging task. The core temperature in these processes ranges 2200 to 3000K. In this study, a device has been designed to measure the core temperature. Much attention has been

M. P. L. N. Rao; G. S. Gupta; P. Manjunath; S. Kumar; A. K. Suri; N. Krishnamurthy; C. Subramanian

2009-01-01

69

Versatile low-temperature atomic force microscope with in situ piezomotor controls, charge-coupled device vision, and tip-gated transport measurement capability  

NASA Astrophysics Data System (ADS)

A versatile cryogenic (5 K) ultrahigh-vacuum (UHV) atomic force microscope (AFM) with tip-gated transport measurement capability has been developed. Using high-resolution (<1.5 ?m) plan-view charge-coupled device (CCD) optics, and three planar piezomotors we achieved visually guided in situ alignments of a sample position with respect to the AFM tip, and the laser beam position with respect to the cantilever and the quadrant photodiode. We made optical fiber feedthroughs and a laser lens assembly to bring external laser light and CCD illuminating light onto the cantilever and the sample. A sample holder with an embedded temperature sensor and eight transport electrodes is detachably mounted on a piezotube scanner. The generic cantilever mount can be easily replaced with a tuning-fork mount or a piezoresistive cantilever mount for experiments where stray laser light should be avoided. To our knowledge, this is the first Dewar-immersion type cryogenic AFM with laser beam deflection sensing capability and high-resolution plan-view CCD optics.

Lee, Jhinhwan; Chae, Jungseok; Kim, Chung Koo; Kim, Hyunjin; Oh, Seungeun; Kuk, Young

2005-09-01

70

Measuring Temperature Reading  

NASA Technical Reports Server (NTRS)

There are two requirements for taking a measurement of something. The first is a tool for taking a measurement. The second is scale for making sense of the numbers of the measurement. For example, a ruler is often used to measure short lengths. It is the tool for measurement. On the ruler are one or more number scales with equally spaced numbers. These numbers can be compared with numbers from any other ruler that is accurately set to the same scale. Measuring length is far simpler than measuring temperature. While there is evidence of tools for measuring length at various times in human history, tools and scales for measuring temperature do not appear until more recent human history. Early thermometers, called thermoscopes, first appear in the 1500's. They were crude instruments that were not at all accurate. Most did not even have a number scale associated with them. This made them useless for most practical purposes. Gabriel Fahrenheit created the first accurate thermometer in 1714, and the Fahrenheit temperature scale followed it in 1724. The thermometer s accuracy was based on its use of mercury, a silver colored substance that remains liquid over a wide range of temperatures but expands or contracts in a standard, predictable way with changes in temperature. To set the scale, Fahrenheit created the coldest temperature that he could. He mixed equal parts of ice, water, and salt, and then used this as the zero point, 0 degrees, of his scale. He intended to make 30 degrees the freezing point of water and 90 degrees the temperature of the human body, but he had to later revise these temperatures to be 32 degrees and 96 degrees. In the final version of the scale, the temperature of the human body became 98.6 degrees. 19th century thermoscope

2003-01-01

71

Smart thermocouple system for industrial temperature measurement  

Microsoft Academic Search

A smart temperature measurement system is described which takes advantage of known sensor performance characteristics to improve industrial temperature measurement. The sensor includes provisions for integrating information into the sensor via an internal memory device. Complementary software and instrumentation then utilizes this information during field operation. Improvements include performance benefits such as reduced measurement uncertainty, increased robustness, and failure prediction

B. Schuh

2001-01-01

72

Nonvisual Adaptive Devices for Measuring Insulin.  

ERIC Educational Resources Information Center

This article presents information on nonvisual adaptive devices for measuring insulin and offers some suggestions for rehabilitation professionals who instruct and supervise clients with diabetes and visual impairment in the use of these devices. (Author)

Cleary, M. E.; Hamilton, J. E.

1993-01-01

73

Thermospheric temperature measurement technique.  

NASA Technical Reports Server (NTRS)

A method for measurement of temperature in the earth's lower thermosphere from a high-velocity probes is described. An undisturbed atmospheric sample is admitted to the instrument by means of a free molecular flow inlet system of skimmers which avoids surface collisions of the molecules prior to detection. Measurement of the time-of-flight distribution of an initially well-localized group of nitrogen metastable molecular states produced in an open, crossed electron-molecular beam source, yields information on the atmospheric temperature. It is shown that for high vehicle velocities, the time-of-flight distribution of the metastable flux is a sensitive indicator of atmospheric temperature. The temperature measurement precision should be greater than 94% at the 99% confidence level over the range of altitudes from 120-170 km. These precision and altitude range estimates are based on the statistical consideration of the counting rates achieved with a multichannel analyzer using realistic values for system parameters.

Hueser, J. E.; Fowler, P.

1972-01-01

74

Measuring the Curie temperature  

NASA Astrophysics Data System (ADS)

The measurement of Curie or Nel temperatures is one of the central techniques in rock magnetism, because it is a relatively fast and reliable method to determine the predominant magnetic minerals in natural samples, even if their concentrations are relatively small. Unfortunately, the results of different commonly used measurement protocols for the same sample can deviate enough to be confusing. Serious problems occur especially for studies which interpret differences in Curie temperatures obtained from M(T)- and ?(T)- measurements, and many of these results must be questioned, or even disregarded. Primarily this is due to insufficient theoretical foundation, leading to incompatible TC values when determinations by different measurements are evaluated by the same or similar methods. Using Landau theory for in-field magnetization measurements, high-temperature measurement procedures are studied to revise the common evaluation routines for M(T)- and ?(T)-curves. While at least four different physical processes can contribute to the low-field initial susceptibility near the ordering temperature, each of which may influence the apparent position of TC, high-field methods are better defined, but do not truly trace a second-order phase transition. Here, a series of theoretical calculations are compared to high-temperature VSM measurements of quarter-hysteresis loops, a procedure developed to efficiently measure several hysteresis parameters in a single heating cycle. This method is equally as fast as a typical TC determination on a Curie balance and provides a considerable amount of additional information which can be modeled to obtain a more robust Curie Temperature.

Fabian, K.; Shcherbakov, V. P.; McEnroe, S. A.

2012-04-01

75

Measuring the Curie temperature  

NASA Astrophysics Data System (ADS)

Curie point temperatures (TC) of natural and synthetic magnetic materials are commonly determined in rock magnetism by several measurement methods that can be mutually incompatible and may lead to inconsistent results. Here the common evaluation routines for high-temperature magnetization and magnetic initial susceptibility curves are analyzed and revised based on Landau's theory of second-order phase transitions. It is confirmed that in high-field magnetization curves TC corresponds to the inflection point, below the temperature of maximum curvature or the double-tangent intersection point. At least four different physical processes contribute to the initial magnetic susceptibility near the ordering temperature. They include variation of saturation magnetization, superparamagnetic behavior, magnetization rotation, and magnetic domain wall motion. Because each of these processes may influence the apparent position of TC, initial susceptibility and high-field curves can yield deviating estimates of TC. A new procedure is proposed to efficiently determine the temperature variation of several magnetic parameters on a vibrating-sample magnetometer, by repeatedly measuring quarter-hysteresis loops during a single heating cycle. This procedure takes measurements during the inevitable waiting time necessary for thermal equilibration of the sample, whereby it is not slower than the commonly performed measurements on a Curie balance. However, it returns saturation magnetization, saturation remanence, high-field and low-field slopes, and other parameters as a function of temperature, which provide independent information about TC and other sample properties.

Fabian, K.; Shcherbakov, V. P.; McEnroe, S. A.

2013-04-01

76

Dynamic Surface Temperature Measurements in ICs  

Microsoft Academic Search

Measuring techniques of the die surface temperature in integrated circuits are reported as very appropriate for failure analysis, for thermal characterization, and for testing modern devices. The paper is arranged as a survey of techniques oriented towards measuring the temperature dynamics of the circuit surface and presenting and discussing both the merits and drawbacks of each technique with regard to

Josep Altet; Wilfrid Claeys; Stefan Dilhaire; Antonio Rubio

2006-01-01

77

Design parameter evaluation of a metal recoated Fiber Bragg Grating sensors for measurement of cryogenic temperature or stress in superconducting devices  

Microsoft Academic Search

There are plenty of complex physical phenomena which remain to be studied and verified experimentally for building an optimized superconducting magnet. The main problem for experimental validations is due to the unavailability of suitable sensors. This paper proposes a Fiber Bragg Gratings (FBG) sensor for this purpose which allows access to the local temperature\\/stress state. To measure the low temperature

R. Rajinikumar; M. Ser; K. G. Narayankhedkar; G. Krieg; M. D. Atrey

2009-01-01

78

Versatile low-temperature atomic force microscope with in situ piezomotor controls, charge-coupled device vision, and tip-gated transport measurement capability  

Microsoft Academic Search

A versatile cryogenic (5 K) ultrahigh-vacuum (UHV) atomic force microscope (AFM) with tip-gated transport measurement capability has been developed. Using high-resolution (<1.5 mum) plan-view charge-coupled device (CCD) optics, and three planar piezomotors we achieved visually guided in situ alignments of a sample position with respect to the AFM tip, and the laser beam position with respect to the cantilever and

Jhinhwan Lee; Jungseok Chae; Chung Koo Kim; Hyunjin Kim; Seungeun Oh; Young Kuk

2005-01-01

79

Indirect blood pressure measuring device  

NASA Technical Reports Server (NTRS)

Design and performance of a blood pressure recording device for pediatric use are reported. A strain gage transducer with a copper-beryllium strip as force sensing element is used to monitor skin movements and to convert them into electrical signals proportional to those displacements. Experimental tests with this device in recording of force developed above the left femoral artery of a dog accurately produced a blood pressure curve.

Hum, L.; Cole, C. E.

1973-01-01

80

Flow rate measuring devices for gas flows  

NASA Astrophysics Data System (ADS)

Flowrate measuring devices are described: volume meter with fixed or mobile walls; turbine meter; throttling procedure; ultrasonic and Doppler methods; vortex method; rotary flowmeter; and swinging body flow measuring procedure. Flowrate can also be measured from the force exerted on bodies immersed in a fluid or based on thermodynamical principles. The characteristics and operating envelope of each device/method are given.

Bonfig, K. W.

1985-07-01

81

Ambulatory device for measuring urine flow  

US Patent & Trademark Office Database

An ambulatory device for measuring urine flow comprises a portable hand-held container and a handgrip mounted thereto. A flow-measuring device is located in the container, and a means for collecting the data measured by the flow-measuring device is also provided. The parameters of the urine flow in the container are measured by the flow-measuring device and are processed by the aforementioned means for collecting data. The handgrip is pivotally mounted to the container by a double-pivot mechanism for maintaining the container substantially vertical in a number of positions of the handgrip. The flow-measuring device includes a sensor that measures a displacement of an air column related to a variation of pressure due to a variation of a urine level in the container.

2010-04-06

82

A Portable, High Resolution, Surface Measurement Device  

NASA Technical Reports Server (NTRS)

A high resolution, portable, surface measurement device has been demonstrated to provide micron-resolution topographical plots. This device was specifically developed to allow in-situ measurements of defects on the Space Shuttle Orbiter windows, but is versatile enough to be used on a wide variety of surfaces. This paper discusses the choice of an optical sensor and then the decisions required to convert a lab bench optical measurement device into an ergonomic portable system. The necessary trade-offs between performance and portability are presented along with a description of the device developed to measure Orbiter window defects.

Ihlefeld, Curtis M.; Burns, Bradley M.; Youngquist, Robert C.

2012-01-01

83

Raman temperature measurement  

NASA Astrophysics Data System (ADS)

We are examining the experimental trade-offs for the use of the spontaneous Raman Stokes/anti-Stokes intensity ratio as a fundamental temperature measurement at static and dynamic extreme conditions. The trade-off space includes spatial resolution and temperature range versus vibrational frequency, as well as heating of the sample and nonlinear damage caused by the excitation laser. The experiments are being performed under a range of experimental conditions from nanoseconds to seconds and from cryogenic (77 K) to elevated (ca. 1000 K) temperatures. The results are being compared to calculations for transparent metal oxide and polymer materials, with the aim to demonstrate their potential as temperature reporters when used as thin windows on opaque materials.

Moore, D. S.; McGrane, S. D.

2014-05-01

84

Device Measures Angle Of Deployment  

NASA Technical Reports Server (NTRS)

Simple electromechanical device indicates angular position of unfolding panel during and after deployment. Resistance of potentiometer gradually increases as unfolding of solar panel about hinge moves wiper of potentiometer. At full deployment, panel pushes and opens normally closed switch. Designed for use on panel of solar photovoltaic cells in spacecraft, modified for use in other, similar position-indicating applications.

Jermakian, Joel B.

1991-01-01

85

Characteristics of III-V Semiconductor Devices at High Temperature  

NASA Technical Reports Server (NTRS)

This paper presents the development of III-V based pseudomorphic high electron mobility transistors (PHEMT's) designed to operate over the temperature range 77 to 473 K (-196 to 200 C). These devices have a pseudomorphic undoped InGaAs channel that is sandwiched between an AlGaAs spacer and a buffer layer; gate widths of 200, 400, 1600, and 3200 micrometers; and a gate length of 2 micrometers. Measurements were performed at both room temperature and 473 K (200 C) and show that the drain current decreases by 30 percent and the gate current increases to about 9 microns A (at a reverse bias of -1.5 V) at the higher temperature. These devices have a maximum DC power dissipation of about 4.5 W and a breakdown voltage of about 16 V.

Simons, Rainee N.; Young, Paul G.; Taub, Susan R.; Alterovitz, Samuel A.

1994-01-01

86

Ambulatory blood pressure measuring devices.  

PubMed

During the last 6 years ABPM has become a widely used method in the diagnosis and treatment of hypertensive patients as well as in correlating the disease to prognosis. Up to January 1995, the international market offered 43 devices from 31 manufacturers. In Germany there are 18 devices available on the market from 10 different manufactures. Mainly, two different techniques are applied, ausculation and oscillometry, each having some advantages and disadvantages: The oscillometric technique may be preferable in patients with hyperkinetic circulation (e.g., pregnancy), with ausculatory gap and when surrounding noises are interfering, whereas the auscultatory technique, being the original method, has some advantages in patients with dysrhythmias and atrial fibrillation, as well as in dynamic (bicycle) exercise. The auscultatory method may be optimized by using ECG-, respectively oscillometric gating. The future development, which has already been realized in seven international recorders, offers the opportunity of either using auscultatory and/or oscillometric techniques during the same recording. To estimate the "true" sleeping interval more precisely a "day-night-button" at the recorder side is helpful. Furthermore, an uniform computer printout of the mean values of day- and night-time intervals, together with the widely approved limits of normotension should be achieved; last, but not least, an important factor for the widespread use of ABPM in general practice, as well as in the hospital, will be the prices of the recorders. Which have been reduced to about DM 3000-6000 in Germany (January 1996). PMID:8896297

Krnig, B

1996-01-01

87

Design parameter evaluation of a metal recoated Fiber Bragg Grating sensors for measurement of cryogenic temperature or stress in superconducting devices  

NASA Astrophysics Data System (ADS)

There are plenty of complex physical phenomena which remain to be studied and verified experimentally for building an optimized superconducting magnet. The main problem for experimental validations is due to the unavailability of suitable sensors. This paper proposes a Fiber Bragg Gratings (FBG) sensor for this purpose which allows access to the local temperature/stress state. To measure the low temperature (20 K), FBG can be recoated with materials having high thermal expansion coefficient (HTCE). This can induce a thermal stress for a temperature change, which in turn increases the sensitivity of the sensor. The performance of such sensors has been experimentally studied and reported in earlier paper [Rajinikumar R, Suesser M, Narayankhedkar KG, Krieg G, Atrey MD. Performance evaluation of metallic coated Fiber Bragg Grating sensors for sensing cryogenic temperature. Cryogenics 2008;48:142-7]. This paper aims at evaluation and determination of different design parameters like coating materials, coating thickness, grating period and the grating length for design of better performance FBG sensor for low temperature/stress measurements.

Rajinikumar, R.; Ser, M.; Narayankhedkar, K. G.; Krieg, G.; Atrey, M. D.

2009-05-01

88

Device and method for detecting sulfur dioxide at high temperatures  

DOEpatents

The present invention relates to a method for selectively detecting and/or measuring gaseous SO.sub.2 at a temperature of at least 500.degree. C., the method involving: (i) providing a SO.sub.2-detecting device including an oxygen ion-conducting substrate having on its surface at least three electrodes comprising a first, second, and third electrode; (ii) driving a starting current of specified magnitude and temporal variation between the first and second electrodes; (iii) contacting the SO.sub.2-detecting device with the SO.sub.2-containing sample while maintaining the magnitude and any temporal variation of the starting current, wherein said SO.sub.2-containing sample causes a change in the electrical conductance of said device; and (iv) detecting the change in electrical conductance of the device based on measuring an electrical property related to or indicative of the conductance of the device between the first and third electrodes, or between the second and third electrodes, and detecting SO.sub.2 in the SO.sub.2-containing sample based on the measured change in electrical conductance.

West, David L. (Oak Ridge, TN); Montgomery, Frederick C. (Oak Ridge, TN); Armstrong, Timothy R. (Clinton, TN)

2011-11-01

89

PORTABLE DEVICE FOR MEASURING SEDIMENT RESUSPENSION  

EPA Science Inventory

A portable device for measuring sediment resuspension has been developed. he device consists of a cylindrical chamber inside of which a horizontal grid oscillates vertically. he sediments whose properties are to be determined are placed at the bottom of the chamber with water ove...

90

Simple device measures solar radiation  

NASA Technical Reports Server (NTRS)

Simple inexpensive thermometer, insolated from surroundings by transparent glass or plastic encasement, measures intensities of solar radiation, or radiation from other sources such as furnaces or ovens. Unit can be further modified to accomplish readings from remote locations.

Humphries, W. R.

1977-01-01

91

Portable Device Measures Perpendicularity Of Threaded Hole  

NASA Technical Reports Server (NTRS)

Simple portable device gives quantitative information on amount by which axis of threaded hole in workpiece deviates from perpendicularity to adjacent exterior surface of workpiece. Measurements made easily in factory, shop, or field.

Scarpelli, August R.; Buttler, Daniel W.

1995-01-01

92

Device for measurement of corrosiveness of smoke  

US Patent & Trademark Office Database

A device for measuring the corrosiveness of smoke, comprising a chamber, means for creating in the chamber an atmosphere of air of predetermined humitidy, heating means for heating the said atmosphere and walls of the chamber to a predetermined temperature, means for causing the combustion of a sample of material in the chamber, water circulation cooling means for condensing the smoke and products of pyrolysis generated by the said combustion onto a resistive metallic element exposed inside the chamber, the measurement of the corrosiveness of the smoke being carried out by measuring the variation in electrical resistance of the said element. The chamber comprises: a cylinder of methyl polymethacrylate open at its two ends; two thermally insulating end doors, constituted by an assembly of methyl polymethacrylate panels separated by interstitial air, and means for thermal insulation and gas-tightness between the doors and the cylinder, and heating means comprising a resistive metallic wire wound in a helix on the external periphery of the cylinder.

1988-12-06

93

Validity and Reliability of Devices That Assess Body Temperature During Indoor Exercise in the Heat  

PubMed Central

Context: When assessing exercise hyperthermia outdoors, the validity of certain commonly used body temperature measuring devices has been questioned. A controlled laboratory environment is generally less influenced by environmental factors (eg, ambient temperature, solar radiation, wind) than an outdoor setting. The validity of these temperature measuring devices in a controlled environment may be more acceptable. Objective: To assess the validity and reliability of commonly used temperature devices compared with rectal temperature in individuals exercising in a controlled, high environmental temperature indoor setting and then resting in a cool environment. Design: Time series study. Setting: Laboratory environmental chamber (temperature ?=? 36.4 1.2C [97.5 2.16F], relative humidity ?=? 52%) and cool laboratory (temperature ?=? approximately 23.3C [74.0F], relative humidity ?=? 40%). Patients or Other Participants: Fifteen males and 10 females. Intervention(s): Rectal, gastrointestinal, forehead, oral, aural, temporal, and axillary temperatures were measured with commonly used temperature devices. Temperature was measured before and 20 minutes after entering the environmental chamber, every 30 minutes during a 90-minute treadmill walk in the heat, and every 20 minutes during a 60-minute rest in mild conditions. Device validity and reliability were assessed with various statistical measures to compare the measurements using each device with rectal temperature. A device was considered invalid if the mean bias (average difference between rectal and device temperatures) was more than 0.27C (0.50F). Main Outcome Measure(s): Measured temperature from each device (mean and across time). Results: The following devices provided invalid estimates of rectal temperature: forehead sticker (0.29C [0.52F]), oral temperature using an inexpensive device (?1.13C [?2.03F]), temporal temperature measured according to the instruction manual (?0.87C [?1.56F]), temporal temperature using a modified technique (?0.63C [?1.13F]), oral temperature using an expensive device (?0.86C, [?1.55F]), aural temperature (?0.67C, [?1.20F]), axillary temperature using an inexpensive device (?1.25C, [?2.24F]), and axillary temperature using an expensive device (?0.94F [?1.70F]). Measurement of intestinal temperature (mean bias of ?0.02C [?0.03F]) was the only device considered valid. Devices measured in succession (intestinal, forehead, temporal, and aural) showed acceptable reliability (all had a mean bias ?=? 0.09C [0.16F] and r ? 0.94]). Conclusions: Even during laboratory exercise in a controlled environment, devices used to measure forehead, temporal, oral, aural, and axillary body sites did not provide valid estimates of rectal temperature. Only intestinal temperature measurement met the criterion. Therefore, we recommend that rectal or intestinal temperature be used to assess hyperthermia in individuals exercising indoors in the heat.

Ganio, Matthew S; Brown, Christopher M; Casa, Douglas J; Becker, Shannon M; Yeargin, Susan W; McDermott, Brendon P; Boots, Lindsay M; Boyd, Paul W; Armstrong, Lawrence E; Maresh, Carl M

2009-01-01

94

Going Places No Infrared Temperature Devices Have Gone Before  

NASA Technical Reports Server (NTRS)

Exergen's IRt/c is a self-powered sensor that matches a thermocouple within specified temperature ranges and provides a predictable and repeatable signal outside of this specified range. Possessing an extremely fast time constant, the infrared technology allows users to measure product temperature without touching the product. The IRt/c uses a device called a thermopile to measure temperature and generate current. Traditionally, these devices are not available in a size that would be compatible with the Exergen IRt/c, based on NASA s quarterinch specifications. After going through five circuit designs to find a thermopile that would suit the IRt/c design and match the signal needed for output, Exergen maintains that it developed a model that totaled just 20 percent of the volume of the previous smallest detector in the world. Following completion of the project with Glenn, Exergen continued development of the IRt/c for other customers, spinning off a new product line called the micro IRt/c. This latest development has broadened applications for industries that previously could not use infrared thermometers due to size constraints. The first commercial use of the micro IRt/c involved an original equipment manufacturer that makes laminating machinery consisting of heated rollers in very tight spots. Accurate temperature measurement for this application requires close proximity to the heated rollers. With the micro IRt/c s 50-millisecond time constant, the manufacturer is able to gain closer access to the intended temperature targets for exact readings, thereby increasing productivity and staying ahead of competition.In a separate application, the infrared temperature sensor is being utilized for avalanche warnings in Switzerland. The IRt/c is mounted about 5 meters above the ground to measure the snow cover throughout the mountainous regions of the country.

2003-01-01

95

Wireless device for monitoring the temperature - moisture regime in situ  

NASA Astrophysics Data System (ADS)

This contribution presents the wireless device for monitoring the temperature - moisture regime in situ. For the monitoring so called moisture sensor is used. Principle of moisture sensor is based on measuring the thermal conductivity. Moisture sensor has cylindrical shape with about 20 mm diameter and 20 mm length. It is made of porous material identical to the monitored object. The thermal conductivity is measured by hot-ball method. Hot-ball method is patented invention of the Institute of Physic SAS. It utilizes a small ball, diameter up to 2 mm, in which sensing elements are incorporated. The ball produces heat spreading into surrounding material, in our case into body of the moisture sensor. Temperature of the ball is measured simultaneously. Then change of the temperature, in steady state, is inversely proportional to the thermal conductivity. Such moisture sensor is inserted into monitored wall. Thermophysical properties of porous material are function of moisture. Moisture sensors are calibrated for dry and water saturated state. Whole the system is primarily intended to do long-term monitoring. Design of a new electronic device was needed for this innovative method. It covers all needed operations for measurement. For example energizing hot-ball sensor, measuring its response, storing the measured data and wireless data transmission. The unit is able to set parameters of measurement via wireless access as well. This contribution also includes the description of construction and another features of the wireless measurement system dedicated for this task. Possibilities and functionality of the system is demonstrated by actual monitoring of the tower of St. Martin's Cathedral in Bratislava. Correlations with surrounding meteorological conditions are presented. Some of them can be also measured by our system, right in the monitoring place.

Hudec, Jn; tofanik, Vladimr; Vretenr, Viliam; Kubi?r, ?udovt

2014-05-01

96

Multiple local probe measuring device and method  

US Patent & Trademark Office Database

The invention provides a local probe measuring device for effecting local measurements refering to a sample, comprising a plurality of local probes for local measurements with respect to a sample or a reference surface, a measurement condition adjustment arrangement adapted to commonly adjust measurement conditions of said local probes with respect to the sample or the reference surface, a plurality of detection arrangements, each being associated or adapted to be associated to one particular of said local probes and adapted to independently detect measurement data refering to local measurements effected by said particular local probe. Further, methods for effecting local measurements and local manipulations by means of multiple local probes are provided.

2003-06-24

97

Electrolyte measurement device and measurement procedure  

DOEpatents

A method and apparatus for measuring the through-thickness resistance or conductance of a thin electrolyte is provided. The method and apparatus includes positioning a first source electrode on a first side of an electrolyte to be tested, positioning a second source electrode on a second side of the electrolyte, positioning a first sense electrode on the second side of the electrolyte, and positioning a second sense electrode on the first side of the electrolyte. current is then passed between the first and second source electrodes and the voltage between the first and second sense electrodes is measured.

Cooper, Kevin R. (Southern Pines, NC); Scribner, Louie L. (Southern Pines, NC)

2010-01-26

98

Development of a Force Measurement Device.  

National Technical Information Service (NTIS)

The development of a Force Measurement Device (FMD) for recording interface forces between shaker table and Ariane 4 satellites is reported. The FMD is designed to measure forces and moments in the frequency range from 0.1 to 100 Hz with an accuracy bette...

O. Wilmar

1991-01-01

99

Skin Friction Measuring Device for Aircraft.  

National Technical Information Service (NTIS)

A skin friction measuring device for measuring the resistance of an aerodynamic surface to an airstream is disclosed. It is characterized by a friction plate adapted to be disposed in a flush relationship with the external surface of the aircraft and be d...

D. R. Bellman L. C. Montoya

1979-01-01

100

An Innovative Flow-Measuring Device: Thermocouple Boundary Layer Rake  

NASA Technical Reports Server (NTRS)

An innovative flow-measuring device, a thermocouple boundary layer rake, was developed. The sensor detects the flow by using a thin-film thermocouple (TC) array to measure the temperature difference across a heater strip. The heater and TC arrays are microfabricated on a constant-thickness quartz strut with low heat conductivity. The device can measure the velocity profile well into the boundary layer, about 65 gm from the surface, which is almost four times closer to the surface than has been possible with the previously used total pressure tube.

Hwang, Danny P.; Fralick, Gustave C.; Martin, Lisa C.; Wrbanek, John D.; Blaha, Charles A.

2001-01-01

101

A liquid bath for accurate temperature measurements  

Microsoft Academic Search

At the Thermometric division of the Italian Institute of Metrology (IMGC) a new liquid oil bath has been designed, manufactured and characterized with the aim to provide a suitable device for thermometers calibrations at the millikelvin level in the range from ?10C to 100C. The temperature of the bath in the measuring zone is stable within a few tenths of

Andrea Merlone; Luigi Iacomini; Antonio Tiziani; Piero Marcarino

2007-01-01

102

21 CFR 882.1550 - Nerve conduction velocity measurement device.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Nerve conduction velocity measurement device. 882.1550... § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device is a...

2013-04-01

103

21 CFR 882.1550 - Nerve conduction velocity measurement device.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Nerve conduction velocity measurement device...Neurological Diagnostic Devices § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement...

2009-04-01

104

21 CFR 882.1550 - Nerve conduction velocity measurement device.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Nerve conduction velocity measurement device...Neurological Diagnostic Devices § 882.1550 Nerve conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement...

2010-04-01

105

21 CFR 886.4280 - Intraocular pressure measuring device.  

Code of Federal Regulations, 2010 CFR

... § 886.4280 Intraocular pressure measuring device. (a) Identification. An intraocular pressure measuring device is a manual or AC-powered device intended to measure intraocular pressure. Also included are any...

2010-04-01

106

21 CFR 886.4280 - Intraocular pressure measuring device.  

Code of Federal Regulations, 2013 CFR

... § 886.4280 Intraocular pressure measuring device. (a) Identification. An intraocular pressure measuring device is a manual or AC-powered device intended to measure intraocular pressure. Also included are any...

2013-04-01

107

Measurement-Device-Independent Quantum Key Distribution  

NASA Astrophysics Data System (ADS)

How to remove detector side channel attacks has been a notoriously hard problem in quantum cryptography. Here, we propose a simple solution to this problemmeasurement-device-independent quantum key distribution (QKD). It not only removes all detector side channels, but also doubles the secure distance with conventional lasers. Our proposal can be implemented with standard optical components with low detection efficiency and highly lossy channels. In contrast to the previous solution of full device independent QKD, the realization of our idea does not require detectors of near unity detection efficiency in combination with a qubit amplifier (based on teleportation) or a quantum nondemolition measurement of the number of photons in a pulse. Furthermore, its key generation rate is many orders of magnitude higher than that based on full device independent QKD. The results show that long-distance quantum cryptography over say 200 km will remain secure even with seriously flawed detectors.

Lo, Hoi-Kwong; Curty, Marcos; Qi, Bing

2012-03-01

108

Measurement-device-independent quantum key distribution.  

PubMed

How to remove detector side channel attacks has been a notoriously hard problem in quantum cryptography. Here, we propose a simple solution to this problem--measurement-device-independent quantum key distribution (QKD). It not only removes all detector side channels, but also doubles the secure distance with conventional lasers. Our proposal can be implemented with standard optical components with low detection efficiency and highly lossy channels. In contrast to the previous solution of full device independent QKD, the realization of our idea does not require detectors of near unity detection efficiency in combination with a qubit amplifier (based on teleportation) or a quantum nondemolition measurement of the number of photons in a pulse. Furthermore, its key generation rate is many orders of magnitude higher than that based on full device independent QKD. The results show that long-distance quantum cryptography over say 200 km will remain secure even with seriously flawed detectors. PMID:22540686

Lo, Hoi-Kwong; Curty, Marcos; Qi, Bing

2012-03-30

109

Passive Hybrid MEMS for High-Temperature Telemetric Measurements  

Microsoft Academic Search

A contactless sensor represents an attractive solution for high-temperature measurements in harsh environments, where the use of cables is not suitable, and where the temperature values are beyond those permitted by active electronic circuits. Temperature sensors have a wide variety of applications in automated processes for temperature control and regulation. This paper describes a passive sensing device suitable for high-temperature

Daniele Marioli; Emilio Sardini; Mauro Serpelloni

2010-01-01

110

21 CFR 882.1560 - Skin potential measurement device.  

Code of Federal Regulations, 2010 CFR

...device. (a) Identification. A skin potential measurement device is a general diagnostic device used to measure skin voltage by means of surface skin electrodes. (b) Classification. Class II (performance...

2010-04-01

111

21 CFR 882.1560 - Skin potential measurement device.  

Code of Federal Regulations, 2010 CFR

...device. (a) Identification. A skin potential measurement device is a general diagnostic device used to measure skin voltage by means of surface skin electrodes. (b) Classification. Class II (performance...

2009-04-01

112

A New Device for Studying Low or Zero Frequency Mechanical Motion at Very Low Temperatures  

Microsoft Academic Search

We have developed a new floppy wire device for studying the motion through quantum fluids and solids at very low temperatures.\\u000a The device is particularly well suited for producing large amplitudes of motion, for measuring drag forces at low frequency,\\u000a and for studying zero frequency dynamics by measuring transient behavior. The device is very versatile and allows motion\\u000a to be

D. I. Bradley; M. J. Fear; S. N. Fisher; A. M. Gunault; R. P. Haley; C. R. Lawson; G. R. Pickett; R. Schanen; V. Tsepelin; P. Williams

2011-01-01

113

Force based displacement measurement in micromechanical devices  

SciTech Connect

We demonstrate how force detection methods based on atomic force microscopy can be used to measure displacement in micromechanical devices. We show the operation of a simple microfabricated accelerometer, the proof mass of which incorporates a tip which can be moved towards an opposing surface. Both noncontact operation using long range electrostatic forces and tapping mode operation are demonstrated. The displacement sensitivity of the present device using feedback to control the tip-surface separation is approximately 1 nm. {copyright} 2001 American Institute of Physics.

O {close_quote}Shea, S. J.; Ng, C. K.; Tan, Y. Y.; Xu, Y.; Tay, E. H.; Chua, B. L.; Tien, N. C.; Tang, X. S.; Chen, W. T.

2001-06-18

114

Measuring Temperature: The Thermometer  

ERIC Educational Resources Information Center

The author discusses the historical development of the thermometer with the view of helping children understand the role that mathematics plays in society. A model thermometer that is divided into three sections, each displaying one of the three temperature scales used today (Fahrenheit, Celsius and Kelvin) is highlighted as a project to allow

Chamoun, Mirvette

2005-01-01

115

Thermal conductivity measurement of liquids in a microfluidic device  

Microsoft Academic Search

A new microfluidic-based approach to measuring liquid thermal conductivity is developed to address the requirement in many\\u000a practical applications for measurements using small (microlitre) sample size and integration into a compact device. The approach\\u000a also gives the possibility of high-throughput testing. A resistance heater and temperature sensor are incorporated into a\\u000a glass microfluidic chip to allow transmission and detection of

D. Kuvshinov; M. R. Bown; J. M. MacInnes; R. W. K. Allen; R. Ge; L. Aldous; C. Hardacre; N. Doy; M. I. Newton; G. McHale

2011-01-01

116

An evaluation of strain measuring devices for ceramic composites  

NASA Technical Reports Server (NTRS)

A series of tensile tests was conducted on SiC/reaction bonded silicon nitrides (RBSN) composites using different methods of strain measurement. The tests were used to find the optimum strain sensing device for use with continuous fiber reinforced ceramic matrix composites in ambient and high temperature environments. Bonded resistance gages were found to offer excellent performance for room temperature tests. The clip-on gage offers the same performance, but less time is required for mounting it to the specimen. Low contact force extensometers track the strain with acceptable results at high specimen temperatures. Silicon carbide rods with knife edges are preferred. The edges must be kept sharp. The strain measuring devices should be mounted on the flat side of the specimen. This is in contrast to mounting on the rough thickness side.

Gyekenyesi, John Z.; Bartolotta, Paul A.

1991-01-01

117

Enhanced Magnetostrictively Transduced SAW Devices - Measurements & Applications  

NASA Astrophysics Data System (ADS)

Surface acoustic wave (SAW) transducers can be made with magnetic materials using magnetostriction as a means of electromechanical coupling. Unlike conventional piezoelectrically transduced SAW devices, the magnetically transduced SAWs do not require an exotic single-crystal substrate or high temperature processing, and therefore may be easily integrated into Si-based integrated circuits. These devices have many potential applications, biosensors being one of the most promising. When the substrate between a transmitter and a detector transducer is functionalized with specific bio-receptors, a binding event will affect propagation of the SAW wave that can be detected with simple electronics. In previous MTSAW devices, the magnetomechanical coupling was found to be poor, resulting in insufficient signal amplitude. To obtain better performance, we are studying the use of alternative magnetostrictive materials including an amorphous CoFeTaZr alloy, CoNbZr, and compositions in the Terfernol family (TbFe2, etc.). We are using combinatorial materials science (continuous composition spread approach) to identify optimum alloy compositions. The devices are also being redesigned to yield better performance.

Woo, Noble C.

2005-03-01

118

Temperature Measurements in the Magnetic Measurement Facility  

SciTech Connect

Several key LCLS undulator parameter values depend strongly on temperature primarily because of the permanent magnet material the undulators are constructed with. The undulators will be tuned to have specific parameter values in the Magnetic Measurement Facility (MMF). Consequently, it is necessary for the temperature of the MMF to remain fairly constant. Requirements on undulator temperature have been established. When in use, the undulator temperature will be in the range 20.0 {+-} 0.2 C. In the MMF, the undulator tuning will be done at 20.0 {+-} 0.1 C. For special studies, the MMF temperature set point can be changed to a value between 18 C and 23 C with stability of {+-}0.1 C. In order to ensure that the MMF temperature requirements are met, the MMF must have a system to measure temperatures. The accuracy of the MMF temperature measurement system must be better than the {+-}0.1 C undulator tuning temperature tolerance, and is taken to be {+-}0.01 C. The temperature measurement system for the MMF is under construction. It is similar to a prototype system we built two years ago in the Sector 10 alignment lab at SLAC. At that time, our goal was to measure the lab temperature to {+-}0.1 C. The system has worked well for two years and has maintained its accuracy. For the MMF system, we propose better sensors and a more extensive calibration program to achieve the factor of 10 increase in accuracy. In this note we describe the measurement system under construction. We motivate our choice of system components and give an overview of the system. Most of the software for the system has been written and will be discussed. We discuss error sources in temperature measurements and show how these errors have been dealt with. The calibration system is described in detail. All the LCLS undulators must be tuned in the Magnetic Measurement Facility at the same temperature to within {+-}0.1 C. In order to ensure this, we are building a system to measure the temperature of the undulators to {+-}0.01 C. This note describes the temperature measurement system under construction.

