Blind system identification of two-thermocouple sensor based on cross-relation method

Science.gov (United States)

Li, Yanfeng; Zhang, Zhijie; Hao, Xiaojian

2018-03-01

In dynamic temperature measurement, the dynamic characteristics of the sensor affect the accuracy of the measurement results. Thermocouples are widely used for temperature measurement in harsh conditions due to their low cost, robustness, and reliability, but because of the presence of the thermal inertia, there is a dynamic error in the dynamic temperature measurement. In order to eliminate the dynamic error, two-thermocouple sensor was used to measure dynamic gas temperature in constant velocity flow environments in this paper. Blind system identification of two-thermocouple sensor based on a cross-relation method was carried out. Particle swarm optimization algorithm was used to estimate time constants of two thermocouples and compared with the grid based search method. The method was validated on the experimental equipment built by using high temperature furnace, and the input dynamic temperature was reconstructed by using the output data of the thermocouple with small time constant.

Attaching Thermocouples by Peening or Crimping

Science.gov (United States)

Murtland, Kevin; Cox, Robert; Immer, Christopher

2006-01-01

Two simple, effective techniques for attaching thermocouples to metal substrates have been devised for high-temperature applications in which attachment by such conventional means as welding, screws, epoxy, or tape would not be effective. The techniques have been used successfully to attach 0.005- in. (0.127-mm)-diameter type-S thermocouples to substrates of niobium alloy C-103 and stainless steel 416 for measuring temperatures up to 2,600 F (1,427 C). The techniques are equally applicable to other thermocouple and substrate materials. In the first technique, illustrated in the upper part of the figure, a hole slightly wider than twice the diameter of one thermocouple wire is drilled in the substrate. The thermocouple is placed in the hole, then the edge of the hole is peened in one or more places by use of a punch (see figure). The deformed material at the edge secures the thermocouple in the hole. In the second technique a hole is drilled as in the first technique, then an annular relief area is machined around the hole, resulting in structure reminiscent of a volcano in a crater. The thermocouple is placed in the hole as in the first technique, then the "volcano" material is either peened by use of a punch or crimped by use of sidecutters to secure the thermocouple in place. This second technique is preferable for very thin thermocouples [wire diameter .0.005 in. (.0.127 mm)] because standard peening poses a greater risk of clipping one or both of the thermocouple wires. These techniques offer the following advantages over prior thermocouple-attachment techniques: . Because these techniques involve drilling of very small holes, they are minimally invasive . an important advantage in that, to a first approximation, the thermal properties of surrounding areas are not appreciably affected. . These techniques do not involve introduction of any material, other than the substrate and thermocouple materials, that could cause contamination, could decompose, or oxidize

Travelling gradient thermocouple calibration

International Nuclear Information System (INIS)

Broomfield, G.H.

1975-01-01

A short discussion of the origins of the thermocouple EMF is used to re-introduce the idea that the Peltier and Thompson effects are indistinguishable from one another. Thermocouples may be viewed as devices which generate an EMF at junctions or as integrators of EMF's developed in thermal gradients. The thermal gradient view is considered the more appropriate, because of its better accord with theory and behaviour, the correct approach to calibration, and investigation of service effects is immediately obvious. Inhomogeneities arise in thermocouples during manufacture and in service. The results of travelling gradient measurements are used to show that such effects are revealed with a resolution which depends on the length of the gradient although they may be masked during simple immersion calibration. Proposed tests on thermocouples irradiated in a nuclear reactor are discussed

Reply to ''Comment on 'Thermocouple temperature measurements in shock-compressed solids' ''

International Nuclear Information System (INIS)

Bloomquist, D.D.; Sheffield, S.A.

1982-01-01

We disagree with the interpretation offered in the above comment. The suggestion was made that the anomalously fast response of thin-foil thermocouples reported previously is the result of strain dependence of the thermocouple response and not shock enhanced thermal equilibration. Although the emplacement geometry has a profound effect on the response of embedded thin-foil temperature gauges as noted in the above comment, the evidence presented, along with recent results discussed in this reply, do not support the conclusions presented in the above comment

Thermocouple modeling

International Nuclear Information System (INIS)

Fryer, M.O.

1984-01-01

The temperature measurements provided by thermocouples (TCs) are important for the operation of pressurized water reactors. During severe inadequate core cooling incidents, extreme temperatures may cause type K thermocouples (TCs) used for core exit temperature monitoring to perform poorly. A model of TC electrical behavior has been developed to determine how TCs react under extreme temperatures. The model predicts the voltage output of the TC and its impedance. A series of experiments were conducted on a length of type K thermocouple to validate the model. Impedance was measured at several temperatures between 22 0 C and 1100 0 C and at frequencies between dc and 10 MHz. The model was able to accurately predict impedance over this wide range of conditions. The average percentage difference between experimental data and the model was less than 6.5%. Experimental accuracy was +-2.5%. There is a sriking difference between impedance versus frequency plots at 300 0 C and at higher temperatures. This may be useful in validating TC data during accident conditions

Fabrication and use of zircaloy/tantalum-sheathed cladding thermocouples and molybdenum/rhenium-sheathed fuel centerline thermocouples

International Nuclear Information System (INIS)

Wilkins, S.C.; Sepold, L.K.

1985-01-01

The thermocouples described in this report are zircaloy/tantalum-sheathed and molybdenum/rhenium alloy-sheathed instruments intended for fuel rod cladding and fuel centerline temperature measurements, respectively. Both types incorporate beryllium oxide insulation and tungsten/rhenium alloy thermoelements. These thermocouples, operated at temperatures of 2000 0 C and above, were developed for use in the internationally sponsored Severe Fuel Damage test series in the Power Burst Facility. The fabrication steps for both thermocouple types are described in detail. A laser-welding attachment technique for the cladding-type thermocouple is presented, and experience with alternate materials for cladding and fuel therocouples is discussed

Adhesive-Bonded Tab Attaches Thermocouples to Titanium

Science.gov (United States)

Cook, C. F.

1982-01-01

Mechanical strength of titanium-alloy structures that support thermocouples is preserved by first spotwelding thermocouples to titanium tabs and then attaching tabs to titanium with a thermosetting adhesive. In contrast to spot welding, a technique previously used for thermocouples, fatigue strength of the titanium is unaffected by adhesive bonding. Technique is also gentler than soldering or attaching thermocouples with a tap screw.

PWR thermocouple mechanical sealing structure

International Nuclear Information System (INIS)

Shen Qiuping; He Youguang

1991-08-01

The PWR in-core temperature detection device, which is one of measures to insure reactor safety operation, is to monitor and diagnose reactor thermal power output and in-core power distribution. The temperature detection device system uses thermocouples as measuring elements with stainless steel protecting sleeves. The thermocouple has a limited service time and should be replaced after its service time has reached. A new sealing device for the thermocouples of reactor in-core temperature detection system has been developed to facilitate replacement. The structure is complete tight under high temperature and pressure without any leakage and seepage, and easy to be assembled or disassembled in radioactive environment. The device is designed to make it possible to replace the thermocouple one by one if necessary. This is a new, simple and practical structure

Low Drift Type N Thermocouples for Nuclear Applications

International Nuclear Information System (INIS)

Scervini, M.; Rae, C.

2013-06-01

Thermocouples are the most commonly used sensors for temperature measurement in nuclear reactors. They are crucial for the control of current nuclear reactors and for the development of GEN IV reactors. In nuclear applications thermocouples are strongly affected by intense neutron fluxes. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition and, as a consequence, a time dependent drift of the thermocouple signal. Thermocouple drift can be very significant for in-pile temperature measurements and may render the temperature sensors unreliable after exposure to nuclear radiation for relatively short times compared to the life required for temperature sensors in nuclear applications. Previous experiences with type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly type N thermocouples are expected to be only slightly affected by neutron fluxes. Currently the use of Nickel based thermocouples is limited to temperatures lower than 1000 deg. C due to drift related to phenomena other than nuclear irradiation. In this work, undertaken as part of the European project METROFISSION, the drift of type N thermocouples has been investigated in the temperature range 600-1300 deg. C. The approach of this study is based on the attempt to separate the contributions of each thermo-element to drift. In order to identify the dominant thermo-element for drift, the contributions of both positive (NP) and negative (NN) thermo-elements to the total drift of 3.2 mm diameter MIMS thermocouples have been measured in each drift test using a pure Pt thermo-element as a reference. Conventional Inconel-600 sheathed type N thermocouples have been compared with type N thermocouples sheathed in a new alloy. At temperatures higher than 1000 deg. C conventional Inconel600 sheathed type N thermocouples can experience a

Noncontacting Measurement With a Thermocouple

Science.gov (United States)

Weatherill, W. T.; Schoreder, C. J.; Freitag, H. J.

1986-01-01

Tentlike covering brings thermocouple to within few degrees of surface temperature. Technique originally developed for measuring surface temperature of quartz fabric under radiant heating requires no direct contact with heated surface. Technique particularly useful when measuring surface temperatures of materials damaged if thermocouple or other temperature sensor attached.

LOFT small break test thermocouple installation

International Nuclear Information System (INIS)

Fors, R.M.

1980-01-01

The subject thermocouple design has been analyzed for maximum expected hydraulic loading and found to be adequate. The natural frequency of the thermocouple was found to be between the vortex shedding frequencies for the gas and liquid phase so that a tendency for resonance will exist. However, since the thermocouple support will have a restricted displacement, stresses found are below the endurance limit and, thus, are acceptable in respect to fatigue life as well as primary stress due to pressure loading

Transmutation of Thermocouples in Thermal and Fast Nuclear Reactors

International Nuclear Information System (INIS)

Scervini, M.; Rae, C.; Lindley, B.

2013-06-01

Thermocouples are the most commonly used sensors for temperature measurement in nuclear reactors. Their role is fundamental for the control of current nuclear reactors and for the development of the nuclear technology needed for the implementation of GEN IV nuclear reactors. When used for in-core measurements thermocouples are strongly affected not only by high temperatures, but also by intense neutron fluxes. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition in the thermoelements and, as a consequence, a time dependent drift in the thermocouple signal. Thermocouple drift can be very significant for in-pile temperature measurements and may render the temperature sensors unreliable after exposure to nuclear radiation for relatively short times compared to the life required for temperature sensors in nuclear applications. In this work, undertaken as part of the European project METROFISSION, the change in composition occurring in irradiated thermocouples has been calculated using the software ORIGEN 2.2. Several thermocouples have been considered, including Nickel based thermocouples (type K and type N), Tungsten based thermocouples (W-5%Re vs W-26%Re and W- 3%Re vs W-25%Re), Platinum based thermocouples (type S and Platinum vs Palladium) and Molybdenum vs Niobium thermocouples. The transmutation induced by both thermal flux and fast flux has been calculated. Thermocouples undergo more pronounced transmutation in thermal fluxes rather than in fast fluxes, as the neutron cross section of an element is higher for thermal energies. Nickel based thermocouples have a minimal change in composition, while Platinum based and Tungsten based thermocouples experience a very significant transmutation. The use of coatings deposited on the sheath of a thermocouple has been considered as a mean to reduce the neutron flux the thermoelements inside the thermocouple sheath

Spatial filtring and thermocouple spatial filter

International Nuclear Information System (INIS)

Han Bing; Tong Yunxian

1989-12-01

The design and study on thermocouple spatial filter have been conducted for the flow measurement of integrated reactor coolant. The fundamental principle of spatial filtring, mathematical descriptions and analyses of thermocouple spatial filter are given

A novel method for in-situ estimation of time constant for core temperature monitoring thermocouples of operating reactors

International Nuclear Information System (INIS)

Sylvia, J.I.; Chandar, S. Clement Ravi; Velusamy, K.

2014-01-01

Highlights: • Core temperature sensor was mathematically modeled. • Ramp signal generated during reactor operating condition is used. • Procedure and methodology has been demonstrated by applying it to FBTR. • Same technique will be implemented for all fast reactors. - Abstract: Core temperature monitoring system is an important component of reactor protection system in the current generation fast reactors. In this system, multiple thermocouples are housed inside a thermowell of fuel subassemblies. Response time of the thermocouple assembly forms an important input for safety analysis of fast reactor and hence frequent calibration/time constant estimation is essential. In fast reactors the central fuel subassembly is provided with bare fast response thermocouples to detect under cooling events in reactor and take proper safety action. On the other hand, thermocouples in thermowell are mainly used for blockage detection in individual fuel subassemblies. The time constant of thermocouples in thermowell can drift due to creep, vibration and thermal fatigue of the thermowell assembly. A novel method for in-situ estimation of time constant is proposed. This method uses the Safety Control Rod Accelerated Mechanism (SCRAM) or lowering of control Rod (LOR) signals of the reactor along with response of the central subassembly thermocouples as reference data. Validation of the procedure has been demonstrated by applying it to FBTR

Embedded cladding surface thermocouples on Zircaloy-sheathed heater rods

International Nuclear Information System (INIS)

Wilkins, S.C.

1977-06-01

Titanium-sheathed Type K thermocouples embedded in the cladding wall of zircaloy-sheathed heater rods are described. These thermocouples constitute part of a program intended to characterize the uncertainty of measurements made by surface-mounted cladding thermocouples on nuclear fuel rods. Fabrication and installation detail, and laboratory testing of sample thermocouple installations are included

Base metal thermocouples drift rate dependence from thermoelement diameter

Science.gov (United States)

Pavlasek, P.; Duris, S.; Palencar, R.

2015-02-01

Temperature measurements are one of the key factors in many industrial applications that directly affect the quality, effectiveness and safety of manufacturing processes. In many industrial applications these temperature measurements are realized by thermocouples. Accuracy of thermocouples directly affects the quality of the final product of manufacturing and their durability determines the safety margins required. One of the significant effects that affect the precision of the thermocouples is short and long term stability of their voltage output. This stability issue occurs in every type of thermocouples and is caused by multiple factors. In general these factors affect the Seebeck coefficient which is a material constant, which determines the level of generated voltage when exposed to a temperature gradient. Changes of this constant result in the change of the thermocouples voltage output thus indicated temperature which can result in production quality issues, safety and health hazards. These alternations can be caused by physical and chemical changes within the thermocouple lead material. Modification of this material constant can be of temporary nature or permanent. This paper concentrates on the permanent, or irreversible changes of the Seebeck coefficient that occur in commonly used swaged MIMS Type N thermocouples. These permanent changes can be seen as systematic change of the EMF of the thermocouple when it is exposed to a high temperature over a period of time. This change of EMF by time is commonly known as the drift of the thermocouple. This work deals with the time instability of thermocouples EMF at temperatures above 1200 °C. Instability of the output voltage was taken into relation with the lead diameter of the tested thermocouples. This paper concentrates in detail on the change of voltage output of thermocouples of different diameters which were tested at high temperatures for the overall period of more than 210 hours. The gather data from this

Base metal thermocouples drift rate dependence from thermoelement diameter

International Nuclear Information System (INIS)

Pavlasek, P; Duris, S; Palencar, R

2015-01-01

Temperature measurements are one of the key factors in many industrial applications that directly affect the quality, effectiveness and safety of manufacturing processes. In many industrial applications these temperature measurements are realized by thermocouples. Accuracy of thermocouples directly affects the quality of the final product of manufacturing and their durability determines the safety margins required. One of the significant effects that affect the precision of the thermocouples is short and long term stability of their voltage output. This stability issue occurs in every type of thermocouples and is caused by multiple factors. In general these factors affect the Seebeck coefficient which is a material constant, which determines the level of generated voltage when exposed to a temperature gradient. Changes of this constant result in the change of the thermocouples voltage output thus indicated temperature which can result in production quality issues, safety and health hazards. These alternations can be caused by physical and chemical changes within the thermocouple lead material. Modification of this material constant can be of temporary nature or permanent. This paper concentrates on the permanent, or irreversible changes of the Seebeck coefficient that occur in commonly used swaged MIMS Type N thermocouples. These permanent changes can be seen as systematic change of the EMF of the thermocouple when it is exposed to a high temperature over a period of time. This change of EMF by time is commonly known as the drift of the thermocouple. This work deals with the time instability of thermocouples EMF at temperatures above 1200 °C. Instability of the output voltage was taken into relation with the lead diameter of the tested thermocouples. This paper concentrates in detail on the change of voltage output of thermocouples of different diameters which were tested at high temperatures for the overall period of more than 210 hours. The gather data from this

Thermocouple evaluation model and evaluation of chromel--alumel thermocouples for High-Temperature Gas-Cooled Reactor applications

International Nuclear Information System (INIS)

Washburn, B.W.

1977-03-01

Factors affecting the performance and reliability of thermocouples for temperature measurements in High-Temperature Gas-Cooled Reactors are investigated. A model of an inhomogeneous thermocouple, associated experimental technique, and a method of predicting measurement errors are described. Error drifts for Type K materials are predicted and compared with published stability measurements. 60 references

Thermocouple pressure bushing in suspension rod

International Nuclear Information System (INIS)

Pasek, J.; Ondreicka, K.

1975-01-01

The seal is described of jacket thermocouples located in the pressure reducer in the fuel element suspension rod. The thermocouples are sealed in the pressure reducer with a silicon sealing compound. The sealing compound is compressed between the two reducers with a Bellevile spring and a pressure washer secured in position with a spring. The axial pressure of the inner parts of the reducer on the compound is adjustable by means of a thrust screw. The tightness and alignment of the thermocouples in the pressure reducer is achieved by tightening the thrust screw to the stop of the top reducer and the subsequent setting of the sealing compound. (J.B.)

Self-adapted thermocouple-diagnostic complex

International Nuclear Information System (INIS)

Alekseev, S.V.; Grankovskij, K.Eh.; Olejnikov, P.P.; Prijmak, S.V.; Shikalov, V.F.

2003-01-01

A self-adapted thermocouple-diagnostic complex (STDC) for obtaining the reliable data on the coolant temperature in the reactors of NPP is described. The STDC in based on the thermal pulse monitoring of a thermocouple in the measuring channel of a reactor. Measurement method and STDC composition are substantiated. It is shown that introduction of the developed STDC ensures realization of precise and reliable temperature monitoring in the reactors of all types [ru

A comprehensive survey of thermoelectric homogeneity of commonly used thermocouple types

Science.gov (United States)

Machin, Jonathan; Tucker, Declan; Pearce, Jonathan V.

2018-06-01

Thermocouples are widely used as temperature sensors in industry. The electromotive force generated by a thermocouple is produced in a temperature gradient and not at the thermocouple tip. This means that the thermoelectric inhomogeneity represents one of the most important contributions to the overall measurement uncertainty associated with thermocouples. To characterise this effect, and to provide some general recommendations concerning the magnitude of this contribution to use when formulating uncertainty analyses, a comprehensive literature survey has been performed. Significant information was found for Types K, N, R, S, B, Pt/Pd, Au/Pt and various other Pt/Rh thermocouples. In the case of Type K and N thermocouples, the survey has been augmented by a substantial amount of data based on calibrations of mineral-insulated, metal-sheathed thermocouple cable reels from thermocouple manufacturers. Some general conclusions are drawn and outline recommendations given concerning typical values for the uncertainty arising from thermoelectric inhomogeneity for the most widely used thermocouple types in the as-new state. It is stressed that these recommendations should only be heeded when individual homogeneity measurements are not possible. It is also stressed that the homogeneity can deteriorate rapidly during use, particularly for base metal thermocouples.

A thermocouple thermometry system for ultrasound hyperthermia

International Nuclear Information System (INIS)

Ozarka, M.; Gharakhani, A.; Magin, R.; Cain, C.

1984-01-01

A thermometry system designed to be used in the treatment of cancer by ultrasound hyperthermia is described. The system monitors tumor temperatures using 16 type T (copper-constantan) thermocouples and is controlled by a 12 MHz Intel 8031 microcomputer. An analog circuit board contains the thermocouple amplifiers, an analog multiplexer, scaling circuitry, and an analog to digital converter. A digital board contains the Intel 8031, program memory, data memory, as well as circuitry for control and data communications. Communication with the hyperthermia system control computer is serially by RS-232 with selectable baud rate. Since the thermocouple amplifiers may have slight differences in gain and offset, a calibrated offset is added to a lookup table value to obtain the proper display temperature to within +- 0.1 0 C. The calibration routine, implemented in software, loads a nonvolatile random access memory chip with the proper offset values based on the outputs of each thermocouple channel at known temperatures which bracket a range of interest

Estimation of radiation losses from sheathed thermocouples

International Nuclear Information System (INIS)

Roberts, I.L.; Coney, J.E.R.; Gibbs, B.M.

2011-01-01

Thermocouples are often used for temperature measurements in heat exchangers. However if the radiation losses from a thermocouple in a high temperature gas flow to colder surroundings are ignored significant errors can occur. Even at moderate temperature differences, these can be significant. Prediction of radiation losses from theory can be problematic, especially in situations where there are large variations in the measured temperatures as the emissivity and radiative heat transfer coefficient of the thermocouple are not constant. The following approach combines experimental results with established empirical relationships to estimate losses due to radiation in an annular heat exchanger at temperatures up to 950 o C. - Highlights: → Sheathed thermocouples are often used to measure temperatures in heat exchangers. → Errors are introduced if radiation losses are ignored. → Radiation losses are environment specific and may be significant. → Experimental and theoretical methods are used to estimate losses. → Hot side maximum temperature 950 o C.

Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

Directory of Open Access Journals (Sweden)

Otto J. Gregory

2013-11-01

Full Text Available Temperatures of hot section components in today’s gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today’s engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire thermocouples.

Technological improvements to high temperature thermocouples for nuclear reactor applications

International Nuclear Information System (INIS)

Schley, R.; Leveque, J.P.

1980-07-01

The specific operating conditions of thermocouples in nuclear reactors have provided an incentive for further advances in high temperature thermocouple applications and performance. This work covers the manufacture and improvement of existing alloys, the technology of clad thermocouples, calibration drift during heat treatment, resistance to thermal shock and the compatibility of insulating materials with thermo-electric alloys. The results lead to specifying improved operating conditions for thermocouples in nuclear reactor media (pressurized water, sodium, uranium oxide) [fr

Thin film platinum–palladium thermocouples for gas turbine engine applications

Energy Technology Data Exchange (ETDEWEB)

Tougas, Ian M.; Gregory, Otto J., E-mail: gregory@egr.uri.edu

2013-07-31

Thin film platinum:palladium thermocouples were fabricated on alumina and mullite surfaces using radio frequency sputtering and characterized after high temperature exposure to oxidizing environments. The thermoelectric output, hysteresis, and drift of these sensors were measured at temperatures up to 1100 °C. Auger electron spectroscopy was used to follow the extent of oxidation in each thermocouple leg and interdiffusion at the metallurgical junction. Minimal oxidation of the platinum and palladium thermoelements was observed after high temperature exposure, but considerable dewetting and faceting of the films were observed in scanning electron microscopy. An Arrhenius temperature dependence on the drift rate was observed and later attributed to microstructural changes during thermal cycling. The thin film thermocouples, however, did exhibit excellent stability at 1000 °C with drift rates comparable to commercial type-K wire thermocouples. Based on these results, platinum:palladium thin film thermocouples have considerable potential for use in the hot sections of gas turbine engines. - Highlights: • Stable thin film platinum:palladium thermocouples for gas turbine engines • Little oxidation but significant microstructural changes from thermal cycling • Minimal hysteresis during repeated thermal cycling • Drift comparable to commercial wire thermocouples.

A method to eliminate the effect of radiation on thermocouple performance

International Nuclear Information System (INIS)

Ali, Fawaz; Lu Lixuan

2007-01-01

In-core temperature measurements are pivotal in maintaining nuclear reactors in a safe state of operation. Thermocouples serve as the liaison in ensuring this safe state. The realization of the thermocouple's full potential is hindered by the fact that thermocouples cannot be situated in areas with high radiation fields. Radiation has the potential of generating voltages in the thermocouple wires, hence producing an error in the temperature transmitter output. In this paper, a mathematical model is developed to quantify the effect that radiation from the Canada Deuterium Uranium (CANDU) Nuclear Power Plants (NPPs) has on the thermocouple temperature reading. Subsequently, a method to offset the effect of radiation on the thermocouple is proposed. Simulation is performed to verify the effectiveness of the proposed system

Summary of Thermocouple Performance During Advanced Gas Reactor Fuel Irradiation Experiments in the Advanced Test Reactor and Out-of-Pile Thermocouple Testing in Support of Such Experiments

Energy Technology Data Exchange (ETDEWEB)

A. J. Palmer; DC Haggard; J. W. Herter; M. Scervini; W. D. Swank; D. L. Knudson; R. S. Cherry

2011-07-01

High temperature gas reactor experiments create unique challenges for thermocouple based temperature measurements. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition and, as a consequence, a time dependent drift of the thermocouple signal. This drift is particularly severe for high temperature platinum-rhodium thermocouples (Types S, R, and B); and tungsten-rhenium thermocouples (Types C and W). For lower temperature applications, previous experiences with type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly type N thermocouples are expected to be only slightly affected by neutron fluxes. Currently the use of these Nickel based thermocouples is limited when the temperature exceeds 1000°C due to drift related to phenomena other than nuclear irradiation. High rates of open-circuit failure are also typical. Over the past ten years, three long-term Advanced Gas Reactor (AGR) experiments have been conducted with measured temperatures ranging from 700oC – 1200oC. A variety of standard Type N and specialty thermocouple designs have been used in these experiments with mixed results. A brief summary of thermocouple performance in these experiments is provided. Most recently, out of pile testing has been conducted on a variety of Type N thermocouple designs at the following (nominal) temperatures and durations: 1150oC and 1200oC for 2000 hours at each temperature, followed by 200 hours at 1250oC, and 200 hours at 1300oC. The standard Type N design utilizes high purity crushed MgO insulation and an Inconel 600 sheath. Several variations on the standard Type N design were tested, including Haynes 214 alloy sheath, spinel (MgAl2O4) insulation instead of MgO, a customized sheath developed at the University of Cambridge, and finally a loose assembly thermocouple with hard fired alumina

Summary of thermocouple performance during advanced gas reactor fuel irradiation experiments in the advanced test reactor and out-of-pile thermocouple testing in support of such experiments

Energy Technology Data Exchange (ETDEWEB)

Palmer, A. J.; Haggard, DC; Herter, J. W.; Swank, W. D.; Knudson, D. L.; Cherry, R. S. [Idaho National Laboratory, P.O. Box 1625, MS 4112, Idaho Falls, ID, (United States); Scervini, M. [University of Cambridge, Department of Material Science and Metallurgy, 27 Charles Babbage Road, CB3 0FS, Cambridge, (United Kingdom)

2015-07-01

High temperature gas reactor experiments create unique challenges for thermocouple-based temperature measurements. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time-dependent change in composition and, as a consequence, a time-dependent drift of the thermocouple signal. This drift is particularly severe for high temperature platinum-rhodium thermocouples (Types S, R, and B) and tungsten-rhenium thermocouples (Type C). For lower temperature applications, previous experiences with Type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly, Type N thermocouples are expected to be only slightly affected by neutron fluence. Currently, the use of these nickel-based thermocouples is limited when the temperature exceeds 1000 deg. C due to drift related to phenomena other than nuclear irradiation. High rates of open-circuit failure are also typical. Over the past 10 years, three long-term Advanced Gas Reactor experiments have been conducted with measured temperatures ranging from 700 deg. C - 1200 deg. C. A variety of standard Type N and specialty thermocouple designs have been used in these experiments with mixed results. A brief summary of thermocouple performance in these experiments is provided. Most recently, out-of-pile testing has been conducted on a variety of Type N thermocouple designs at the following (nominal) temperatures and durations: 1150 deg. C and 1200 deg. C for 2,000 hours at each temperature, followed by 200 hours at 1250 deg. C and 200 hours at 1300 deg. C. The standard Type N design utilizes high purity, crushed MgO insulation and an Inconel 600 sheath. Several variations on the standard Type N design were tested, including a Haynes 214 alloy sheath, spinel (MgAl{sub 2}O{sub 4}) insulation instead of MgO, a customized sheath developed at the University of Cambridge, and finally a loose assembly

Thermocouple correlation transit time flowmeter tests at WCL

International Nuclear Information System (INIS)

Lassahn, G.D.

1976-11-01

Scoping tests indicate the feasibility for using transit time flowmeters with thermocouple sensors in steam-water steady state flow. Conclusive results were not obtained. More conclusive results are expected from tests to be conducted in the semiscale facility with a redesigned transit time thermocouple sensor

Zircaloy-sheathed element rods fitted with thermo-couples; Barre combustible a thermocouple gainee de zircaloy

Energy Technology Data Exchange (ETDEWEB)

Bernardy de Sigoyer, B; Jacques, F; Thome, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

In order to carry out thermal conductivity measurements on UO{sub 2} in conditions similar to those under which fuel rods are used, it was necessary to measure the temperature at the interior of a fuel element sheathed in zircaloy. The temperatures are taken with Thermocoax type thermocouples, that is to say fitted with a very thin sheath of stainless steel or Inconel. It is known also that fusion welding of zircaloy onto stainless steel is impossible and that high temperature welded joints are very difficult because of their aggressiveness. The technique used consists in brazing the thermocouples to relatively large stainless steel parts and then joining these plugs by electron bombardment welding to diffused stainless steel-zircaloy couplings. The properties of these diffused couplings and of the brazed joints were studied; the various stages in the fabrication of the containers are also described. (authors) [French] Pour des mesures de conductivite thermique de l'UO{sub 2} dans des conditions voisines du fonctionnement des barres combustibles, il s'agissait de mesurer la temperature a l'interieur d'un element combustible gaine de zircaloy. Les prises de temperature sont faites par thermocouples du type Thermocoax, c'est-a-dire pourvu d'une gaine tres mince en inox ou inconel. Par ailleurs on sait que le soudage par fusion du zircaloy sur l'inox est impossible et que les brasures a haute temperature sont difficiles car tres agressives. La technique utilisee consiste a braser les thermocouples sur des pieces en inox relativement massives et de rapporter par soudage au bombardement electronique ces bouchons sur des raccords diffuses zircaloy-inox. Les proprietes de ces raccords diffuses et celles de joints brases ont ete etudiees; on expose egalement les diverses etapes de fabrication des containers. (auteurs)

Relative humidity measurements with thermocouple psychrometer and capacitance sensors

International Nuclear Information System (INIS)

Mao, Naihsien.

1991-01-01

The relative humidity is one of the important hydrological parameters affecting waste package performance. Water potential of a system is defined as the amount of work required to reversibly and isothermally move an infinitesimal quantity of water from a pool of pure water to that system at the same elevation. The thermocouple psychrometer, which acts as a wet-dry bulb instrument based on the Peltier effect, is used to measure water potential. The thermocouple psychrometer works only for relative humidity greater than 94 percent. Other sensors must be used for drier conditions. Hence, the author also uses a Vaisala Humicap, which measures the capacitance change due to relative humidity change. The operation range of the Humicap (Model HMP 135Y) is from 0 to 100 percent relative humidity and up to 160C (320F) in temperature. A psychrometer has three thermocouple junctions. Two copper-constantan junctions serve as reference temperature junctions and the constantan-chromel junction is the sensing junction. Current is passed through the thermocouple causing cooling of the sensing junction by the Peltier effect. When the temperature of the junction is below the dew point, water will condense upon the junction from the air. The Peltier current is discontinued and the thermocouple output is recorded as the temperature of the thermocouple returns to ambient. The temperature changes rapidly toward the ambient temperature until it reaches the wet bulb depression temperature. At this point, evaporation of the water from the junction produces a cooling effect upon the junction that offsets the heat absorbed from the ambient surroundings. This continues until the water is depleted and the thermocouple temperature returns to the ambient temperature (Briscoe, 1984). The datalogger starts to take data roughly at the wet bulb depression temperature

Thermocouple design for measuring temperatures of small insects

Science.gov (United States)

A.A. Hanson; R.C. Venette

2013-01-01

Contact thermocouples often are used to measure surface body temperature changes of insects during cold exposure. However, small temperature changes of minute insects can be difficult to detect, particularly during the measurement of supercooling points. We developed two thermocouple designs, which use 0.51 mm diameter or 0.127 mm diameter copper-constantan wires, to...

Error analysis of thermocouple measurements in the Radiant Heat Facility

International Nuclear Information System (INIS)

Nakos, J.T.; Strait, B.G.

1980-12-01

The measurement most frequently made in the Radiant Heat Facility is temperature, and the transducer which is used almost exclusively is the thermocouple. Other methods, such as resistance thermometers and thermistors, are used but very rarely. Since a majority of the information gathered at Radiant Heat is from thermocouples, a reasonable measure of the quality of the measurements made at the facility is the accuracy of the thermocouple temperature data

Realization of Copper Melting Point for Thermocouple Calibrations

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Y. A. ABDELAZIZ

2011-08-01

Full Text Available Although the temperature stability and uncertainty of the freezing plateau is better than that of the melting plateau in most of the thermometry fixed points, but realization of melting plateaus are easier than that of freezing plateaus for metal fixed points. It will be convenient if the melting points can be used instead of the freezing points in calibration of standard noble metal thermocouples because of easier realization and longer plateau duration of melting plateaus. In this work a comparison between the melting and freezing points of copper (Cu was carried out using standard noble metal thermocouples. Platinum - platinum 10 % rhodium (type S, platinum – 30 % rhodium / platinum 6 % rhodium (type B and platinum - palladium (Pt/Pd thermocouples are used in this study. Uncertainty budget analysis of the melting points and freezing points is presented. The experimental results show that it is possible to replace the freezing point with the melting point of copper cell in the calibration of standard noble metal thermocouples in secondary-level laboratories if the optimal methods of realization of melting points are used.

Thermocouples used in emission systems of internal combustion engines; Thermoelemente fuer den Einsatz in Abgassystemen von Verbrennungsmotoren

Energy Technology Data Exchange (ETDEWEB)

Augustin, Silke; Froehlich, Thomas; Mammen, Helge [Technische Univ. Illmenau (Germany). Inst. fuer Prozessmess- und Sensortechnik; Ament, Christoph; Guether, Thomas [Technische Univ. Illmenau (Germany). Inst. fuer Automatisierungs- und Systemtechnik

2012-11-01

Thermocouples used in exhaust systems of combustion engines are exposed to high temperature gradients and temperature leaps ({Delta}T > 900 K), high flow speeds and pressure. When constructing these thermocouples, a compromise is needed between the resulting high demands on the mechanical-thermal stability, accuracy and the fast response time demanded by the servo-control of the motors. Additionally, a numerical correction of the measured signal may contribute to an improved sensor dynamics. (orig.)

Long duration performance of high temperature irradiation resistant thermocouples

International Nuclear Information System (INIS)

Rempe, J.; Knudson, D.; Condie, K.; Cole, J.; Wilkins, S.C.

2007-01-01

Many advanced nuclear reactor designs require new fuel, cladding, and structural materials. Data are needed to characterize the performance of these new materials in high temperature, radiation conditions. However, traditional methods for measuring temperature in-pile degrade at temperatures above 1100 C degrees. To address this instrumentation need, the Idaho National Laboratory (INL) developed and evaluated the performance of a high temperature irradiation-resistant thermocouple that contains alloys of molybdenum and niobium. To verify the performance of INL's recommended thermocouple design, a series of high temperature (from 1200 to 1800 C) long duration (up to six months) tests has been initiated. This paper summarizes results from the tests that have been completed. Data are presented from 4000 hour tests conducted at 1200 and 1400 C that demonstrate the stability of this thermocouple (less than 2% drift). In addition, post test metallographic examinations are discussed which confirm the compatibility of thermocouple materials throughout these long duration, high temperature tests. (authors)

Heat penetration and thermocouple location in home canning.

Science.gov (United States)

Etzel, Mark R; Willmore, Paola; Ingham, Barbara H

2015-01-01

We processed applesauce, tomato juice, and cranberries in pint jars in a boiling water canner to test thermal processing theories against home canning of high-acid foods. For each product, thermocouples were placed at various heights in the jar. Values for f h (heating), f cl (cooling), and F 82.2°C (lethality) were determined for each thermocouple location, and did not depend substantially on thermocouple location in accordance with heat transfer theory. There was a cold spot in the jar, but the cold spot during heating became the hot spot during cooling. During heating, the geometric center was the last to heat, and remained coldest the longest, but during coooling, it was also the last to cool, and remained hottest the longest. The net effect was that calculated lethality in home canning was not affected by thermocouple location. Most of the lethality during home canning occurred during air cooling, making cooling of home canned foods of great importance. Calculated lethality was far greater than the required 5-log reduction of spores in tomato juice and vegetative cells in cranberries, suggesting a wide margin of safety for approved home-canning processes for high-acid foods.

Temperature measurements by thermocouples

International Nuclear Information System (INIS)

Liermann, J.

1975-01-01

The measurement of a temperature (whatever the type of transducer used) raises three problems: the choice of transducer; where it should be placed; how it should be fixed and protected. These are the three main points examined, after a brief description of the most commonly used thermocouples [fr

Improvement in the technology of thermocouples for the detection of high temperatures with a view to using them in irradiation safety tests in reactor

International Nuclear Information System (INIS)

Schley, R.; Liermann, J.; Aujollet, J.M.; Wilkins, S.C.

1979-01-01

The safety tests carried out under the CABRI and PHEBUS programmes have made it possible to improve the technology of W/Re thermocouples and their reliability in particularly hard operating conditions. An element of response is provided to the problem of W/Re thermocouple drift under neutron flux by defining the new thermocouple Mo 5% Nb/Nb 10% Mo which, because of the low capture cross section of thermoelectric elements, gives one reason to hope for a less significant drift of these thermocouples under neutron flux than that found with W/Re thermocouples. Finally, determining the surface temperature of fuel element cladding with the Mo/Zircaloy thermocouple may prove worthwhile providing the temperatures do not exceed 1300 0 C and the electric insulator is aluminium oxide which up to 1300 0 C does not appear to react with thermoelectric wires [fr

Stability Studies of a New Design Au/Pt Thermocouple Without a Strain Relieving Coil

Science.gov (United States)

Jahan, Ferdouse; Ballico, Mark

2007-12-01

The performance of a simple, new design Au/Pt thermocouple developed by NMIA is assessed. This thermocouple is proposed as a more accurate replacement, over the temperature range from 0 to 1,000°C, for the commonly used Type R and S industrial transfer standards, in a robust form familiar to industrial calibration laboratories. Due to the significantly different thermal expansions of the Au and Pt thermoelements, reported designs of the Au/Pt thermocouple incorporate a strain-relieving coil or bridge at the thermocouple junction. As the strain relieving coil is mechanically delicate, these thermocouples are usually mounted in a protective quartz tube assembly, like a standard platinum resistance thermometer (SPRT). Although providing uncertainties at the mK level, they are more delicate than the commonly used Type R and S thermocouples. A new and simple design of the Au/Pt thermocouple was developed in which the differential thermal expansion between Au and Pt is accommodated in the thermocouple leads, facilitated by a special head design. The resulting thermocouple has the appearance and robustness of the traditional Type R and S thermocouples, while retaining stability better than 10 mK up to 961°C. Three thermocouples of this design were calibrated at fixed points and by comparison to SPRTs in a stirred salt bath. In order to assess possible impurity migration, strain effects, and mechanical robustness, sequences of heat treatment up to a total of 500 h together with over 50 thermal cycles from 900°C to ambient were performed. The effect of these treatments on the calibration was assessed, demonstrating the sensors to be robust and stable to better than 10 mK. The effects on the measured inhomogeneity of the thermocouple were assessed using the NMIA thermocouple scanning bath.

Contact Thermocouple Methodology and Evaluation for Temperature Measurement in the Laboratory

Science.gov (United States)

Brewer, Ethan J.; Pawlik, Ralph J.; Krause, David L.

2013-01-01

Laboratory testing of advanced aerospace components very often requires highly accurate temperature measurement and control devices, as well as methods to precisely analyze and predict the performance of such components. Analysis of test articles depends on accurate measurements of temperature across the specimen. Where possible, this task is accomplished using many thermocouples welded directly to the test specimen, which can produce results with great precision. However, it is known that thermocouple spot welds can initiate deleterious cracks in some materials, prohibiting the use of welded thermocouples. Such is the case for the nickel-based superalloy MarM-247, which is used in the high temperature, high pressure heater heads for the Advanced Stirling Converter component of the Advanced Stirling Radioisotope Generator space power system. To overcome this limitation, a method was developed that uses small diameter contact thermocouples to measure the temperature of heater head test articles with the same level of accuracy as welded thermocouples. This paper includes a brief introduction and a background describing the circumstances that compelled the development of the contact thermocouple measurement method. Next, the paper describes studies performed on contact thermocouple readings to determine the accuracy of results. It continues on to describe in detail the developed measurement method and the evaluation of results produced. A further study that evaluates the performance of different measurement output devices is also described. Finally, a brief conclusion and summary of results is provided.

Thermocouples for conditions of aggressive environments

International Nuclear Information System (INIS)

Blanc, J.Y.

1988-01-01

Two new kinds of thermocouples have been chosen for temperature measurements in the in-pile safety program for light water reactors performed in France. They must give fuel centerline or roc cladding temperatures and withstand steam oxidation between 1000 0 C and 1800 0 C or higher, under severe fuel damage conditions. We describe briefly both types, then we emphasize on improvements under way concerning the tungsten-rhenium legs, the hafnia insulation and the sheaths materials. Oxidation resistance is achieved mainly by silicides layers, but other possibilities are considered, such as iridium coatings. Some details of insulators manufacturing or sensor assembly are given, as well as other high temperature applications for these thermocouples

Characterization of a Method for Inverse Heat Conduction Using Real and Simulated Thermocouple Data

Science.gov (United States)

Pizzo, Michelle E.; Glass, David E.

2017-01-01

It is often impractical to instrument the external surface of high-speed vehicles due to the aerothermodynamic heating. Temperatures can instead be measured internal to the structure using embedded thermocouples, and direct and inverse methods can then be used to estimate temperature and heat flux on the external surface. Two thermocouples embedded at different depths are required to solve direct and inverse problems, and filtering schemes are used to reduce noise in the measured data. Accuracy in the estimated surface temperature and heat flux is dependent on several factors. Factors include the thermocouple location through the thickness of a material, the sensitivity of the surface solution to the error in the specified location of the embedded thermocouples, and the sensitivity to the error in thermocouple data. The effect of these factors on solution accuracy is studied using the methodology discussed in the work of Pizzo, et. al.1 A numerical study is performed to determine if there is an optimal depth at which to embed one thermocouple through the thickness of a material assuming that a second thermocouple is installed on the back face. Solution accuracy will be discussed for a range of embedded thermocouple depths. Moreover, the sensitivity of the surface solution to (a) the error in the specified location of the embedded thermocouple and to (b) the error in the thermocouple data are quantified using numerical simulation, and the results are discussed.

The use of thermocouples which transmute during service in nuclear reactors

International Nuclear Information System (INIS)

Martin, R.E.

1980-06-01

Some current nuclear fuel experiments at CRNL require the use of thermocouples to measure temperatures of up to 2200 0 C under reactor operating conditions. A literature search has shown that transient electrical effects and transmutation of the thermocouple alloys can cause temperature measurement errors of up to +-1% and +-30%, respectively. However, the error due to transient electrical effects can be corrected by making temperature measurements immediately following reactor shutdown. Furthermore it has been shown that transmutation effects can be corrected for by calibrating the high temperature tungsten-rhenium thermocouples against a chromel-alumel thermocouple in a cooler part of the experiment. The use of these techniques is expected to reduce temperature measurement errors to +-2% in the best case. (auth)

Development of a micro-thermal flow sensor with thin-film thermocouples

Science.gov (United States)

Kim, Tae Hoon; Kim, Sung Jin

2006-11-01

A micro-thermal flow sensor is developed using thin-film thermocouples as temperature sensors. A micro-thermal flow sensor consists of a heater and thin-film thermocouples which are deposited on a quartz wafer using stainless steel masks. Thin-film thermocouples are made of standard K-type thermocouple materials. The mass flow rate is measured by detecting the temperature difference of the thin-film thermocouples located in the upstream and downstream sections relative to a heater. The performance of the micro-thermal flow sensor is experimentally evaluated. In addition, a numerical model is presented and verified by experimental results. The effects of mass flow rate, input power, and position of temperature sensors on the performance of the micro-thermal flow sensor are experimentally investigated. At low values, the mass flow rate varies linearly with the temperature difference. The linearity of the micro-thermal flow sensor is shown to be independent of the input power. Finally, the position of the temperature sensors is shown to affect both the sensitivity and the linearity of the micro-thermal flow sensor.

Mineral insulated thermocouples - installation in steam generating plant

International Nuclear Information System (INIS)

Bridges, W.J.; Brown, J.F.

1980-01-01

The main areas of interest considered are Central Station Fossil Fuel fired boilers of around 500 MW capacity, AGR Boilers, and Industrial and Research Development projects. While the requirement for temperature measurement in each of these areas may vary the techniques adopted to overcome installation and protection problems created by thermal, chemical and mechanical hazards remain basically the same. The reasons for temperature measurement are described together with methods of attachment development and procedures for protection of the thermocouple along its route length until its exit from the hazardous environment. These relative accuracies of the different attachments are discussed along with factors influencing the life of the thermocouple. In many instances thermocouple installation is either a once only opportunity and/or an expensive exercise. It is therefore essential to develop and apply an effective quality control system during the installation phase. An effective system is described. Finally, a brief outline of possible future trends is given. (author)

Cladding temperature measurement by thermocouples at preirradiated LWR fuel rod samples

International Nuclear Information System (INIS)

Leiling, W.

1981-12-01

This report describes the technique to measure cladding temperatures of test fuel rod samples, applied during the in-pile tests on fuel rod failure in the steam loop of the FR2 reactor. NiCr/Ni thermocouples with stainless steel and Inconel sheaths, respectively,of 1 mm diameter were resistance spot weld to the outside of the fuel rod cladding. For the pre-irradiated test specimens, welding had to be done under hot-cell conditions, i.e. under remote handling. In order to prevent the formation of eutectics between zirconium and the chemical elements of the thermocouple sheath at elevated temperatures, the thermocouples were covered with a platinum jacket of 1.4 mm outside diameter swaged onto the sheath in the area of the measuring junction. This thermocouple design has worked satisfactorily in the in-pile experiments performed in a steam atmosphere. Even in the heatup phase, in which cladding temperatures up to 1050 0 C were reached, only very few failures occured. This good performance is to a great part due to a careful control and a thorough inspection of the thermocouples. (orig.) [de

Core exit thermocouple upgrade at Zion station

International Nuclear Information System (INIS)

Ulinski, T.M.; Ferg, D.A.

1989-01-01

Following the Three Mile Island accident, the ability of the core exit thermocouple (CET) system to monitor reactor core conditions and core cooling status became a requirement of the U.S. Nuclear Regulatory Commission (NRC). Since the thermocouple system at Zion station was not originally required for postaccident monitoring, Commonwealth Edison Company (CECo) committed to upgrading the CET system and to installing a subcooling margin monitoring (SMM) system. The significance of this commitment was that CECo proposed to accomplish the upgrade effort using internal resources and by developing the required in-house expertise instead of procuring integrated packages from several nuclear steam supply system vendors. The result was that CECo was able to demonstrate a number of new capabilities and unique design features with a significant cost savings. These included a qualified connector with an integral thermocouple cold-reference junction temperature compensation; the design, assembly, testing, and installation of a seismically qualified class 1E microprocessor; a commercial-grade dedication/upgrade process for safety-related hardware; a human factors review capability, and a verification and validation program for safety-related software. A discussion of these new capabilities and details of the design features is presented in this paper

Failure of sheathed thermocouples due to thermal cycling

International Nuclear Information System (INIS)

Anderson, R.L.; Ludwig, R.L.