Wolf, Zachary

2010-12-13

119

Optimization of a Fluidic Temperature Control Device.  

National Technical Information Service (NTIS)

Refinements are described to an existing fluidic temperature control system developed under a prior study which modulated temperature at the inlet to the liquid-cooled garment by using existing liquid supply and return lines to transmit signals to a fluid...

D. R. Rask J. B. Starr J. M. Zabsky

1970-01-01

120

High-Sensitivity Temperature Measurement  

ERIC Educational Resources Information Center

Describes a method of measuring small temperature differences that amount to a .01K, using an arrangement of a copper-constantan thermocouple, a microamplifier and a galvanometer, as an indirect way of measuring heat energy. (GA)

Leadstone, G. S.

1978-01-01

121

Precision of Four Acoustic Bone Measurement Devices  

NASA Technical Reports Server (NTRS)

Though many studies have quantified the precision of various acoustic bone measurement devices, it is difficult to directly compare the results among the studies, because they used disparate subject pools, did not specify the estimation methodology, or did not use consistent definitions for various precision characteristics. In this study, we used a repeated measures design protocol to directly determine the precision characteristics of four acoustic bone measurement devices: the Mechanical Response Tissue Analyzer (MRTA), the UBA-575+, the SoundScan 2000 (S2000), and the Sahara Ultrasound Bone Analyzer. Ten men and ten women were scanned on all four devices by two different operators at five discrete time points: Week 1, Week 2, Week 3, Month 3 and Month 6. The percent coefficient of variation (%CV) and standardized coefficient of variation were computed for the following precision characteristics: interoperator effect, operator-subject interaction, short-term error variance, and long-term drift. The MRTA had high interoperator errors for its ulnar and tibial stiffness measures and a large long-term drift in its tibial stiffness measurement. The UBA-575+ exhibited large short-term error variances and long-term drift for all three of its measurements. The S2000's tibial speed of sound measurement showed a high short-term error variance and a significant operator-subject interaction but very good values (less than 1%) for the other precision characteristics. The Sahara seemed to have the best overall performance, but was hampered by a large %CV for short-term error variance in its broadband ultrasound attenuation measure.

Miller, Christopher; Rianon, Nahid; Feiveson, Alan; Shackelford, Linda; LeBlanc, Adrian

2000-01-01

122

Precision of Four Acoustic Bone Measurement Devices  

NASA Technical Reports Server (NTRS)

Though many studies have quantified the precision of various acoustic bone measurement devices, it is difficult to directly compare the results among the studies, because they used disparate subject pools, did not specify the estimation methodology, or did not use consistent definitions for various precision characteristics. In this study, we used a repeated measures design protocol to directly determine the precision characteristics of four acoustic bone measurement devices: the Mechanical Response Tissue Analyzer (MRTA), the UBA-575+, the SoundScan 2000 (S2000), and the Sahara Ultrasound Done Analyzer. Ten men and ten women were scanned on all four devices by two different operators at five discrete time points: Week 1, Week 2, Week 3, Month 3 and Month 6. The percent coefficient of variation (%CV) and standardized coefficient of variation were computed for the following precision characteristics: interoperator effect, operator-subject interaction, short-term error variance, and long-term drift, The MRTA had high interoperator errors for its ulnar and tibial stiffness measures and a large long-term drift in its tibial stiffness measurement. The UBA-575+ exhibited large short-term error variances and long-term drift for all three of its measurements. The S2000's tibial speed of sound measurement showed a high short-term error variance and a significant operator-subject interaction but very good values ( < 1%) for the other precision characteristics. The Sahara seemed to have the best overall performance, but was hampered by a large %CV for short-term error variance in its broadband ultrasound attenuation measure.

Miller, Christopher; Feiveson, Alan H.; Shackelford, Linda; Rianon, Nahida; LeBlanc, Adrian

2000-01-01

123

Acoustical Measurement Of Furnace Temperatures  

NASA Technical Reports Server (NTRS)

Simple probes withstand severe conditions, yet give spatially-resolved temperature readings. Prototype acoustical system developed to measure temperatures from ambient to 1,800 degree F in such structures as large industrial lime kilns and recovery-boiler furnaces. Pulses of sound reflected from obstructions in sensing tube. Speed of sound and temperature in each segment deduced from travel times of pulses.

Parthasarathy, Shakkottai; Venkateshan, Shakkottai P.

1989-01-01

124

Magnetic measurements on insertion devices at NSLS  

Microsoft Academic Search

Magnetic measurements on three insertion devices for use in the NSLS x-ray ring are described. Hall probes were used for field mapping, and rotating long coils were used to determine integrated multipole coefficients. Results are presented for an iron pole-REC hybrid undulator, a vanadium permendur pole-REC wiggler and a 5 Tesla superconducting wiggler. 6 refs., 8 figs., 2 tabs.

G. Decker; J. Galayda; M. Kitamura; L. Solomon

1988-01-01

125

Device Application of High Temperature Superconductors.  

National Technical Information Service (NTIS)

Superconducting cylindrical films of niobium with superconducting transition temperatures Tc of about 9K and of niobium nitride with Tc of about 10K were prepared by dc sputtering procedures. A sputter etch technique was developed to sculpture into these ...

M. Nisenoff

1972-01-01

126

Temperature measurements of falling droplets  

SciTech Connect

The temperature of 225-{mu}m-dia decane droplets, which have fallen 100 mm through a hot quiescent, oxygen-free environment, has been measured using exciplex fluorescence thermometry. The droplets were doped with pyrene, and the relative intensities of pyrene monomer and excimer emissions were used to determine the droplet temperatures. The droplet temperature increases approximately 0.4C per C increase in the ambient temperature up to an ambient temperature of 200C. Less than 10% evaporation was observed for the droplets at the highest ambient temperatures.

Wells, M.R.; Melton, L.A. (Univ. of Texas, Richardson (USA))

1990-11-01

127

The blocking leakage current of packaged silicon devices after their storage at 250 C ambient temperature  

Microsoft Academic Search

Samples of commercial packaged silicon devices (diodes, thyristors, power MOSFETs) have been stored at 250degC ambient temperature for durations of 4 up to 100 hours. Comparisons of electrical characteristics measured before and after storage at this temperature revealed significant change in the level of the blocking leakage current for PN junctions with organic material passivation. The measured electrical characteristics with

Vasile V. N. Obreja

2008-01-01

128

Noise parameter measurement of microwave transistors at cryogenic temperature  

Microsoft Academic Search

A major drawback of active two-port microwave noise parameter measurement, by means of the multiple impedance technique at cryogenic temperature, lies in that a nonnegligible part of a lossy transmission line featuring a nonuniform temperature must be inserted between the automatic tuner (operated at room temperature) and the device input. Since the temperature distribution over that line is not precisely

Laurent Escotte; F. Sejalon; J. Graffeuil

1994-01-01

129

Skin friction measuring device for aircraft  

NASA Technical Reports Server (NTRS)

A skin friction measuring device for measuring the resistance of an aerodynamic surface to an airstream is described. It was adapted to be mounted on an aircraft and is characterized by a friction plate adapted to be disposed in a flush relationship with the external surface of the aircraft and be displaced in response to skin friction drag. As an airstream is caused to flow over the surface, a potentiometer connected to the plate for providing an electrical output indicates the magnitude of the drag.

Montoya, L. C.; Bellman, D. R. (inventors)

1980-01-01

130

Measuring charge nonuniformity in MOS devices  

NASA Technical Reports Server (NTRS)

Convenient method of determining inherent lateral charge non-uniformities along silicon dioxide/silicon interface of metal-oxide-semiconductor (MOS) employs rapid measurement of capacitance of interface as function of voltage at liquid nitrogen temperature. Charge distribution is extracted by fast-Fourier-transform analysis of capacitance voltage (C-V) measurement.

Maserjian, J.; Zamani, N.

1980-01-01

131

Noncontact true temperature measurement, 2  

NASA Technical Reports Server (NTRS)

A laser pyrometer was developed for acquiring the true temperature of a levitated sample. The reflectivity is measured by first expanding the laser beam to cover the entire cross-sectional surface of the diffuse target. The reflectivity calibration of this system is determined from the surface emissivity of a target with a blackbody cavity. The emissivity of the real target can then be calculated. The overall system constant is obtained by passively measuring the radiance of the blackbody cavity (emissivity = 1.0) at a known, arbitrary temperature. Since the photosensor used is highly linear over the entire operating temperature range, the true temperature of the target can then be computed. The latest results available from this on-going research indicate that true temperatures thus obtained are in very good quantitative agreement with thermocouple measured temperatures.

Lee, Mark C.; Allen, James L.

1988-01-01

132

Electrical performance of semiconductor devices at cryogenic temperatures  

NASA Technical Reports Server (NTRS)

The electrical performance of semiconductor devices is examined over the temperature range from 300 to 1.4K The design, fabrication, and testing of p-channel field effective transistors (MOSFET) are emphasized to develop a device that will perform satisfactorily in the temperature range from 4.2 to 1.4K. The current-voltage characteristics of the device are obtained as a function of temperature for varying channel lengths and channel dopant levels. The MOSFET's with average channel lengths of 3.27, 5.68, 8.37, and 11.39 microns are examined. It is indicated that the devices with the shorter channel lengths perform better in the 4 to 20K range than those with the longer channel lengths.

Ventrice, C. A.

1985-01-01

133

Amorphous metallizations for high-temperature semiconductor device applications  

NASA Technical Reports Server (NTRS)

The initial results of work on a class of semiconductor metallizations which appear to hold promise as primary metallizations and diffusion barriers for high temperature device applications are presented. These metallizations consist of sputter-deposited films of high T sub g amorphous-metal alloys which (primarily because of the absence of grain boundaries) exhibit exceptionally good corrosion-resistance and low diffusion coefficients. Amorphous films of the alloys Ni-Nb, Ni-Mo, W-Si, and Mo-Si were deposited on Si, GaAs, GaP, and various insulating substrates. The films adhere extremely well to the substrates and remain amorphous during thermal cycling to at least 500 C. Rutherford backscattering and Auger electron spectroscopy measurements indicate atomic diffussivities in the 10 to the -19th power sq cm/S range at 450 C.

Wiley, J. D.; Perepezko, J. H.; Nordman, J. E.; Kang-Jin, G.

1981-01-01

134

Validity of Devices That Assess Body Temperature During Outdoor Exercise in the Heat  

PubMed Central

Context: Rectal temperature is recommended by the National Athletic Trainers' Association as the criterion standard for recognizing exertional heat stroke, but other body sites commonly are used to measure temperature. Few authors have assessed the validity of the thermometers that measure body temperature at these sites in athletic settings. Objective: To assess the validity of commonly used temperature devices at various body sites during outdoor exercise in the heat. Design: Observational field study. Setting: Outdoor athletic facilities. Patients or Other Participants: Fifteen men and 10 women (age = 26.5 5.3 years, height = 174.3 11.1 cm, mass = 72.73 15.95 kg, body fat = 16.2 5.5%). Intervention(s): We simultaneously tested inexpensive and expensive devices orally and in the axillary region, along with measures of aural, gastrointestinal, forehead, temporal, and rectal temperatures. Temporal temperature was measured according to the instruction manual and a modified method observed in medical tents at local road races. We also measured forehead temperatures directly on the athletic field (other measures occurred in a covered pavilion) where solar radiation was greater. Rectal temperature was the criterion standard used to assess the validity of all other devices. Subjects' temperatures were measured before exercise, every 60 minutes during 180 minutes of exercise, and every 20 minutes for 60 minutes of postexercise recovery. Temperature devices were considered invalid if the mean bias (average difference between rectal temperature and device temperature) was greater than 0.27C (0.5F). Main Outcome Measure(s): Temperature from each device at each site and time point. Results: Mean bias for the following temperatures was greater than the allowed limit of 0.27C (0.5F): temperature obtained via expensive oral device (?1.20C [?2.17F]), inexpensive oral device (?1.67C [?3.00F]), expensive axillary device (?2.58C [?4.65F]), inexpensive axillary device (?2.07C [?3.73F]), aural method (?1.00C [?1.80F]), temporal method according to instruction manual (?1.46C [?2.64F]), modified temporal method (?1.36C [?2.44F]), and forehead temperature on the athletic field (0.60C [1.08F]). Mean bias for gastrointestinal temperature (?0.19C [?0.34F]) and forehead temperature in the pavillion (?0.14C [?0.25F]) was less than the allowed limit of 0.27C (0.5F). Forehead temperature depended on the setting in which it was measured and showed greater variation than other temperatures. Conclusions: Compared with rectal temperature (the criterion standard), gastrointestinal temperature was the only measurement that accurately assessed core body temperature. Oral, axillary, aural, temporal, and field forehead temperatures were significantly different from rectal temperature and, therefore, are considered invalid for assessing hyperthermia in individuals exercising outdoors in the heat.

Casa, Douglas J; Becker, Shannon M; Ganio, Matthew S; Brown, Christopher M; Yeargin, Susan W; Roti, Melissa W; Siegler, Jason; Blowers, Julie A; Glaviano, Neal R; Huggins, Robert A; Armstrong, Lawrence E; Maresh, Carl M

2007-01-01

135

An unheated permeation device for calibrating atmospheric VOC measurements  

NASA Astrophysics Data System (ADS)

The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs) is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as on board aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, so that the instantaneous permeation rate can be ascribed to a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i) a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii) a water bath as heat buffer, and (iii) a vacuum-panel based insulation, in which features (ii) and (iii) minimize temperature drifts to ~30 mK h-1 per Kelvin temperature difference to the environment. The respective uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1%. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 ?m) dominates.

Brito, J.; Zahn, A.

2011-10-01

136

Devices for flow measurement and control -- 1993  

SciTech Connect

This conference focuses on a small aspect of technological progress, specifically on the devices for flow measurement and control. Papers have been contributed from industry, academia, and government, providing a very broad view of the state of the art and needs for improvement of research. The number of international contributions at this symposium is particularly gratifying to the organizers. There are authors from Great Britain, France, Norway, Germany, and Korea as well as from the US. This implies that flow measurement and control is a topic of significant interest to the international community. It is the editors hope that this symposium volume will serve as a reference for future exchange of ideas and as a catalyst for furthering the state of the art of flow measurement and control. Papers have been processed separately for inclusion on the data base.

Blechinger, C.J. (ed.) (Ford Motor Co., Dearborn, MI (United States)); Sherif, S.A. (ed.) (Univ. of Florida, Gainesville, FL (United States))

1993-01-01

137

Colloidal-gold electrosensor measuring device  

DOEpatents

The present invention provides a new device for use in measuring lead levels in biological and environmental samples. Using square wave coulometry and colloidal gold particles impregnated on carbon electrodes, the present invention provides a rapid, reliable, portable and inexpensive means of detecting low lead levels. The colloidal gold modified electrodes have microelectrode array characteristics and produce significantly higher stripping detection signals for lead than are produced at bulk gold electrode surfaces. The method is effective in determining levels of lead down to at least 5 {micro}g/dL in blood samples as small as 10 {micro}L. 9 figs.

Wegner, S.; Harpold, M.A.; McCaffrey, T.M.; Morris, S.E.; Wojciechowski, M.; Zhao, J.; Henkens, R.W.; Naser, N.; O`Daly, J.P.

1995-11-21

138

Colloidal-gold electrosensor measuring device  

DOEpatents

The present invention provides a new device for use in measuring lead levels in biological and environmental samples. Using square wave coulometry and colloidal gold particles impregnated on carbon electrodes, the present invention provides a rapid, reliable, portable and inexpensive means of detecting low lead levels. The colloidal gold modified electrodes have microelectrode array characteristics and produce significantly higher stripping detection signals for lead than are produced at bulk gold electrode surfaces. The method is effective in determining levels of lead down to at least 5 .mu.g/dL in blood samples as small as 10 .mu.L.

Wegner, Steven (Chapel Hill, NC); Harpold, Michael A. (Durham, NC); McCaffrey, Terence M. (Durham, NC); Morris, Susan E. (Chapel Hill, NC); Wojciechowski, Marek (Cary, NC); Zhao, Junguo (Chapel Hill, NC); Henkens, Robert W. (Durham, NC); Naser, Najih (Durham, NC); O'Daly, John P. (Carrboro, NC)

1995-01-01

139

Integrated Emissivity And Temperature Measurement  

DOEpatents

A multi-channel spectrometer and a light source are used to measure both the emitted and the reflected light from a surface which is at an elevated temperature relative to its environment. In a first method, the temperature of the surface and emissivity in each wavelength is calculated from a knowledge of the spectrum and the measurement of the incident and reflected light. In the second method, the reflected light is measured from a reference surface having a known reflectivity and the same geometry as the surface of interest and the emitted and the reflected light are measured for the surface of interest. These measurements permit the computation of the emissivity in each channel of the spectrometer and the temperature of the surface of interest.

Poulsen, Peter (Livermore, CA)

2005-11-08

140

Non-contact temperature measurement  

NASA Astrophysics Data System (ADS)

Three methods for noncontact temperature measurement are presented. Ideal gas thermometry is realized by using laser-induced fluorescence to measure the concentration of mercury atoms in a Hg-Ar mixture in the vicinity of hot specimens. Emission polarimetry is investigated by measuring the spatially resolved intensities of polarized light from a hot tungsten sphere. Laser polarimetry is used to measure the optical properties, emissivity, and, in combination with optical pyrometry, the temperature of electromagnetically levitated liquid aluminum. The precision of temperature measurements based on the ideal gas law is + or - 2.6 percent at 1500-2000 K. The polarized emission technique is found to have the capability to determine optical properties and/or spectral emissivities of specimens over a wide range of wavelengths with quite simple instruments.

Nordine, Paul C.; Krishnan, Shankar; Weber, J. K. R.; Schiffman, Robert A.

141

Containerless high temperature property measurements  

NASA Technical Reports Server (NTRS)

Containerless processing in the low gravity environment of space provides the opportunity to increase the temperature at which well controlled processing of and property measurements on materials is possible. This project was directed towards advancing containerless processing and property measurement techniques for application to materials research at high temperatures in space. Containerless high temperature material property studies include measurements of the vapor pressure, melting temperature, optical properties, and spectral emissivities of solid boron. The reaction of boron with nitrogen was also studied by laser polarimetric measurement of boron nitride film growth. The optical properties and spectral emissivities were measured for solid and liquid silicon, niobium, and zirconium; liquid aluminum and titanium; and liquid Ti-Al alloys of 5 to 60 atomic pct. titanium. Alternative means for noncontact temperature measurement in the absence of material emissivity data were evaluated. Also, the application of laser induced fluorescence for component activity measurements in electromagnetic levitated liquids was studied, along with the feasibility of a hybrid aerodynamic electromagnetic levitation technique.

Nordine, Paul C.; Weber, J. K. Richard; Krishnan, Shankar; Anderson, Collin D.

1991-01-01

142

Current status of low-temperature radiator thermophotovoltaic devices  

SciTech Connect

The current performance status of low-temperature radiator (< 1,000 C) thermophotovoltaic (TPV) devices is presented. For low-temperature radiators, both power density and efficiency are equally important in designing an effective TPV system. Comparisons of 1 cm x 1 cm, 0.55 eV InGaAs and InGaAsSb voltaic devices are presented. Currently, InGaAs lattice-mismatched devices offer superior performance in comparison to InGaAsSb lattice-matched devices, due to the former`s long-term development for numerous optoelectronic applications. However, lattice-matched antimony-based quaternaries offer numerous potential advantages.

Charache, G.W.; Egley, J.L.; Danielson, L.R.; DePoy, D.M.; Baldasaro, P.F.; Campbell, B.C. [Lockheed Martin Inc., Schenectady, NY (United States); Hui, S.; Fraas, L.M. [JX-Crystals Inc., Issaquah, WA (United States); Wojtczuk, S.J. [SPIRE Corp., Bedford, MA (United States)

1996-05-01

143

High-Temperature Probe Station Developed to Characterize Microwave Devices Through 500 C  

NASA Technical Reports Server (NTRS)

A photograph and a block diagram of the high-temperature probe station are shown. The system consists of the ceramic heater mounted on a NASA shuttle tile insulator, a direct current power supply, a personal-computer-based data acquisition and temperature controller, microwave probes, a microscope, and a network analyzer. The ability to perform microwave tests at high temperatures is becoming necessary. There is now a need for sensors and communication circuits that can operate at 500 C and above for aircraft engine development and monitoring during flight. To address this need, researchers have fabricated devices using wide bandgap semiconductors such as SiC with targeted operating temperatures of 500 to 600 C. However, the microwave properties of these devices often change drastically with temperature, so any designs that are intended to be used in such an environment must be characterized at high temperatures. For some reliability, lifetime, and direct-current testing, the device under test can be packaged and characterized in an oven. However, for RF and microwave measurements, it is usually not possible to establish a calibrated reference plane at the device terminals within a package. In addition, the characteristics of the package would vary over a 500 C temperature range, and this would have to be accounted for when the data were analyzed. A high temperature probe station allows circuits and devices to be characterized through on wafer measurements across a broad temperature range with known reference plane. The conventional, commercially available thermal wafer-probe stations that are used to evaluate microwave devices across a controlled temperature range have a typical upper limit of 200 C. Standalone thermal heating chucks are available with an extended upper temperature range of 300 to 400 C. To effectively characterize devices at temperatures up to and surpassing 500 C, Glenn researchers developed a custom probe station. In the past, custom probe stations have been developed to test devices under other extreme environments, such as cryogenic temperatures as low as 37 K. Similarly, this custom probe station was specifically modified for high-temperature use. It allows devices to be measured quickly and flexibly, without the use of wire bonds and test fixtures. The probe station is shown making scattering parameter measurements from 1 to 50 GHz with a Hewlett-Packard 8510C Network Analyzer. There is a half-wafer of silicon directly on top of the heater to provide a uniform heated platform for our sample. A quarter wafer of silicon carbide forms the substrate for our test circuit of several transmission lines.

Downey, Alan N.; Schwartz, Zachary D.

2004-01-01

144

Silicon carbide and diamond for high temperature device applications  

Microsoft Academic Search

The physical and chemical properties of wide bandgap semiconductors silicon carbide and diamond make these materials an ideal\\u000a choice for device fabrication for applications in many different areas, e.g. light emitters, high temperature and high power\\u000a electronics, high power microwave devices, micro-electromechanical system (MEMS) technology, and substrates. These semiconductors\\u000a have been recognized for several decades as being suitable for these

Magnus Willander; Milan Friesel; Qamar-ul Wahab; Boris Straumal

2006-01-01

145

High temperature stability of langasite surface acoustic wave devices  

Microsoft Academic Search

High temperature acoustic wave (AW) devices capable of operating above 600degC and in hostile environments have opened potential applications for monitoring industrial processes, power plants, and aerospace systems. The authors have reported on the development of thin film electrodes and protective ceramic layers to allow surface acoustic wave (SAW) device operation up to 800degC on langasite (LGS) crystals. This success

M. Pereira da Cunha; R. J. Lad; T. Moonlight; G. Bernhardt; D. J. Frankel

2008-01-01

146

Verilog-A Device Models for Cryogenic Temperature Operation of Bulk Silicon CMOS Devices  

NASA Technical Reports Server (NTRS)

Verilog-A based cryogenic bulk CMOS (complementary metal oxide semiconductor) compact models are built for state-of-the-art silicon CMOS processes. These models accurately predict device operation at cryogenic temperatures down to 4 K. The models are compatible with commercial circuit simulators. The models extend the standard BSIM4 [Berkeley Short-channel IGFET (insulated-gate field-effect transistor ) Model] type compact models by re-parameterizing existing equations, as well as adding new equations that capture the physics of device operation at cryogenic temperatures. These models will allow circuit designers to create optimized, reliable, and robust circuits operating at cryogenic temperatures.

Akturk, Akin; Potbhare, Siddharth; Goldsman, Neil; Holloway, Michael

2012-01-01

147

An unheated permeation device for calibrating atmospheric VOC measurements  

NASA Astrophysics Data System (ADS)

The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs) is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as onboard aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, i.e. the instantaneous permeation rate can be ascribed via a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i) a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii) a water bath as heat buffer, and (iii) a vacuum-panel based insulation, in which features (ii) and (iii) minimize temperature drifts. The uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1 %. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 ?m) dominates.

Brito, J.; Zahn, A.

2011-05-01

148

High-Temperature RF Probe Station For Device Characterization Through 500 deg C and 50 GHz  

NASA Technical Reports Server (NTRS)

A high-temperature measurement system capable of performing on-wafer microwave testing of semiconductor devices has been developed. This high temperature probe station can characterize active and passive devices and circuits at temperatures ranging from room temperature to above 500 C. The heating system uses a ceramic heater mounted on an insulating block of NASA shuttle tile material. The temperature is adjusted by a graphical computer interface and is controlled by the software-based feedback loop. The system is used with a Hewlett-Packard 8510C Network Analyzer to measure scattering parameters over a frequency range of 1 to 50 GHz. The microwave probes, cables, and inspection microscope are all shielded to protect from heat damage. The high temperature probe station has been successfully used to characterize gold transmission lines on silicon carbide at temperatures up to 540 C.

Schwartz, Zachary D.; Downey, Alan N.; Alterovitz, Samuel A.; Ponchak, George E.; Williams, W. D. (Technical Monitor)

2003-01-01

149

Cooling device featuring thermoelectric and diamond materials for temperature control of heat-dissipating devices  

NASA Technical Reports Server (NTRS)

A cooling device for lowering the temperature of a heat-dissipating device. The cooling device includes a heat-conducting substrate (composed, e.g., of diamond or another high thermal conductivity material) disposed in thermal contact with the heat-dissipating device. During operation, heat flows from the heat-dissipating device into the heat-conducting substrate, where it is spread out over a relatively large area. A thermoelectric cooling material (e.g., a Bi.sub.2 Te.sub.3 -based film or other thermoelectric material) is placed in thermal contact with the heat-conducting substrate. Application of electrical power to the thermoelectric material drives the thermoelectric material to pump heat into a second heat-conducting substrate which, in turn, is attached to a heat sink.

Vandersande, Ian W. (Inventor); Ewell, Richard (Inventor); Fleurial, Jean-Pierre (Inventor); Lyon, Hylan B. (Inventor)

1998-01-01

150

Method for measuring surface temperature  

SciTech Connect

The present invention relates to a method for measuring a surface temperature using is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

Baker, Gary A. (Los Alamos, NM); Baker, Sheila N. (Los Alamos, NM); McCleskey, T. Mark (Los Alamos, NM)

2009-07-28

151

Low-Temperature Processes for MEMS Device Fabrication  

NASA Astrophysics Data System (ADS)

The high temperatures typical in semiconductor and conventional MEMS fabrication limit the material choices in MEMS structures. This paper reviews some of the low-temperature processes and techniques available for MEMS fabrication and describes some characteristics of these techniques and practical process examples. The techniques described are plasma-enhanced chemical vapour deposition, atomic layer deposition, reactive sputtering, vapour phase hydrofluoric acid etching of low-temperature oxides, and low-temperature wafer bonding. As a practical example of the use of these techniques, the basic characteristics of a MEMS switch and other devices fabricated at VTT are presented.

Kiihamki, Jyrki; Kattelus, Hannu; Blomberg, Martti; Puurunen, Riikka; Laamanen, Mari; Pekko, Panu; Saarilahti, Jaakko; Ritala, Heini; Rissanen, Anna

152

Diamond micro-Raman thermometers for accurate gate temperature measurements  

NASA Astrophysics Data System (ADS)

Determining the peak channel temperature in AlGaN/GaN high electron mobility transistors and other devices with high accuracy is an important and challenging issue. A surface-sensitive thermometric technique is demonstrated, utilizing Raman thermography and diamond microparticles to measure the gate temperature. This technique enhances peak channel temperature estimation, especially when it is applied in combination with standard micro-Raman thermography. Its application to other metal-covered areas of devices, such as field plates is demonstrated. Furthermore, this technique can be readily applied to other material/device systems.

Simon, Roland B.; Pomeroy, James W.; Kuball, Martin

2014-05-01

153

Junction Temperature Measurement of IGBTs Using Short Circuit Current  

SciTech Connect

In this paper, a method is proposed to measure the junction temperatures of IGBT discrete devices and modules using short circuit current. Experimental results show that the short circuit current has good sensitivity, linearity and selectivity, which is suitable to be used as temperature sensitive electrical parameters (TSEP). Test circuit and hardware design are proposed for junction temperature measurement in single phase and three phase convertes. By connecting a temperature measurement unit to the converter and giving a short circuit pulse, the IGBT junction temperature can be measured.

Wang, Fei [ORNL; Xu, Zhuxian [ORNL; Ning, Puqi [ORNL

2012-01-01

154

High Temperature Thermoelectric Device Concept Using Large Area PN Junctions  

NASA Astrophysics Data System (ADS)

A new high temperature thermoelectric device concept using large area nanostructured silicon p-type and n-type ( PN) junctions is presented. In contrast to conventional thermoelectric generators, where the n-type and p-type semiconductors are connected electrically in series and thermally in parallel, we experimentally demonstrate a device concept in which a large area PN junction made from highly doped densified silicon nanoparticles is subject to a temperature gradient parallel to the PN interface. In the proposed device concept, the electrical contacts are made at the cold side eliminating the hot side substrate and difficulties that go along with high temperature electrical contacts. This concept allows temperature gradients greater than 300 K to be experimentally applied with hot side temperatures larger than 800 K. Electronic properties of the PN junctions and power output characterizations are presented. A fundamental working principle is discussed using a particle network model with temperature and electric fields as variables, and which considers electrical conductivity and thermal conductivity according to Fourier's law, as well as Peltier and Seebeck effects.

Chavez, R.; Angst, S.; Hall, J.; Stoetzel, J.; Kessler, V.; Bitzer, L.; Maculewicz, F.; Benson, N.; Wiggers, H.; Wolf, D.; Schierning, G.; Schmechel, R.

2014-06-01

155

Energy measurement device wiring detection and examination training system design  

Microsoft Academic Search

To heighten the electrical measurement device wrong wiring detection speed and improve inspectors' working efficiency, analyzing the request of electrical measurement device wiring testing and examination training system, there put forward a whole design scheme and data collection device framework, PC Analysis system framework, and also gives a main algorithm of wrong wiring. The system has run in a ShanXi

Xingzhong Zhang; Gaoyun Liu

2009-01-01

156

High Temperature Device Characterization for Hybrid Electric Vehicle Traction Inverters  

Microsoft Academic Search

High temperature inverter involves thermal management, packaging, semiconductor device, switching circuit, and control circuitry. This paper is to focus on the drivetrain inverter design consideration for electric and hybrid electric vehicles. Basic structure and switching characteristics of different insulated-gate-bipolar-transistors (IGBTs) will be discussed. The use of silicon carbide Schottky diode in parallel with silicon IGBT will also be evaluated and

Jih-Sheng Lai; Wensong Yu; Hao Qian; Pengwei Sun; Parish Ralston; Kathleen Meehan

2009-01-01

157

Radiation effects in high temperature superconducting films and devices for the NRL high temperature superconductivity space experiment  

Microsoft Academic Search

The effects of proton irradiation on the performance of films and microwave devices made from the high temperature superconductors YBa2Cu3O7-? and Tl2Ca 2BaCu2O8 have been measured and can be explained in terms of radiation-induced changes in material parameters such as surface impedance, critical current and transition temperature. Changes in material parameters can in turn be linked to atomic displacement effects

B. D. Weaver; E. M. Jackson; G. P. Summers; D. B. Chrisey; J. S. Horwitz; J. M. Pond; H. S. Newman; E. A. Burke

1991-01-01

158

Production Engineering Measure Solid Encapsulated Semiconductor Devices.  

National Technical Information Service (NTIS)

The objective of the contract is to develop and optimize production capability for the manufacture of small signal solid encapsulated transistors capable of performing to military specifications. Both NPS (device type D32D) and PNP (Device type D34E) tran...

B. L. Bair

1970-01-01

159

Force Measurement Device for ARIANE 5 Payloads  

NASA Astrophysics Data System (ADS)

ESTEC uses since 1991 a Force Measurement Device (FMD) for the measurement of dynamic mechanical forces and moments. This tool allows the determination of forces and moments applied to the test hardware at its interface to the test facilities during dynamic testing. Three forces and three moments are calculated from the measurements of eight tri-axial force links and used to either characterize the dynamic mechanical behaviour of the test item and/or to control forces and moments during vibration testing (force limited vibration control). The current FMD is limited to test items with an interface diameter of up to about 1.2 m (adapter already available) and a mass compatible with ARIANE 4 payloads. The limitations of the current system come from the maximum of eight tri-axial force links and from the analogue technique of the Signal Processing Unit (SPU) that allows only a limited number of geometric configurations for the mechanical interface. Following the success of the FMD during former test campaigns, e.g. ROSETTA STM + FM, the need for a FMD, compatible with ARIANE 5 payloads has been established. Therefore ESA decided to develop a new FMD system. The system will include a digital real time SPU with 72 force input channels, corresponding to 24 tri-axes force sensors or 72 mono axial force sensors. The SPU design will allow extending the number of force input channels to 144. The set-up of the FMD will be done via a standard PC interface. The user will enter for each force sensor the location and the measurement direction in the reference coordinate system. Based on the geometrical information and the maximum forces and moments expected the PC will calculate the optimum range settings for the charge-amplifiers and the corresponding matrix with weighting factors which will allow to perform a fast calculation of the six output forces and moments from the 72 (or 144) input forces. The six output channels with forces and moments can then be connected either to the vibration control system or data acquisition system. The paper will present the status of the new FMD development, selection criteria for sensor and signal conditioners, trade offs performed for the various design options of the SPU and considerations about the mechanical interface design.

Brunner, O.; Braeken, R.

2004-08-01

160

Infrared Emissivity Measurements of Building and Civil Engineering Materials: A New Device for Measuring Emissivity  

NASA Astrophysics Data System (ADS)

The knowledge of the infrared emissivity of materials used in buildings and civil engineering structures is useful for two specific approaches. First, quantitative diagnosis of buildings or civil engineering infrastructures by infrared thermography requires emissivity values in the spectral bandwidth of the camera used for measurements, in order to obtain accurate surface temperatures; for instance, emissivity in the band III domain is required when using cameras with uncooled detectors (such as micro-bolometer arrays). Second, setting up accurate thermal balances by numerical modeling requires the total emissivity value for a large wavelength domain; this is, for instance, the case for computing the road surface temperature to predict ice occurrence. Furthermore, periodical surveys of emissivity variations due to aging or soiling of surfaces could be useful in many situations such as thermal mapping of roads or building insulation diagnosis. The use of portable emissivity measurement devices is required for that purpose. A device using an indirect measurement method was previously developed in our lab; the method uses measurement of the reflectivity from a modulated IR source and requires calibration with a highly reflective surface. However, that device uses a low-frequency, thermal modulation well adapted to laboratory measurements but unfit for fast and in situ measurements. Therefore, a new, portable system which retains the principle of an indirect measurement but uses a faster-frequency, mechanical modulation more appropriate to outdoor measurements was developed. Both devices allow measurements in the broad (1 \\upmu m to 40 \\upmu m) and narrow (8 \\upmu m to 14 \\upmu m) bands. Experiments were performed on a large number of materials commonly used in buildings and civil engineering structures. The final objective of this work is to build a database of emissivity of these materials. A comparison of laboratory and on-site measurements of emissivity values obtained in both spectral bands will be presented along with an estimation and an analysis of measurement uncertainties.

Monchau, Jean-Pierre; Marchetti, Mario; Ibos, Laurent; Dumoulin, Jean; Feuillet, Vincent; Candau, Yves

2013-06-01

161

Optimal color temperature adjustment for mobile devices under varying illuminants  

NASA Astrophysics Data System (ADS)

With the wide use of mobile devices, display color reproduction has become extremely important. The purpose of this study is to investigate the optimal color temperature for mobile displays under varying illuminants. The effect of the color temperature and the illuminance of ambient lighting on user preferences were observed. For a visual examination, a total of 19 nuanced whites were examined under 20 illuminants. A total of 19 display stimuli with different color temperatures (2,500 K ~ 19,600 K) were presented on an iPad3 (New iPad). The ambient illuminants ranged in color temperature from 2,500 K to 19,800 K and from 0 lx to 3,000 lx in illuminance. Supporting previous studies of color reproduction, there was found to be a positive correlation between the color temperature of illuminants and that of optimal whites. However, the relationship was not linear. Based on assessments by 56 subjects, a regression equation was derived to predict the optimal color temperature adjustment under varying illuminants, as follows: [Display Tcp = 5138.93 log(Illuminant Tcp) - 11956.59, p<.001, R2=0.94]. Moreover, the influence of an illuminant was positively correlated with the illuminance level, confirming the findings of previous studies. It is expected that the findings of this study can be used as the theoretical basis when designing a color strategy for mobile display devices.

Choi, Kyungah; Suk, Hyeon-Jeong

2014-01-01

162

Device for long term measurement of heart rate  

Microsoft Academic Search

In this contribution, a device for long term measurement of heart rate is described. The device is created based on development kit STM32-Primer2. Heart rate frequency is calculated from selected electrocardiograph lead from the external module. The device allows simultaneous recoding of acceleration which makes is appropriate for physical activity detection of the test subject. The recorded data is saved

Jakub Parak; Jan Dvorak; Jan Havlik

2011-01-01

163

A Microthermal Device for Measuring the Spatial Power Spectrum of Atmospheric Turbulence  

Microsoft Academic Search

The Measurement Astrophysics group at UNM designed and built a novel microthermal device for the purpose of characterizing atmospheric turbulence at astronomical observatories. This instrument is based on the Wheatstone bridge and uses fine wire tungsten filaments as resistance temperature detectors. The device is designed to work in two data taking modes: with a horizontal array of microthermal sensors, or

Jonathan Turner; J. McGraw; P. Zimmer; T. Williams; C. Claver; V. Krabbendam; O. Wiecha; J. Andrew; M. Warner

2009-01-01

164

Integrated Microfibre Device for Refractive Index and Temperature Sensing  

PubMed Central

A microfibre device integrating a microfibre knot resonator in a Sagnac loop reflector is proposed for refractive index and temperature sensing. The reflective configuration of this optical structure offers the advantages of simple fabrication and ease of sensing. To achieve a balance between responsiveness and robustness, the entire microfibre structure is embedded in low index Teflon, except for the 0.52 mm diameter microfibre knot resonator sensing region. The proposed sensor has exhibited a linear spectral response with temperature and refractive index. A small change in free spectral range is observed when the microfibre device experiences a large refractive index change in the surrounding medium. The change is found to be in agreement with calculated results based on dispersion relationships.

Lim, Kok-Sing; Aryanfar, Iman; Chong, Wu-Yi; Cheong, Yew-Ken; Harun, Sulaiman W.; Ahmad, Harith

2012-01-01

165

Ergonomic analysis of slip-resistance measurement devices  

Microsoft Academic Search

Several measurement devices and techniques have been developed during the past 50 years in an attempt to quantify the static and\\/or dynamic coefficient of friction (COF) of shoe and floor surface interfaces. Much of this work has been laboratory research with bulky equipment, but recently portable measurement devices have evolved to the extent that field measurements can be taken. Six

ROBERT O. ANDRES; DON B. CHAFFIN

1985-01-01

166

A low temperature integrated aluminum metallization technology for ULSI devices  

Microsoft Academic Search

An integrated aluminum metallization process (Cool Al technology) was successfully applied to fabricate device wafers for the 0.25-?m technology. This new technology integrates CVD and PVD aluminum thin film deposition processes into a high vacuum cluster tool, the applied materials Endura, and is capable of reliable contact and via fills of high aspect ratio (>8:1) structures at low temperatures, typically

Ted Guo; Liang Y Chen; Dirk Brown; Paul Besser; Steve Voss; Rod Mosely

1998-01-01

167

Compensated vibrating optical fiber pressure measuring device  

DOEpatents

A microbending optical fiber is attached under tension to a diaphragm to se a differential pressure applied across the diaphragm which it causes it to deflect. The fiber is attached to the diaphragm so that one portion of the fiber, attached to a central portion of the diaphragm, undergoes a change in tension; proportional to the differential pressure applied to the diaphragm while a second portion attached at the periphery of the diaphragm remains at a reference tension. Both portions of the fiber are caused to vibrate at their natural frequencies. Light transmitted through the fiber is attenuated by both portions of the tensioned sections of the fiber by an amount which increases with the curvature of fiber bending so that the light signal is modulated by both portions of the fiber at separate frequencies. The modulated light signal is transduced into a electrical signal. The separate modulation signals are detected to generate separate signals having frequencies corresponding to the reference and measuring vibrating sections of the continuous fiber, respectively. A signal proportional to the difference between these signals is generated which is indicative of the measured pressure differential across the diaphragm. The reference portion of the fiber is used to compensate the pressure signal for zero and span changes resulting from ambient temperature and humidity effects upon the fiber and the transducer fixture.

Fasching, George E. (Morgantown, WV); Goff, David R. (Christiansburg, VA)

1987-01-01

168

Assessment of SOI Devices and Circuits at Extreme Temperatures  

NASA Technical Reports Server (NTRS)

Electronics designed for use in future NASA space exploration missions are expected to encounter extreme temperatures and wide thermal swings. Such missions include planetary surface exploration, bases, rovers, landers, orbiters, and satellites. Electronics designed for such applications must, therefore, be able to withstand exposure to extreme temperatures and to perform properly for the duration of mission. The Low Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electrical devices, circuits, and systems suitable for applications in deep space exploration missions and aerospace environment. Silicon-On-Insulator (SOI) technology has been under active consideration in the electronics industry for many years due to the advantages that it can provide in integrated circuit (IC) chips and computer processors. Faster switching, less power, radiationtolerance, reduced leakage, and high temp-erature capability are some of the benefits that are offered by using SOI-based devices. A few SOI circuits are available commercially. However, there is a noticeable interest in SOI technology for different applications. Very little data, however, exist on the performance of such circuits under cryogenic temperatures. In this work, the performance of SOI integrated circuits, evaluated under low temperature and thermal cycling, are reported. In particular, three examples of SOI circuits that have been tested for operation at low at temperatures are given. These circuits are SOI operational amplifiers, timers and power MOSFET drivers. The investigations were carried out to establish a baseline on the functionality and to determine suitability of these circuits for use in space exploration missions at cryogenic temperatures. The findings are useful to mission planners and circuit designers so that proper selection of electronic parts can be made, and risk assessment can be established for such circuits for use in space missions.

Elbuluk, Malik; Hammoud, Ahmad; Patterson, Richard L.

2007-01-01

169

Infrared Temperature Measurements in Combustion Systems.  

National Technical Information Service (NTIS)

A technique for gas temperature measurement which uses the infrared radiation from and absorption of a hog molecular species is described. The system was developed for measuring fluctuating temperature in combustion systems and transient temperatures in s...

R. Lewin

1982-01-01

170

Modelling temperature dependence on AlGaN/GaN power HEMT device characteristics  

NASA Astrophysics Data System (ADS)

This paper reports extensive modelling and analysis of the temperature dependence on the device characteristics of the AlGaN/GaN high electron mobility transistors (HEMTs). A physics-based model is proposed in this study in order to correctly predict the gate flat-band Schottky barrier height, energy band Fermi-level (EC-EF) at the AlGaN/GaN interface, two-dimensional electron gas sheet density, gate threshold and (ID-VG) at sub-threshold voltages, and drain current-voltage (ID-VD) characteristics under various high-temperature conditions. The analytical results are then verified by comparing with the laboratory measurement as well as the numerical results obtained from the Sentaurus TCAD simulation. The proposed model is found to be useful for power electronic device designers on the prediction of the AlGaN/GaN HEMT device performance under high-temperature operation.

Wang, Yun-Hsiang; Liang, Yung C.; Samudra, Ganesh S.; Chang, Ting-Fu; Huang, Chih-Fang; Yuan, Li; Lo, Guo-Qiang

2013-12-01

171

Surface acoustic wave devices for wireless strain measurement  

NASA Astrophysics Data System (ADS)

Strain monitoring is a nondestructive inspection method that can reveal the redistribution of internal forces, or the presence of anomalous loadings, in structures. Surface acoustic wave (SAW) devices are small, robust, inexpensive solid-state components in which a wave propagates along the surface of a piezoelectric material, and such devices are used in large numbers commercially as delay devices and as filters. Changes in strain or temperature cause shifts in the acoustic wave speed, by which such SAW devices can also serve as sensors. We present analytical, FEM simulation, and experimental studies on SAW devices fabricated in our laboratory on lithium niobate wafers, with an inter-electrode spacing of 8 micrometers. We discuss the change in wave speed with temperature and with strain, we outline the influence of rotated cuts for the piezoelectric substrate, and we show results of laboratory sensing experiments. Moreover, an electrode on a SAW device can be terminated as an antenna and interrogated with a wireless RF probe to act as a passively-powered device, and we present laboratory results incorporating such wireless performance in our research investigation. We pattern one set of electrodes on the SAW device as a transducer connected to the antenna, and other sets of electrodes on the device acting as reflectors of the surface acoustic wave. At the RF frequencies used for SAW devices, it is realistic to use directional antennas on the probe unit to achieve reasonable stand-off distances.

Chin, T.-L.; Zheng, Peng; Oppenheim, Irving J.; Greve, David W.

2010-03-01

172

21 CFR 886.1450 - Corneal radius measuring device.  

Code of Federal Regulations, 2010 CFR

A corneal radius measuring device is an AC-powered device intended to measure corneal size by superimposing the image of the cornea on a scale at the focal length of the lens of a small, hand held, single tube penscope or eye gauge magnifier. (b) Classification. Class I (general...

2010-04-01

173

21 CFR 886.1450 - Corneal radius measuring device.  

Code of Federal Regulations, 2010 CFR

A corneal radius measuring device is an AC-powered device intended to measure corneal size by superimposing the image of the cornea on a scale at the focal length of the lens of a small, hand held, single tube penscope or eye gauge magnifier. (b) Classification. Class I (general...

2009-04-01

174

Measured minority-carrier lifetime and CIGS device performance  

Microsoft Academic Search

The relationship between lifetime measured by time-resolved photoluminescence on bare CIGS films and subsequent device performance is examined. A correlation between device voltage and lifetime is demonstrated. The effects of measured band gap and carrier density are discussed. Results are compared with fundamental calculations.

Ingrid L. Repins; Wyatt K. Metzger; Craig L. Perkins; Jian V. Li; Miguel A. Contreras

2009-01-01

175

Simple and compact device for measuring ultrashort-laser pulses  

Microsoft Academic Search

A new method of using thick nonlinear crystals to make measurements of ultrashort-laser pulses was explored theoretically and experimentally. Initial experiments using dithered thick nonlinear crystals showed good agreement with established techniques, with an increase in measurement sensitivity. A device using a thick nonlinear crystal and a special prism was designed, built, and tested. The device showed good agreement with

Patrick Donald O'Shea

2003-01-01

176

PROGRESS IN VACUUM MEASUREMENT DEVICES USING RADIOACTIVE MATERIALS  

Microsoft Academic Search

The alphatron,'' a vacuum measurement device using radioactive ; sources, is described. Improvements to the standard device with respect to the ; radiation danger and to the construction are discussed. The principle of an ; alphatron is considered in some detail. The radiation source, the ionization ; chambers, and the measurement amplifier are discussed. (J.S.R.);

Moreau

1962-01-01

177

Physically Meaningful Harmonization of Tire\\/Pavement Friction Measurement Devices  

Microsoft Academic Search

Accurate characterization and evaluation of tire\\/pavement friction is critical in assuring runway and highway safety. Historically, Pavement Friction Measurement Devices (PFMDs) employing different measuring mechanisms have been used to evaluate tire\\/pavement friction. They yield significantly disparate friction coefficients under the same contact conditions. Currently, an empirically developed data harmonization method based on a reference device (Dynamic Friction Tester (DFT)) is

Madhura Priyanga Nishshanke Rajapakshe

2011-01-01

178

Miniature wireless photoplethysmography devices: integration in garments and test measurements  

NASA Astrophysics Data System (ADS)

Wireless PPG devices were developed and embedded in everyday clothes (bandage, scarf, cycling glove and wrist strap) to monitor cardiovascular state of free-moving persons. The corresponding software for measurements also has been developed and tested in laboratory. Real-time measurements of PPG signals were taken in parallel with a professional ECG reference device, and high correlation was demonstrated.

Kviesis-Kipge, E.; Me??ika, V.; Rubenis, O.

2012-05-01

179

Improved system measures output energy of pyrotechnic devices  

NASA Technical Reports Server (NTRS)

System for measuring the output energy of pyrotechnic devices discharges the reaction products into a test chamber. It measures the radiant heat output from a pinhole aperture as well as internal pressure changes on a common time base.

Shortly, E. M.

1966-01-01

180

Laser Pyrometer For Spot Temperature Measurements  

NASA Technical Reports Server (NTRS)

Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

Elleman, D. D.; Allen, J. L.; Lee, M. C.

1988-01-01

181

Graphene, a material for high temperature devices - intrinsic carrier density, carrier drift velocity, and lattice energy  

PubMed Central

Heat has always been a killing matter for traditional semiconductor machines. The underlining physical reason is that the intrinsic carrier density of a device made from a traditional semiconductor material increases very fast with a rising temperature. Once reaching a temperature, the density surpasses the chemical doping or gating effect, any p-n junction or transistor made from the semiconductor will fail to function. Here, we measure the intrinsic Fermi level (|EF| = 2.93?kBT) or intrinsic carrier density (nin = 3.87 106?cm?2K?2T2), carrier drift velocity, and G mode phonon energy of graphene devices and their temperature dependencies up to 2400?K. Our results show intrinsic carrier density of graphene is an order of magnitude less sensitive to temperature than those of Si or Ge, and reveal the great potentials of graphene as a material for high temperature devices. We also observe a linear decline of saturation drift velocity with increasing temperature, and identify the temperature coefficients of the intrinsic G mode phonon energy. Above knowledge is vital in understanding the physical phenomena of graphene under high power or high temperature.

Yin, Yan; Cheng, Zengguang; Wang, Li; Jin, Kuijuan; Wang, Wenzhong

2014-01-01

182

Graphene, a material for high temperature devices - intrinsic carrier density, carrier drift velocity, and lattice energy.  

PubMed

Heat has always been a killing matter for traditional semiconductor machines. The underlining physical reason is that the intrinsic carrier density of a device made from a traditional semiconductor material increases very fast with a rising temperature. Once reaching a temperature, the density surpasses the chemical doping or gating effect, any p-n junction or transistor made from the semiconductor will fail to function. Here, we measure the intrinsic Fermi level (|EF| = 2.93?kBT) or intrinsic carrier density (nin = 3.87 10(6)?cm(-2)K(-2)T(2)), carrier drift velocity, and G mode phonon energy of graphene devices and their temperature dependencies up to 2400?K. Our results show intrinsic carrier density of graphene is an order of magnitude less sensitive to temperature than those of Si or Ge, and reveal the great potentials of graphene as a material for high temperature devices. We also observe a linear decline of saturation drift velocity with increasing temperature, and identify the temperature coefficients of the intrinsic G mode phonon energy. Above knowledge is vital in understanding the physical phenomena of graphene under high power or high temperature. PMID:25044003

Yin, Yan; Cheng, Zengguang; Wang, Li; Jin, Kuijuan; Wang, Wenzhong

2014-01-01

183

21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Ophthalmic contact lens radius measuring device. 886...Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device is...

2009-04-01

184

21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Ophthalmic contact lens radius measuring device. 886...Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device is...

2013-04-01

185

MEMS Device Being Developed for Active Cooling and Temperature Control  

NASA Technical Reports Server (NTRS)

High-capacity cooling options remain limited for many small-scale applications such as microelectronic components, miniature sensors, and microsystems. A microelectromechanical system (MEMS) is currently under development at the NASA Glenn Research Center to meet this need. It uses a thermodynamic cycle to provide cooling or heating directly to a thermally loaded surface. The device can be used strictly in the cooling mode, or it can be switched between cooling and heating modes in milliseconds for precise temperature control. Fabrication and assembly are accomplished by wet etching and wafer bonding techniques routinely used in the semiconductor processing industry. Benefits of the MEMS cooler include scalability to fractions of a millimeter, modularity for increased capacity and staging to low temperatures, simple interfaces and limited failure modes, and minimal induced vibration.

Moran, Matthew E.

2001-01-01

186

Thermal imaging and measurement techniques for electronic materials and devices  

Microsoft Academic Search

The temperature stress occurring during electrical operation plays an important part in optimizing the performance and reliability of electronic devices. Thermal stress results from short transient processes (that can lead to critical junction temperatures within the chip) as well as from long-term cyclic stresses in a real system environment. The thermal characterization of materials, electronic components and modules by experiment

J. Klzer; E. Oesterschulze; G. Deboy

1996-01-01

187

Temperature Measurements in Normal and Tumor Tissue of Dogs Undergoing Whole Body Hyperthermia1  

Microsoft Academic Search

Temperature was measured in the left ventricle, aorta, liver, brain, lung, bone marrow, kidney, and spontaneous solid tumors in dogs undergoing whole body hyperthermia in a radiant heat device. Rectal temperature was found to be a satisfactory indicator of systemic arterial temperature during plateau temperature conditions but rectal temperature underestimated arterial temperature during heating and overestimated it during cooling. Lung

Donald E. Thrall; Rodney L. Page; Mark W. Dewhirst; Robert E. Meyer; P. Jack Hoopes; Joe N. Kornegay

188

Chip Implementation with a Combined Wireless Temperature Sensor and Reference Devices Based on the DZTC Principle  

PubMed Central

This paper presents a novel CMOS wireless temperature sensor design in order to improve the sensitivity and linearity of our previous work on such devices. Based on the principle of CMOS double zero temperature coefficient (DZTC) points, a combined device is first created at the chip level with two voltage references, one current reference, and one temperature sensor. It was successfully fabricated using the 0.35 ?m CMOS process. According to the chip results in a wide temperature range from ?20 C to 120 C, two voltage references can provide temperature-stable outputs of 823 mV and 1,265 mV with maximum deviations of 0.2 mV and 8.9 mV, respectively. The result for the current reference gives a measurement of 23.5 ?A, with a maximum deviation of 1.2 ?A. The measurements also show that the wireless temperature sensor has good sensitivity of 9.55 mV/C and high linearity of 97%. The proposed temperature sensor has 4.15-times better sensitivity than the previous design. Moreover, to facilitate temperature data collection, standard wireless data transmission is chosen; therefore, an 8-bit successive-approximation-register (SAR) analog-to-digital converter (ADC) and a 433 MHz wireless transmitter are also integrated in this chip. Sensing data from different places can be collected remotely avoiding the need for complex wire lines.

Chang, Ming-Hui; Huang, Yu-Jie; Huang, Han-Pang; Lu, Shey-Shi

2011-01-01

189

Devices for moisture measurement in natural gas  

SciTech Connect

The Dew Point Tester incorporates a pressure-tight chamber to contain the gas or vapor test sample and valves for controlling gas flow. At one end of the chamber, a clear plastic window is installed to allow observation of the chamber's interior and mirror. The mirror is highly polished stainless steel and is attached at its center to a copper thermometer well. A chiller attached to the thermometer well controls expansion of refrigerant and the temperature of the mirror. The mirror's temperature is indicated by a thermometer whose bulb is located close to the mirror's back surface.

Kahmann, A.R.

1984-04-01

190

Hand-Held Device to Measure Finger (Thumb) Strength.  

National Technical Information Service (NTIS)

A device that measures, the force exerted by the thumb or fingers, is described. This device is hand-held, easily calibrated, and is adjustable to various hand sizes and digit positions. Thumb strength data from 31 male subjects is reported. (Author)

E. M. Gienapp K. H. E. Kroemer

1970-01-01

191

Novel Multi-Aperture Device for Surface Roughness Measurement.  

National Technical Information Service (NTIS)

The objective of this research program is to develop a novel multi- aperture device for the surface roughness measurement. The successful fabrication of this novel device can provide the U.S. Army a handy, in situ, cost-effective. real-time tool for the p...

S. Yin

2000-01-01

192

A cross-polarized bistatic calibration device for RCS measurements  

Microsoft Academic Search

A little known unidirectionally conducting canonical object is introduced, which satisfies the requirements for use as a cross-polarized bistatic calibration device, including a signature with the desirable property of being able to be characterized analytically. Bistatic measurements are essential to understanding the stealth characteristics of military targets, and since no similar cross-polarization calibration target is available, the proposed device shows

Cesar Monzon

2003-01-01

193

Novel temperature compensation technique for force-sensing piezoresistive devices  

NASA Astrophysics Data System (ADS)

A novel stress-insensitive piezoresistor in the shape of an annulus has been developed to be used in conjunction with a piezoresistive bridge for temperature-compensated force measurements. Under uniform stress conditions, the annular resistor shows near-zero stress sensitivity and a linear response to temperature excitation within test conditions of 24-34 C. Annular resistors were placed in close proximity to stress-sensitive elements in order to detect local temperature fluctuations. Experiments evaluating the performance of the temperature compensator while testing force sensitivity showed a thermal rejection ratio of 37.2 dB and near elimination of low-frequency noise (drift) below 0.07 Hz. Potential applications of this annular resistor include use in multi-axis force sensors for force feedback microassembly, improvements in the simplicity and robustness of high precision microgram sensitive balances, higher accuracy for silicon diaphragm-based pressure sensors and simple temperature compensation for AFM cantilevers.

Scott, Joshua; Enikov, Eniko T.

2011-11-01

194

Temperature Measurement in Nuclear Environment.  

National Technical Information Service (NTIS)

Some criterions, that the used sensors have to follow, are given together with the conditions they may encountered. They may be used in irradiation or safety test devices, in experiments concerning mock-up or plant element, or even in nuclear plants thems...

P. Degas

1986-01-01

195

Concept for improved vacuum pressure measuring device  

NASA Technical Reports Server (NTRS)

To measure vacuum pressures in the range of 5 times 10 to the minus 7 to 5 times 10 to the minus 16, a semiconductor resistor composed of sintered zinc oxide is used. Through the effect of surface absorbed gases on the resistance of the semiconductor material, very low pressures are measured.

Medved, D. B.

1969-01-01

196

Attachment alignment measurement system, method and device  

US Patent & Trademark Office Database

The present invention provides an Attachment alignment measurement system, method and tool, for identifying the level of Attachment Variance in a relationship between a caregiver and a subject (e.g. new member) in the social structure. Attachment Variance is the degree of alignment (or misalignment) between a subject's (e.g. new member) actual Attachment to the social structure compared with the Attachment of the subject as perceived by the caregiver. The Attachment alignment measurement method for measuring attachment variance in social structure, including the steps of measuring a Subject's actual Attachment to a social structure (Actual Attachment), measuring a primary carer's perception of the Subject's Attachment to a social structure (Perceived Attachment), and comparing Actual Attachment and Perceived Attachment such that Attachment Variance is assessable, wherein Attachment Variance provides an indication of alignment between a Subject's Actual Attachment the Perceived Attachment and the programming instructions for performing the steps.

2014-04-01

197

Nanocalorimetry: Using Si-micromachined Devices for Thermodynamic Measurements of Thin Films and Tiny Crystals  

NASA Astrophysics Data System (ADS)

We have used Si micromachining to fabricate membrane-based calorimeters for measuring thermodynamic properties of microgram-quantity samples over a temperature range from 1.7 to 550K in magnetic fields to 8T. Prototype scaled down devices have been made which allow precise measurements of nanogram quantities. Different types of thermometers are used for different purposes and in different temperature ranges. Current development efforts are extending the temperature range to 0.3 - 800K, and we are collaborating with the national high magnetic field lab to extend the field range to 65T in pulsed magnets. These devices are particularly useful for specific heat measurements of thin film samples (100-400 nm thick) deposited directly onto the membrane through a Si micromachined evaporation mask. They have also been used for small bulk samples attached by conducting paint or In, and for powder samples dissolved in a solvent and dropped onto devices. The measurement technique used (relaxation method) is particularly suited to high fields because thermal conductance is measured in zero field and is field independent, while the relaxation time constant does not depend on thermometer calibration. The devices have been used with little modification for thermal conductivity and thermopower measurements, and are well suited to measurements of calorimetric signals such as those occurring at phase transitions or under irreversible thermal behavior. I will discuss device fabrication and thermal analysis which allow us to precisely identify heat flow in the devices and consequent limits on the absolute accuracy, as well as possible future directions for device development. I will also briefly discuss examples of measurements on several materials of current interest: 1) amorphous Si and its alloys, 2) high precision critical temperature studies of La1-xSrxMnO3 and La1-xCaxMnO3, 3) antiferromagnetic CoO nanoparticles and thin layers, 4) Fe/Cr giant magnetoresistance multilayers.

Hellman, Frances

2006-03-01

198

A low-temperature sample orienting device for single crystal spectroscopy at the SNS  

SciTech Connect

A low temperature sample orientation device providing three axes of rotation has been successfully built and is in testing for use on several spectrometers at the spallation neutron source (SNS). Sample rotation about the vertical ({omega}) axis of nearly 360{sup o} and out of plane tilts ({phi} and {nu}) of from -3.4{sup o} to 4.4{sup o} and from -2.8{sup o} to 3.5{sup o}, respectively, are possible. An off-the-shelf closed cycle refrigerator (CCR) is mounted on a room temperature sealed rotary flange providing {omega} rotations of the sample. Out-of-plane tilts are made possible by piezoelectric actuated angular positioning devices mounted on the low temperature head of the CCR. Novel encoding devices based on magnetoresistive sensors have been developed to measure the tilt stage angles. This combination facilitates single crystal investigations from room temperature to 3.1 K. Commissioning experiments of the rotating CCR for both powder and single crystal samples have been performed on the ARCS spectrometer at the SNS. For the powder sample this device was used to continuously rotate the sample and thus average out any partial orientation of the powder. The powder rings observed in S(Q) are presented. For the single crystal sample, the rotation was used to probe different regions of momentum transfer (Q-space). Laue patterns obtained from a single crystal sample at two rotation angles are presented.

Bruce, Douglas R [ORNL; Gaulin, Bruce D. [McMaster University; Granroth, Garrett E [ORNL; Roberts II, Charles K [ORNL; Sherline, Todd E [ORNL; Solomon, Landon M [ORNL

2010-01-01

199

Impact of Time Measurement Devices on Maintenance Data Systems.  

National Technical Information Service (NTIS)

The purpose of the report is to devise a procedure to evaluate the effectiveness of maintenance data acquisition systems, and to subsequently analyze the effect of time measurement devices on these data systems.

J. A. Hafen

1967-01-01

200

Extremely simple device for measuring ultrashort pulses in the visible  

Microsoft Academic Search

We demonstrate an extremely simple frequency-resolved-optical-gating device (GRENOUILLE) ideal for measuring visible ultrashort pulses. By angle-tuning a thick crystal, its range includes almost the entire visible spectrum.

Dongjoo Lee; Rick Trebino

2009-01-01

201

Methods of Measurement for Semiconductor Materials, Process Control, and Devices.  

National Technical Information Service (NTIS)

The report, describes NBS activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices. Significant accomplishments include development of a procedure to correct for the substantial differe...

W. M. Bullis

1972-01-01

202

Methods of Measurement for Semiconductor Materials, Process Control, and Devices.  

National Technical Information Service (NTIS)

The report describes NBS activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices. Significant accomplishments during this reporting period include design of a plan to provide standard ...

W. M. Bullis

1973-01-01

203

29. HAWSER DEVICE, DEVELOPED AT WES FOR MEASURING LONGITUDINAL AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

29. HAWSER DEVICE, DEVELOPED AT WES FOR MEASURING LONGITUDINAL AND TRANSVERSE STRESS OF BARGES IN CANAL LOCKS. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

204

Optical distance measurement device and method thereof  

DOEpatents

A system and method of efficiently obtaining distance measurements of a target. A modulated optical beam may be used to determine the distance to the target. A first beam splitter may be used to split the optical beam and a second beam splitter may be used to recombine a reference beam with a return ranging beam. An optical mixing detector may be used in a receiver to efficiently detect distance measurement information.

Bowers, Mark W. (Patterson, CA)

2003-05-27

205

Experimental device for measuring the momentum of disperse granular materials  

SciTech Connect

An experimental device for measuring the time averaged momentum associated with a steady stream of a disperse granular material has been developed. The mathematical basis for the device is presented including a discussion of using the momentum measurement to compute the local mass or energy fluxes. The analysis considers both nonuniform particle mass and nonuniform velocities for the various constituents of an aggregate material. The results of calibration experiments conducted with a prototype transducer are shown with theoretical predictions of these results.

Watling, H.E.; Griffiths, S.K.

1982-02-10

206

Optical Temperature Measurement Method for Glowing Microcomponents  

NASA Astrophysics Data System (ADS)

A measurement method and measurement results for the temperature of miniature microbridge emitters integrated on silicon are presented. First, the extinction coefficient of highly doped silicon was measured at high temperatures: a piece of a silicon-on-insulator wafer was heated to several temperatures in a high-temperature furnace, and the emitted spectra were measured using a spectroradiometer with focusing optics. The optical behavior of the sample was modeled with Fresnel equations. The extinction coefficient of silicon was obtained from the model, because other optical properties, the dimensions, and the temperature of the structure were known. An emissivity model was then developed and adapted for the microbridge with the known extinction coefficient values, which allows the temperature to be determined from the measured spectrum. We can now measure optically the temperatures of the microbridges of dimensions 400 25 4 ?m3 in the temperature range 600 C to 1200 C with an uncertainty of 100 C.

Shpak, M.; Krh, P.; Ojanen, M.; Ikonen, E.; Heinonen, M.

2010-09-01

207

Optical Distance Measurement Device And Method Thereof  

DOEpatents

A system and method of efficiently obtaining distance measurements of a target by scanning the target. An optical beam is provided by a light source and modulated by a frequency source. The modulated optical beam is transmitted to an acousto-optical deflector capable of changing the angle of the optical beam in a predetermined manner to produce an output for scanning the target. In operation, reflected or diffused light from the target may be received by a detector and transmitted to a controller configured to calculate the distance to the target as well as the measurement uncertainty in calculating the distance to the target.

Bowers, Mark W. (Patterson, CA)

2004-06-15

208

Acoustic Device Would Measure Density Of Gas  

NASA Technical Reports Server (NTRS)

Proposed acoustic sensor measures density of flowing gas or mixture of gases. Constructed in variety of configurations for use in monitoring industrial processes. Basic configuration, sensor comprises narrow tube closed at one end and open at other, sound transmitter located in closed end, and microphone located part way along tube. Entire sensor, or at least open end of tube, placed inside pipe or vessel containing gas, density of which measured. Transducer produces constant-velocity-amplitude sound waves at frequency lower than fundamental resonant frequency of tube.

Shakkottai, Parthasarathy; Kwack, Eug Y.; Back, Lloyd H.

1992-01-01

209

Apparatus Would Measure Temperatures Of Ball Bearings  

NASA Technical Reports Server (NTRS)

Rig for testing ball bearings under radial and axial loads and measuring surface temperatures undergoing development. Includes extensible thermocouples: by means of bellows as longitudinal positioners, thermocouples driven into contact with bearing balls to sense temperatures immediately after test run. Not necessary to disassemble rig or to section balls to obtain indirect indications of maximum temperatures reached. Thermocouple measurements indicate temperatures better than temperature-sensitive paints.

Gibson, John C.; Fredricks, Thomas H.

1995-01-01

210

Ultrasonic device for measuring periodontal attachment levels  

Microsoft Academic Search

Periodontal disease is manifested clinically by a degradation of the ligament that attaches the tooth to the bone. The most widely used diagnostic tool for assessment of periodontal diseases, measurement of periodontal attachment loss with a manual probe, may overestimate attachment loss by as much as 2 mm in untreated sites, while underestimating attachment loss by an even greater margin

J. E. Lynch; M. K. Hinders

2002-01-01

211

Apparatus for Measuring Semiconductor Device Resistance.  

National Technical Information Service (NTIS)

A test structure for accurately measuring the sheet resistance of the diffused region of a semiconductor during processing is provided. The novel feature is that one of the terminals extends in a closed path around the other terminal so that all current f...

W. J. Matzen

1978-01-01

212

Uncertainty of temperature measurement with thermal cameras  

Microsoft Academic Search

All main international metrological organizations are proposing a parameter called uncertainty as a measure of the accuracy of measurements. A mathematical model that enables the calculations of uncertainty of temperature measurement with thermal cameras is presented. The standard uncertainty or the expanded uncertainty of temperature measurement of the tested object can be calculated when the bounds within which the real

Krzysztof Chrzanowski; Robert Matyszkiel; Joachim Fischer; Jaroslaw Barela

2001-01-01

213

Low-cost optoelectronic devices to measure velocity of detonation  

NASA Astrophysics Data System (ADS)

Velocity of Detonation (VoD) is an important measured characteristic parameter of explosive materials. When new explosives are developed, their VoD must be determined. Devices used to measure VoD are always destroyed in the process, however replacing these devices represents a considerable cost in the characterisation of new explosives. This paper reports the design and performance of three low-cost implementations of a point-to-point VoD measurement system, two using optical fibre and a third using piezoelectric polymers (PolyVinyliDine Flouride, PVDF). The devices were designed for short charges used under controlled laboratory conditions and were tested using the common explosive 'Composition B'. These new devices are a fraction of the cost of currently available VoD sensors and show promise in achieving comparable accuracy. Their future development will dramatically reduce the cost of testing and aid the characterisation of new explosives.

Chan, Edwin M.; Lee, Vivian; Mickan, Samuel P.; Davies, Phil J.

2005-02-01

214

Apparatus for measuring semiconductor device resistance  

NASA Technical Reports Server (NTRS)

A test structure is described for enabling the accurate measurement of the resistance characteristics of a semiconductor material and includes one or more pairs of electrical terminals disposed on the surface of the material to enable measurements of the resistance encountered by currents passed between the terminals. A pair of terminals includes a first terminal extending in a closed path, such as a circle, around a second terminal, so that all currents flowing between the terminals flow along a region of known width and length. Two or more pairs of concentric terminals can be utilized, wherein the ratio of radii of each pair of terminals is the same as the ratio for all other pairs of terminals, to facilitate the calculation of the contact resistance between each terminal and the semiconductor surface, as well as the calculation of the resistance of the semiconductor material apart from the effect of the terminal to semiconductor contact resistances.

Matzen, W. J. (inventor)

1980-01-01

215

Nanocalorimetry: Using Si-micromachined Devices for Thermodynamic Measurements of Thin Films and Tiny Crystals  

Microsoft Academic Search

We have used Si micromachining to fabricate membrane-based calorimeters for measuring thermodynamic properties of microgram-quantity samples over a temperature range from 1.7 to 550K in magnetic fields to 8T. Prototype scaled down devices have been made which allow precise measurements of nanogram quantities. Different types of thermometers are used for different purposes and in different temperature ranges. Current development efforts

Frances Hellman

2006-01-01

216

Measurement of small temperature fluctuations at high average temperature  

NASA Technical Reports Server (NTRS)

Both absolute and differential temperature measurements were simultaneously performed as a function of time for a pixel on a high-temperature, multi-spectral, spatially and temporally varying infrared target simulator. A scanning laser beam was used to maintain a pixel at an on-the-average constant temperature of 520 K. The laser refresh rate of up to 1 kHz resulted in small-amplitude temperature fluctuations with a peak-to-peak amplitude of less than 1 K. The experimental setup to accurately measure the differential and the absolute temperature as a function of time is described.

Scholl, James W.; Scholl, Marija S.

1988-01-01

217

Measurement of thermodynamic temperature of high temperature fixed points  

SciTech Connect

The paper is devoted to VNIIOFI's measurements of thermodynamic temperature of the high temperature fixed points Co-C, Pt-C and Re-C within the scope of the international project coordinated by the Consultative Committee for Thermometry working group 5 'Radiation Thermometry'. The melting temperatures of the fixed points were measured by a radiance mode radiation thermometer calibrated against a filter radiometer with known irradiance spectral responsivity via a high temperature black body. This paper describes the facility used for the measurements, the results and estimated uncertainties.

Gavrilov, V. R.; Khlevnoy, B. B.; Otryaskin, D. A.; Grigorieva, I. A.; Samoylov, M. L.; Sapritsky, V. I. [All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), 46 Ozernaya St., Moscow 119361 (Russian Federation)] [All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), 46 Ozernaya St., Moscow 119361 (Russian Federation)

2013-09-11

218

Effects of chamber pressure variation on the grid temperature in an inertial electrostatic confinement device  

Microsoft Academic Search

Inertial electrostatic confinement fusion devices are compact sources of neutrons, protons, electrons, and x rays. Such sources have many applications. Improving the efficiency of the device also increases the applications of this device. Hence a thorough understanding of the operation of this device is needed. In this paper, we study the effect of chamber pressure on the temperature of the

S. Krupakar Murali; G. A. Emmert; J. F. Santarius; G. L. Kulcinski

2010-01-01

219

Pyrometric Gas and Surface Temperature Measurements  

NASA Technical Reports Server (NTRS)

A multiwavelength pyrometer possessing advantages over the one- and two-wavelength designs is described. Results of its application to surface temperature measurements of ceramics is presented. Also described is a probe suitable for gas temperature measurements to temperatures > 2600 K. The design of the probe includes a multiwavelength pyrometer with fiber optic input.