1982-03-01

Open circuit failures (up to 100%) in small-diameter thermocouples used in electrically heated nuclear fuel rod simulator prototypes during thermal cycling tests were investigated to determine the cause(s) of the failures. The experiments conducted to determine the relative effects of differential thermal expansion, wire size, grain size, and manufacturing technology are described. It was concluded that the large grain size and embrittlement which result from certain common manufacturing annealing and drawing procedures were a major contributing factor in the breakage of the thermocouple wires

Lifetime improvement of sheathed thermocouples for use in high-temperature and thermal transient operations

International Nuclear Information System (INIS)

McCulloch, R.W.; Clift, J.H.

1982-01-01

Premature failure of small-diameter, magnesium-oxide-insulated sheathed thermocouples occurred when they were placed within nuclear fuel rod simulators (FRSs) to measure high temperatures and to follow severe thermal transients encountered during simulation of nuclear reactor accidents in Oak Ridge National Laboratory (ORNL) thermal-hydraulic test facilities. Investigation of thermally cycled thermocouples yielded three criteria for improvement of thermocouple lifetime: (1) reduction of oxygen impurities prior to and during their fabrication, (2) refinement of thermoelement grain size during their fabrication, and (3) elimination of prestrain prior to use above their recrystallization temperature. The first and third criteria were satisfied by improved techniques of thermocouple assembly and by a recovery anneal prior to thermocouple use

Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

International Nuclear Information System (INIS)

Kanjilal, S.K.

1994-01-01

This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1

Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

Energy Technology Data Exchange (ETDEWEB)

Kanjilal, S.K.

1994-12-06

This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1.

An experimental study of the effect of external thermocouples on rewetting during reflood

International Nuclear Information System (INIS)

Shires, G.L.; Butcher, A.A.; Carpenter, B.G.; McCune, D.S.; Pearson, K.G.

1980-04-01

The validation of computer codes used for PWR safety assessment often depends upon experiments carried out with either real fuel pins or electrically heated fuel pin simulators. In some cases, and this applies particularly to in-pile tests, temperatures are measured by means of sheathed thermocouples attached externally to the pins and this raises the question of the possible effect of such thermocouples on the two phase hydraulics and heat transfer which are being studied. This paper describes the experiments which subjected two realistic fuel pin simulators, one with and one without external thermocouples, to identical bottom flooding conditions. They demonstrate very clearly that external thermocouples act as preferential rewetting sites and thereby increase the rate of propagation of the quench front. In the view of the authors of this paper the facts described raise serious doubts about the validity of rewetting data obtained from experiments employing external thermocouples. (U.K.)

A Modified Design of a Thermocouple Based Digital Temperature Indicator with Opto-Isolation

Directory of Open Access Journals (Sweden)

S. C. BERA

2008-01-01

Full Text Available In the conventional thermocouple based digital temperature indicator the millivolt signal obtained from a thermocouple is first amplified and then converted into a digital signal by using analog-to-digital converter (ADC. This digital signal is then indicated as digital display of temperature using digital counter circuit or microprocessor/microcontroller based circuitry. In the present paper a modified AD conversion technique along with opto-isolation is used to indicate digitally the temperature without using any conventional analog-to-digital converter. The theory and design of the measuring technique are described in the paper. The non-linearity of thermocouple is eliminated by using look-up table within software program. The performance of the circuit has been experimentally tested by using mV input signal instead of a thermocouple as well as using a K-type thermocouple. The experimental results are reported in the paper.

Thermoelectric properties of currently available Au/Pt thermocouples related to the valid reference function

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Edler F.

2015-01-01

Full Text Available Au/Pt thermocouples are considered to be an alternative to High Temperature Standard Platinum Resistance Thermometers (HTSPRTs for realizing temperatures according to the International Temperature Scale of 1990 (ITS-90 in the temperature range between aluminium (660.323 °C and silver (961.78 °C. The original aim of this work was to develop and to validate a new reference function for Au/Pt thermocouples which reflects the properties of presently commercially available Au and Pt wires. The thermoelectric properties of 16 Au/Pt thermocouples constructed at different National Metrological Institutes by using wires from different suppliers and 4 commercially available Au/Pt thermocouples were investigated. Most of them exhibit significant deviations from the current reference function of Au/Pt thermocouples caused by the poor performance of the Au-wires available. Thermoelectric homogeneity was investigated by measuring immersion profiles during freezes at the freezing point of silver and in liquid baths. The thermoelectric inhomogeneities were found to be one order of magnitude larger than those of Au/Pt thermocouples of the Standard Reference Material® (SRM® 1749. The improvement of the annealing procedure of the gold wires is a key process to achieve thermoelectric homogeneities in the order of only about (2–3 mK, sufficient to replace the impracticable HTSPRTs as interpolation instruments of the ITS-90. Comparison measurements of some of the Au/Pt thermocouples against a HTSPRT and an absolutely calibrated radiation thermometer were performed and exhibit agreements within the expanded measurement uncertainties. It has been found that the current reference function of Au/Pt thermocouples reflects adequately the thermoelectric properties of currently available Au/Pt thermocouples.

Magnetic tunnel junction thermocouple for thermoelectric power harvesting

Science.gov (United States)

Böhnert, T.; Paz, E.; Ferreira, R.; Freitas, P. P.

2018-05-01

The thermoelectric power generated in magnetic tunnel junctions (MTJs) is determined as a function of the tunnel barrier thickness for a matched electric circuit. This study suggests that lower resistance area product and higher tunnel magnetoresistance will maximize the thermoelectric power output of the MTJ structures. Further, the thermoelectric behavior of a series of two MTJs, a MTJ thermocouple, is investigated as a function of its magnetic configurations. In an alternating magnetic configurations the thermovoltages cancel each other, while the magnetic contribution remains. A large array of MTJ thermocouples could amplify the magnetic thermovoltage signal significantly.

Thermocouple Errors when Mounted on Cylindrical Surfaces in Abnormal Thermal Environments.

Energy Technology Data Exchange (ETDEWEB)

Nakos, James T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Suo-Anttila, Jill M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zepper, Ethan T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Koenig, Jerry J [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Valdez, Vincent A. [ECI Inc., Albuquerque, NM (United States)

2017-05-01

Mineral-insulated, metal-sheathed, Type-K thermocouples are used to measure the temperature of various items in high-temperature environments, often exceeding 1000degC (1273 K). The thermocouple wires (chromel and alumel) are protected from the harsh environments by an Inconel sheath and magnesium oxide (MgO) insulation. The sheath and insulation are required for reliable measurements. Due to the sheath and MgO insulation, the temperature registered by the thermocouple is not the temperature of the surface of interest. In some cases, the error incurred is large enough to be of concern because these data are used for model validation, and thus the uncertainties of the data need to be well documented. This report documents the error using 0.062" and 0.040" diameter Inconel sheathed, Type-K thermocouples mounted on cylindrical surfaces (inside of a shroud, outside and inside of a mock test unit). After an initial transient, the thermocouple bias errors typically range only about +-1-2% of the reading in K. After all of the uncertainty sources have been included, the total uncertainty to 95% confidence, for shroud or test unit TCs in abnormal thermal environments, is about +-2% of the reading in K, lower than the +-3% typically used for flat shrouds. Recommendations are provided in Section 6 to facilitate interpretation and use of the results. .

Measurement errors for thermocouples attached to thin plates

International Nuclear Information System (INIS)

Sobolik, K.B.; Keltner, N.R.; Beck, J.V.

1989-01-01

This paper discusses Unsteady Surface Element (USE) methods which are applied to a model of a thermocouple wire attached to a thin disk. Green's functions are used to develop the integral equations for the wire and the disk. The model can be used to evaluate transient and steady state responses for many types of heat flux measurement devices including thin skin calorimeters and circular foil (Gardon) head flux gauges. The model can accommodate either surface or volumetric heating of the disk. The boundary condition at the outer radius of the disk can be either insulated or constant temperature. Effect on the errors of geometrical and thermal factors can be assessed. Examples are given

An Innovative Flow-Measuring Device: Thermocouple Boundary Layer Rake

Science.gov (United States)

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

2001-01-01

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.

Low drift type N thermocouples in out-of-pile advanced gas reactor mock-up test: metallurgical analysis

International Nuclear Information System (INIS)

Scervini, M.; Palmer, J.; Haggard, D.C.; Swank, W.D.

2015-01-01

Thermocouples are the most commonly used sensors for temperature measurement in nuclear reactors. They are crucial for the control of current nuclear reactors and for the development of GEN IV reactors. In nuclear applications thermocouples are strongly affected by intense neutron fluxes. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition and, as a consequence, a time dependent drift of the thermocouple signal. Thermocouple drift can be very significant for in-pile temperature measurements and may render the temperature sensors unreliable after exposure to nuclear radiation for relatively short times compared to the life required for temperature sensors in nuclear applications. Previous experiences with type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly type N thermocouples are expected to be only slightly affected by neutron fluxes. Currently the use of Nickel based thermocouples is limited to temperatures lower than 1000 deg. C due to drift related to phenomena other than nuclear irradiation. As part of a collaboration between Idaho National Laboratory (INL) and the University of Cambridge a variety of Type N thermocouples have been exposed at INL in an Advanced Gas Reactor mock-up test at 1150 deg. C for 2000 h, 1200 deg. C for 2000 h, 125 deg. C for 200 h and 1300 deg. C for 200 h, and later analysed metallurgically at the University of Cambridge. The use of electron microscopy allows to identify the metallurgical changes occurring in the thermocouples during high temperature exposure and correlate the time dependent thermocouple drift with the microscopic changes experienced by the thermoelements of different thermocouple designs. In this paper conventional Inconel 600 sheathed type N thermocouples and a type N using a customized sheath developed at the University of

Low drift type N thermocouples in out-of-pile advanced gas reactor mock-up test: metallurgical analysis

Energy Technology Data Exchange (ETDEWEB)

Scervini, M. [University of Cambridge, Department of Materials Science and Metallurgy, 27 Charles Babbage Road, CB30FS Cambridge, (United Kingdom); Palmer, J.; Haggard, D.C.; Swank, W.D. [Idaho National Laboratory, Idaho Falls, ID 83415-3840, (United States)

2015-07-01

Thermocouples are the most commonly used sensors for temperature measurement in nuclear reactors. They are crucial for the control of current nuclear reactors and for the development of GEN IV reactors. In nuclear applications thermocouples are strongly affected by intense neutron fluxes. As a result of the interaction with neutrons, the thermoelements of the thermocouples undergo transmutation, which produces a time dependent change in composition and, as a consequence, a time dependent drift of the thermocouple signal. Thermocouple drift can be very significant for in-pile temperature measurements and may render the temperature sensors unreliable after exposure to nuclear radiation for relatively short times compared to the life required for temperature sensors in nuclear applications. Previous experiences with type K thermocouples in nuclear reactors have shown that they are affected by neutron irradiation only to a limited extent. Similarly type N thermocouples are expected to be only slightly affected by neutron fluxes. Currently the use of Nickel based thermocouples is limited to temperatures lower than 1000 deg. C due to drift related to phenomena other than nuclear irradiation. As part of a collaboration between Idaho National Laboratory (INL) and the University of Cambridge a variety of Type N thermocouples have been exposed at INL in an Advanced Gas Reactor mock-up test at 1150 deg. C for 2000 h, 1200 deg. C for 2000 h, 125 deg. C for 200 h and 1300 deg. C for 200 h, and later analysed metallurgically at the University of Cambridge. The use of electron microscopy allows to identify the metallurgical changes occurring in the thermocouples during high temperature exposure and correlate the time dependent thermocouple drift with the microscopic changes experienced by the thermoelements of different thermocouple designs. In this paper conventional Inconel 600 sheathed type N thermocouples and a type N using a customized sheath developed at the University of

Establishment of the Co-C Eutectic Fixed-Point Cell for Thermocouple Calibrations at NIMT

Science.gov (United States)

Ongrai, O.; Elliott, C. J.

2017-08-01

In 2015, NIMT first established a Co-C eutectic temperature reference (fixed-point) cell measurement capability for thermocouple calibration to support the requirements of Thailand's heavy industries and secondary laboratories. The Co-C eutectic fixed-point cell is a facility transferred from NPL, where the design was developed through European and UK national measurement system projects. In this paper, we describe the establishment of a Co-C eutectic fixed-point cell for thermocouple calibration at NIMT. This paper demonstrates achievement of the required furnace uniformity, the Co-C plateau realization and the comparison data between NIMT and NPL Co-C cells by using the same standard Pt/Pd thermocouple, demonstrating traceability. The NIMT measurement capability for noble metal type thermocouples at the new Co-C eutectic fixed point (1324.06°C) is estimated to be within ± 0.60 K (k=2). This meets the needs of Thailand's high-temperature thermocouple users—for which previously there has been no traceable calibration facility.

Evaluation of thermocouple fin effect in cladding surface temperature measurement during film boiling

International Nuclear Information System (INIS)

Tsuruta, Takaharu; Fujishiro, Toshio

1984-01-01

Thermocouple fin effect on surface temperature measurement of a fuel rod has been studied at elevated wall temperatures under film boiling condition in a reactivity initiated accident (RIA) situation. This paper presents an analytical equation to evaluate temperature drops caused by the thermocouple wires attached to cladding surface. The equation yielded the local temperature drop at measuring point depending on thermocouple diameter, cladding temperature, coolant flow condition and vapor film thickness. The temperature drops by the evaluating equation were shown in cases of free and forced convection conditions. The analytical results were compared with the measured data for various thermocouple sizes, and also with the estimated maximum cladding temperature based on the oxidation layer thickness in the cladding outer surface. It was concluded that the temperature drops at above 1,000 0 C in cladding temperature were around 120 and 150 0 C for 0.2 and 0.3 mm diameter Pt-Pt.Rh thermocouples, respectively, under a stagnant coolant condition. The fin effect increases with the decrease of vapor film thickness such as under forced flow cooling or at near the quenching point. (author)

Thermocouple Rakes for Measuring Boundary Layer Flows Extremely Close to Surface

Science.gov (United States)

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

2001-01-01

Of vital interest to aerodynamic researchers is precise knowledge of the flow velocity profile next to the surface. This information is needed for turbulence model development and the calculation of viscous shear force. Though many instruments can determine the flow velocity profile near the surface, none of them can make measurements closer than approximately 0.01 in. from the surface. The thermocouple boundary-layer rake can measure much closer to the surface than conventional instruments can, such as a total pressure boundary layer rake, hot wire, or hot film. By embedding the sensors (thermocouples) in the region where the velocity is equivalent to the velocity ahead of a constant thickness strut, the boundary-layer flow profile can be obtained. The present device fabricated at the NASA Glenn Research Center microsystem clean room has a heater made of platinum and thermocouples made of platinum and gold. Equal numbers of thermocouples are placed both upstream and downstream of the heater, so that the voltage generated by each pair at the same distance from the surface is indicative of the difference in temperature between the upstream and downstream thermocouple locations. This voltage differential is a function of the flow velocity, and like the conventional total pressure rake, it can provide the velocity profile. In order to measure flow extremely close to the surface, the strut is made of fused quartz with extremely low heat conductivity. A large size thermocouple boundary layer rake is shown in the following photo. The latest medium size sensors already provide smooth velocity profiles well into the boundary layer, as close as 0.0025 in. from the surface. This is about 4 times closer to the surface than the previously used total pressure rakes. This device also has the advantage of providing the flow profile of separated flow and also it is possible to measure simultaneous turbulence levels within the boundary layer.

Thermocouples calibration and analysis of the influence of the length of the sensor coating

International Nuclear Information System (INIS)

Noriega, M; Ramírez, R; López, R; Vaca, M; Morales, J; Terres, H; Lizardi, A; Chávez, S

2015-01-01

This paper presents the design and construction of a lab prototype, with a much lower cost compared to the ones commercially sold, enabling the manufacture of thermocouples which are then calibrated to verify their functionality and acceptance. We also analyze the influence of the external insulation over the wires, to determine whether it influences temperature measurement. The tested lengths ranged from 0.00 m up to 0.030 m. The thermocouple was compared against the behavior of a thermocouple of the same type that was purchased with a commercial supplier. The obtained measurement showed less than 1 °C difference in some points. This makes the built thermocouple reliable, since the standard allows a difference of up to 2.2 °C

Preparation and Thermoelectric Characteristics of ITO/PtRh:PtRh Thin Film Thermocouple.

Science.gov (United States)

Zhao, Xiaohui; Wang, Hongmin; Zhao, Zixiang; Zhang, Wanli; Jiang, Hongchuan

2017-12-15

Thin film thermocouples (TFTCs) can provide more precise in situ temperature measurement for aerospace propulsion systems without disturbance of gas flow and surface temperature distribution of the hot components. ITO/PtRh:PtRh TFTC with multilayer structure was deposited on alumina ceramic substrate by magnetron sputtering. After annealing, the TFTC was statically calibrated for multiple cycles with temperature up to 1000 °C. The TFTC with excellent stability and repeatability was realized for the negligible variation of EMF in different calibration cycles. It is believed that owing to oxygen diffusion barriers by the oxidation of top PtRh layer and Schottky barriers formed at the grain boundaries of ITO, the variation of the carrier concentration of ITO film is minimized. Meanwhile, the life time of TFTC is more than 30 h in harsh environment. This makes ITO/PtRh:PtRh TFTC a promising candidate for precise surface temperature measurement of hot components of aeroengines.

Direct Measurement of Neutral/Ion Beam Power using Thermocouple Analysis

International Nuclear Information System (INIS)

Day, I.; Gee, S.

2006-01-01

Modern Neutral Beam Injection systems such as those used on JET and MAST routinely use thermocouples embedded close to the surface of beam stopping elements, such as calorimeters and ion dumps, coupled to high speed data acquisition systems to determine beam profile and position from temperature rise data. With the availability of low cost data acquisition and storage systems it is now possible to record data from all thermocouples in a fully instrumented calorimeter or ion dump on 20 ms timescales or better. This sample rate is sufficiently fast to enable the thermocouple data to be used to calculate the incident power density from 1d heat transfer theory. This power density data coupled with appropriate Gaussian fits enables the determination of the 2d beam profile and thus allows an instantaneous and direct measurement of beam power. The theory and methodology required to analyse the fast thermocouple data from the MAST calorimeter and residual ion dump thermocouples is presented and direct measurements of beam power density are demonstrated. The power of desktop computers allows such analysis to be carried out virtually instantaneously. The methods used to automate this analysis are discussed in detail. A code, utilising the theory and methodology, has been developed to allow immediate measurements of beam power on a pulse by pulse basis. The uncertainty in determining the beam power density is shown to be less than 10 %. This power density data is then fitted to a 2d Gaussian beam profile and integrated to establish the total beam power. Results of this automated analysis for the neutral beam and residual ion power of the MAST duopigatron and PINI NBI systems are presented. This technology could be applied to a beam power safety interlock system. The application to a beam shine through protection system for the inner wall of the JET Tokamak is discussed as an example. (author)

Thermal Recovery from Cold-Working in Type K Bare-Wire Thermocouples

Science.gov (United States)

Greenen, A. D.; Webster, E. S.

2017-12-01

Cold-working of most thermocouples has a significant, direct impact on the Seebeck coefficient which can lead to regions of thermoelectric inhomogeneity and accelerated drift. Cold-working can occur during the wire swaging process, when winding the wire onto a bobbin, or during handling by the end user—either accidentally or deliberately. Swaging-induced cold-work in thermocouples, if uniformly applied, may result in a high level of homogeneity. However, on exposure to elevated temperatures, the subsequent recovery process from the cold-working can then result in significant drift, and this can in turn lead to erroneous temperature measurements, often in excess of the specified manufacturer tolerances. Several studies have investigated the effects of cold-work in Type K thermocouples usually by bending, or swaging. However, the amount of cold-work applied to the thermocouple is often difficult to quantify, as the mechanisms for applying the strains are typically nonlinear when applied in this fashion. A repeatable level of cold-working is applied to the different wires using a tensional loading apparatus to apply a known yield displacement to the thermoelements. The effects of thermal recovery from cold-working can then be accurately quantified as a function of temperature, using a linear gradient furnace and a high-resolution homogeneity scanner. Variation in these effects due to differing alloy compositions in Type K wire is also explored, which is obtained by sourcing wire from a selection of manufacturers. The information gathered in this way will inform users of Type K thermocouples about the potential consequences of varying levels of cold-working and its impact on the Seebeck coefficient at a range of temperatures between ˜ 70°C and 600° C. This study will also guide users on the temperatures required to rapidly alleviate the effects of cold-working using thermal annealing treatments.

Calibration Technique of the Irradiated Thermocouple using Artificial Neural Network

Energy Technology Data Exchange (ETDEWEB)

Hong, Jin Tae; Joung, Chang Young; Ahn, Sung Ho; Yang, Tae Ho; Heo, Sung Ho; Jang, Seo Yoon [KAERI, Daejeon (Korea, Republic of)

2016-05-15

To correct the signals, the degradation rate of sensors needs to be analyzed, and re-calibration of sensors should be followed periodically. In particular, because thermocouples instrumented in the nuclear fuel rod are degraded owing to the high neutron fluence generated from the nuclear fuel, the periodic re-calibration process is necessary. However, despite the re-calibration of the thermocouple, the measurement error will be increased until next re-calibration. In this study, based on the periodically calibrated temperature - voltage data, an interpolation technique using the artificial neural network will be introduced to minimize the calibration error of the C-type thermocouple under the irradiation test. The test result shows that the calculated voltages derived from the interpolation function have good agreement with the experimental sampling data, and they also accurately interpolate the voltages at arbitrary temperature and neutron fluence. That is, once the reference data is obtained by experiments, it is possible to accurately calibrate the voltage signal at a certain neutron fluence and temperature using an artificial neural network.

Temperature measurement: Development work on noise thermometry and improvement of conventional thermocouples for applications in nuclear process heat (PNP)

International Nuclear Information System (INIS)

Brixy, H.; Hecker, R.; Oehmen, J.; Barbonus, P.; Hans, R.

1982-06-01

The behaviour was studied of NiCr-Ni sheathed thermocouples (sheath Inconel 600 or Incoloy 800, insulation MgO) in a helium and carbon atmosphere at temperatures of 950-1150 deg. C. All the thermocouples used retained their functional performance. The insulation resistance tended towards a limit value which is dependent on the temperature and quality of the thermocouple. Temperature measurements were loaded with great uncertainty in the temperature range of 950-1150 deg. C. Recalibrations at the temperature of 950 deg. C showed errors of up to 6%. Measuring sensors were developed which consist of a sheathed double thermocouple with a noise resistor positioned between the two hot junctions. Using the noise thermometer it is possible to recalibrate the thermocouple at any time in situ. A helium system with a high temperature experimental area was developed to test the thermocouples and the combined thermocouple-noise thermometer sensors under true experimental conditions

A preliminary study of factors affecting the calibration stability of the iridium versus iridium-40 percent rhodium thermocouple

Science.gov (United States)

Ahmed, Shaffiq; Germain, Edward F.; Daryabeigi, Kamran; Alderfer, David W.; Wright, Robert E.

1987-01-01

An iridium versus iridium-40% rhodium thermocouple was studied. Problems associated with the use of this thermocouple for high temperature applications (up to 2000 C) were investigated. The metallurgical studies included X-ray, macroscopic, resistance, and metallographic studies. The thermocouples in the as-received condition from the manufacturer revealed large amounts of internal stress caused by cold working during manufacturing. The thermocouples also contained a large amount of inhomogeneities and segregations. No phase transformations were observed in the alloy up to 1100 C. It was found that annealing the thermocouple at 1800 C for two hours, and then at 1400 C for 2 to 3 hours yielded a fine grain structure, relieving some of the strains, and making the wire more ductile. It was also found that the above annealing procedure stabilized the thermal emf behavior of the thermocouple for application below 1800 C (an improvement from + or - 1% to + or - 0.02% within the range of the test parameters used).

Study on thermocouple attachment in reflood experiments

International Nuclear Information System (INIS)

Sugimoto, Jun

1977-03-01

The method of thermocouple attachment to a heater rods has been studied for surface temperature measurement in reflood experiments. The method used as far in JAERI's reflood experiments had some possibilities of not estimating exactly the quench times. Various attachment method have been tested and some proved to be effective in the respect. (auth.)

Zircaloy-sheathed element rods fitted with thermo-couples

International Nuclear Information System (INIS)

Bernardy de Sigoyer, B.; Jacques, F.; Thome, P.

1963-01-01

In order to carry out thermal conductivity measurements on UO 2 in conditions similar to those under which fuel rods are used, it was necessary to measure the temperature at the interior of a fuel element sheathed in zircaloy. The temperatures are taken with Thermocoax type thermocouples, that is to say fitted with a very thin sheath of stainless steel or Inconel. It is known also that fusion welding of zircaloy onto stainless steel is impossible and that high temperature welded joints are very difficult because of their aggressiveness. The technique used consists in brazing the thermocouples to relatively large stainless steel parts and then joining these plugs by electron bombardment welding to diffused stainless steel-zircaloy couplings. The properties of these diffused couplings and of the brazed joints were studied; the various stages in the fabrication of the containers are also described. (authors) [fr

R and D advances in high temperature thermocouples for nuclear utilization in severe environment

International Nuclear Information System (INIS)

Schley, R.; Blanc, J.Y.

1984-09-01

Safety experiments for water reactors in Cadarache have made necessary a research program for developing special thermocouples for use in severe fuel damage conditions (superheated steam). Standard cladding thermocouples (type K, alumina insulated, zircaloy sheathed, O.D. 0.7 mm) must be replaced by others with W3Re versus W25Re legs, Ta sheath protected by a zircaloy outer sheath, and hafnia or thoria insulation. The zircaloy sheath will be sufficient to protect correctly tantalum. Fuel centerline thermocouples have W5Re versus W26Re or W3Re versus W25Re legs, hard-fired thoria insulation and rhenium CVD sheath (O.D. 1.1 mm). A protective ReSi 2 coating is applied. This protection withstands at least 1600 0 C, 45 minutes in steam. Tests are done-concerning: a) materials compatibilities in helium between 1400 0 C and 2000 0 C, b) prototypes qualification (in Saclay or Grenoble), c) determination of errors due to degradation of insulation resistance of thermocouples cables (with magnesia, hafnia, alumina), d) Ir or Re protective coatings by CVD process, other coatings by ionic bombardment, etc... A completely new type of hot junction has been patented. Future works will include: completion of these tests, Mo-Nb alloys thermocouples legs realization withstanding heavy neutronic fluence, and use of ceramics glues

Temperature measurement error due to the effects of time varying magnetic fields on thermocouples with ferromagnetic thermoelements

International Nuclear Information System (INIS)

McDonald, D.W.

1977-01-01

Thermocouples with ferromagnetic thermoelements (iron, Alumel, Nisil) are used extensively in industry. We have observed the generation of voltage spikes within ferromagnetic wires when the wires are placed in an alternating magnetic field. This effect has implications for thermocouple thermometry, where it was first observed. For example, the voltage generated by this phenomenon will contaminate the thermocouple thermal emf, resulting in temperature measurement error

78 FR 56174 - In-Core Thermocouples at Different Elevations and Radial Positions in Reactor Core

Science.gov (United States)

2013-09-12

... 52 [Docket No. PRM-50-105; NRC-2012-0056] In-Core Thermocouples at Different Elevations and Radial Positions in Reactor Core AGENCY: Nuclear Regulatory Commission. ACTION: Petition for rulemaking; denial...-core thermocouples at different elevations and radial positions throughout the reactor core to enable...

Analysis of heat transfer from fuel rods with externally attached thermocouples

International Nuclear Information System (INIS)

Gill, C.R.; Coddington, P.

1988-05-01

This paper describes the development of 2 and 3 dimensional finite element heat conduction models to simulate the behaviour of the external thermocouples attached to the LOFT fuel rods during the blowdown phase of a large break loss-of-coolant accident. To establish the model and determine the thermal coupling between the thermocouple and the fuel rod extensive use was made of two series of experiments performed at INEL in the LOFT Test Support Facility (LTSF). These experiments were high pressure reflood experiments with fluid conditions 'typical' of those seen during the bottom-up flow period of the LOFT experiments. (author)

77 FR 30435 - In-core Thermocouples at Different Elevations and Radial Positions in Reactor Core

Science.gov (United States)

2012-05-23

... NUCLEAR REGULATORY COMMISSION 10 CFR Part 50 [Docket No. PRM-50-105; NRC-2012-0056] In-core Thermocouples at Different Elevations and Radial Positions in Reactor Core AGENCY: Nuclear Regulatory Commission... of operating licenses for nuclear power plants (``NPP'') to operate NPPs with in-core thermocouples...

Difference equation approach to two-thermocouple sensor characterization in constant velocity flow environments

International Nuclear Information System (INIS)

Hung, P.C.; Irwin, G.; Kee, R.; McLoone, S.

2005-01-01

Thermocouples are one of the most popular devices for temperature measurement due to their robustness, ease of manufacture and installation, and low cost. However, when used in certain harsh environments, for example, in combustion systems and engine exhausts, large wire diameters are required, and consequently the measurement bandwidth is reduced. This article discusses a software compensation technique to address the loss of high frequency fluctuations based on measurements from two thermocouples. In particular, a difference equation (DE) approach is proposed and compared with existing methods both in simulation and on experimental test rig data with constant flow velocity. It is found that the DE algorithm, combined with the use of generalized total least squares for parameter identification, provides better performance in terms of time constant estimation without any a priori assumption on the time constant ratios of the thermocouples

Comparative evaluation of corrosion behaviour of type K thin film thermocouple and its bulk counterpart

International Nuclear Information System (INIS)

Mukherjee, S.K.; Barhai, P.K.; Srikanth, S.

2011-01-01

Highlights: → Anodic vacuum arc deposited chromel and alumel films are more 'noble' in 5% NaCl solution than their respective wires. → Chromel undergoes localised corrosion while alumel shows uniform corrosion. → Virgin samples of chromel-alumel TFTCs exhibit good thermoelectric response. → Their thermoelectric outputs remain largely unaffected when shelved under normal atmospheric conditions. → After 288 h of exposure in salt spray environment, their thermoelectric outputs show noticeable change due to size effects. - Abstract: This paper investigates the corrosion behaviour of type K thermoelements and their thin films, and compares the performance of chromel-alumel thin film thermocouple with its wire counterpart before and after exposure to 5% NaCl medium. Potentiodynamic polarisation tests reveal that chromel and alumel films are more 'noble' than their respective wires. Alumel corrodes faster when coupled with chromel in films than as wires. Secondary electron micrographs and electrochemical impedance spectroscopy measurements suggest that chromel shows localised corrosion while alumel undergoes uniform corrosion. Corrosion adversely affects the thermocouple output and introduces an uncertainty in the measurement.

Determination of the availability of core exit thermocouples during severe accident situations

International Nuclear Information System (INIS)

Edson, J.L.

1985-04-01

This report presents the findings and recommendations of the Nuclear Power Plant Instrumentation Evaluation (NPPIE) program concerning signal validation methods to determine the on-line availability of core exit thermocouples during accident situations. Methods of selecting appropriate signal validation techniques are discussed and sources of error identified. This report shows that through the use of these techniques the existence of high-temperature-caused errors may be detected as they occur. Specific recommendations for application of selected signal validation techniques to core exit thermocouples and other measurement systems are made. 23 refs., 22 figs., 3 tabs

Classification of Unknown Thermocouple Types Using Similarity Factor Measurement

Directory of Open Access Journals (Sweden)

Seshu K. DAMARLA

2011-01-01

Full Text Available In contrast to classification using PCA method, a new methodology is proposed for type identification of unknown thermocouple. The new methodology is based on calculating the degree of similarity between two multivariate datasets using two types of similarity factors. One similarity factor is based on principle component analysis and the angles between the principle component subspaces while the other is based on the Mahalanobis distance between the datasets. Datasets containing thermo-emfs against given temperature ranges are formed for each type of thermocouple (e.g. J, K, S, T, R, E, B and N type by experimentation are considered as reference datasets. Datasets corresponding to unknown type are captured. Similarity factor between the datasets one of which being the unknown type and the other being each known type are compared. When maximum similarity factor occurs, then the class of unknown type is allocated to that of known type.

The disposition of can thermocouples in a nuclear reactor

International Nuclear Information System (INIS)

Wilkie, D.

1978-01-01

A philosophy is presented for deciding the distribution of can thermocouples within channels and of instrumented channels throughout the core of a reactor with cluster-type fuel elements when only a few thermocouples can be located in any one channel. The arrangement is made according to a 'factorial' design in which all fuel element positions of interest are covered in a group of channels. Two types of factorial design can be applied: the unconfounded design by which the thermocouples in each channel are chosen at random from the possible positions available, with the results that the temperatures have attached to them an uncertainty determined by the differences among channels; and the confounded design by which the positions are chosen so as to give temperatures whose uncertainty is determined only by the random variations within channels. It is also necessary to estimate standard deviations in order to predict the number of cans likely to reach a given temperature. The standard deviation can be expected to vary with channel position, and since there will also be systematic variations in temperature with channel position it is necessary to arrange channels into groups having similar mean fluxes and flux distributions. Each group is instrumented according to the pattern of a confounded design. The information that such an arrangement provides is an estimate of the systematic temperature variations within channels, estimates of within-channel variation of can temperature, of between-channel variation of can temperature, and of the variation of these quantities among groups of channels grouped according to similarity of mean flux and flux profile. (author)

Thermocouple module halt failure acceptance test procedure for Tank 241-SY-101 DACS-1

International Nuclear Information System (INIS)

Ermi, A.M.

1997-01-01

The readiness of the Tank 241-SY-101 Data Acquisition and Control System (DACS-1) to provide monitoring and alarms for a halt failure of any thermocouple module will be tested during the performance of this procedure. Updated DACS-1 ''1/0 MODULE HEALTH STATUS'', ''MININ1'', and ''MININ2'' screens, which now provide indication of thermocouple module failure, will also be tested as part of this procedure

Energy deposition measurements in fast reactor safety experiments with fission thermocouple detectors

International Nuclear Information System (INIS)

Wright, S.A.; Scott, H.L.

1979-01-01

The investigation of phenomena occurring in in-pile fast reactor safety experiments requires an accurate measurement of the time dependent energy depositions within the fissile material. At Sandia Laboratories thin-film fission thermocouples are being developed for this purpose. These detectors have high temperature capabilities (400 to 500 0 C), are sodium compatible, and have milli-second time response. A significant advantage of these detectors for use as energy deposition monitors is that they produce an output voltage which is directly dependent on the temperature of a small chip of fissile material within the detectors. However, heat losses within the detector make it necessary to correct the response of the detector to determine the energy deposition. A method of correcting the detector response which uses an inverse convolution procedure has been developed and successfully tested with experimental data obtained in the Sandia Pulse Reactor (SPR-II) and in the Annular Core Research Reactor

Temperature transient response measurement in flowing water

International Nuclear Information System (INIS)

Rainbird, J.C.

1980-01-01

A specially developed procedure is described for determining the thermal transient response of thermocouples and other temperature transducers when totally immersed in flowing water. The high velocity heat transfer conditions associated with this facility enable thermocouple response times to be predicted in other fluids. These predictions can be confirmed by electrical analogue experiments. (author)

Evaluation of RTD and thermocouple for PID temperature control in ...

African Journals Online (AJOL)

Evaluation of RTD and thermocouple for PID temperature control in distributed control system laboratory. D. A. A. Nazarudin, M. K. Nordin, A. Ahmad, M. Masrie, M. F. Saaid, N. M. Thamrin, M. S. A. M. Ali ...

Development of thermocouple re-instrumentation technique for irradiated fuel rod. Techniques for making center hole into UO2 pellets and thermocouple re-instrumentation to fuel rod

International Nuclear Information System (INIS)

Shimizu, Michio; Saito, Junichi; Oshima, Kunio

1995-07-01

The information on FP gas pressure and centerline temperature of fuel pellets during power transient is important to study the pellet clad interaction (PCI) mechanism of high burnup LWR fuel rods. At the Department of JMTR, a re-instrumentation technique of FP gas pressure gage for an irradiated fuel rod was developed in 1990. Furthermore, a thermocouple re-instrumentation technique was successfully developed in 1994. Two steps were taken to carry out the development program of the thermocouple re-instrumentation technique. In the first step, a drilling technique was developed for making a center hole of the irradiated fuel pellets. Various drilling tests were carried out using dummy of fuel rods consisted of Ba 2 FeO 3 pellets and Zry-2 cladding. On this work it is important to keep the pellets just the state cracked at a power reactor. In these tests, the technique to fix the pellets by frozen CO 2 was used during the drilling work. Also, diamond drills were used to make the center hole. These tests were completed successfully. A center hole, 54mm depth and 2.5mm diameter, was realized by these methods. The second step of this program is the in-pile demonstration test on an irradiated fuel rod instrumented dually a thermocouple and FP gas pressure gage. The demonstration test was carried out at the JMTR in 1995. (author)

Relocation work of temporary thermocouples for measuring the vessel cooling system in the safety demonstration test

International Nuclear Information System (INIS)

Shimazaki, Yosuke; Shinohara, Masanori; Ono, Masato; Yanagi, Shunki; Tochio, Daisuke; Iigaki, Kazuhiko

2012-05-01

It is necessary to confirm that the temperature of water cooling panel of the vessel cooling system (VCS) is controlled under the allowable working temperature during the safety demonstration test because the water cooling panel temperature rises due to stop of cooling water circulation pumps. Therefore, several temporary thermocouples are relocated to the water cooling panel near the stabilizers of RPV and the side cooling panel outlet ring header of VCS in order to observe the temperature change of VCS. The relocated thermocouples can measure the temperature change with starting of the cooling water circulation pumps of VCS. So it is confirmed that the relocated thermocouples can observe the VCS temperature change in the safety demonstration test. (author)

Apparatus for spot welding sheathed thermocouples to the inside of small-diameter tubes at precise locations

International Nuclear Information System (INIS)

Baucum, W.E.; Dial, R.E.

1976-01-01

Equipment and procedures used to spot weld tantalum- or stainless-steel-sheathed thermocouples to the inside diameter of Zircaloy tubing to meet the requirements of the Multirod Burst Test (MRBT) Program at ORNL are described. Spot welding and oxide cleaning tools were fabricated to remove the oxide coating on the Zircaloy tubing at local areas and spot weld four thermocouples separated circumferentially by 90 0 at any axial distribution desired. It was found necessary to apply a nickel coating to stainless-steel-sheathed thermocouples to obtain acceptable welds. The material and shape of the inner electrode and resistance between inner and outer electrodes were found to be critical parameters in obtaining acceptable welds

Accuracy of small diameter sheathed thermocouples for the core flow test loop

International Nuclear Information System (INIS)

Anderson, R.L.; Kollie, T.G.

1979-04-01

This report summarizes the research and development on 0.5-mm-diameter, compacted, metal sheathed thermocouples. The objectives of this research effort have been: to identify and analyze the sources of temperature measurement errors in the use of 0.5-mm-diameter sheathed thermocouples to measure the surface temperature of the cladding of fuel-rod simulators in the Core Flow Test Loop (CFTL) at ORNL; to devise methods for reducing or correcting for these temperature measurement errors; to estimate the overall temperature measurement uncertainties; and to recommend modifications in the manufacture, installation, or materials used to minimize temperature measurement uncertainties in the CFTL experiments

Manifestations of nonlinearity in fuel center thermocouple steady-state and transient data: implications for data analysis

International Nuclear Information System (INIS)

Lanning, D.D.; Barnes, B.O.; Williford, R.E.

1979-01-01

The interpretation and verification of fuel centerline thermocouple data are analyzed. Two new concepts are discussed along with their application to in-reactor data from IFA-432, a heavily instrumented six-rod Halden reactor test assembly sponsored by the Nuclear Regulatory Commission. The main ideas presented in this report are that: it is more useful to plot resistance versus power than simply to plot temperature versus power; and the response of the centerline temperature to a linear power decrease is correlated to the rod's current resistance-vs-power behavior. Thus, the resistance-vs-power measurement can be verified by performing a linear power decrease and by plotting the temperature response

Experience from replacement and check of thermocouples during reconstruction of in-reactor temperature measurements at Bohunice V-1 units 1 and 2

International Nuclear Information System (INIS)

Slanina, M.; Stanc, J.

2001-01-01

Replacement of thermocouples in the protection tube blocks was a key phase of the reconstruction of in-reactor temperature measurements at Bohunice V-1 with regard to the success, reliability and impact on safety of unit operation. The replacement consisted of reliable and safe withdrawal of 216 old thermocouples, their disposal and installation of new thermocouples into dry channels. In the material presented, this phase of reconstruction is described in details, with focus on the evaluation of replacement quality and check activities carried out at the new installed thermocouples. (Authors)

Temperature Control System for Chromel-Alumel Thermocouple

International Nuclear Information System (INIS)

Piping Supriatna; Nurhanan; Riswan DJ; Heru K, B.; Edi Karyanta

2003-01-01

Nuclear Power Plan Operation Safety needs serious handling on temperature measurement and control. In this report has been done manufacturing Temperature Control System for Chromel-Alumel Thermocouple, accordance to material, equipment and human resource ability in the laboratory. Basic component for the Temperature Control System is LM-741 type of Operation Amplifier, which is functionalized as summer for voltage comparator. Function test for this Control System shown its ability for damping on temperature reference. The Temperature Control System will be implemented on PCB Processing Machine. (author)

A Highly Thermostable In2O3/ITO Thin Film Thermocouple Prepared via Screen Printing for High Temperature Measurements

Directory of Open Access Journals (Sweden)

Yantao Liu

2018-03-01

Full Text Available An In2O3/ITO thin film thermocouple was prepared via screen printing. Glass additives were added to improve the sintering process and to increase the density of the In2O3/ITO films. The surface and cross-sectional images indicate that both the grain size and densification of the ITO and In2O3 films increased with the increase in annealing time. The thermoelectric voltage of the In2O3/ITO thermocouple was 53.5 mV at 1270 °C at the hot junction. The average Seebeck coefficient of the thermocouple was calculated as 44.5 μV/°C. The drift rate of the In2O3/ITO thermocouple was 5.44 °C/h at a measuring time of 10 h at 1270 °C.

Measuring skin temperature before, during and after exercise: a comparison of thermocouples and infrared thermography

International Nuclear Information System (INIS)

Fernandes, Alex de Andrade; Amorim, Paulo Roberto dos Santos; De Moura, Anselmo Gomes; Moreira, Danilo Gomes; Costa, Carlos Magno Amaral; Marins, João Carlos Bouzas; Brito, Ciro José; Sillero-Quintana, Manuel

2014-01-01

Measuring skin temperature (T SK ) provides important information about the complex thermal control system and could be interesting when carrying out studies about thermoregulation. The most common method to record T SK  involves thermocouples at specific locations; however, the use of infrared thermal imaging (IRT) has increased. The two methods use different physical processes to measure T SK , and each has advantages and disadvantages. Therefore, the objective of this study was to compare the mean skin temperature (MT SK ) measurements using thermocouples and IRT in three different situations: pre-exercise, exercise and post-exercise. Analysis of the residual scores in Bland–Altman plots showed poor agreement between the MT SK  obtained using thermocouples and those using IRT. The averaged error was −0.75 °C during pre-exercise, 1.22 °C during exercise and −1.16 °C during post-exercise, and the reliability between the methods was low in the pre- (ICC = 0.75 [0.12 to 0.93]), during (ICC = 0.49 [−0.80 to 0.85]) and post-exercise (ICC = 0.35 [−1.22 to 0.81] conditions. Thus, there is poor correlation between the values of MT SK  measured by thermocouples and IRT pre-exercise, exercise and post-exercise, and low reliability between the two forms of measurement. (paper)

A rigid fast-response thermometer for atmospheric research

NARCIS (Netherlands)

van Asselt, C.J.; Jacobs, A.F.G.; van Boxel, J.; Jansen, A.E.

1991-01-01

A fast-response temperature sensor for measuring atmospheric temperature was constructed and is described. The sensor was based on the thermocouple principle, connected to a thermocouple conditioner (AD595): the cold junction was compensated via an electrical reference and the signal amplified. This

SMORN-1: thermoelectrically generated noise in sheathed thermocouples and in other low level instrumentation cables

International Nuclear Information System (INIS)

Mathieu, F.; Meier, R.; Soenen, M.; Delcon, M.; Nysten, C.

Starting from the fact that thermoelectric emfs of thermocouples are generated in the thermal gradients and not at the hot junction, it is shown how thermoelectric heterogeneity in conjunction with natural and forced convection phenomena gives rise to unwanted noise called: ''thermoelectric noise'' in the technological sense. A distinction is made between four different types of noise--i.e. uncorrelated noise, correlated noise, spectral noise and thermoelectric noise in the physical sense--each of which has its own characteristics. The experimental results presented reveal that noise amplitudes may be quite embarrassing when dealing with problems of quantitative signal fluctuation analysis. It is however emphasized that thermoelectric noise may also convey useful information which, without noise, might be lost

Experiences with W3Re/W25Re thermocouples in fuel pins of NS Otto Hahn's two cores

International Nuclear Information System (INIS)

Kolb, M.

1975-01-01

Applications and performance of thermocouples in the Otto Hahn reactor are presented. The measurement of effective thermocouple time constants and of fuel rod heat transfer time constants utilizing the reactor noise and the resulting small temperature fluctuations which has become practical by the advent of modern noise analysis systems, is dealt with

Recent improvements on micro-thermocouple based SThM

OpenAIRE

Nguyen, T. P.; Thiery, L.; Teyssieux, D.; Briand, Danick; Vairac, P.

2017-01-01

The scanning thermal microscope (SThM) has become a versatile tool for local surface temperature mapping or measuring thermal properties of solid materials. In this article, we present recent improvements in a SThM system, based on a micro-wire thermocouple probe associated with a quartz tuning fork for contact strength detection. Some results obtained on an electrothermal micro-hotplate device, operated in active and passive modes, allow demonstrating its performance as a coupled force detec...

The influence of lead temperature on the accuracy of various stainless-steel sheathed, mineral-inulated nickel-chromium/nickel aluminium thermocouples

International Nuclear Information System (INIS)

Burnett, P.; Burns, J.S.

1977-10-01

Samples of three types of stainless steel sheathed MI thermocouples, such as are currently used in fire and furnace tests of transport flasks, have been subjected to high lead temperatures whilst the thermojunctions were kept at a constant low temperature. Both the lead temperature and the length of lead at temperature have been varied. As the lead temperature rises from ambient to a selected value, the emf output from the thermocouple initially decreases and then increases, taking up a final value dependent on the particular conditions. Below a threshold lead temperature, no significant steady state error occurs and the negative transient is generally negligible. Each thermocouple has its own threshold temperature, the lowest found being about 600 0 C, although the average lies at about 750 0 C. Above the threshold lead temperature, the thermal emf can be in error by the equivalent of more than 100 0 C, the highest error found being nearly 230 0 C at a temperature 250 0 C above threshold. The same thermocouple showed a negative transient of 13 0 C 3 minutes after start of heating to 890 0 C. It is probable that the steady state error arises because of the degradation of the thermocouple mineral insulation at elevated temperatures and recommendations are made on the use of such thermocouples in fire and furnace tests. The cause of the initial negative transient error has not been identified, but ways of minimising any resultant errors are suggested. (author)

Heated junction thermocouple level measurement apparatus

International Nuclear Information System (INIS)

Bevilacqua, F.; Burger, J.M.