Fralick, Gustave; Ng, Daniel

1999-01-01

220

Emitted vibration measurement device and method  

NASA Technical Reports Server (NTRS)

This invention is directed to a method and apparatus for measuring emitted vibrational forces produced by a reaction wheel assembly due to imbalances, misalignment, bearing defects and the like. The apparatus includes a low mass carriage supported on a large mass base. The carriage is in the form of an octagonal frame having an opening which is adapted for receiving the reaction wheel assembly supported thereon by means of a mounting ring. The carriage is supported on the base by means of air bearings which support the carriage in a generally frictionless manner when supplied with compressed air from a source. A plurality of carriage brackets and a plurality of base blocks provided for physical coupling of the base and carriage. The sensing axes of the load cells are arranged generally parallel to the base and connected between the base and carriage such that all of the vibrational forces emitted by the reaction wheel assembly are effectively transmitted through the sensing axes of the load cells. In this manner, a highly reliable and accurate measurment of the vibrational forces of the reaction wheel assembly can be had. The output signals from the load cells are subjected to a dynamical analyzer which analyzes and identifies the rotor and spin bearing components which are causing the vibrational forces.

Gisler, G. L. (inventor)

1986-01-01

221

Transverse end effect for a high temperature superconductor electrodynamic levitation device  

NASA Astrophysics Data System (ADS)

In this paper, an electrodynamic levitation device with high temperature superconductor windings and nonferromagnetic secondary is proposed. Because of the proposed device's dimensions vary with its radius, current distribution on the secondary reaction plate is not symmetrical. Therefore, traditional approach to apply correction coefficient are not accurate. In this paper, we propose to use an effective three dimensional analysis model for considering the transverse edge effect caused by the primary and the secondary. Further, we show a simple method of measuring the transverse edge effect by using the patterns of currents induced in the secondary reaction plate. With this effective analysis method, the distribution of current, magnetic field, and normal force in the secondary reaction plate is analyzed. The radial length of the device is optimized.

Shuo, Li; Yu, Fan; Xi, Zhu

2014-05-01

222

Finger temperature controller for non-invasive blood glucose measurement  

NASA Astrophysics Data System (ADS)

Blood glucose level is an important parameter for doctors to diagnose and treat diabetes. The Near-Infra-Red (NIR) spectroscopy method is the most promising approach and this involves measurement on the body skin. However it is noted that the skin temperature does fluctuate with the environmental and physiological conditions and we found that temperature has important influences on the glucose measurement. In-vitro and in-vivo investigations on the temperature influence on blood glucose measurement have been carried out. The in-vitro results show that water temperature has significant influence on water absorption. Since 90% of blood components are water, skin temperature of measurement site has significant influence on blood glucose measurement. Also the skin temperature is related to the blood volume, blood volume inside capillary vessels changes with skin temperature. In this paper the relationship of skin temperature and signal from the skin and inside tissue was studied at different finger temperatures. Our OGTT (oral glucose tolerance test) trials results show the laser signals follow the skin temperature trend and the correlation of signal and skin temperature is much stronger than the correlation of signal and glucose concentration. A finger heater device is designed to heat and maintain the skin temperature of measurement site. The heater is controlled by an electronic circuit according to the skin temperature sensed by a thermocouple that is put close to the measurement site. In vivo trials were carried out and the results show that the skin temperature significantly influences the signal fluctuations caused by pulsate blood and the average signal value.

Zhang, Xiqin; Ting, Choon Meng; Yeo, Joon Hock

2010-11-01

223

Photoluminescence-Based Electron and Lattice Temperature Measurements in GaN-Based HEMTs  

NASA Astrophysics Data System (ADS)

Nitride-based semiconductors are gaining importance not only for high-power applications but also for high-temperature electronic devices. Using photoluminescence (PL) techniques, it is now possible to simultaneously determine the temperatures of the lattice and hot electrons in these devices. Therefore, it is possible to use PL mapping measurements to derive temperature profiles for electrons and the lattice in the active region of an operating device with a single set of measurements. This work presents an experimental process to construct such spatially resolved temperature maps for a planar semiconductor device under bias and applies this approach to a specific example using the conductive channels of a biased AlGaN/GaN high-electron-mobility transistor. Studying the temperature distribution inside the conductive channels will help understand how electrons flowing in the device interact with the lattice as well as the process of heat generation within the device.

Ferrer-Prez, Jorge A.; Claflin, Bruce; Jena, Debdeep; Sen, Mihir; Vetury, Ramakrishna; Dorsey, Donald

2014-02-01

224

Measurements of particle temperature under combustion.  

National Technical Information Service (NTIS)

The particle temperature is a crucial parameter with respect of the characterization of the properties and behaviours of pulverized fuels. The surface temperature measurement of coal particles is studied in an atmospheric entrained-flow reactor and a pres...

S. Clausen

1996-01-01

225

Heated Surface Temperatures Measured by Infrared Detector in a Cascade Environment.  

National Technical Information Service (NTIS)

Investigators have used infrared devices to accurately measure heated surface temperatures. Several of these applications have been for turbine heat transfer studies involving film cooling and surface roughness, typically, these measurements use an infrar...

R. J. Boyle

2002-01-01

226

Microactuator device for integrated measurement of epithelium mechanics  

PubMed Central

Mechanical forces are among important factors that drive cellular function and organization. We present a microfabricated device with on-chip actuation for mechanical testing of single cells. An integrated immersible electrostatic actuator system is demonstrated that applies calibrated forces to cells. We conduct stretching experiments by directly applying forces to epithelial cells adhered to device surfaces functionalized with collagen. We measure mechanical properties including stiffness, hysteresis and visco-elasticity of adherent cells.

Mukundan, Vikram; Nelson, W. James; Pruitt, Beth L.

2012-01-01

227

Noncontact Measurement of Humidity and Temperature Using Airborne Ultrasound  

NASA Astrophysics Data System (ADS)

We describe a noncontact method for measuring humidity and dry-bulb temperature. Conventional humidity sensors are single-point measurement devices, so that a noncontact method for measuring the relative humidity is required. Ultrasonic temperature sensors are noncontact measurement sensors. Because water vapor in the air increases sound velocity, conventional ultrasonic temperature sensors measure virtual temperature, which is higher than dry-bulb temperature. We performed experiments using an ultrasonic delay line, an atmospheric pressure sensor, and either a thermometer or a relative humidity sensor to confirm the validity of our measurement method at relative humidities of 30, 50, 75, and 100% and at temperatures of 283.15, 293.15, 308.15, and 323.15 K. The results show that the proposed method measures relative humidity with an error rate of less than 16.4% and dry-bulb temperature with an error of less than 0.7 K. Adaptations of the measurement method for use in air-conditioning control systems are discussed.

Akihiko Kon,; Koichi Mizutani,; Naoto Wakatsuki,

2010-04-01

228

Fiber-coupled photoconductive sampling for time-resolved transport measurements of cryogenic devices  

NASA Astrophysics Data System (ADS)

Photoconductive sampling can measure both the amplitude and phase components of the impulse response of cryogenic mesoscopic devices on a picosecond time scale. Mesoscopic devices that operate at temperatures < 1 K are difficult to measure because of constraints on the maximum tolerable thermal loading through optical windows that pass the optical pulses required to drive the photoconductive switches. We have developed a new technique that avoids using optical windows altogether. Two short lengths of optical fiber are pigtailed to the photoconductive switches and couple picosecond optical pulses through the walls of the cryostat. The photoconductive switches have meandered active areas that were defined by electron beam lithography. The system has been operated at liquid helium temperatures using < 1 mW of average optical power, with a time resolution of 5 picoseconds. Preliminary efforts in measuring cryogenic three terminal devices will be discussed. ^Also at MIT Lincoln Laboratory, Lexington MA.

Verghese, S.; Zamdmer, N.; Hu, Q.; Frster, A.

1996-03-01

229

Extremely simple device for measuring 20-fs pulses.  

PubMed

We demonstrate an extremely simple frequency-resolved optical-gating device (GRENOUILLE) capable of measuring pulses with spectra wider than 100 nm. Its nearly all-reflective geometry minimizes the material dispersion, allowing accurate measurement of pulses as short as 19 fs. PMID:15143662

Akturk, Selcuk; Kimmel, Mark; O'Shea, Patrick; Trebino, Rick

2004-05-01

230

A new Force Measurement Device for spacecraft testing  

NASA Astrophysics Data System (ADS)

A new Force Measurement Device (FMD) has been used during the sine-vibration testing of ESA's Rosetta spacecraft, to measure directly the forces and moments at the spacecraft/launch-vehicle interface. It proved extremely useful in ensuring that the test levels required by the launcher authorities were strictly applied, and that the tests were executed safely.

Salvignol, J.-C.; Brunner, O.

2001-02-01

231

Time resolved neutron yield measurements on FT device  

Microsoft Academic Search

A system of four BF3 proportional chambers for time resolved neutron yield measurements is operative on the FT (Frascati Torus) device. The determination of plasma parameters from neutron yield measurements is a relatively new field of investigation subjected to continuous improvements, also in view of feasible application to the control of future fusion reactors. The absolute calibration of neutron detectors

S. Podda

1987-01-01

232

Non-intrusive temperature measurement using microscale visualization techniques  

NASA Astrophysics Data System (ADS)

?PIV is a widely accepted tool for making accurate measurements in microscale flows. The particles that are used to seed the flow, due to their small size, undergo Brownian motion which adds a random noise component to the measurements. Brownian motion introduces an undesirable error in the velocity measurements, but also contains valuable temperature information. A PIV algorithm which detects both the location and broadening of the correlation peak can measure velocity as well as temperature simultaneously using the same set of images. The approach presented in this work eliminates the use of the calibration constant used in the literature (Hohreiter et al. in Meas Sci Technol 13(7):1072-1078, 2002), making the method system-independent, and reducing the uncertainty involved in the technique. The temperature in a stationary fluid was experimentally measured using this technique and compared to that obtained using the particle tracking thermometry method and a novel method, low image density PIV. The method of cross-correlation PIV was modified to measure the temperature of a moving fluid. A standard epi-fluorescence ?PIV system was used for all the measurements. The experiments were conducted using spherical fluorescent polystyrene-latex particles suspended in water. Temperatures ranging from 20 to 80C were measured. This method allows simultaneous non-intrusive temperature and velocity measurements in integrated cooling systems and lab-on-a-chip devices.

Chamarthy, Pramod; Garimella, Suresh V.; Wereley, Steven T.

2009-07-01

233

Method and apparatus for optical temperature measurements  

DOEpatents

A method and apparatus are provided for remotely monitoring temperature. Both method and apparatus employ a temperature probe material having an excitation-dependent emission line whose fluorescence intensity varies directly with temperature whenever excited by light having a first wavelength and whose fluorescence intensity varies inversely with temperature whenever excited by light having a second wavelength. Temperature is measured by alternatively illuminating the temperature probe material with light having the first wavelength and light having the second wavelength, monitoring the intensity of the successive emissions of the excitation-dependent emission line, and relating the intensity ratio of successive emissions to temperature.

Angel, S. Michael (Livermore, CA); Hirschfeld, Tomas B. (Livermore, CA)

1988-01-01

234

Method and apparatus for optical temperature measurements  

DOEpatents

A method and apparatus are provided for remotely monitoring temperature. Both method and apparatus employ a temperature probe material having an excitation-dependent emission line whose fluorescence intensity varies directly with temperature whenever excited by light having a first wavelength and whose fluorescence intensity varies inversely with temperature whenever excited by light having a second wavelength. Temperature is measured by alternatively illiminating the temperature probe material with light having the first wavelength and light having the second wavelength, monitoring the intensity of the successive emissions of the excitation-dependent emission line, and relating the intensity ratio of successive emissions to temperature. 3 figs.

Angel, S.M.; Hirschfeld, T.B.

1986-04-22

235

Small embedded sensors for accurate temperature measurements in DMOS power transistors  

Microsoft Academic Search

Device temperature is one of the most important limits for the safe operating area and the reliability of power DMOS transistors. Therefore, accurate measurements of their intrinsic device temperature are required. However, standard methods such as IR thermography usually cannot be applied to advanced smart power technologies where a thick power metal layer obscures the - often significantly hotter -

Martin Pfost; D. Costachescu; A. Podgaynaya; M. Stecher; S. Bychikhin; D. Pogany; E. Gornik

2010-01-01

236

Methods of Measurement for Semiconductor Materials, Process Control, and Devices  

NASA Technical Reports Server (NTRS)

The development of methods of measurement for semiconductor materials, process control, and devices is reported. Significant accomplishments include: (1) Completion of an initial identification of the more important problems in process control for integrated circuit fabrication and assembly; (2) preparations for making silicon bulk resistivity wafer standards available to the industry; and (3) establishment of the relationship between carrier mobility and impurity density in silicon. Work is continuing on measurement of resistivity of semiconductor crystals; characterization of generation-recombination-trapping centers, including gold, in silicon; evaluation of wire bonds and die attachment; study of scanning electron microscopy for wafer inspection and test; measurement of thermal properties of semiconductor devices; determination of S-parameters and delay time in junction devices; and characterization of noise and conversion loss of microwave detector diodes.

Bullis, W. M. (ed)

1973-01-01

237

Method and apparatus for optical temperature measurement  

DOEpatents

A temperature probe and a method for using said probe for temperature measurements based on changes in light absorption by the probe are disclosed. The probe comprises a first and a second optical fiber that carry light to and from the probe, and a temperature sensor material, the absorbance of which changes with temperature, through which the light is directed. Light is directed through the first optical fiber, passes through the temperature sensor material, and is transmitted by a second optical fiber from the material to a detector. Temperature-dependent and temperature-independent factors are derived from measurements of the transmitted light intensity. For each sensor material, the temperature T is a function of the ratio, R, of these factors. The temperature function f(R) is found by applying standard data analysis techniques to plots of T versus R at a series of known temperatures. For a sensor having a known temperature function f(R) and known characteristic and temperature-dependent factors, the temperature can be computed from a measurement of R. Suitable sensor materials include neodymium-doped borosilicate glass, accurate to [+-]0.5 C over an operating temperature range of about [minus]196 C to 400 C; and a mixture of D[sub 2]O and H[sub 2]O, accurate to [+-]0.1 C over an operating range of about 5 C to 90 C. 13 figs.

O'Rourke, P.E.; Livingston, R.R.; Prather, W.S.

1994-09-20

238

Method and apparatus for optical temperature measurement  

DOEpatents

A temperature probe and a method for using said probe for temperature measurements based on changes in light absorption by the probe. The probe comprises a first and a second optical fiber that carry light to and from the probe, and a temperature sensor material, the absorbance of which changes with temperature, through which the light is directed. Light is directed through the first optical fiber, passes through the temperature sensor material, and is transmitted by a second optical fiber from the material to a detector. Temperature-dependent and temperature-independent factors are derived from measurements of the transmitted light intensity. For each sensor material, the temperature T is a function of the ratio, R, of these factors. The temperature function f(R) is found by applying standard data analysis techniques to plots of T versus R at a series of known temperatures. For a sensor having a known temperature function f(R) and known characteristic and temperature-dependent factors, the temperature can be computed from a measurement of R. Suitable sensor materials include neodymium-doped boresilicate glass, accurate to .+-.0.5.degree. C. over an operating temperature range of about -196.degree. C. to 400.degree. C.; and a mixture of D.sub.2 O and H.sub.2 O, accurate to .+-.0.1.degree. C. over an operating range of about 5.degree. C. to 90.degree. C.

O'Rourke, Patrick E. (Martinez, GA); Livingston, Ronald R. (Aiken, SC); Prather, William S. (Augusta, GA)

1994-01-01

239

Highly temperature-dependent performance of a polyvinylidene fluoride Lamb wave device  

NASA Astrophysics Data System (ADS)

A Lamb wave device using a polyvinylidene flouride film is described. The transducer of the device consists of interdigital electrodes and a uniform counter-electrode. The performance of the device is highly temperature dependent. The attenuation of the Lamb wave on the film increases with higher frequencies. The attenuation decreases with increasing temperature, while the conversion efficiency of the transducer is nearly constant for the temperature change. The output of the device changes significantly under the influence of irradiation from a black body, and the device is very sensitive in the infrared region.

Toda, Kohji; Ikenohira, Kazuo

1980-11-01

240

Measuring Moduli Of Elasticity At High Temperatures  

NASA Technical Reports Server (NTRS)

Shorter, squatter specimens and higher frequencies used in ultrasonic measurement technique. Improved version of piezo-electric ultrasonic composite oscillator technique used to measure moduli of elasticity of solid materials at high temperatures.

Wolfenden, Alan

1993-01-01

241

Development of a magnetic measurement device for thin ribbon samples  

NASA Astrophysics Data System (ADS)

This paper presents a magnetic measurement device for thin ribbon samples, which are produced by rapid cooling technique. This device enables us to measure magnetic properties easily by only inserting a ribbon sample into a sample holder. The sample holder was made by bakelite to fix any width sample. A long solenoid coil was used to generate a uniform magnetic field and the sample holder was placed at the mid part of the solenoid. The magnetic field strength was measured using a shunt resistor and the magnetic flux density and magnetization in sample ribbons were evaluated by using search coils. The accuracy of measurement was verified with an amorphous metal ribbon sample. Next, we have measured magnetic properties of some magnetic shape memory alloys, which have different compositions. The measured results are compared and we clarified the effect of Sm contents on the magnetic properties.

Sato, Yuta; Todaka, Takashi; Enokizono, Masato

242

Minimizing noise-temperature measurement errors  

NASA Technical Reports Server (NTRS)

An analysis of noise-temperature measurement errors of low-noise amplifiers was performed. Results of this analysis can be used to optimize measurement schemes for minimum errors. For the cases evaluated, the effective noise temperature (Te) of a Ka-band maser can be measured most accurately by switching between an ambient and a 2-K cooled load without an isolation attenuator. A measurement accuracy of 0.3 K was obtained for this example.

Stelzried, C. T.

1992-01-01

243

Use of piezoelectric multicomponent force measuring devices in fluid mechanics  

NASA Technical Reports Server (NTRS)

The characterisitics of piezoelectric multicomponent transducers are discussed, giving attention to the advantages of quartz over other materials. The main advantage of piezoelectric devices in aerodynamic studies is their ability to indicate rapid changes in the values of physical parameters. Problems in the accuracy of measurments by piezoelectric devices can be overcome by suitable design approaches. A practical example is given of how such can be utilized to measure rapid fluctuations of fluid forces exerted on a circular cylinder mounted in a water channel.

Richter, A.; Stefan, K.

1979-01-01

244

Measurement of neutron flux from a tokamak plasma device  

NASA Astrophysics Data System (ADS)

A system has been developed for neutron flux measurements at the ORMAK tohamak device. This system allows measurement of the time-dependence of the neutron flux during a single shot of the device as well as the energy spectrum of the neutrons. Pulse shape discrimination techniques are used with a liquid scintillation counter (NE 213) to eliminate events in the detector due to gamma rays and X-rays generated in the plasma. Results are presented for the mode in which neutral deuterium is injected into a deuterium plasma.

Morgan, G. L.; England, A. C.

1975-11-01

245

Advances in turbine blade temperature measurements  

NASA Technical Reports Server (NTRS)

Radiation pyrometry principles and imaging methods like photography and photoelectric scanning are combined to make accurate research quality temperature measurements on turbine airfoils. Two systems are described for obtaining detailed temperature distribution measurements: an infrared photographic system for stationary vanes and a photoelectric scanning system for rotating blades. An overview is presented outlining the design, calibration methods, and recent test results.

Pollack, F. G.

1976-01-01

246

Magnetic Resonance Flow Velocity and Temperature Mapping of a Shape Memory Polymer Foam Device  

SciTech Connect

Interventional medical devices based on thermally responsive shape memory polymer (SMP) are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI) techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.

Small IV, W; Gjersing, E; Herberg, J L; Wilson, T S; Maitland, D J

2008-10-29

247

Calibration and correction of the device measuring magnetic gradient tensor  

NASA Astrophysics Data System (ADS)

Generally, four three-axis magnetometers (TAMs) are used to measure magnetic gradient tensor. But the measurement precision of magnetic gradient tensor is tightly connected with the imperfect performance of sensors such as non-orthogonality, different scale factors and biases among sensitive axes, misalignment between different TAMs. It is necessary to calibrate and correct the measurement device to obtain precise magnetic gradient tensor. A mathematical model for calibration of the device measuring magnetic gradient tensor is established, and the calibration algorithm and its steps based on functional link artificial neural network (FLANN) and least-squares method (LSM) are proposed. The numerical simulations prove the effectiveness and good convergence of calibration algorithm, which can improve remarkably the measurement precision of magnetic gradient tensor.

Huang, Yu; Wu, Li-hua

248

High-accuracy direct ZT and intrinsic properties measurement of thermoelectric couple devices  

NASA Astrophysics Data System (ADS)

Advances in thermoelectric materials in recent years have led to significant improvements in thermoelectric device performance and thus, give rise to many new potential applications. In order to optimize a thermoelectric device for specific applications and to accurately predict its performance ideally the material's figure of merit ZT as well as the individual intrinsic properties (Seebeck coefficient, electrical resistivity, and thermal conductivity) should be known with high accuracy. For that matter, we developed two experimental methods in which the first directly obtains the ZT and the second directly measures the individual intrinsic leg properties of the same p/n-type thermoelectric couple device. This has the advantage that all material properties are measured in the same sample direction after the thermoelectric legs have been mounted in the final device. Therefore, possible effects from crystal anisotropy and from the device fabrication process are accounted for. The Seebeck coefficients, electrical resistivities, and thermal conductivities are measured with differential methods to minimize measurement uncertainties to below 3%. The thermoelectric couple ZT is directly measured with a differential Harman method which is in excellent agreement with the calculated ZT from the individual leg properties. The errors in both the directly measured and calculated thermoelectric couple ZT are below 5% which is significantly lower than typical uncertainties using commercial methods. Thus, the developed technique is ideal for characterizing assembled couple devices and individual thermoelectric materials and enables accurate device optimization and performance predictions. We demonstrate the methods by measuring a p/n-type thermoelectric couple device assembled from commercial bulk thermoelectric Bi2Te3 elements in the temperature range of 30 C-150 C and discuss the performance of the couple thermoelectric generator in terms of its efficiency and materials' self-compatibility.

Kraemer, D.; Chen, G.

2014-04-01

249

High-accuracy direct ZT and intrinsic properties measurement of thermoelectric couple devices.  

PubMed

Advances in thermoelectric materials in recent years have led to significant improvements in thermoelectric device performance and thus, give rise to many new potential applications. In order to optimize a thermoelectric device for specific applications and to accurately predict its performance ideally the material's figure of merit ZT as well as the individual intrinsic properties (Seebeck coefficient, electrical resistivity, and thermal conductivity) should be known with high accuracy. For that matter, we developed two experimental methods in which the first directly obtains the ZT and the second directly measures the individual intrinsic leg properties of the same p/n-type thermoelectric couple device. This has the advantage that all material properties are measured in the same sample direction after the thermoelectric legs have been mounted in the final device. Therefore, possible effects from crystal anisotropy and from the device fabrication process are accounted for. The Seebeck coefficients, electrical resistivities, and thermal conductivities are measured with differential methods to minimize measurement uncertainties to below 3%. The thermoelectric couple ZT is directly measured with a differential Harman method which is in excellent agreement with the calculated ZT from the individual leg properties. The errors in both the directly measured and calculated thermoelectric couple ZT are below 5% which is significantly lower than typical uncertainties using commercial methods. Thus, the developed technique is ideal for characterizing assembled couple devices and individual thermoelectric materials and enables accurate device optimization and performance predictions. We demonstrate the methods by measuring a p/n-type thermoelectric couple device assembled from commercial bulk thermoelectric Bi2Te3 elements in the temperature range of 30?C-150?C and discuss the performance of the couple thermoelectric generator in terms of its efficiency and materials' self-compatibility. PMID:24784659

Kraemer, D; Chen, G

2014-04-01

250

Optical temperature measurements of silicon microbridge emitters.  

PubMed

Microbridges are miniature suspended structures fabricated in silicon. Passing a current through the microbridge can heat it up to the point of incandescence. A glowing microbridge can be used as a wideband light source. This study presents a method for optical measurement of the temperature of a microbridge. Spectroscopic measurements of microbridges are optically challenging, because the multilayer structures cause interference effects. To determine the temperature from the emitted spectrum, the emissivity was modeled with thin-film Fresnel equations. Temperatures of 500-1100 degrees C were obtained from the measured spectra at different levels of applied power. The range is limited by the sensitivity of the detectors at lower power levels and by the stability of the bridge at higher levels. Results of the optical measurements were compared with contact temperature measurements made with a microthermocouple in the same temperature range. The results of the two methods agree within 100 K. PMID:20300142

Shpak, Maksim; Sainiemi, Lauri; Ojanen, Maija; Krh, Petri; Heinonen, Martti; Franssila, Sami; Ikonen, Erkki

2010-03-20

251

Submicron measurements of domain wall dynamics in patterned (Ga,Mn)As devices  

NASA Astrophysics Data System (ADS)

Contemporary interest in proof-of-concept semiconductor spintronic devices provides a clear motivation for fundamental studies of magnetic domain walls (DWs) in ferromagnetic semiconductors such as (Ga,Mn)As. Here, we use the anomalous Hall effect to measure the magnetic DW position and velocity in micropatterned (Ga,Mn)As devices with submicron spatial resolution. Our measurements focus on the early stages of the creep regime. Statistical analysis of temperature-dependent Barkhausen jumps provides insights into thermally activated DW hopping, while field-dependent measurements of the DW position show behavior suggestive of reversible nanoscale DW flexing. Finally, we demonstrate a feedback technique to map out submicron variations in the DW pinning potential. These measurements are complemented by dynamic magneto-optical Kerr effect imaging of our devices. This work was supported by ONR, NSF and ONR-MURI.

Balk, A. L.; Wilson, M. J.; Rench, D.; Schiffer, P.; Samarth, N.; Nowakowski, M.; Awschalom, D. D.

2010-03-01

252

A survey of gas-side fouling measuring devices  

NASA Technical Reports Server (NTRS)

A survey of measuring devices or probes, which were used to investigate gas side fouling, was carried out. Five different types of measuring devices are identified and discussed including: heat flux meters, mass accumulation probes, optical devices, deposition probes, and acid condensation probes. A total of 32 different probes are described in detail and summarized in matrix or tabular form. The important considerations of combustion gas characterization and deposit analysis are also given a significant amount of attention. The results show that considerable work was done in the development of gas side fouling probes. However, it is clear that the design, construction, and testing of a durable, versatile probe - capable of monitoring on-line fouling resistances - remains a formidable task.

Marner, W. J.; Henslee, S. P.

1984-01-01

253

Temperature Sensitive Particle for Velocity and Temperature Measurement.  

NASA Astrophysics Data System (ADS)

Phosphorescence and fluorescence are often applied to measure the temperature and the concentration of oxygen. The intensity and the lifetime of phosphor depend on the temperature and the oxygen concentration, due to the quenching effect of the phosphor. The present study clarified the effects of temperature on the lifetime of phosphorescence of Porphyrins, Ru(bpy)3^2+ and the europium complex. The phosphorescence lifetime of oil solution / water solution / painted wall were measured with changing temperature and oxygen concentration. In addition, the optical property of the small particles incorporated with the europium complex was investigated in the oil/water. The lifetime was strongly affected by temperature. Then, the temperature sensitive particle (TSParticle) with metal complex was applied to measure temperature in Silicone oil (10cSt) two-dimensionally. Present study is the result of ?High speed three-dimensional direct measurement technology development for the evaluation of heat flux and flow of liquid metal? entrusted to the University of Tokyo by the Ministry of Education, Culture, Sports, Science and Technology of Japan(MEXT).

Someya, Satoshi; Okamoto, Koji; Iida, Masao

2007-11-01

254

Method and apparatus for measuring low currents in capacitance devices  

DOEpatents

A method and apparatus for measuring subnanoampere currents in capacitance devices is reported. The method is based on a comparison of the voltages developed across the capacitance device with that of a reference capacitor in which the current is adjusted by means of a variable current source to produce a stable voltage difference. The current varying means of the variable current source is calibrated to provide a read out of the measured current. Current gain may be provided by using a reference capacitor which is larger than the device capacitance with a corresponding increase in current supplied through the reference capacitor. The gain is then the ratio of the reference capacitance to the device capacitance. In one illustrated embodiment, the invention makes possible a new type of ionizing radiation dose-rate monitor where dose-rate is measured by discharging a reference capacitor with a variable current source at the same rate that radiation is discharging an ionization chamber. The invention eliminates high-megohm resistors and low current ammeters used in low-current measuring instruments.

Kopp, M.K.; Manning, F.W.; Guerrant, G.C.

1986-06-04

255

IN SITU FIELD PORTABLE FINE PARTICLE MEASURING DEVICE  

EPA Science Inventory

The report describes the design, development, and testing of an in situ fine particle measuring device--the Fine Particle Stack Spectrometer System (FPSSS). It is a laser-fed optical system with detection by near-forward light scattering. Sample volume is established by a high-re...

256

In situ Field Portable Fine Particle Measuring Device.  

National Technical Information Service (NTIS)

The report describes the design, development, and testing of an in situ fine particle measuring device--the Fine Particle Stack Spectrometer System (FPSSS). It is a laser-fed optical system with detection by near-forward light scattering. Sample volume is...

R. G. Knollenberg

1984-01-01

257

Barium strontium titanate thin film varactors for room-temperature microwave device applications  

Microsoft Academic Search

Recent progress in the development of barium strontium titanate thin film varactors for room temperature tunable microwave devices applications is reviewed, with emphasis on efforts towards the improvement in the quality of BST thin films and the fabrication issues crucial for the performance of microwave devices based on BST varactors. The paper provides examples of tunable microwave devices employing BST

P Bao; T J Jackson; X Wang; M J Lancaster

2008-01-01

258

Nulling Infrared Radiometer for Measuring Temperature  

NASA Technical Reports Server (NTRS)

A nulling, self-calibrating infrared radiometer is being developed for use in noncontact measurement of temperature in any of a variety of industrial and scientific applications. This instrument is expected to be especially well-suited to measurement of ambient or near-ambient temperature and, even more specifically, for measuring the surface temperature of a natural body of water. Although this radiometer would utilize the long-wavelength infrared (LWIR) portion of the spectrum (wavelengths of 8 to 12 m), its basic principle of operation could also be applied to other spectral bands (corresponding to other temperature ranges) in which the atmosphere is transparent and in which design requirements for sensitivity and temperature-measurement accuracy could be satisfied.

Ryan, Robert

2003-01-01

259

Heated body temperature measurement by spectrometry of photoelectrons  

NASA Astrophysics Data System (ADS)

It is shown that the heated body temperature can be measured from the energy distribution of photoelectrons appearing in the photoelectric device which serves simultaneously as detector and analyser of the body radiation spectrum. The effective wavelengths of this temperature measuring technique cannot be chosen arbitrarily because they are functions of the temperature and must be measured. A technique for measuring the series of values of the effective wavelengths 0957-0233/9/9/005/img1, which is necessary for estimation of the procedural error 0957-0233/9/9/005/img2, has been proposed. The latter depends on the type of spectral characteristic of the photodetector, the energy photoelectron dispersion D in a retarding field and the emissivity of a heated surface 0957-0233/9/9/005/img3. The formulae for the procedural error calculation are obtained and the latter has been shown to be less than that for measuring the temperature by conventional optical pyrometry methods and almost independent of temperature; 0957-0233/9/9/005/img4-3 K for tungsten (when T = 1200-2600 K) and 0957-0233/9/9/005/img5-5 K for platinum (when T = 1200-1800 K). The calculated results have been proved by series of experiments. A photoemissive pyrometer based on this method can be employed for temperature measurements when the exact meaning of a changeable emissivity is unknown as it takes place, for example, at pulse heating processes.

Kasparov, K. N.

1998-09-01

260

Design fabrication and installation of a yaw measuring device  

NASA Technical Reports Server (NTRS)

The results of work performed in the development and testing of a yaw measuring device are summarized. A review of the yaw measurement method; and the techniques and hardware needed for its implementation are presented. A description and summary of the tests performed at the U.S. Bureau of Mines Bruceton facility are included. Conclusions are summarized and recommendations for a unit capable of operation in a mine environment are presented.

1979-01-01

261

PV device performance calculations from measured indoor and outdoor spectra  

SciTech Connect

Outdoor solar spectra and spectra of both arcdischarge and filament-type solar simulators have been measured. Short-circuit currents were calculated using these spectra and the measured spectral response data of four different photovoltaic devices. The results show a significant dependence on spectral content of the illuminating sources. The importance of good spectroradiometer design, frequent calibrations, performance testing, and proper operating procedures is emphasized.

Cannon T.W.; Hulstrom, R.L.; Riordan, C.J.

1984-05-01

262

Assembly for electrical conductivity measurements in the piston cylinder device  

DOEpatents

An assembly apparatus for measurement of electrical conductivity or other properties of a sample in a piston cylinder device wherein pressure and heat are applied to the sample by the piston cylinder device. The assembly apparatus includes a body, a first electrode in the body, the first electrode operatively connected to the sample, a first electrical conductor connected to the first electrode, a washer constructed of a hard conducting material, the washer surrounding the first electrical conductor in the body, a second electrode in the body, the second electrode operatively connected to the sample, and a second electrical conductor connected to the second electrode.

Watson, Heather Christine (Dublin, CA); Roberts, Jeffrey James (Livermore, CA)

2012-06-05

263

Methods for measuring acoustic power of an ultrasonic neurosurgical device.  

PubMed

Measurement of the acoustic power in high-energy ultrasonic devices is complex due to occurrence of the strong cavitation in front of the sonotrode tip. In our research we used three methods for characterization of our new ultrasonic probe for neuroendoscopic procedures. The first method is based on the electromechanical characterization of the device measuring the displacement of the sonotrode tip and input electrical impedance around excitation frequency with different amounts of the applied electrical power The second method is based on measuring the spatial pressure magnitude distribution of an ultrasound surgical device produced in an anechoic tank. The acoustic reciprocity principle is used to determinate the derived acoustic power of equivalent ultrasound sources at frequency components present in the spectrum of radiated ultrasonic waves. The third method is based on measuring the total absorbed acoustic power in the restricted volume of water using the calorimetric method. In the electromechanical characterization, calculated electroacoustic efficiency factor from equivalent electrical circuits is between 40-60%, the same as one obtained measuring the derived acoustic power in an anechoic tank when there is no cavitation. When cavitation activity is present in the front of the sonotrode tip the bubble cloud has a significant influence on the derived acoustic power and decreases electroacoustic efficiency. The measured output acoustic power using calorimetric method is greater then derived acoustic power, due to a large amount of heat energy released in the cavitation process. PMID:21648319

Petosi?, Antonio; Ivancevi?, Bojan; Svilar, Dragoljub; Stimac, Tihomir; Paladino, Josip; Oreskovi?, Darko; Jurjevi?, Ivana; Klarica, Marijan

2011-01-01

264

Surface temperature measurement of turbine disks  

NASA Astrophysics Data System (ADS)

A new method of temperature measurement with a single-wire thermocouple - slip ring system is introduced to measure the surface temperature of the turbine disks in the turbojet engines, and the accuracy of this method is considered. In this case, the limited channels of the slip ring are fully utilized and the measured surface temperatures of the disk are actual and believable enough. The problems in its application, such as the installation of the thermocouples, the cooling of the slip ring, and the balance of the turbine rotor with this system, are discussed briefly.

Wu, Hongdao; Qu, Yuwu; Li, Xungguang; Du, Shengqin

1993-01-01

265

Methods of measurement for semiconductor materials, process control, and devices  

NASA Technical Reports Server (NTRS)

Significant accomplishments include development of a procedure to correct for the substantial differences of transistor delay time as measured with different instruments or with the same instrument at different frequencies; association of infrared response spectra of poor quality germanium gamma ray detectors with spectra of detectors fabricated from portions of a good crystal that had been degraded in known ways; and confirmation of the excellent quality and cosmetic appearance of ultrasonic bonds made with aluminum ribbon wire. Work is continuing on measurement of resistivity of semiconductor crystals; study of gold-doped silicon, development of the infrared response technique; evaluation of wire bonds and die attachment; and measurement of thermal properties of semiconductor devices, delay time and related carrier transport properties in junction devices, and noise properties of microwave diodes.

Bullis, W. M. (editor)

1972-01-01

266

Implementation of a measurement-device-independent entanglement witness.  

PubMed

Entanglement, the essential resource in quantum information processing, should be witnessed in many tasks such as quantum computing and quantum communication. The conventional entanglement witness method, relying on an idealized implementation of measurements, could wrongly conclude a separable state to be entangled due to imperfect detections. Inspired by the idea of a time-shift attack, we construct an attack on the conventional entanglement witness process and demonstrate that a separable state can be falsely identified to be entangled. To close such detection loopholes, based on a recently proposed measurement-device-independent entanglement witness method, we design and experimentally demonstrate a measurement-device-independent entanglement witness for a variety of two-qubit states. By the new scheme, we show that an entanglement witness can be realized without detection loopholes. PMID:24765936

Xu, Ping; Yuan, Xiao; Chen, Luo-Kan; Lu, He; Yao, Xing-Can; Ma, Xiongfeng; Chen, Yu-Ao; Pan, Jian-Wei

2014-04-11

267

Dynamic temperature measurements with embedded optical sensors.  