1984-01-01

A liquid level sensing apparatus senses the level of liquid surrounding the apparatus. A plurality of axially spaced sensors are enclosed in a separator tube. The separator tube tends to collapse the level of a two-phase fluid within the separator tube into essentially a liquid phase and a gaseous phase where the collapsed level bears a relationship to the coolant inventory outside the separator tube. The level of the liquid phase is sensed by level sensing apparatus. The separator tube contains inlet-outlet ports near the top and bottom thereof to equalize the liquid level inside and outside the separator tube when the level fluctuates or the water within the separator tube flashes to steam. Each sensor is comprised of a heater, a heated thermocouple junction and an unheated thermocouple junction within an elongated heat conductive housing. The heated portion of housing is enclosed in a splash guard with inlet-outlet ports near the top and bottom to equalize the liquid level inside and outside the splash guardand to eliminate the spurious indications of liquid level change which may arise if water droplets contact the housing in the region of the heater. To prevent steam bubbles entrained in a two-phase fluid cross flow from entering the lateral inlet-outlet ports of the separator tube, the separator tube is enclosed in support tube which may in turn be enclosed in an otherwise unused control element assembly shroud. The lateral inlet-outlet ports of separator tube are axially offset from lateral inlet-outlet ports of support tube at least where support tube is subjected to cross flow. The shroud is open on the bottom and has lateral inlet-outlet ports to facilitate liquid level fluctuations to equalize inside and outside shroud

Proposed algorithm for determining the delta intercept of a thermocouple psychrometer curve

International Nuclear Information System (INIS)

Kurzmack, M.A.

1993-01-01

The USGS Hydrologic Investigations Program is currently developing instrumentation to study the unsaturated zone at Yucca Mountain in Nevada. Surface-based boreholes up to 2,500 feet in depth will be drilled, and then instrumented in order to define the water potential field within the unsaturated zone. Thermocouple psychrometers will be used to monitor the in-situ water potential. An algorithm is proposed for simply and efficiently reducing a six wire thermocouple psychrometer voltage output curve to a single value, the delta intercept. The algorithm identifies a plateau region in the psychrometer curve and extrapolates a linear regression back to the initial start of relaxation. When properly conditioned for the measurements being made, the algorithm results in reasonable results even with incomplete or noisy psychrometer curves over a 1 to 60 bar range

Recent improvements on micro-thermocouple based SThM

Science.gov (United States)

Nguyen, TP; Thiery, L.; Teyssieux, D.; Briand, D.; Vairac, P.

2017-01-01

The scanning thermal microscope (SThM) has become a versatile tool for local surface temperature mapping or measuring thermal properties of solid materials. In this article, we present recent improvements in a SThM system, based on a micro-wire thermocouple probe associated with a quartz tuning fork for contact strength detection. Some results obtained on an electrothermal micro-hotplate device, operated in active and passive modes, allow demonstrating its performance as a coupled force detection and thermal measurement system.

Home-made temperature monitoring system from four-channel K-type thermocouples via internet of thing technology platform

Science.gov (United States)

Detmod, Thitaporn; Özmen, Yiǧiter; Songkaitiwong, Kittiphot; Saenyot, Khanuengchat; Locharoenrat, Kitsakorn; Lekchaum, Sarai

2018-06-01

This paper is aimed to design and construct the home-made temperature monitoring system from four-channel K-type thermocouples in order to improve the temperature measurement based on standard evaluation measurements guidance. The temperature monitoring system was capable to record the temperature on SD card and to display the realtime temperature on Internet of Thing Technology platform. The temperature monitoring system was tested in terms of the temperature measurement accuracy and delay response time. It was found that a standard deviation was acceptable as compared to the Instrument Society of America. The response time of the microcontroller to SD card was 2 sec faster than that of the microcontroller to Thingspeak.

R and D advances in high temperature thermocouples for nuclear utilization in severe environment

International Nuclear Information System (INIS)

Schley, R.; Blanc, J.Y.

1985-01-01

Safety experiments for water reactors in Cadarache have made necessary a research program for developing special thermocopules for use in severe fuel damage conditions (superheated steam). Standard cladding thermocouples (type K, alumina insulated, zircaloy sheathed, O.D. 0.7 mm) must be replaced by others with W3Re versus W25Re legs, Ta sheath protected by a zircaloy outer sheath, and hafnia or thoria insulation. The zircaloy sheath will be sufficient to protect correctly tantalum. Fuel centerline thermocouples have W5Re versus W26Re or W3Re versus W25Re legs, hard-fired thoria insulation and rhenium CVD sheath (O.D. 1.1 mm). A protective ReSi/sub 2/ coating is applied. This protection withstands at least 1600 0 C, 45 minutes in steam. Tests are done concerning: (a) materials compatibilities in helium between 1400 0 C and 2000 0 C, (b) prototypes qualification (In Saclay or Grenoble), (c) determination of errors due to degradation of insulation resistance of thermocouples cables (with magnesia, hafnia, alumina), (d) Ir or Re protective coatings by CVD process, other coatings by ionic bombardment, etc...A completely new type of hot junction has been patented

Thermocouple placement and hot spots in radioactive waste tanks

International Nuclear Information System (INIS)

Barker, J.J.

1991-06-01

Analytical solutions available in Carslaw and Jaeger's Conduction of Heat in Solids for continuous point sources and for continuous finite sources are used to demonstrate that placement of thermocouples on a fine enough grid to detect a hot spot is impracticable for existing waste tanks but fortunately not necessary. Graphs covering ranges of diffusivities, times, temperatures and heat generation rates are included. 2 refs., 8 figs., 5 tabs

Tile Surface Thermocouple Measurement Challenges from the Orbiter Boundary Layer Transition Flight Experiment

Science.gov (United States)

Campbell, Charles H.; Berger, Karen; Anderson, Brian

2012-01-01

Hypersonic entry flight testing motivated by efforts seeking to characterize boundary layer transition on the Space Shuttle Orbiters have identified challenges in our ability to acquire high quality quantitative surface temperature measurements versus time. Five missions near the end of the Space Shuttle Program implemented a tile surface protuberance as a boundary layer trip together with tile surface thermocouples to capture temperature measurements during entry. Similar engineering implementations of these measurements on Discovery and Endeavor demonstrated unexpected measurement voltage response during the high heating portion of the entry trajectory. An assessment has been performed to characterize possible causes of the issues experienced during STS-119, STS-128, STS-131, STS-133 and STS-134 as well as similar issues encountered during other orbiter entries.

Instrument response during overpower transients at TREAT

International Nuclear Information System (INIS)

Meek, C.C.; Bauer, T.H.; Hill, D.J.; Froehle, P.H.; Klickman, A.E.; Tylka, J.P.; Doerner, R.C.; Wright, A.E.

1982-01-01

A program to empirically analyze data residuals or noise to determine instrument response that occurs during in-pile transient tests is out-lined. As an example, thermocouple response in the Mark III loop during a severe overpower transient in TREAT is studied both in frequency space and in real-time. Time intervals studied included both constant power and burst portions of the power transient. Thermocouple time constants were computed. Benefits and limitations of the method are discussed

Attachment of Free Filament Thermocouples for Temperature Measurements on Ceramic Matrix Composites

Science.gov (United States)

Lei, Jih-Fen; Cuy, Michael D.; Wnuk, Stephen P.

1998-01-01

At the NASA Lewis Research Center, a new installation technique utilizing convoluted wire thermocouples (TC's) was developed and proven to produce very good adhesion on CMC's, even in a burner rig environment. Because of their unique convoluted design, such TC's of various types and sizes adhere to flat or curved CMC specimens with no sign of delamination, open circuits, or interactions-even after testing in a Mach 0.3 burner rig to 1200 C (2200 F) for several thermal cycles and at several hours at high temperatures. Large differences in thermal expansion between metal thermocouples and low-expansion materials, such as CMC's, normally generate large stresses in the wires. These stresses cause straight wires to detach, but convoluted wires that are bonded with strips of coating allow bending in the unbonded portion to relieve these expansion stresses.

AGR-1 Thermocouple Data Analysis

International Nuclear Information System (INIS)

Einerson, Jeff

2012-01-01

This report documents an effort to analyze measured and simulated data obtained in the Advanced Gas Reactor (AGR) fuel irradiation test program conducted in the INL's Advanced Test Reactor (ATR) to support the Next Generation Nuclear Plant (NGNP) R and D program. The work follows up on a previous study (Pham and Einerson, 2010), in which statistical analysis methods were applied for AGR-1 thermocouple data qualification. The present work exercises the idea that, while recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, results of the numerical simulations can be used in combination with the statistical analysis methods to further improve qualification of measured data. Additionally, the combined analysis of measured and simulation data can generate insights about simulation model uncertainty that can be useful for model improvement. This report also describes an experimental control procedure to maintain fuel target temperature in the future AGR tests using regression relationships that include simulation results. The report is organized into four chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program, AGR-1 test configuration and test procedure, overview of AGR-1 measured data, and overview of physics and thermal simulation, including modeling assumptions and uncertainties. A brief summary of statistical analysis methods developed in (Pham and Einerson 2010) for AGR-1 measured data qualification within NGNP Data Management and Analysis System (NDMAS) is also included for completeness. Chapters 2-3 describe and discuss cases, in which the combined use of experimental and simulation data is realized. A set of issues associated with measurement and modeling uncertainties resulted from the combined analysis are identified. This includes demonstration that such a combined analysis led to important insights for reducing uncertainty in presentation of AGR-1 measured data (Chapter 2) and interpretation of

AGR-1 Thermocouple Data Analysis

Energy Technology Data Exchange (ETDEWEB)

Jeff Einerson

2012-05-01

This report documents an effort to analyze measured and simulated data obtained in the Advanced Gas Reactor (AGR) fuel irradiation test program conducted in the INL's Advanced Test Reactor (ATR) to support the Next Generation Nuclear Plant (NGNP) R&D program. The work follows up on a previous study (Pham and Einerson, 2010), in which statistical analysis methods were applied for AGR-1 thermocouple data qualification. The present work exercises the idea that, while recognizing uncertainties inherent in physics and thermal simulations of the AGR-1 test, results of the numerical simulations can be used in combination with the statistical analysis methods to further improve qualification of measured data. Additionally, the combined analysis of measured and simulation data can generate insights about simulation model uncertainty that can be useful for model improvement. This report also describes an experimental control procedure to maintain fuel target temperature in the future AGR tests using regression relationships that include simulation results. The report is organized into four chapters. Chapter 1 introduces the AGR Fuel Development and Qualification program, AGR-1 test configuration and test procedure, overview of AGR-1 measured data, and overview of physics and thermal simulation, including modeling assumptions and uncertainties. A brief summary of statistical analysis methods developed in (Pham and Einerson 2010) for AGR-1 measured data qualification within NGNP Data Management and Analysis System (NDMAS) is also included for completeness. Chapters 2-3 describe and discuss cases, in which the combined use of experimental and simulation data is realized. A set of issues associated with measurement and modeling uncertainties resulted from the combined analysis are identified. This includes demonstration that such a combined analysis led to important insights for reducing uncertainty in presentation of AGR-1 measured data (Chapter 2) and interpretation of

Experience with W3Re/W25Re thermocouples in fuel pins of NS Otto Hahn's two cores

International Nuclear Information System (INIS)

Kolb, M.

1976-01-01

The paper first deals with the installation of 18 and 9 high-temperature sheathed thermocouples in fuel rods of the cores FDR-1 and FDR-2, respectively. The measured fuel rod centerline temperatures could be related to the local linear rod power at any given time by means of the densities of fission products with different half-lives obtained from fuel rod γ-scans. The fuel temperatures show then already an increase with the burn-up of the FDR-1 which becomes steeper when taking into account the decrease of the EMF measured at irradiated thermocouples taken from the fuel rods. Finally, the determination of effective thermocouple time constants and of fuel rod heat transfer time constants is demonstrated by utilizing the reactor noise to measure the transfer function between neutron flux and fuel temperature signal. (orig.) [de

Recommendations for the specification of thermocouples for nuclear applications

International Nuclear Information System (INIS)

1977-05-01

This Code of Practice is a guide for use in the preparation of individual specifications to cover, as fully as possible the conditions governing the supply of raw materials and the ordering, manufacture, testing, inspection, handling and installation of thermocouples for use in nuclear environments in order that reliable, consistent and generally acceptable results can be obtained. The insulation resistance values quoted in this document apply to magnesium oxide. If other insulants are called for, appropriate values must be specified. (author)

Use of indexed sensitivity factors in the analysis of nickel and iron based alloys: study of the decalibration of sheathed Chromel/Alumel thermocouples

International Nuclear Information System (INIS)

Christie, W.H.

1978-01-01

Sheathed Chromel versus Alumel thermocouples decalibrate when exposed to temperatures in excess of 1100 0 C. Thermocouples sheathed in Inconel-600 and type 304 stainless steel were studied in this work. Quantified SIMS data showed that the observed decalibrations were due to significant alterations that took place in the Chromel and Alumel thermoelements. The amount of alteration was different for each thermocouple and was influenced by the particular sheath material used in the thermocouple construction. Relative sensitivity factors, indexed by a matrix ion species ratio, were used to quantify SIMS data for three nickel-based alloys, Chromel, Alumel, and Inconel-600, and an iron-based alloy, type 304 stainless steel. Oxygen pressure >2 x 10 -6 torr in the sputtering region gave enhanced sensitivity and superior quantitative results as compared to data obtained at instrumental residual pressure

Computer subroutines to aid analysis of experimental data from thermocouples and pressure transducers

International Nuclear Information System (INIS)

Durham, M.E.

1976-08-01

Three subroutines (CALSET, CALBR8 and PTRCAL) have been written to provide a convenient system for converting experimental measurements obtained from thermocouples and pressure transducers to temperatures and pressures. The method of operation and the application of the subroutines are described. (author)

Experimental measurement of the interfacial heat transfer coefficients of subcooled flow boiling using micro-thermocouple and double directional images

International Nuclear Information System (INIS)

Seong-Jin Kim; Goon-Cherl Park

2005-01-01

Full text of publication follows: Models or correlations for phase interface are needed to analyze the multi-phase flow. Interfacial heat transfer coefficients are important to constitute energy equation of multi-phase flow, specially. In subcooled boiling flow, bubble condensation at the bubble-liquid interface is a major mechanism of heat transfer within bulk subcooled liquid. Bubble collapse rates and temperatures of each phase are needed to determine the interfacial heat transfer coefficient for bubble condensation. Bubble collapse rates were calculated through image processing in single direction, generally. And in case of liquid bulk temperature, which has been obtained by general temperature sensor such as thermocouple, was used. However, multi-directional images are needed to analyze images due to limitations of single directional image processing. Also, temperature sensor, which has a fast response time, must be used to obtain more accurate interfacial heat transfer coefficient. Low pressure subcooled water flow experiments using micro-thermocouple and double directional image processing with mirrors were conducted to investigate bubble condensation phenomena and to modify interfacial heat transfer correlation. Experiments were performed in a vertical subcooled boiling flow of a rectangular channel. Bubble condensing traces with respect to time were recorded by high speed camera in double direction and bubble collapse rates were calculated by processing recorded digital images. Temperatures were measured by micro-thermocouple, which is a K-type with a 12.7 μm diameter. The liquid temperature was estimated by the developed algorithm to discriminate phases and find each phase temperature in the measured temperature including both liquid and bubble temperature. The interfacial heat transfer coefficient for bubble condensation was calculated from the bubble collapse rates and the estimated liquid temperature, and its correlation was modified. The modified

Response Mixture Modeling: Accounting for Heterogeneity in Item Characteristics across Response Times.

Science.gov (United States)

Molenaar, Dylan; de Boeck, Paul

2018-06-01

In item response theory modeling of responses and response times, it is commonly assumed that the item responses have the same characteristics across the response times. However, heterogeneity might arise in the data if subjects resort to different response processes when solving the test items. These differences may be within-subject effects, that is, a subject might use a certain process on some of the items and a different process with different item characteristics on the other items. If the probability of using one process over the other process depends on the subject's response time, within-subject heterogeneity of the item characteristics across the response times arises. In this paper, the method of response mixture modeling is presented to account for such heterogeneity. Contrary to traditional mixture modeling where the full response vectors are classified, response mixture modeling involves classification of the individual elements in the response vector. In a simulation study, the response mixture model is shown to be viable in terms of parameter recovery. In addition, the response mixture model is applied to a real dataset to illustrate its use in investigating within-subject heterogeneity in the item characteristics across response times.

Detection of thermocouple malfunction in the Beacon system

International Nuclear Information System (INIS)

Morita, T.; Heibel, M.D.; Congedo, T.V.

1992-01-01

The BEACON system uses Core Exit Thermocouples (T/C) extensively for continuous radial power distribution monitoring. The T/C's are used to adjust the reference power distribution generated by the BEACON system to match the current radial power distribution. T/C reliability, repeatability, and relative accuracy have been very satisfactory. However, it is very important to detect any T/C malfunctions during operation, since a T/C signal change caused by an undetected malfunction can lead to serious errors in the radial power distribution developed by BEACON. A simple procedure has been developed which is capable of discriminating between changes in T/C signals caused by actual changes in reactor conditions and signal changes caused by T/C malfunctions

New fixed-point mini-cell to investigate thermocouple drift in a high-temperature environment under neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Laurie, M.; Vlahovic, L.; Rondinella, V.V. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe, (Germany); Sadli, M.; Failleau, G. [Laboratoire Commun de Metrologie, LNE-Cnam, Saint-Denis, (France); Fuetterer, M.; Lapetite, J.M. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten, (Netherlands); Fourrez, S. [Thermocoax, 8 rue du pre neuf, F-61100 St Georges des Groseillers, (France)

2015-07-01

Temperature measurements in the nuclear field require a high degree of reliability and accuracy. Despite their sheathed form, thermocouples subjected to nuclear radiations undergo changes due to radiation damage and transmutation that lead to significant EMF drift during long-term fuel irradiation experiment. For the purpose of a High Temperature Reactor fuel irradiation to take place in the High Flux Reactor Petten, a dedicated fixed-point cell was jointly developed by LNE-Cnam and JRC-IET. The developed cell to be housed in the irradiation rig was tailor made to quantify the thermocouple drift during the irradiation (about two year duration) and withstand high temperature (in the range 950 deg. C - 1100 deg. C) in the presence of contaminated helium in a graphite environment. Considering the different levels of temperature achieved in the irradiation facility and the large palette of thermocouple types aimed at surveying the HTR fuel pebble during the qualification test both copper (1084.62 deg. C) and gold (1064.18 deg. C) fixed-point materials were considered. The aim of this paper is to first describe the fixed-point mini-cell designed to be embedded in the reactor rig and to discuss the preliminary results achieved during some out of pile tests as much as some robustness tests representative of the reactor scram scenarios. (authors)

External attachment of titanium sheathed thermocouples to zirconium nuclear fuel rods for the LOFT reactor

International Nuclear Information System (INIS)

Welty, R.K.

1980-01-01

The Exxon Nuclear Company, Inc., acting as a Subcontractor to EG and G Idaho Inc., Idaho National Engineering Laboratory, Idaho Falls, Idaho, has developed a welding process to attach titanium sheathed thermocouples to the outside of the zircaloy clad fuel rods. The fuel rods and thermocouples are used to test simulated loss-of-coolant accident (LOCA) conditions in a pressurized water reactor (LOFT Reactor, Idaho National Laboratory). A laser beam was selected as the optimum welding process because of the extremely high energy input per unit volume that can be achieved allowing local fusion of a small area irrespective of the difference in material thickness to be joined. A commercial pulsed laser and energy control system was installed along with specialized welding fixtures. Laser room facility requirements and tolerances were established. Performance qualifications, and detailed welding procedures were also developed. Product performance tests were conducted to assure that engineering design requirements could be met on a production basis

Characteristics of self-powered neutron detectors used in power reactors

International Nuclear Information System (INIS)

Todt, W.H.

1997-01-01

Self-Powered Neutron Detectors have been used effectively as in-core flux monitors for over twenty-five years in nuclear power reactors world-wide. The basic properties of these radiation sensors are described including their nuclear, electrical and mechanical characteristics. Recommendations are given for the proper choice of the self-powered detector emitter to provide the proper response time and radiation sensitivity desired for use in an effective in-core radiation monitoring system. Examples are shown of specific self-powered detector designs which are being effectively used in in-core instrumentation systems for pressurised water, heavy water and graphite moderated light water reactors. Examples are also shown of the mechanical configurations of in-core assemblies of self-powered detectors combined with in-core thermocouples presently used in pressurised water and heavy water reactors worldwide. This paper is a summary of a new IEC standard to be issued in 1996 describing the characteristics and test methods of self-powered detectors used in nuclear power reactors. (author)

Elastic-plastic response characteristics during frequency nonstationary waves

International Nuclear Information System (INIS)

Miyama, T.; Kanda, J.; Iwasaki, R.; Sunohara, H.

1987-01-01

The purpose of this paper is to study fundamental effects of the frequency nonstationarity on the inelastic responses. First, the inelastic response characteristics are examined by applying stationary waves. Then simple representation of nonstationary characteristics is considered to general nonstationary input. The effects for frequency nonstationary response are summarized for inelastic systems. The inelastic response characteristics under white noise and simple frequency nonstationary wave were investigated, and conclusions can be summarized as follows. 1) The maximum response values for both BL model and OO model corresponds fairly well with those estimated from the energy constant law, even when R is small. For the OO model, the maximum displacement response forms a unique curve except for very small R. 2) The plastic deformation for the BL model is affected by wide frequency components, as R decreases. The plastic deformation for the OO model can be determined from the last stiffness. 3). The inelastic response of the BL model is considerably affected by the frequency nonstationarity of the input motion, while the response is less affected by the nonstationarity for OO model. (orig./HP)

The Combined Use of a Gas-Controlled Heat Pipe and a Copper Point to Improve the Calibration of Thermocouples up to 1100 ˚C

Science.gov (United States)

Astrua, M.; Iacomini, L.; Battuello, M.

2008-10-01

The calibration of platinum-based thermocouples from 420 °C to 1,100 ˚C is currently carried out at INRIM making use of two different apparatus: for temperatures below 930 ˚C, a potassium gas-controlled heat pipe (GCHP) is used, whereas a metal-block furnace is adopted for higher temperatures. The standard uncertainty of the reference temperature obtained in the lower temperature range is almost one order of magnitude better than in the higher temperature range. A sealed copper cell was investigated to see if it could be used to calibrate thermocouples above 930 ˚C with a lower uncertainty than our current procedures allowed. The cell was characterized with Type S and Pt/Pd thermocouples and with an HTPRT. The freezing plateaux were flat within 0.01 ˚C and lasted up to 1 h with a repeatability of 0.02 ˚C. The temperature of the cell was determined with a standard uncertainty of 0.04 ˚C. Hence, the copper cell was found to be superior to the comparator furnace for the calibration of platinum-based thermocouples because of the significant decrease in the uncertainty that it provides. An analysis was also carried out on the calibration of Pt/Pd thermocouples, and it was found that the combined use of the potassium GCHP and the Cu fixed-point cell is adequate to exploit the potential of these sensors in the range from 420 °C to 1,084 °C. A comparison with a fixed-point calibration was also made which gave rise to agreement within 0.07 ˚C between the two approaches.

A Simple Test to Evaluate the Calibration Stability and Accuracy of Infrared Thermocouple Sensors

OpenAIRE

Pinnock, Derek R.; Bugbee, Bruce

2002-01-01

Accurately measuring surface temperature is not difficult when the surface, the sensor, and air temperatures are similar, but it is challenging when the surface temperature is significantly different than air and sensor temperatures. We tested three Infrared Thermocouple sensors (IRT’s) that had been used for two years in a greenhouse environment. The importance of the correction for sensor body temperature was also examined.

An Explicit Approach Toward Modeling Thermo-Coupled Deformation Behaviors of SMPs

Directory of Open Access Journals (Sweden)

Hao Li

2017-03-01

Full Text Available A new elastoplastic J 2 -flow models with thermal effects is proposed toward simulating thermo-coupled finite deformation behaviors of shape memory polymers. In this new model, an elastic potential evolving with development of plastic flow is incorporated to characterize the stress-softening effect at unloading and, moreover, thermo-induced plastic flow is introduced to represent the strain recovery effect at heating. It is shown that any given test data for both effects may be accurately simulated by means of direct and explicit procedures. Numerical examples for model predictions compare well with test data in literature.

Characteristics of self-powered neutron detectors used in power reactors

International Nuclear Information System (INIS)

Todt, William H. Sr.

1998-01-01

Self-powered neutron detectors have been used effectively as in-core flux monitors for over twenty-five years in nuclear power reactors worldwide. This paper describes the basic properties of these radiation sensors including their nuclear, electrical and mechanical characteristics. Recommendations are given for the proper choice of the self-powered detector emitter to provide the proper response time and radiation sensitivity desired for use in an effective in-core radiation monitoring system. Examples are shown of specific self-powered detector designs, which are being effectively, used in in-core instrumentation systems for pressurized water, heavy water and graphite moderated light water reactors. Also examples are shown of the mechanical configurations of in-core assemblies of self-powered detectors combined with in-core thermocouples presently used in pressurized water and heavy water reactors worldwide. (author)

Development of Mechanical Sealing and Laser Welding Technology to Instrument Thermocouple for Nuclear Fuel Test Rod

Energy Technology Data Exchange (ETDEWEB)

Joung, Chang-Young; Ahn, Sung-Ho; Hong, Jin-Tae; Kim, Ka-Hye; Huh, Sung-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Zircaloy-4 of the nuclear fuel test rod, AISI 316L of the mechanical sealing parts, and the MI (mineral insulated) cable at a thermocouple instrumentation are hetero-metals, and are difficult to weld to dissimilar materials. Therefore, a mechanical sealing method to instrument the thermocouple should be conducted using two kinds of sealing process as follows: One is a mechanical sealing process using Swagelok, which is composed of sealing components that consists of an end-cap, a seal tube, a compression ring and a Swagelok nut. The other is a laser welding process used to join a seal tube, and an MI cable, which are made of the same material. The mechanical sealing process should be sealed up with the mechanical contact compressed by the strength forced between a seal tube and an end-cap, and the laser welding process should be conducted to have no defects on the sealing area between a seal tube and an MI cable. Therefore, the mechanical sealing and laser welding techniques need to be developed to accurately measure the centerline temperature of the nuclear fuel test rod in an experimental reactor. The mechanical sealing and laser welding tests were conducted to develop the thermocouple instrumentation techniques for the nuclear fuel test rod. The optimum torque value of a Swagelok nut to seal the mechanical sealing part between the end-cap and seal tube was established through various torque tests using a torque wrench. The optimum laser welding conditions to seal the welding part between a seal tube and an MI cable were obtained through various welding tests using a laser welding system.

Development of Mechanical Sealing and Laser Welding Technology to Instrument Thermocouple for Nuclear Fuel Test Rod

International Nuclear Information System (INIS)

Joung, Chang-Young; Ahn, Sung-Ho; Hong, Jin-Tae; Kim, Ka-Hye; Huh, Sung-Ho

2015-01-01

Zircaloy-4 of the nuclear fuel test rod, AISI 316L of the mechanical sealing parts, and the MI (mineral insulated) cable at a thermocouple instrumentation are hetero-metals, and are difficult to weld to dissimilar materials. Therefore, a mechanical sealing method to instrument the thermocouple should be conducted using two kinds of sealing process as follows: One is a mechanical sealing process using Swagelok, which is composed of sealing components that consists of an end-cap, a seal tube, a compression ring and a Swagelok nut. The other is a laser welding process used to join a seal tube, and an MI cable, which are made of the same material. The mechanical sealing process should be sealed up with the mechanical contact compressed by the strength forced between a seal tube and an end-cap, and the laser welding process should be conducted to have no defects on the sealing area between a seal tube and an MI cable. Therefore, the mechanical sealing and laser welding techniques need to be developed to accurately measure the centerline temperature of the nuclear fuel test rod in an experimental reactor. The mechanical sealing and laser welding tests were conducted to develop the thermocouple instrumentation techniques for the nuclear fuel test rod. The optimum torque value of a Swagelok nut to seal the mechanical sealing part between the end-cap and seal tube was established through various torque tests using a torque wrench. The optimum laser welding conditions to seal the welding part between a seal tube and an MI cable were obtained through various welding tests using a laser welding system

External attachment of titanium sheathed thermocouples to zirconium nuclear fuel rods for the loss-of-fluid-test (LOFT) Reactor

International Nuclear Information System (INIS)

Welty, R.K.

1980-01-01

A welding process to attach titanium sheathed thermocouples to the outside of the zircaloy clad fuel rods has been developed. A laser beam was selected as the optimum welding process because of the extremely high energy input per unit volume that can be achieved allowing local fusion of a small area irrespective of the difference in material thickness to be joined. Irradiation tests showed no degradation of thermocouples or weld structure. Fast thermal cycle and heater rod blowdown reflood tests were made to subject the weldments to high temperatures, high pressure steam, and fast water quench cycles. From the behavior of these tests, it was concluded that the attachment welds would survive a series of reactor safety tests. 2 refs

Nuclear Power Plant Thermocouple Sensor-Fault Detection and Classification Using Deep Learning and Generalized Likelihood Ratio Test

Science.gov (United States)

Mandal, Shyamapada; Santhi, B.; Sridhar, S.; Vinolia, K.; Swaminathan, P.

2017-06-01

In this paper, an online fault detection and classification method is proposed for thermocouples used in nuclear power plants. In the proposed method, the fault data are detected by the classification method, which classifies the fault data from the normal data. Deep belief network (DBN), a technique for deep learning, is applied to classify the fault data. The DBN has a multilayer feature extraction scheme, which is highly sensitive to a small variation of data. Since the classification method is unable to detect the faulty sensor; therefore, a technique is proposed to identify the faulty sensor from the fault data. Finally, the composite statistical hypothesis test, namely generalized likelihood ratio test, is applied to compute the fault pattern of the faulty sensor signal based on the magnitude of the fault. The performance of the proposed method is validated by field data obtained from thermocouple sensors of the fast breeder test reactor.

Design and research of seal structure for thermocouple column assembly

International Nuclear Information System (INIS)

Rao Qiqi; Li Na; Zhao Wei; Ma Zhigang

2015-01-01

The new seal structure was designed to satisfy the function of thermocouple column assembly and the reactor structure. This seal structure uses the packing graphite ring and adopts the self-sealing principle. Cone angle is brought to the seal face of seal structure which is conveniently to assembly and disassembly. After the sealing principle analysis and stress calculation of graphite ring which adopt the cone angle, the cone angle increases the radial force of seal structure and improves the seal effect. The stress analysis result shows the seal structure strength satisfies the regulation requirement. The cold and hot function test results shows the sealing effect is good, and the design requirement is satisfied. (authors)

LOFT ECC Pitot Tube and Thermocouple Rake Penetration thermal analysis

International Nuclear Information System (INIS)

Tolan, B.J.

1977-01-01

A thermal analysis of the LOFT ECC Pitot Tube and Thermocouple Rake Penetration was performed using COUPLE, a two-dimensional finite element computer code. Four transients which conservatively cover all transients the rake will be exposed to were included in this analysis in order to comply with the ASME Code Section III requirements. The transients conservatively cover hot and cold leg operation, and nuclear and nonnuclear operation. The four transients include the LOCE with ECC injection transient, the single control rod drop transient, the scram transient, and the heatup with 0 to 100% load change transient. Temperature distributions in the rake were obtained for each of the four transients and several plots of node temperatures vs. time are given

Study for on-line system to identify inadvertent control rod drops in PWR reactors using ex-core detector and thermocouple measures

International Nuclear Information System (INIS)

Souza, Thiago J.; Medeiros, Jose A.C.C.; Goncalves, Alessandro C.

2015-01-01

Accidental control rod drops event in PWR reactors leads to an unsafe operating condition. It is important to quickly identify the rod to minimize undesirable effects in such a scenario. In this event, there is a distortion in the power distribution and temperature in the reactor core. The goal of this study is to develop an on-line model to identify the inadvertent control rod dropped in PWR reactor. The proposed model is based on physical correlations and pattern recognition of ex-core detector responses and thermocouples measures. The results of the study demonstrated the feasibility of an on-line system, contributing to safer operation conditions and preventing undesirable effects, as its shutdown. (author)

Study for on-line system to identify inadvertent control rod drops in PWR reactors using ex-core detector and thermocouple measures

Energy Technology Data Exchange (ETDEWEB)

Souza, Thiago J.; Medeiros, Jose A.C.C.; Goncalves, Alessandro C., E-mail: tsouza@nuclear.ufrj.br, E-mail: canedo@lmp.ufrj.br, E-mail: alessandro@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

2015-07-01

Accidental control rod drops event in PWR reactors leads to an unsafe operating condition. It is important to quickly identify the rod to minimize undesirable effects in such a scenario. In this event, there is a distortion in the power distribution and temperature in the reactor core. The goal of this study is to develop an on-line model to identify the inadvertent control rod dropped in PWR reactor. The proposed model is based on physical correlations and pattern recognition of ex-core detector responses and thermocouples measures. The results of the study demonstrated the feasibility of an on-line system, contributing to safer operation conditions and preventing undesirable effects, as its shutdown. (author)

Internal attachment of laser beam welded stainless steel sheathed thermocouples into stainless steel upper end caps in nuclear fuel rods for the LOFT Reactor

International Nuclear Information System (INIS)

Welty, R.K.; Reid, R.D.

1980-01-01

The Exxon Nuclear Company, Inc., acting as a subcontractor to EG and G Idaho Inc., Idaho National Engineering Laboratory, Idaho Falls, Idaho, conducted a laser beam welding study to attach internal stainless steel thermocouples into stainless steel upper end caps in nuclear fuel rods. The objective of this study was to determine the feasibility of laser welding a single 0.063 inch diameter stainless steel (304) sheathed thermocouple into a stainless steel (316) upper end cap for nuclear fuel rods. A laser beam was selected because of the extremely high energy input in unit volume that can be achieved allowing local fusion of a small area irrespective of the difference in material thickness to be joined. A special weld fixture was designed and fabricated to hold the end cap and the thermocouple with angular and rotational adjustment under the laser beam. A commercial pulsed laser and energy control system was used to make the welds

Investigating Microbial Habitats in Hydrothermal Chimneys using Ti-Thermocouple Arrays: Microbial Diversity

Science.gov (United States)

Pagé, A.; Tivey, M. K.; Stakes, D. S.; Bradley, A. M.; Seewald, J. S.; Wheat, C. G.; Reysenbach, A.

2004-12-01

In order to examine the changes that occur in the microbial community composition as a deep-sea hydrothermal vent chimney develops, we deployed Ti-thermocouple arrays over high temperature vents at two active sites of the Guaymas Basin Southern Trough. Chimney material that precipitated around the arrays was recovered after 4 and 72 days. Chimney material that precipitated prior to deployment of the arrays was also recovered at one of the sites (Busted Shroom). Culture-independent analysis based on the small subunit rRNA sequence (cloning and DGGE) was used to determine the microbial diversity associated with subsamples of each chimney. The original Busted Shroom chimney (BSO) was dominated by members of the Crenarchaeota Marine Group I, a group of cosmopolitan marine Archaea, ɛ -Proteobacteria, and γ -Proteobacteria, two divisions of Bacteria that are common to deep-sea vents. The 4 days old Busted Shroom chimney (BSD1) was dominated by members of the Methanocaldococcaceae, hyperthermophilic methanogens, and the 72 days old chimney (BSD2) by members of the Methanosarcinaceae, mesophilic and thermophilic methanogens. At the second site, Toadstool, the 72 days old chimney material that had precipitated around the array (TS) revealed the dominance of sequences from uncultured marine Archaea, the DHVE group I and II, and from the ɛ -Proteobacteria. Additionally, sequences belonging to the Methanocaldococcaceae and Desulfurococcaceae were recovered next to thermocouples that were at temperatures of 109° C (at Busted Shroom) and 116° C (at Toadstool), respectively. These temperatures are higher than the upper limit for growth of cultured representatives from each family.

Low-noise audio amplifiers and preamplifier for use with intrinsic thermocouples

International Nuclear Information System (INIS)

Langner, G.C.; Sachs, R.D.; Stewart, F.L.

1979-03-01

Two simple, low-noise audio amplifiers and one low-noise preamplifier for use with intrinsic thermocouples were designed, built, and tested. The amplifiers and the preamplifier have different front end designs. One amplifier uses ultralow-noise operational amplifiers; the other amplifier uses a hybrid component. The preamplifier uses ultralow-noise discrete components. The amplifiers' equivalent noise inputs, at maximum gain, are 4.09 nV and 50 nV; the preamplifier's input is 4.05 μV. Their bandwidths are 15 600 Hz, 550 Hz, and 174 kHz, respectively. the amplifiers' equivalent noise inputs were measured from approx. 0 to 100 Hz, whereas the preamplifier's equivalent noise input was measured from approx. 0 to 174 kHz

Field installed brazed thermocouple feedthroughs for high vacuum experiments

International Nuclear Information System (INIS)

Anderson, P.; Messick, C.

1983-01-01

In order to reduce the occurrence of vacuum leaks and to increase the availability of the DIII vacuum vessel for experimental operation, effort was applied to developing a vacuum-tight brazed feedthrough system for sheathed thermocouples, stainless steel sheathed conductor cables and tubes for cooling fluids. This brazed technique is a replacement for elastomer ''O'' ring sealed feedthroughs that have proven vulnerable to leaks caused by thermal cycling, etc. To date, about 200 feedthroughs have been used. Up to 91 were grouped on a single conflat flange mounted in a bulkhead connector configuration which facilitates installation and removal. Investigation was required to select a suitable braze alloy, flux and installation procedure. Braze alloy selection was challenging since the alloy was required to have: 1) Melting temperature in excess of the 250 0 C (482 0 F) bakeout temperature. 2) No high vapor pressure elements. 3) Good wetting properties when used in air with acceptable flux. 4) Good wettability to 300 series stainless steel and inconel

W-1 Sodium Loop Safety Facility experiment centerline fuel thermocouple performance

International Nuclear Information System (INIS)

Meyers, S.C.; Henderson, J.M.

1980-05-01

The W-1 Sodium Loop Safety Facility (SLSF) experiment is the fifth in a series of experiments sponsored by the Department of Energy (DOE) as part of the National Fast Breeder Reactor (FBR) Safety Assurance Program. The experiments are being conducted under the direction of Argonne National Laboratory (ANL) and Hanford Engineering Development Laboratory (HEDL). The irradiation phase of the W-1 SLSF experiment was conducted between May 27 and July 20, 1979, and terminated with incipient fuel pin cladding failure during the final boiling transient. Experimental hardware and facility performed as designed, allowing completion of all planned tests and test objectives. This paper focuses on high temperature in-fuel thermocouples and discusses their development, fabrication, and performance in the W-1 experiment

Co-C and Pd-C Eutectic Fixed Points for Radiation Thermometry and Thermocouple Thermometry

Science.gov (United States)

Wang, L.

2017-12-01

Two Co-C and Pd-C eutectic fixed point cells for both radiation thermometry and thermocouple thermometry were constructed at NMC. This paper describes details of the cell design, materials used, and fabrication of the cells. The melting curves of the Co-C and Pd-C cells were measured with a reference radiation thermometer realized in both a single-zone furnace and a three-zone furnace in order to investigate furnace effect. The transition temperatures in terms of ITS-90 were determined to be 1324.18 {°}C and 1491.61 {°}C with the corresponding combined standard uncertainty of 0.44 {°}C and 0.31 {°}C for Co-C and Pd-C, respectively, taking into account of the differences of two different types of furnaces used. The determined ITS-90 temperatures are also compared with that of INRIM cells obtained using the same reference radiation thermometer and the same furnaces with the same settings during a previous bilateral comparison exercise (Battuello et al. in Int J Thermophys 35:535-546, 2014). The agreements are within k=1 uncertainty for Co-C cell and k = 2 uncertainty for Pd-C cell. Shapes of the plateaus of NMC cells and INRIM cells are compared too and furnace effects are analyzed as well. The melting curves of the Co-C and Pd-C cells realized in the single-zone furnace are also measured by a Pt/Pd thermocouple, and the preliminary results are presented as well.

Investigation of pool boiling dynamics on a rectangular heater using nano-thermocouples: is it chaotic or stochastic?

Energy Technology Data Exchange (ETDEWEB)

Sathyamurthi, Vijaykumar; Banerjee, Debjyoti [Texas A and M University, College Station, TX (United States). Dept. of Mechanical Engineering], e-mail: dbanerjee@tamu.edu

2009-07-01

The non-linear dynamical model of pool boiling on a horizontal rectangular heater is assessed from experimental results in this study. Pool boiling experiments are conducted over a horizontal rectangular silicon substrate measuring 63 mm x 35 mm with PF-5060 as the test fluid. Novel nano-thermocouples, micro-machined in-situ on the silicon substrate are used to measure the surface temperature fluctuations for steady state pool boiling. The acquisition frequency for temperature data from the nano-thermocouples is 1 k Hz. The surface temperature fluctuations are analyzed using the TISEAN{sup c} package. A time-delay embedding is employed to generate higher dimensional phase-space vectors from the temperature time series record. The optimal delay is determined from the first minimum of the mutual information function. Techniques such as recurrence plots, and false nearest neighbors tests are employed to assess the presence of deterministic chaotic dynamics. Chaos quantifiers such as correlation dimensions are found for various pool boiling regimes using the raw data as well as noise-reduced data. Additionally, pseudo-phase spaces are used to reconstruct the 'attractors'. The results after non-linear noise reduction shows definitive presence of low-dimensional (d {<=} 7) chaos in fully developed nucleate boiling, at critical heat flux and in film boiling. (author)

Investigation of pool boiling dynamics on a rectangular heater using nano-thermocouples: is it chaotic or stochastic?

International Nuclear Information System (INIS)

Sathyamurthi, Vijaykumar; Banerjee, Debjyoti

2009-01-01

The non-linear dynamical model of pool boiling on a horizontal rectangular heater is assessed from experimental results in this study. Pool boiling experiments are conducted over a horizontal rectangular silicon substrate measuring 63 mm x 35 mm with PF-5060 as the test fluid. Novel nano-thermocouples, micro-machined in-situ on the silicon substrate are used to measure the surface temperature fluctuations for steady state pool boiling. The acquisition frequency for temperature data from the nano-thermocouples is 1 k Hz. The surface temperature fluctuations are analyzed using the TISEAN c package. A time-delay embedding is employed to generate higher dimensional phase-space vectors from the temperature time series record. The optimal delay is determined from the first minimum of the mutual information function. Techniques such as recurrence plots, and false nearest neighbors tests are employed to assess the presence of deterministic chaotic dynamics. Chaos quantifiers such as correlation dimensions are found for various pool boiling regimes using the raw data as well as noise-reduced data. Additionally, pseudo-phase spaces are used to reconstruct the 'attractors'. The results after non-linear noise reduction shows definitive presence of low-dimensional (d ≤ 7) chaos in fully developed nucleate boiling, at critical heat flux and in film boiling. (author)

Boiling detection using signals of self-powered neutron detectors and thermocouples

International Nuclear Information System (INIS)

Kozma, R.

1989-01-01

A specially-equipped simulated fuel assembly has been placed into the core of the 2 MW research reactor of the IRI, Delft. In this paper the recent results concerning the detection of coolant boiling in the simulated fuel assembly are introduced. Applying the theory of boiling temperature noise, different stages of boiling, i.e. one-phase flow, subcooled boiling, volume boiling, were identified in the measurements using the low-frequency noise components of the thermocouple signals. It has been ascertained that neutron noise spectra remained unchanged when subcooled boiling appeared, and that they changed reasonably only when developed volume boiling took place in the channels. At certain neutron detector positions neutron spectra did not vary at all, although developed volume boiling occurred at a distance of 3-4 cm from these neutron detectors. This phenomenon was applied in studying the field-of-view of neutron detectors

Flow measurements using noise signals of axially displaced thermocouples

Energy Technology Data Exchange (ETDEWEB)

Kozma, R.; Hoogenboom, J.E. (Interuniversitair Reactor Inst., Delft (Netherlands))

1990-01-01

Determination of the flow rate of the coolant in the cooling channels of nuclear reactors is an important aspect of core monitoring. It is usually impossible to measure the flow by flowmeters in the individual channels due to the lack of space and safety reasons. An alternative method is based on the analysis of noise signals of the available in-core detectors. In such a noise method, a transit time which characterises the propagation of thermohydraulic fluctuations (density or temperature fluctuations) in the coolant is determined from the correlation between the noise signals of axially displaced detectors. In this paper, the results of flow measurements using axially displaced thermocouples in the channel wall will be presented. The experiments have been performed in a simulated MRT-type fuel assembly located in the research reactor HOR of the Interfaculty Reactor Institute, Delft. It was found that the velocities obtained via temperature noise correlation methods are significantly larger than the area-averaged velocity in the single-phase coolant flow. Model calculations show that the observed phenomenon can be explained by effects due to the radial velocity distribution in the channel. (author).

Sound characteristics of Terapon jorbua as a response to temperature changes

Science.gov (United States)

Amron; Jaya, I.; Hestirianoto, T.; Juterzenka, K. v.

2017-10-01

The change of water temperature has potential impact on the behavior of aquatic animal including fish which generated by their sound productivity and characteristics. This research aimed to study the response of sound productivity and characteristics of Terapon jorbua to temperature change. As a response to temperature increase, T. jorbua to have decreased the number of sound productivity. Two characteristic parameters of fish sound, i.e. intensity and frequency as were quadratic increased during the water temperature rises. In contrast, pulse duration was quadratic decreased.

Resistance temperature sensor aging degradation identification using LCSR (Loop Current Step Response) test

International Nuclear Information System (INIS)

Santos, Roberto Carlos dos; Goncalves, Iraci Martine Pereira

2013-01-01

Most critical process temperatures in nuclear power plants are measured using RTD (Resistance Temperature Detector) and thermocouples. In a PWR (Pressure Water Reactor) plant, the primary coolant temperature and feedwater temperature are measured using RTDs, and the temperature of the water that exits the reactor core is measured using thermocouples. These thermocouples are mainly used for temperature monitoring purposes and are therefore not generally subject to very stringent requirements for accuracy and response-time performance. In contrast, primary coolant RTDs typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. The response time of RTDs and thermocouples has been characterized by a single parameter called the Plunge Time Constant. This is defined as the time it takes the sensor output to achieve 63.2 percent of its final value after a step change in temperature is impressed on its surface. This step change is typically achieved by suddenly immersing the sensor in a rotating tank of water, called Plunge Test. In nuclear reactors, however, plunge testing is inconvenient because the sensor must be removed from the reactor coolant piping and taken to a laboratory for testing. Nuclear reactor service conditions of 150 bar and 300°C are difficult to reproduce in the laboratory. Therefore, all laboratory tests are performed at much milder conditions, and the results are extrapolated to service conditions. This leads to significant errors in the measurement of sensor response times and an insitu test method called LCSR - Loop Current Step Response test was developed in the mid-1970s to measure remotely the response time of RTDs. In the LCSR method, the sensing element is heated by an electric current; the current causes Joule heating in the sensor and results in a temperature transient inside the sensor. The temperature transient in the element is recorded, and from this transient, the

Dose-response characteristics of an amorphous silicon EPID

International Nuclear Information System (INIS)

Winkler, Peter; Hefner, Alfred; Georg, Dietmar

2005-01-01

Electronic portal imaging devices (EPIDs) were originally developed for the purpose of patient setup verification. Nowadays, they are increasingly used as dosimeters (e.g., for IMRT verification and linac-specific QA). A prerequisite for any clinical dosimetric application is a detailed understanding of the detector's dose-response behavior. The aim of this study is to investigate the dosimetric properties of an amorphous silicon EPID (Elekta IVIEWGT) with respect to three photon beam qualities: 6, 10, and 25 MV. The EPID showed an excellent temporal stability on short term as well as on long term scales. The stability throughout the day was strongly influenced by warming up, which took several hours and affected EPID response by 2.5%. Ghosting effects increased the sensitivity of the EPID. They became more pronounced with decreasing time intervals between two exposures as well as with increasing dose. Due to ghosting, changes in pixel sensitivity amounted up to 16% (locally) for the 25 MV photon beam. It was observed that the response characteristics of our EPID depended on dose as well as on dose rate. Doubling the dose rate increased the EPID sensitivity by 1.5%. This behavior was successfully attributed to a dose per frame effect, i.e., a nonlinear relationship between the EPID signal and the dose which was delivered to the panel between two successive readouts. The sensitivity was found to vary up to 10% in the range of 1 to 1000 monitor units. This variation was governed by two independent effects. For low doses, the EPID signal was reduced due to the linac's changing dose rate during startup. Furthermore, the detector reading was influenced by intrabeam variations of EPID sensitivity, namely, an increase of detector response during uniform exposure. For the beam qualities which were used, the response characteristics of the EPID did not depend on energy. Differences in relative dose-response curves resulted from energy dependent temporal output

A preliminary study of oxidation-resistant coatings on refractory-metal thermocouple sheaths

International Nuclear Information System (INIS)

Wilkins, S.C.

1985-01-01

The need to make reliable temperature measurements up to 2200 0 C or higher in steam environments during in-pile nuclear fuel damage tests led to a search for oxidation-resistant coatings for the refractory-metal sheaths used to enclose and protect thermocouples used for such measurements. Iridium, thoria, and thoria-over-iridium coatings were separately sputter-deposited on molybdenum-rhenium alloy protection tubes for evaluation. The coated samples were individually heated in flowing steam in an induction furnace. An extension tube welded to each sample was connected to a vacuum pump and gauge; failure of the sample was detected by noting the degradation of the vacuum maintained in the sample. Relatively heavy coatings of iridium provided a modest degree of oxidation protection at the temperatures of interest. Thoria coatings provided no significant protection at those temperatures, compared to uncoated control samples

Ultrasonic thermometry for nuclear power plants

International Nuclear Information System (INIS)

Saravana Kumar, S.; Arunraj, A.L.R.; Swaminathan, K.

2013-01-01

Ultrasonic transducer provides a method of measurement of temperature in industrial tanks and boilers containing different liquids with varied salt content. This method is used to measure the average temperature continuously where other traditional methods available do not offer. Traditional methods used for temperature measurement like infrared thermometers, thermocouples, measures temperature at a single location. Numerous thermocouples are to be fixed at various part of the boiler in order to measure the temperature of the entire boiler, which incurs high cost. Reliability of the system decreases, with increasing number of thermocouples. When they fail at a point, the time incurred in finding the faulty part or faulty thermocouple is high. Ultrasonic transducer provides continuous measurement for all different characteristic liquids with higher accuracy and lesser response time. Fault location and clearance time is also less in ultrasonic measurement method, since only a couple of transducers used for the entire boiler structure. Additionally ultrasonic thermometry along support measuring electronic system can be built of low cost. (author)

Description of an identification method of thermocouple time constant based on application of recursive numerical filtering to temperature fluctuation

International Nuclear Information System (INIS)

Bernardin, B.; Le Guillou, G.; Parcy, JP.

1981-04-01

Usual spectral methods, based on temperature fluctuation analysis, aiming at thermocouple time constant identification are using an equipment too much sophisticated for on-line application. It is shown that numerical filtering is optimal for this application, the equipment is simpler than for spectral methods and less samples of signals are needed for the same accuracy. The method is described and a parametric study was performed using a temperature noise simulator [fr

Operating Temperatures of a Sodium-Cooled Exhaust Valve as Measured by a Thermocouple

Science.gov (United States)

Sanders, J. C.; Wilsted, H. D.; Mulcahy, B. A.

1943-01-01

A thermocouple was installed in the crown of a sodium-cooled exhaust valve. The valve was then tested in an air-cooled engine cylinder and valve temperatures under various engine operating conditions were determined. A temperature of 1337 F was observed at a fuel-air ratio of 0.064, a brake mean effective pressure of 179 pounds per square inch, and an engine speed of 2000 rpm. Fuel-air ratio was found to have a large influence on valve temperature, but cooling-air pressure and variation in spark advance had little effect. An increase in engine power by change of speed or mean effective pressure increased the valve temperature. It was found that the temperature of the rear spark-plug bushing was not a satisfactory indication of the temperature of the exhaust valve.

Comparison of two surface temperature measurement using thermocouples and infrared camera

Directory of Open Access Journals (Sweden)

Michalski Dariusz

2017-01-01

Full Text Available This paper compares two methods applied to measure surface temperatures at an experimental setup designed to analyse flow boiling heat transfer. The temperature measurements were performed in two parallel rectangular minichannels, both 1.7 mm deep, 16 mm wide and 180 mm long. The heating element for the fluid flowing in each minichannel was a thin foil made of Haynes-230. The two measurement methods employed to determine the surface temperature of the foil were: the contact method, which involved mounting thermocouples at several points in one minichannel, and the contactless method to study the other minichannel, where the results were provided with an infrared camera. Calculations were necessary to compare the temperature results. Two sets of measurement data obtained for different values of the heat flux were analysed using the basic statistical methods, the method error and the method accuracy. The experimental error and the method accuracy were taken into account. The comparative analysis showed that although the values and distributions of the surface temperatures obtained with the two methods were similar but both methods had certain limitations.

Specific features of thermocouple calorimeter application for measurements of pulsed X-ray emission from plasma

International Nuclear Information System (INIS)

Gavrilov, V. V.; Fasakhov, I. K.

2012-01-01

It is shown that the accuracy of time-integrated measurements of pulsed X-ray emission from hot plasma with calibrated thermocouple calorimeters is mainly determined by two factors. The first and the most important factor is heating of the filter by the absorbed X-rays; as a result, the calorimeter measures the thermal radiation of the filter, which causes appreciable distortion of the temporal profile and amplitude of the recorded signal. The second factor is the dependence of the effective depth of X-ray absorption in the dielectric that covers the entrance window of the calorimeter on the energy of X-ray photons, i.e., on the recorded radiation spectrum. The results of model calculations of the calorimeter signal are compared with the experimental data.

Seismic response characteristics of full-size buildings with base isolation system

International Nuclear Information System (INIS)

Wang, C.Y.; Gvildys, J.

1991-01-01

This paper investigates the response characteristics of full-size reinforced concrete buildings via numerical simulations and actual observations. The test facility consists of two identical three-story buildings constructed side by side at Tohoku University in Sendai, Japan. Since the installation of high-damping isolation bearings in April 1989, data from over twenty earthquakes have been recorded. In this paper, three representative earthquake records, No. 2, No. 6, and No. 17 are used to study the detailed response characteristics. Numerical simulations are carried out with the system response program, SISEC. In general, good agreement has been found between numerical solutions and actual observations. The system is stiff enough to prevent the building displacement under minor earthquakes and wind loads, but is relatively soft for reducing the acceleration response during earthquakes with moderate and strong ground motion. Lessons learned in this effort are applicable to base isolation design of nuclear power plants. 7 refs., 16 figs., 3 tabs

Attachment of lead wires to thin film thermocouples mounted on high temperature materials using the parallel gap welding process

Science.gov (United States)

Holanda, Raymond; Kim, Walter S.; Pencil, Eric; Groth, Mary; Danzey, Gerald A.

1990-01-01

Parallel gap resistance welding was used to attach lead wires to sputtered thin film sensors. Ranges of optimum welding parameters to produce an acceptable weld were determined. The thin film sensors were Pt13Rh/Pt thermocouples; they were mounted on substrates of MCrAlY-coated superalloys, aluminum oxide, silicon carbide and silicon nitride. The entire sensor system is designed to be used on aircraft engine parts. These sensor systems, including the thin-film-to-lead-wire connectors, were tested to 1000 C.

Hydrological response characteristics of Mediterranean catchments: a review

OpenAIRE

Merheb , M.; Moussa , R.; Abdallah , C.; Colin , F.; Perrin , C.; Baghdadi , N.

2016-01-01

International audience; This work examines 140 hydrological studies conducted in the Mediterranean region. It identifies key characteristics of the hydrological responses of Mediterranean catchments at various time scales and compares different methods and modelling approaches used for individualcatchmentstudies. The study area is divided into the northwestern (NWM), eastern (EM) and southern (SM) Mediterranean. The analysis indicates regional discrepancies in which the NWM shows the most ext...

Response characteristics of selected personnel neutron dosimeters

International Nuclear Information System (INIS)

McDonald, J.C.; Fix, J.J.; Hadley, R.T.; Holbrook, K.L.; Yoder, R.C.; Roberson, P.L.; Endres, G.W.R.; Nichols, L.L.; Schwartz, R.B.

1983-09-01

Performance characteristics of selected personnel neutron dosimeters in current use at Department of Energy (DOE) facilities were determined from their evaluation of neutron dose equivalent received after irradiations with specific neutron sources at either the National Bureau of Standards (NBS) or the Pacific Northwest Laboratory (PNL). The characteristics assessed included: lower detection level, energy response, precision and accuracy. It was found that when all of the laboratories employed a common set of calibrations, the overall accuracy was approximately +-20%, which is within uncertainty expected for these dosimeters. For doses above 80 mrem, the accuracy improved to better than 10% when a common calibration was used. Individual differences found in this study may reflect differences in calibration technique rather than differences in the dose rates of actual calibration standards. Second, at dose rates above 100 mrem, the precision for the best participants was generally below +-10% which is also within expected limits for these types of dosimeters. The poorest results had a standard deviation of about +-25%. At the lowest doses, which were sometimes below the lower detection limit, the precision often approached or exceeded +-100%. Third, the lower level of detection for free field 252 Cf neutrons generally ranged between 20 and 50 mrem. Fourth, the energy dependence study provided a characterization of the response of the dosimeters to neutron energies far from the calibration energy. 11 references, 22 figures, 26 tables

Boiling point measurement of a small amount of brake fluid by thermocouple and its application.

Science.gov (United States)

Mogami, Kazunari

2002-09-01

This study describes a new method for measuring the boiling point of a small amount of brake fluid using a thermocouple and a pear shaped flask. The boiling point of brake fluid was directly measured with an accuracy that was within approximately 3 C of that determined by the Japanese Industrial Standards method, even though the sample volume was only a few milliliters. The method was applied to measure the boiling points of brake fluid samples from automobiles. It was clear that the boiling points of brake fluid from some automobiles dropped to approximately 140 C from about 230 C, and that one of the samples from the wheel cylinder was approximately 45 C lower than brake fluid from the reserve tank. It is essential to take samples from the wheel cylinder, as this is most easily subjected to heating.

Scanning thermal microscopy based on a quartz tuning fork and a micro-thermocouple in active mode (2ω method)

International Nuclear Information System (INIS)

Bontempi, Alexia; Nguyen, Tran Phong; Salut, Roland; Thiery, Laurent; Teyssieux, Damien; Vairac, Pascal

2016-01-01

A novel probe for scanning thermal microscope using a micro-thermocouple probe placed on a Quartz Tuning Fork (QTF) is presented. Instead of using an external deflection with a cantilever beam for contact detection, an original combination of piezoelectric resonator and thermal probe is employed. Due to a non-contact photothermal excitation principle, the high quality factor of the QTF allows the probe-to-surface contact detection. Topographic and thermal scanning images obtained on a specific sample points out the interest of our system as an alternative to cantilevered resistive probe systems which are the most spread.

Scanning thermal microscopy based on a quartz tuning fork and a micro-thermocouple in active mode (2ω method).

Science.gov (United States)

Bontempi, Alexia; Nguyen, Tran Phong; Salut, Roland; Thiery, Laurent; Teyssieux, Damien; Vairac, Pascal

2016-06-01

A novel probe for scanning thermal microscope using a micro-thermocouple probe placed on a Quartz Tuning Fork (QTF) is presented. Instead of using an external deflection with a cantilever beam for contact detection, an original combination of piezoelectric resonator and thermal probe is employed. Due to a non-contact photothermal excitation principle, the high quality factor of the QTF allows the probe-to-surface contact detection. Topographic and thermal scanning images obtained on a specific sample points out the interest of our system as an alternative to cantilevered resistive probe systems which are the most spread.

Scanning thermal microscopy based on a quartz tuning fork and a micro-thermocouple in active mode (2ω method)

Energy Technology Data Exchange (ETDEWEB)

Bontempi, Alexia; Nguyen, Tran Phong; Salut, Roland; Thiery, Laurent; Teyssieux, Damien; Vairac, Pascal [FEMTO-ST Institute UMR 6174, Université de Franche-Comté, CNRS, ENSMM, UTBM, 15B Avenue des Montboucons, F-25030 Besançon (France)

2016-06-15

A novel probe for scanning thermal microscope using a micro-thermocouple probe placed on a Quartz Tuning Fork (QTF) is presented. Instead of using an external deflection with a cantilever beam for contact detection, an original combination of piezoelectric resonator and thermal probe is employed. Due to a non-contact photothermal excitation principle, the high quality factor of the QTF allows the probe-to-surface contact detection. Topographic and thermal scanning images obtained on a specific sample points out the interest of our system as an alternative to cantilevered resistive probe systems which are the most spread.

Skull base chordomas: analysis of dose-response characteristics

International Nuclear Information System (INIS)

Niemierko, Andrzej; Terahara, Atsuro; Goitein, Michael

1997-01-01

Objective: To extract dose-response characteristics from dose-volume histograms and corresponding actuarial survival statistics for 115 patients with skull base chordomas. Materials and Methods: We analyzed data for 115 patients with skull base chordoma treated with combined photon and proton conformal radiotherapy to doses in the range 66.6Gy - 79.2Gy. Data set for each patient included gender, histology, age, tumor volume, prescribed dose, overall treatment time, time to recurrence or time to last observation, target dose-volume histogram, and several dosimetric parameters (minimum/mean/median/maximum target dose, percent of the target volume receiving the prescribed dose, dose to 90% of the target volume, and the Equivalent Uniform Dose (EUD). Data were analyzed using the Kaplan-Meier survivor function estimate, the proportional hazards (Cox) model, and parametric modeling of the actuarial probability of recurrence. Parameters of dose-response characteristics were obtained using the maximum likelihood method. Results: Local failure developed in 42 (36%) of patients, with actuarial local control rates at 5 years of 59.2%. The proportional hazards model revealed significant dependence of gender on the probability of recurrence, with female patients having significantly poorer prognosis (hazard ratio of 2.3 with the p value of 0.008). The Wilcoxon and the log-rank tests of the corresponding Kaplan-Meier recurrence-free survival curves confirmed statistical significance of this effect. The Cox model with stratification by gender showed significance of tumor volume (p=0.01), the minimum target dose (p=0.02), and the EUD (p=0.02). Other parameters were not significant at the α level of significance of 0.05, including the prescribed dose (p=0.21). Parametric analysis using a combined model of tumor control probability (to account for non-uniformity of target dose distribution) and the Weibull failure time model (to account for censoring) allowed us to estimate

Response to baricitinib therapy in patients with rheumatoid arthritis with inadequate response to csDMARDs as a function of baseline characteristics.

Science.gov (United States)

Kremer, Joel M; Schiff, Michael; Muram, David; Zhong, Jinglin; Alam, Jahangir; Genovese, Mark C

2018-01-01

We analysed the effects of baseline characteristics on the safety and efficacy of baricitinib in patients with rheumatoid arthritis (RA) with inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) from two phase III trials. In RA-BEAM (NCT01710358), patients with inadequate response to methotrexate were randomised to placebo, baricitinib 4 mg or adalimumab 40 mg. RA-BUILD (NCT01721057) patients had inadequate response to ≥1 csDMARDs and were randomised to either placebo or once-daily baricitinib (2 or 4 mg). Both study populations were naïve to biologic DMARDs (bDMARDs). Primary end point for both studies was American College of Rheumatology 20% improvement (ACR20) response at week 12. Pooled data from the two trials were analysed post hoc based on select subgroups defined by age, previous csDMARD use, baseline RA disease activity, etc, with assessment of clinical and safety outcomes at week 12 and radiographic outcomes at week 24 for the baricitinib 4 mg and placebo-treated patients. Efficacy was observed with baricitinib 4 mg treatment irrespective of patient demographics and baseline disease characteristics. ORs primarily favoured baricitinib over placebo in the ACR20 response. In other outcomes such as Disease Activity Score for 28 joints based on high-sensitivity C reactive protein levels, Simplified Disease Activity Index score ≤11 and radiographic progression, baricitinib 4 mg showed better responses than placebo regardless of baseline characteristics. Safety events were more common in patients over 65 years, but similar between baricitinib 4 mg and placebo patients. Baseline characteristics did not substantially affect clinical response to baricitinib 4 mg in patients with RA with inadequate response to csDMARDs.

n+ GaAs/AuGeNi-Au Thermocouple-Type RF MEMS Power Sensors Based on Dual Thermal Flow Paths in GaAs MMIC

Directory of Open Access Journals (Sweden)

Zhiqiang Zhang

2017-06-01

Full Text Available To achieve radio frequency (RF power detection, gain control, and circuit protection, this paper presents n+ GaAs/AuGeNi-Au thermocouple-type RF microelectromechanical system (MEMS power sensors based on dual thermal flow paths. The sensors utilize a conversion principle of RF power-heat-voltage, where a thermovoltage is obtained as the RF power changes. To improve the heat transfer efficiency and the sensitivity, structures of two heat conduction paths are designed: one in which a thermal slug of Au is placed between two load resistors and hot junctions of the thermocouples, and one in which a back cavity is fabricated by the MEMS technology to form a substrate membrane underneath the resistors and the hot junctions. The improved sensors were fabricated by a GaAs monolithic microwave integrated circuit (MMIC process. Experiments show that these sensors have reflection losses of less than −17 dB up to 12 GHz. At 1, 5, and 10 GHz, measured sensitivities are about 63.45, 53.97, and 44.14 µV/mW for the sensor with the thermal slug, and about 111.03, 94.79, and 79.04 µV/mW for the sensor with the thermal slug and the back cavity, respectively.

Who is responsible for food risks? The influence of risk type and risk characteristics

DEFF Research Database (Denmark)

Leikas, Sointu; Lindeman, Marjaana; Roininen, Katariina

2009-01-01

The influence of food risk type and risk characteristics on food risk responsibility judgments was studied. A total of 1270 Finnish consumers judged their personal responsibility and the responsibility of three non-personal targets, industry, retail, and society, in relation to six food...

Core-Shell Structured Electro- and Magneto-Responsive Materials: Fabrication and Characteristics

Directory of Open Access Journals (Sweden)

Hyoung Jin Choi

2014-11-01

Full Text Available Core-shell structured electrorheological (ER and magnetorheological (MR particles have attracted increasing interest owing to their outstanding field-responsive properties, including morphology, chemical and dispersion stability, and rheological characteristics of shear stress and yield stress. This study covers recent progress in the preparation of core-shell structured materials as well as their critical characteristics and advantages. Broad emphasises from the synthetic strategy of various core-shell particles to their feature behaviours in the magnetic and electric fields have been elaborated.

Study of Thermocurrents in ILC cavities via measurements of the Seebeck Effect in niobium, titanium, and stainless steel thermocouples

Energy Technology Data Exchange (ETDEWEB)

Cooley, Victoria [Univ. of Wisconsin, Madison, WI (United States)

2014-01-01

The goals of Fermilab’s Superconductivity and Radio Frequency Development Department are to engineer, fabricate, and improve superconducting radio frequency (SCRF) cavities in the interest of advancing accelerator technology. Improvement includes exploring possible limitations on cavity performance and mitigating such impediments. This report focuses on investigating and measuring the Seebeck Effect observed in cavity constituents titanium, niobium, and stainless steel arranged in thermocouples. These junctions exist between cavities, helium jackets, and bellows, and their connection can produce a loop of electrical current and magnetic flux spontaneously during cooling. The experimental procedure and results are described and analyzed. Implications relating the results to cavity performance are discussed.

Time response characteristics of X-ray detector system on Silex-Ⅰ laser facility

International Nuclear Information System (INIS)

Yi Rongqing; He Xiao'an; Li Hang; Du Huabing; Zhang Haiying; Cao Zhurong

2013-01-01

On the Silex-Ⅰ laser facility, the time response characteristics of XRD detector were studied. A laser with a pulse of 32 fs and a wavelength of 800 nm was used to irradiate a plane Au target. X-ray calibrated method of time of exposure X-ray framing camera and time resolution of X-ray streak camera was explored. The time response characteristics of XRD detector and time process of X-ray emission were obtained from experiment. We obtained X-ray calibration method of time of exposure X-ray framing camera and time resolution of X-ray streak camera. (authors)

n⁺ GaAs/AuGeNi-Au Thermocouple-Type RF MEMS Power Sensors Based on Dual Thermal Flow Paths in GaAs MMIC.

Science.gov (United States)

Zhang, Zhiqiang; Liao, Xiaoping

2017-06-17

To achieve radio frequency (RF) power detection, gain control, and circuit protection, this paper presents n⁺ GaAs/AuGeNi-Au thermocouple-type RF microelectromechanical system (MEMS) power sensors based on dual thermal flow paths. The sensors utilize a conversion principle of RF power-heat-voltage, where a thermovoltage is obtained as the RF power changes. To improve the heat transfer efficiency and the sensitivity, structures of two heat conduction paths are designed: one in which a thermal slug of Au is placed between two load resistors and hot junctions of the thermocouples, and one in which a back cavity is fabricated by the MEMS technology to form a substrate membrane underneath the resistors and the hot junctions. The improved sensors were fabricated by a GaAs monolithic microwave integrated circuit (MMIC) process. Experiments show that these sensors have reflection losses of less than -17 dB up to 12 GHz. At 1, 5, and 10 GHz, measured sensitivities are about 63.45, 53.97, and 44.14 µ V/mW for the sensor with the thermal slug, and about 111.03, 94.79, and 79.04 µ V/mW for the sensor with the thermal slug and the back cavity, respectively.

Response characteristics of reactor building on weathered soft rock ground

International Nuclear Information System (INIS)

Hirata, Kazuta; Tochigi, Hitoshi

1991-01-01

The purpose of this study is to investigate the seismic stability of nuclear power plants on layered soft bedrock grounds, focusing on the seismic response of reactor buildings. In this case, the soft bedrock grounds refer to the weathered soft bedrocks with several tens meter thickness overlaying hard bedrocks. Under this condition, there are two subjects regarding the estimation of the seismic response of reactor buildings. One is the estimation of the seismic response of surface ground, and another is the estimation of soil-structure interaction characteristics for the structures embedded in the layered grounds with low impedandce ratio between the surface ground and the bedrock. Paying attention to these subjects, many cases of seismic response analysis were carried out, and the following facts were clarified. In the soft rock grounds overlaying hard bedrocks, it was proved that the response acceleration was larger than the case of uniform hard bedrocks. A simplified sway and rocking model was proposed to consider soil-structure interaction. It was proved that the response of reactor buildings was small when the effect of embedment was considered. (K.I.)

Thermocouple and infrared sensor-based measurement of temperature distribution in metal cutting.

Science.gov (United States)

Kus, Abdil; Isik, Yahya; Cakir, M Cemal; Coşkun, Salih; Özdemir, Kadir

2015-01-12

In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.

Dynamic response characteristics of dual flow-path integrally bladed rotors

Science.gov (United States)

Beck, Joseph A.; Brown, Jeffrey M.; Scott-Emuakpor, Onome E.; Cross, Charles J.; Slater, Joseph C.

2015-02-01

New turbine engine designs requiring secondary flow compression often look to dual flow-path integrally bladed rotors (DFIBRs) since these stages have the ability to perform work on the secondary, or bypassed, flow-field. While analogous to traditional integrally bladed rotor stages, DFIBR designs have many differences that result in unique dynamic response characteristics that must be understood to avoid fatigue. This work investigates these characteristics using reduced-order models (ROMs) that incorporate mistuning through perturbations to blade frequencies. This work provides an alternative to computationally intensive geometric-mistuning approaches for DFIBRs by utilizing tuned blade mode reductions and substructure coupling in cyclic coordinates. Free and forced response results are compared to full finite element model (FEM) solutions to determine if any errors are related to the reduced-order model formulation reduction methods. It is shown that DFIBRs have many more frequency veering regions than their single flow-path integrally blade rotor (IBR) counterparts. Modal families are shown to transition between system, inner-blade, and outer-blade motion. Furthermore, findings illustrate that while mode localization of traditional IBRs is limited to a single or small subset of blades, DFIBRs can have modal energy localized to either an inner- or outer-blade set resulting in many blades responding above tuned levels. Lastly, ROM forced response predictions compare well to full FEM predictions for the two test cases shown.

Experimental investigation of transient temperature characteristic in high power fiber laser cutting of a thick steel plate

Science.gov (United States)

Phi Long, Nguyen; Matsunaga, Yukihiro; Hanari, Toshihide; Yamada, Tomonori; Muramatsu, Toshiharu

2016-10-01

Experiment of temperature measurement was performed to investigate the transient temperature characteristics of molten metal during laser cutting. The aim of this study was to establish a method for measuring the surface temperature variation near the molten pool correlated with changes in cutting parameters. The relationship between temperature inside the kerf cut and characteristic of the cut surface was investigated by using thermography and thermocouples. Results show strong correlations between the transient temperatures and the thermal image for different cutting conditions. In addition, two-color thermometer has been used to obtain radiation intensity emitted from the irradiating zone as a function of operating conditions. Experiments have shown that one can detect the cutting quality by characterization of the surface temperature during laser cutting process.

Uniformity index measurement technology using thermocouples to improve performance in urea-selective catalytic reduction systems

Science.gov (United States)

Park, Sangki; Oh, Jungmo

2018-05-01

The current commonly used nitrogen oxides (NOx) emission reduction techniques employ hydrocarbons (HCs), urea solutions, and exhaust gas emissions as the reductants. Two of the primary denitrification NOx (DeNOx) catalyst systems are the HC-lean NOx trap (HC-LNT) catalyst and urea-selective catalytic reduction (urea-SCR) catalyst. The secondary injection method depends on the type of injector, injection pressure, atomization, and spraying technique. In addition, the catalyst reaction efficiency is directly affected by the distribution of injectors; hence, the uniformity index (UI) of the reductant is very important and is the basis for system optimization. The UI of the reductant is an indicator of the NOx conversion efficiency (NCE), and good UI values can reduce the need for a catalyst. Therefore, improving the UI can reduce the cost of producing a catalytic converter, which are expensive due to the high prices of the precious metals contained therein. Accordingly, measurement of the UI is an important process in the development of catalytic systems. Two of the commonly used methods for measuring the reductant UI are (i) measuring the exhaust emissions at many points located upstream/downstream of the catalytic converter and (ii) acquisition of a reductant distribution image on a section of the exhaust pipe upstream of the catalytic converter. The purpose of this study is to develop a system and measurement algorithms to measure the exothermic response distribution in the exhaust gas as the reductant passes through the catalytic converter of the SCR catalyst system using a set of thermocouples downstream of the SCR catalyst. The system is used to measure the reductant UI, which is applied in real-time to the actual SCR system, and the results are compared for various types of mixtures for various engine operating conditions and mixer types in terms of NCE.

INTEGRAL/SPI γ-ray line spectroscopy. Response and background characteristics

Science.gov (United States)

Diehl, Roland; Siegert, Thomas; Greiner, Jochen; Krause, Martin; Kretschmer, Karsten; Lang, Michael; Pleintinger, Moritz; Strong, Andrew W.; Weinberger, Christoph; Zhang, Xiaoling

2018-03-01

Context. The space based γ-ray observatory INTEGRAL of the European Space Agency (ESA) includes the spectrometer instrument "SPI". This is a coded mask telescope featuring a 19-element Germanium detector array for high-resolution γ-ray spectroscopy, encapsulated in a scintillation detector assembly that provides a veto for background from charged particles. In space, cosmic rays irradiate spacecraft and instruments, which, in spite of the vetoing detectors, results in a large instrumental background from activation of those materials, and leads to deterioration of the charge collection properties of the Ge detectors. Aim. We aim to determine the measurement characteristics of our detectors and their evolution with time, that is, their spectral response and instrumental background. These incur systematic variations in the SPI signal from celestial photons, hence their determination from a broad empirical database enables a reduction of underlying systematics in data analysis. For this, we explore compromises balancing temporal and spectral resolution within statistical limitations. Our goal is to enable modelling of background applicable to spectroscopic studies of the sky, accounting separately for changes of the spectral response and of instrumental background. Methods: We use 13.5 years of INTEGRAL/SPI data, which consist of spectra for each detector and for each pointing of the satellite. Spectral fits to each such spectrum, with independent but coherent treatment of continuum and line backgrounds, provides us with details about separated background components. From the strongest background lines, we first determine how the spectral response changes with time. Applying symmetry and long-term stability tests, we eliminate degeneracies and reduce statistical fluctuations of background parameters, with the aim of providing a self-consistent description of the spectral response for each individual detector. Accounting for this, we then determine how the

Study on vertical seismic response characteristics of deeply embedded reactor building

International Nuclear Information System (INIS)

Morishita, H.; Nakamura, N.; Uchiyama, S.; Fukuoka, A.; Ishizaki, M.

1993-01-01

This paper describes vertical response characteristics, especially effects of embedment, and analytical methods for seismic design of a deeply embedded reactor building. The influence of embedment on vertical response was found to be minimal by evaluating results of forced vibration tests of a reactor building model and performing simplified analyses. Subsequently, simulation analyses of the forced vibration test and actual earthquake induced response were performed using both the axisymmetric FEM model and the simplified mass and spring model. It was concluded that the analytical models taking the embedment into the consideration closely simulated the observation records, and the omission of embedment in the analyses tended to increase the predicted response which was conservative in respect an actual design consideration. (author)

A study on operators' cognitive response characteristics to the computerized working environment

International Nuclear Information System (INIS)

Lee, Yong Hee; Lee, Jang Soo; Suh, Sang Moon; Lee, Hyun Cheol; Jung, Kwang Tae; Lee, Dhong Ha

1998-12-01

Although the introduction of computerized working environment to the nuclear facilities, the study on the human factors impacts of computers and automation has not been enough like the other industries. It is necessary to prepare the way to cope with the negative aspects in spite of many positive aspects of computerization in nuclear. This study is an empirical study including the survey of the human factor concerning, especially to the cognitive response of operators' and the experiments on the error proneness. At first, we survey the design and its changes of operator interface and interaction in nuclear power plants, and conclude five human factor issues. We discuss situation awareness issues as one of the major human factor concerning, and the assessment method. Secondly, a questionnaire and interviews survey to the operator's response characteristics are performed for possible criterion measures tot he in-depth study on the cognitive characteristics. Finally, several experiments are conducted to test the error proneness. The issues and findings of this study could be utilized to any further study on the cognitive characteristic of operators to the computerized work environment

Analytical evaluation on dynamical response characteristics of reduced-moderation water reactor with tight-lattice core under natural circulation core cooling

International Nuclear Information System (INIS)

Ishikawa, Nobuyuki; Okubo, Tsutomu

2009-01-01

The time-domain analyses with TRAC-BF1 code were performed for clarifying the dynamical response characteristics of the reduced-moderation water reactor (RMWR) with tight-lattice core configuration. The response characteristics were evaluated based on the step response basically utilized for dynamical system evaluation. As for the most fundamental dynamical characteristics, the channel flow response characteristics of single fuel assembly were evaluated. In the evaluation, the appropriate single-phase pressure drop setting at the inlet orifice was determined in terms of response stability from the design viewpoint. In addition, from the investigation on the relation of the response and transit time of coolant, it is confirmed that the channel flow response of RMWR is dominated by the transit time of vapor phase resulting from a high void fraction operation condition. As for a natural circulation flow response, it is clarified that the response is strongly influenced by the effect of two-phase pressure loss owing to a high void fraction condition. The reactor power response with reactivity feedback shows quite stable response characteristics on account of the small absolute value of void reactivity coefficient.

Stability of response characteristics of a Delphi panel: application of bootstrap data expansion

Directory of Open Access Journals (Sweden)

Cole Bryan R

2005-12-01

Full Text Available Abstract Background Delphi surveys with panels of experts in a particular area of interest have been widely utilized in the fields of clinical medicine, nursing practice, medical education and healthcare services. Despite this wide applicability of the Delphi methodology, there is no clear identification of what constitutes a sufficient number of Delphi survey participants to ensure stability of results. Methods The study analyzed the response characteristics from the first round of a Delphi survey conducted with 23 experts in healthcare quality and patient safety. The panel members had similar training and subject matter understanding of the Malcolm Baldrige Criteria for Performance Excellence in Healthcare. The raw data from the first round sampling, which usually contains the largest diversity of responses, were augmented via bootstrap sampling to obtain computer-generated results for two larger samples obtained by sampling with replacement. Response characteristics (mean, trimmed mean, standard deviation and 95% confidence intervals for 54 survey items were compared for the responses of the 23 actual study participants and two computer-generated samples of 1000 and 2000 resampling iterations. Results The results from this study indicate that the response characteristics of a small expert panel in a well-defined knowledge area are stable in light of augmented sampling. Conclusion Panels of similarly trained experts (who possess a general understanding in the field of interest provide effective and reliable utilization of a small sample from a limited number of experts in a field of study to develop reliable criteria that inform judgment and support effective decision-making.

Combustion characteristics of crude jatropha oil droplets using rhodium liquid as a homogeneous combustion catalyst

Science.gov (United States)

Nanlohy, Hendry Y.; Wardana, I. N. G.; Hamidi, N.; Yuliati, L.

2018-01-01

Combustion characteristics of crude jatropha oil droplet at room temperature with and without catalyst have been studied experimentally. Its combustion characteristics have been observed by igniting the oil droplet on a junction of a thermocouple, and the combustion characteristics of oil droplets are observed using a high-speed camera. The results show that the uniqueness of crude jatropha oil as alternative fuel is evidenced by the different stages of combustion caused by thermal cracking in burning droplets. The results also show that the role of the catalyst is not only an accelerator agent, but there are other unique functions and roles as a stabilizer. Moreover, the results also found that the catalyst was able to shorten the ignition timing and burnout time. This phenomenon proves that the presence of catalysts alters and weakens the structure of the triglyceride geometry so that the viscosity and flash point is reduced, the fuel absorbs heat well and flammable.

Statistical uncertainty of response characteristic of building-appendage system for spectrum-compatible artificial earthquake motion

International Nuclear Information System (INIS)

Kurosaki, A.; Kozeki, M.

1981-01-01

Spectrum-compatible artificial time histories of ground motions are frequently used for the seismic design of nuclear power plant structures and components. However, statistical uncertainty of the responses of building structures and mechanical components mounted on the building (building-appendage systems) are anticipated, since an artificial time history is no more than one sample from a population of such time histories that match a specified design response spectrum. This uncertainty may spoil the reliability of the seismic design and therefore the extent of the uncertainty of the response characteristic is a matter of great concern. In this paper, above-mentioned uncertainty of the dynamic response characteristics of the building-appendage system to the spectrum-compatible artificial earthquake is investigated. (orig./RW)

Meta-analysis of digital game and study characteristics eliciting physiological stress responses.

Science.gov (United States)

van der Vijgh, Benny; Beun, Robbert-Jan; Van Rood, Maarten; Werkhoven, Peter

2015-08-01

Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We have therefore conducted a meta-analysis that analyzes the effects of characteristics of digital game stressors and study design on heart rate, systolic and diastolic blood pressure, in studies carried out from 1976 to 2012. In order to assess the differing quality between study designs, a new scale is developed and presented, coined reliability of effect size. The results show specific and consistent moderating functions of both game and study characteristics, on average accounting for around 43%, and in certain cases up to 57% of the variance found in physiological stress responses. Possible cognitive and physiological processes underlying these moderating functions are discussed, and a new model integrating these processes with the moderating functions is presented. These findings indicate that a digital game stressor does not act as a stressor by virtue of being a game, but rather derives its stressor function from its characteristics and the methodology in which it is used. This finding, together with the size of the associated moderations, indicates the need for a standardization of digital game stressors. © 2015 Society for Psychophysiological Research.

Accounting for the inertia of the thermocouples' measurements by modelling of a NPP Kalinin-3 transient with the coupled system code ATHLET-BIPR-VVER

International Nuclear Information System (INIS)

Nikonov, S.; Velkov, K.

2008-01-01

The ATHLET-BIPR-VVER coupled system code is applied for performing of safety analysis for different WWER reactors. During the last years its validation matrix is continuously being enlarged. The measurements performed during the commissioning phase of NPP Kalinin Unit 3 for the transient 'Switching-off of one Main Circulation Pump at nominal power' are very well documented and have a variety of recorded integral and local thermo-hydraulic and neutron-physic parameters including the measurements' errors. This data is being used for further validation of the coupled code system ATHLET-BIPR-VVER. In the paper are discussed the problems and our solutions by the correct interpretation of the measured thermocouples' records at NPP Kalinin-3 and the comparison with the predicted results by the coupled thermal-hydraulic/neutron-kinetic code ATHLET-BIPR-VVER. Of primary importance by such comparisons is the correct accounting of the fluid mixing process that take place in the surrounding of the measuring sensors and also the consideration of the time delay (inertia term) of the measuring devices. On the bases of previous experience and many simulations of the defined transient a method is discussed and proposed to consider correctly the inertia term of the thermocouples' measurements. The new modelling is implemented in the coupled system code ATHLET-BIPR-VVER for further validation. (Author)

Analysis and application of the response characteristics of DLL and LWD resistivity in horizontal well

Science.gov (United States)

Hu, Song; Li, Jun; Guo, Hong-Bo; Wang, Chang-Xue

2017-09-01

There exist different response characteristics in the resistivity measurements of dual laterolog (DLL) and logging while drilling (LWD) electromagnetic wave propagation logging in highly deviated and horizontal wells due to the difference in their measuring principles. In this study, we first use the integral equation method simulated the response characteristics of LWD resistivity and use the three dimensional finite element method (3D-FEM) simulated the response characteristics of DLL resistivity in horizontal wells, and then analyzed the response differences between the DLL and LWD resistivity. The comparative analysis indicated that the response differences may be caused by different factors such as differences in the angle of instrument inclination, anisotropy, formation interface, and mud intrusion. In the interface, the curves of the LWD resistivity become sharp with increases in the deviation while those of the DLL resistivity gradually become smooth. Both curves are affected by the anisotropy although the effect on DLL resistivity is lower than the LWD resistivity. These differences aid in providing a reasonable explanation in the horizontal well. However, this can also simultaneously lead to false results. At the end of the study, we explain the effects of the differences in the interpretation of the horizontal well based on the results and actual data analysis.

Synthesis of Room Impulse Responses for Variable Source Characteristics

Directory of Open Access Journals (Sweden)

M. Kunkemoeller

2011-01-01

Full Text Available Every acoustic source, e.g. a speaker, a musical instrument or a loudspeaker, generally has a frequency dependent characteristic radiation pattern, which is preeminent at higher frequencies. Room acoustic measurements nowadays only account for omnidirectional source characteristics. This motivates a measurement method that is capable of obtaining room impulse responses for these specific radiation patterns by using a superposition approach of several measurements with technically well-defined sound sources. We propose a method based on measurements with a 12-channel independentlydriven dodecahedron loudspeaker array rotated by an automatically controlled turntable.Radiation patterns can be efficiently described with the use of spherical harmonics representation. We propose a method that uses this representation for the spherical loudspeaker array used for the measurements and the target radiation pattern to be used for the synthesis.We show validating results for a deterministic test sound source inside in a small lecture hall.

Bronchodilator responsiveness as a phenotypic characteristic of established chronic obstructive pulmonary disease

DEFF Research Database (Denmark)

Albert, Paul; Agusti, Alvar; Edwards, Lisa

2012-01-01

Bronchodilator responsiveness is a potential phenotypic characteristic of chronic obstructive pulmonary disease (COPD). We studied whether change in lung function after a bronchodilator is abnormal in COPD, whether stable responder subgroups can be identified, and whether these subgroups experience...

Thermocouple and Infrared Sensor-Based Measurement of Temperature Distribution in Metal Cutting

Directory of Open Access Journals (Sweden)

Abdil Kus

2015-01-01

Full Text Available In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.

Thermocouple and Infrared Sensor-Based Measurement of Temperature Distribution in Metal Cutting

Science.gov (United States)

Kus, Abdil; Isik, Yahya; Cakir, M. Cemal; Coşkun, Salih; Özdemir, Kadir

2015-01-01

In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining. PMID:25587976

Developing and testing the CHORDS: Characteristics of Responsible Drinking Survey.

Science.gov (United States)

Barry, Adam E; Goodson, Patricia

2011-01-01

Report on the development and psychometric testing of a theoretically and evidence-grounded instrument, the Characteristics of Responsible Drinking Survey (CHORDS). Instrument subjected to four phases of pretesting (cognitive validity, cognitive and motivational qualities, pilot test, and item evaluation) and a final posttest implementation. Large public university in Texas. Randomly selected convenience sample (n  =  729) of currently enrolled students. This 78-item questionnaire measures individuals' responsible drinking beliefs, motivations, intentions, and behaviors. Cronbach α, split-half reliability, principal components analysis and Spearman ρ were conducted to investigate reliability, stability, and validity. Measures in the CHORDS exhibited high internal consistency reliability and strong correlations of split-half reliability. Factor analyses indicated five distinct scales were present, as proposed in the theoretical model. Subscale composite scores also exhibited a correlation to alcohol consumption behaviors, indicating concurrent validity. The CHORDS represents the first instrument specifically designed to assess responsible drinking beliefs and behaviors. It was found to elicit valid and reliable data among a college student sample. This instrument holds much promise for practitioners who desire to empirically investigate dimensions of responsible drinking.

Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

Energy Technology Data Exchange (ETDEWEB)

Takamura, S., E-mail: takamura@aitech.ac.jp [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Miyamoto, T. [Faculty of Engineering, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2013-07-15

The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component.

Thermal radiation characteristics and direct evidence of tungsten cooling on the way to nanostructure formation on its surface

International Nuclear Information System (INIS)

Takamura, S.; Miyamoto, T.; Ohno, N.

2013-01-01

The physical properties of tungsten with nanostructure on its surface are investigated focusing on the thermal radiation and cooling characteristics. First, direct evidence of substantial W surface cooling has been clearly shown with use of a very thin thermocouple inserted into W target, which solves an uncertainty associated with a radiation thermometer. Second, the above measurements of W surface temperature make it possible to estimate quantitatively the total emissivity from which we may evaluate the radiative power through the Stefan–Boltzmann equation, which is very important for mitigation evaluation of a serious plasma heat load to the plasma-facing component

The response characteristics of vibration-sensitive saccular fibers in the grassfrog, Rana temporaria

DEFF Research Database (Denmark)

Christensen-Dalsgaard, J; Jørgensen, M B

1988-01-01

The response characteristics of saccular nerve fibers in European grassfrogs (Rana temporaria) subjected to dorso-ventral, 10-200 Hz sinusoidal vibrations were studied. Only 4 fibers out of a total of 129 did not respond to the vibrations. 70 fibers had an irregular spontaneous activity of 2-48 s...... motion of the otolith relative to the macula is complex. No behavioral role of a vibration receptor has been demonstrated in the grassfrog.(ABSTRACT TRUNCATED AT 250 WORDS)......The response characteristics of saccular nerve fibers in European grassfrogs (Rana temporaria) subjected to dorso-ventral, 10-200 Hz sinusoidal vibrations were studied. Only 4 fibers out of a total of 129 did not respond to the vibrations. 70 fibers had an irregular spontaneous activity of 2......-48 spikes/s. These fibers were very vibration-sensitive. The synchronization thresholds at 10-20 Hz varied from below 0.005 to 0.02 cm/s2. In contrast to earlier results, all these fibers had low-pass characteristics (with respect to acceleration) and responded maximally at 10 and 20 Hz. 55 fibers had...

Meta-analysis of digital game and study characteristics eliciting physiological stress responses

NARCIS (Netherlands)

van der Vijgh, Benny; Beun, Robbert Jan; van Rood, Maarten; Werkhoven, Peter

2015-01-01

Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We

Attachment of Free Filament Thermocouples for Temperature Measurements on CMC

Science.gov (United States)

Lei, Jih-Fen; Cuy, Michael D.; Wnuk, Stephen P.

1997-01-01

Ceramic Matrix Composites (CMC) are being developed for use as enabling materials for advanced aeropropulsion engine and high speed civil transport applications. The characterization and testing of these advanced materials in hostile, high-temperature environments require accurate measurement of the material temperatures. Commonly used wire Thermo-Couples (TC) can not be attached to this ceramic based material via conventional spot-welding techniques. Attachment of wire TC's with commercially available ceramic cements fail to provide sufficient adhesion at high temperatures. While advanced thin film TC technology provides minimally intrusive surface temperature measurement and has good adhesion on the CMC, its fabrication requires sophisticated and expensive facilities and is very time consuming. In addition, the durability of lead wire attachments to both thin film TC's and the substrate materials requires further improvement. This paper presents a newly developed attachment technique for installation of free filament wire TC's with a unique convoluted design on ceramic based materials such as CMC's. Three CMC's (SiC/SiC CMC and alumina/alumina CMC) instrumented with type IC, R or S wire TC's were tested in a Mach 0.3 burner rig. The CMC temperatures measured from these wire TC's were compared to that from the facility pyrometer and thin film TC's. There was no sign of TC delamination even after several hours exposure to 1200 C. The test results proved that this new technique can successfully attach wire TC's on CMC's and provide temperature data in hostile environments. The sensor fabrication process is less expensive and requires very little time compared to that of the thin film TC's. The same installation technique/process can also be applied to attach lead wires for thin film sensor systems.

Dynamic response characteristics evaluation of hydrostatic bearing in hydraulic piston pump/motor

International Nuclear Information System (INIS)

Ham, Young Bog; Yun, So Nam; Kim, Dong Soo; Choi, Byoung Oh; Kim, Sung Dong

2001-01-01

In swash plate type axial piston hydraulic pump and motor, the piston shoe is periodically pressurized with square function shape by supply pressure load as rotation of cylinder barrel. Therefore the recess pressure ono bottom part of piston shoe is suddenly increase through orifice in the piston shoe. In this study, we simulated that the frequency response of the recess pressure against with change of supply pressure with analysis tool. Also, we evaluate the dynamic response characteristics of overbalanced hydrostatic bearing with change of the orifice diameter

Dynamic characteristics and structural response of the SWR 1000 under earthquake loading conditions

International Nuclear Information System (INIS)

Bielor, E.; Brettschuh, W.; Krutzik, N.J.; Tropp, R.