SciTech Connect

This report summarizes LDRD project number 151365, %5CDynamic Temperature Measurements with Embedded Optical Sensors%22. The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.

Dolan, Daniel H.,; Seagle, Christopher T; Ao, Tommy

2013-10-01

268

Determination of annealing of temperature HfO2/Si metal-oxide-semiconductor devices  

NASA Astrophysics Data System (ADS)

Thermal behavior of thin high-k dielectric films ( 8.4 nm) of HfO2, deposited by reactive rf-sputtering technique on n-type Si (100) wafer, is studied by thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) techniques. DSC results reflect partial crystallization of the film which starts at 250 C and another transformation begins beyond 670 C. The high-frequency (HF) capacitance - voltage (C-V) characteristics, measured for all the devices, annealed at different temperatures also corroborate the above observation.

Biswas, Debaleen; Faruque, Sk. Abdul Kader Md.; Chakraborty, Supratic

2014-04-01

269

NaOH-based high temperature heat-of-fusion thermal energy storage device  

NASA Technical Reports Server (NTRS)

A material called Thermkeep, developed as a low-cost method for the storage of thermal energy for solar electric power generating systems is discussed. The storage device consists of an insulated cylinder containing Thermkeep in which coiled tubular heat exchangers are immersed. A one-tenth scale model of the design contains 25 heat-exchanger tubes and 1500 kg of Thermkeep. Its instrumentation includes thermocouples to measure internal Thermkeep temperatures, vessel surface, heated shroud surface, and pressure gauges to indicate heat-exchanger pressure drops. The test-circuit design is presented and experimental results are discussed.

Cohen, B. M.; Rice, R. E.

1978-01-01

270

Constant frequency pulsed phase-locked loop measuring device  

NASA Technical Reports Server (NTRS)

A measuring apparatus is presented that uses a fixed frequency oscillator to measure small changes in the phase velocity ultrasonic sound when a sample is exposed to environmental changes such as changes in pressure, temperature, etc. The invention automatically balances electrical phase shifts against the acoustical phase shifts in order to obtain an accurate measurement of electrical phase shifts.

Yost, William T. (inventor); Kushnick, Peter W. (inventor); Cantrell, John H. (inventor)

1993-01-01

271

Comparison Measurements of Silicon Carbide Temperature Monitors  

Microsoft Academic Search

As part of a process initiated through the Advanced Test Reactor (ATR) National Scientific User Facility (NSUF) program to make Silicon Carbide (SiC) temperature monitors available for experiments, a capability was developed at the Idaho National Laboratory (INL) to complete post-irradiation evaluations of these monitors. INL selected the resistance measurement approach for detecting peak irradiation temperature from SiC temperature monitors.

Joy L. Rempe; Keith G. Condie; Darrell L. Knudson; Lance Lewis Snead

2010-01-01

272

Laser interferometric thermometry for substrate temperature measurement  

Microsoft Academic Search

This paper investigates a simple noncontact optical thermometry technique based on the laser interferometric measurement of the thermal expansion and refractive index change of a thin transparent substrate or temperature sensor. The technique is shown to be extendible from room temperature to at least 900 C with the proper choice of a thermally stable sensor. Sensor materials investigated included c-axis

Katherine L. Saenger; Julie Gupta

1991-01-01

273

POST-SHOCK TEMPERATURE MEASUREMENTS OF ALUMINUM  

Microsoft Academic Search

Post-shock temperature is an important quantity in shock physics experiments for constraining the dynamic equations of state of materials. A high-speed, infrared, multi-wavelength pyrometer has been developed at Los Alamos National Laboratory (LANL) for measurements in the temperature range from 400 to 1200 K. With customized front end optics, permitting concurrent VISAR measurements in the same optical path, validation experiments

A. Seifter; S. T. Stewart; M. R. Furlanetto; G. B. Kennedy; J. R. Payton

274

Measuring the temperature of microparticles in plasmas  

SciTech Connect

Temperature sensitive features of particular phosphors were utilized for measuring the temperature T{sub p} of microparticles, confined in the sheath of a rf plasma. The experiments were performed under variation of argon pressure and rf power of the process plasma. T{sub p} has been determined by evaluation of characteristic fluorescent lines. The results for T{sub p} measurements are strongly dependent on rf power and gas pressure.

Maurer, Horst; Basner, Ralf [INP Greifswald, Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany); Kersten, Holger [IEAP Kiel, Leibnizstr. 19, D-24098 Kiel (Germany)

2008-09-15

275

Calibrating X-ray Imaging Devices for Accurate Intensity Measurement  

SciTech Connect

The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.

Haugh, M. J.

2011-07-28

276

Performance measurements of multilayer insulation at variable cold temperature  

NASA Astrophysics Data System (ADS)

Multilayer insulation (MLI) is commonly used in most cryogenic devices such as LHe-cryostats or superconductive cables. Typically thermal performance measurements have been carried out using bath cryostats. Inherent to all this devices is a fixed cold temperature at the boiling point of the particular cryogenic liquid. A recent approach for cryogenic pressure vessels covers a broad temperature range, i.e. hydrogen storage from 20 K to ambient temperature. Thus, a new calorimeter cryostat has been designed at TU Dresden to meet these requirements. The design as a flow cryostat allows the measurement of the thermal performance with variable cold temperature between 20 K and 300 K. It can be operated in vertical as well as in horizontal orientation. The insulation material is wrapped around a nearly isothermal cylinder which is held at the desired temperature by a cooling fluid. Preferably LHe respectively helium cold gas is used. Several design features reduce undesired interference errors. It is reported about design and equipment of this cryostat plus first experiences in operation

Funke, Thomas; Haberstroh, Christoph

2012-06-01

277

Low-temperature thermoelectric refrigerating device using current-carrying superconducting mode\\/nonsuperconducting mode junctions  

Microsoft Academic Search

This patent describes a refrigerating device that produces cooling below a preselected temperature. It comprises: a heat sink operable to produce the preselected temperature; a refrigerating unit, including a first piece of a first material that is electrically conducting but not superconducting at the preselected temperature, a second piece of a second material that is superconducting at the preselected temperature,

Skertic

1991-01-01

278

A Microwave Radiometer for Internal Body Temperature Measurement  

NASA Astrophysics Data System (ADS)

This thesis presents the analysis and design of a microwave radiometer for internal body temperature measurements. There is currently no available method for non-invasive temperature measurement inside the human body. However, knowledge of both relative and absolute temperature variations over time is important to a number of medical applications. The research presented in this thesis details a proof-of-concept near-field microwave radiometer demonstrating relative thermometry of a multi-layer phantom. There are a number of technical challenges addressed in this thesis for radiometric determination of sub-degree temperature variations in the human body. A theoretical approach is developed for determining sensing depth from known complex layered tissues, which is defined as a figure of merit, and is shown to be dependent on frequency, electrical properties of the tissues, and the near-field probe. In order to obtain depth resolution, multiple frequency operation can be used, so multi-frequency probes are designed and demonstrated in this work. The choice of frequencies is determined not only by the tissue material properties, but also by the ever increasing radio interference in the environment. In this work, quiet bands allocated to radio astronomy are investigated. The radiometer and probe need to be compact to be wearable, and several advancements are made towards a fully wearable device: multi-frequency low-profile probes are designed and fabricated on a flexible substrate and the process of on-chip integration is demonstrated by a GaAs MMIC cold noise source for radiometer calibration. The implemented proof-of-concept device consists of two radiometers at 1.4 GHz and 2.7 GHz, designed with commercial inexpensive devices that can enable sufficient sensitivity. The device is tested on a phantom with two water layers whose temperatures are varied in a controlled manner, and focused on the human body temperature range. Measured results are discussed qualitatively as they relate to circadian rhythm monitoring. Finally, the thesis identifies future research that is required to make a practical wearable microwave thermometer for internal body temperature measurements.

Scheeler, Robert Patterson

279

Measuring transient temperatures in brake rotors  

SciTech Connect

A vehicle's kinetic energy is converted into thermal energy when its brakes are applied. If this energy is dissipated in the disc rotor, it can cause local temperature rises which induce disc distortions. Although analysis of this thermal phenomenon has been attempted by several means, a study of the transient temperature distribution has not been made due to the difficulty of measuring it by conventional means. The system to be discussed in this article makes non-contact measurement possible even in a narrow space. Temperature distribution patterns during a revolution of high speed braking can be determined for both sides of a disc rotor.

Idogaki, T.; Kawai, H.; Harada, H.; Inoune, H.

1987-06-01

280

Floating Probe Assembly for Measuring Temperature of Water  

NASA Technical Reports Server (NTRS)

A floating apparatus denoted a temperature probe aquatic suspension system (TPASS) has been developed for measuring the temperature of an ocean, lake, or other natural body of water at predetermined depths. Prior instruments built for the same purpose were found to give inaccurate readings because the apparatuses themselves significantly affected the temperatures of the water in their vicinities. The design of the TPASS is intended to satisfy a requirement to minimize the perturbation of the temperatures to be measured. The TPASS includes a square-cross-section aluminum rod 28 in. (=71 cm) long with floats attached at both ends. Each float includes five polystyrene foam disks about 3/4 in.(=1.9 cm) thick and 2.5 in. (=6.4 cm) in diameter. The disks are stacked to form cylinders, bolted to the rod, and covered with hollow plastic sleeves. A metal sleeve is clamped to the middle of the aluminum rod, from whence it hangs down into the water. Temperature probes (which can be thermocouples, thermistors, or resistance temperature devices) are placed within the sleeve at the desired measurement depths. Wires from the temperature probes are routed to the input terminals of a data logger.

Stewart, Randy; Ruffin, Clyde

2002-01-01

281

Floating Probe Assembly for Measuring Temperature of Water  

NASA Technical Reports Server (NTRS)

A floating apparatus denoted a temperature probe aquatic suspension system (TPASS) has been developed for measuring the temperature of an ocean, lake, or other natural body of water at predetermined depths. Prior instruments built for the same purpose were found to give inaccurate readings because the apparatuses themselves significantly affected the temperatures of the water in their vicinities. The design of the TPASS is intended to satisfy a requirement to minimize the perturbation of the temperatures to be measured. The TPASS includes a square-cross-section aluminum rod 28 in. (approx. = 71 cm) long with floats attached at both ends. Each float includes five polystyrene foam disks about 3/4 in. (approx. = 1.9 cm) thick and 2.5 in. (approx. = 6.4 cm) in diameter. The disks are stacked to form cylinders, bolted to the rod, and covered with hollow plastic sleeves. A metal sleeve is clamped to the middle of the aluminum rod, from whence it hangs down into the water. Temperature probes (which can be thermocouples, thermistors, or resistance temperature devices) are placed within the sleeve at the desired measurement depths. Wires from the temperature probes are routed to the input terminals of a data logger. This work was done by Randy

Selinsky, T.; Stewart, Randy; Ruffin, Clyde

2002-01-01

282

Measurement-device-independent quantum key distribution with quantum memories  

NASA Astrophysics Data System (ADS)

We generalize measurement-device-independent quantum key distribution [Lo, Curty, and Qi, Phys. Rev. Lett. 108, 130503 (2012), 10.1103/PhysRevLett.108.130503] to the scenario where the Bell-state measurement station contains also heralded quantum memories. We find analytical formulas, in terms of device imperfections, for all quantities entering in the secret key rates, i.e., the quantum bit error rate and the repeater rate. We assume either single-photon sources or weak coherent pulse sources plus decoy states. We show that it is possible to significantly outperform the original proposal, even in presence of decoherence of the quantum memory. Our protocol may represent the first natural step for implementing a two-segment quantum repeater.

Abruzzo, Silvestre; Kampermann, Hermann; Bru, Dagmar

2014-01-01

283

MISSE 1 and 2 Tray Temperature Measurements  

NASA Technical Reports Server (NTRS)

The Materials International Space Station Experiment (MISSE 1 & 2) was deployed August 10,2001 and retrieved July 30,2005. This experiment is a co-operative endeavor by NASA-LaRC. NASA-GRC, NASA-MSFC, NASA-JSC, the Materials Laboratory at the Air Force Research Laboratory, and the Boeing Phantom Works. The objective of the experiment is to evaluate performance, stability, and long term survivability of materials and components planned for use by NASA and DOD on future LEO, synchronous orbit, and interplanetary space missions. Temperature is an important parameter in the evaluation of space environmental effects on materials. The MISSE 1 & 2 had autonomous temperature data loggers to measure the temperature of each of the four experiment trays. The MISSE tray-temperature data loggers have one external thermistor data channel, and a 12 bit digital converter. The MISSE experiment trays were exposed to the ISS space environment for nearly four times the nominal design lifetime for this experiment. Nevertheless, all of the data loggers provided useful temperature measurements of MISSE. The temperature measurement system has been discussed in a previous paper. This paper presents temperature measurements of MISSE payload experiment carriers (PECs) 1 and 2 experiment trays.

Harvey, Gale A.; Kinard, William H.

2006-01-01

284

Integrated seal for high-temperature electrochemical device  

DOEpatents

The present invention provides electrochemical device structures having integrated seals, and methods of fabricating them. According to various embodiments the structures include a thin, supported electrolyte film with the electrolyte sealed to the support. The perimeter of the support is self-sealed during fabrication. The perimeter can then be independently sealed to a manifold or other device, e.g., via an external seal. According to various embodiments, the external seal does not contact the electrolyte, thereby eliminating the restrictions on the sealing method and materials imposed by sealing against the electrolyte.

Tucker, Michael C; Jacobson, Craig P

2013-07-16

285

Comparison Measurements of Silicon Carbide Temperature Monitors  

SciTech Connect

As part of the efforts initiated through the Advanced Test Reactor (ATR) National Scientific User Facility (NSUF) program to make Silicon Carbide (SiC) temperature monitors available, a capability was developed at the Idaho National Laboratory (INL) to complete post-irradiation evaluations of these monitors. INL selected the resistance measurement approach for detecting peak irradiation temperature from SiC temperature monitors. To demonstrate this new capability, comparison measurements were completed by INL and Oak Ridge National Laboratory (ORNL) on identical samples subjected to identical irradiation conditions. Results reported in this paper indicate that the resistance measurement approach can yield similar peak irradiation temperatures if appropriate equipment is used and appropriate procedures are followed.

J. L. Rempe; K. G. Condie; D. L. Knudson; L. L. Snead

2010-06-01

286

Electromagnetic device for measuring the integrity of long bones  

Microsoft Academic Search

Summary form only given. Monitoring the skeletal status is important for determining the effectiveness of treatment for osteoporosis. Computerized tomography, photon absorptiometry and DEXA are often used for monitoring the changes in bone mass and bone density. However, these techniques involve some radiation exposure to the patient. We have developed a non-invasive electro-magnetic device which can measure the cross-sectional geometry

S. Saha

2002-01-01

287

A wireless device for measuring hand-applied forces  

Microsoft Academic Search

We report on a wireless, electromyography (EMG)-based, force-measuring system developed to quantify hand-applied loads without interfering with grasping function. A portable surface EMG device detects and converts to voltage output biopotentials generated by muscle contractions in the forearm and upper arm during hand-gripping and traction activities. After amplifying and bandpass filtering, our radio frequency (RF)-based design operating at ?916 MHz

William Tam; Robert H. Allen; Y. S. G. Hoe; S. Huang; I.-J. Khoo; K. E. Outland; E. D. Gurewitsch

2004-01-01

288

An Algorithm for Express Temperature Measurement  

Microsoft Academic Search

Long time of measurement is a common disadvan? tage of most contemporary medical thermometers including digital thermometers based on conductive ther? mal exchange with the object of measurement. Specificity of a living organism as an object of temperature monitor? ing makes it difficult to solve this problem [1]. Let us con? sider modern approaches to solution of this problem. The

I. A. Dolgova; B. V. Chuvikin

2009-01-01

289

Accuracy analysis of the space shuttle solid rocket motor profile measuring device  

NASA Technical Reports Server (NTRS)

The Profile Measuring Device (PMD) was developed at the George C. Marshall Space Flight Center following the loss of the Space Shuttle Challenger. It is a rotating gauge used to measure the absolute diameters of mating features of redesigned Solid Rocket Motor field joints. Diameter tolerance of these features are typically + or - 0.005 inches and it is required that the PMD absolute measurement uncertainty be within this tolerance. In this analysis, the absolute accuracy of these measurements were found to be + or - 0.00375 inches, worst case, with a potential accuracy of + or - 0.0021 inches achievable by improved temperature control.

Estler, W. Tyler

1989-01-01

290

An AlN-based high temperature package for SiC devices: materials and processing  

Microsoft Academic Search

SiC-based electronics have the potential for reliable operations at higher junction temperatures, power densities, and frequencies than those can be achieved with Si devices. At present the development of SiC devices for use at temperatures up to 500C has been well underway for various applications. However, currently available packages are not capable of working at such high temperature. Therefore, it

Zhigang Lin; Rick J. Yoon

2005-01-01

291

a Low Noise High Temperature Superconducting Quantum Interference Device  

Microsoft Academic Search

Superconducting quantum interference devices (SQUIDs) are useful for a number of applications such as magnetometers, high speed samplers, and RF amplifiers. In some applications, the advantage of a superconducting system is not sufficient to justify 4.2 K operation. However, a high T _{rm c} implementation may be attractive. These active circuits demand Josephson junctions and other structures with tunable, well-understood

Alan Bruce Berezin

1993-01-01

292

A simple device for dielectric spectroscopy of polymers with temperature regulation close to 300 K based on a Peltier junction.  

PubMed

We present a simple thermostat device for performing dielectric spectroscopy measurements on polymers close to their glass transition temperature. By using a vacuum chamber containing a Peltier junction with its regulator, we show that a very simple setup yields a temperature accuracy which is good enough for accurate studies of polymer dielectric properties. This technique is also more cost effective than standard setups using cryogenic fluids. PMID:22559545

Raihane, A; Tourbot, R; Ladieu, F; L'Hte, D

2012-04-01

293

Methods of measurement for semiconductor materials, process control, and devices  

NASA Technical Reports Server (NTRS)

Activities directed toward the development of methods of measurement for semiconductor materials, process control, and devices are described. Topics investigated include: measurements of transistor delay time; application of the infrared response technique to the study of radiation-damaged, lithium-drifted silicon detectors; and identification of a condition that minimizes wire flexure and reduces the failure rate of wire bonds in transistors and integrated circuits under slow thermal cycling conditions. Supplementary data concerning staff, standards committee activities, technical services, and publications are included as appendixes.

Bullis, W. M. (editor)

1972-01-01

294

Adaptive Blood Glucose Monitoring and Insulin Measurement Devices for Visually Impaired Persons.  

ERIC Educational Resources Information Center

This article describes devices that people with visual impairments and diabetes can use to monitor blood glucose levels and measure insulin. A table lists devices, their manufacturers (including address and telephone number), and comments about the devices. (DB)

Petzinger, R. A.

1993-01-01

295

SiC device development for high temperature sensor applications  

NASA Technical Reports Server (NTRS)

Progress made in the processing and characterization of 3C-SiC for high temperature sensor applications is reviewed. Piezoresistance properties of silicon carbide and the temperature coefficient of resistivity of n-type beta-SiC are presented. In addition, photoelectrical etching and dopant selective etch-stops in SiC and high temperature Ohmic contacts for n-type beta-SiC sensors are discussed.

Shor, J. S.; Goldstein, David; Kurtz, A. D.; Osgood, R. M.

1992-01-01

296

Surface temperature measurement of plasma facing components with active pyrometry  

NASA Astrophysics Data System (ADS)

In fusion devices like ITER, plasma facing components will be in metal, (Tungsten and Beryllium), with emissivity in the range of 0.1-0.4. Therefore, surface temperature monitoring by infrared system will become more challenging due to low emissivity and consequently non negligible reflected flux. The active pyrometry method proposed in this paper allows surface temperature measurements independently of reflected and parasitic fluxes. A local increase of the surface temperature (?T(t)~10 C) introduced by a transient heating source (pulsed or modulated) results in an additional component of the flux collected by the detector. A filtering of the signal allows extracting a temporal flux proportional only to the variation of the emitted flux. The ratio of simultaneous measurements at two wavelengths allows solving the unknown emissivity (same as for classical bicolour pyrometry). In this paper, it is described how the active pyrometry method is adapted to the surface temperature measurements of metallic PFCs independently of the reflected fluxes. Experimental results for carbon and tungsten samples are reported. Finally, it is shown how, by using the active pyrometry, the overall 2D standard IR perturbed by a reflected flux is corrected to recover the full 2D surface temperature close to the real surface temperature.

Amiel, S.; Loarer, T.; Pocheau, C.; Roche, H.; Aumeunier, M. H.; Gauthier, E.; Le Niliot, C.; Rigollet, F.

2012-11-01

297

Semiconductor Junction Temperature Measurement using the Electron Beam Induced Current Mode in the Scanning Electron Miscroscope  

Microsoft Academic Search

A technique is described to accomplish junction temperature measurements in semiconductor devices in the scanning electron microscope. It details the procedure to produce high spatial resolution measurements and thermal gradient images of the true junction temperature. This approach combines the information in the electron beam induced current mode and the characteristic change in the forward voltage drop of a junction

Joseph M. Patterson

1984-01-01

298

Measurement of protection factor of respiratory protective devices toward nanoparticles.  

PubMed

The use of nanoparticles in industry has increased spectacularly over the past few years. Additionally, nanoscale particles seem to be the cause of new professional exposure situations. Due to their size, these particles may build up within the respiratory tract and may even reach the nervous system via the nasal passages; for this reason, it is generally recommended to wear respiratory protective devices (RPDs) in situations where collective protection is impossible to implement or inadequate. Here, we present the test bench ETNA designed to study the efficiency of RPDs in the presence of nanoparticles. The results of the efficiency measurement of two RPDs for two positions (sealed and unsealed) on a Sheffield head, for two inhalation configurations (constant flow and cyclic flow), and for two different particle size distributions of NaCl aerosol (one centered on 13 nm and the other on 59 nm) are presented below. The measurements indicate that when the leaks are negligible at the interface mask/head, the efficiency of RPD is greater for nanoparticles. For major leaks, the device's protection factor changes independently of the size of the particles. Furthermore, no trends with respect to the effect of the respiration type (constant-flow and cyclic-flow tests) have been shown on the device's protection factor. PMID:22752098

Brochot, C; Michielsen, N; Chazelet, S; Thomas, D

2012-07-01

299

Temperature measurements in the inner corona  

NASA Technical Reports Server (NTRS)

To increase the understanding of the acceleration of the solar wind, it is necessary to combine observations and theoretical approaches. The importance of coordinated measurements in the inner corona and interplanetary space to place constraints on solar wind models is demonstrated. Given the fact that the temperature in the inner corona is the most important parameter in solar wind modeling, observations from which reliable temperatures can be deduced are crucial for such coordinated approaches. The derivation of temperatures in the inner corona are addressed, as well as which assumptions and models are inherent in the temperatures derived using different observational techniques. Two examples of extreme ultraviolet (EUV) observations are chosen to demonstrate problems that can arise in the interpretation of measurements.

Esser, Ruth; Habbal, S. R.; Arndt, M. B.

1992-01-01

300

Turbine gas temperature measurement and control system  

NASA Technical Reports Server (NTRS)

A fluidic Turbine Inlet Gas Temperature (TIGIT) Measurement and Control System was developed for use on a Pratt and Whitney Aircraft J58 engine. Based on engine operating requirements, criteria for high temperature materials selection, system design, and system performance were established. To minimize development and operational risk, the TIGT control system was designed to interface with an existing Exhaust Gas Temperature (EGT) Trim System and thereby modulate steady-state fuel flow to maintain a desired TIGT level. Extensive component and system testing was conducted including heated (2300F) vibration tests for the fluidic sensor and gas sampling probe, temperature and vibration tests on the system electronics, burner rig testing of the TIGT measurement system, and in excess of 100 hours of system testing on a J58 engine. (Modified author abstract)

Webb, W. L.

1973-01-01

301

Laser weld penetration estimation using temperature measurements  

SciTech Connect

Penetration depth is an important factor critical to the quality of a laser weld. This paper examines the feasibility of using temperature measurements on the bottom surface of the work-piece to estimate weld penetration. A three-dimensional analytical model relating penetration depth, weld bead width and welding speed to temperature distribution at the bottom surface of the workpiece is developed. Temperatures on the bottom surface of the workpiece are measured using infrared thermocouples located behind the laser beam. Experimental results from bead-on-plate welds on low carbon steel plates of varying thickness at different levels of laser power and speeds validate the model and show that the temperature on the bottom surface is a sensitive indicator of penetration depth. The proposed model is computationally efficient and is suitable for on-line process monitoring application.

Lankalapalli, K.N.; Tu, J.F. [Purdue Univ., West Lafayette, IN (United States). School of Industrial Engineering; Leong, K.H. [Argonne National Lab., IL (United States); Gartner, M. [Ford Motor Co., Livonia, MI (United States)

1997-10-01

302

High voltage design structure for high temperature superconducting device  

DOEpatents

In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

Tekletsadik, Kasegn D. (Rexford, NY) [Rexford, NY

2008-05-20

303

Optical fiber sensor for temperature measuring  

Microsoft Academic Search

Simple fiber-optic sensor for temperature measuring, based upon the temperature-dependent bend losses in plastic clad silica optical fibers, is being proposed. The quantity of light energy transmitted along the fiber depends on the numerical aperture of the fiber, i.e. the refractive index difference between the silica core (n1) and the plastic cladding (n0). On the one hand, the refractive index

Markijan Baran

1996-01-01

304

Apparatus and method for high temperature viscosity and temperature measurements  

DOEpatents

A probe for measuring the viscosity and/or temperature of high temperature liquids, such as molten metals, glass and similar materials comprises a rod which is an acoustical waveguide through which a transducer emits an ultrasonic signal through one end of the probe, and which is reflected from (a) a notch or slit or an interface between two materials of the probe and (b) from the other end of the probe which is in contact with the hot liquid or hot melt, and is detected by the same transducer at the signal emission end. To avoid the harmful effects of introducing a thermally conductive heat sink into the melt, the probe is made of relatively thermally insulative (non-heat-conductive) refractory material. The time between signal emission and reflection, and the amplitude of reflections, are compared against calibration curves to obtain temperature and viscosity values.

Balasubramaniam, Krishnan (Mississippi State, MS); Shah, Vimal (Houston, TX); Costley, R. Daniel (Mississippi State, MS); Singh, Jagdish P. (Mississippi State, MS)

2001-01-01

305

SIC Device Development for High Temperature Sensor Applications.  

National Technical Information Service (NTIS)

Progress made in the processing and characterization of 3C-SiC for high temperature sensor applications is reviewed. Piezoresistance properties of silicon carbide and the temperature coefficient of resistivity of n-type beta-SiC are presented. In addition...

J. S. Shor D. Goldstein A. D. Kurtz R. M. Osgood

1992-01-01

306

High-power test device for package thermal assessment and validation of thermal measurement techniques  

Microsoft Academic Search

This paper describes the structure and thermal behavior of a high-power thermal test chip (up to 200 W\\/cm2) designed for power electronics package assessment, which has also been used for the validation of thermal measurement techniques. In particular, we show two application examples where the proposed device allowed the assessment of different power substrate technologies, and the validation of temperature

Xavier Jord; Xavier Perpi; Miquel Vellvehi; Francesc Madrid; Josep Altet

2010-01-01

307

[Flame temperature distribution measurement of solid propellants].  

PubMed

Many high temperature bodies such as flame, in which chemical reactions are very complex, emit their own spectra. These emission spectra usually consist of the spectral lines, spectral bands and the continuous spectra. In some cases, the spectral lines gather together. It is very difficult to find the right single spectral line when the spectral line intensity method is used. To deal with this problem, the idea that the single spectral line intensity is replaced by the total intensity of many spectral lines to measure the temperature is mentioned. And the relative intensity method is also changed to deal with this idea. The measurement of the temperature distribution based on this improved method is successful, and the measurement results are compared with the results of the thermocouple method. PMID:15762546

Zhao, Wen-hua; Zhu, Shu-guang; Li, Yan; Fang, Zhong-yan; Yang, Rong-jie; Li, Yu-ping; Zhang, Jie; Liu, Yun-fei

2004-09-01

308

Measuring salt and freezing temperature on roads  

NASA Astrophysics Data System (ADS)

Practical monitoring of the amount of salt spread on the road surface for de-icing purposes is technically difficult, especially if it has to be done in a commercially viable way. Possible solutions to this problem are discussed. As it has become customary to refer to the freezing temperature of a salted road, the physical meaning of such a temperature is scrutinised. It turns out that the meaning and the definition of freezing temperature are not clear, and that it also does not have the significance that is often associated with it. Some experimental results of salt measurements on a road are presented.

Turunen, Markus

1997-03-01

309

Temperature measurements of shock-compressed deuterium  

SciTech Connect

The authors measured the temperatures of single and double-shocked D{sub 2} and H{sub 2} up to 85 GPa (0.85 Mbar) and 5,200 K. While single shock temperatures, at pressures to 23 GPa, agree well with previous models, the double shock temperatures are as much as 40% lower than predicted. This is believed to be caused by molecular dissociation, and a new model of the hydrogen EOS at extreme conditions has been developed which correctly predicts their observations. These data and model have important implications for programs which use condensed-phase hydrogen in implosion systems.

Holmes, N.C.; Ross, M.; Nellis, W.J.

1994-11-01

310

Infrared thermography for true temperature measurement of the main board in personal computer  

NASA Astrophysics Data System (ADS)

This paper presents a way to measure the true temperature of the electronic devices without disturbing their normal operating conditions, which involved with estimating target emissivity, background temperature correctly and choosing infrared transparent material and its transmission estimation. The temperature distributions of the main board in personal computer were measured by the method presented here with infrared thermography in several different running conditions. The measurement errors and their possible remedies are also discussed.

Yang, Jing; Behnia, Masud; Morrison, Graham

2002-11-01

311

Dual neutron flux/temperature measurement sensor  

DOEpatents

Simultaneous measurement of neutron flux and temperature is provided by a single sensor which includes a phosphor mixture having two principal constituents. The first constituent is a neutron sensitive 6LiF and the second is a rare-earth activated Y203 thermophosphor. The mixture is coated on the end of a fiber optic, while the opposite end of the fiber optic is coupled to a light detector. The detected light scintillations are quantified for neutron flux determination, and the decay is measured for temperature determination. 3 figs.

Mihalczo, J.T.; Simpson, M.L.; McElhaney, S.A.

1994-10-04

312

Dual neutron flux/temperature measurement sensor  

DOEpatents

Simultaneous measurement of neutron flux and temperature is provided by a single sensor which includes a phosphor mixture having two principal constituents. The first constituent is a neutron sensitive 6LiF and the second is a rare-earth activated Y203 thermophosphor. The mixture is coated on the end of a fiber optic, while the opposite end of the fiber optic is coupled to a light detector. The detected light scintillations are quantified for neutron flux determination, and the decay is measured for temperature determination.

Mihalczo, John T. (Oak Ridge, TN); Simpson, Marc L. (Knoxville, TN); McElhaney, Stephanie A. (Oak Ridge, TN)

1994-01-01

313

Measurement of temperature using speckle shearing interferometry.  

PubMed

A laser speckle shearing interferometric technique is used for measuring the temperature profile inside a gaseous flame. The experimental results are compared with the values obtained by a thermocouple and also by speckle photography. Good agreement is seen among the temperatures measured by speckle shearing interferometry, speckle photography, and the thermocouple. Speckle shearing interferometry is easier to implement than speckle photography. This is because in speckle shearing interferometry the accurate positions of the fringes can be known without point-by-point analysis and correction for the halo effect. PMID:20885553

Shakher, C; Nirala, A K

1994-04-10

314

Physical limits and lifetime limitations of semiconductor devices at high temperatures  

Microsoft Academic Search

In many applications of electronics, a growing demand for devices being capable of operating at increased temperatures is developing. In automotive and aerospace industry, the replacement of mechanical or hydraulic systems by electronics requires harsh environmental conditions. Furthermore, the oil-well business, military, industrial, chemical, and consumer electronics show increasing interest in higher operating temperatures.In this paper, the influence of temperature

W. Wondrak

1999-01-01

315

Thermal expansion of blood vessels in low cryogenic temperatures Part I: A new experimental device  

PubMed Central

As part of the ongoing effort to study the mechanical behavior of biological material during cryopreservation processes, the current study focuses on thermal expansion of blood vessels at low cryogenic temperatures. The current paper (Part I) describes a new experimental device for thermal expansion measurements of blood vessels in typical conditions of vitrification, which are associated with rapid cooling rates. For validation purposes, the thermal strain of frozen arteries in the absence of cryoprotectants was measured, and found to be about 10% larger than that of polycrystalline water; this observation agrees with literature data. The companion paper (Part II) reports on experimental results of cryoprotectants permeated with VS55, DP6 and 7.05M DMSO at high cooling rates applicable to vitrification.

Jimenez Rios, Jorge L.; Rabin, Yoed

2006-01-01

316

Thermal expansion of blood vessels in low cryogenic temperatures Part I: A new experimental device.  

PubMed

As part of the ongoing effort to study the mechanical behavior of biological material during cryopreservation processes, the current study focuses on thermal expansion of blood vessels at low cryogenic temperatures. The current paper (Part I) describes a new experimental device for thermal expansion measurements of blood vessels in typical conditions of vitrification, which are associated with rapid cooling rates. For validation purposes, the thermal strain of frozen arteries in the absence of cryoprotectants was measured, and found to be about 10% larger than that of polycrystalline water; this observation agrees with literature data. The companion paper (Part II) reports on experimental results of cryoprotectants permeated with VS55, DP6, and 7.05 M DMSO at high cooling rates applicable to vitrification. PMID:16487503

Jimenez Rios, Jorge L; Rabin, Yoed

2006-04-01

317

Determination of the physical properties of room temperature ionic liquids using a Love wave device.  

PubMed

In this work, we have shown that a 100 MHz Love wave device can be used to determine whether room temperature ionic liquids (RTILs) are Newtonian fluids and have developed a technique that allows the determination of the density-viscosity product, ??, of a Newtonian RTIL. In addition, a test for a Newtonian response was established by relating the phase change to insertion loss change. Five concentrations of a water-miscible RTIL and seven pure RTILs were measured. The changes in phase and insertion loss were found to vary linearly with the square root of the density-viscosity product for values up to (??)(1/2) ~ 10 kg m(-2) s(-1/2). The square root of the density-viscosity product was deduced from the changes in either phase or insertion loss using glycerol as a calibration liquid. In both cases, the deduced values of ?? agree well with those measured using viscosity and density meters. Miniaturization of the device, beyond that achievable with the lower-frequency quartz crystal microbalance approach, to measure smaller volumes is possible. The ability to fabricate Love wave and other surface acoustic wave sensors using planar metallization technologies gives potential for future integration into lab-on-a-chip analytical systems for characterizing ionic liquids. PMID:21786814

Ouali, F Fouzia; Doy, Nicola; McHale, Glen; Hardacre, Christopher; Ge, Rile; Allen, Ray W K; MacInnes, Jordan M; Newton, Michael I

2011-09-01

318

High-temperature off-state characteristics of thin-SOI power devices  

Microsoft Academic Search

High-temperature off-state characteristics of thin-SOI RESURF LDMOS transistors were studied experimentally and theoretically and compared with off-state characteristics of junction-isolated bulk-Si power devices. At 200C, the off-state leakage current in the SOI devices was approximately 200 times lower than in the bulk-Si devices with a comparable breakdown voltage and on-resistance. At 300C, well beyond the operating range of the bulk

Emil Arnold; Theodore Letavic; Hemant Bhimnathwala

1996-01-01

319

Radial Profile Measurements of Plasma Parameters in the Central Cell of the Hanbit Mirror Device  

SciTech Connect

Radial profiles of plasma parameters (such as electron temperature, plasma density and floating potential) are measured in the central cell of the Hanbit mirror device. The different shaped profiles are obtained by varying the applied magnetic field in the experiment. Thus, the relation between values of plasma beta and the slope of the profile is qualitatively investigated by using measured data obtained at different magnetic fields. In addition, the characteristics of the magnetic fluctuations (less than few ten kHz) in the experiment are investigated. The experimental investigations from the measurements at different applied magnetic fields are presented.

Bak, J.G.; Lee, S.G. [Korea Basic Science Institute (Korea, Republic of)

2005-01-15

320

High-temperature superconducting thin-film-based electronic devices  

SciTech Connect

This the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project involved optimization of processing of Y123 and Tl-2212 thin films deposited on novel substrates for advanced electronic devices. The Y123 films are the basis for development of Josephson Junctions to be utilized in magnetic sensors. Microwave cavities based on the Tl-2212 films are the basis for subsequent applications as communication antennas and transmitters in satellites.

Wu, X.D; Finokoglu, A.; Hawley, M.; Jia, Q.; Mitchell, T.; Mueller, F.; Reagor, D.; Tesmer, J.

1996-09-01

321

High temperature performance measurement and analysis of GaN HEMTs  

NASA Astrophysics Data System (ADS)

Objective of this paper is to evaluate the performance of GaN HEMTs for high temperature applications. A sample AlGaN/GaN HEMT structure is investigated using empirical data to evaluate the device performance at high temperatures. Input transfer and output characteristics are the key focus along with transconductance and saturation current. Intrinsic device parameters were calculated using measured S-parameter data at various frequencies under different bias conditions and temperatures. Transconductance found at 398 K is 2.5 mS for the entire gate width. DC characteristics of the fabricated devices were examined at temperatures ranging from 295 K to 363 K. Maximum drain current measured at room temperature was 214 mA which reduced to 192 mA at 363 K. Reduction in saturation drain current is found due to decrease in saturation carrier velocity and two dimensional electron density. Structure based simulation tool ATLAS from Silvaco Int. is used for numerical simulations. The simulated device performance is in good agreement with the empirical results. Experimental results for the critical parameters suggest that the device can operate in the GHz Range for temperature up to 600 K. Further enhancement of the model device is suggested upon reviewing the measured results to improve the high-temperature performance.

Polash, B. A.; Huque, M. A.; Islam, S. K.; Huq, H.

2008-03-01

322

Temperature Effects of n-MOSFET Devices with Uniaxial Mechanical Strains  

Microsoft Academic Search

2 This study proposes a method for the investigation of the effects of uniaxial stresses, in a temperature-dependent manner, to MOSFET device characteristics, such as mobility, threshold voltage, and on-current. This simple scheme did not require complicated instruments and generated more homogeneous stresses for elucidating the effects of uniaxial me- chanical strains on MOSFET devices. Experimental and Results The NMOS

Mei-Na Tsai; T. C. Chang; Po-Tsun Liu; Osbert Cheng; C. T. Huang

2006-01-01

323

EM susceptibility studies and measurements on electro explosive devices  

NASA Astrophysics Data System (ADS)

Electroexplosive devices (EEDs) are susceptible to stray electromagnetic (EM) fields near high-power communications and radar transmitters. Experiments have been carried out to measure the exact susceptibility of EED resistive squibs in pulsed and continuous EM environments, respectively. The susceptibility test procedure consisted of individual measurements of direct current sensitivity (mA); impulse sensitivity; RF impedance measurements; and safety margin calculations. A stray energy monitor was used to evaluate the safe performance of a hybrid weapons system. It is found that the RF sensitivity of the squib was influenced by the transmission characteristics of the transmission line connected to it. RF absorption peaks were observed above the EED sensitivity threshold of 120 MHz. Methods of EMI control are discussed, including: low-pass pin filters; lossy line filters for all dc power line interconnections; and twisting and shielding of the wires.

Deb, G. K.; Mukherjee, M.

324

In Situ and Satellite Measured Temperature Comparability  

NASA Technical Reports Server (NTRS)

Following the International Geophysical Year in the late 1950's, small meteorological rockets caught the interest of scientists as a potentially inexpensive method to obtain meteorological information (density, temperature, wind) above balloon-borne radiosonde altitudes. These small rocketsondes have served many important observational roles in terms of studies conducted of atmospheric structure and processes, enabling many new ideas about the atmosphere to emerge. Although no longer manufactured a small residual inventory of meteorological rocketsondes exist for specific research projects. The value of data from meteorological rocketsondes is without question but with their disappearance data from many different satellites are filling the need, some able to resolve high-altitude temperatures quite well. However, the rocketsonde vertical profile is more localized to the launch site whereas satellites move several kilometers per second. The objective of this presentation is to compare in situ temperature data with remotely measured/retrieved temperature data. There have been a number of U.S. conducted missions utilizing the passive falling sphere data that we use to verify the comparability of retrieved temperatures from these satellites. Missions, some as early as 1991, were conducted in polar, equatorial, and mid-latitude locations. An important aspect is that a single satellite profile compared to a falling sphere profile often does not agree while high density satellite measurements when averaged over an area near the rocketsonde data area seems to be in better agreement. Radiosonde temperature data are used in the analysis when appropriate

Schmidlin, F. J.; Goldberg, R. A.; Bedrick, Mary; Rose, R. Lynn

2011-01-01

325

Ion temperature measurements in the Maryland Spheromak  

SciTech Connect

Initial spectroscopic data from MS showed evidence of ion heating as deduced from the line widths of different ion species. Detailed measurements of OIV spectral emission line profiles in space and time revealed that heating takes place at early time, before spheromak formation and is occurring within the current discharge. The measured ion temperature is several times the electron temperature and cannot be explained by classical (Spitzer) resistivity. Classically, ions are expected to have lower temperatures than the electrons and therefore, lower temperatures than observed. High ion temperatures have been observed in different RFP`s and Spheromaks but are usually associated with relaxation to the Taylor state and occur in the sustainment phase. During formation, the current delivered to start the discharge is not axisymmetric and as a consequence, X-points appear in the magnetic flux. A two dimensional analysis predicts that magnetic reconnection occurring at an X-point can give rise to high ion heating rates. A simple 0-dimensional calculation showed that within the first 20 {mu}s, a conversion of mass flow kinetic energy into ion temperature could take place due to viscosity.

Gauvreau, J.L.

1992-12-31

326

Modeling and Evaluation of Canted Coil Springs as High Temperature Seal Preloading Devices  

NASA Technical Reports Server (NTRS)

Future reusable launch vehicles will require advanced structural seals. This includes propulsion seals along edges and hinge lines in hypersonic engines, and control surface seals for movable flaps and elevons on proposed reentry vehicles. Seals must remain in sealing engagement with opposing surfaces, for multiple missions, even though the seal gap may be opening and closing due to thermal and structural loads. To meet this requirement either the seals themselves must be resilient or there must be a resilient structural element behind the seals. Case Western Reserve University is working with NASA s Glenn Research Center to develop more resilient high temperature seal components and preloading devices. Results are presented for a finite element analysis of a canted coil spring that is being considered as a high temperature seal preloading device. This type of spring is a leading candidate due to its ability to provide nearly constant force over a large deflection. The finite element analyses were verified by comparing them to experimental results of canted coil springs of three different stiffnesses, measured at Glenn Research Center. Once validated the parameterized model was combined with a scripting algorithm to assess the effects of key spring design variables (wire diameter, coils per inch, cant amplitude, eccentricity, and spring width) on spring stiffness and maximum Von Mises stress to aid in subsequent design.

Oswald, Jay J.; Mullen, Robert L.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.

2004-01-01

327

76 FR 81363 - Temperature-Indicating Devices; Thermally Processed Low-Acid Foods Packaged in Hermetically...  

Federal Register 2010, 2011, 2012, 2013

...hermetically sealed containers to allow for use of other temperature-indicating devices, in addition to mercury-in-glass thermometers, during processing. The final rule was published with one error. This document corrects that error. DATES:...

2011-12-28

328

DEPSCoR-98-High Temperature/High Speed Junction Devices and Contracts.  

National Technical Information Service (NTIS)

The goal of the project was to take an interdisciplinary approach to the improvement of high temperature devices, with an emphasis on the fabrication and optimization of metal-semiconductor connections, junction field effect transistors and other heteroju...

P. A. Dowben N. Ianno M. A. Langell B. W. Robertson

2000-01-01

329

PARduino: A Simple Device Measuring and Logging Photosynthetically Active Radiation  

NASA Astrophysics Data System (ADS)

Photosynthetically Active Radiation (PAR, 400 to 700 nm) is one of the primary controls of forest carbon and water relations. In complex terrain, PAR has high spatial-variability. Given the high cost of commercial datalogging equipment, spatially-distributed measurements of PAR have been typically modeled using geographic coordinates and terrain indices. Here, we present a design for a low cost, field-deployable device for measuring and logging PAR built around an Arduino microcontroller (we named it PARduino). PARduino provides for widely distributed sensor arrays and tests the feasibility of using hobbyist-grade electronics for collecting scientific data. PARduino components include a LiCor quantum sensor, EME Systems signal converter/amplifier, and Sparkfun's Arduino Pro Mini microcontroller. Additional components include a real time clock, a microSD flash memory card, and a custom printed circuit board (PCB). We selected the components with an eye towards ease of assembly. Everything can be connected to the PCB using through-hole soldering techniques. Since the device will be deployed in remote research plots that lack easy access to line power, battery life was also a consideration in the design. Extended deployment is possible because PARduino's software keeps it in a low-power sleep mode until ready to make a measurement. PARduino will be open-source hardware for use and improvement by others.

Barnard, H. R.; Findley, M. C.

2013-12-01

330

Methods of measurement for semiconductor materials, process control, and devices  

NASA Technical Reports Server (NTRS)

The development of methods of measurement for semiconductor materials, process control, and devices is discussed. The following subjects are also presented: (1) demonstration of the high sensitivity of the infrared response technique by the identification of gold in a germanium diode, (2) verification that transient thermal response is significantly more sensitive to the presence of voids in die attachment than steady-state thermal resistance, and (3) development of equipment for determining susceptibility of transistors to hot spot formation by the current-gain technique.

Bullis, W. M. (editor)

1971-01-01

331

Magnetic Susceptibility Measurements at Ultra-low Temperatures  

NASA Astrophysics Data System (ADS)

We report the design and operation of a device for ac magnetic susceptibility measurements that can operate down to 1 mK. The device, a modification of the standard mutual inductance bridge, is designed with detailed consideration of the thermalization and optimization of each element. First, in order to reduce local heating, the primary coil is made with superconducting wire. Second, a low-temperature transformer which is thermally anchored to the mixing chamber of a dilution refrigerator, is used to match the output of the secondary coil to a high-sensitivity bridge detector. The careful thermal anchoring of the secondary coil and the matching transformer is required to reduce the overall noise temperature and maximize sensitivity. The sample is immersed in liquid 3He to minimize the Kapitza thermal resistance. The magnetic susceptibility of several magnetic compounds, such as the well-known spin gap compound NiCl2-4SC(NH2)2 and other powdered samples, have been successfully measured to temperatures well below 10 mK.

Yin, L.; Xia, J. S.; Sullivan, N. S.; Zapf, V. S.; Paduan-Filho, A.

2010-02-01

332

Microwave electrothermal thruster chamber temperature measurements and energy exchange calculations  

NASA Astrophysics Data System (ADS)

The microwave electrothermal thruster (MET) uses microwave frequency energy to create and sustain a resonant cavity plasma to heat a propellant. It has been operated at a variety of power levels with several propellants. The performance potential of the device has not previously been ascertained because of complex physics involved in the microwave heating, the relatively low thrust of the device, and difficulty in using conventional diagnostics to study molecular plasmas. The objectives of this investigation were to measure heavy particle temperatures and to understand gas heating processes in the MET plasma chamber for representative molecular propellants, oxygen and nitrogen. These molecules have well known thermochemical and structural properties, and they are components of liquid-storable propellants. A 2.45 GHz aluminum cylindrical thruster with converging copper alloy nozzles was used. A spectroscopic system was used to collect light emitted through a window in the plasma chamber. A Schumann-Runge emission model was developed assuming anharmonically vibrating, non-rigid rotating oxygen molecules. The commercially available LIFBASE software was used to model ionized molecular nitrogen first negative system emission from nitrogen plasmas. Experimental data were compared to models using least squared difference summation schemes. Steady and repeatable plasmas were formed with oxygen, nitrogen, and ammonia for most operating conditions. Strong coupling between fluid dynamics and plasma geometry was observed for high flow rate nitrogen tests. Oxygen temperatures of 2,000 K were measured with no variation due to spatial location or pressure and a slight increase in temperature with specific absorbed power. Nitrogen temperatures of 5,500 K were measured with no variation due to location, pressure, or specific absorbed power. Thermochemical calculations show the relationship between equilibrium enthalpy addition, temperature, dissociation fraction, and specific impulse. Nitrogen was found to be an excellent choice as a propellant component while oxygen was found to be a poor choice.

Chianese, Silvio G.

333

Post-Shock Temperature Measurements of Aluminum  

SciTech Connect

Post-shock temperature is an important quantity in shock physics experiments for constraining the dynamic equations of state of materials. A high-speed, infrared, multi-wavelength pyrometer has been developed at Los Alamos National Laboratory (LANL) for measurements in the temperature range from 400 to 1200 K. With customized front end optics, permitting concurrent VISAR measurements in the same optical path, validation experiments on aluminum have been conducted at the new Shock Compression Laboratory at Harvard University. Under <1 millitorr vacuum, a post-shock temperature of 495 K {+-} 30 K was recorded from a polished free surface of aluminum 2024-T4 subject to a peak shock pressure of 34.8{+-}0.8 GPa, in excellent agreement with the equation of state and previous experiments.

Seifter, A.; Furlanetto, M. R.; Payton, J. R.; Obst, A. W. [University of California, Los Alamos National Laboratory, Physics Division, P-23, Los Alamos, NM 87545 (United States); Stewart, S. T.; Kennedy, G. B. [Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge MA 02138 (United Kingdom)

2006-07-28

334

INNOVATIVE INSTRUMENTATION AND ANALYSIS OF THE TEMPERATURE MEASUREMENT FOR HIGH TEMPERATURE GASIFICATION  

SciTech Connect

The systematic tests of the gasifier simulator were conducted in this reporting period. In the systematic test, two (2) factors were considered as the experimental parameters, including air injection rate and water injection rate. Each experimental factor had two (2) levels, respectively. A special water-feeding device was designed and installed to the gasifier simulator. Analysis of Variances (ANOVA) was applied to the results of the systematic tests. The ANOVA shows that the air injection rate did have the significant impact to the temperature measurement in the gasifier simulator. The ANOVA also shows that the water injection rate did not have the significant impact to the temperature measurements in the gasifier simulator. The ANOVA analysis also proves that the thermocouple assembly we proposed was immune to the moisture environment, the temperature measurement remained accurate in moisture environment. Within this reporting period, the vibration application for cleaning purpose was explored. Both ultrasonic and sub-sonic vibrations were considered. A feasibility test was conducted to prove that the thermocouple vibration did not have the significant impact to the temperature measurements in the gasifier simulator. This feasibility test was a 2{sup 2} factorial design. Two factors including temperature levels and motor speeds were set to two levels respectively. The sub-sonic vibration tests were applied to the thermocouple to remove the concrete cover layer (used to simulate the solid condensate in gasifiers) on the thermocouple tip. It was found that both frequency and amplitude had significant impacts on removal performance of the concrete cover layer.

Seong W. Lee

2004-04-01

335

Measuring electron temperature in the extended corona  

NASA Technical Reports Server (NTRS)

A technique for measuring electron temperature in the extended corona from the line profile of the electron scattered component of coronal H I Ly alpha produced by Thomson scattering of chromospheric Ly alpha emission is discussed. Because of the high thermal velocity of electrons at coronal temperatures (approximately 6800 km/s at T(sub e) = 1,500,000 K) the effect of nonthermal velocities and solar wind flows on the electron velocity distribution are negligible. However, the low electron mass which is responsible for the high thermal velocity also results in a very wide profile (approximately equal to 50 A). This wide profile, together with an intensity that is three orders of magnitude weaker than the resonantly scattered component of Ly alpha makes the direct measurement of T(sub e) a challenging observational problem. An evaluation of this technique based on simulated measurements is presented and the subsequent instrumental requirements necessary to make a meaningful determination of the electron temperature are discussed. Estimates of uncertainties in the measured electron temperature are related to critical instrument parameters such as grating stray light suppression.

Hassler, Donald M.; Gardner, L. D.; Kohl, John L.

1992-01-01

336

Temperature and concentration measurements in combustion  

NASA Technical Reports Server (NTRS)

A high speed two wavelength holographic interferometer is being used to simultaneously measure temperature and concentration distributions for ignition and flame spread. Lines from a cw CO2 laser were used and the holograms recorded on a movie at 500 frames per/sec, individual frames were digitized with a microdensitometer. The detection on the fringe center was a major problem.

Kashiwagi, Takashi

1987-01-01

337

Dynamic gas temperature measurement system, volume 1  

NASA Technical Reports Server (NTRS)

A gas temperature measurement system with compensated frequency response of 1 kHz and capability to operate in the exhaust of a gas turbine engine combustor was developed. A review of available technologies which could attain this objective was done. The most promising method was identified as a two wire thermocouple, with a compensation method based on the responses of the two different diameter thermocouples to the fluctuating gas temperature field. In a detailed design of the probe, transient conduction effects were identified as significant. A compensation scheme was derived to include the effects of gas convection and wire conduction. The two wire thermocouple concept was tested in a laboratory burner exhaust to temperatures of about 3000 F and in a gas turbine engine to combustor exhaust temperatures of about 2400 F. Uncompensated and compensated waveforms and compensation spectra are presented.

Elmore, D. L.; Robinson, W. W.; Watkins, W. B.

1983-01-01

338

Transient Liquid Phase Die Attach for High-Temperature Silicon Carbide Power Devices  

Microsoft Academic Search

Recently, silicon carbide power devices have been receiving attention for applications above 300 C. For high-temperature applications, the die attached for these devices has to withstand the maximum operating temperature. In this paper, a transient liquid phase (TLP) die attach technique was demonstrated for two binary alloy systems, Ag-In and Au-In, on Si3N4 substrates. A nearly void-free joint was developed

Habib A. Mustain; William D. Brown; Simon S. Ang

2010-01-01

339

High-Temperature Operation of SiC Power Devices by Low-Temperature Sintered Silver Die-Attachment  

Microsoft Academic Search

In this paper, we present the realization of high-temperature operation of SiC power semiconductor devices by low-temperature sintering of nanoscale silver paste as a novel die-attachment solution. The silver paste was prepared by mixing nanoscale silver particles with carefully selected organic components which can burn out within the low-temperature firing range. SiC Schottky diodes were placed onto stencil-printed layers of

John Guofeng Bai; Jian Yin; Zhiye Zhang; Guo-Quan Lu; Jacobus Daniel van Wyk

2007-01-01

340

Measurement of Thin Film Integrated Passive Devices on SiC through 500 C  

NASA Technical Reports Server (NTRS)

Wireless communication in jet engines and high temperature industrial applications requires FD integrated circuits (RFICs) on wide bandgap semiconductors such as Silicon Carbide (SiC). In this paper, thin-film NiCr resistors, MIM capacitors, and spiral inductors are fabricated on a high purity semi-insulating 4H-SiC substrate. The devices are experimentally characterized through 50 GHz at temperatures of up to 500 C and the equivalent circuits are deembedded from the measured data. It is shown that the NiCr resistors are stable within 10% to 300 C while the capacitors have a value stable within 10% through 500 C.

Schwartz, Zachary D.; Ponchak, George E.; Alterovitz, Samuel A.; Downey, Alan N.; Chevalier, Christine T.

2004-01-01

341

A Fast Microfluidic Temperature Control Device for Studying Microtubule Dynamics in Fission Yeast  

PubMed Central

Recent development in soft lithography and microfluidics enables biologists to create tools to control the cellular microenvironment. One such control is the ability to quickly change the temperature of the cells. Genetic model organism such as fission yeast has been useful for studies of the cell cytoskeleton. In particular, the dynamic microtubule cytoskeleton responds to changes in temperature. In addition, there are temperature-sensitive mutations of cytoskeletal proteins. We describe here the fabrication and use of a microfluidic device to quickly and reversibly change cellular temperature between 2C and 50C. We demonstrate the use of this device while imaging at high-resolution microtubule dynamics in fission yeast.

Velve-Casquillas, Guilhem; Costa, Judite; Carlier-Grynkorn, Frederique; Mayeux, Adeline; Tran, Phong T.

2010-01-01

342

Measuring Rocket Engine Temperatures with Hydrogen Raman Spectroscopy  

NASA Technical Reports Server (NTRS)

Optically accessible, high pressure, hot fire test articles are available at NASA Marshall for use in development of advanced rocket engine propellant injectors. Single laser-pulse ultraviolet (UV) Raman spectroscopy has been used in the past in these devices for analysis of high pressure H2- and CH4-fueled combustion, but relies on an independent pressure measurement in order to provide temperature information. A variation of UV Raman (High Resolution Hydrogen Raman Spectroscopy) is under development and will allow temperature measurement without the need for an independent pressure measurement, useful for flows where local pressure may not be accurately known. The technique involves the use of a spectrometer with good spectral resolution, requiring a small entrance slit for the spectrometer. The H2 Raman spectrum, when created by a narrow linewidth laser source and obtained from a good spectral resolution spectrograph, has a spectral shape related to temperature. By best-fit matching an experimental spectrum to theoretical spectra at various temperatures, a temperature measurement is obtained. The spectral model accounts for collisional narrowing, collisional broadening, Doppler broadening, and collisional line shifting of each Raman line making up the H2 Stokes vibrational Q-branch spectrum. At pressures from atmospheric up to those associated with advanced preburner components (5500 psia), collisional broadening though present does not cause significant overlap of the Raman lines, allowing high resolution H2 Raman to be used for temperature measurements in plumes and in high pressure test articles. Experimental demonstrations of the technique are performed for rich H2-air flames at atmospheric pressure and for high pressure, 300 K H2-He mixtures. Spectrometer imaging quality is identified as being critical for successful implementation of technique.

Wehrmeyer, Joseph A.; Osborne, Robin J.; Trinh, Huu P.; Turner, James (Technical Monitor)

2001-01-01

343

Development of a continuous aerosol mass concentration measurement device.  

PubMed

A dynamic aerosol mass concentration measurement device has been developed for personal sampling. Its principle consists in sampling the aerosol on a filter and monitoring the change of pressure drop over time (Delta P). Ensuring that the linearity of the Delta P = f(mass of particles per unit area of filter) relationship has been well established, the change of concentration can be deduced. The response of the system was validated in the laboratory with a 3.5 microm alumina aerosol (mass median diameter) generated inside a 1-m(3) ventilated enclosure. As the theory predicted that the mass sensitivity of the system would vary inversely with the square of the particle diameter, only sufficiently fine aerosols were able to be measured. The system was tested in the field in a mechanical workshop in the vicinity of an arc-welding station. The aerosol produced by welding is indeed particularly well-adapted due to the sub-micronic size of the particles. The device developed, despite this limitation, has numerous advantages over other techniques: robustness, compactness, reliability of calibration, and ease of use. PMID:12851007

Bmer, D; Thomas, D; Contal, P; Subra, I

2003-08-01

344

STP Temperature Measurement Lennard-Jones Program  

NSDL National Science Digital Library

The STP TemperatureMeasurementLJ program simulates the exchange energy between a demon and a system of particles interacting via the Lennard-Jones potential. The program shows the kinetic temperature of the system as a function of time, and the energy distribution of the demon. The purpose of this simulation is to understand why the demon acts as an ideal thermometer The default system is a one-dimensional ideal gas of N=64 particles in a box with linear dimension 30 and initial kinetic energy per particle of 1.0. Additional states and parameters can be specified using the Display|Switch GUI menu item. STP TemperatureMeasurementLJ is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double-clicking the stp_TemperatureMeasurementLJ.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2009-03-03

345

High temperature measurement of water vapor absorption  

NASA Technical Reports Server (NTRS)

An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

1985-01-01

346

Self-absorption of H? line in pellet ablation clouds in devices with magnetic confinement of high-temperature plasma  

NASA Astrophysics Data System (ADS)

We have determined the optical absorption depth for H? line in clouds of secondary plasma near pellets ablating in high-temperature plasma of devices with magnetic confinement. It is established that, for all values of the electron concentration (1016-3 1017 cm-3) and electron temperature (2-5 eV) measured in typical impurity pellet clouds, the absorption is negligibly small. At the same time, it can be significant in clouds of higher density (1017-5 1017 cm-3) with a temperature of 1-2 eV, which are typical of cryogenic fuel pellets.

Sharov, I. A.; Sergeev, V. Yu.; Miroshnikov, I. V.

2014-04-01

347

Description of a Portable Wireless Device for High-Frequency Body Temperature Acquisition and Analysis  

PubMed Central

We describe a device for dual channel body temperature monitoring. The device can operate as a real time monitor or as a data logger, and has Bluetooth capabilities to enable for wireless data download to the computer used for data analysis. The proposed device is capable of sampling temperature at a rate of 1 sample per minute with a resolution of 0.01 C . The internal memory allows for stand-alone data logging of up to 10 days. The device has a battery life of 50 hours in continuous real-time mode. In addition to describing the proposed device in detail, we report the results of a statistical analysis conducted to assess its accuracy and reproducibility.

Cuesta-Frau, David; Varela, Manuel; Aboy, Mateo; Miro-Martinez, Pau

2009-01-01

348

Modeling a measurement-device-independent quantum key distribution system.  

PubMed

We present a detailed description of a widely applicable mathematical model for quantum key distribution (QKD) systems implementing the measurement-device-independent (MDI) protocol. The model is tested by comparing its predictions with data taken using a proof-of-principle, time-bin qubit-based QKD system in a secure laboratory environment (i.e. in a setting in which eavesdropping can be excluded). The good agreement between the predictions and the experimental data allows the model to be used to optimize mean photon numbers per attenuated laser pulse, which are used to encode quantum bits. This in turn allows optimization of secret key rates of existing MDI-QKD systems, identification of rate-limiting components, and projection of future performance. In addition, we also performed measurements over deployed fiber, showing that our system's performance is not affected by environment-induced perturbations. PMID:24921468

Chan, P; Slater, J A; Lucio-Martinez, I; Rubenok, A; Tittel, W

2014-06-01

349

Cloud and surface classification using SCIAMACHY polarization measurement devices  

NASA Astrophysics Data System (ADS)

A simple scheme has been developed to discriminate surface, sun glint and cloud properties in satellite based spectrometer data utilizing visible and near infrared information. It has been designed for the use with data measured by SCIAMACHY's (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) Polarization Measurement Devices but the applicability is not strictly limited to this instrument. The scheme is governed by a set of constraints and thresholds developed by using satellite imagery and meteorological data. Classification targets are ice, water and generic clouds, sun glint and surface parameters, such as water, snow/ice, desert and vegetation. The validation is done using MERIS (MEdium Resolution Imaging Spectrometer) and meteorological data from METAR (MTorologique Aviation Rgulire - a network for the provision of meteorological data for aviation). Qualitative and quantitative validation using MERIS satellite imagery shows good agreement. The comparison with METAR data exhibits very good agreement.

Lotz, W. A.; Vountas, M.; Dinter, T.; Burrows, J. P.

2008-05-01

350

Investigation of high-temperature superconducting flywheel energy storage devices  

NASA Astrophysics Data System (ADS)

The paper studies a possibility of the technology of a high-temperature superconducting flywheel energy storage system and extracts its technical subjects. As a result of investigating the present status of technology and development of the flywheel for the electric energy storage system, it is found that it is a promising technology which has basically a wide applicability to multipurposes. A combination of the technology only with the existing element technology is fully feasible, and the system shows excellent performance in energy storage for medium-scale capacity for a relatively short period. However, there have been seen few application examples. For application to power systems and industrial systems, it is necessary to reduce operational loss of the system and to realize flywheels which can store much larger capacities of energy. It is proposed that a combination of high-temperature superconducting bulk and permanent magnet is used for magnetic supporting of the flywheel. Technical problems are also extracted of the high temperature superconducting flywheel system as an energy storage system for load leveling.

1994-03-01

351

Simple uniaxial pressure device for ac-susceptibility measurements suitable for closed cycle refrigerator system  

NASA Astrophysics Data System (ADS)

A simple design of the uniaxial pressure device for the measurement of ac-susceptibility at low temperatures using closed cycle refrigerator system is presented for the first time. This device consists of disc micrometer, spring holder attachment, uniaxial pressure cell, and the ac-susceptibility coil wound on stycast bobbin. It can work under pressure till 0.5 GPa and at the temperature range of 30-300 K. The performance of the system at ambient pressure is tested and calibrated with standard paramagnetic salts [Gd2O3, Er2O3, and Fe(NH4SO4)26H2O], Fe3O4, Gd metal, Dy metal, superconductor (YBa2Cu3O7), manganite (La1.85Ba0.15MnO3), and spin glass material (Pr0.8Sr0.2MnO3). The performance of the uniaxial pressure device is demonstrated by investigating the uniaxial pressure dependence of La1.85Ba0.15MnO3 single crystal with P?c axis. The Curie temperature (Tc) decreases as a function of pressure with P?c axis (dTc/dP?c axis=-11.65 K/GPa) up to 46 MPa. The design is simple, is user friendly, and does not require pressure calibration. Measurement can even be made on thin and small size oriented crystals. The failure of the coil is remote under uniaxial pressure. The present setup can be used as a multipurpose uniaxial pressure device for the measurement of Hall effect and thermoelectric power with a small modification in the pressure cell.

Arumugam, S.; Manivannan, N.; Murugeswari, A.

2007-06-01

352

Infrared thermography for true temperature measurement of the main board in personal computer  

Microsoft Academic Search

This paper presents a way to measure the true temperature of the electronic devices without disturbing their normal operating\\u000a conditions, which involved with estimating target emissivity, background temperature correctly and choosing infrared transparent\\u000a material and its transmission estimation. The temperature distributions of the main board in personal computer were measured\\u000a by the method presented here with infrared thermography in several

Jing Yang; Masud Behnia; Graham Morrison

2002-01-01

353

Measurement of electrostatic potential fluctuation using heavy ion beam probe in large helical device  

SciTech Connect

Heavy ion beam probe (HIBP) for large helical device (LHD) has been improved to measure the potential fluctuation in high-temperature plasmas. The spatial resolution is improved to about 10 mm by controlling the focus of a probe beam. The HIBP is applied to measure the potential fluctuation in plasmas where the rotational transform is controlled by electron cyclotron current drive. The fluctuations whose frequencies change with the time constant of a few hundreds of milliseconds and that with a constant frequency are observed. The characteristics of the latter fluctuation are similar to those of the geodesic acoustic mode oscillation. The spatial profiles of the fluctuations are also obtained.

Ido, Takeshi; Shimizu, Akihiro; Nishiura, Masaki; Nakano, Haruhisa; Ohshima, Shinsuke; Kato, Shinji; Hamada, Yasuji; Yoshimura, Yasuo; Kubo, Shin; Shimozuma, Takashi; Igami, Hiroe; Takahashi, Hiromi; Toi, Kazuo; Watanabe, Fumitake [National Institute for Fusion Science, Gifu 509-5292 (Japan)

2008-10-15

354

Wireless Temperature Measurement and Control System Based on MSP430F149  

Microsoft Academic Search

This design takes the 16-bit ultra-low power MSP430F149 micro controller produced by TI Company as the control core. Using a high-precision single-bus device DS18B20 as the temperature sensor, the keyboard as the temperature input setting, and the temperature value displayed by the 1602 LCD, temperature measurement and controlling are realized within the closed environment. And the nRF401 wireless transmission module

Wei Jia; Peng Xie; Guo-qin Feng

2010-01-01

355

Portable measurement, analysis device can calculate GLE/SRE  

SciTech Connect

In today`s natural gas market environment it is particularly important for buyers to receive exact flow measurement data. However, it is difficult to receive accurate measurement data because of pulsation problems within the pipe line system. Pulsation, which can be caused by compressors, flow control valves, regulators and some pipe configurations, can alter gas flow measurement. To receive exact measurements, many gas buyers require a pulsation clause, guaranteeing that suppliers maintain a pulsation level in their lines within specifications. To this end, customers often insist that suppliers provide a square root error (SRE) measurement that indicates the amount of pulsation a pipe line experiences and that it is within specified limits. Measuring GLE and SRE errors can be a time consuming, troublesome task. The PGI GLE/SRE tester is a portable measurement and analysis device designed to solve this problem. It can quickly and accurately calculate GLE and SRE and other errors, and stores real-time flow data on disk. This data portability enables engineers to study and analyze the data at a later time. Developed for Precision General by Integrated Scientific Resources, the GLE/SRE tester accurately measures those primary-element and secondary-element errors identified by The Pipeline and Compressor Research Council (PCRC) of the Southern Gas Association (SGA), and the Southwest Research Institute (SWI). The unit includes a Twinhead 486DX/33 laptop computer, a Keithley MetraByte DAS-1200 and DAStation expansion chassis for notebook computers, two Rosemount 3051C differential pressure transmitters, A Validyne P305D differential pressure transducer, and PipePeer software. The laptop compatible has a 33 MHz clock, 200 MBytes of hard drive storage and an LCD display.

Hary, D. [Integrated Scientific Resources, Santa Monica, CA (United States); Miller, M.R. [Precision General, Inc., Houston, TX (United States)

1995-05-01

356

Multilayer compressive seal for sealing in high temperature devices  

DOEpatents

A mica based compressive seal has been developed exhibiting superior thermal cycle stability when compared to other compressive seals known in the art. The seal is composed of compliant glass or metal interlayers and a sealing (gasket) member layer composed of mica that is infiltrated with a glass forming material, which effectively reduces leaks within the seal. The compressive seal shows approximately a 100-fold reduction in leak rates compared with previously developed hybrid seals after from 10 to about 40 thermal cycles under a compressive stress of from 50 psi to 100 psi at temperatures in the range from 600.degree. C. to about 850.degree. C.

Chou, Yeong-Shyung (Richland, WA); Stevenson, Jeffry W. (Richland, WA)

2007-08-21

357

Improved Refractometer for Measuring Temperatures of Drops  

NASA Technical Reports Server (NTRS)

The Dual Rainbow refractometer is an enhanced version of the Rainbow refractometer, which is added to, and extends the capabilities of, a phase Doppler particle analyzer (PDPA). A PDPA utilizes pairs of laser beams to measure individual components of velocity and sizes of drops in a spray. The Rainbow-refractometer addition measures the temperatures of individual drops. The designs of prior versions of the Rainbow refractometer have required substantial modifications of PDPA transmitting optics, plus dedicated lasers as sources of illumination separate from, and in addition to, those needed for PDPA measurements. The enhancement embodied in the Dual Rainbow refractometer eliminates the need for a dedicated laser and confers other advantages as described below. A dedicated laser is no longer needed because the Dual Rainbow refractometer utilizes one of the pairs of laser beams already present in a PDPA. Hence, the design of the Dual Rainbow refractometer simplifies the task of upgrading PDPA hardware to enable measurement of temperature. Furthermore, in a PDPA/Dual Rainbow refractometer system, a single argon-ion laser with three main wavelengths can be used to measure the temperatures, sizes, and all three components of velocity (in contradistinction to only two components of velocity in a prior PDPA/Rainbow refractometer system). In order to enable the Dual Rainbow refractometer to utilize a pair of PDPA laser beams, it was necessary to (1) find a location for the refractometer receiver, such that the combined rainbow patterns of two laser beams amount to a pattern identical to that of a single beam, (2) adjust the polarization of the two beams to obtain the strongest rainbow pattern, and (3) find a location for the PDPA receiver to obtain a linear relationship between the measured phase shift and drop size.

Naqwi, Amir A.

2004-01-01

358

Temperature-insensitive miniaturized fiber inline Fabry-Perot interferometer for highly sensitive refractive index measurement.  

PubMed

We report a miniaturized fiber inline Fabry-Perot interferometer (FPI), with an open micro-notch cavity fabricated by one-step fs laser micromachining, for highly sensitive refractive index measurement. The device was tested for measurement of the refractive indices of various liquids including isopropanol, acetone and methanol at room temperature, as well as the temperature-dependent refractive index of deionized water from 3 to 90 degrees C. The sensitivity for measurement of refractive index change of water was 1163 nm/RIU at the wavelength of 1550 nm. The temperature cross-sensitivity of the device was about 1.1x10(-6) RIU/degrees C. The small size, all-fiber structure, small temperature dependence, linear response and high sensitivity, make the device attractive for chemical and biological sensing. PMID:18542685

Wei, Tao; Han, Yukun; Li, Yanjun; Tsai, Hai-Lung; Xiao, Hai

2008-04-14

359

Thermoreflectance temperature measurement with millimeter wave.  

PubMed

GigaHertz (GHz) thermoreflectance technique is developed to measure the transient temperature of metal and semiconductor materials located behind an opaque surface. The principle is based on the synchronous detection, using a commercial THz pyrometer, of a modulated millimeter wave (at 110 GHz) reflected by the sample hidden behind a shield layer. Measurements were performed on aluminum, copper, and silicon bulks hidden by a 5 cm thick Teflon plate. We report the first measurement of the thermoreflectance coefficient which exhibits a value 100 times higher at 2.8 mm radiation than those measured at visible wavelengths for both metallic and semiconductor materials. This giant thermoreflectance coefficient ?, close to 10(-3) K(-1) versus 10(-5) K(-1) for the visible domain, is very promising for future thermoreflectance applications. PMID:24985839

Pradere, C; Caumes, J-P; BenKhemis, S; Pernot, G; Palomo, E; Dilhaire, S; Batsale, J-C

2014-06-01

360

Practical aspects of measurement-device-independent quantum key distribution  

NASA Astrophysics Data System (ADS)

A novel protocol, measurement-device-independent quantum key distribution (MDI-QKD), removes all attacks from the detection system, the most vulnerable part in QKD implementations. In this paper, we present an analysis for practical aspects of MDI-QKD. To evaluate its performance, we study various error sources by developing a general system model. We find that MDI-QKD is highly practical and thus can be easily implemented with standard optical devices. Moreover, we present a simple analytical method with only two (general) decoy states for the finite decoy-state analysis. This method can be used directly by experimentalists to demonstrate MDI-QKD. By combining the system model with the finite decoy-state method, we present a general framework for the optimal choice of the intensities of the signal and decoy states. Furthermore, we consider a common situation, namely asymmetric MDI-QKD, in which the two quantum channels have different transmittances. We investigate its properties and discuss how to optimize its performance. Our work is of interest not only to experiments demonstrating MDI-QKD but also to other non-QKD experiments involving quantum interference.