2001-01-01

Based on the conceptual design documentation of the SWR 1000 reactor building as well as specified representative seismological, and soil-dynamic input data, corresponding to prospective sites as a basis, the dynamic characteristics, as well as the in-structure dynamic response of the coupled vibrating structures have been elaborated. The structural design analysis was based on a 3-dimensional mathematical model of the building in which all details of the internal structures as well as the containment including the water in the pools were represented adequately. In order to demonstrate the influence of the soil-structure interaction effects on the dynamic response results, the soil was represented by two different assumptions. At first, considering the state of the art procedures, assuming frequency independent soil capabilities (equivalent stiffnesses and damping values), time domain calculations were carried out. In the second step, based on the frequency-dependency of the soil capabilities, frequency domain calculations were performed. The structural responses obtained by means of both procedures and the same mathematical model of the structures were evaluated and compared. The suitability of the preliminary design concept are discussed and the structural response results obtained on the basis of the bearing capacity and the stresses in the characteristic regions of the structure

A study on operators' cognitive response characteristics to the computerized working environment

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Hee; Lee, Jang Soo; Suh, Sang Moon; Lee, Hyun Cheol; Jung, Kwang Tae; Lee, Dhong Ha

1998-12-01

Although the introduction of computerized working environment to the nuclear facilities, the study on the human factors impacts of computers and automation has not been enough like the other industries. It is necessary to prepare the way to cope with the negative aspects in spite of many positive aspects of computerization in nuclear. This study is an empirical study including the survey of the human factor concerning, especially to the cognitive response of operators' and the experiments on the error proneness. At first, we survey the design and its changes of operator interface and interaction in nuclear power plants, and conclude five human factor issues. We discuss situation awareness issues as one of the major human factor concerning, and the assessment method. Secondly, a questionnaire and interviews survey to the operator's response characteristics are performed for possible criterion measures to the in-depth study on the cognitive characteristics. Finally, several experiments are conducted to test the error proneness. The issues and findings of this study could be utilized to any further study on the cognitive characteristic of operators to the computerized work environment.

The Catch-22 of responsible luxury: effects of luxury product characteristics on consumers' perception of fit with corporate social responsibility

OpenAIRE

Janssen, Catherine; Vanhamme, Joëlle; Lindgreen, Adam; Lefebvre, Cécile

2014-01-01

The notion of “responsible luxury” may appear as a contradiction in terms. This article investigates the influence of two defining characteristics of luxury products—scarcity and ephemerality—on consumers’ perception of the fit between luxury and corporate social responsibility (CSR), as well as how this perceived fit affects consumers’ attitudes toward luxury products. A field experiment reveals that ephemerality moderates the positive impact of scarcity on consumers’ perception of fit betwe...

Effect of Cetane Improver on Autoignition Characteristics of Low Cetane Sasol IPK Using Ignition Quality Tester (IQT)

Science.gov (United States)

2013-10-13

and deliver it into the chamber through an inward opening single-hole pintle-type injector nozzle . The needle is spring-loaded with a screw and a...direction. The first thermocouple measures the charge temperature close by the injector nozzle , the second thermocouple is 7 cm downstream from the... diesel engines. The ignition quality of a fuel is rated by its cetane number (CN) measured in a Cooperative Fuel Research (CFR) engine according to

Improvement of radiation response characteristic on CdTe detectors using fast neutron irradiation

International Nuclear Information System (INIS)

Miyamaru, Hiroyuki; Takahashi, Akito; Iida, Toshiyuki

1999-01-01

The treatment of fast neutron pre-irradiation was applied to a CdTe radiation detector in order to improve radiation response characteristic. Electron transport property of the detector was changed by the irradiation effect to suppress pulse amplitude fluctuation in risetime. Spectroscopic performance of the pre-irradiated detector was compared with the original. Additionally, the pre-irradiated detector was employed with a detection system using electrical signal processing of risetime discrimination (RTD). Pulse height spectra of 241 Am, 133 Ba, and 137 Cs gamma rays were measured to examine the change of the detector performance. The experimental results indicated that response characteristic for high-energy photons was improved by the pre-irradiation. The combination of the pre-irradiated detector and the RTD processing was found to provide further enhancement of the energy resolution. Application of fast neutron irradiation effect to the CdTe detector was demonstrated. (author)

Behavioral Fever Drives Epigenetic Modulation of the Immune Response in Fish.

Science.gov (United States)

Boltana, Sebastian; Aguilar, Andrea; Sanhueza, Nataly; Donoso, Andrea; Mercado, Luis; Imarai, Monica; Mackenzie, Simon

2018-01-01

Ectotherms choose the best thermal conditions to mount a successful immune response, a phenomenon known as behavioral fever. The cumulative evidence suggests that behavioral fever impacts positively upon lymphocyte proliferation, inflammatory cytokine expression, and other immune functions. In this study, we have explored how thermal choice during infection impacts upon underpinning molecular processes and how temperature increase is coupled to the immune response. Our results show that behavioral fever results in a widespread, plastic imprint on gene regulation, and lymphocyte proliferation. We further explored the possible contribution of histone modification and identified global associations between temperature and histone changes that suggest epigenetic remodeling as a result of behavioral fever. Together, these results highlight the critical importance of thermal choice in mobile ectotherms, particularly in response to an infection, and demonstrate the key role of epigenetic modification to orchestrate the thermocoupling of the immune response during behavioral fever.

New sensor for measurement of low air flow velocity. Phase I final report

International Nuclear Information System (INIS)

Hashemian, H.M.; Hashemian, M.; Riggsbee, E.T.

1995-08-01

The project described here is the Phase I feasibility study of a two-phase program to integrate existing technologies to provide a system for determining air flow velocity and direction in radiation work areas. Basically, a low air flow sensor referred to as a thermocouple flow sensor has been developed. The sensor uses a thermocouple as its sensing element. The response time of the thermocouple is measured using an existing in-situ method called the Loop Current Step Response (LCSR) test. The response time results are then converted to a flow signal using a response time-versus-flow correlation. The Phase I effort has shown that a strong correlation exists between the response time of small diameter thermocouples and the ambient flow rate. As such, it has been demonstrated that thermocouple flow sensors can be used successfully to measure low air flow rates that can not be measured with conventional flow sensors. While the thermocouple flow sensor developed in this project was very successful in determining air flow velocity, determining air flow direction was beyond the scope of the Phase I project. Nevertheless, work was performed during Phase I to determine how the new flow sensor can be used to determine the direction, as well as the velocity, of ambient air movements. Basically, it is necessary to use either multiple flow sensors or move a single sensor in the monitoring area and make flow measurements at various locations sweeping the area from top to bottom and from left to right. The results can then be used with empirical or physical models, or in terms of directional vectors to estimate air flow patterns. The measurements can be made continuously or periodically to update the flow patterns as they change when people and objects are moved in the monitoring area. The potential for using multiple thermocouple flow sensors for determining air flow patterns will be examined in Phase II

RESPONSE OF LANDUSE CHANGE ON HYDROLOGICAL CHARACTERISTICS OF WAY BETUNG WATERSHED - LAMPUNG

Directory of Open Access Journals (Sweden)

Zaenal Mubarok

2015-05-01

Full Text Available Change in landuse caused by a population increase from 114,973 people in 2007 to 134,792 people in 2012 (14.70% increased has influenced the hydrological characteristics of Way Betung watershed. The Soil and Water Assesment Tools (SWAT hydrological model could predict the hydrological characteristics influenced by the change in landuse. The aims of this study were: 1 to assess the impact of landuse change on hydrological characteristics; and, 2 to recommend the best landuse of Way Betung Watershed.The SWAT model was applied to simulate the change of landuse in Way Betung watershed. The effects of landuse change on the hydrological characteristics of Way Betung Watershed in 2001, 2006, and 2010 showed  the water yield of 874.66, 1047.70, and 774.04 mm respectively. The coefficient of surface runoff (C for those three years were 0.16, 0.31, and 0.23, whereas the coeficient of river regime were 30.65, 66.25, and 53.57 respectively. The application of agrotechnology on agricultural land and in line with the functions of forest area (scenario 4 gave the best response towards hydrological characteristics in the form of 709.69 mm of water yield with C being 0.14, whereas the coeficient of river regime value was 3.66. 

Characteristics of Jerk Response Spectra for Elastic and Inelastic Systems

Directory of Open Access Journals (Sweden)

Haoxiang He

2015-01-01

Full Text Available Jerk is the time rate of acceleration and mainly represents the nonstationary component in high frequency band of the earthquake wave. The study on jerk and its response spectra can enhance the recognition of the nonstationary ground motion. The mechanical meaning and research value of jerk are described. Jerk is recommended to be solved by establishing state-space equations and Runge-Kutta method. The solution method of elastic and inelastic jerk response spectra under ground motion is established, and the accurate jerk spectrum should be calculated directly according to numerical computing instead of pseudo-acceleration spectrum. The characteristics of jerk response spectra are studied according to the influencing factors, such as site condition, amplification factor, ductility factor, and reduction factor. The concept of impact reduction factor is presented. The statistical results show that the jerk spectrum has similar rules as the acceleration spectrum, and the amplitude is relative to the predominant period, especially for structures with short or medium period. If the ductility is improved, the effective jerk will reduce obviously, and the impact reduction factor will be enhanced. Different from the strength reduction factor, the impact reduction factor is nearly not relevant to the period.

Identifying the relevant dependencies of the neural network response on characteristics of the input space

CERN Multimedia

CERN. Geneva

2018-01-01

This talk presents an approach to identify those characteristics of the neural network inputs that are most relevant for the response and therefore provides essential information to determine the systematic uncertainties.

Construção e avaliação de psicrômetro aspirado de termopar Construction and evaluation of an aspirated thermocouple psychrometer

Directory of Open Access Journals (Sweden)

Fábio Ricardo Marin

2001-12-01

Full Text Available Construiu-se um psicrômetro de termopar aspirado, de baixo custo e fácil utilização em sistemas automáticos de aquisição de dados, utilizando-se tubos de PVC. A aspiração foi feita por ventiladores utilizados em microcomputadores e as temperaturas foram determinadas com junções de termopar de cobre-constantan. Para umidecimento do bulbo, utilizou-se um cordão de algodão. Os resultados da comparação com higrômetro capacitivo Vaisala Inc. e com psicrômetro aspirado tipo Assman mostraram que tanto em ambientes naturais como em controlados, a precisão e a exatidão das medidas foi muito boa, de maneira que o psicrômetro aqui descrito pode ser empregado para determinação da pressão atual de vapor e da umidade relativa sem perda de qualidade dos dados, e também em estudos que levem em conta gradientes de temperatura e umidade específica.The construction of a low cost aspirated thermocouple psychrometer made of PVC tubes is described. The instrument can easily be connected to dataloggers. The aspiration is made by fans used in microcomputers and temperatures measured with cooper-constantan thermocouples. A cotton string was used to make the wet junction. Its perfomance was evaluated in comparison to an Assman aspirated psychrometer and a Vaisala Inc. capacitive higrometer, in natural and controlled environments. The results show a good agreement between measures, allowing air vapour, relative humidity, temperature and specific humidity gradients to be determined using the proposed psychrometer.

Dynamic response characteristics of steel portal frames having semi-rigid joints under sinusoidal wave excitation

Science.gov (United States)

Bhatti, Abdul Qadir

2017-12-01

To demonstrate the characteristics of the nonlinear response of steel frames, an elastic dynamic response analysis of the semi-rigid frame is performed under the harmonic wave. The semi-rigid contact is represented by the alternating spring which is given stiffness by a three-parameter energy model which approaches the hysterical curve by hardening model. The properties of spectra and hysteric curves are presented. This study shows that (1) the greater the acceleration input capacitance the smaller the instant connection capability and the smaller is the response. (2) However, by allowing an extreme increase in capacitance input acceleration, response spectra can be increased as the contact stiffness results near zero.

Comparison of Response Characteristics of High-Purity Germanium Detectors using Analog Versus Digital Processing

International Nuclear Information System (INIS)

Luke, S J; Raschke, K

2004-01-01

In this article we will discuss some of the results of the response characteristics of High Purity germanium detectors using analog versus digital processing of the signals that are outputted from the detector. The discussion will focus on whether or not there is a significant difference in the response of the detector with digital electronics that it limits the ability of the detection system to get reasonable gamma ray spectrometric results. Particularly, whether or not the performance of the analysis code Pu600 is compromised

Characteristics of Effective Collaboration in Response to Diversified Transportation Planning Authority

Directory of Open Access Journals (Sweden)

John S. Miller

2011-01-01

Full Text Available Advantages of decentralized transportation planning responsibilities may include reduced project delivery cost, the integration of comprehensive long-range planning with regional land use, and greater accountability regarding local concerns. Yet disadvantages may include a tendency for operations to dominate longer-term planning, inconsistent operational standards, and difficulty in achieving network benefits, since some transportation links may provide benefits to the entire system but not to the immediate area where the link is located. To surmount these challenges in a decentralized environment, agencies need to cooperate effectively. Characteristics of effective collaboration include (1 experienced personnel, (2 credibility of the deciding entity, (3 transparency of decision-making processes, (4 an authority with sufficient power and/or funding to encourage implementation of key initiatives, (5 clear incentives for cooperation, and, of special importance given limited resources, and (6 an ability to evaluate tradeoffs. An access management case study demonstrates how agencies may use these characteristics to advance challenging projects in a decentralized environment.

Temperature measurement in the liquid helium range at pressure

International Nuclear Information System (INIS)

Itskevich, E.S.; Krajdenov, V.F.

1978-01-01

The use of bronze and germanium resistance thermometers and the use of a (Au + 0.07 % Fe)-Cu thermocouple for temperature measurements from 1.5 to 4.2 K in the hydrostatic compression of up to 10 kbar are considered. To this aim, the thermometer resistance as a function of temperature and pressure is measured. It is revealed that pressure does not change the thermometric response of the bronze resistance thermometer but only shifts it to the region of lower temperatures. The identical investigations of the germanium resistance thermometer shows that strong temperature dependence and the shift of its thermometric response under the influence of pressure make the use of germanium resistance thermometers in high-pressure chambers very inconvenient. The results of the analysis of the (Au + 0.07 % Fe) - Cu thermocouple shows that with a 2 per cent accuracy the thermocouple Seebeck coefficient does not depend on pressure. It permits to use this thermocouple for temperature measurements at high pressures

Heat Transfer Characteristics of a Focused Surface Acoustic Wave (F-SAW Device for Interfacial Droplet Jetting

Directory of Open Access Journals (Sweden)

Donghwi Lee

2018-06-01

Full Text Available In this study, we investigate the interfacial droplet jetting characteristics and thermal stability of a focused surface acoustic wave device (F-SAW. An F-SAW device capable of generating a 20 MHz surface acoustic wave by applying sufficient radio frequency power (2–19 W on a 128°-rotated YX-cut piezoelectric lithium niobate substrate for interfacial droplet jetting is proposed. The interfacial droplet jetting characteristics were visualized by a shadowgraph method using a high-speed camera, and a heat transfer experiment was conducted using K-type thermocouples. The interfacial droplet jetting characteristics (jet angle and height were analyzed for two different cases by applying a single interdigital transducer and two opposite interdigital transducers. Surface temperature variations were analyzed with radio frequency input power increases to evaluate the thermal stability of the F-SAW device in air and water environments. We demonstrate that the maximum temperature increase of the F-SAW device in the water was 1/20 of that in the air, owing to the very high convective heat transfer coefficient of the water, resulting in prevention of the performance degradation of the focused acoustic wave device.

Variation in C - reactive protein response according to host and mycobacterial characteristics in active tuberculosis

OpenAIRE

Brown, James; Clark, Kristina; Smith, Colette; Hopwood, Jennifer; Lynard, Oliver; Toolan, Michael; Creer, Dean; Barker, Jack; Breen, Ronan; Brown, Tim; Cropley, Ian; Lipman, Marc

2016-01-01

Background The C - reactive protein (CRP) response is often measured in patients with active tuberculosis (TB) yet little is known about its relationship to clinical features in TB, or whether responses differ between ethnic groups or with different Mycobacterium tuberculosis (M.tb) strain types. We report the relationship between baseline serum CRP prior to treatment and disease characteristics in a metropolitan population with TB resident in a low TB incidence region. Methods People treated...

Study on time characteristics of fast time response inorganic scintillator CeF3

International Nuclear Information System (INIS)

Hu Mengchun; Zhou Dianzhong; Guo Cun; Ye Wenying

2003-01-01

The cerium fluoride (CeF 3 ) is a kind of new fast time response inorganic scintillator. The physical characteristics of CeF 3 are well suitable for detection of domestic pulse γ-rays. The time response of detector composed by phototube with CeF 3 are measured by use of the pulse radiation source with rise time about 0.8 ns, and FWHM time 1.5-2.2 ns. Experiment results show that the rise time is less than 2 ns, FWHM time is about 10 ns, fall time is about 60 ns, average decay time constant is 20-30 ns, respectively for CeF 3

A mathematical model of heat flow in a thermopile for measuring muscle heat production: implications for design and signal analysis.

Science.gov (United States)

Barclay, C J

2015-09-01

Contracting muscles produce heat which largely arises from the biochemical reactions that provide the energy for contraction. Measurements of muscle heat production have made, and continue to make, important contributions to our understanding of the bases of contraction. Most measurements of muscle heat production are made using a thermopile, consisting of a series of thermocouples arranged so that alternate thermocouples are in thermal contact with the muscle and with an isothermal reference. In this study, a mathematical model was constructed of a muscle lying on a thermopile consisting of antimony-bismuth thermocouples sandwiched between polymer sheets. The validity of the model was demonstrated by its ability to accurately predict thermopile outputs in response to applying heat to the thermopile surface, to generating heat in the thermocouples using the Peltier effect and to adding heat capacity on the thermopile surface. The model was then used to show how practical changes to thermopile construction could minimise response time and thermopile heat capacity and allow measurement of very low rates of heat production. The impulse response of a muscle-thermopile system was generated using the model and used to illustrate how a measured signal can be deconvolved with the impulse response to correct for lag introduced by the thermopile.

Spray and Combustion Characteristics of a Novel Multi-circular Jet Plate in Air-assisted Atomizer

Directory of Open Access Journals (Sweden)

Hisham Amirnordin Shahrin

2017-01-01

Full Text Available Atomization of liquid fuel in air-assisted atomizer is highly dependent on air mixing, which can be enhanced using turbulent generators, such as multi-circular jet (MCJ plates and swirler. This study aims to determine the effects of novel MCJ plates on the spray and combustion characteristics of an air-assisted atomizer by evaluating spray and flame parameters, such as penetration length, cone angle, and cone area. MCJ 30 and MCJ 45, with inclined jets at 30° and 45°, respectively, were used in the experiment. A swirler was also used for comparison. The spray and flame images were recorded at different equivalence ratios through direct photography and analyzed using image J software. Flame temperature was determined using a thermal infrared camera, and burning chamber and flue gas temperatures were measured using thermocouples. The spray and flame characteristics of MCJ 30 exhibited performance comparable with those of the MCJ 45 and swirler. The integration of turbulence and swirling motion concept into the novel MCJ plates can enhance the mixing formation and thus improve the performance of burner combustion.

National Characteristics of Emergency Medical Services Responses for Older Adults in the United States.

Science.gov (United States)

Duong, Hieu V; Herrera, Lauren Nicholas; Moore, Justin Xavier; Donnelly, John; Jacobson, Karen E; Carlson, Jestin N; Mann, N Clay; Wang, Henry E

2018-01-01

Older adults, those aged 65 and older, frequently require emergency care. However, only limited national data describe the Emergency Medical Services (EMS) care provided to older adults. We sought to determine the characteristics of EMS care provided to older adults in the United States. We used data from the 2014 National Emergency Medical Services Information System (NEMSIS), encompassing EMS response data from 46 States and territories. We excluded EMS responses for children older adults as age ≥65 years. We compared patient demographics (age, sex, race, primary payer), response characteristics (dispatch time, location type, time intervals), and clinical course (clinical impression, injury, procedures, medications) between older and younger adult EMS emergency 9-1-1 responses. During the study period there were 20,212,245 EMS emergency responses. Among the 16,116,219 adult EMS responses, there were 6,569,064 (40.76%) older and 9,547,155 (59.24%) younger adults. Older EMS patients were more likely to be white and the EMS incident to be located in healthcare facilities (clinic, hospital, nursing home). Compared with younger patients, older EMS patients were more likely to present with syncope (5.68% vs. 3.40%; OR 1.71; CI: 1.71-1.72), cardiac arrest/rhythm disturbance (3.27% vs. 1.69%; OR 1.97; CI: 1.96-1.98), stroke (2.18% vs. 0.74%; OR 2.99; CI: 2.96-3.02) and shock (0.77% vs. 0.38%; OR 2.02; CI: 2.00-2.04). Common EMS interventions performed on older persons included intravenous access (32.02%), 12-lead ECG (14.37%), CPR (0.87%), and intubation (2.00%). The most common EMS drugs administered to older persons included epinephrine, atropine, furosemide, amiodarone, and albuterol or ipratropium. One of every three U.S. EMS emergency responses involves older adults. EMS personnel must be prepared to care for the older patient.

How are streamflow responses to the El Nino Southern Oscillation affected by watershed characteristics?

Science.gov (United States)

Rice, Joshua S.; Emanuel, Ryan E.

2017-05-01

Understanding the factors that influence how global climate phenomena, such as the El-Nino Southern Oscillation (ENSO), affect streamflow behavior is an important area of research in the hydrologic sciences. While large-scale patterns in ENSO-streamflow relationships have been thoroughly studied, and are relatively well-understood, information is scarce concerning factors that affect variation in ENSO responses from one watershed to another. To this end, we examined relationships between variability in ENSO activity and streamflow for 2731 watersheds across the conterminous U.S. from 1970 to 2014 using a novel approach to account for the intermediary role of precipitation. We applied an ensemble of regression techniques to describe relationships between variability in ENSO activity and streamflow as a function of watershed characteristics including: hydroclimate, topography, geomorphology, geographic location, land cover, soil characteristics, bedrock geology, and anthropogenic influences. We found that variability in watershed scale ENSO-streamflow relationships was strongly related to factors including: precipitation timing and phase, forest cover, and interactions between watershed topography and geomorphology. These, and other influential factors, share in common the ability to affect the partitioning and movement of water within watersheds. Our results demonstrate that the conceptualization of watersheds as signal filters for hydroclimate inputs, commonly applied to short-term rainfall-runoff responses, also applies to long-term hydrologic responses to sources of recurrent climate variability. These results also show that watershed processes, which are typically studied at relatively fine spatial scales, are also critical for understanding continental scale hydrologic responses to global climate.

Multi-Objective Demand Response Model Considering the Probabilistic Characteristic of Price Elastic Load

Directory of Open Access Journals (Sweden)

Shengchun Yang

2016-01-01

Full Text Available Demand response (DR programs provide an effective approach for dealing with the challenge of wind power output fluctuations. Given that uncertain DR, such as price elastic load (PEL, plays an important role, the uncertainty of demand response behavior must be studied. In this paper, a multi-objective stochastic optimization problem of PEL is proposed on the basis of the analysis of the relationship between price elasticity and probabilistic characteristic, which is about stochastic demand models for consumer loads. The analysis aims to improve the capability of accommodating wind output uncertainty. In our approach, the relationship between the amount of demand response and interaction efficiency is developed by actively participating in power grid interaction. The probabilistic representation and uncertainty range of the PEL demand response amount are formulated differently compared with those of previous research. Based on the aforementioned findings, a stochastic optimization model with the combined uncertainties from the wind power output and the demand response scenario is proposed. The proposed model analyzes the demand response behavior of PEL by maximizing the electricity consumption satisfaction and interaction benefit satisfaction of PEL. Finally, a case simulation on the provincial power grid with a 151-bus system verifies the effectiveness and feasibility of the proposed mechanism and models.

Dynamic response characteristics analysis of the doubly-fed wind power system under grid voltage drop

Science.gov (United States)

Chen, Y.; Wang, J.; Wang, H. H.; Yang, L.; Chen, W.; Xu, Y. T.

2016-08-01

Double-fed induction generator (DFIG) is sensitive to the disturbances of grid, so the security and stability of the grid and the DFIG itself are under threat with the rapid increase of DFIG. Therefore, it is important to study dynamic response of the DFIG when voltage drop failure is happened in power system. In this paper, firstly, mathematical models and the control strategy about mechanical and electrical response processes is respectively introduced. Then through the analysis of response process, it is concluded that the dynamic response characteristics are related to voltage drop level, operating status of DFIG and control strategy adapted to rotor side. Last, the correctness of conclusion is validated by the simulation about mechanical and electrical response processes in different voltage levels drop and different DFIG output levels under DIgSILENT/PowerFactory software platform.

Relationships between response surfaces for tablet characteristics of placebo and API-containing tablets manufactured by direct compression method.

Science.gov (United States)

Hayashi, Yoshihiro; Tsuji, Takahiro; Shirotori, Kaede; Oishi, Takuya; Kosugi, Atsushi; Kumada, Shungo; Hirai, Daijiro; Takayama, Kozo; Onuki, Yoshinori

2017-10-30

In this study, we evaluated the correlation between the response surfaces for the tablet characteristics of placebo and active pharmaceutical ingredient (API)-containing tablets. The quantities of lactose, cornstarch, and microcrystalline cellulose were chosen as the formulation factors. Ten tablet formulations were prepared. The tensile strength (TS) and disintegration time (DT) of tablets were measured as tablet characteristics. The response surfaces for TS and DT were estimated using a nonlinear response surface method incorporating multivariate spline interpolation, and were then compared with those of placebo tablets. A correlation was clearly observed for TS and DT of all APIs, although the value of the response surfaces for TS and DT was highly dependent on the type of API used. Based on this knowledge, the response surfaces for TS and DT of API-containing tablets were predicted from only two and four formulations using regression expression and placebo tablet data, respectively. The results from the evaluation of prediction accuracy showed that this method accurately predicted TS and DT, suggesting that it could construct a reliable response surface for TS and DT with a small number of samples. This technique assists in the effective estimation of the relationships between design variables and pharmaceutical responses during pharmaceutical development. Copyright © 2017 Elsevier B.V. All rights reserved.

Characteristics of infrared thermometers manufactured in Japan and calibration methods for sky radiant emittance

International Nuclear Information System (INIS)

Wang, X.; Horiguchi, I.; Machimura, T.

1993-01-01

Infrared thermometers to measure surface temperature have been increasingly adopted in recent years. The characteristics of the IR thermometer, however, are not well known.IR thermometers manufactured in Japan systematically adjust for ambient radiation based on the internal temperature of the thermometer. If, therefore, there is a large difference between the internal temperature of the IR thermometer and the apparent temperature associated with the surrounding radiation, a large error will be induced into the measured surface temperature.The purpose of our research was to determine the characteristics and measurement errors of IR thermometers. Experiments were performed with regard to the following items: (1) Measurement errors related to the internal temperature of the IR thermometer. (2) Linearity of the output signal of the IR thermometer. (3) Response of the output signal to changes in the emissivity setting. (4) Effect of sky radiant emittance on the measured surface temperature. (5) Calibration method for the terrestrial surface.The following is a summary of the results: Measurement error is affected by the internal temperature of the IR thermometer. Measurement accuracy is improved with a controlled internal temperature of 20-30°C. The measurement error becomes larger at emissivity settings under 0.7.The measurement error outdoors was not proportional to the downward longwave radiation, but to the sky radiant temperature measured by the IR thermometer. Calibration for sky radiant emittance was improved by using the difference between sky radiant temperature and air temperature.When the surface temperature measured by the infrared thermometer is plotted against the surface temperature measured by thermocouple, the sky radiant emittance error is obtained from the Y intercept. Additionally, the difference between true temperature and output of the IR thermometer for a reference plate was compared to that obtained for vegetation, and the RMS obtained was

The analysis of dynamic characteristics and wind-induced displacement response of space Beam String Structure

Directory of Open Access Journals (Sweden)

Chen Yong Jian

2018-01-01

Full Text Available The Beam String Structure structural system, also called BSS, has the advantages of lighter dead weight and greater flexibility. The wind load is the main design control factor. The dynamic characteristics and wind-induced displacement response of BSS are studied by the finite element method. The roof structure of the stadium roof of the Fuzhou Olympic Sports Center is the engineering background. 1The numerical model was built by ANSYS, by shape finding, determine the initial stress state of structural members such as external cables; 2From the analysis of dynamic characteristics, the main mode of vibration is the vibration of cables; 3The wind speed spectrum of MATLAB generation structure is obtained by AR method, the structural response of the structure under static wind load and fluctuating wind load is calculated. From the analysis result, considering the equivalent static wind load of BSS , the design of adverse wind is not safe, and the fluctuating wind load should be taken into account.

Thin film thermocouples for in situ membrane electrode assembly temperature measurements in a polybenzimidazole-based high temperature proton exchange membrane unit cell

DEFF Research Database (Denmark)

Ali, Syed Talat; Lebæk, Jesper; Nielsen, Lars Pleth

2010-01-01

m thick layer of TFTCs on 75 mu m thick Kapton foil. The Kapton foil was treated with in situ argon plasma etching to improve the adhesion between TFTCs and the Kapton substrate. The TFTCs were covered with a 7 mu m liquid Kapton layer using spin coating technique to protect them from environmental......This paper presents Type-T thin film thermocouples (TFTCs) fabricated on Kapton (polyimide) substrate for measuring the internal temperature of PBI(polybenzimidazole)-based high temperature proton exchange membrane fuel cell (HT-PEMFC). Magnetron sputtering technique was employed to deposit a 2 mu...... degradation. This Kapton foil with deposited TFTCs was used as sealing inside a PBI (polybenzimidazole)-based single cell test rig, which enabled measurements of in situ temperature variations of the working fuel cell MEA. The performance of the TFTCs was promising with minimal interference to the operation...

Epidemiological and Clinical Baseline Characteristics as Predictive Biomarkers of Response to Anti-VEGF Treatment in Patients with Neovascular AMD

Directory of Open Access Journals (Sweden)

Miltiadis K. Tsilimbaris

2016-01-01

Full Text Available Purpose. To review the current literature investigating patient response to antivascular endothelial growth factor-A (VEGF therapy in the treatment of neovascular age-related macular degeneration (nAMD and to identify baseline characteristics that might predict response. Method. A literature search of the PubMed database was performed, using the keywords: AMD, anti-VEGF, biomarker, optical coherence tomography, treatment outcome, and predictor. The search was limited to articles published from 2006 to date. Exclusion criteria included phase 1 trials, case reports, studies focusing on indications other than nAMD, and oncology. Results. A total of 1467 articles were identified, of which 845 were excluded. Of the 622 remaining references, 47 met all the search criteria and were included in this review. Conclusion. Several baseline characteristics correlated with anti-VEGF treatment response, including best-corrected visual acuity, age, lesion size, and retinal thickness. The majority of factors were associated with disease duration, suggesting that longer disease duration before treatment results in worse treatment outcomes. This highlights the need for early treatment for patients with nAMD to gain optimal treatment outcomes. Many of the identified baseline characteristics are interconnected and cannot be evaluated in isolation; therefore multivariate analyses will be required to determine any specific relationship with treatment response.

The effect of seismic motion characteristics on the inelastic response reduction of cylindrical shell structures

International Nuclear Information System (INIS)

Hagiwara, Y.; Yamamoto, K.; Akiyama, H.

1993-01-01

Reactor vessels of FBR are cylindrical shell structures, whose critical failure mode during earthquakes is plastic buckling in shear or bending mode. In buckling prevention of the vessels, it is of primary importance to realistically evaluate the plastic response reduction effect in the pre-buckling stage. Though the authors have already proposed a empirical formula to estimate the response reduction effect, the formula depends only on the pre-buckling ductility factor in the evaluation for the purpose of easy design practice. In this study, the effect of seismic motion characteristics on the response reduction effect was investigated both experimentally and numerically, and a improved version of the empirical expression of the reduction factor was proposed. In this new method, the response reduction effect is evaluated by an initial acceleration amplification factor in addition to the ductility of structures. (author)

High-LET dose-response characteristics by track structure theory of heavy charged particles

International Nuclear Information System (INIS)

Hansen, J.W.; Olsen, K.J.

1981-09-01

The track structure theory developed by Katz and co-workers ascribes the effect of high-LET radiation to the highly inhomogeneous dose distribution due to low energy Δ-rays ejected from the particle track. The theory predicts the effectiveness of high-LET radiation by using the ion parameters zsub(eff') effective charge of the ion, and β = v/c, the relative ion velocity, together with the characteristic dose D 37 derived from low-LET dose-response characteristic of the detector and the approximate size asub(0) of the sensitive element of the detector. 60 Co gamma-irradiation is used as a reference low-LET radiation, while high-LET radiation ranging from 16 MeV protons to 4 MeV/amu 16 0-ions covering an initial LET range of 30-5500 MeVcm 2 /g is obtained from a tandem Van de Graaff accelerator. A thin film (5mg/cm 2 ) radiochromic dye cyanide plastic dosemeter was used as detector with the characteristic dose of 16.8 Mrad and a sensitive element size of 10 -7 cm. Theoretical and experimental effectiveness, RBE, agreed within 10 to 25% depending on LET. (author)

Perceived neighborhood characteristics predict severity and emotional response to daily stressors.

Science.gov (United States)

Scott, Stacey B; Munoz, Elizabeth; Mogle, Jacqueline A; Gamaldo, Alyssa A; Smyth, Joshua M; Almeida, David M; Sliwinski, Martin J

2018-03-01

Neighborhood characteristics may influence health and well-being outcomes through stressors in daily life. This study tested whether a varied set of perceived characteristics of neighborhood (i.e., social cohesion, safety, aesthetic quality, violence) predicted stressor frequency and severity as well as negative emotional responses to stressors. We predicted greater reported cohesion and safety and less violence would be associated with less frequent stressor exposure and severity and less intense negative affect following stressors; we conducted subsequent tests of neighborhood aesthetic quality as a predictor. Participants (n = 233, age 25-65 years) were residents in a socio-economically, racially, and ethnically diverse zip code in Bronx, New York, most who participated in the Effects of Stress on Cognitive Aging, Physiology and Emotion study between 2012 and 2013. They provided demographic information and neighborhood ratings, then participated in the EMA protocol in which they completed brief smartphone surveys of current negative affect and stressor exposure, severity, and recency, five times daily for 14 days. No coded neighborhood characteristic was related to the frequency of stressors. Individuals who reported greater neighborhood violence, however, rated their stressors as more severe. Individuals rating their neighborhood lower in safety or aesthetic quality, or higher in violence, had greater negative affect following stressors. Even among people living within the same zip code, individual differences in perceptions of neighborhood predict how stressful they appraised stressors in daily life to be and how much negative affect they reported following stressors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristics of the excavation response zone as applied to shaft sealing

International Nuclear Information System (INIS)

Jakubick, A.T.; Klein, R.; Gray, M.N.; Keil, L.D.

1989-01-01

Effective sealing of an underground repository requires high quality seals. Clay-based backfills in combination with cement plugs are the possible candidates. An important component of the shaft sealing program is the development of techniques to predict and monitor the flow in the excavation response zone (ERZ) and at the seal-rock interface. The mechanical and hydraulic performance of the seal and backfill and the flow characteristics of the ERZ under in situ conditions will be tested in three experimental shafts to be excavated in the URL. The use of the vacuum permeability technique for characterization of the hydraulic properties and of the permeability distribution in the ERZ under various geomechanical conditions is discussed

Flow characteristics and heat transfer performances of a semi-confined impinging array of jets: effect of nozzle geometry

Energy Technology Data Exchange (ETDEWEB)

Dano, B.P.E.; Liburdy, J.A. [Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering; Kanokjaruvijit, Koonlaya [Imperial College, London (United Kingdom). Dept. of Mechanical Engineering

2005-02-01

The flow and heat transfer characteristics of confined jet array impingement with crossflow is investigated. Discrete impingement pressure measurements are used to obtain the jet orifice discharge flow coefficient. Digital particle image velocimetry (DPIV) and flow visualization are used to determine the flow characteristics. Two thermal boundary conditions at the impinging surface are presented: an isothermal surface, and a uniform heat flux, where thermocouple and thermochromic liquid crystal methods were used, respectively, to determine the local heat transfer coefficient. Two nozzle geometries are studied, circular and cusped ellipse. Based on the interaction with the jet impingement at the surface, the crossflow is shown to influence the heat transfer results. The two thermal boundary conditions differ in overall heat transfer correlation with the jet Reynolds number. Detailed velocity data show that the flow development from the cusped ellipse nozzle affects the wall region flow more than the circular nozzle, as influenced by the crossflow interactions. The overall heat transfer for the uniform heat flux boundary condition is found to increase for the cusped ellipse orifice. (Author)

Uncertainty analysis of thermal quantities measurement in a centrifugal compressor

Science.gov (United States)

Hurda, Lukáš; Matas, Richard

2017-09-01

Compressor performance characteristics evaluation process based on the measurement of pressure, temperature and other quantities is examined to find uncertainties for directly measured and derived quantities. CFD is used as a tool to quantify the influences of different sources of uncertainty of measurements for single- and multi-thermocouple total temperature probes. The heat conduction through the body of the thermocouple probe and the heat-up of the air in the intake piping are the main phenomena of interest.

Study on heat transfer characteristics in a mixing tee pipe to evaluate for thermal fatigue

International Nuclear Information System (INIS)

Miyoshi, Koji; Nakamura, Akira; Utanohara, Yoichi

2016-01-01

Thermal fatigue racking may initiate at a tee pipe where high and low temperature fluids flow in from different directions and mix. Thermal stress fluctuations are caused by movement of a hot spot on the pipe inner surface. It is important to investigate the heat transfer from the fluid to the structure around the hot spot. The heat transfer characteristic in the mixing tee pipe was investigated by tests in this study. The unsteady heat transfer coefficients around the hot spot were estimated with the fluid and wall temperature, which were measured with thermocouples. The estimated heat transfer coefficient varied from 1.2 to 3.5 times of the steady state heat transfer coefficient. The heat transfer coefficient was 2.9 times of the steady state value at the position for the maximum stress fluctuation, which was calculated with the measured wall temperature distribution. (author)

The response of land-falling tropical cyclone characteristics to projected climate change in northeast Australia

Science.gov (United States)

Parker, Chelsea L.; Bruyère, Cindy L.; Mooney, Priscilla A.; Lynch, Amanda H.

2018-01-01

Land-falling tropical cyclones along the Queensland coastline can result in serious and widespread damage. However, the effects of climate change on cyclone characteristics such as intensity, trajectory, rainfall, and especially translation speed and size are not well-understood. This study explores the relative change in the characteristics of three case studies by comparing the simulated tropical cyclones under current climate conditions with simulations of the same systems under future climate conditions. Simulations are performed with the Weather Research and Forecasting Model and environmental conditions for the future climate are obtained from the Community Earth System Model using a pseudo global warming technique. Results demonstrate a consistent response of increasing intensity through reduced central pressure (by up to 11 hPa), increased wind speeds (by 5-10% on average), and increased rainfall (by up to 27% for average hourly rainfall rates). The responses of other characteristics were variable and governed by either the location and trajectory of the current climate cyclone or the change in the steering flow. The cyclone that traveled furthest poleward encountered a larger climate perturbation, resulting in a larger proportional increase in size, rainfall rate, and wind speeds. The projected monthly average change in the 500 mb winds with climate change governed the alteration in the both the trajectory and translation speed for each case. The simulated changes have serious implications for damage to coastal settlements, infrastructure, and ecosystems through increased wind speeds, storm surge, rainfall, and potentially increased size of some systems.

Role of growth temperature on the frequency response characteristics of pentacene-based organic devices

International Nuclear Information System (INIS)

Shao, Yayun; Zhang, Yang; He, Wenqiang; Wu, Sujuan; Zeng, Min; Zhang, Zhang; Gao, Xingsen; Lu, Xubing; Liu, J-M; Liu, Chuan; Minari, Takeo

2015-01-01

The ac frequency response characteristics (FRC) of organic thin film transistors and metal-insulator semiconductor diodes were highly improved by controlling the morphology and electrical characteristics of semiconducting pentacene films. The devices with films grown at 50 °C show much higher cutoff frequency and better frequency stability of flat-band voltage, as compared to those with films grown at other temperatures below or above. The improvement mainly originates from the maximum field effect carrier mobility of 0.78 cm 2 V −1 s −1 and a small metal/organic contact resistance (R c ) obtained in the optimum thin film transistors. Our results indicate growth temperature precisely tunes the film microstructure and metal/semiconductor interface, which together determine the FRC of pentacene-based organic devices. (paper)

Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop

International Nuclear Information System (INIS)

McCulloch, R.W.; MacPherson, R.E.

1983-03-01

The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm 2 , 1000 0 C cladding temperature, and (2) 40 h at 40 W/cm 2 , 1200 0 C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370 0 C

Board characteristics and corporate social responsibility disclosure in the Jordanian banks

Directory of Open Access Journals (Sweden)

Mohammad Ahid Ghabayen

2016-02-01

Full Text Available This paper aims to examine the impact of board characteristics on the level of corporate social responsibility disclosure (CSRD in the Jordanian banking sector for a sample of 147 banks/years during a period of 10 years (2004-2013. A checklist consisting of 100 items is developed to measure the disclosure level and the result indicates a relatively low level of disclosure in Jordanian banks. Multiple regression analysis is employed to examine the developed hypotheses. The results indicated that the larger board size and higher level of disclosure are correlated. However, low level of disclosure is associated to higher proportion of independent directors and institutional directors. In addition, female director is found to negatively affect the level of disclosure. This study has filled some of the previous studies’ gaps; the study is conducted in a new business environment. Besides, previous CSRD’s studies have not considered some of the board characteristics such as institutional directors. Thus this study investigates their impacts on the level of CSRD. In addition, this study provides some guidelines for the future works. Furthermore, the findings of this study might be interested to several groups of shareholders and stakeholders such as government, regulators, potential investors and CSR agencies.

The influence of provider characteristics and market forces on response to financial incentives.

Science.gov (United States)

O'Neil, Brock; Tyson, Mark; Graves, Amy J; Barocas, Daniel A; Chang, Sam S; Penson, David F; Resnick, Matthew J

2017-11-01

Alternative payment models, such as accountable care organizations, use financial incentives as levers for change to facilitate the transition from volume to value. However, implementation raises concerns about adverse changes in market competition and the resultant physician response. We sought to identify physician characteristics and market-level factors associated with variation in response to financial incentives for cancer care that may ultimately be leveraged in risk-shared payment models. Retrospective cohort study of physicians providing minimally invasive bladder cancer procedures to fee-for-service Medicare beneficiaries. We examined the relationship of between-group differences in market-level factors (competition [Herfindahl-Hirschman Index (HHI)] and provider density) and physician-level factors (use of unique billing codes, number of billing codes per patient, and competing financial interest) to responsiveness to financial incentives. Incentive-responsive providers had increased odds (odds ratio [OR], 1.19; 95% CI, 1.04-1.35) of practicing in markets with the highest quartile of provider density but not HHI (OR, 0.96; 95% CI, 0.87-1.05). Incentive-responsive providers were more likely to bill in the highest quartile for unique codes (OR, 1.49; 95% CI, 1.32-1.69) and codes per patient (OR, 1.18; 95% CI, 1.11-1.25) and less likely to have a competing financial interest (OR, 0.76; 95% CI, 0.72-0.81). Responsiveness to financial incentives in cancer care is associated with high market provider density, profit-maximizing billing behavior, and lack of competing financial ownership interests. Identifying physicians and markets responsive to financial incentives may ultimately promote the successful implementation of alternative payment models in cancer care.

Clinical characteristics and treatment response to SSRI in a female pedophile.

Science.gov (United States)

Chow, Eva W C; Choy, Alberto L

2002-04-01

Although much investigation has been done with male sex offenders, there have been few studies on female sex offenders. Female sex offenders have been reported as having a high incidence of psychiatric disorders, but female paraphilics were rarely described. The literature on the treatment of female sex offenders is also limited and treatment with a selective serotonin reuptake inhibitor (SSRI) has not been reported. This paper presents the case of a woman with DSM-IV pedophilia. Her clinical characteristics, her offense history, and her positive response to treatment with sertraline (a SSRI) are described. This case adds to the limited literature on female pedophiles and suggests that SSRIs may be an effective treatment for paraphilic disorders in female sex offenders.

Biophysical Monitoring and dose response characteristics of irradiated hemoglobin

International Nuclear Information System (INIS)

Elshemey, W.M; Selim, N.S.; Desouky, O.

2003-01-01

The present work aims to move a step forward towards a deeper understanding of the scattering of x-ray, from lyophilized biological samples. Comparative study has been performed using LAXS and UV-visible spectrophotometry for monitoring the dose response characteristics of the hemoglobin molecule of irradiated blood. Blood samples were irradiated at doses ranging from 5 up to 100 Gy. Diluted hemoglobin solution was scanned in the UV- visible range (200-700 nm), and lyophilized hemoglobin was prepared for LAXS measurement. The radiation-induced changes in the hemoglobin structure have been evaluated. The LAXS profile of hemoglobin molecule is characterized by the presence of two peaks in the forward direction of scattering. These peaks were found to be sensitive to the variations in the molecular structure of a given sample. The obtained results suggest that the 1 s t peak, recorded at 4.65 o , is sensitive to the tertiary and quaternary structure of the globin part, while the major peak, recorded at 10.5 o , appeared to be related to its primary and secondary structure

Characteristics of highly rated leadership in nursing homes using item response theory.

Science.gov (United States)

Backman, Annica; Sjögren, Karin; Lindkvist, Marie; Lövheim, Hugo; Edvardsson, David

2017-12-01

To identify characteristics of highly rated leadership in nursing homes. An ageing population entails fundamental social, economic and organizational challenges for future aged care. Knowledge is limited of both specific leadership behaviours and organizational and managerial characteristics which have an impact on the leadership of contemporary nursing home care. Cross-sectional. From 290 municipalities, 60 were randomly selected and 35 agreed to participate, providing a sample of 3605 direct-care staff employed in 169 Swedish nursing homes. The staff assessed their managers' (n = 191) leadership behaviours using the Leadership Behaviour Questionnaire. Data were collected from November 2013 - September 2014, and the study was completed in November 2016. A two-parameter item response theory approach and regression analyses were used to identify specific characteristics of highly rated leadership. Five specific behaviours of highly rated nursing home leadership were identified; that the manager: experiments with new ideas; controls work closely; relies on subordinates; coaches and gives direct feedback; and handles conflicts constructively. The regression analyses revealed that managers with social work backgrounds and privately run homes were significantly associated with higher leadership ratings. This study highlights the five most important leadership behaviours that characterize those nursing home managers rated highest in terms of leadership. Managers in privately run nursing homes and managers with social work backgrounds were associated with higher leadership ratings. Further work is needed to explore these behaviours and factors predictive of higher leadership ratings. © 2017 John Wiley & Sons Ltd.

Summary of calculations of dynamic response characteristics and design stress of the 1/5 scale PSE torus

International Nuclear Information System (INIS)

Arthur, D.

1977-01-01

The Lawrence Livermore Laboratory is currently involved in a 1/5 scale testing program on the Mark I BWR pressure suppression system. A key element of the test setup is a pressure vessel that is a 90 0 sector of a torus. Proper performance of the 90 0 torus depends on its structural integrity and structural dynamic characteristics. It must sustain the internal pressurization of the planned tests, and its dynamic response to the transient test loads should be minimal. If the structural vibrations are too great, interpretation of important load cell and pressure transducer data will be difficult. The purpose of the report is to bring together under one cover calculations pertaining to the structural dynamic characteristics and structural integrity of 90 0 torus. The report is divided into the following sections: (1) system description in which the torus and associated hardware are briefly described; (2) structural dynamics in which calculations of natural frequency and dynamic response are presented; and (3) structural integrity in which stress calculations for design purposes are presented; and an appendix which contains an LLL internal report comparing the expected load cell response for a three and four-point supported torus

The design of electrical heater pins to simulate transient dryout and post-dryout of water reactor fuel

International Nuclear Information System (INIS)

Burgess, M.H.; Butcher, A.A.; Sidoli, J.E.A.

1978-11-01

A theoretical assessment of indirect and direct filled heater simulations of nuclear reactor fuel pins is described. For reasons of fast temperature response, a direct unfilled heater, with thermocouples buried in the walls, is recommended for studies of Loss-of-Coolant Accidents leading to dryout, post-dryout and rewetting. A design of heater pins, for use in SGHWR or PWR experiments, and compatible with existing 9MW power supplies, is described. Experiments to confirm collapse pressure calculations at 1000 0 C and thermocouple response times are also reported. (author)

Effect of driving voltage polarity on dynamic response characteristics of electrowetting liquid lens

Science.gov (United States)

Na, Xie; Ning, Zhang; Rong-Qing, Xu

2018-05-01

A test device is developed for studying the dynamic process of an electrowetting liquid lens. By analyzing the light signals through the liquid lens, the dynamical properties of the lens are investigated. In our experiment, three types of pulse, i.e., sine, bipolar pulse, and single pulse signals, are employed to drive the liquid lens, and the dynamic characteristics of the lens are subsequently analyzed. The results show that the positive and negative polarities of the driving voltage can cause a significant difference in the response of the liquid lens; meanwhile, the lens’s response to the negative polarity of the driving voltage is clearer. We use the theory of charge restraint to explain this phenomenon, and it is concluded that the negative ions are more easily restrained by a dielectric layer. This work gives direct guidance for practical applications based on an electrowetting liquid lens.

System for improving measurement accuracy of transducer by measuring transducer temperature and resistance change using thermoelectric voltages

Science.gov (United States)

Anderson, Karl F. (Inventor); Parker, Allen R., Jr. (Inventor)

1993-01-01

A constant current loop measuring system measures a property including the temperature of a sensor responsive to an external condition being measured. The measuring system includes thermocouple conductors connected to the sensor, sensing first and second induced voltages responsive to the external condition. In addition, the measuring system includes a current generator and reverser generating a constant current, and supplying the constant current to the thermocouple conductors in forward and reverse directions generating first and second measured voltages, and a determining unit receiving the first and second measured voltages from the current generator and reverser, and determining the temperature of the sensor responsive to the first and second measured voltages.

Physiological responses and match characteristics in professional tennis players during a one-hour simulated tennis match

Directory of Open Access Journals (Sweden)

Kilit Bülent

2016-06-01

Full Text Available The purpose of this study was to investigate the effects of serve and return game situations on physiological responses and match characteristics in professional male tennis players during one hour-long simulated singles tennis matches. Ten internationally ranked tennis players (age 22.2 ± 2.8 years; body height 180.7 ± 4.4 cm; body mass 75.9 ± 8.9 kg participated in this study. Their physiological responses were measured using two portable analyzers during indoor hard court matches. Ratings of perceived exertion were also determined at the end of the game. The variables describing the characteristics of the matches determined from video recordings were: (a duration of rallies; (b rest time; (c work-to-rest ratio; (d effective playing time; and (d strokes per rally. Significant differences (p<0.05 were found between serving and returning conditions in an hour-long simulated singles tennis match in terms of oxygen uptake, a heart rate, ratings of perceived exertion, pulmonary ventilation, respiration frequency and a respiratory gas exchange ratio. In addition, both the heart rate and ratings of perceived exertion responses were moderately correlated with the duration of rallies and strokes per rally (r = 0.60 to 0.26; p<0.05. Taken together, these results indicate that the serve game situation has a significant effect on the physiological response in an hour-long simulated tennis match between professional male tennis players. These findings might be used for the physiological adaptations required for tennis-specific aerobic endurance.

Leaf gas exchange characteristics of three neotropical mangrove species in response to varying hydroperiod

Science.gov (United States)

Krauss, Ken W.; Twilley, Robert R.; Doyle, Thomas W.; Gardiner, Emile S.

2006-01-01

We determined how different hydroperiods affected leaf gas exchange characteristics of greenhouse-grown seedlings (2002) and saplings (2003) of the mangrove species Avicennia germinans (L.) Stearn., Laguncularia racemosa (L.) Gaertn. f., and Rhizophora mangle L. Hydroperiod treatments included no flooding (unflooded), intermittent flooding (intermittent), and permanent flooding (flooded). Plants in the intermittent treatment were measured under both flooded and drained states and compared separately. In the greenhouse study, plants of all species maintained different leaf areas in the contrasting hydroperiods during both years. Assimilation–light response curves indicated that the different hydroperiods had little effect on leaf gas exchange characteristics in either seedlings or saplings. However, short-term intermittent flooding for between 6 and 22 days caused a 20% reduction in maximum leaf-level carbon assimilation rate, a 51% lower light requirement to attain 50% of maximum assimilation, and a 38% higher demand from dark respiration. Although interspecific differences were evident for nearly all measured parameters in both years, there was little consistency in ranking of the interspecific responses. Species by hydroperiod interactions were significant only for sapling leaf area. In a field study, R. mangle saplings along the Shark River in the Everglades National Park either demonstrated no significant effect or slight enhancement of carbon assimilation and water-use efficiency while flooded. We obtained little evidence that contrasting hydroperiods affect leaf gas exchange characteristics of mangrove seedlings or saplings over long time intervals; however, intermittent flooding may cause short-term depressions in leaf gas exchange. The resilience of mangrove systems to flooding, as demonstrated in the permanently flooded treatments, will likely promote photosynthetic and morphological adjustment to slight hydroperiod shifts in many settings..

EVALUATION ON THE SEISMIC RESPONSE CHARACTERISTICS OF A ROAD EMBANKMENT BASED ON THE MODERATE EARTHQUAKE OBSERVATION AND THE MICROTREMOR MEASUREMENT

Science.gov (United States)

Hata, Yoshiya; Ichii, Koji; Yamada, Masayuki; Tokida, Ken-Ichi; Takezawa, Koichiro; Shibao, Susumu; Mitsushita, Junji; Murata, Akira; Furukawa, Aiko; Koizumi, Keigo

Accurate evaluation on the seismic response characteristics of a road embankment is very important for the rational seismic assessment. However, in a lot of previous studies, the seismic response characteristics of an embankment were evaluated based on the results of shaking table test, centrifuge model test and dynamic FEM analysis. In this study, the transfer function and the shear wave velocity of a road embankment were evaluated based on the in-situ records of moderate earthquake observation and microtremor measurement. Test results show the possibility that the shear wave velocity of an embankment can be estimated by the earthquake observation or the microtremor measurement and the dynamic linear FEM analysis.

Measurement of a neutral particle flux by a thermal method using the junction temperature effect; Mesure d'un flux de particules neutres par une methode thermique mettant a contribution l'effet de temperature des jonctions

Energy Technology Data Exchange (ETDEWEB)

Caron, Anthime [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Services Scientifiques

1966-07-01

Among all the methods suitable for measuring neutral particle fluxes obtained by proton charge exchange in an organic gas, the thermal method has been chosen. The energy imparted by the neutral particles to the target in the form of heat leads to the latter temperature increasing; this temperature is usually followed with a thermocouple. In order to increase the sensitivity and the elegance of the apparatus the thermocouple has been replaced by a junction whose characteristics are known to vary with temperature. A calibration is carried out using a beam of charged particles. The response obtained is linear. Measurements have been made with a power of up to 1 mW; the accuracy increases with the energy provided; for 4 joules an accuracy of 10 per cent is obtained. The apparatus may be improved in particular by extending the measurement range towards low power values, and by increasing the accuracy. (author) [French] Parmi toutes les methodes utilisees pour la mesure d'un flux de particules neutres, obtenues par echange de charge de protons dans un gaz organique, nous avons choisi la methode thermique. L'energie cedee par les particules neutres a la cible sous forme de chaleur provoque une elevation de temperature de celle-ci; cette temperature est habituellement reperee par thermocouple. Pour accroitre la sensibilite et la finesse de l'appareillage, nous avons substitue au thermocouple une jonction dont on sait que les caracteristiques varient avec la temperature. Un etalonnage est realise par un faisceau de particules chargees. La reponse obtenue est lineaire. Des puissances de l'ordre du mW ont ete mesurees; la precision croit avec l'energie apportee; elle est de 10 pour cent quand celle-ci est de 4 joules. L'appareillage peut etre notablement perfectionne, pour reculer la gamme des mesures vers les basses puissances et accroitre la precision. (auteur)

Laser Cladding of Embedded Sensors for Thermal Barrier Coating Applications

Directory of Open Access Journals (Sweden)

Yanli Zhang

2018-05-01

Full Text Available The accurate real-time monitoring of surface or internal temperatures of thermal barrier coatings (TBCs in hostile environments presents significant benefits to the efficient and safe operation of gas turbines. A new method for fabricating high-temperature K-type thermocouple sensors on gas turbine engines using coaxial laser cladding technology has been developed. The deposition of the thermocouple sensors was optimized to provide minimal intrusive features to the TBC, which is beneficial for the operational reliability of the protective coatings. Notably, this avoids a melt pool on the TBC surface. Sensors were deposited onto standard yttria-stabilized zirconia (7–8 wt % YSZ coated substrates; subsequently, they were embedded with second YSZ layers by the Atmospheric Plasma Spray (APS process. Morphology of cladded thermocouples before and after embedding was optimized in terms of topography and internal homogeneity, respectively. The dimensions of the cladded thermocouple were in the order of 200 microns in thickness and width. The thermal and electrical response of the cladded thermocouple was tested before and after embedding in temperatures ranging from ambient to approximately 450 °C in a furnace. Seebeck coefficients of bared and embedded thermocouples were also calculated correspondingly, and the results were compared to that of a commercial standard K-type thermocouple, which demonstrates that laser cladding is a prospective technology for manufacturing microsensors on the surface of or even embedded into functional coatings.

Characteristics of phenomenon and sound in microbubble emission boiling

International Nuclear Information System (INIS)

Zhu Guangyu; Sun Licheng; Tang Jiguo

2014-01-01

Background: Nowadays, the efficient heat transfer technology is required in nuclear energy. Therefore, micro-bubble emission boiling (MEB) is getting more attentions from many researchers due to its extremely high heat-transfer dissipation capability. Purpose: An experimental setup was built up to study the correspondences between the characteristics on the amplitude spectrum of boiling sound in different boiling modes. Methods: The heat element was a copper block heated by four Si-C heaters. The upper of the copper block was a cylinder with the diameter of 10 mm and height of 10 mm. Temperature data were measured by three T-type sheathed thermocouples fitted on the upper of the copper block and recorded by NI acquisition system. The temperature of the heating surface was estimated by extrapolating the temperature distribution. Boiling sound data were acquired by hydrophone and processed by Fourier transform. Bubble behaviors were captured by high-speed video camera with light system. Results: In nucleate boiling region, the boiling was not intensive and as a result, the spectra didn't present any peak. While the MEB fully developed on the heating surface, an obvious peak came into being around the frequency of 300 Hz. This could be explained by analyzing the video data. The periodic expansion and collapse into many extremely small bubbles of the vapor film lead to MEB presenting an obvious characteristic peak in its amplitude spectrum. Conclusion: The boiling mode can be distinguished by its amplitude spectrum. When the MEB fully developed, it presented a characteristic peak in its amplitude spectrum around the frequency between 300-400 Hz. This proved that boiling sound of MEB has a close relation with the behavior of vapor film. (authors)

Thermocouple psychrometer measurements of in situ water potential changes in heated welded tuff

International Nuclear Information System (INIS)

Mao, Nai-hsien; Wang, H.F.

1991-05-01

Ten thermocouple psychrometers (TCPs) to measure water potential (WP) were installed in three holes in G-Tunnel at the Nevada Test Site as part of the Prototype Engineered Barrier System Field Tests. These integrated tests measured several parameters as a function of location and time within a few meters of a heater emplaced in welded tuff. The primary goal of the TCP experiment was to find out whether the combination of laboratory calibration and field use of the TCP can provide useful data for determining the change of moisture condition in the field. We calibrated the TCPs in NaCl solutions up to 80 degree C(176 degree F) in the laboratory. In two holes, we used rubber sleeves and packers to house TCPs, and in the third hole, we used foam. All three holes were grouted behind the TCP assemblages. Field results of the heater test showed that small temperature gradients were present for all measurements. Nevertheless, the WP calibration made the necessary correction for the nonisothermal condition. A drying and re-wetting cycle peaked at about day 140 with a WP of -65 bar in borehole P3, located below the heater. A similar cycle but reduced in scale was found at about day 175 with a WP of -45 bar in borehole P2, above the heater. This difference in drying behavior above and below the heater was also observed from neutron data and was explained as a gravity effect. As temperatures increased, the evaporation rate of pore water increased, In unfractured rock, the gas-phase flow was primarily outward. Water condensed above the heater would drain back to keep the boiling region wet, but water condensed below the heater would drain away from the boiling region. This conceptual model explained both the time and magnitude differences for data from holes above and below the heater. 7 refs., 14 figs., 2 tabs

Reconstruction of core inlet temperature distribution by cold leg temperature measurements

International Nuclear Information System (INIS)

Saarinen, S.; Antila, M.

2010-01-01

The reduced core of Loviisa NPP contains 33 thermocouple measurements measuring the core inlet temperature. Currently, these thermocouple measurements are not used in determining the inlet temperature distribution. The average of cold leg temperature measurements is used as inlet temperature for each fuel assembly. In practice, the inlet temperature distribution is not constant. Thus, using a constant inlet temperature distribution induces asymmetries in the measured core power distribution. Using a more realistic inlet temperature distribution would help us to reduce virtual asymmetries of the core power distribution and increase the thermal margins of the core. The thermocouples at the inlet cannot be used directly to measure the inlet temperature accurately because the calibration of the thermocouples that is done at hot zero power conditions is no longer valid at full power, when there is temperature change across the core region. This is due to the effect of neutron irradiation on the Seebeck coefficient of the thermocouple wires. Therefore, we investigate in this paper a method to determine the inlet temperature distribution based on the cold leg temperature measurements. With this method we rely on the assumption that although the core inlet thermocouple measurements do not measure the absolute temperature accurately they do measure temperature changes with sufficient accuracy particularly in big disturbances. During the yearly testing of steam generator safety valves we observe a large temperature increase up to 12 degrees in the cold leg temperature. The change in the temperature of one of the cold legs causes a local disturbance in the core inlet temperature distribution. Using the temperature changes observed in the inlet thermocouple measurements we are able to fit six core inlet temperature response functions, one for each cold leg. The value of a function at an assembly inlet is determined only by the corresponding cold leg temperature disturbance

Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop

Energy Technology Data Exchange (ETDEWEB)

McCulloch, R.W.; MacPherson, R.E.

1983-03-01

The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

A Canonical Response in Rainfall Characteristics to Global Warming: Projections by IPCC CMIP5 Models

Science.gov (United States)

Lau, William K. M.; Wu, H. T.; Kim, K. M.

2012-01-01

Changes in rainfall characteristics induced by global warming are examined based on probability distribution function (PDF) analysis, from outputs of 14 IPCC (Intergovernmental Panel on Climate Change), CMIP (5th Coupled Model Intercomparison Project) models under various scenarios of increased CO2 emissions. Results show that collectively CMIP5 models project a robust and consistent global and regional rainfall response to CO2 warming. Globally, the models show a 1-3% increase in rainfall per degree rise in temperature, with a canonical response featuring large increase (100-250 %) in frequency of occurrence of very heavy rain, a reduction (5-10%) of moderate rain, and an increase (10-15%) of light rain events. Regionally, even though details vary among models, a majority of the models (>10 out of 14) project a consistent large scale response with more heavy rain events in climatologically wet regions, most pronounced in the Pacific ITCZ and the Asian monsoon. Moderate rain events are found to decrease over extensive regions of the subtropical and extratropical oceans, but increases over the extratropical land regions, and the Southern Oceans. The spatial distribution of light rain resembles that of moderate rain, but mostly with opposite polarity. The majority of the models also show increase in the number of dry events (absence or only trace amount of rain) over subtropical and tropical land regions in both hemispheres. These results suggest that rainfall characteristics are changing and that increased extreme rainfall events and droughts occurrences are connected, as a consequent of a global adjustment of the large scale circulation to global warming.

Long Hole Film Cooling Dataset for CFD Development . Part 1; Infrared Thermography and Thermocouple Surveys

Science.gov (United States)

Shyam, Vikram; Thurman, Douglas; Poinsatte, Phillip; Ameri, Ali; Eichele, Peter; Knight, James

2013-01-01

An experiment investigating flow and heat transfer of long (length to diameter ratio of 18) cylindrical film cooling holes has been completed. In this paper, the thermal field in the flow and on the surface of the film cooled flat plate is presented for nominal freestream turbulence intensities of 1.5 and 8 percent. The holes are inclined at 30deg above the downstream direction, injecting chilled air of density ratio 1.0 onto the surface of a flat plate. The diameter of the hole is 0.75 in. (0.01905 m) with center to center spacing (pitch) of 3 hole diameters. Coolant was injected into the mainstream flow at nominal blowing ratios of 0.5, 1.0, 1.5, and 2.0. The Reynolds number of the freestream was approximately 11,000 based on hole diameter. Thermocouple surveys were used to characterize the thermal field. Infrared thermography was used to determine the adiabatic film effectiveness on the plate. Hotwire anemometry was used to provide flowfield physics and turbulence measurements. The results are compared to existing data in the literature. The aim of this work is to produce a benchmark dataset for Computational Fluid Dynamics (CFD) development to eliminate the effects of hole length to diameter ratio and to improve resolution in the near-hole region. In this report, a Time-Filtered Navier Stokes (TFNS), also known as Partially Resolved Navier Stokes (PRNS), method that was implemented in the Glenn-HT code is used to model coolant-mainstream interaction. This method is a high fidelity unsteady method that aims to represent large scale flow features and mixing more accurately.

Certain Type Turbofan Engine Whole Vibration Model with Support Looseness Fault and Casing Response Characteristics

Directory of Open Access Journals (Sweden)

H. F. Wang

2014-01-01

Full Text Available Support looseness fault is a type of common fault in aeroengine. Serious looseness fault would emerge under larger unbalanced force, which would cause excessive vibration and even lead to rubbing fault, so it is important to analyze and recognize looseness fault effectively. In this paper, based on certain type turbofan engine structural features, a rotor-support-casing whole model for certain type turbofan aeroengine is established. The rotor and casing systems are modeled by means of the finite element beam method; the support systems are modeled by lumped-mass model; the support looseness fault model is also introduced. The coupled system response is obtained by numerical integral method. In this paper, based on the casing acceleration signals, the impact characteristics of symmetrical stiffness and asymmetric stiffness models are analyzed, finding that the looseness fault would lead to the longitudinal asymmetrical characteristics of acceleration time domain wave and the multiple frequency characteristics, which is consistent with the real trial running vibration signals. Asymmetric stiffness looseness model is verified to be fit for aeroengine looseness fault model.

Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

Energy Technology Data Exchange (ETDEWEB)

Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

1984-05-01

This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage.

Engineering characterization of ground motion. Task I. Effects of characteristics of free-field motion on structural response

International Nuclear Information System (INIS)

Kennedy, R.P.; Short, S.A.; Merz, K.L.; Tokarz, F.J.; Idriss, I.M.; Power, M.S.; Sadigh, K.

1984-05-01

This report presents the results of the first task of a two-task study on the engineering characterization of earthquake ground motion for nuclear power plant design. The overall objective of this study is to develop recommendations for methods for selecting design response spectra or acceleration time histories to be used to characterize motion at the foundation level of nuclear power plants. Task I of the study develops a basis for selecting design response spectra, taking into account the characteristics of free-field ground motion found to be significant in causing structural damage

Study of thermal - hydraulic sensors signal fluctuations in PWR

International Nuclear Information System (INIS)

Hennion, F.

1987-10-01

This thesis deals with signal fluctuations of thermal-hydraulic sensors in the main coolant primary of a pressurized water reactor. The aim of this work is to give a first response about the potentiality of use of these noise signals for the functionning monitoring. Two aspects have been studied: - the modelisation of temperature fluctuations of core thermocouples, by a Monte-Carlo method, gives the main characteristics of these signals and their domain of application. - the determination of eigenfrequency in the primary by an acoustic representation could permit the monitoring of local and global thermo-hydraulic conditions [fr

Dose response characteristics of polymethacrylic acid gel (PMAAG) for a polymerization-based dosimeter using NMR.

Science.gov (United States)

Iskandar, S M; Elias, S; Jumiah, H; Asri, M T M; Masrianis, A; Ab Rahman, M Z; Taiman, K; Abdul Rashid, M Y

2004-05-01

The radiation-response characteristics of polymetharylic acid gel dosimeter prepared with different concentrations of monomer and cross-linker is described in these studies. The dosimeters were prepared under the hypoxic condition in a glove box and were then irradiated with gamma-rays produced by Co-60 radionuclide that was generated at 1.25MeV energy. The irradiation took place at different doses ranged from 0Gy to 19Gy. Due to the radiation activities, chain-reaction polymerisation processes had taken place in the formation of polymethacrylic acid (PMAA) gel, which cause the dose response mechanism increased in the NMR relaxation rates of protons. It has been observed that for higher concentration of monomer and cross-linker, the polymerization rate was increased.

X-ray conditions and response characteristics of automatic dose control in cinematography

International Nuclear Information System (INIS)

Arai, Hiroaki

1997-01-01

X-ray characteristics including subject thickness (copper plate), tube voltage, tube current and irradiation time were measured at stability, with an automatic dose control x-ray generator for cineangiography. Regardless of subject thickness, it is possible that the energy input to the x-ray tube in one frame may be decreased. The automatic control response was measured after rapid fluctuation in subject thickness. Two inverter-type x-ray generators with different automatic control units were studied. The older control unit changes exposure dose by tube voltage and tube current, while the newer one changes exposure dose by tube voltage, tube current and irradiation time. The maximum rate of change in tube voltage is greater with the newer control unit. In addition, the actual tube current response of the newer control unit in increasing nominal value is faster than the older one. In the new control unit, for each pulse, irradiation is cut off by means of a signal that the exposure has reached the proper value. Thus given the same differential in subject thickness, the newer control unit resumed stability faster than the older one. (author)

X-ray conditions and response characteristics of automatic dose control in cinematography

Energy Technology Data Exchange (ETDEWEB)

Arai, Hiroaki [Cardiovascular Institute Hospital, Tokyo (Japan)

1997-11-01

X-ray characteristics including subject thickness (copper plate), tube voltage, tube current and irradiation time were measured at stability, with an automatic dose control x-ray generator for cineangiography. Regardless of subject thickness, it is possible that the energy input to the x-ray tube in one frame may be decreased. The automatic control response was measured after rapid fluctuation in subject thickness. Two inverter-type x-ray generators with different automatic control units were studied. The older control unit changes exposure dose by tube voltage and tube current, while the newer one changes exposure dose by tube voltage, tube current and irradiation time. The maximum rate of change in tube voltage is greater with the newer control unit. In addition, the actual tube current response of the newer control unit in increasing nominal value is faster than the older one. In the new control unit, for each pulse, irradiation is cut off by means of a signal that the exposure has reached the proper value. Thus given the same differential in subject thickness, the newer control unit resumed stability faster than the older one. (author)

Study on DFIG wind turbines control strategy for improving frequency response characteristics

Science.gov (United States)

Zhao, Dongmei; Wu, Di; Liu, Yanhua; Zhou, Zhiyu

2012-01-01

The active and reactive power decoupling control for the double-fed induction generator wind turbines(DFIG) does not play a positive role to the frequency response ability of power grid because it performs as the hidden inertia for the power grid. If we want to improve the transient frequency stability of the wind turbine when it is integrated with the system, we must ameliorate its frequency response characteristics. The inability of frequency control due to DFIG decoupling control could be overcome through releasing (or absorbing) a part of the kinetic energy stored in the rotor, so as to increase (or decrease) active power injected to the power system when the deviation of power system frequency appears. This paper discusses the mathematical model of the variable speed DFIG, including the aerodynamic model, pitch control system model, shaft model, generator model and inverter control model, and other key components, focusing on the mathematical model of the converters in rotor side and grid side. Based on the existing model of wind generator, the paper attaches the frequency control model on the platform of the simulation software DIgSILENT/PowerFactory. The simulation results show that the proposed control strategy can response quickly to transient frequency deviation and prove that wind farms can participate in the system frequency regulation to a certain extent. Finally, the result verifies the accuracy and plausibility of the inverter control model which attaches the frequency control module.

Comparison of the frequency response characteristics of catheter-mounted piezoelectric and micromanometric phonotransducers.

Science.gov (United States)

Garcia, J C; Layton, S A; Rubal, B J

1989-05-01

This study compares the frequency response characteristics of catheter-mounted piezoelectric sound transducers with micromanometric transducers. The tip of a 8F catheter with two piezoelectric transducers and two micromanometers was inserted into a water-filled chamber that had a speaker fixed at one end. The speaker was driven by a power amplifier and sine wave generator. The outputs of the transducers were connected to a low-level amplifier. The piezoelectric transducer behaved as a tunable high-pass filter that could be modified by altering the input impedance of the low level amplifier; the frequency response characteristics were examined at five input impedances ranging from 0.96 to 11.8 megohms. The peak-to-peak outputs of the piezoelectric and pressure transducers were recorded at frequency ranges from DC to 1 kHz with a wide-band oscilloscope. The ratio of the outputs from the piezotransducer and micromanometer (Vph/Vpr) was plotted vs. frequency for each input impedance and analyzed to determine the piezotransducer's output resistance and equivalent capacitance; roll-off frequencies were then calculated. The equivalent capacitance of the piezo-element was determined to be 500-700 picofarads. Series capacitance acted with network resistance to produce a predictable frequency-dependent change in signal amplitude and phase angle. The inherent noise of the pressure transducer was found to be approximately 0.2 mm Hg, while the noise of the piezoelectric transducer was immeasurably low. The piezoelectric phonotransducers were superior to micromanometer transducers in their higher gain and lower noise, suggesting that these transducers may prove useful to physiologic and clinical studies for measuring intravascular sound.

Assessment of flood Response Characteristics to Urbanization and extreme flood events-Typhoons at Cheongju, Chungbuk

Science.gov (United States)

Chang, HyungJoon; Lee, Hyosang; Hwang, Myunggyu; Jang, Sukhwan

2016-04-01

The changes of land use influence on the flood characteristics, which depend on rainfall runoff procedures in the catchment. This study assesses the changes of flood characteristics due to land use changes between 1997 and 2012. The catchment model (HEC-HMS) is calibrated with flood events of 1990's and 2000's respectively, then the design rainfall of 100, 200, 500year return period are applied to this model, which represent the catchment in 1990's and 2000's, to assess the flood peaks. Then the extreme flood events (i.e., 6 typhoon events) are applied to assess the flood responses. The results of comparison between 1990's and 2000's show that the flood peak and level of 2000's are increasing and time to peak of 2000's is decreasing comparing to those of 1990's :3% to 78% increase in flood peak, 3% in flood level and 10.2% to 16% decrease in time to peak in 100year return period flood. It is due to decreasing of the farmland area (2.18%), mountainous area (8.88%), and increasing of the urbanization of the area (5.86%). This study also estimates the responses to extreme flood events. The results of 2000's show that the increasing of the flood peak and time to peak comparing to 1990's. It indicates that the extreme rainfall is more responsible at unurbanized catchment ( 2000's), which resulting with a 11% increasing of the peak volume. Acknowledgement This research was supported by a grant (11-TI-C06) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Aerodynamic characteristics and thermal structure of nonpremixed reacting swirling wakes at low Reynolds numbers

Energy Technology Data Exchange (ETDEWEB)

Huang, Rong F. [Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei (China); Yen, Shun C. [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, Keelung (China)

2008-12-15

The aerodynamic characteristics and thermal structure of uncontrolled and controlled swirling double-concentric jet flames at low Reynolds numbers are experimentally studied. The swirl and Reynolds numbers are lower than 0.6 and 2000, respectively. The flow characteristics are diagnosed by the laser-light-sheet-assisted Mie scattering flow visualization method and particle image velocimetry (PIV). The thermal structure is measured by a fine-wire thermocouple. The flame shapes, combined images of flame and flow, velocity vector maps, streamline patterns, velocity and turbulence distributions, flame lengths, and temperature distributions are discussed. The flow patterns of the no-control case exhibit an open-top, single-ring vortex sitting on the blockage disc with a jetlike swirling flow evolving from the central disc face toward the downstream area. The rotation direction and size of the near-disc vortex, as well as the flow properties, change in different ranges of annulus swirl number and therefore induce three characteristic flame modes: weak swirling flame, lifted flame, and turbulent reattached flame. Because the near-disc vortex is open-top, the radial dispersion of the fuel-jet fluids is not significantly enhanced by the annulus swirling flow. The flows of the reacting swirling double-concentric jets at such low swirl and Reynolds numbers therefore present characteristics of diffusion jet flames. In the controlled case, the axial momentum of the central fuel jet is deflected radially by a control disc placed above the blockage disc. This arrangement can induce a large near-disc recirculation bubble and high turbulence intensities. The enhanced mixing hence tremendously shortens the flame length and enlarges the flame width. (author)

Surfactant effect on functionalized carbon nanotube coated snowman-like particles and their electro-responsive characteristics

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ke; Liu, Ying Dan [Department of Polymer Science and Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Choi, Hyoung Jin, E-mail: hjchoi@inha.ac.kr [Department of Polymer Science and Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

2012-10-15

The core–shell structured snowman-like (SL) microparticles coated by functionalized multi-walled carbon nanotube (MWNT) were prepared in the presence of different surfactants including cationic surfactant-cetyl trimethylammonium bromide (CTAB) and anionic surfactant-sodium lauryl sulfate (SDS). The effect of surfactants on adsorption onto SL particles was characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and conductivity. The cationic surfactant is found to be more effective than anionic surfactant for helping nanotube adsorbed onto microparticle due to the presence of electrostatic interaction between the functionalized MWNT and the surfactant. Furthermore, the MWNT/SL particles dispersed in silicone oil exhibited a typical fibril structure of the electrorheological characteristics under an applied electric field observed by an optical microscope (OM), in which the state of nanotubes wrapped on the particles strongly affects their electro-responsive characteristics.

Surfactant effect on functionalized carbon nanotube coated snowman-like particles and their electro-responsive characteristics

International Nuclear Information System (INIS)

Zhang, Ke; Liu, Ying Dan; Choi, Hyoung Jin

2012-01-01

The core–shell structured snowman-like (SL) microparticles coated by functionalized multi-walled carbon nanotube (MWNT) were prepared in the presence of different surfactants including cationic surfactant-cetyl trimethylammonium bromide (CTAB) and anionic surfactant-sodium lauryl sulfate (SDS). The effect of surfactants on adsorption onto SL particles was characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and conductivity. The cationic surfactant is found to be more effective than anionic surfactant for helping nanotube adsorbed onto microparticle due to the presence of electrostatic interaction between the functionalized MWNT and the surfactant. Furthermore, the MWNT/SL particles dispersed in silicone oil exhibited a typical fibril structure of the electrorheological characteristics under an applied electric field observed by an optical microscope (OM), in which the state of nanotubes wrapped on the particles strongly affects their electro-responsive characteristics.

ROCView: prototype software for data collection in jackknife alternative free-response receiver operating characteristic analysis

Science.gov (United States)

Thompson, J; Hogg, P; Thompson, S; Manning, D; Szczepura, K

2012-01-01

ROCView has been developed as an image display and response capture (IDRC) solution to image display and consistent recording of reader responses in relation to the free-response receiver operating characteristic paradigm. A web-based solution to IDRC for observer response studies allows observations to be completed from any location, assuming that display performance and viewing conditions are consistent with the study being completed. The simplistic functionality of the software allows observations to be completed without supervision. ROCView can display images from multiple modalities, in a randomised order if required. Following registration, observers are prompted to begin their image evaluation. All data are recorded via mouse clicks, one to localise (mark) and one to score confidence (rate) using either an ordinal or continuous rating scale. Up to nine “mark-rating” pairs can be made per image. Unmarked images are given a default score of zero. Upon completion of the study, both true-positive and false-positive reports can be downloaded and adapted for analysis. ROCView has the potential to be a useful tool in the assessment of modality performance difference for a range of imaging methods. PMID:22573294

DGMK 729. Application characteristics of fuels with biogenic components

Energy Technology Data Exchange (ETDEWEB)

Neulen, Martin; Hoffmann, Hajo [OWI - Oel-Waerme-Institut GmbH, Herzogenrath (Germany)

2013-06-01

Using the test rig developed within a project funded by the DGMK (project 729), fuel can be aged semi-realistically in a short time. The test rig was designed to age a fuel within less than 1,000 hours of operation. Another aspect was to investigate the influence of the different aging mechanisms on the fuel, such as light, ambient air, high temperatures and mechanical stress. By defining these parameters and intensifying them, the goal of 1,000 hours of operation has already been achieved in the first test run. A high repeatability and the possibility to vary the parameters of the test runs for all four nearly identical apparatuses are the main characteristics of this test rig. With this test rig it can be tried out how additives react when the fuel ages and how a fuel behaves during its storage. The test runs are supervised by pressure transducer and thermocouples, so that the test rig can be operated unattendedly when started. During the test run every 300 hours of operation fuel samples are taken. These samples are analyzed according to an analysis matrix. Furthermore, the deposits sedimented in the filters or other components can be analyzed. By this, the aging can be understood and monitored. (orig.)

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

Energy Technology Data Exchange (ETDEWEB)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

2016-10-15

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

International Nuclear Information System (INIS)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

2016-01-01

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

Assessing the Value of Regulation Resources Based on Their Time Response Characteristics

Energy Technology Data Exchange (ETDEWEB)

Makarov, Yuri V.; Lu, Shuai; Ma, Jian; Nguyen, Tony B.

2008-06-01

Fast responsive regulation resources are potentially more valuable as a power system regulation resource (more efficient) because they allow applying controls at the exact moment and in the exact amount as needed. Faster control is desirable because it facilitates more reliable compliance with the NERC Control Performance Standards at relatively lesser regulation capacity procurements. The current California ISO practices and markets do not provide a differentiation among the regulation resources based on their speed of response (with the exception of some minimum ramping capabilities). Some demand response technologies, including some generation and energy storage resources, can provide quicker control actions. California ISO practices and markets could be updated to welcome more fast regulation resources into the California ISO service area. The project work reported in this work was pursuing the following objectives: • Develop methodology to assess the relative value of generation resources used for regulation and load following California ISO functions • This assessment should be done based on physical characteristics including the ability to quickly change their output following California ISO signals • Evaluate what power is worth on different time scales • Analyze the benefits of new regulation resources to provide effective compliance with the mandatory NERC Control Performance Standards • Evaluate impacts of the newly proposed BAAL and FRR standards on the potential value of fast regulation and distributed regulation resources • Develop a scope for the follow-up projects to pave a road for the new efficient types of balancing resources in California. The work included the following studies: • Analysis of California ISO regulating units characteristics • California ISO automatic generation system (AGC) analysis • California ISO regulation procurement and market analysis • Fast regulation efficiency analysis • Projection of the

Differential Responses to Food Price Changes by Personal Characteristic: A Systematic Review of Experimental Studies.

Science.gov (United States)

Mizdrak, Anja; Scarborough, Peter; Waterlander, Wilma E; Rayner, Mike

2015-01-01

Fiscal interventions to improve population diet have been recommended for consideration by many organisations including the World Health Organisation and the United Nations and policies such as sugar-sweetened beverage taxes have been implemented at national and sub-national levels. However, concerns have been raised with respect to the differential impact of fiscal interventions on population sub-groups and this remains a barrier to implementation. To examine how personal characteristics (such as socioeconomic status, sex, impulsivity, and income) moderate changes in purchases of targeted foods in response to food and beverage price changes in experimental settings. Systematic review. Online databases (PubMed, EMBASE, Web of Science, EconLit and PsycInfo), reference lists of previous reviews, and additional data from study authors. We included randomised controlled trials where food and beverage prices were manipulated and reported differential effects of the intervention on participant sub-groups defined according to personal characteristics. Where possible, we extracted data to enable the calculation of price elasticities for the target foods by personal characteristic. 8 studies were included in the review. Across studies, the difference in price elasticity varied from 0.02 to 2.43 between groups within the same study. 11 out of the total of 18 comparisons of own-price elasticity estimates by personal characteristic differed by more than 0.2 between groups. Income related factors were the most commonly considered and there was an indication that own-price elasticity estimates do vary by income but the direction of this effect was not clear. Experimental studies provide an opportunity to examine the differential effects of fiscal measures to improve population diets. Patterns in price sensitivity by personal characteristics are complex. General conclusions pertaining to the effects of personal characteristics on price sensitivity are not supported by the

A new method to evaluate patient characteristic response to ultrafiltration during hemodialysis.

Science.gov (United States)

Casagrande, G; Teatini, U; Romei Longhena, G; Miglietta, F; Fumero, R; Costantino, M L

2007-05-01

Several factors are involved in the pathogenesis of dialysis discomfort interfering with optimal fluid removal and reducing the efficacy of the treatment; the most important one is a decrease in blood volume caused by an imbalance between ultrafiltration (UF) and plasmarefilling (PR) rates. This study is aimed at devising a method to tailor the dialysis therapy to each individual patient, by analyzing the relationship between PR and UF during the sessions in stable patients and widening the knowledge of fluid exchanges during the treatment. Thirty stable patients undergoing maintenance hemodialysis were enrolled. Three dialysis sessions were monitored for each patient; systemic pressure, blood composition, blood volume % variation, weight loss and conductivity were recorded repeatedly. A Plasma Refilling Index (PRI), defined and calculated by means of parameters measured throughout the dialysis, was introduced as a novel instrument to study plasma refilling phenomena. Results. The PRI provides understanding of patient response (in terms of plasma refilling) to the set UF. In the monitored sessions, the PRI trend is found to be characteristic of each patient; a PRI course that is at variance with the characteristic trend is a signal of inadequate or unusual dialysis scheduling. Moreover, statistical analysis highlights two different PRI trends during the first hour and during the rest of the treatment, suggesting the presence of different treatment phases. The main advantage of the PRI index is that it is non-invasive peculiar to each patient and easy to compute in a dialysis routine based on online data recorded by the monitor. A deviation from the characteristic trend may be a warning for the clinician. The analysis of the PRI trend also suggests how to modulate UF as a function of interstitial to intravascular fluid removal balance during dialysis.

KARAKTERISTIK PERTANGGUNGJAWABAN PIDANA KORPORASI (The Characteristics of Corporate Criminal Responsibility

Directory of Open Access Journals (Sweden)

Adriano Adriano

2016-03-01

Full Text Available Disertasi ini membahas lebih dalam mengenai karakteristik korporasi yang berbadan hukum maupun yang tidak berbadan hukum, keduanya didiskusikan pada kerangka yang sama dari pertanggungjawaban pidana korporasi. Meskipun demikian, seringkali pada beberapa hukum atau peraturan selain KUHP, baik pada hukum pidana maupun hukum administratif dengan sanksi pidana, perusahaan digambarkan sebagai sekumpulan orang/kekayaan yang terorganisir baik yang berbadan hukum maupun yang tidak. Pengertian ini sangat jauh berbeda dari apa yang dinyatakan oleh para ahli hukum terutama pada hukum pidana yang biasanya menyatakan perusahaan sebagai badan hukum. Meskipun demikian, hal ini tidaklah sama bagi perusahaan yang tidak berbadan hukum. Perbedaan tersebut akan menyebabkan konsekuensi hukum tersendiri karena perusahaan tidak bisa dan tidak akan pernah diperlakukan sama terkait pertanggungjawaban pidana korporasi.   This dissertation analyzed for real about characteristics of an entity, either a legal or the nonlegal "entity'' which all were discussed in the same outline of corporate crime responsibility. It was often, though, in several laws aside from the Penal Code of Indonesia (KUHP, both in Criminal Law and Administrative Law with criminal sanction, that corporate is defined as a collection of organized people and or wealth, either as a legal or the nonlegal entity. The definitions in those laws are really different from those of law experts, especially those of criminal law who basically identify corporate as a legal entity, however the same is not true for those of the nonlegal entity. Such differences of the legal and nonlegal entities would bring their own legal consequences, therefore they could not and would not be treated the same referring to corporate criminal responsibility.

Influence of surface defects in ZnO thin films on its biosensing response characteristic

Energy Technology Data Exchange (ETDEWEB)

Saha, Shibu; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India)

2011-09-15

Highly c-axis oriented zinc oxide (ZnO) thin films deposited by rf magnetron sputtering under varying processing pressure (20-50 mT) in a reactive gas mixture of argon and oxygen were studied for biosensing application. The as-deposited ZnO thin films were in a state of compressive stress having defects related to interstitial Zn and antisite oxygen. Glucose oxidase has been chosen as the model enzyme in the present study and was immobilized on the surface of ZnO thin films deposited on indium tin oxide coated Corning Glass substrate. The studies reveal a correlation between the biosensing characteristic and the presence of defects in the ZnO films. The ZnO films deposited under high pressure (50 mT) are found to be more sensitive for biosensing application due to availability of more surface area for effective immobilization of biomolecules and exhibits a suitable microenvironment with good electron transfer characteristic. The obtained results highlight the importance of desired microstate besides availability of suitable native defects in the ZnO thin film for exhibiting enhanced biosensing response.

Influence of surface defects in ZnO thin films on its biosensing response characteristic

International Nuclear Information System (INIS)

Saha, Shibu; Gupta, Vinay

2011-01-01

Highly c-axis oriented zinc oxide (ZnO) thin films deposited by rf magnetron sputtering under varying processing pressure (20-50 mT) in a reactive gas mixture of argon and oxygen were studied for biosensing application. The as-deposited ZnO thin films were in a state of compressive stress having defects related to interstitial Zn and antisite oxygen. Glucose oxidase has been chosen as the model enzyme in the present study and was immobilized on the surface of ZnO thin films deposited on indium tin oxide coated Corning Glass substrate. The studies reveal a correlation between the biosensing characteristic and the presence of defects in the ZnO films. The ZnO films deposited under high pressure (50 mT) are found to be more sensitive for biosensing application due to availability of more surface area for effective immobilization of biomolecules and exhibits a suitable microenvironment with good electron transfer characteristic. The obtained results highlight the importance of desired microstate besides availability of suitable native defects in the ZnO thin film for exhibiting enhanced biosensing response.

Experimental study on the response characteristics of coal permeability to pore pressure under loading and unloading conditions

Science.gov (United States)

Ye, Zhiwei; Zhang, Lei; Hao, Dingyi; Zhang, Cun; Wang, Chen

2017-10-01

In order to study the response characteristics of coal permeability to pore pressure, seepage experiments under different simulated in situ stresses on loading and unloading paths are carried out using the self-developed Gas Flow and Displacement Testing Apparatus (GFDTA) system. Based on the analysis of the experimental data, the relationship between average pore pressure and permeability is found to basically obey the function distribution of a two degree polynomial. In this paper, two aspects of the relationship between permeability and pore pressure are explained: the Klinbenberg effect and expansion, and the penetration of the initial fracture. Under low pore pressure, the decrease in the Klinbenberg effect is the main reason for the decrease in permeability with increased pore pressure. Under relatively high pore pressure, the increase in pore pressure leads to the initial fracture expansion and penetration of the coal sample, which causes an increase in permeability. In order to evaluate the sensitivity of the permeability response to pore pressure changes, the permeability dispersion and pore pressure sensitivity coefficients are defined. After the sensitivity analysis, it was concluded that the loading history changed the fracture structure of the original coal sample and reduced its permeability sensitivity to pore pressure. Under low pore pressure, the Klinbenberg effect is the reason for the decrease in pore pressure sensitivity. Lastly, the permeability-pore pressure relationship is divided into three stages to describe the different response characteristics individually.

Glow curve characteristics of bulb type thermoluminescent dosimeters

International Nuclear Information System (INIS)

Deme, S.; Feher, I.; Felszerfalvi, J.

1993-01-01

TL dosemeter readers are equipped usually with thermocouples connected to the heater unit. This layout can well be applied to stabilize the position of the glow curve as a function of heating-up time. Bulb type TL dosemeters do not have temperature sensors, no possibility for stabilization, which can cause an additional readout error of dose determination. For this reason, the time dependence of glow curves for bulb-type TL dosemeters was measured, and a new microprocessor controlled readout device was developed. (N.T.) 2 refs.; 2 figs

Influence of activated carbon characteristics on toluene and hexane adsorption: Application of surface response methodology

Science.gov (United States)

Izquierdo, Mª Teresa; de Yuso, Alicia Martínez; Valenciano, Raquel; Rubio, Begoña; Pino, Mª Rosa

2013-01-01

The objective of this study was to evaluate the adsorption capacity of toluene and hexane over activated carbons prepared according an experimental design, considering as variables the activation temperature, the impregnation ratio and the activation time. The response surface methodology was applied to optimize the adsorption capacity of the carbons regarding the preparation conditions that determine the physicochemical characteristics of the activated carbons. The methodology of preparation produced activated carbons with surface areas and micropore volumes as high as 1128 m2/g and 0.52 cm3/g, respectively. Moreover, the activated carbons exhibit mesoporosity, ranging from 64.6% to 89.1% the percentage of microporosity. The surface chemistry was characterized by TPD, FTIR and acid-base titration obtaining different values of surface groups from the different techniques because the limitation of each technique, but obtaining similar trends for the activated carbons studied. The exhaustive characterization of the activated carbons allows to state that the measured surface area does not explain the adsorption capacity for either toluene or n-hexane. On the other hand, the surface chemistry does not explain the adsorption results either. A compromise between physical and chemical characteristics can be obtained from the appropriate activation conditions, and the response surface methodology gives the optimal activated carbon to maximize adsorption capacity. Low activation temperature, intermediate impregnation ratio lead to high toluene and n-hexane adsorption capacities depending on the activation time, which a determining factor to maximize toluene adsorption.

Response characteristics of a new bidirectional vane

International Nuclear Information System (INIS)

SethuRaman, S.; Tuthill, W.A.

1978-01-01

The design and construction of a bivane to measure horizontal and elevation angle fluctuations in the atmosphere are presented. Wind tunnel tests indicated a reasonably high-frequency response. Field comparisons with a commercially available instrument gave good results. A unique feature in the design of this bivane is its ruggedness in combination with good frequency response

Response rates in case-control studies of cancer by era of fieldwork and by characteristics of study design.

Science.gov (United States)

Xu, Mengting; Richardson, Lesley; Campbell, Sally; Pintos, Javier; Siemiatycki, Jack

2018-04-09

The purpose of this study was to describe time trends in response rates in case-control studies of cancer and identify study design factors that influence response rate. We reviewed 370 case-control studies of cancer published in 12 journals during indicator years in each of the last four decades. We estimated time trends of response rates and reasons for nonresponse in each of the following types of study subjects: cases, medical source controls, and population controls. We also estimated response rates according to characteristics of study context. Median response rates among cases and population controls were between 75% and 80% in the 1970s. Between 1971 and 2010, study response rates declined by 0.31% per year for cases and 0.78% for population controls. Only a minority of studies reported reasons for nonparticipation; subject refusal was the most common reported reason. Studies conducted in North America had lower median response rates than studies conducted in Europe. In-person and telephone interviews elicited higher response rates than mail questionnaires. Response rates from case-control studies of cancer have declined, and this could threaten the validity of results derived from these studies. Copyright © 2018 Elsevier Inc. All rights reserved.

Polysensory response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia.