Xu, Feihu; Curty, Marcos; Qi, Bing; Lo, Hoi-Kwong

2013-11-01

361

A diffusive sampling device for measurement of ammonia in air  

NASA Astrophysics Data System (ADS)

A diffusive sampling device, the DSD-NH3, has been developed for measurement of ammonia in air. The DSD-NH3 comprises silica gel impregnated with phosphoric acid as the absorbent, a porous sintered polyethylene tube that acts as a diffusive membrane, and a small polypropylene syringe that is used for the elution of analytes from the absorbent. Silica gel impregnated with phosphoric acid is used as absorbent for the DSD-NH3; basic gases in ambient air, including ammonia, are trapped in the DSD-NH3 device by their reaction with phosphoric acid in the sampler to form their corresponding phosphoric acid salts. After collection, the DSD-NH3 samplers are eluted by water. Cations in the eluate, including ammonium ions, are analyzed by ion chromatography. A side-by-side comparison was made with active samplers, demonstrating good correlation (r2 = 0.996). The sampling rate (94.5 ml min-1) was determined from comparison with an active sampling method and sampling rates. The sampling rate is also calculated from the respective molecular weights according to a rule based on Graham's law. The theoretical sampling rate with the DSD-NH3 is 95.4 ml min-1 and agrees with the experimental value (94.5 ml min-1). Little influence of wind velocity on the sampler was observed. The relative standard deviations for ammonia concentrations were 4.7% with face velocity ranging 0-5.0 m/s.

Yamada, Tomomi; Uchiyama, Shigehisa; Inaba, Yohei; Kunugita, Naoki; Nakagome, Hideki; Seto, Hiroshi

2012-07-01

362

Method and device for noninvasive blood glucose measurement  

NASA Astrophysics Data System (ADS)

The method and device for non-invasive measurement of blood glucose concentration based on the diffuse reflectance from the transcutaneous layers is proposed. Original normalizing ratio algorithm permitting to separate glucose absorption from absorption of other blood components is suggested. It was shown that the influence of water and some other components such as hemoglobin, albumin, globulin's and cholesterol concentration variations to the estimation of the glucose concentration can be compensated using spectral analysis of the reflection on several specially selected wavelengths and proposed algorithm. Device with optical geometry minimizing the effects of changes in the scattering background of biological tissues was developed. NIR spectral range 800 - 1800 nm was used because of its good transparency for biological tissue and presence of glucose absorption band. We used two kinds of light sources, namely LED array and Xe flash lamp. Tissue phantoms (different glucose concentration (0 - 1000 mg/dl) solutions with polystyrene beads or with milk) were used as samples. Scattering and absorption contribution to the dependence of diffuse reflection on glucose concentration was experimentally verified.

Amerov, Airat K.; Jeon, Kye Jin; Kim, Yoen-Joo; Yoon, Gilwon

1999-05-01

363

Experimental measurement and mathematical calculation evaporator temperatures of closed loop thermosyphon  

NASA Astrophysics Data System (ADS)

The closed loop thermoshypon is device operate with working fluid phase change principle. It is a simple and reliable device providing heat transfer. This device utilizes the thermodynamic pressure difference and gravitation to circulate working fluid and has extremely high effective thermal conductivity. Usually is used to cooling of electronic components. The paper describes a design and construction of this device. As a working fluid was used fluorinert FC-72. Next the paper deal with dependences measurement of evaporator temperatures on waste heat of the electronic component and their verification by means of a mathematic calculation based on physical phenomena of boiling, condensation and heat transfer.

Nemec, Patrik; Malcho, Milan; Janda?ka, Jozef

2013-10-01

364

Memory-assisted measurement-device-independent quantum key distribution  

NASA Astrophysics Data System (ADS)

A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user?s end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations.

Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Ltkenhaus, Norbert

2014-04-01

365

Measurement procedures for electromagnetic compatibility assessment of electroexplosive devices  

NASA Astrophysics Data System (ADS)

A rigorous approach for characterizing electroexplosive-device (EED) firing levels is developed in the context of statistical linear models. The authors combine statistical theory and methodology with thermodynamic modeling to determine the probability that an EED of a particular type fires when excited by a pulse of a given width and amplitude. Methods for assessing model validity and for obtaining probability plots, called firing likelihood plots, are included. The results provide information that is crucial for evaluating the effects of currents induced by impulsive electromagnetic fields of short duration relative to the thermal time constant of an EED. Methods of measuring the thermal time constant of an EED and the energy needed to fire an EED with a single current impulse are given.

Adams, John W.; Friday, Dennis S.

1988-11-01

366

Measuring material relaxation and creep recovery in a microfluidic device.  

PubMed

We present a novel method of testing creep recovery in a microfluidic device. This method allows for the measurement of relaxation time of fluids at low strain. After applying a steady pressure-driven flow along a microchannel, the pressure is released and the fluid is allowed to relax and come to rest. Local strains are observed via the time-dependent velocity profiles and are fit to a general viscoelastic model to obtain the fluids' relaxation times. The use of polymeric solutions of various molecular weights allows for the observation of time scales for strains ranging from 0.01 to 10. Results are consistent with data obtained in a macroscopic rheometer and with a viscoelastic constitutive model. PMID:23525332

Koser, Alison E; Pan, Lichao; Keim, Nathan C; Arratia, Paulo E

2013-05-21

367

Continuous-variable measurement-device-independent quantum key distribution  

NASA Astrophysics Data System (ADS)

We propose a continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, in which detection is conducted by an untrusted third party. Our protocol can defend all detector side channels, which seriously threaten the security of a practical CV QKD system. Its security analysis against arbitrary collective attacks is derived based on the fact that the entanglement-based scheme of CV-MDI QKD is equivalent to the conventional CV QKD with coherent states and heterodyne detection. We find that the maximal total transmission distance is achieved by setting the untrusted third party close to one of the legitimate users. Furthermore, an alternate detection scheme, a special application of CV-MDI QKD, is proposed to enhance the security of the standard CV QKD system.

Li, Zhengyu; Zhang, Yi-Chen; Xu, Feihu; Peng, Xiang; Guo, Hong

2014-05-01

368

Broad-band Cryogenic Microwave Filtering Scheme for Operating Devices at Sub 0.1 Kelvin Temperatures  

Microsoft Academic Search

We developed compact low-pass filters for transport experiments with single-electron devices at temperatures below 0.1 Kelvin. The filter assembly consists of a coil made of a long thin copper wire placed in a chamber filled with stainless still powder. The transmission of the filter at frequencies between 40 MHz and 20 GHz was measured using a Vector Analyzer (Anritsu Lightning)

Kristen Herrmann; Andrei Kogan

2007-01-01

369

High sensitivity optical fiber temperature sensor based on the temperature cross-sensitivity feature of RI-sensitive device  

NASA Astrophysics Data System (ADS)

Considerable part of optical fiber refractive index (RI) sensors suffer from the drawback of cross-sensitivity to temperature because of the thermo-optic effect of materials. In this paper, we propose a straightforward method to utilize the temperature cross-sensitivity feature of an optical fiber RI-sensitive device and thus got a high sensitivity temperature sensor. The sensor consists of a single mode fiber-multimode fiber core(MMFC)-single mode fiber structural refractometer encapsulated into a deionized water-filled cylindrical aluminum alloy shell. Benefiting from the larger thermo-optic coefficient difference between water and MMFC compared with the general cladding and core, the wavelength of transmitted spectrum presents enhanced shift when the ambient temperature change and thus get a higher temperature sensitivity. Experimental results show that the enhanced temperature sensitivity is about 358 pm/C, which is almost 30 times that of the inherent temperature sensitivity.

Sun, Hao; Hu, Manli; Rong, Qiangzhou; Du, Yanying; Yang, Hangzhou; Qiao, Xueguang

2014-07-01

370

Surface acoustic wave devices for wireless strain measurement  

Microsoft Academic Search

Strain monitoring is a nondestructive inspection method that can reveal the redistribution of internal forces, or the presence of anomalous loadings, in structures. Surface acoustic wave (SAW) devices are small, robust, inexpensive solid-state components in which a wave propagates along the surface of a piezoelectric material, and such devices are used in large numbers commercially as delay devices and as

T.-L. Chin; Peng Zheng; Irving J. Oppenheim; David W. Greve

2010-01-01

371

Characterization of devices, circuits, and high-temperature superconductor transmission lines by electro-optic testing  

NASA Technical Reports Server (NTRS)

The development of a capability for testing transmission lines, devices, and circuits using the optically-based technique of electro-optics sampling was the goal of this project. Electro-optic network analysis of a high-speed device was demonstrated. The project involved research on all of the facets necessary in order to realize this result, including the discovery of the optimum electronic pulse source, development of an adequate test fixture, improvement of the electro-optic probe tip, and identification of a device which responded at high frequency but did not oscillate in the test fixture. In addition, during the process of investigating patterned high-critical-temperature superconductors, several non-contacting techniques for the determination of the transport properties of high T(sub c) films were developed and implemented. These are a transient, optical pump-probe, time-resolved reflectivity experiment, an impulsive-stimulated Raman scattering experiment, and a terahertz-beam coherent-spectroscopy experiment. The latter technique has enabled us to measure both the complex refractive index of an MgO substrate used for high-T(sub c) films and the complex conductivity of a YBa2Cu3O(7-x) sample. This information was acquired across an extremely wide frequency range: from the microwave to the submillimeter-wave regime. The experiments on the YBCO were conducted without patterning of, or contact to, the thin film. Thus, the need for the more difficult transmission-line experiments was eliminated. Progress in all of these areas was made and is documented in a number of papers. These papers may be found in the section listing the abstracts of the publications that were issued during the course of the research.

Whitaker, John F.

1991-01-01

372

Ion Flow and Temperature Measurements in Turbulent CSDX Plasmas  

NASA Astrophysics Data System (ADS)

Experiments in the Controlled Shear Decorrelation Experiment device have shown that an azimuthally symmetric, radially sheared plasma fluid flow arises spontaneously when the primarily axial magnetic field lines terminate on insulating boundaries. Theory suggests that the shear flow is sustained by the Reynolds stress generated by collisional drift turbulence. The measurements were based on Time Delay Estimation, which cannot distinguish between ion fluid velocities and wave phase velocities, and Mach probes, which are perturbative. We present measurements of the radial profiles of ion flows and temperatures as measured with laser induced florescence in argon. The measurements were obtained with a portable, high power (> 350 W), tunable diode laser-based system operating at 668.614 nm. Mode hop free tuning of the laser over 30 GHz permitted the measurement of the entire ion velocity distribution function in a single laser frequency scan. The absolute wavelength was simultaneously recorded for each laser frequency. We will report radial profiles of ion temperature and bulk flow for both turbulent and quiescent flow regimes.

McCarren, Dustin; Scime, Earl; Thakur, Saikat; Lee, Ty; Tynan, George

2011-11-01

373

Effects of chamber pressure variation on the grid temperature in an inertial electrostatic confinement device  

NASA Astrophysics Data System (ADS)

Inertial electrostatic confinement fusion devices are compact sources of neutrons, protons, electrons, and x rays. Such sources have many applications. Improving the efficiency of the device also increases the applications of this device. Hence a thorough understanding of the operation of this device is needed. In this paper, we study the effect of chamber pressure on the temperature of the cathode. Experimentally, the grid temperature decreases as the chamber pressure increases; numerical simulations suggest that this is caused by the reduction of the hot ion current to the cathode as the pressure increases for constant power supply current. Such an understanding further supports the conclusion that the asymmetric heating of the cathode can be decreased by homogenizing the ion flow around the cathode.

Murali, S. Krupakar; Emmert, G. A.; Santarius, J. F.; Kulcinski, G. L.

2010-10-01

374

Effects of chamber pressure variation on the grid temperature in an inertial electrostatic confinement device  

SciTech Connect

Inertial electrostatic confinement fusion devices are compact sources of neutrons, protons, electrons, and x rays. Such sources have many applications. Improving the efficiency of the device also increases the applications of this device. Hence a thorough understanding of the operation of this device is needed. In this paper, we study the effect of chamber pressure on the temperature of the cathode. Experimentally, the grid temperature decreases as the chamber pressure increases; numerical simulations suggest that this is caused by the reduction of the hot ion current to the cathode as the pressure increases for constant power supply current. Such an understanding further supports the conclusion that the asymmetric heating of the cathode can be decreased by homogenizing the ion flow around the cathode.

Murali, S. Krupakar [Lawrenceville Plasma Physics, 128 Lincoln Blvd., Middlesex, New Jersey 08846 (United States); Emmert, G. A.; Santarius, J. F.; Kulcinski, G. L. [Fusion Technology Institute, University of Wisconsin, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States)

2010-10-15

375

Development of nickel aluminide microchannel array devices for high-temperature applications  

Microsoft Academic Search

The miniaturization of Microtechnology-based Energy, Chemical and Biological Systems (MECS) is made possible by the use of high aspect ratio microchannel arrays to increase the surface-area-to-volume ratio of the flow conduits within the devices, resulting in an improvement in the heat and mass transfer performance of the devices. However, advantages of the MECS concept cannot be applied to high-temperature applications

Kannachai Kanlayasiri

2003-01-01

376

Spin-transfer switching of orthogonal spin-valve devices at cryogenic temperatures  

NASA Astrophysics Data System (ADS)

We present the quasi-static and dynamic switching characteristics of orthogonal spin-transfer devices incorporating an out-of-plane magnetized polarizing layer and an in-plane magnetized spin valve device at cryogenic temperatures. Switching at 12 K between parallel and anti-parallel spin-valve states is investigated for slowly varied current as well as for current pulses with durations as short as 200 ps. We demonstrate 100% switching probability with current pulses 0.6 ns in duration. We also present a switching probability diagram that summarizes device switching operation under a variety of pulse durations, amplitudes, and polarities.

Ye, L.; Gopman, D. B.; Rehm, L.; Backes, D.; Wolf, G.; Ohki, T.; Kirichenko, A. F.; Vernik, I. V.; Mukhanov, O. A.; Kent, A. D.

2014-05-01

377

Quantum efficiency measurements in the swept charge device CCD236  

NASA Astrophysics Data System (ADS)

The e2v technologies plc. CCD236 is a Swept Charge Device (SCD) designed as a large area (20 mm 20 mm) soft X-ray detector for spectroscopy in the range 0.8 keV to 10 keV. It benefits from improvements in design over the previous generation, the e2v CCD54, such as: a 4 times increased detector area, a reduction in split X-ray events due to the 100 ?m 100 ?m `pixel' size, and improvements to radiation hardness. The CCD236 will be used in India's Chandrayaan-2 Large Soft X-ray Spectrometer (CLASS) instrument and China's Hard X-ray Modulation Telescope (HXMT). Measurements of the Quantum Efficiency (QE) have been obtained relative to a NIST calibrated photodiode over the energy range 0.2 keV to 1.9 keV, using the BESSY II X-ray synchrotron in Berlin. Two X-ray event counting methods are described and compared, and QE for soft X-ray interaction is reported. Uniformity of QE across the device is also investigated at energies between 0.52 keV and 1.5 keV in different areas of the detector. This work will enable the actual number of photons incident on the detectors to be calculated, thus ensuring that the CCD236 detectors provide valuable scientific data during use. By comparing the QE methods in this paper with the event processing techniques to be used with CLASS, an estimate of the instrument-specific QE for CLASS can be provided.

Smith, P. H.; Gow, J. P. D.; Murray, N. J.; Tutt, J. H.; Soman, M. R.; Holland, A. D.

2014-04-01

378

Silicon-On-Insulator (SOI) Devices and Mixed-Signal Circuits for Extreme Temperature Applications  

NASA Technical Reports Server (NTRS)

Electronic systems in planetary exploration missions and in aerospace applications are expected to encounter extreme temperatures and wide thermal swings in their operational environments. Electronics designed for such applications must, therefore, be able to withstand exposure to extreme temperatures and to perform properly for the duration of the missions. Electronic parts based on silicon-on-insulator (SOI) technology are known, based on device structure, to provide faster switching, consume less power, and offer better radiation-tolerance compared to their silicon counterparts. They also exhibit reduced current leakage and are often tailored for high temperature operation. However, little is known about their performance at low temperature. The performance of several SOI devices and mixed-signal circuits was determined under extreme temperatures, cold-restart, and thermal cycling. The investigations were carried out to establish a baseline on the functionality and to determine suitability of these devices for use in space exploration missions under extreme temperatures. The experimental results obtained on selected SOI devices are presented and discussed in this paper.

Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik

2008-01-01

379

Transient temperature measurements and modeling of IGBT's under short circuit  

Microsoft Academic Search

This paper discusses the estimation of possible device destruction inside power converters in order to predict failures by means of simulation. The study of insulated gate bipolar transistor (IGBT) thermal destruction under short circuits is investigated. An easy experimental method is presented to estimate the temperature decay in the device from the saturation current response at low gate-to-source voltage during

Anis Ammous; Bruno Allard; Herve Morel

1998-01-01

380

Cloud and surface classification using SCIAMACHY polarization measurement devices  

NASA Astrophysics Data System (ADS)

A simple scheme has been developed to discriminate surface, sun glint and cloud properties in satellite based spectrometer data utilizing visible and near infrared information. It has been designed for the use with data measured by SCIAMACHY's (SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY) Polarization Measurement Devices (PMD) but the applicability is not strictly limited to this instrument. The scheme is governed by a set of constraints and thresholds developed by using satellite imagery and meteorological data. Classification targets are ice, water and generic clouds, sun glint and surface parameters, such as water, land, snow/ice, desert and vegetation. The validation has been done using MERIS (MEdium Resolution Imaging Spectrometer) and meteorological data from METAR (MTorologique Aviation Rgulire - a network for the provision of meteorological data for aviation). Qualitative validation using MERIS satellite imagery shows good agreement. However, the quantitative agreement is hampered by the heterogeneity of MERIS classifications within each SCIAMACHY PMD ground pixel. The comparison with METAR data shows good agreement. The comparison for sun glint classifications and MERIS results exhibits excellent agreement.

Lotz, W. A.; Vountas, M.; Dinter, T.; Burrows, J. P.

2009-02-01

381

Skin friction measurements in high temperature high speed flows  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted to measure skin friction along the chamber walls of supersonic combustors. A direct force measurement device was used to simultaneously measure an axial and transverse component of the small tangential shear force passing over a non-intrusive floating element. The floating head is mounted to a stiff cantilever beam arrangement with deflection due to the flow on the order of 0.00254 mm (0.0001 in.). This allowed the instrument to be a non-nulling type. A second gauge was designed with active cooling of the floating sensor head to eliminate non-uniform temperature effects between the sensor head and the surrounding wall. Samples of measurements made in combustor test facilities at NASA Langley Research Center and at the General Applied Science Laboratory (GASL) are presented. Skin friction coefficients between 0.001 - 0.005 were measured dependent on the facility and measurement location. Analysis of the measurement uncertainties indicate an accuracy to within +/- 10-15 percent of the streamwise component.

Schetz, J. A.; Diller, Thomas E.; Wicks, A. L.

1992-01-01

382

Simulated limnological effects of the Shasta Lake temperature control device  

USGS Publications Warehouse

Population ecologists have devoted disproportionate attention to the estimation and study of birth and death rates and far less effort to rates of movement. Movement and fidelity to wintering areas have important ecological and evolutionary implications for avian populations. Previous inferences about movement among and fidelity to wintering areas have been restricted by limitations of data and methodology. We use multiple observation data from a large-scale capture-resighting study of Canada Geese in the Atlantic flyway to estimate probabilities of returning to previous wintering locations and moving to new locations. Mark-resight data from 28,849 Canada Geese (Branta canadensis) banded woth individually coded neck bands in the mid-Atlantic (New York, Pennsylvania, New Jersey), Chesapeake (Delaware, Maryland, Virginia), and Carolinas (North and South Carolina) were used to estimate movement and site-fidelity. Two three-sample mark-resight models were developed and programmed using SURVIV to estimate the probability of moving among or remaining within these three wintering regions. The model (MV2) that incorporated tradition' or memory of previous wintering regions fit the data better than the model (MV1) that assumes that a first-order Markov chain described movement among regions. Considerable levels of movement occured among regions of the Atlantic flyway. The annual probability of remaining in the same region for two successive winters, used as a measure of site fidelity, was 0.710 plus or minus 0.016 (estimated mean plus or minus SE, 0.889 plus or minus 0.006, and 0.562 plus or minus 0.025, for the mid-Atlantic, Chesapeake, and Carolinas, respectively. The estimated probability of moving between years corresponded to changes in winter harshness. In warm years, geese moved north and in cold years, they moved south. Geese had a high probability of moving to and remaining in the Chesapeake. Annual changes in the movement probabilities did not correspond to annual changes in the United States Fish and Wildlife midwinter survey. Considerable numbers of geese from the Carolinas appeared to be wintering in more northerly locations (short-stopped) in subsequent winters.

Bartholow, J.; Hanna, R.B.; Saito, L.; Lieberman, D.; Horn, M.

2001-01-01

383

Apparatus for accurately measuring high temperatures  

SciTech Connect

The present invention is a thermometer used for measuring furnace temperatures in the range of about 1800/sup 0/ to 2700/sup 0/ C. The thermometer comprises a broadband multicolor thermal radiation sensor positioned to be in optical alignment with the end of a blackbody sight tube extending into the furnace. A valve-shutter arrangement is positioned between the radiation sensor and the sight tube and a chamber for containing a charge of high pressure gas is positioned between the valve-shutter arrangement and the radiation sensor. A momentary opening of the valve shutter arrangement allows a pulse of the high gas to purge the sight tube of air-borne thermal radiation contaminants which permits the radiation sensor to accurately measure the thermal radiation emanating from the end of the sight tube.

Smith, D. D.

1985-06-25

384

Measuring blood pressure in pregnancy and postpartum: assessing the reliability of automated measuring devices.  

PubMed

Objective: To determine the reliability of automated blood pressure (BP) measuring devices in hypertensive pregnancies. Methods: Three sequential measurements were taken using mercury sphygmomanometry and an automated device in pregnant hypertensive women (n?=?89). Results: Systolic BP (SBP) was higher with the automated device (mean difference 2.5?mmHg, 95% CI: 1.9-3.2?mmHg), whereas diastolic BP (DBP) was higher with the mercury sphygmomanometer (mean difference 2.0?mmHg, 95% CI: 1.5-2.6?mmHg). Within-patient variability for the automated device was: SBP 4.8?mmHg (95% CI: 4.6-5.2?mmHg), DBP 3.4?mmHg (95% CI: 3.1-3.7?mmHg); and for mercury sphygmomanometry: SBP 3.7?mmHg (95% CI: 3.5-4.0?mmHg), DBP 3.0?mmHg (95% CI: 2.8-3.3?mmHg). Conclusion: Outpatient automated BP measurement agrees well with mercury sphygmomanometry in hypertensive pregnancies. PMID:24304096

Lan, Patrick G; Clayton, Philip A; Hyett, Jon; Gillin, Adrian G

2014-05-01

385

Device and method for the measurement of depth of interaction using co-planar electrodes  

DOEpatents

A device and method for measuring a depth of interaction of an ionizing event and improving resolution of a co-planar grid sensor (CPG) are provided. A time-of-occurrence is measured using a comparator to time the leading edge of the event pulse from the non-collecting or collecting grid. A difference signal between the grid signals obtained with a differential amplifier includes a pulse with a leading edge occurring at the time-of-detection, measured with another comparator. A timing difference between comparator outputs corresponds to the depth of interaction, calculated using a processor, which in turn weights the difference grid signal to improve spectral resolution of a CPG sensor. The device, which includes channels for grid inputs, may be integrated into an Application Specific Integrated Circuit. The combination of the device and sensor is included. An improved high-resolution CPG is provided, e.g., a gamma-ray Cadmium Zinc Telluride CPG sensor operating at room temperature.

DeGeronimo, Gianluigi (Syosset, NY)

2007-09-18

386

Development and Implementation of a Rear Vision Device Test Protocol. Volume 1. Physical Characteristics Measurement.  

National Technical Information Service (NTIS)

A standardized method for evaluating rear vision devices was developed and implemented. The method consists of the (1) measurement of device physical characteristics including; field of view, magnification, radius of curvature, accommodation demands and r...

W. J. Burger D. Ziedman

1987-01-01

387

Precision quantum Hall resistance measurement on epitaxial graphene device in low magnetic field  

NASA Astrophysics Data System (ADS)

Precision quantum Hall resistance (QHR) measurements were performed on large-area epitaxial graphene device at temperature T = 1.5 K and at magnetic fields B from 8 T down to 2.5 T, that is much lower than typically used in precision QHR measurement. QHR was measured using cryogenic current comparator resistance bridge with relatively large biasing current Isd = 41 ?A to reduce measurement uncertainty. The results showed that at B = 8 T, the relative deviation of Hall resistance from the expected quantized value h/2e2 is within experimental uncertainty of 3.5 parts in 108 and remained below 0.35 parts per million (ppm) down to B = 3 T.

Satrapinski, A.; Novikov, S.; Lebedeva, N.

2013-10-01

388

Two-sided laser device for online paper caliper measurement and control  

NASA Astrophysics Data System (ADS)

Strong demand exists for a non-contacting paper caliper measurement which can be used as an input to a paper thickness control system. Caliper sensors requiring sheet contact suffer from errors related to dirt or coating build up and from high maintenance costs related to wear. These sensors can also damage the product by picking holes and marking sheets. Details of an on-line measurement device which employs two opposed laser displacement sensors and an inductive displacement sensor are presented. The sheet is held perpendicularly to the sensors with a Coanda air clamp. Dust and temperature control features which enable the sensor to operate reliably in an industrial environment are discussed. Results of production trials of this sensor are presented. Sub-micron profile agreement to lab and contacting caliper measurements has been demonstrated on light sheets. Results are presented of measurements on a wide range of paper grades from coated and uncoated light sheets to coated board.

Hughes, Michael K. Y.; Bengtsson, Markus; Hui, Pak; Duck, Graham

2009-06-01

389

Low Temperature Probe for Measuring Anisotropic Magnetotransport  

NASA Astrophysics Data System (ADS)

Certain materials display a change in resistance when a magnetic field is applied on them. This resistance change is called magnetoresistance (MR). The value of MR may also depend on the direction of the magnetic field relative to the crystal structure of the material, which is called anisotropic MR (AMR). We built a probe which allows us to measure the AMR of a sample in a temperature range of 1.2 K to 300K in magnetic fields of up to 9 tesla. The probe design allows the angle between the magnetic field and a particular direction of the sample to be changed over almost the entire solid angle of 4?. In particular, this probe lets us measure the AMR of a sample with magnetic anisotropy when the magnetic field is applied either along the hard or easy axes, or somewhere in between. The probe allows us to change the orientation of the sample while it is inside the low temperature cryostat. We will present our data on hole-doped manganese oxide (manganite) thin films and discuss the possible origins of AMR in these materials.

Dragiev, Galin; Grant, Daniel; Biswas, Amlan

2013-03-01

390

Monitoring the junction temperature of an IGBT through direct measurement using a fiber Bragg grating  

NASA Astrophysics Data System (ADS)

This paper proposes a new technique to monitor the junction temperature of an insulated gate bipolar transistor (IGBT) through direct measurement using an optical fiber sensor mounted on the chip structure. Some features of the sensor such as electromagnetic immunity, small size and fast response time allow the identification of temperature changes generated by the energy loss during device operation. In addition to the online monitoring of the junction temperature, results show the thermal characteristics of the IGBT, which can be used to develop an accurate model to simulate the heat generated during the device conduction and switching processes.

Bazzo, Joo P.; Lukasievicz, Tiago; Vogt, Marcio; de Oliveira, Valmir; Kalinowski, Hypolito J.; Cardozo da Silva, Jean Carlos

2011-05-01

391

Ion temperature and radial profile of CII-CV located in the edge and divertor plasmas of large helical device  

NASA Astrophysics Data System (ADS)

Space-resolved vacuum ultraviolet (VUV) spectroscopy using a 3-m normal incidence spectrometer is utilized to measure the impurity emission profile in the edge and divertor plasmas of the Large Helical Device (LHD). It measures the vertical profile of VUV lines emitted in the wavelength range of 300-3200 A. CII, CIII, CIV, and CV lines emitted from carbon ions are successfully measured, and their ion temperatures are derived from the Doppler broadening. Vertical profiles of the emission intensity and the ion temperature are measured simultaneously for the CIV line. The emission intensity profile, which has several peak structures, is reasonably explained by considering the relation between the C3+ ion distribution and the geometry used for the observations.

Oishi, Tetsutarou; Morita, Shigeru; Dong, Chunfeng; Goto, Motoshi; Wang, Erhui; Huang, Xianli

2014-03-01

392

Albedo effect on radiative errors in air temperature measurements  

Microsoft Academic Search

Most standard air temperature measurements are subject to significant errors mainly due to sensor heating by solar radiation, even when the measurement principle is accurate and precise. We present various air temperature measurements together with other measurements of meteorological parameters using different sensor systems at a snow-covered and a vegetated site. Measurements from naturally ventilated air temperature sensors in multiplate

Hendrik Huwald; Chad W. Higgins; Marc-Olivier Boldi; Elie Bou-Zeid; Michael Lehning; Marc B. Parlange

2009-01-01

393

Gas thermometer for precision measurement of thermodynamic temperatures below 300/sup 0/K  

SciTech Connect

The authors discuss an apparatus for measuring thermodynamic temperatures of 3-300/sup 0/K by means of a constant-density gas thermometer. The main measuring device in the gas thermometer is a special mercury interference manometer. The flow cryostat for the range 2-300/sup 0/K is shown and the heat carriers are liquid or gaseous helium, hydrogen, and nitrogen. The thermodynamic temperatures measured by this thermometer have been transferred to several standard resistance thermometers made of platinum and rhodium-iron alloy. The gas thermometer examined here enables the measurement of temperatures on the thermodynamic scale with an error of not more than 1 mK.

Polunin, S.P.; Astrov, D.N.; Belyanskii, L.B.; Dedikov, Yu.A.; Zakharov, A.A.

1987-08-01

394

Development of a modulator pulse stability measurement device and test results at SLAC  

Microsoft Academic Search

In this paper, the development of a pulse stability measurement device is presented. The measurement accuracy is better than 250uV, about 4.2ppm of a typical 60V input pulse. Pulse signals up to +\\/? 80V peak can be measured. The device works together with an oscilloscope. The primary function of the measurement device is to provide a precision offset, such that

C. Huang; C. Burkhart; M. Kemp; B. Morris; T. Beukers; R. Ciprian; M. Nguyen

2011-01-01

395

Device Performance  

SciTech Connect

In the Device Performance group, within the National Center for Photovoltaic's Measurements and Characterization Division, we measure the performance of PV cells and modules with respect to standard reporting conditions--defined as a reference temperature (25 C), total irradiance (1000 Wm-2), and spectral irradiance distribution (IEC standard 60904-3). Typically, these are ''global'' reference conditions, but we can measure with respect to any reference set. To determine device performance, we conduct two general categories of measurements: spectral responsivity (SR) and current versus voltage (I-V). We usually perform these measurements using standard procedures, but we develop new procedures when required by new technologies. We also serve as an independent facility for verifying device performance for the entire PV community. We help the PV community solve its special measurement problems, giving advice on solar simulation, instrumentation for I-V measurements, reference cells, measurement procedures, and anomalous results. And we collaborate with researchers to analyze devices and materials.

Not Available

2006-06-01

396

Development of nickel aluminide microchannel array devices for high-temperature applications  

NASA Astrophysics Data System (ADS)

The miniaturization of Microtechnology-based Energy, Chemical and Biological Systems (MECS) is made possible by the use of high aspect ratio microchannel arrays to increase the surface-area-to-volume ratio of the flow conduits within the devices, resulting in an improvement in the heat and mass transfer performance of the devices. However, advantages of the MECS concept cannot be applied to high-temperature applications (above 650C) due to lack of high-temperature MECS devices; therefore, the development of high-temperature MECS devices is necessary to overcome this bottleneck. This dissertation involves the development of high-temperature MECS devices from a high-temperature material, nickel aluminide (NiAl). NiAl foil was synthesized from elemental nickel (Ni) and aluminum (Al) foils through a two step process---tack bonding and reactive diffusion. The elemental foils were tack bonded at 500C, 3.9 MPa for 15 minutes. The reactive diffusion process was then performed through a heat treatment at 1000C for a period of time corresponding to the thickness of the composite foil. The synthesized NiAl foil showed an atomic ratio of Al to Ni up to 0.96. The foil also showed a decent flatness and surface roughness. This dissertation proposes a reactive diffusion bonding as a joining technique of nickel aluminides. An investigation of bonding parameter effects on the warpage of nickel aluminide fins in the reactive diffusion bonding process was performed. Results showed that bonding time and temperature had significant effects on warpage of the fin. The fin warpage increased with the increase of bonding time and bonding temperature. Results also suggested that the bonding pressure had an effect on the fin warpage. However, chemical compositions of the fin were not significant to the warpage. This research also proposes a new fabrication procedure for producing NiAl MECS devices. NiAl foils were used as the starting material, and the reactive diffusion bonding technique was employed as the joining technique. The research outcome indicated the viability of the proposed method in fabricating NiAl MECS devices. This method achieved leak-tight devices with a reasonable fin flatness.

Kanlayasiri, Kannachai

397

Probabilistic Design Optimization and Reliability Assessment of High Temperature Thermoelectric Devices  

SciTech Connect

Thermoelectric (TE) devices, subcomponents of which are made of brittle materials, generate an electrical potential when they are subjected to thermal gradients through their thickness. These devices are of significant interest for high temperature environments in transportation and industrial applications where waste heat can be used to generate electricity (also referred to as "waste heat recovery" or "energy harvesting"). TE devices become more efficient as larger thermal gradients are applied across them. This is accomplished by larger temperature differences across the TE's hot and cold junctions or the use of low thermal conductivity TE materials or both. However, a TE brittle material with a combination of poor strength, low thermal conductivity, and large coefficient of thermal expansion can translate into high probability of mechanical failure (low reliability) in the presence of a thermal gradient, thereby preventing its use as intended. Therefore, the objective of this work is to demonstrate the use of an established probabilistic design methodology developed for brittle structural components and corresponding design sensitivity analyses to optimize the reliability of an arbitrary TE device. This method can be used to guide TE material and design selection for optimum reliability. The mechanical reliability of a prototypical TE device is optimized from a structural ceramic perspective, using finite element analysis and the NASA CARES/Life integrated design code. Suggested geometric redesigns and material selection are identified to enhance the reliability of the TE device.

Jadaan, Osama M. [University of Wisconsin, Platteville; Wereszczak, Andrew A [ORNL

2008-01-01

398

Imaging photorefractive optical vibration measurement method and device  

DOEpatents

A method and apparatus are disclosed for characterizing a vibrating image of an object of interest. The method includes providing a sensing media having a detection resolution within a limited bandwidth and providing an object of interest having a vibrating medium. Two or more wavefronts are provided, with at least one of the wavefronts being modulated by interacting the one wavefront with the vibrating medium of the object of interest. The another wavefront is modulated such that the difference frequency between the one wavefront and the another wavefront is within a response range of the sensing media. The modulated one wavefront and another wavefront are combined in association with the sensing media to interfere and produce simultaneous vibration measurements that are distributed over the object so as to provide an image of the vibrating medium. The image has an output intensity that is substantially linear with small physical variations within the vibrating medium. Furthermore, the method includes detecting the image. In one implementation, the apparatus comprises a vibration spectrum analyzer having an emitter, a modulator, sensing media and a detector configured so as to realize such method. According to another implementation, the apparatus comprises a vibration imaging device.

Telschow, Kenneth L. (Idaho Falls, ID); Deason, Vance A. (Idaho Falls, ID); Hale, Thomas C. (Los Alamos, NM)

2000-01-01

399

Absorption measurements in microfluidic devices using ring-down spectroscopy  

NASA Astrophysics Data System (ADS)

When monitoring separation events in microfluidic devices, one frequently needs to detect small amounts of analyte in picolitre sized volumes with a time response of milliseconds. Fluorescence detection is typically the method of choice due to its very high sensitivity and fast response. However, since many analytes are not naturally fluorescent, labelling protocols may have to be introduced and thereby increase the complexity of the analysis. Here, we present an alternative method that is based on optical absorption, or more specifically on the ring-down time of an optical signal in a cavity or loop made of waveguide material. This optical decay constant changes as small liquid samples containing absorbing species are introduced into a fiber-optic loop. It is demonstrated that one can obtain the optical decay constant using a continuous wave laser beam that is intensity modulated and then coupled into an optical fiber loop. The inherent exponential decay in the fiber loop introduces a phase shift of the light emitted from the loop with respect to the pumping beam. By measuring this phase shift, one can readily determine the concentration of the analyte introduced between the two fiber ends and a model is established to describe the relationship. It is demonstrated that this technique, dubbed "phase-shift fiber-loop ring-down spectroscopy" (PS-FLRDS), is well suited as an absorption detector for any flow system in which the optical absorption path is limited by the instrument architecture.