Science.gov (United States)

Huang, M H; Horackova, M; Negoescu, R M; Wolf, S; Armour, J A

1996-09-01

To determine the response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia. Extracellular recordings were made from 54 spontaneously active and 5 normally quiescent dorsal root ganglion neurones (T2-T5) in 22 anaesthetized open-chest dogs under control conditions and during epicardial mechanical or chemical stimulation and myocardial ischaemia. The activity of 78% of spontaneously active and all quiescent neurones with left ventricular sensory fields was modified by left ventricular ischaemia. Forty-six spontaneously active neurones (85%) were polysensory with respect to mechanical and chemical stimuli. The 5 quiescent neurones responded only to chemical stimuli. Spontaneously active neurones associated with left ventricular mechanosensory endings (37 neurones) generated four different activity patterns in response to similar mechanical stimuli (high or low pressure active, high-low pressure active, high-low pressure inactive). A fifth group generated activity which was not related to chamber dynamics. Adenosine, adenosine 5'-triphosphate, substance P and bradykinin modified 72, 61, 65 and 63% of the spontaneously active neurones, respectively. Maximum local mechanical or chemical stimuli enhanced activity to similar degrees, as did ischaemia. Each ischaemia-sensitive neurone displayed unique activity patterns in response to similar mechanical or chemical stimuli. Most myocardial ischemia-sensitive dorsal root ganglion neurones associated with epicardial neurites sense mechanical and multiple chemical stimuli, a small population sensing only mechanical or chemical stimuli. Activity patterns generated by these neurones depend on their primary sensory characteristics or those of other neurones that may converge on them, as well as the type and magnitude of the stimuli that impinge upon their sensory fields, both normally and during ischaemia.

Analysis of output characteristics of PV modules under natural sunlight; Shizen taiyokoka ni okeru taiyo denchi module shutsuryoku tokusei no kaiseki

Energy Technology Data Exchange (ETDEWEB)

Murai, Y.; Igari, S. [Japan Quality Assurance of Organization, Tokyo (Japan)

1997-11-25

The paper measured current/voltage characteristics of various PV modules under natural light and analyzed various characteristics such as generated output and module power generation efficiency. In the experiment, installing various PV modules at the solar techno center located at north latitude 34.7deg and east longitude 137.6deg, measurement was made by I-V curve tracer, pyranometer, and thermocouple buried on the module back. As a result, the following were confirmed: As to the monthly mean power generation efficiency, the crystalline system is lowest in summer and highest in winter, and the amorphous system highest in summer and lowest in winter. Concerning the power generation efficiency and illuminance, the gap of power generation efficiency between at high illuminance and at low illuminance is large in the crystalline system and small in amorphous system. Relating to the azimuth angle of module installation and the generated output, the installation inclined 15deg angle west in summer and 15deg angle east in fall/winter generates more power in the crystalline system. On the contrary, the installation on the south face generates more power in the amorphous system. 4 refs., 8 figs., 3 tabs.

Maximum likelihood estimation of dose-response parameters for therapeutic operating characteristic (TOC) analysis of carcinoma of the nasopharynx

International Nuclear Information System (INIS)

Metz, C.E.; Tokars, R.P.; Kronman, H.B.; Griem, M.L.

1982-01-01

A Therapeutic Operating Characteristic (TOC) curve for radiation therapy plots, for all possible treatment doses, the probability of tumor ablation as a function of the probability of radiation-induced complication. Application of this analysis to actual therapeutic situation requires that dose-response curves for ablation and for complication be estimated from clinical data. We describe an approach in which ''maximum likelihood estimates'' of these dose-response curves are made, and we apply this approach to data collected on responses to radiotherapy for carcinoma of the nasopharynx. TOC curves constructed from the estimated dose-response curves are subject to moderately large uncertainties because of the limitations of available data.These TOC curves suggest, however, that treatment doses greater than 1800 rem may substantially increase the probability of tumor ablation with little increase in the risk of radiation-induced cervical myelopathy, especially for T1 and T2 tumors

Sensing Responses Based on Transfer Characteristics of InAs Nanowire Field-Effect Transistors

Science.gov (United States)

Savelyev, Igor; Blumin, Marina; Wang, Shiliang; Ruda, Harry E.

2017-01-01

Nanowire-based field-effect transistors (FETs) have demonstrated considerable promise for a new generation of chemical and biological sensors. Indium arsenide (InAs), by virtue of its high electron mobility and intrinsic surface accumulation layer of electrons, holds properties beneficial for creating high performance sensors that can be used in applications such as point-of-care testing for patients diagnosed with chronic diseases. Here, we propose devices based on a parallel configuration of InAs nanowires and investigate sensor responses from measurements of conductance over time and FET characteristics. The devices were tested in controlled concentrations of vapour containing acetic acid, 2-butanone and methanol. After adsorption of analyte molecules, trends in the transient current and transfer curves are correlated with the nature of the surface interaction. Specifically, we observed proportionality between acetic acid concentration and relative conductance change, off current and surface charge density extracted from subthreshold behaviour. We suggest the origin of the sensing response to acetic acid as a two-part, reversible acid-base and redox reaction between acetic acid, InAs and its native oxide that forms slow, donor-like states at the nanowire surface. We further describe a simple model that is able to distinguish the occurrence of physical versus chemical adsorption by comparing the values of the extracted surface charge density. These studies demonstrate that InAs nanowires can produce a multitude of sensor responses for the purpose of developing next generation, multi-dimensional sensor applications. PMID:28714903

Evaluation of seismic acceleration responses of base-isolated and nonisolated structures varying with mechanical characteristics of foundations

Energy Technology Data Exchange (ETDEWEB)

You, Bong; Lee, Jae Han; Ku, Kyung Hoi [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of)

1996-05-01

The evaluation of acceleration responses of isolated and nonisolated structures according to mechanical features of soils is important. The kinds of soils taken in analyses are soft, medium and hard rocks, and a fixed base condition is also taken for the comparison. The horizontal isolation frequency used is 0.5 Hz. The time history analyses of reference power plant using 1940 El Centro horizontal (NS) and vertical earthquakes are performed to investigate the seismic responses varying with soil characteristics for isolated and nonisolated structures. The horizontal acceleration responses of the horizontal isolated-structures show almost similar values irrespective of the various kinds of soils and are largely decreased in the frequency ranges above 2 hz. The vertical natural frequency, 21Hz of high damping rubber bearing does not affect the vertical acceleration responses in case of soft rock, but largely affects in hard rock condition. For nonisolated structures, the acceleration responses are decreased in both horizontal and vertical directions by taking into account the soils in the analysis model. The extent of reduction of acceleration responses is larger in vertical direction than in horizontal one, as the stiffness of rock becomes softer. 8 tabs., 21 figs., 8 refs. (Author) .new.

Evaluation of seismic acceleration responses of base-isolated and nonisolated structures varying with mechanical characteristics of foundations

International Nuclear Information System (INIS)

You, Bong; Lee, Jae Han; Ku, Kyung Hoi

1996-05-01

The evaluation of acceleration responses of isolated and nonisolated structures according to mechanical features of soils is important. The kinds of soils taken in analyses are soft, medium and hard rocks, and a fixed base condition is also taken for the comparison. The horizontal isolation frequency used is 0.5 Hz. The time history analyses of reference power plant using 1940 El Centro horizontal (NS) and vertical earthquakes are performed to investigate the seismic responses varying with soil characteristics for isolated and nonisolated structures. The horizontal acceleration responses of the horizontal isolated-structures show almost similar values irrespective of the various kinds of soils and are largely decreased in the frequency ranges above 2 hz. The vertical natural frequency, 21Hz of high damping rubber bearing does not affect the vertical acceleration responses in case of soft rock, but largely affects in hard rock condition. For nonisolated structures, the acceleration responses are decreased in both horizontal and vertical directions by taking into account the soils in the analysis model. The extent of reduction of acceleration responses is larger in vertical direction than in horizontal one, as the stiffness of rock becomes softer. 8 tabs., 21 figs., 8 refs. (Author) .new

A novel approach for fault detection and classification of the thermocouple sensor in Nuclear Power Plant using Singular Value Decomposition and Symbolic Dynamic Filter

International Nuclear Information System (INIS)

Mandal, Shyamapada; Santhi, B.; Sridhar, S.; Vinolia, K.; Swaminathan, P.

2017-01-01

Highlights: • A novel approach to classify the fault pattern using data-driven methods. • Application of robust reconstruction method (SVD) to identify the faulty sensor. • Analysing fault pattern for plenty of sensors using SDF with less time complexity. • An efficient data-driven model is designed to the false and missed alarms. - Abstract: A mathematical model with two layers is developed using data-driven methods for thermocouple sensor fault detection and classification in Nuclear Power Plants (NPP). The Singular Value Decomposition (SVD) based method is applied to detect the faulty sensor from a data set of all sensors, at the first layer. In the second layer, the Symbolic Dynamic Filter (SDF) is employed to classify the fault pattern. If SVD detects any false fault, it is also re-evaluated by the SDF, i.e., the model has two layers of checking to balance the false alarms. The proposed fault detection and classification method is compared with the Principal Component Analysis. Two case studies are taken from Fast Breeder Test Reactor (FBTR) to prove the efficiency of the proposed method.

Study on the dose response characteristics of a scanning liquid ion-chamber electronic portal imaging device

CERN Document Server

Ma Shao Gang; Song Yi Xin

2002-01-01

Objective: To study the dose response characteristics and the influence factors such as gantry angle, field size and acquisition mode on the dosimetric response curves, when using a scanning liquid ion-chamber electronic portal imaging device (EPID) for dose verification. Methods: All experiments were carried out on a Varian 600 C/D accelerator (6 MV X-ray) equipped with a Varian PortalVision sup T sup M MK2 type EPID. To obtain the dose response curve, the relationship between the incident radiation intensity to the detector and the pixel value output from the EPID were established. Firstly, the different dose rates of 6 MV X-rays were obtained by varying SSD. Secondly, three digital portal images were acquired for each dose rate using the EPID and averaged to avoid the influence of the dose rate fluctuations of the accelerator. The pixel values of all images were read using self-designed image analysis software, and and average for a region consisting of 11 x 11 pixels around the center was taken as the res...

Heat transfer and flow region characteristics study in a non-annular channel between rotor and stator

Directory of Open Access Journals (Sweden)

Nili-Ahmadabadi M.

2012-01-01

Full Text Available This paper will present the results of the experimental investigation of heat transfer in a non-annular channel between rotor and stator similar to a real generator. Numerous experiments and numerical studies have examined flow and heat transfer characteristics of a fluid in an annulus with a rotating inner cylinder. In the current study, turbulent flow region and heat transfer characteristics have been studied in the air gap between the rotor and stator of a generator. The test rig has been built in a way which shows a very good agreement with the geometry of a real generator. The boundary condition supplies a non-homogenous heat flux through the passing air channel. The experimental devices and data acquisition method are carefully described in the paper. Surface-mounted thermocouples are located on the both stator and rotor surfaces and one slip ring transfers the collected temperature from rotor to the instrument display. The rotational speed of rotor is fixed at three under: 300rpm, 900 rpm and 1500 rpm. Based on these speeds and hydraulic diameter of the air gap, the Reynolds number has been considered in the range: 4000characteristics.

Experimental study on combustion characteristics of sodium fire in a columnar flow

International Nuclear Information System (INIS)

Zhang Zhigang; Peng Kangwei; Guo Ming; Huo Yan

2014-01-01

In the operation of the sodium-cooled fast reactor, the accident caused by the leakage and combustion of liquid sodium is common and frequent in sodium-related facilities. This paper is based on an experimental study of sodium fire in a columnar flow, which was carried out to focus on the burning characteristics by analyzing the temperature fields in the burner. The injection of 200°C liquid sodium with the flux of 0.5 m 3 /h was poured into a 7.9 m 3 volume stainless steel cylindrical burner to shape a sodium fire, and the data of temperature fields in the burner have been collected by dozens of thermocouples which are laid in the combustion space and sodium collection plate. These results show that the sodium fire in a columnar flow is composed of the foregoing centered columnar fire, the subsequent spray fire caused by atomization and the pool fire on the collection plate. The temperature close to the burning sodium flow maximally reaches up to 950°C. The radial temperatures apart from the sodium flow are relatively low and generally about 200°C, and maximally just 300°C even when close to the sodium collection plate. The maximum temperature of the burning sodium dropping on the collection plate rises in the center of plate, about 528°C. This study is helpful to evaluate the combustion characteristics, formation process and composing forms of the sodium fire in the sodium-related facilities. (author)

Change of ENSO characteristics in response to global warming

Science.gov (United States)

Sun, X.; Xia, Y.; Yan, Y.; Feng, W.; Huang, F.; Yang, X. Q.

2017-12-01

By using datasets of HadISST monthly SST from 1895 to 2014 and 600-year simulations of two CESM model experiments with/without doubling of CO2 concentration, ENSO characteristics are compared pre- and post- global warming. The main results are as follows. Due to global warming, the maximum climatological SST warming occurs in the tropical western Pacific (La Niña-like background warming) and the tropical eastern Pacific (El Niño-like background warming) for observations and model, respectively, resulting in opposite zonal SST gradient anomalies in the tropical Pacific. The La Niña-like background warming induces intense surface divergence in the tropical central Pacific, which enhances the easterly trade winds in the tropical central-western Pacific and shifts the strongest ocean-atmosphere coupling westward, correspondingly. On the contrary, the El Niño-like background warming causes westerly winds in the whole tropical Pacific and moves the strongest ocean-atmosphere coupling eastward. Under the La Niña-like background warming, ENSO tends to develop and mature in the tropical central Pacific, because the background easterly wind anomaly weakens the ENSO-induced westerly wind anomaly in the tropical western Pacific, leading to the so-called "Central Pacific ENSO (CP ENSO)". However, the so-called "Eastern Pacific ENSO (EP ENSO)" is likely formed due to increased westerly wind anomaly by the El Niño-like background warming. ENSO lifetime is significantly extended under both the El Niño-like and the La Niña-like background warmings, and especially, it can be prolonged by up to 3 months in the situation of El Niño-like background warming. The prolonged El Nino lifetime mainly applies to extreme El Niño events, which is caused by earlier outbreak of the westerly wind bursts, shallower climatological thermocline depth and weaker "discharge" rate of the ENSO warm signal in response to global warming. Results from both observations and the model also show that

Response characteristics of vegetation and soil environment to permafrost degradation in the upstream regions of the Shule River Basin

International Nuclear Information System (INIS)

Chen Shengyun; Liu Wenjie; Qin Xiang; Liu Yushuo; Ren Jiawen; Qin Dahe; Zhang Tongzuo; Hu Fengzu; Chen Kelong

2012-01-01

Permafrost degradation exhibits striking and profound influences on the alpine ecosystem, and response characteristics of vegetation and soil environment to such degradation inevitably differ during the entire degraded periods. However, up to now, the related research is lacking in the Qinghai–Tibetan Plateau (QTP). For this reason, twenty ecological plots in the different types of permafrost zones were selected in the upstream regions of the Shule River Basin on the northeastern margin of the QTP. Vegetation characteristics (species diversity, community coverage and biomass etc) and topsoil environment (temperature (ST), water content (SW), mechanical composition (SMC), culturable microorganism (SCM), organic carbon (SOC) and total nitrogen (TN) contents and so on), as well as active layer thickness (ALT) were investigated in late July 2009 and 2010. A spatial–temporal shifts method (the spatial pattern that is represented by different types of permafrost shifting to the temporal series that stands for different stages of permafrost degradation) has been used to discuss response characteristics of vegetation and topsoil environment throughout the entire permafrost degradation. The results showed that (1) ST of 0–40 cm depth and ALT gradually increased from highly stable and stable permafrost (H-SP) to unstable permafrost (UP). SW increased initially and then decreased, and SOC content and the quantities of SCM at a depth of 0–20 cm first decreased and then increased, whereas TN content and SMC showed obscure trends throughout the stages of permafrost degradation with a stability decline from H-SP to extremely unstable permafrost (EUP); (2) further, species diversity, community coverage and biomass first increased and then decreased in the stages from H-SP to EUP; (3) in the alpine meadow ecosystem, SOC and TN contents increased initially and then decreased, soil sandy fractions gradually increased with stages of permafrost degradation from substable (SSP

Data report on series 6 reflood experiment

International Nuclear Information System (INIS)

Iguchi, Tadashi; Murao, Yoshio; Sudoh, Takashi; Sudo, Yukio; Sugimoto, Jun

1979-03-01

Series 6 reflood experiments (experiment with 4 x 4 indirectly heated rods) were carried out from March to June 1978. The purpose of the experiments was: 1) to observe overall reflood phenomena in a 4 x 4 indirectly heated heater rod bundle with thermocouples inbedded completely in the cladding, 2) to examine the quench characteristics at low flooding rate, 3) to measure steady-state differential pressures in the core, 4) to investigate the heat transfer coefficients before quenching, 5) to investigate the water effluence behavior at outlet of the core, 6) to investigate the effect of a non-heated rod, and 7) to examine the response characteristics of the system at forced oscillating flooding rate. Described are the experimental conditions and the results (cladding temperatures, pressure differences and flow rates) in the constant flooding rate experiments in series 6 experiment. (author)

Postural Response Signal Characteristics Identified by Method of Developed Statokinesigram

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Barbolyas Boris

2015-12-01

Full Text Available Human postural system is taken as complex biological system with specific input and output time characteristics, in this study. Evaluation of measured output characteristics is useful in medical diagnostics or in describing postural system disorders. System theory principle provide suitable basis for postural signals analysis. Participating volunteers were instructed to maintain quiet upright stance posture on firm support surface of stabilometric platform for 60s. Postural system actuation was realized by vibration stimuli applied bilaterally on Achilles tendons for 20s. Postural reaction signal, its time profile and static and dynamic characteristics were evaluated by Method of Developed Statokinesigram Trajectory (MDST.

Report on series 3 reflood experiment

International Nuclear Information System (INIS)

Murao, Yoshio; Iguchi, Tadashi; Sudoh, Takashi; Sudo, Yukio; Sugimoto, Jun

1977-03-01

Series 3 reflood experiment was carried out from December 1975 to January 1976. The purpose was to confirm temperature response and durability of the improved thermocouple installation and to examine system effect with parameters, flow housing temperature and primary loop flow resistance. The results are : 1) The improved thermocouples installation still has some problems, but is generally satisfactory up to 1000 0 C. 2) The flow housing temperature has large influence on the reflood phenomena, especially oscillation. 3) The primary loop resistance determines the flooding rate, and so influences the reflood phenomena. (auth.)

Biometrical characteristics and physiological responses to a local cold exposure of the extremities.

Science.gov (United States)

Savourey, G; Sendowski, I; Bittel, J

1996-01-01

The aim of this study was firstly to describe the physiological responses observed in 19 subjects during immersion of the arm up to the elbow in water at 5 degrees C (5 min) followed by a 10-min recovery and secondly, to correlate the observed physiological responses with biometrical characteristics of the subjects (maximal oxygen uptake, VO2max, percentage fat content of whole body, BF, and arm, forearm and hand skinfold thickness). The results showed that the time courses of changes in forearm and hand skin temperature were different compared to those of finger skin temperatures both during local cooling and during rewarming (P immersion, decreased hand skin temperature was correlated to VO2max (r = 0.45, P < or = 0.05) whereas decreased forearm skin temperature was correlated both to VO2max (r = 0.44, P < or = 0.05) and to skinfold thickness (r = -0.44, P < or = 0.05) but not to BF. During the beginning of the recovery period only, outside, inside forearm and hand skin temperatures were related to VO2max (r = 0.54, P < or = 0.05; r = 0.66, P < or = 0.01 and r = 0.45, P < or = 0.05, respectively) and all the skinfold thicknesses (r = -0.47 to -0.71, P < or = 0.05). It was concluded that the local skin temperature profiles differed according to the upper limb segment both during cooling and during early rewarming. Moreover, VO2max and upper limb skinfold thickness but not BF did influence the forearm and hand skin temperature changes during cooling and early rewarming but not the finger skin temperature changes and cardiovascular responses.

The influence of supply and sewerage area characteristics on water and sewerage companies responses to the Water Framework Directive.

Science.gov (United States)

Spiller, M; McIntosh, B S; Seaton, R A F

2009-01-01

Using the example of raw water quality this paper examines the relationship between different spatial characteristics (geographical and physical properties) of Water and Sewerage Companies (WaSCs) supply and sewage areas and response to the Water Framework Directive. Results were obtained from thematic analysis and content analysis of 14 interviews with WaSCs representatives. Principal component analysis and cluster analysis of 51 WaSCs business function characteristics was employed to derive groups of similar WaSCs. Results indicate that there is difference in how WaSCs approach raw water quality issues. It appears that small WaSCs with relatively large agricultural areas in their supply catchments are more likely to seek managerial solutions to raw water quality problems.

Content Validity and Psychometric Characteristics of the "Knowledge about Older Patients Quiz" for Nurses Using Item Response Theory.

Science.gov (United States)

Dikken, Jeroen; Hoogerduijn, Jita G; Kruitwagen, Cas; Schuurmans, Marieke J

2016-11-01

To assess the content validity and psychometric characteristics of the Knowledge about Older Patients Quiz (KOP-Q), which measures nurses' knowledge regarding older hospitalized adults and their certainty regarding this knowledge. Cross-sectional. Content validity: general hospitals. Psychometric characteristics: nursing school and general hospitals in the Netherlands. Content validity: 12 nurse specialists in geriatrics. Psychometric characteristics: 107 first-year and 78 final-year bachelor of nursing students, 148 registered nurses, and 20 nurse specialists in geriatrics. Content validity: The nurse specialists rated each item of the initial KOP-Q (52 items) on relevance. Ratings were used to calculate Item-Content Validity Index and average Scale-Content Validity Index (S-CVI/ave) scores. Items with insufficient content validity were removed. Psychometric characteristics: Ratings of students, nurses, and nurse specialists were used to test for different item functioning (DIF) and unidimensionality before item characteristics (discrimination and difficulty) were examined using Item Response Theory. Finally, norm references were calculated and nomological validity was assessed. Content validity: Forty-three items remained after assessing content validity (S-CVI/ave = 0.90). Psychometric characteristics: Of the 43 items, two demonstrating ceiling effects and 11 distorting ability estimates (DIF) were subsequently excluded. Item characteristics were assessed for the remaining 30 items, all of which demonstrated good discrimination and difficulty parameters. Knowledge was positively correlated with certainty about this knowledge. The final 30-item KOP-Q is a valid, psychometrically sound, comprehensive instrument that can be used to assess the knowledge of nursing students, hospital nurses, and nurse specialists in geriatrics regarding older hospitalized adults. It can identify knowledge and certainty deficits for research purposes or serve as a tool in educational

Multi-response optimization of machining characteristics in ultrasonic machining of WC-Co composite through Taguchi method and grey-fuzzy logic

Directory of Open Access Journals (Sweden)

Ravi Pratap Singh

2018-01-01

Full Text Available This article addresses the application of grey based fuzzy logic coupled with Taguchi’s approach for optimization of multi performance characteristics in ultrasonic machining of WC-Co composite material. The Taguchi’s L-36 array has been employed to conduct the experimentation and also to observe the influence of different process variables (power rating, cobalt content, tool geometry, thickness of work piece, tool material, abrasive grit size on machining characteristics. Grey relational fuzzy grade has been computed by converting the multiple responses, i.e., material removal rate and tool wear rate obtained from Taguchi’s approach into a single performance characteristic using grey based fuzzy logic. In addition, analysis of variance (ANOVA has also been attempted in a view to identify the significant parameters. Results revealed grit size and power rating as leading parameters for optimization of multi performance characteristics. From the microstructure analysis, the mode of material deformation has been observed and the critical parameters (i.e., work material properties, grit size, and power rating for the deformation mode have been established.

Jealousy at work: The role of rivals' characteristics.

Science.gov (United States)

Zurriaga, Rosario; González-Navarro, Pilar; Buunk, Abraham Pieter; Dijkstra, Pieternel

2018-03-26

The present study examined rival characteristics that may evoke jealousy in the workplace, differences between men and women in this regard, and the relationship between jealousy responses and intrasexual competitiveness and social comparison orientation. Participants were 426 male and female employees. By means of a questionnaire, participants were presented with a jealousy-evoking scenario after which jealousy responses to 24 rival characteristics were assessed. Findings showed that a rival's social communal attributes evoked highest levels of jealousy, and that, compared to men, women reported more jealousy in response to a rival's physical attractiveness. Overall, as individuals had higher scores on intrasexual competitiveness and social comparison orientation, they also experienced more jealousy in response to their rival, regardless of his or her characteristics. These findings suggest that those characteristics that are highly valued in employees may backfire when employees perceive co-workers as rivals. © 2018 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Data report on reflood experiment, 8

International Nuclear Information System (INIS)

Sugimoto, Jun; Murao, Yoshio; Iguchi, Tadashi; Sudoh, Takashi; Sudo, Yukio

1979-03-01

Heat transfer behavior in series 6 reflood experiment is reported including test conditions and data processing. To develop an analysis code, the purpose of the series 6 reflood experiment was as follows: (1) Overall reflood phenomena in a 4 x 4 array indirectly heated heater rod bundle. Sheathed thermocouples were completely embedded in the heater rod cladding. (2) Quench characteristics at low flooding rate. (3) Differential pressure response in the core. (4) Heat transfer coefficients downstream of the quench point. (5) Water effluence behavior at outlet of the core. (6) Effect of non-heated rod in the core. (7) System response under intermittent-flow-rate core forced injection. The tests were in three groups according to the water injection methods to the core: (1) Constant-flow-rate core forced injection, (2) intermittent-flow-rate core forced injection, and (3) system effect test. (author)

Performance characteristics of the Mayo/IBM PACS

Science.gov (United States)

Persons, Kenneth R.; Gehring, Dale G.; Pavicic, Mark J.; Ding, Yingjai

1991-07-01

The Mayo Clinic and IBM (at Rochester, Minnesota) have jointly developed a picture archiving system for use with Mayo's MRI and Neuro CT imaging modalities. The communications backbone of the PACS is a portion of the Mayo institutional network: a series of 4-Mbps token rings interconnected by bridges and fiber optic extensions. The performance characteristics of this system are important to understand because they affect the response time a PACS user can expect, and the response time for non-PACS users competing for resources on the institutional network. The performance characteristics of each component and the average load levels of the network were measured for various load distributions. These data were used to quantify the response characteristics of the existing system and to tune a model developed by North Dakota State University Department of Computer Science for predicting response times of more complex topologies.

Intramuscular Heating Characteristics of Multihour Low-Intensity Therapeutic Ultrasound.

Science.gov (United States)

Rigby, Justin H; Taggart, Rebecca M; Stratton, Kelly L; Lewis, George K; Draper, David O

2015-11-01

The heating characteristics of a stationary device delivering sustained acoustic medicine with low-intensity therapeutic ultrasound (LITUS) are unknown. To measure intramuscular (IM) heating produced by a LITUS device developed for long-duration treatment of musculoskeletal injuries. Controlled laboratory study. University research laboratory. A total of 26 healthy volunteers (16 men, 10 women; age = 23.0 ± 2.1 years, height = 1.74 ± 0.09 m, mass = 73.48 ± 14.65 kg). Participants were assigned randomly to receive active (n = 20) or placebo (n = 6) LITUS at a frequency of 3 MHz and an energy intensity of 0.132 W/cm(2) continuously for 3 hours with a single transducer or dual transducers on the triceps surae muscle. We measured IM temperature using thermocouples inserted at 1.5- and 3-cm depths into muscle. Temperatures were recorded throughout treatment and 30 minutes posttreatment. We used 2-sample t tests to determine the heating curve of the LITUS treatment and differences in final temperatures between depth and number of transducers. A mild IM temperature increase of 1 °C was reached 10 ± 5 minutes into the treatment, and a more vigorous temperature increase of 4 °C was reached 80 ± 10 minutes into the treatment. The maximal steady-state IM temperatures produced during the final 60 minutes of treatment at the 1.5-cm depth were 4.42 °C ± 0.08 °C and 3.92 °C ± 0.06 °C using 1 and 2 transducers, respectively. At the 3.0-cm depth, the maximal steady-state IM temperatures during the final 60 minutes of treatment were 3.05 °C ± 0.09 °C and 3.17 °C ± 0.05 °C using 1 and 2 transducers, respectively. We observed a difference between the temperatures measured at each depth (t78 = -2.45, P = .02), but the number of transducers used to generate heating was not different (t78 = 1.79, P = .08). The LITUS device elicited tissue heating equivalent to traditional ultrasound but could be sustained for multiple hours. It is a safe and effective alternative tool

Corporate Responsibility

DEFF Research Database (Denmark)

Waddock, Sandra; Rasche, Andreas

2015-01-01

We define and discuss the concept of corporate responsibility. We suggest that corporate responsibility has some unique characteristics, which makes it different from earlier conceptions of corporate social responsibility. Our discussion further shows commonalities and differences between corporate...... responsibility and related concepts, such as corporate citizenship and business ethics. We also outline some ways in which corporations have implemented corporate responsibility in practice....

Clinical and radiological characteristics of central pulmonary adenocarcinoma: a comparison with central squamous cell carcinoma and small cell lung cancer and the impact on treatment response

Directory of Open Access Journals (Sweden)

Wang Z

2018-05-01

Full Text Available Zhe Wang,1,2 Minghuan Li,2 Yong Huang,3 Li Ma,3 Hui Zhu,2 Li Kong,2 Jinming Yu2 1School of Medicine, Shandong University, Jinan, Shandong, China; 2Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Jinan, Shandong, China; 3Department of Radiology, Shandong Cancer Hospital Affiliated to Shandong University, Jinan, Shandong, China Purpose: The proportion of central pulmonary adenocarcinoma (ADC in central-type lung cancer has been gradually increasing due to the overall increasing incidence of pulmonary ADC. But the clinical and radiological characteristics of central ADCs remain unclear. In this study, we compared the clinical and radiological characteristics of central ADCs with those of small cell lung cancers (SCLCs and squamous cell carcinomas (SQCCs and investigated the impact of these characteristics on patients’ treatment response. Patients and methods: The medical records of 302 consecutive patients with central lung cancer from July 2014 to September 2016 were retrospectively reviewed. There were 99 patients with ADC, 95 with SQCC and 108 with SCLC. Computed tomography images were interpreted by two radiologists. Treatment response was determined by Response Evaluation Criteria In Solid Tumors 1.1. Results: Univariate analyses found that younger age, female sex, no history of smoking, higher levels of carcinoembryonic antigen (CEA, contralateral hilum lymphadenopathy, contralateral lung metastasis, pleural nodules and pleural metastasis to the interlobular fissure were significantly correlated with central ADC. Multivariate logistic regression analyses revealed that compared with central SQCC, female sex, younger age, no history of smoking, higher levels of CEA and contralateral hilum lymphadenopathy were the significantly independent indicators of central pulmonary ADC. Furthermore, compared with central SCLC, younger age, higher levels of CEA and cytokeratin 19 fragment (Cyfra21-1, lower

Evaluation of riser 14 temperature response

International Nuclear Information System (INIS)

OGDEN, D.M.

1999-01-01

The initial sluicing activities of Project WRSS resulted in a two month increase in temperatures as measured by the Riser 14 thermocouple tree of tank 241-C-106. While this increase was anticipated, the maximum temperature was higher than expected. An evaluation was performed to determine if adequate subcooling exists in the waste to continue sluicing activities. It was determined that a minimum of 10 F subcooling exists in the waste and that the higher Riser 14 temperatures were the result of higher than assumed waste saturation temperature

The effect of loading time on flexible pavement dynamic response: a finite element analysis

Science.gov (United States)

Yin, Hao; Solaimanian, Mansour; Kumar, Tanmay; Stoffels, Shelley

2007-12-01

Dynamic response of asphalt concrete (AC) pavements under moving load is a key component for accurate prediction of flexible pavement performance. The time and temperature dependency of AC materials calls for utilizing advanced material characterization and mechanistic theories, such as viscoelasticity and stress/strain analysis. In layered elastic analysis, as implemented in the new Mechanistic-Empirical Pavement Design Guide (MEPDG), the time dependency is accounted for by calculating the loading times at different AC layer depths. In this study, the time effect on pavement response was evaluated by means of the concept of “pseudo temperature.” With the pavement temperature measured from instrumented thermocouples, the time and temperature dependency of AC materials was integrated into one single factor, termed “effective temperature.” Via this effective temperature, pavement responses under a transient load were predicted through finite element analysis. In the finite element model, viscoelastic behavior of AC materials was characterized through relaxation moduli, while the layers with unbound granular material were assumed to be in an elastic mode. The analysis was conducted for two different AC mixtures in a simplified flexible pavement structure at two different seasons. Finite element analysis results reveal that the loading time has a more pronounced impact on pavement response in the summer for both asphalt types. The results indicate that for reasonable prediction of dynamic response in flexible pavements, the effect of the depth-dependent loading time on pavement temperature should be considered.

The effects of pre-etching time on the characteristic responses of electrochemically etched CR-39 neutron dosimeters

International Nuclear Information System (INIS)

Sohrabi, M.; Khoshnoodi, M.

1986-01-01

The effects of pre-etching time (PET) or duration of etching of fast-neutron-induced-recoil tracks in CR-39 in 6N KOH at 60 0 C on electrochemical etching neutron characteristic responses; i.e. sensitivity and mean recoil track diameter (MRTD) versus KOH normality up to 18N are investigated in this paper. Six sets of responses for PETs of 0, 1, 2, 3, 4, and 5 hours were obtained by using our new multi-chamber ECE (MCECE) system which reduced total operation time to about 6% of the time usually required when single-chamber ECE systems are used. The sensitivity response for zero PET showed a broad plateau and a high sensitivity low-LET peak around 16N. By increasing PET, another peak was also developed around 5N leading to 'double-humped' responses with two maximums around 5N and 16N, and a minimum around 11N. On the other hand, the MRTD responses for all PETs studied showed the same general trend with maximums around 11N. In this paper, shape of tracks under different conditions are also investigated, new optimum conditions such as KOH concentrations of 5, 11, and 15N at 25 0 C, with or without pre-etching, are recommended for tracks of lower-LET recoils including possibly protons, and alpha particle tracks over a broad energy range, and the efficiency of the MCECE system is also demonstrated. (author)

Simulation of a welding process in polyduct pipelines resolved with a finite elements computational model. Comparison with analytical solutions and tests with thermocouples

International Nuclear Information System (INIS)

Sanzi, H; Elvira, G; Kloster, M; Asta, E; Zalazar, M

2006-01-01

All welding processes induce deformations and thermal tensions, which must be evaluated correctly since they can influence a component's structural integrity. This work determines the distribution of temperatures that develop during a manual welding process with shielded electrodes (SMAW), on the circumference seam of a pipe for use in polyducts. A simplified model of Finite Elements (FEA) using three dimensional solids is proposed for the study. The analysis considers that while the welding process is underway, no heat is lost into the environment, that is, adiabatic conditions are considered, and the transformations produced in the material due to phase changes do not produce modifications in the properties of the supporting or base materials. The results of the simulation are compared with those obtained by recent analytical studies developed by different investigators, such as Nguyen, Ohta, Matsuoka, Suzuki and Taeda, where a continuously moving three dimensional double ellipsoidal source was used. The results are then compared with the experimental results by measuring with thermocouples. This study reveals the sensitivity and the validity of the proposed computer model, and in a second stage optimizes the engineering times for the resolution of a problem like the one presented in order to design the corresponding welding procedure (CW)

Differences in characteristics and patient-reported questionnaire responses in patients who choose non-surgical versus surgical treatment for severe hip osteoarthritis

DEFF Research Database (Denmark)

Have, Mads; Overgaard, Søren; Jensen, Carsten

Background: Preoperative patient characteristics may influence patient choice for participating in RCT’s. Purpose / Aim of Study: This study aimed to compare patient characteristics, level of pain, physical function and joint space width in patients with severe hip osteoarthritis (OA) who accepted...... or refused to participate in a RCT. Materials and Methods: In this prospective cohort study a total of 137 patients with primary hip OA were asked to choose between surgical or non- surgical treatment. We then compared the characteristics of each patient cohort (demographics, pain level and duration......, analgesic use, exercise habits), the radiographic hip OA state and their responses to Hip dysfunction and Osteoarthritis Outcome Score (HOOS, 0-100) and European Quality of Life Scale (EQ-5D-5L) questionnaires. Findings / Results: The between-group HOOS scores were significantly different in three out...

Estimation of piping temperature fluctuations based on external strain measurements

International Nuclear Information System (INIS)

Morilhat, P.; Maye, J.P.

1993-01-01

Due to the difficulty to carry out measurements at the inner sides of nuclear reactor piping subjected to thermal transients, temperature and stress variations in the pipe walls are estimated by means of external thermocouples and strain-gauges. This inverse problem is solved by spectral analysis. Since the wall harmonic transfer function (response to a harmonic load) is known, the inner side signal will be obtained by convolution of the inverse transfer function of the system and of the strain measurement enables detection of internal temperature fluctuations in a frequency range beyond the scope of the thermocouples. (authors). 5 figs., 3 refs

An Analysis on the Characteristic of Multi-response CADIS Method for the Monte Carlo Radiation Shielding Calculation

International Nuclear Information System (INIS)

Kim, Do Hyun; Shin, Chang Ho; Kim, Song Hyun

2014-01-01

It uses the deterministic method to calculate adjoint fluxes for the decision of the parameters used in the variance reductions. This is called as hybrid Monte Carlo method. The CADIS method, however, has a limitation to reduce the stochastic errors of all responses. The Forward Weighted CADIS (FW-CADIS) was introduced to solve this problem. To reduce the overall stochastic errors of the responses, the forward flux is used. In the previous study, the Multi-Response CADIS (MR-CAIDS) method was derived for minimizing sum of each squared relative error. In this study, the characteristic of the MR-CADIS method was evaluated and compared with the FW-CADIS method. In this study, how the CADIS, FW-CADIS, and MR-CADIS methods are applied to optimize and decide the parameters used in the variance reduction techniques was analyzed. The MR-CADIS Method uses a technique that the sum of squared relative error in each tally region was minimized to achieve uniform uncertainty. To compare the simulation efficiency of the methods, a simple shielding problem was evaluated. Using FW-CADIS method, it was evaluated that the average of the relative errors was minimized; however, MR-CADIS method gives a lowest variance of the relative errors. Analysis shows that, MR-CADIS method can efficiently and uniformly reduce the relative error of the plural response problem than FW-CADIS method

Alpha-particle response characteristics of CR-39

International Nuclear Information System (INIS)

Abou El-Khier, A.A.; Gaber, M.; El-Khatib, A.M.; Fawzy, M.A.

1987-01-01

The form of the response curve of the polycarbonate CR-39 for α-particles at relatively low energies has been established. The investigation included measurements of both bulk- and track-etch rates. The latter was measured as a function of α-particle energies. (author)

Patient Characteristics Associated With a Successful Response to Nurse-Led Care Programs Targeting the Oldest-Old: A Comparison of Two RCTs.

Science.gov (United States)

Bleijenberg, Nienke; Imhof, Lorenz; Mahrer-Imhof, Romy; Wallhagen, Margaret I; de Wit, Niek J; Schuurmans, Marieke J

2017-06-01

To improve the effectiveness of community-based care programs, especially those targeting the oldest-old population (80+), data are needed that elucidate those factors associated with a successful response to the intervention. Two comparable nurse-led care programs have been evaluated in two large randomized controlled trials (RCTs), one in Switzerland and one in the Netherlands. To identify common patient characteristics that are related to a successful response to proactive nurse-led care, we explored if and to what extent, identical factors were present in both study populations. A secondary data analysis using trial data from the intervention group of both RCTs was conducted. The study sample consisted 461 older adults, 230 from the U-PROFIT trial (the Netherlands) and 231 from the HPC trial (Switzerland). The mean age of the total sample was 85.1 years (SD 3.7). The UPROFIT intervention, delivered by registered nurses, included a frailty assessment and a comprehensive geriatric assessment (CGA) at home followed by an individualized evidence-based care plan, care coordination, and follow-up. The HCP intervention was delivered by advanced practice nurses consisting of four home visits and three phone calls, and was guided by the principles of health promotion, empowerment, partnership, and family-centeredness. A successful response was defined as "stable" or "no decline" in daily functioning at follow-up. Daily functioning was measured with 13 items of activities of daily living and instrumental activities of daily living. Multivariate logistic regression models were applied to calculate the association between individual characteristics and a successful response. Almost half of the participants in the U-PROFIT trial (50.9%), and two-thirds (65.7%) of the participants in the HCP trial had a successful response at follow-up. Fewer comorbidities and a better self-rated health had the strongest predictive value for benefiting from the intervention (OR = 0.83 [95

Molecular characteristics of hemoglobins in blood clam and their immune responses to bacterial infection.

Science.gov (United States)

Xu, Bin; Zhang, Yanan; Jing, Zhao; Fan, Tingjun

2017-06-01

Bivalve hemoglobins have antibacterial activities, while the underlying mechanisms remain poorly understood. In our study, three full-length cDNAs of hemoglobins from blood clam skHbs were obtained, encoding putative polypeptides of 147, 150, and 152 amino acids, respectively. Predicted advanced protein structures showed that the skHbs had amphipathic antibacterial structures, displayed the typical structural characteristics of proteins with globin-like fold containing numerous alpha-helixes, and forming a homodimeric skHbI and a heterotetrameric skHbII complex. After injected with alive and heat-killed Gram-positive bacteria Bacillus subtilis, the mRNA levels of skHbI and skHbII were both significantly upregulated through increasing the expression of peptidoglycan recognition protein-like (PGRP-like) protein and Toll-like receptor (TLR-like) protein induced by peptidoglycan on the surface of the bacteria, but there were no obvious differences in their protein levels. Besides, reactive oxygen species (ROS) was detected to participate in the resistance to B. subtilis. These implied that skHbs could involve in the innate immune responses to Gram-positive bacterial infection directly with their amphipathic structures and indirectly by increasing ROS production through PGRP triggering Toll pathway. In conclusion, our findings reveal the structural characteristics of skHbs and their mechanism against Gram-positive bacteria thereby providing the molecular evidence for fundamental innate antibacterial activities by invoking respiratory proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

An intelligent instrument for measuring exhaust temperature of marine engine

Science.gov (United States)

Ma, Nan-Qi; Su, Hua; Liu, Jun

2006-12-01

Exhaust temperature of the marine engine is commonly measured through thermocouple. Measure deviation will occur after using the thermocouple for some time due to nonlinearity of thermocouple itself, high temperature and chemical corrosion of measure point. Frequent replacement of thermocouple will increase the operating cost. This paper designs a new intelligent instrument for solving the above-mentioned problems of the marine engine temperature measurement, which combines the conventional thermocouple temperature measurement technology and SCM(single chip microcomputer). The reading of the thermocouple is simple and precise and the calibration can be made automatically and manually.

'Nordic' Hamstrings Exercise - Engagement Characteristics and Training Responses

OpenAIRE

Iga, J; Fruer, C S; Deighan, Martine A; De Ste Croix, Mark B; James, David V

2012-01-01

The present study examined the neuromuscular activation characteristics of the hamstrings during the 'Nordic' hamstrings exercise (NHE) and changes in the eccentric strength of the knee flexors with NHE training. Initially, the normalised root mean square electromyographic (EMG) activity of the hamstrings of both limbs during various phases (90-61 degrees, 60-31 degrees and 30-0 degrees of knee extension) of the NHE were determined in 18 soccer players. Subsequently participants were randomly...

Optimized balance rehabilitation training strategy for the elderly through an evaluation of balance characteristics in response to dynamic motions

Science.gov (United States)

Jung, HoHyun; Chun, Keyoung Jin; Hong, Jaesoo; Lim, Dohyung

2015-01-01

Balance is important in daily activities and essential for maintaining an independent lifestyle in the elderly. Recent studies have shown that balance rehabilitation training can improve the balance ability of the elderly, and diverse balance rehabilitation training equipment has been developed. However, there has been little research into optimized strategies for balance rehabilitation training. To provide an optimized strategy, we analyzed the balance characteristics of participants in response to the rotation of a base plate on multiple axes. Seven male adults with no musculoskeletal or nervous system-related diseases (age: 25.5±1.7 years; height: 173.9±6.4 cm; body mass: 71.3±6.5 kg; body mass index: 23.6±2.4 kg/m2) were selected to investigate the balance rehabilitation training using customized rehabilitation equipment. Rotation of the base plate of the equipment was controlled to induce dynamic rotation of participants in the anterior–posterior, right-diagonal, medial–lateral, and left-diagonal directions. We used a three-dimensional motion capture system employing infrared cameras and the Pedar Flexible Insoles System to characterize the major lower-extremity joint angles, center of body mass, and center of pressure. We found statistically significant differences between the changes in joint angles in the lower extremities in response to dynamic rotation of the participants (P0.05). These results indicate that optimizing rotation control of the base plate of balance rehabilitation training equipment to induce anterior–posterior and medial–lateral dynamic rotation preferentially can lead to effective balance training. Additional tests with varied speeds and ranges of angles of base plate rotation are expected to be useful as well as an analysis of the balance characteristics considering a balance index that reflects the muscle activity and cooperative characteristics. PMID:26508847

Comparative characteristic of transmembrane currents and caffeine-induced responses of intact and irradiated small intestine smooth muscle cells

International Nuclear Information System (INIS)

Stepanov, Yu.V.; Gordienko, D.V.; Preobrazhenskaya, T.D.; Stepanova, L.I.; Vojtsitskij, V.M.

1994-01-01

A comparative investigation of transmembrane ion currents and caffeine-induced responses of single smooth muscle cells isolated from the circular layer of rat small intestine was curried out by the method of 'patch-clamp'. No reliable difference in potential-dependent and amplitude-kinetic characteristics of transmembrane ion currents in cells of intact and irradiated with dose of 3 Gy rats was revealed. In cells of irradiated animals external application of caffeine (4 mM) was not accompanied by strong quick-inactivated transient Ca 2+ -dependent potassium current as in control

Thermoluminescent characteristics of ZrO2:Nd films

International Nuclear Information System (INIS)

Vera B, G.; Rivera M, T.; Azorin N, J.; Falcony G, C.; Garcia H, M.; Martinez S, E.

2002-01-01

In this work it is exposed the obtained results after analysing the photo luminescent and thermoluminescent characteristics of activated zirconium oxide with neodymium (ZrO 2 :Nd) and its possible application in the UV radiation dosimetry. The realized experiments had as objective to study the characteristics such as the optimum thermal erased treatment, the influence of light on the response, the response depending on the wavelength, the fadeout of the information, the temperature effect, the response depending on the time and the recurring of the response. The results show that the ZrO 2 :Nd is a promising material to be used as Tl dosemeter for the UV radiation. (Author)

Advanced Test Reactor National Scientific User Facility (ATR NSUF) Monthly Report December 2014

Energy Technology Data Exchange (ETDEWEB)

Renae Soelberg

2014-12-01

• PNNL has completed sectioning of the U.C. Berkeley hydride fuel rodlet 1 (highest burn-up) and is currently polishing samples in preparation for optical metallography. • A disk was successfully sectioned from rodlet 1 at the location of the internal thermocouple tip as desired. The transition from annular pellet to solid pellet is verified by the eutectic-filled inner cavity located on the back face of this disk (top left) and the solid front face (bottom left). Preliminary low-resolution images indicate interesting sample characteristics in the eutectic surrounding the rodlet at the location of the outer thermocouple tip (right). This sample has been potted and is currently being polished for high-resolution optical microscopy and subsequent SEM analysis. (See images.)

Very High Output Thermoelectric Devices Based on ITO Nanocomposites

Science.gov (United States)

Fralick, Gustave; Gregory, Otto J.

2009-01-01

A material having useful thermoelectric properties was synthesized by combining indium-tin-oxide (ITO) with a NiCoCrAlY alloy/alumina cermet. This material had a very large Seebeck coefficient with electromotive-force-versustemperature behavior that is considered to be excellent with respect to utility in thermocouples and other thermoelectric devices. When deposited in thin-film form, ceramic thermocouples offer advantages over precious-metal (based, variously, on platinum or rhodium) thermocouples that are typically used in gas turbines. Ceramic thermocouples exhibit high melting temperatures, chemical stability at high temperatures, and little or no electromigration. Oxide ceramics also resist oxidation better than metal thermocouples, cost substantially less than precious-metal thermocouples, and, unlike precious-metal thermocouples, do not exert catalytic effects.