Trefiak, Nicholas R.; Barnes, Jack; Rask, Fiona; Courtney, Daniel G.; Walford, Richard; Li, Runkai; Oleschuk, Richard D.; Loock, Hans-Peter

2005-09-01

400

Measurements of brake disc surface temperature and emissivity by two-color pyrometry  

Microsoft Academic Search

A fiber optic two-color pyrometer was developed for brake disc surface temperature and emissivity measurements. The two-color pyrometer consists of a fluoride glass optical fiber, two HgCdTe detectors equipped with bandwidth filters and a data conditioning and acquisition device. The two-color pyrometer measures the brake disc temperature in the 200800C range with a time resolution of 8?s. The calibration formula

Jean Thevenet; Monica Siroux; Bernard Desmet

2010-01-01

401

Measurement and structural invariance of the Antisocial Process Screening Device.  

PubMed

Despite increasing study of psychopathic traits in children and adolescents, evidence regarding the factor structure of these traits has been inconsistent across community, clinic-referred, and incarcerated samples. Empirical support exists for both 2-factor (Impulsivity-Conduct Problems and Callous-Unemotional) and 3-factor (Narcissism, Callous-Unemotional, and Impulsivity) models, and factorial invariance across various samples has not been either tested or supported in the extant literature. We conducted confirmatory factor analyses of the Antisocial Process Screening Device (APSD; Frick & Hare, 2001) in 838 nonreferred twin pairs (M = 10.57 years, SD = 3.19 years) and 251 clinic-referred children (M = 10.82 years, SD = 3.39 years). Factorial invariance was tested across zygosity (monozygotic vs. dizygotic twins), sex (males vs. females), and age (younger vs. older children, divided by median age of 10.37 years) in the community sample and across sample type in both the community and clinic-referred samples. Results suggested that the 3-factor model fit better than did the 2-factor model in both community and clinic-referred samples. Using the best fitting 3-factor model, full measurement and structural invariance were found across zygosity, sex, and age in the community sample. Full measurement and structural invariance were also found across sample type except for differences in factor means across samples, suggesting excellent psychometric properties of the APSD. These results strongly support the robustness of the 3-factor model of psychopathic traits in children as well as the generalizability of the APSD across samples. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:24274050

Dong, Lu; Wu, Hao; Waldman, Irwin D

2014-06-01

402

INNOVATIVE INSTRUMENTATION AND ANALYSIS OF THE TEMPERATURE MEASUREMENT FOR HIGH TEMPERATURE GASIFICATION  

SciTech Connect

The systematic tests of the gasifier simulator on the clean thermocouple were completed in this reporting period. Within the systematic tests on the clean thermocouple, five (5) factors were considered as the experimental parameters including air flow rate, water flow rate, fine dust particle amount, ammonia addition and high/low frequency device (electric motor). The fractional factorial design method was used in the experiment design with sixteen (16) data sets of readings. Analysis of Variances (ANOVA) was applied to the results from systematic tests. The ANOVA results show that the un-balanced motor vibration frequency did not have the significant impact on the temperature changes in the gasifier simulator. For the fine dust particles testing, the amount of fine dust particles has significant impact to the temperature measurements in the gasifier simulator. The effects of the air and water on the temperature measurements show the same results as reported in the previous report. The ammonia concentration was included as an experimental parameter for the reducing environment in this reporting period. The ammonia concentration does not seem to be a significant factor on the temperature changes. The linear regression analysis was applied to the temperature reading with five (5) factors. The accuracy of the linear regression is relatively low, which is less than 10% accuracy. Nonlinear regression was also conducted to the temperature reading with the same factors. Since the experiments were designed in two (2) levels, the nonlinear regression is not very effective with the dataset (16 readings). An extra central point test was conducted. With the data of the center point testing, the accuracy of the nonlinear regression is much better than the linear regression.

Seong W. Lee

2004-10-01

403

Conductance Fluctuation and Superconducting-to-Normal State Switching Measurements of Superconducting Graphene Devices  

NASA Astrophysics Data System (ADS)

We report on gate voltage dependent conductance fluctuations (CF) in superconducting graphene devices and compare measurements in the superconducting versus normal state at temperatures down to 20 mK. The CF arise from the averaged interference of charge carrier wave functions caused by scattering in the graphene. An enhancement in the magnitude of the average CF is expected when in the superconducting state due to Andreev reflections. We fabricate devices by contacting graphene with two parallel superconducting leads that are spaced a few hundred nanometers apart. The leads are a Pd/Al or Ti/Al bilayer with the thin Pd or Ti layer providing high transparency contact to graphene. Additionally, we report on our ongoing superconducting-to-normal state switching measurements in graphene Josephson junctions. The distribution of the stochastic switching current gives insight into the dynamics of the junction such as the phase particle escape mechanisms and dissipation processes. The use of graphene as the weak link allows novel control of the critical current, and thus the dynamics of the junction. By gathering switching data, we can study the modified Josephson washboard potential in these devices (J. G. Lambert, et al., IEEE Trans. in Appl. Supercond. 21, 734 (2011)).

Lambert, Joseph; Carabello, Steven; Ramos, Roberto

2013-03-01

404

STP Temperature Measurement Ideal Gas Program  

NSDL National Science Digital Library

The STP DemonIdealGas program displays a histogram of the energy of a demon that exchanges energy with an ideal gas of particles. The purpose of this simulation is to understand why the demon acts as a perfect thermometer and why its mean energy is a measure of the temperature of the gas. The default system is a one-dimensional ideal gas of N=40 particles. Additional states and parameters can be specified using the Display|Switch GUI menu item. STP DemonIdealGas is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double-clicking the stp_DemonIdealGas.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2008-05-28

405

The controlling effect of temperature in the application of permeation tube devices in standard gas generation.  

PubMed

In this study, the performance of permeation tube (PT) devices for the generation of VOC calibration gas was examined by successively generating BTX gas at five temperatures (30, 50, 70, 80, and 100 C) and two flow rates (400 and 800 mL min?). A distinct relationship was observed between temperatures and permeation rates (PR) (or generated BTX concentrations). We examined the reliability of the manufacturer's PR formula when operating at chamber temperatures different from the manufacturer reference temperatures for each PT device. Bias of the actual PR from the theoretical PR values became significant as PT devices were operated at temperatures beyond their optimum operating range (e.g., maximum bias of BTX as 141%, 87.2%, and 85%, respectively). Through a derivation of empirical formula, we were able to predict PR values of the target compounds more accurately as evidenced by significant bias reduction at all temperature points (e.g., maximum bias of BTX as 10.9%, 21.1% and 20.6%, respectively). PMID:22244159

Susaya, Janice; Kim, Ki-Hyun; Cho, Jinwoo; Parker, David

2012-02-17

406

Silicon-on-insulator technology for high temperature metal oxide semiconductor devices and circuits  

Microsoft Academic Search

The high temperature characteristics of devices and circuits realized in complementary metal oxide semiconductor (CMOS) technology on silicon-on-insulator (SOI) substrates are compared with other materials, and it is demonstrated that CMOS on SOI is presently the most suitable process for the realization of electronic circuits operating at up to more than 300 C.

Denis Flandre

1995-01-01

407

Development of a Real-Time Temperature and Voltage Monitoring System for Semiconductor Devices  

Microsoft Academic Search

This paper presents the design and development of a real-time temperature and voltage monitoring system. It is developed for the purpose of monitoring and controlling semiconductor component devices which are very heat sensitive in industry-based applications. This prototype not only involves the development of the software for monitoring purposes but also includes the development of a special electronic hardware designed

Nazlia Omar; Rozli Zulkifli

2009-01-01

408

Indium arsenide quantum well hall devices for room-temperature detection of magnetic biomolecular labels  

NASA Astrophysics Data System (ADS)

This dissertation presents work on fabrication and room-temperature characterization of mesoscopic Hall sensors from InAs/AlSb quantum well semiconductor heterostructures. It also demonstrates suitability of these devices for detection of micro- and submicrometer-sized superparamagnetic beads that can be used as biomolecular labels in the newly proposed concept of magnetic biomolecular sensing. Detailed analytical analysis of physical factors which determine the magnetic field and the magnetic moment resolution of cross-shaped Hall sensors is presented. The analysis shows that materials with low Hooge's 1/f noise parameter, low density of active charge traps, high carrier mobility and, contrary to the common opinion, high electron density provide the best physical medium for fabricating ultra-sensitive miniaturized Hall sensors. Systematic room-temperature Hall coefficient and electronic noise measurements have been carried out on the sensors with the Hall cross widths of 1 mum and 250 nm. In the low frequency range, from 20 Hz to 1.6 kHz, the sensors show magnetic moment sensitivities on the order of 106 mu B/ Hz and 105 muB/ Hz respectively, where muB is the Bohr magneton. For 250 nm devices, the moment sensitivity reaches the values in 104 muB/ Hz range above 1 kHz. By using phase-sensitive detection technique based on non-linear magnetization response of superparamagnetic beads to external magnetic field, the presence of a single bead, 1.2 mum in diameter and suitable for biological applications, on the micron-sized Hall cross has been detected with signal to noise ratio of 33.3 dB. Micro-Hall susceptibility measurements and the subsequent data analysis have shown that the bead consists of ensemble of non-interacting magnetic nanoparticles with broad distribution of magnetic moments. The mean magnetic moment and the mean diameter of nanoparticles in the bead were found to be 1.55 x 104 mu B and 8.3 nm respectively. Additionally, detection of 250 nm beads has been achieved with signal to noise ratio of 2.3 dB per single bead.

Mihajlovic, Goran

409

Simultaneous directional bending and temperature measurement with overlapping long period grating and fiber Bragg grating structure  

NASA Astrophysics Data System (ADS)

A simple and compact device for simultaneous directional bending and temperature sensing is proposed and demonstrated. The device is constructed by overlapping a long period grating (LPG) on a fiber Bragg grating (FBG), and is capable of measuring the directional bending and the temperature at the same position. The LPG written with CO2 laser irradiation has a cross asymmetrical refractive modulation and the FBG is formed by UV laser exposure in the fiber core. The cross-sensitivity between measurement of the directional bending and of the temperature of an LPG is effectively eliminated by solving a matrix equation, by considering the temperature response characteristics of FBG. Experimental results show that the bending and temperature sensitivities are ? 6.819 nm m?1 in a range from ?2 to 2 m?1 and 10.25 pm C?1, respectively.

Wang, Li; Zhang, Weigang; Geng, Pengcheng; Gao, Shecheng; Li, Jieliang; Bai, Zhiyong; Chen, Lei; Zhang, Shanshan; Liu, Yongji; Yan, Tieyi

2014-05-01

410

An evaluation of milk temperature measurement for detecting oestrus in dairy cattle. I factors affecting measurement of milk temperature  

Microsoft Academic Search

The paper reports the development of an electronic system of milk temperature measurement and the results of investigations into the influence of milk yield, milk flow and ambient temperature on milk temperature. The milk and body temperatures of randomly selected multiparous Friesian cows were recorded at afternoon milkings. Temperature was measured by bead thermistors housed in perspex probes from which

D. P. Fordham; T. T. McCarthy; P. Rowlinson

1987-01-01

411

Technique for calibrating angular measurement devices when calibration standards are unavailable  

NASA Technical Reports Server (NTRS)

A calibration technique is proposed that will allow the calibration of certain angular measurement devices without requiring the use of absolute standard. The technique assumes that the device to be calibrated has deterministic bias errors. A comparison device must be available that meets the same requirements. The two devices are compared; one device is then rotated with respect to the other, and a second comparison is performed. If the data are reduced using the described technique, the individual errors of the two devices can be determined.

Finley, Tom D.

1991-01-01

412

Ultrasonic database development for the acoustic inspection device: the velocity-attenuation measurement system (VAMS)  

NASA Astrophysics Data System (ADS)

The inspection of sealed containers is a critical task for personnel charged with enforcing government policies, maintaining public safety, and ensuring national security. The Pacific Northwest National Laboratory (PNNL) has developed a portable, handheld acoustic inspection device (AID) that provides non-invasive container interrogation and material identification capabilities. The AID technology has been deployed worldwide and user"s are providing feedback and requesting additional capabilities and functionality. Recently, PNNL has developed a laboratory-based system for automated, ultrasonic characterization of fluids to support database development for the AID. Using pulse-echo ultrasound, ultrasonic pulses are launched into a container or bulk-solid commodity. The return echoes from these pulses are analyzed in terms of time-of-flight and frequency content (as a function of temperature) to extract physical property measurements (acoustic velocity and attenuation) of the material under test. These measured values are then compared to a tailored database of materials and fluids property data acquired using the Velocity-Attenuation Measurement System (VAMS). This bench-top platform acquires key ultrasonic property measurements as a function of temperature and frequency. This paper describes the technical basis for operation of the VAMS, recent enhancements to the measurement algorithms for both the VAMS and AID technologies, and new measurement data from laboratory testing and performance demonstration activities. Applications for homeland security and counterterrorism, law enforcement, drug-interdiction and fuel transportation compliance activities will be discussed.

Diaz, Aaron A.; Burghard, Brion J.; Valencia, Juan D.; Samuel, Todd J.

2004-07-01

413

Ultrasonic database development for the acoustic inspection device: the velocity-attenuation measurement system (VAMS)  

SciTech Connect

The inspection of sealed containers is a critical task for personnel charged with enforcing government policies, maintaining public safety, and ensuring national security. The Pacific Northwest National Laboratory (PNNL) has developed a portable, handheld acoustic inspection device (AID) that provides non-invasive container interrogation and material identification capabilities. The AID technology has been deployed worldwide and user's are providing feedback and requesting additional capabilities and functionality. Recently, PNNL has developed a laboratory-based system for automated, ultrasonic characterization of fluids to support database development for the AID. Using pulse-echo ultrasound, ultrasonic pulses are launched into a container or bulk-solid commodity. The return echoes from these pulses are analyzed in terms of time-of-flight and frequency content (as a function of temperature) to extract physical property measurements (acoustic velocity and attenuation) of the material under test. These measured values are then compared to a tailored database of materials and fluids property data acquired using the Velocity-Attenuation Measurement System (VAMS). This bench-top platform acquires key ultrasonic property measurements as a function of temperature and frequency. This paper describes the technical basis for operation of the VAMS, recent enhancements to the measurement algorithms for both the VAMS and AID technologies, and new measurement data from laboratory testing and performance demonstration activities. Applications for homeland security and counter terrorism, law enforcement, drug-interdiction and fuel transportation compliance activities will be discussed.

Diaz, Aaron A.; Burghard, Brion J.; Valencia, Juan D.; Samuel, Todd J.; Doctor, S. R.

2004-08-01

414

Device Measurement and Modeling System for Electronic Terahertz Sensing.  

National Technical Information Service (NTIS)

This proposal was for acquisition of an advanced semiconductor device modeling system to characterize transistors, diodes and passive element from 45 MHz to at least 110 GHz to enable design and development of advanced electronic terahertz sensing systems...

D. W. VAN DER Weide

2003-01-01

415

A prototype wireless inertial-sensing device for measuring toe clearance.  

PubMed

Tripping and slipping are serious health concerns for the elderly because they result in life threatening injuries i.e., fractures and high medical costs. Our recent work in detection of tripping gait patterns has demonstrated that minimum toe clearance (MTC) is a sensitive falls risk predictor. MTC measurement has previously been done in gait laboratories and on treadmills which potentially imposes controlled walking conditions. In this paper, we describe a prototype design of a wireless device for monitoring vertical toe clearance. The sensors consists of a tri-axis accelerometer and dual-axis gyroscope connected to Crossbow sensor motes for wireless data transmission. Sensor data are transmitted to a laptop and displayed on a Matlab graphic user interface (GUI). We have performed zero base and treadmill experiments to investigate sensor performance to environmental variations and compared the calculated toe clearance against measurements made by an Optotrak motion system. It was found that device outputs were approximately independent of small ambient temperature variations, had a reliable range of 20m indoors and 50m outdoors and a maximum transmission rate of 20 packets/s. Toe clearance measurements were found to follow the Optotrak measurement trend but could be improved further by dealing with double integration errors and improving data transmission rates. PMID:19163815

Lai, Daniel T H; Charry, E; Begg, R; Palaniswami, M

2008-01-01

416

Magnetic Susceptibility Measurements at Ultra-low Temperatures  

Microsoft Academic Search

We report the design and operation of a device for ac magnetic susceptibility measurements that can operate down to 1 mK. The device, a modification of the standard mutual inductance bridge, is designed with detailed consideration of the thermalization and optimization of each element. First, in order to reduce local heating, the primary coil is made with superconducting wire. Second,

L. Yin; J. S. Xia; N. S. Sullivan; V. S. Zapf; A. Paduan-Filho

2010-01-01

417

MOVPE growth of improved nonequilibium MCT device structures for near-ambient-temperature heterodyne detectors  

NASA Astrophysics Data System (ADS)

Cadmium mercury telluride (Hg1-xCdxTe or MCT) non- equilibrium detector structures which allow room temperature operation have been grown by metal-organic vapor phase epitaxy (MOVPE). These devices suppress the auger generation by reducing the intrinsic electron and hole concentrations in the active region of the device. The MCT characteristics in this region should then be determined by the extrinsic doping concentration. In order to minimize the remaining generation processes within this so called (pi) -region, it is best formed from low acceptor doped (low X1015 cm-3) MCT, with as low a trap density as possible. The p+(pi) n+ device structure which is required to achieve the non-equilibrium phenomena requires stringent control on acceptor and donor doping, as well as composition. Acceptor doping studies with trisdimethylamino arsine (DMAAs) have been performed using GaAs and CdZnTe substrates. Minority carrier lifetime results have been obtained which are near rotatively limited and comparable to As-doped, Hg-rich liquid phase epitaxy (LPE) grown layers on CdZnTe substrates. Ambient temperature, auger-suppressed devices have levels of 1/f noise which currently limit their use in imaging applications. However, they are of great interest in other applications such as approximately equals 10 micrometer negative luminescence emitter devices and heterodyne detection of 10.6 micrometer infrared (IR) radiation from carbon-dioxide lasers. Reduction in the series resistances has been achieved by utilizing a device design with a n+ MCT common which should improve the frequency response of these devices. Another design modification, predicted to reduce the leakage current, has been the introduction of low doped, wide band gap regions either side of the (pi) -region. In practice these structures have produced over an order of magnitude improvement in the leakage current characteristics.

Maxey, C. D.; Jones, C. L.; Metcalfe, N. E.; Catchpole, R. A.; Gordon, Neil J.; White, A. M.; Elliot, C. T.

1997-10-01

418

A Tunable Hybrid Electro-magnetomotive NEMS Device for Low Temperature Physics  

NASA Astrophysics Data System (ADS)

Microfabrication techniques have made possible the realization of mechanical devices with dimensions in the micro- and nano-scale domain. At low temperatures, one can operate and study these devices in well-controlled conditions, namely low electrical noise and cryogenic vacuum, with the ability to use high magnetic fields and superconducting coating metals (Collin et al. in J. Low Temp. Phys. 150(5-6):739, 2008). Moreover, the temperature turns out to be a control parameter in the experimental study of mechanical dissipation processes, with the cryogenic environment ensuring that only low energy states are thermally populated. Immersed in a quantum fluid, these MEMS and NEMS devices (micro and nano electro-mechanical systems) can probe the excitations of the liquid at a smaller scale, with higher frequencies and better resolution than "classical" techniques (Triqueneaux et al. in Physica B 284:2141, 2000). We present experimental results obtained in vacuum on cantilever NEMS structures which can be both magnetomotive and electrostatically driven. The device is extremely sensitive with resolved displacements down to 1 using conventional room-temperature electronics. It is calibrated in situ, and frequency/non-linearity can be tuned electrostatically. The design should allow parametric amplification to be used.

Collin, E.; Moutonet, T.; Heron, J.-S.; Bourgeois, O.; Bunkov, Yu. M.; Godfrin, H.

2011-03-01

419

Measurement Corner: Volume, Temperature and Pressure  

ERIC Educational Resources Information Center

Boyle's Law and basic relationships between volume and pressure of a gas at constant temperature are presented. Suggests two laboratory activities for demonstrating the effect of temperature on the volume of a gas or liquid. (CS)

Teates, Thomas G.

1977-01-01

420

Metallic Contaminant Detection using a High-Temperature Superconducting Quantum Interference Devices Gradiometer  

NASA Astrophysics Data System (ADS)

We develop magnetic metallic contaminant detectors using high-temperature superconducting quantum interference devices (HTS-SQUIDs) for industrial products. Finding ultra-small metallic contaminants is an important issue for manufacturers producing commercial products such as lithium ion batteries. If such contaminants cause damages, the manufacturer of the product suffers a big financial loss due to having to recall the faulty products. Previously, we described a system for finding such ultra-small particles in food. In this study, we describe further developments of the system, for the reduction of the effect of the remnant field of the products, and we test the parallel magnetization of the products to generate the remnant field only at both ends of the products. In addition, we use an SQUID gradiometer in place of the magnetometer to reduce the edge effect by measuring the magnetic field gradient. We test the performances of the system and find that tiny iron particles as small as 50 50 ?m2 on the electrode of a lithium ion battery could be clearly detected. This detection level is difficult to achieve when using other methods.

Saburo, Tanaka; Tomohiro, Akai; Makoto, Takemoto; Yoshimi, Hatsukade; Takeyoshi, Ohtani; Yoshio, Ikeda; Shuichi, Suzuki

2010-08-01

421

Time interval measurement device based on surface acoustic wave filter excitation, providing 1 ps precision and stability  

SciTech Connect

This article deals with the time interval measurement device, which is based on a surface acoustic wave (SAW) filter as a time interpolator. The operating principle is based on the fact that a transversal SAW filter excited by a short pulse can generate a finite signal with highly suppressed spectra outside a narrow frequency band. If the responses to two excitations are sampled at clock ticks, they can be precisely reconstructed from a finite number of samples and then compared so as to determine the time interval between the two excitations. We have designed and constructed a two-channel time interval measurement device which allows independent timing of two events and evaluation of the time interval between them. The device has been constructed using commercially available components. The experimental results proved the concept. We have assessed the single-shot time interval measurement precision of 1.3 ps rms that corresponds to the time of arrival precision of 0.9 ps rms in each channel. The temperature drift of the measured time interval on temperature is lower than 0.5 ps/K, and the long term stability is better than {+-}0.2 ps/h. These are to our knowledge the best values reported for the time interval measurement device. The results are in good agreement with the error budget based on the theoretical analysis.

Panek, Petr; Prochazka, Ivan [Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberska 57, 182 51 Prague (Czech Republic)

2007-09-15

422

ECH Plasma Experiments on an Internal Coil Device with a High Temperature Superconductor Coil  

SciTech Connect

Self-organization related with relaxation phenomenon is playing an important role in various aspects of magnetic confined plasmas. Recently a relaxation theory including the plasma flow has been developed by Mahajan-Yoshida, and a new relaxation state has been identified. The two-fluid relaxation condition is given by {beta} + (V/V{sub A}){sup 2} = const. To study a self-organized structure with strong plasma flow, we have introduced an internal coil device. By inducing a radial electric field with appropriate methods, we could drive a toroidal plasma flow, and confine a high beta plasma in a core region. The internal coil device Mini-RT with a high temperature superconductor(HTS) coil(Rc=0.15m, Ic=50kA) has been constructed. The vacuum chamber is 1 m in diameter and {approx}0.7 m in height. The magnetic field strength near the internal coil is around 0.1 T, and a radio-frequency wave of 2.45 GHz is applied for the plasma production. We have started ECH plasma experiments with the coil supported mechanically. The electron density, which has a peak near the internal coil, is of order 10{sup 16} m{sup -3}, reaching the cut-off density of the microwave. While, the electron temperature is of order 10 eV with a broad profile. Estimated energy confinement time is of order 10{sup -(5-6)} sec. The levitation experiment of the HTS coil has been carried out. The position of the HTS coil is measured with laser sensors, and is feedback-controlled with the levitation coil current. We have succeeded to levitating the HTS coil during one hour with an accuracy of less than 20 {omega}m. A preliminary experiment for the plasma production at the floating condition of the HTS coil has been initiated. It is affirmed that the levitation system works well and plasma with separatrix configuration is produced.

Ogawa, Yuichi [University of Tokyo (Japan); Morikawa, Junji [University of Tokyo (Japan); Ohkuni, Kotaro [University of Tokyo (Japan); Yamakoshi, Shigeo [University of Tokyo (Japan); Goto, Takuya [University of Tokyo (Japan); Mito, Toshiyuki [National Institute for Fusion Science (Japan); Yanagi, Nagato [National Institute for Fusion Science (Japan); Iwakuma, Masataka [Kyushu University (Japan)

2005-01-15

423

Testing and evaluation of thermal cameras for absolute temperature measurement  

Microsoft Academic Search

The accuracy of temperature measurement is the most important criterion for the evaluation of thermal cameras used in applications requiring absolute temperature measurement. All the main international metrological organizations currently propose a parameter called uncertainty as a measure of measurement accuracy. We propose a set of parameters for the characterization of thermal measurement cameras. It is shown that if these

Krzysztof Chrzanowski; Joachim Fischer; Robert Matyszkiel

2000-01-01

424

High-energy neutral particle measurement system in the large helical device  

NASA Astrophysics Data System (ADS)

The development of a high-energy neutral particle measurement system for ion temperature measurements and high-energy particle confinement analysis during neutral beam injection and ion cyclotron resonance frequency heating experiments in the large helical device (LHD) is described here. We have been improving the time-of-flight neutral particle analyzer for the LHD which had been developed in ENEA Frascati. The control and data acquisition systems were designed to be suitable for long discharges in the LHD. The horizontal and vertical movable stage is prepared to investigate pitch-angle distribution and loss cone. We have resolved many difficulties at installation, for example, the strong leakage magnetic field from the LHD and the limitations of magnetized materials near the LHD, the quench of the superconducting magnetic field, the narrow viewing port, and the fully remote control system. The preliminary results in plasma experiments are also described here.

Ozaki, Tetsuo; Zanza, Vincenzo; Bracco, Giovanni; Moleti, Arturo; Tilia, Benedetto; Sibio, Alessandro; Sudo, Shigeru; Nakanishi, Hideya; Kojima, Mamoru; Shoji, Mamoru

2000-07-01

425

Noninvasive liver-iron measurements with a room-temperature susceptometer  

Microsoft Academic Search

Magnetic susceptibility measurements on the liver can quantify iron overload accurately and noninvasively. However, established susceptometer designs, using superconducting quantum interference devices (SQUIDs) that work in liquid helium, have been too expensive for widespread use. This paper presents a less expensive liver susceptometer that works at room temperature. This system uses oscillating magnetic fields, which are produced and detected by

William F. Avrin; Sankaran Kumar

2007-01-01

426

A Fiber-Bragg-Grating-Based Sensor for Simultaneous AC Current and Temperature Measurement  

Microsoft Academic Search

In this paper, a sensor that is capable of measuring both ac current and temperature using a single fiber Bragg grating (FBG) is described. The device consists of a magnetically biased magnetostrictive alloy bonded to an FBG. The magnetic field generated by the current in a specially designed coil produces internal strains in the magnetostrictive alloy which can be detected

Deborah Reilly; Andrew J. Willshire; Grzegorz Fusiek; Pawel Niewczas; James R. McDonald

2006-01-01

427

A fibre Bragg grating based sensor for simultaneous AC current and temperature measurement  

Microsoft Academic Search

In this paper, we describe a sensor capable of measuring both AC current and temperature using a single fibre Bragg grating (FBG). The device consists of a magnetically biased magnetostrictive alloy bonded to an FBG. The magnetic field generated by the current in a specially designed coil produces internal strains in the magnetostrictive alloy which can be detected by the

Deborah Reilly; Andrew J. Willshire; Grzegorz Fusiek; Pawel Niewczas; James R. McDonald

2004-01-01

428

Fiberoptic Probe for Measuring High Frequency Temperature Fluctuations in Combustion Gases.  

National Technical Information Service (NTIS)

A new fiberoptic probe for measuring high frequency gas-temperature fluctuations is described. The fiberoptic probe is an optical pyrometer in which the thermal radiation is transmitted through an optical fiber. The key element in the device is a high tem...

R. R. Dils D. A. Tichenor

1984-01-01

429

A single chip broadband noise source for noise measurements at cryogenic temperatures  

Microsoft Academic Search

This paper presents the design and performance of a single chip broadband noise source dedicated for on-chip measurements in a cryogenic environment. The noise source is used to generate the two input noise powers Pc and Ph which are required by the commonly used Y-factor method. High accuracy in temperature control and impedance presented to the device under test is

D. Bruch; F. Schafer; M. Seelmann-Eggebert; B. Aja; I. Kallfass; A. Leuther; M. Schlechtweg; O. Ambacher

2011-01-01

430

Temperature Measurements Reveal Accretion Of Ice On Airfoils  

NASA Technical Reports Server (NTRS)

Method of detecting accretion of ice on airfoil based on measurement of difference between temperatures at icing and nonicing locations on airfoil. Release of latent heat of fusion gives rise to characteristic gradient of temperature. Temperatures and difference between them measured by use of contact sensors or remote sensor. Measurements used to trigger alarms and/or deicing equipment.

Hansman, Robert J., Jr.; Dershowitz, Adam Lee

1995-01-01

431

Soil moisture inferences from thermal infrared measurements of vegetation temperatures  

NASA Technical Reports Server (NTRS)

Thermal infrared measurements of wheat (Triticum durum) canopy temperatures were used in a crop water stress index to infer root zone soil moisture. Results indicated that one time plant temperature measurement cannot produce precise estimates of root zone soil moisture due to complicating plant factors. Plant temperature measurements do yield useful qualitative information concerning soil moisture and plant condition.

Jackson, R. D. (principal investigator)

1981-01-01

432

Parallel DAF measurement device (PDMD) for non-intrusive whitening of speech  

Microsoft Academic Search

A novel linear whitening measurement device is presented in this paper that allows optimal echo path modelling using real time least mean square (LMS) system identification techniques. The device provides improved and accurate characterisation of the far-end echo path using only half-duplex speech during conversational calls. The in-service non-intrusive parallel digital adaptive filter measurement device (PDMD) is based on a

Wai Pang Ng; J. M. H. Elmirghani; S. Broom

2001-01-01

433

Operation and maintenance of a deep-well water-level measurement device, the ''Iron Horse''  

Microsoft Academic Search

The deep-well investigative device, commonly called the Iron Horse, has been used primarily for measuring deep water levels in boreholes and wells. The device has proven useful in measurements during hydraulic testing of wells with water levels as deep as 2,600 feet (792.5 metres). The device may also be used for obtaining water samples, sounding depths, and determining vertical fluid

J. E. Jr. Weir; J. W. Nelson

1976-01-01

434

MELIFT - A new device for accurate measurements in a snow rich environment  

NASA Astrophysics Data System (ADS)

A deep snow pack, remote locations, no external power supply and very low temperatures are often the main ingredients when it comes to the deployment of meteorological stations in mountainous terrain. The accurate position of the sensor related to the snow surface is normally not known. A new device called METLIFT overcomes the problems. WMO recommends a height between 1.2 m and 2 m above ground level for the measurement of air temperature and humidity. The height above ground level is specified to take care of the possible strong vertical temperature and humidity gradients at the lowest layers in the atmosphere. Especially in snow rich and remote locations it may be hardly possible to follow this advice. Therefore most of the meteorological stations in mountainous terrain are situated at mountain tops where strong winds will blow off the snow or in valleys where a daily inspection of the sensors is possible. In other unpopulated mountainous areas, e.g. basins, plateaus, the distance of the sensor to the snow surface is not known or the sensor will be snow-covered. A new device was developed to guarantee the sensor height above surface within the WMO limits in harsh and remote environments. An ultrasonic snow height sensor measures the distance to the snow surface. If it exceeds certain limits due to snow accumulation or snow melt the lift adapts its height accordingly. The prototype of METLIFT has been installed in Lower Austria at an altitude of 1000m. The lift is 6 m high and can pull out for another 4 m. Sensor arms are mounted every meter to allow the connection of additional sensors or to measure a profile of a certain parameter of the lowest 5 m above surface. Sensors can be added easily since cable wiring is provided to each sensor arm. Horizontal winds are measured at 7 m height above surface. METLIFT is independent of external power supply. Three lead gel accumulators recharged by three solar panels provide the energy necessary for the sensors, the data loggers, the data transmission components and for the electromotor to lift the system. METLIFT is energy optimised to keep the energy consumption at low levels. The components of the lift device consist of a 12V electromotor with a worm gear with a transmission rate of 2856:1. This means that the lift moves extremely slow. The data logger can be programmed via the GSM connection from remote locations, the data flow is also conducted via this connection. First results of the winter campaign 2011/2012 will be presented at the conference.

Dorninger, M.

2012-04-01

435

Thermoelectric Behavior of Sb and Al-Doped n Type Mg 2 Si Device Under Large Temperature Differences  

Microsoft Academic Search

The thermoelectric (TE) characteristics of Sb- and Al-doped n-type Mg2Si elemental devices fabricated using material produced from molten commercial doped polycrystalline Mg2Si were examined. The TE devices were prepared using a plasma-activated sintering (PAS) technique. To complete the devices,\\u000a Ni electrodes were fabricated on each end of them during the sintering process. To realize durable devices for large temperature\\u000a differences,

Tatsuya Sakamoto; Tsutomu Iida; Shota Kurosaki; Kenji Yano; Hirohisa Taguchi; Keishi Nishio; Yoshifumi Takanashi

2011-01-01

436

A Low-Cost Thermistor Device for Measurements of Metabolic Heat in Yeast Cells in Suspension.  

ERIC Educational Resources Information Center

Provides illustrated directions for the construction and use of a low-cost thermistor device. Attached to a servo-type millivolt chart recorder, the device will record minute temperature changes and will simulate data obtained from an oxygen polarograph. Includes results of experiments with baker's yeast. (Author/CS)

Keeling, Richard P.

1980-01-01

437

2-D simulation and analysis of temperature effects on electrical parameters degradation of power RF LDMOS device  

Microsoft Academic Search

This paper presents a synthesis of temperature effects on power RF Laterally Diffused (LD) MOS performances, which can modify and degrade transistor physical and electrical behaviour. In this work, the temperature influence on device electrical characteristics is discussed with regard to physical limits for device operation. A developed 2-D structure was implemented and simulated using the physical simulator Silvaco-Atlas to

M. A. Belad; K. Ketata; M. Gares; J. Marcon; K. Mourgues; M. Masmoudi

2006-01-01

438

Devices for Measuring Internal Strains in Hardened Concrete.  

National Technical Information Service (NTIS)

The results obtained with two McCarthy type electric-resistance strain gages embedded in concrete are described. A study of the technical literature dealing with embeddable devices shows that the following four types are worthy of further investigation: t...

W. R. Lorman

1964-01-01

439

Measurement of Alpha Particle Radioactivtiy in IC Device Packages  

Microsoft Academic Search

Alpha particle radioactivity in package materials has been shown to cause soft errors in semiconductor devices. The particles are emitted by uranium and thorium decay sequence radioactive isotopes present as trace impurities in the raw materials used to make the package component parts. Chemical and radiation analys s techniques were correlated to alpha particle fluxes, which range in value from

E. S. Meieran; P. R. Engel; T. C. May

1979-01-01

440

Semiconductor Measurement Technology: A Laser Scanner for Semiconductor Devices.  

National Technical Information Service (NTIS)

The report is a construction guide and operators manual for a laser scanner built for semiconductor device studies. A very brief discussion of the theory of operation of the scanner is given. The scanner's operation from a systems point of view is describ...

D. E. Sawyer D. W. Berning

1977-01-01

441

Analysis of a heat transfer device for measuring film coefficients  

NASA Technical Reports Server (NTRS)

A heat transfer device consisting of a heated rotating cylinder in a bath was analyzed for its effectiveness to determine heat transfer coefficient of fluids. A time dependent analysis shows that the performance is insensitive to the value of heat transfer coefficient with the given rig configuration.

Medrow, R. A.; Johnson, R. L.; Loomis, W. R.; Wedeven, L. D.

1975-01-01

442

Bucket Wheel Assembly for a Flow Measuring Device.  

National Technical Information Service (NTIS)

In the scientific study of streams and rivers, it is desirable to take accurate readings of the various hydrological characteristics of the stream, particularly with regard to water flow. Many devices have been constructed in the past which are able throu...

J. C. Futrell

1987-01-01

443

Complete Bell state measurement with a solid state device  

Microsoft Academic Search

A solid state device, composed of two photon absorption crystals, rotators, and retarders, is proposed to discriminate all the four Bell states. Crystal symmetry and interference allow the absorption of a particular Bell state. The rotators and the retarders transform the other states to the state that can be detected.

Akihisa Tomita

2001-01-01

444

Surface temperature measurements in rolling and sliding EHD contacts  

NASA Technical Reports Server (NTRS)

In this study, moving surface temperature measurements in rolling and sliding EHD point contacts were made using an available infrared technique. Film thickness and traction have also been measured. Slide-to-roll ratios of -2 to +2 have been studied. By using a different kinematic configuration, stationary surface temperatures have also been measured. It has been shown that, while surface temperature rises in the low slip region are relatively small, stationary surface temperatures are significantly higher than the moving surface temperatures. Flash temperature theory has been extended to cover the combined rolling and sliding conditions. Correlation between the predicted and the measured values has also been performed.

Nagaraj, H.