Response Strategies and Response Styles in Cross-Cultural Surveys

NARCIS (Netherlands)

Morren, M.H.; Gelissen, J.P.T.M.; Vermunt, J.K.

2012-01-01

This article addresses the following research questions: Do respondents participating in cross-cultural surveys differ in their response style when responding to attitude statements? If so, are characteristics of the response process associated with their ethnicity and generation of immigration? To

Use of GLM approach to assess the responses of tropical trees to urban air pollution in relation to leaf functional traits and tree characteristics.

Science.gov (United States)

Mukherjee, Arideep; Agrawal, Madhoolika

2018-05-15

Responses of urban vegetation to air pollution stress in relation to their tolerance and sensitivity have been extensively studied, however, studies related to air pollution responses based on different leaf functional traits and tree characteristics are limited. In this paper, we have tried to assess combined and individual effects of major air pollutants PM 10 (particulate matter ≤ 10 µm), TSP (total suspended particulate matter), SO 2 (sulphur dioxide), NO 2 (nitrogen dioxide) and O 3 (ozone) on thirteen tropical tree species in relation to fifteen leaf functional traits and different tree characteristics. Stepwise linear regression a general linear modelling approach was used to quantify the pollution response of trees against air pollutants. The study was performed for six successive seasons for two years in three distinct urban areas (traffic, industrial and residential) of Varanasi city in India. At all the study sites, concentrations of air pollutants, specifically PM (particulate matter) and NO 2 were above the specified standards. Distinct variations were recorded in all the fifteen leaf functional traits with pollution load. Caesalpinia sappan was identified as most tolerant species followed by Psidium guajava, Dalbergia sissoo and Albizia lebbeck. Stepwise regression analysis identified maximum response of Eucalyptus citriodora and P. guajava to air pollutants explaining overall 59% and 58% variability's in leaf functional traits, respectively. Among leaf functional traits, maximum effect of air pollutants was observed on non-enzymatic antioxidants followed by photosynthetic pigments and leaf water status. Among the pollutants, PM was identified as the major stress factor followed by O 3 explaining 47% and 33% variability's in leaf functional traits. Tolerance and pollution response were regulated by different tree characteristics such as height, canopy size, leaf from, texture and nature of tree. Outcomes of this study will help in urban forest

Time-response characteristic and potential biomarker identification of heavy metal induced toxicity in zebrafish.

Science.gov (United States)

Yin, Jian; Wang, Ai-Ping; Li, Wan-Fang; Shi, Rui; Jin, Hong-Tao; Wei, Jin-Feng

2018-01-01

The present work aims to explore the time-response (from 24 h to 96 h) characteristic and identify early potential sensitive biomarkers of copper (Cu) (as copper chloride dihydrate), cadmium (Cd) (as cadmium acetate), lead (Pb) (as lead nitrate) and chromium (Cr) (as potassium dichromate) exposure in adult zebrafish, focusing on reactive oxygen species (ROS), SOD activity, lipid peroxidation and gene expression related to oxidative stress and inflammatory response. Furthermore, the survival rate decreased apparently by a concentration-dependent manner after Cu, Cr, Cd and Pb exposure, and we selected non-lethal concentrations 0.05 mg/L for Cu, 15 mg/L for Cr, 3 mg/L for Cd and 93.75μg/L for Pb to test the effect on the following biological indicators. Under non-lethal concentration, the four heavy metals have no apparent histological change in adult zebrafish gills. Similar trends in ROS production, MDA level and SOD activity were up-regulated by the four heavy metals, while MDA level responded more sensitive to Pb by time-dependent manner than the other three heavy metals. In addition, mRNA levels related to antioxidant system (SOD1, SOD2 and Nrf2) were up-regulated by non-lethal concentration Cu, Cr, Cd and Pb exposure. MDA level and SOD1 gene have a more delayed response to heavy metals. Genes related to immunotoxicity were increased significantly after heavy metals exposure at non-lethal concentrations. TNF-α and IL-1β gene have similar sensibility to the four heavy metals, while IL-8 gene was more responsive to Cr, Cd and Pb exposure at 48 h groups and IFN-γ gene showed more sensitivity to Cu at 48 h groups than the other heavy metals. In conclusion, the present works have suggested that the IFN-γ gene may applied as early sensitive biomarker to identify Cu-induced toxicity, while MDA content and IL-8 gene may use as early sensitive biomarkers for evaluating the risk of Pb exposure. Moreover, IL-8 and IFN-γ gene were more responsive to heavy

Understanding the Effect of Gas Dynamics in Plasma Gun Performance for Simulating Fusion Wall Response to Disruption Events

Science.gov (United States)

Riedel, Will; Underwood, Thomas; Righetti, Fabio; Cappelli, Mark

2017-10-01

In this work, the suitability of a pulsed coaxial plasma accelerator to simulate the interaction of edge-localized modes with plasma first wall materials is investigated. Experimental measurements derived from a suite of diagnostics are presented that focus on both the properties of the plasma flow and the manner in which such jets couple with material interfaces. Specific emphasis is placed on quantifying the variation in these properties using tungsten tokens exposed to the plasma plume as the gun volume is progressively filled with more neutral gas. These results are mapped to the operational dynamics of the gun via a time-resolved Schlieren cinematic visualization of the density gradient within the flow. Resulting videos indicate the existence of two distinct modes with vastly different characteristic timescales, spatial evolution, and plasma properties. Time resolved quantification of the associated plasma heat flux for both modes, including a range spanning 150 MW m-2 - 10 GW m-2, is presented using both a fast thermocouple gauge and an IR camera. Both diagnostics in conjunction with a heat transfer model provide an accurate description of the energy transfer dynamics and operational characteristics of plasma guns. This work is supported by the U.S. Department of Energy Stewardship Science Academic Program.

Boundary spanning by nurse managers: effects of managers' characteristics and scope of responsibility on teamwork.

Science.gov (United States)

Meyer, Raquel M; O'Brien-Pallas, Linda; Doran, Diane; Streiner, David; Ferguson-Paré, Mary; Duffield, Christine

2014-06-01

Increasing role complexity has intensified the work of managers in supporting healthcare teams. This study examined the influence of front-line managers' characteristics and scope of responsibility on teamwork. Scope of responsibility considers the breadth of the manager's role. A descriptive, correlational design was used to collect cross-sectional survey and administrative data in four acute care hospitals. A convenience sample of 754 staff completed the Relational Coordination Scale as a measure of teamwork that focuses on the quality of communication and relationships. Nurses (73.9%), allied health professionals (14.7%) and unregulated staff (11.7%) worked in 54 clinical areas, clustered under 30 front-line managers. Data were analyzed using hierarchical linear modelling. Leadership practices, clinical support roles and compressed operational hours had positive effects on teamwork. Numbers of non-direct report staff and areas assigned had negative effects on teamwork. Teamwork did not vary by span, managerial experience, worked hours, occupational diversity or proportion of full-time employees. Large, acute care teaching hospitals can enable managers to foster teamwork by enhancing managers' leadership practices, redesigning the flow or reporting structure for non-direct reports, optimizing managerial hours relative to operational hours, allocating clinical support roles, reducing number of areas assigned and, potentially, introducing co-manager models. Copyright © 2014 Longwoods Publishing.

Full-scale horizontal cable-tray tests: Fire-propagation characteristics

International Nuclear Information System (INIS)

Anon.

1991-01-01

At the Fermi National Accelerator Center (Fermilab), as at any high-energy physics laboratory, the experimental program depends on complex arrays of equipment that require years to assemble and place in service. These equipment arrays are typically located in enclosed tunnels or experimental halls and could be destroyed by rapidly propagating, uncontrolled fire. Cable trays, both vertical and horizontal, are an integral and ubiquitous component of these installations. Concurrently, throughout industry and within the professional fire-fighting community, there has been concern over the flammability and fire propagation characteristics of electrical cables in open cable trays. While some information was available concerning fire propagation in vertical cable trays, little was known about fires in horizontal cable trays. In view of the potential for loss of equipment and facilities, not to mention the programmatic impact of a fire, Fermilab initiated a program of full-scale, horizontal cable-tray fire tests to determine the flammability and rate of horizontal fire propagation in cable-tray configurations and cable mixed typical of those existing in underground tunnel enclosures and support buildings as Fermilab. This series of tests addressed the effects of ventilation rates and cable-tray fill, fire-fighting techniques, and the effectiveness and value of automatic sprinklers, smoke detection, and cable-coating fire barriers in detecting, controlling, or extinguishing a cable-tray fire. Detailed descriptions of each fire test, including sketches of cable-tray configuration and contents, instrumentation, ventilation rates, Fermilab Fire Department personnel observations, photographs, and graphs of thermocouple readings are available in a report of these tests prepared by the Fermilab Safety Section

Response of fire detectors to different smokes

International Nuclear Information System (INIS)

Bjoerkman, J.; Keski-Rahkonen, O.

1997-01-01

The purpose of this work is to characterize the behavior of fire alarm systems based on smoke detectors on smoldering fires especially cable fires in nuclear power plants (NPP). Full-scale fire experiments were carried out in a laboratory designed according to the standard EN54-9. The laboratory was instrumented with additional equipment such as thermocouples and flow meters which are not used in standard fire sensitivity tests. This allows the results to be used as experimental data for validation tasks of numerical fire simulation computerized fluid dynamics (CFD)-codes. The ultimate goal of the research is to model theoretically smoldering and flaming cable fires, their smoke production, transfer of smoke to detectors, as well as the response of detectors and fire alarm systems to potential fires. This would allow the use of numerical fire simulation to predict fire hazards in different fire scenarios found important in PSA (probability safety assessment) of NPPs. This report concentrates on explaining full-scale fire experiments in the smoke sensitivity laboratory and experimental results from fire tests of detectors. Validation tasks with CFD-codes will be first carried out 'blind' without any idea about corresponding experimental results. Accordingly, the experimental results cannot be published in this report. (orig.)

Caregiver Responsiveness to the Family Bereavement Program: What predicts responsiveness? What does responsiveness predict?

OpenAIRE

Schoenfelder, Erin N.; Sandler, Irwin N.; Millsap, Roger E.; Wolchik, Sharlene A.; Berkel, Cady; Ayers, Timothy S.

2013-01-01

The study developed a multi-dimensional measure to assess participant responsiveness to a preventive intervention, and applied this measure to study how participant baseline characteristics predict responsiveness and how responsiveness predicts program outcomes. The study was conducted with caregivers who participated in the parenting-focused component of the Family Bereavement Program (FBP), a prevention program for families that have experienced parental death. The sample consisted of 89 ca...

Characteristics and thermal behavior analysis of lithium-ion batteries for application in hybrid locomotives

Science.gov (United States)

Chatterjee, Krishnashis

The locomotive industry accounts for 2.5 % of the total fuel consumption in the US. Thus the necessity for reducing fuel consumption and emissions led to the development of the concept of hybrid locomotive which is dual powered by the diesel engine and electric motors. But the energy dissipated in braking such a locomotive in a year is enough to power over 9100 average US households over the same period of time. Recovering this energy using regenerative braking system and storing it in a electric battery is of great interest among researchers for improving overall efficiency and reducing consumption of fuels. In the present study, LiFePO4 batteries, a type of the state-of-art lithium-ion batteries, have been tested under different environmental and load conditions. Environmental temperatures were varied to analyze their effects on the charging and discharging patterns of the battery by using the CADEX battery analyzer in order to find the temperature range for optimum battery performance. The fluctuations of temperature of the battery surface were monitored along the length of the tests, using Infra-Red imaging and thermocouple probes at different points on the battery surface. Both battery performance characteristics and the variation of the battery surface temperature were also recorded for different load cycles in order to get a comprehensive picture of the heat generation and its effect on the behavior of the battery under different load conditions. Lastly a practical Load Cycle analysis of the battery has been performed which gave a picture of the heat generated by the battery and also the performance characteristics as it is subjected to a practical Load Cycle.

Results and interpretation of noise measurements using in-core self powered neutron detector strings at Unit 2 of the Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Gloeckler, O.; Por, G.; Valko, J.

1986-11-01

In-core neutron noise and fuel assembly outlet temperature noise measurements were performed at Unit 2 of Paks Nuclear Power Plant. Characteristics of the reactor and the noise measuring equipment are briefly described. The in-core Rhodium emitter selfpowered neutron detector strings positioned axially above the other show high coherence and linear phase at low frequencies indicating a marked transport effect, not regularly measured in PWRs. The coherence between horizontally placed neutron detectors is small and the phase is zero. A transport effect of different nature is obtained between neutron detectors (in-core and ex-core) and fuel assembly outlet thermocouples. The observed characteristics depend on reactor and fuel assembly power in a way supporting interpretation in terms of coolant density and void content changes and power feedback effects. During routine analysis vibration of 1.1 Hz appeared as a strong peak in the power spectra. The control assembly that was responsible for the observed behaviour could be localized with high certainty. (author)

Performance of core exit thermocouple for PWR accident management action in vessel top break LOCA simulation experiment at OECD/NEA ROSA project

International Nuclear Information System (INIS)

Suzuki, Mitsuhiro; Takeda, Takeshi; Nakamura, Hideo

2009-01-01

Presented are experiment results of the Large Scale Test Facility (LSTF) conducted at the Japan Atomic Energy Agency (JAEA) with a focus on core exit thermocouple (CET) performance to detect core overheat during a vessel top break loss-of-coolant accident (LOCA) simulation experiment. The CET temperatures are used to start accident management (AM) action to quickly depressurize steam generator (SG) secondary side in case of core temperature excursion. Test 6-1 is first test of the OECD/NEA ROSA Project started in 2005, simulating withdraw of a control rod drive mechanism penetration nozzle at the vessel top head. The break size is equivalent to 1.9% cold leg break. The AM action was initiated when CET temperature rose up to 623K. There was no reflux water fallback onto the CETs during the core heat-up period. The core overheat, however, was detected with a time delay of about 230s. In addition, a large temperature discrepancy was observed between the CETs and the hottest core region. This paper clarifies the reason of time delay and temperature discrepancy between the CETs and heated core during boil-off including three-dimensional steam flows in the core and core exit. The paper discusses applicability of the LSTF CET performance to pressurized water reactor (PWR) conditions and a possibility of alternative indicators for earlier AM action than in Test 6-1 is studied by using symptom-based plant parameters such as a reactor vessel water level detection. (author)

GE post-test analysis of SLSF experiment W-1 through LOPI-4

International Nuclear Information System (INIS)

Gregoire, K.E.; Atcheson, D.B.; Knight, D.D.

1981-07-01

SLSF experiment W-1 was designed to investigate fuel pin-to-coolant heat transfer during various LMFBR flow-coastdown events in the burnup interval from 0.0 atom percent to 0.5 atom percent. In the study reported here, data from in-fuel thermocouples and coolant (wire-wrap) thermocouples were evaluated during steady-state and transient operation from the beginning of the experiment through LOPI-4 (Loss-of-Piping-Integrity Transient Number 4). The objective of the data evaluation was to determine how maximum coolant temperatures during successive LOPI transients were affected by burnup. A second objective was to identify the mechanisms responsible for this burnup effect

Dynamic response characteristics of the high-temperature superconducting maglev system under lateral eccentric distance

Science.gov (United States)

Wang, Bo; Zheng, Jun; Si, Shuaishuai; Qian, Nan; Li, Haitao; Li, Jipeng; Deng, Zigang

2016-07-01

Off-centre operation of high-temperature superconducting (HTS) maglev systems caused by inevitable conditions such as the misregistration of vehicle, crosswind and curve negotiation, may change the distribution of the trapped flux in the HTS bulks and the magnetic interaction between HTS bulks and the PMG. It impacts on the performance of HTS maglev, and more seriously makes the maglev vehicle overturned. Therefore, understanding the performance of the HTS maglev in off-center operation is very important. In this paper, the dynamic response characteristics of a cryostat with twenty-four onboard YBaCuO superconductor bulks were experimentally investigated at different eccentric distances under loads before the initial FC process. Parameters such as vibration accelerations, displacement, natural frequency and dynamic stiffness were acquired and analyzed via the B&K vibration analyzer and laser displacement sensors. Results suggest that the natural frequency and dynamic stiffness of the maglev vehicle would be obviously reduced with the eccentric distance, posing negative effects on the stability of HTS maglev.

Whiplash evokes descending muscle recruitment and sympathetic responses characteristic of startle

Science.gov (United States)

Mang, Daniel WH; Siegmund, Gunter P; Blouin, Jean-Sébastien

2014-01-01

Whiplash injuries are the most common injuries following rear-end collisions. During a rear-end collision, the human muscle response consists of both a postural and a startle response that may exacerbate injury. However, most previous studies only assessed the presence of startle using data collected from the neck muscles and head/neck kinematics. The startle response also evokes a descending pattern of muscle recruitment and changes in autonomic activity. Here we examined the recruitment of axial and appendicular muscles along with autonomic responses to confirm whether these other features of a startle response were present during the first exposure to a whiplash perturbation. Ten subjects experienced a single whiplash perturbation while recording electromyography, electrocardiogram, and electrodermal responses. All subjects exhibited a descending pattern of muscle recruitment, and increasing heart rate and electrodermal responses following the collision. Our results provide further support that the startle response is a component of the response to whiplash collisions. PMID:24932015

Characteristic and analysis of structural elements of corporate social responsibility

Directory of Open Access Journals (Sweden)

J. S. Bilonog

2015-04-01

Full Text Available In this article attention is focused on social responsibility of business and on necessity to estimate its condition in Ukraine. Materials regarding elements and the principles of corporate social responsibility are structured. On this basis unification of quantitative elements of business social responsibility is offered according to which it is possible to carry out the analysis of the non­financial reporting. It is proposed to use not only quantitative techniques of data analysis but also refer to the qualitative ones. As a result of this, the analysis of social reports will be more productive and would minimize subjectivity of the researcher or representatives of the company which are responsible for presenting the information to the general public. The basic principles by which the companies can realize the strategy of corporate social responsibility are considered. Due to the empirical analysis of corporate reports expediency to use specified elements is proved. Reports of the companies in producing and non­productive sector are analyzed in more detail; features of displaying information on corporate social responsibility are defined. The attention to need of carrying out monitoring researches in the sphere of the corporate social reporting is updated.

Spatiotemporal characteristics of retinal response to network-mediated photovoltaic stimulation.

Science.gov (United States)

Ho, Elton; Smith, Richard; Goetz, Georges; Lei, Xin; Galambos, Ludwig; Kamins, Theodore I; Harris, James; Mathieson, Keith; Palanker, Daniel; Sher, Alexander

2018-02-01

Subretinal prostheses aim at restoring sight to patients blinded by photoreceptor degeneration using electrical activation of the surviving inner retinal neurons. Today, such implants deliver visual information with low-frequency stimulation, resulting in discontinuous visual percepts. We measured retinal responses to complex visual stimuli delivered at video rate via a photovoltaic subretinal implant and by visible light. Using a multielectrode array to record from retinal ganglion cells (RGCs) in the healthy and degenerated rat retina ex vivo, we estimated their spatiotemporal properties from the spike-triggered average responses to photovoltaic binary white noise stimulus with 70-μm pixel size at 20-Hz frame rate. The average photovoltaic receptive field size was 194 ± 3 μm (mean ± SE), similar to that of visual responses (221 ± 4 μm), but response latency was significantly shorter with photovoltaic stimulation. Both visual and photovoltaic receptive fields had an opposing center-surround structure. In the healthy retina, ON RGCs had photovoltaic OFF responses, and vice versa. This reversal is consistent with depolarization of photoreceptors by electrical pulses, as opposed to their hyperpolarization under increasing light, although alternative mechanisms cannot be excluded. In degenerate retina, both ON and OFF photovoltaic responses were observed, but in the absence of visual responses, it is not clear what functional RGC types they correspond to. Degenerate retina maintained the antagonistic center-surround organization of receptive fields. These fast and spatially localized network-mediated ON and OFF responses to subretinal stimulation via photovoltaic pixels with local return electrodes raise confidence in the possibility of providing more functional prosthetic vision. NEW & NOTEWORTHY Retinal prostheses currently in clinical use have struggled to deliver visual information at naturalistic frequencies, resulting in discontinuous percepts. We

The characteristics of a pneumatic muscle

Directory of Open Access Journals (Sweden)

Pietrala Dawid

2017-01-01

Full Text Available The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics. It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics. It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics. The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

The characteristics of a pneumatic muscle

Science.gov (United States)

Pietrala, Dawid

The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

Impedance response characteristics of iron oxide interface in the EDTA solutions

International Nuclear Information System (INIS)

Sawa, Tosio; Higuchi, Shigeo; Kataoka, Ichiro; Ito, Hisao.

1986-01-01

The relationship between the dissolution and the surface conditions of Fe 3 O 4 were studied in the various conditions of EDTA solutions by means of the A · C impedance measurement. From the experimental results obtained, surface layer of Fe 3 O 4 electrode can be expressed with electrical equivalent circuit that have capacitance and reaction resistance in the electrical double layer. In the Na 2 SO 4 solution without occuring dissolution, reaction resistance was estimated as 314 kΩ · cm 2 and capacitance was 203 μF/cm 2 . In the EDTA solutions, reaction resistance decreases along with dissolution of Fe 3 O 4 . The factors to make decrease reaction resistance are EDTA concentration, pH and temperature of the solutions. In contrast with this, the factor to increase it is dissolved oxygen in the solutions. The reciprocal value of reaction resistance agrees well with the rate of dissolution. On the other hand, when the electrode potential was maintained under the cathodic polarization in the EDTA solutions, impedances of electrode surface showed the lower value than that in the immersion condition. And apparent resistance came near to 0 at the potential of -2.0 V in all the range of frequency. Fe 3 O 4 electrodes pretreated with the cathodic polarization exhibited the characteristic impedance response that were caused by the change of electrode surface and the deposites such as iron hydroxide. (author)

Investigation into response characteristics of the chitosan gel artificial muscle

Science.gov (United States)

Zhao, Gang; Yang, Junjie; Wang, Yujian; Zhao, Honghao; Fu, Yu; Zhang, Guangli; Yu, Shuqin; Wu, Yuda; Wei, Chengye; Liu, Xuxiong; Wang, Zhijie

2018-01-01

Bionic artificial muscle made from chitosan gel is an emerging type of the ionic electro active polymer with advantages of large deformation, low cost and environmental protection etc, which leads to a research focus and wide application in the fields of bionic engineering and intelligence material recently. In this paper, effects and improvement mechanisms of the direct casting and genipin cross-linking processes on response speed properties of the chitosan gel artificial muscle (CGAM) were mainly studied. Based on in-depth analysis of the CGAM response mechanism, a platform was built for testing the response performance of the CGAM, then its equivalent circuit and mathematical models were also established. Furthermore, control experiments were carried out to test and analyze several performances of the CGAM on response speed, electrical conductivity, mechanical properties and microstructure with different control variables. The experimental results illustrated that the CGAM assembled by direct casting enabled its electric actuating membrane and non-metallic electrode membrane tightly attached together with low contact resistance, which dramatically promoted the electrical conductivity of the CGAM resulting in nearly doubled response speed. Besides, different concentrations of genipin were adopted to cross-link the CGAM actuating membranes, and then it was found that the response speed of the uncross-linked CGAM was fast in the initial stage, but as time increased, it declined rapidly with poor steadiness. While there was no obvious decrease over time on the response speed of the CGAM cross-linked with low genipin concentration. Namely, its stability was getting better and better. In addition, the response speed of the CGAM cross-linked with low concentration of genipin was roughly the same as uncross-linked CGAM, which was quicker than that of high concentration. In this work, its internal mechanisms, feasible assembly technique and green modification method were

Temporal characteristics of gustatory responses in rat parabrachial neurons vary by stimulus and chemosensitive neuron type.

Science.gov (United States)

Geran, Laura; Travers, Susan

2013-01-01

It has been demonstrated that temporal features of spike trains can increase the amount of information available for gustatory processing. However, the nature of these temporal characteristics and their relationship to different taste qualities and neuron types are not well-defined. The present study analyzed the time course of taste responses from parabrachial (PBN) neurons elicited by multiple applications of "sweet" (sucrose), "salty" (NaCl), "sour" (citric acid), and "bitter" (quinine and cycloheximide) stimuli in an acute preparation. Time course varied significantly by taste stimulus and best-stimulus classification. Across neurons, the ensemble code for the three electrolytes was similar initially but quinine diverged from NaCl and acid during the second 500 ms of stimulation and all four qualities became distinct just after 1s. This temporal evolution was reflected in significantly broader tuning during the initial response. Metric space analyses of quality discrimination by individual neurons showed that increases in information (H) afforded by temporal factors was usually explained by differences in rate envelope, which had a greater impact during the initial 2s (22.5% increase in H) compared to the later response (9.5%). Moreover, timing had a differential impact according to cell type, with between-quality discrimination in neurons activated maximally by NaCl or citric acid most affected. Timing was also found to dramatically improve within-quality discrimination (80% increase in H) in neurons that responded optimally to bitter stimuli (B-best). Spikes from B-best neurons were also more likely to occur in bursts. These findings suggest that among PBN taste neurons, time-dependent increases in mutual information can arise from stimulus- and neuron-specific differences in response envelope during the initial dynamic period. A stable rate code predominates in later epochs.

Experimental study on occupant's thermal responses under the non-uniform conditions in vehicle cabin during the heating period

Science.gov (United States)

Zhang, Wencan; Chen, Jiqing; Lan, Fengchong

2014-03-01

The existing investigations on thermal comfort mostly focus on the thermal environment conditions, especially of the air-flow field and the temperature distributions in vehicle cabin. Less attention appears to direct to the thermal comfort or thermal sensation of occupants, even to the relationship between thermal conditions and thermal sensation. In this paper, a series of experiments were designed and conducted for understanding the non-uniform conditions and the occupant's thermal responses in vehicle cabin during the heating period. To accurately assess the transient temperature distribution in cabin in common daily condition, the air temperature at a number of positions is measured in a full size vehicle cabin under natural winter environment in South China by using a discrete thermocouples network. The occupant body is divided into nine segments, the skin temperature at each segment and the occupant's local thermal sensation at the head, body, upper limb and lower limb are monitored continuously. The skin temperature is observed by using a discrete thermocouples network, and the local thermal sensation is evaluated by using a seven-point thermal comfort survey questionnaire proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc(ASHRAE) Standard. The relationship between the skin temperature and the thermal sensation is discussed and regressed by statistics method. The results show that the interior air temperature is highly non-uniform over the vehicle cabin. The locations where the occupants sit have a significant effect on the occupant's thermal responses, including the skin temperature and the thermal sensation. The skin temperature and thermal sensation are quite different between body segments due to the effect of non-uniform conditions, clothing resistance, and the human thermal regulating system. A quantitative relationship between the thermal sensation and the skin temperature at each body segment of occupant in

Real-time synchronous measurement of curing characteristics and polymerization stress in bone cements with a cantilever-beam based instrument

Science.gov (United States)

Palagummi, Sri Vikram; Landis, Forrest A.; Chiang, Martin Y. M.

2018-03-01

An instrumentation capable of simultaneously determining degree of conversion (DC), polymerization stress (PS), and polymerization exotherm (PE) in real time was introduced to self-curing bone cements. This comprises the combination of an in situ high-speed near-infrared spectrometer, a cantilever-beam instrument with compliance-variable feature, and a microprobe thermocouple. Two polymethylmethacrylate-based commercial bone cements, containing essentially the same raw materials but differ in their viscosity for orthopedic applications, were used to demonstrate the applicability of the instrumentation. The results show that for both the cements studied the final DC was marginally different, the final PS was different at the low compliance, the peak of the PE was similar, and their polymerization rates were significantly different. Systematic variation of instrumental compliance for testing reveals differences in the characteristics of PS profiles of both the cements. This emphasizes the importance of instrumental compliance in obtaining an accurate understanding of PS evaluation. Finally, the key advantage for the simultaneous measurements is that these polymerization properties can be correlated directly, thus providing higher measurement confidence and enables a more in-depth understanding of the network formation process.

A new temperature collection system

International Nuclear Information System (INIS)

Kong Wenchuang; Wang Daihua; Zhang Zhijie

2011-01-01

According to the characteristics of explosion field temperature testing, a new temperature collection system based on complex programmable logic device (CPLD), single chip microcontroller (SCM) and static ram (SRAM) is proposed. The system adopts the NANMAC E12 type of thermocouple as the temperature sensor, DS600 temperature sensor for cold temperature compensation, with rapid synchronous collection, trigger and working parameters adjustable characteristics. The system used SCM combined with USB communication interface, easy operation and reliable. (authors)

Generalized characteristic ratios assignment for commensurate fractional order systems with one zero.

Science.gov (United States)

Tabatabaei, Mohammad

2017-07-01

In this paper, a new method for determination of the desired characteristic equation and zero location of commensurate fractional order systems is presented. The concept of the characteristic ratio is extended for zero-including commensurate fractional order systems. The generalized version of characteristic ratios is defined such that the time-scaling property of characteristic ratios is also preserved. The monotonicity of the magnitude frequency response is employed to assign the generalized characteristic ratios for commensurate fractional order transfer functions with one zero. A simple pattern for characteristic ratios is proposed to reach a non-overshooting step response. Then, the proposed pattern is revisited to reach a low overshoot (say for example 2%) step response. Finally, zero-including controllers such as fractional order PI or lag (lead) controllers are designed using generalized characteristic ratios assignment method. Numerical simulations are provided to show the efficiency of the so designed controllers. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Characteristics of Response of Piezoelectric Actuators in Electron Flux Excitation

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Philip C. Hadinata

2003-11-01

Full Text Available In this paper the working parameters of non-contact strain control for piezoelectric ceramics are evaluated. The piezoelectric material functions as an actuator that transforms electrical into mechanical energy, and the electrical input is carried out by electron flux on the positive surface. The sample is exposed to some quasi-static inputs, and its responses are recorded using strain gages. The data shows faster and more stable response in the positive regime, but significantly slower response with drift in the negative regime. An electron collector is introduced on the positive surface to enhance the response in the negative regime. Theoretical analyses of energy transfer and electron movements is discussed, and a string of working conditions for controlling the surface strain of piezoelectric material are given as conclusions.

Low temperature transient response and electroluminescence characteristics of OLEDs based on Alq3

Science.gov (United States)

Yuan, Chao; Guan, Min; Zhang, Yang; Li, Yiyang; Liu, Shuangjie; Zeng, Yiping

2017-08-01

In this work, the organic light-emitting diodes (OLEDs) based on Alq3 are fabricated. In order to make clear the transport mechanism of carriers in organic light-emitting devices at low temperature, detailed electroluminescence transient response and the current-voltage-luminescence (I-V-L) characteristics under different temperatures in those OLEDs are investigated. It founds that the acceleration of brightness increases with increasing temperature is maximum when the temperature is 200 K and it is mainly affected by the electron transport layer (Alq3). The MoO3 injection layer and the electroluminescent layer have great influence on the delay time when the temperature is 200 K. Once the temperature is greater than 250 K, the delay time is mainly affected by the MoO3 injection layer. On the contrary, the fall time is mainly affected by the electroluminescent material. The Vf is the average growth rate of fall time when the temperature increases 1 K which represents the accumulation rate of carriers. The difference between Vf caused by the MoO3 injection layer is 0.52 us/K and caused by the electroluminescent material Ir(ppy)3 is 0.73 us/K.

Site geological and geotechnical studies, determination of soil characteristics and soil response studies

International Nuclear Information System (INIS)

1985-08-01

RFS or Regles Fondamentales de Surete (Basic Safety Rules) applicable to certain types of nuclear facilities lay down requirements with which compliance, for the type of facilities and within the scope of application covered by the RFS, is considered to be equivalent to compliance with technical French regulatory practice. The object of the RFS is to take advantage of standardization in the field of safety, while allowing for technical progress in that field. They are designed to enable the operating utility and contractors to know the rules pertaining to various subjects which are considered to be acceptable by the Service Central de Surete des Installations Nucleaires, or the SCSIN (Central Department for the Safety of Nuclear Facilities). These RFS should make safety analysis easier and lead to better understanding between experts and individuals concerned with the problems of nuclear safety. The SCSIN reserves the right to modify, when considered necessary, any RFS and specify, if need be, the terms under which a modification is deemed retroactive. The purpose of this RFS is to specify the soil characteristics to be determined and the soil response studies to be performed as part of site geological and geotechnical studies

Experimental study on the heat transfer characteristics of a nuclear reactor containment wall cooled by gravitationally falling water

Science.gov (United States)

Pasek, Ari D.; Umar, Efrison; Suwono, Aryadi; Manalu, Reinhard E. E.

2012-06-01

Gravitationally falling water cooling is one of mechanism utilized by a modern nuclear Pressurized Water Reactor (PWR) for its Passive Containment Cooling System (PCCS). Since the cooling is closely related to the safety, water film cooling characteristics of the PCCS should be studied. This paper deals with the experimental study of laminar water film cooling on the containment model wall. The influences of water mass flow rate and wall heat rate on the heat transfer characteristic were studied. This research was started with design and assembly of a containment model equipped with the water cooling system, and calibration of all measurement devices. The containment model is a scaled down model of AP 1000 reactor. Below the containment steam is generated using electrical heaters. The steam heated the containment wall, and then the temperatures of the wall in several positions were measure transiently using thermocouples and data acquisition. The containment was then cooled by falling water sprayed from the top of the containment. The experiments were done for various wall heat rate and cooling water flow rate. The objective of the research is to find the temperature profile along the wall before and after the water cooling applied, prediction of the water film characteristic such as means velocity, thickness and their influence to the heat transfer coefficient. The result of the experiments shows that the wall temperatures significantly drop after being sprayed with water. The thickness of water film increases with increasing water flow rate and remained constant with increasing wall heat rate. The heat transfer coefficient decreases as film mass flow rate increase due to the increases of the film thickness which causes the increasing of the thermal resistance. The heat transfer coefficient increases slightly as the wall heat rate increases. The experimental results were then compared with previous theoretical studied.

Similar simulation study on the characteristics of the electric potential response to coal mining

Science.gov (United States)

Niu, Yue; Li, Zhonghui; Kong, Biao; Wang, Enyuan; Lou, Quan; Qiu, Liming; Kong, Xiangguo; Wang, Jiali; Dong, Mingfu; Li, Baolin

2018-02-01

An electric potential (EP) can be generated during the failure process of coal and rock. In this article, a similar physical model of coal rock was built and the characteristics of the EP responding to the process of coal mining were studied. The results showed that, at the early mining stage, the structure of coal rock strata were stable in the simulation model, the support stress of overlying coal rock strata was low and the maximum subsidence was little, while the EP change was less. With the advancement of the working face, the support stress of the overlying coal rock strata in the mined-out area changed dramatically, the maximum subsidence increased constantly, the deformation and destruction were aggravated, and cracks expanded continuously. Meanwhile, the EP response was significant with fluctuation. When significant macro damage appeared in coal rock strata, the EP signal fluctuation was violent. The overlying coal rock strata were influenced by gravity and mining activity. During the mining process, the crack growth and the friction, together with slip between coal and rock particles, resulted in the response of EP. The change in EP was closely related to the damage state and stress distribution of the coal rock strata. EP monitoring has the advantages of accurate reflection and strong anti-interference in the field. Therefore, with further study, an EP monitoring method could be applied for monitoring and early warning of coal and rock dynamic disaster, and risk evaluation in the future. The strength of the EP and its fluctuation degree could serve as the key discrimination indexes.

Approach to the HTGR core outlet temperature measurements in the United States

International Nuclear Information System (INIS)

Franklin, R.; Rodriguez, C.

1982-06-01

The High Temperature Gas-Cooled Reactor (HTGR) constructed at Fort St. Vrain Colorado (330 MWe) used Geminol thermocouples to measure the primary coolant temperature at the core outlet. The primary coolant (helium) is heated by the graphite core to temperatures in the range of 700 deg. to 750 deg. C. The combination of the high temperature, high flow rate and radiation at the core outlet area makes it difficult to obtain accurate temperature measurements. The Geminol thermocouples installed in the Fort St. Vrain reactor have provided accurate data for several years of power operation without any failures. The indicated temperature of the core outlet thermocouples agrees with a ''traversing'' thermocouple measurement to within +-2 deg. C. The Geminol thermocouple wire was provided by the Driver-Harris Company and is similar to the chromel versus alumel thermocouple. Geminol wire is no longer distributed and on future designs, chromel versus alumel wire will be used. The next large HTGR design, which is being performed with funding support from the United States Department of Energy, will incorporate replaceable thermocouples. The thermocouples used in the Fort St. Vrain reactor were permanently installed and large in diameter (6.35 mm) to insure good reliability. The replaceable thermocouples to be used in the next large reactor will be smaller in diameter (3.18 mm). These replaceable thermocouples will be inserted into the core outlet area through long curved guide tubes that are permanently installed. These guide tubes are as long as 18 meters and must be curved to reach the core outlet regions. Tests were conducted to prove that the thermocouples could be inserted and removed through the long curved guide tubes. (author)

Dynamic characteristics of otolith ocular response during counter rotation about dual yaw axes in mice.

Science.gov (United States)

Shimizu, N; Wood, S; Kushiro, K; Yanai, S; Perachio, A; Makishima, T

2015-01-29

The central vestibular system plays an important role in higher neural functions such as self-motion perception and spatial orientation. Its ability to store head angular velocity is called velocity storage mechanism (VSM), which has been thoroughly investigated across a wide range of species. However, little is known about the mouse VSM, because the mouse lacks typical ocular responses such as optokinetic after nystagmus or a dominant time constant of vestibulo-ocular reflex for which the VSM is critical. Experiments were conducted to examine the otolith-driven eye movements related to the VSM and verify its characteristics in mice. We used a novel approach to generate a similar rotating vector as a traditional off-vertical axis rotation (OVAR) but with a larger resultant gravito-inertial force (>1g) by using counter rotation centrifugation. Similar to results previously described in other animals during OVAR, two components of eye movements were induced, i.e. a sinusoidal modulatory eye movement (modulation component) on which a unidirectional nystagmus (bias component) was superimposed. Each response is considered to derive from different mechanisms; modulations arise predominantly through linear vestibulo-ocular reflex, whereas for the bias, the VSM is responsible. Data indicate that the mouse also has a well-developed vestibular system through otoliths inputs, showing its highly conserved nature across mammalian species. On the other hand, to reach a plateau state of bias, a higher frequency rotation or a larger gravito-inertial force was considered to be necessary than other larger animals. Compared with modulation, the bias had a more variable profile, suggesting an inherent complexity of higher-order neural processes in the brain. Our data provide the basis for further study of the central vestibular system in mice, however, the underlying individual variability should be taken into consideration. Copyright © 2014 IBRO. Published by Elsevier Ltd. All

Real-time algorithm for the measurement of liquid metal coolant flow velocity with correlated thermal signals

International Nuclear Information System (INIS)

Moazzeni, Taleb; Jiang, Yingtao; Ma, Jian; Li, Ning

2009-01-01

One flow meter was developed especially for the environment of high irradiation, pressure, and temperature. The transit time of natural random temperature fluctuation in process, for example nuclear reactor, can be obtained based on the cross-correlation method, which has already been shown that it is capable in situations where no other flow meter can be used. Thereby, the flow rate can be derived in pipe flow if the area of cross-section is known. In practice, the evaluation of the integrals over the measurement time in cross-correlation method will lead errors caused by peak detection from flat cross correlation coefficient distribution or additional peaks. One Auto-Adaptive Impulse Response Function estimation is introduced and significantly narrower peak will be obtained. Fiber optic sensors are advantageous for temperature measurements in the reactor pressure vessels. However, the corrosive coolant (as liquid lead/lead alloy or molten salt coolant) is a barrier of the optic sensor in such application. Thermocouple with grounded stainless steel shielding material would have same life time with structure material in reactor, although thermocouple has relatively slow response. The degradation due to corrosion/erosion will not introduce measurement error or necessary calibration, because only the correlation between signals is taken into consideration during measurements. Experiments conducted in a testing hydraulic facility approved the considerable improvement of accuracy by this new algorithm using thermocouple temperature sensors. (author)

Shock Tube as an Impulsive Application Device

Directory of Open Access Journals (Sweden)

Soumya Ranjan Nanda

2017-01-01

Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

Analytical design of sensors for measuring during terminal phase of atmospheric temperature planetary entry

Science.gov (United States)

Millard, J. P.; Green, M. J.; Sommer, S. C.

1972-01-01

An analytical study was conducted to develop a sensor for measuring the temperature of a planetary atmosphere from an entry vehicle traveling at supersonic speeds and having a detached shock. Such a sensor has been used in the Planetary Atmosphere Experiments Test Probe (PAET) mission and is planned for the Viking-Mars mission. The study specifically considered butt-welded thermocouple sensors stretched between two support posts; however, the factors considered are sufficiently general to apply to other sensors as well. This study included: (1) an investigation of the relation between sensor-measured temperature and free-stream conditions; (2) an evaluation of the effects of extraneous sources of heat; (3) the development of a computer program for evaluating sensor response during entry; and (4) a parametric study of sensor design characteristics.

Designing an accurate system for temperature measurements

Directory of Open Access Journals (Sweden)

Kochan Orest

2017-01-01

Full Text Available The method of compensation of changes in temperature field along the legs of inhomogeneous thermocouple, which measures a temperature of an object, is considered in this paper. This compensation is achieved by stabilization of the temperature field along the thermocouple. Such stabilization does not allow the error due to acquired thermoelectric inhomogeneity to manifest itself. There is also proposed the design of the furnace to stabilize temperature field along the legs of the thermocouple which measures the temperature of an object. This furnace is not integrated with the thermocouple mentioned above, therefore it is possible to replace this thermocouple with a new one when it get its legs considerably inhomogeneous.. There is designed the two loop measuring system with the ability of error correction which can use simultaneously a usual thermocouple as well as a thermocouple with controlled profile of temperature field. The latter can be used as a reference sensor for the former.

Prediction of an excessive response in in vitro fertilization from patient characteristics and ovarian reserve tests and comparison in subgroups: an individual patient data meta-analysis

NARCIS (Netherlands)

Broer, Simone L.; Dólleman, Madeleine; van Disseldorp, Jeroen; Broeze, Kimiko A.; Opmeer, Brent C.; Bossuyt, Patrick M. M.; Eijkemans, Martinus J. C.; Mol, Ben Willem; Broekmans, Frank J. M.; Broer, S. L.; Dólleman, M.; van Disseldorp, J.; Eijkemans, M. J. C.; Broekmans, F. J. M.; Aflatoonian, A.; Anderson, R. A.; Ashrafi, M.; Bancsi, L.; Caroppo, E.; Copperman, A. B.; Ebner, T.; Eldar-Geva, T.; Erdem, M.; Freour, T.; Gnoth, C.; Greenblatt, E. M.; Jayaprakasan, K.; Raine-Fenning, N.; Klinkert, E.; Kwee, J.; La Marca, A.; Lambalk, C. B.; McIlveen, M.; Mohiyiddeen, L.; Merce, L. T.; Muttukrishna, S.; Nardo, L. G.; Nelson, S. M.; Ng, H. Y.; Popovic-Todorovic, B.; Smeenk, J. M. J.; Tomás, C.; van der Linden, P. J. Q.; van Rooij, I. A.; Vladimirov, I. K.

2013-01-01

To evaluate whether ovarian reserve tests (ORTs) add prognostic value to patient characteristics, such as female age, in the prediction of excessive response to ovarian hyperstimulation in patients undergoing IVF, and whether their performance differs across clinical subgroups. Authors of studies

Characteristics of near-field earthquake ground motion

International Nuclear Information System (INIS)

Kim, H. K.; Choi, I. G.; Jeon, Y. S.; Seo, J. M.

2002-01-01

The near-field ground motions exhibit special response characteristics that are different from those of ordinary ground motions in the velocity and displacement response. This study first examines the characteristics of near-field ground motion depending on fault directivity and fault normal and parallel component. And the response spectra of the near field ground motion are statistically processed, and are compared with the Regulatory Guide 1.60 spectrum that is present design spectrum of the nuclear power plant. The response spectrum of the near filed ground motions shows large spectral velocity and displacement in the low frequency range. The spectral accelerations of near field ground motion are greatly amplified in the high frequency range for the rock site motions, and in the low frequency range for the soil site motions. As a result, the near field ground motion effects should be considered in the seismic design and seismic safety evaluation of the nuclear power plant structures and equipment

An Exploratory Analysis of Sound Field Characteristics using the Impulse Response in a Car Cabin

Directory of Open Access Journals (Sweden)

Yoshiharu Soeta

2018-03-01

Full Text Available Sound environments in cars are becoming quieter and receiving attention because of the prevalence of low-noise engines such as hybrid and electric engines and the manifestation of automated driving. Although the car cabin has potential as a listening space, its acoustic quality has not been examined in detail. The present study investigated sound field characteristics in the car cabin using acoustic parameters obtained by impulse response analysis. In particular, effects of the passenger position, open windows and the use of an air conditioner on acoustic parameters were investigated. The passenger position affected the sound strength at low frequencies. Rear seats, except for the rear central seat, had lower interaural correlation than the front seats, suggesting that rear seats have more diffused sound fields. The opening of windows and use of air conditioners attenuated the ratio of early- and late-arriving energy at high frequencies, suggesting a loss of clarity for music.

Performance characteristics and physiological response of broiler chickens at finisher stage to oral supplementation with fluted pumpkin, Telfairia occidentalis leaf extract

OpenAIRE

Olufemi ALABI; Mathew AYOOLA; Oyebola AKINOSO

2017-01-01

The performance characteristics and physiological response of broiler chickens to oral supplementation with Telfairia occidentalis leaf extract (TOLE) at finisher stage were investigated. One hundred and twenty unsexed broilers of Arbor Acre strain at 28-day-old were randomly divided into four treatment groups of oral supplementation each with three replicates. The treatment groups are: T1=Water (control), T2=Vitalyte, T3=15% TOLE, and T4=30% TOLE. The experiment lasted for 70 days, during wh...

Some characteristics of a miniature neutron spectrometer

International Nuclear Information System (INIS)

Sekimoto, H.; Oishi, K.; Hojo, K.; Hojo, T.

1984-01-01

Some characteristics of an NE213 miniature spherical spectrometer for in-assembly fast-neutron spectrometry were measured. As the bubbling time changed, the pulse-height did not change appreciably, but the n-γ discrimination characteristics changed considerably. As the count rate changed, the pulse-height did not change appreciably, and the change of the n-γ discrimination characteristics was acceptable. The neutron response function was measured to be almost isotropic except for the backward direction. (orig.)

Effects of Control-Response Characteristics on the Capability of Helicopter for Use as a Gun Platform

Science.gov (United States)

Pegg, Robert J.; Connor, Andrew B.

1960-01-01

An investigation with a variable-stability helicopter was undertaken to ascertain the steadiness and ability to "hold on" to the target of a helicopter employed as a gun platform. Simulated tasks were per formed under differing flight conditions with the control-response characteristics of the helicopter varied for each task. The simulated gun-platform mission included: Variations of headings with respect to wind, constant altitude and "swing around" to a wind heading of 0 deg, and increases in altitude while performing a swing around to a wind heading of 0 deg. The results showed that increases in control power and damping increased pilot ability to hold on to the target with fewer yawing oscillations and in a shorter time. The results also indicated that wind direction must be considered in accuracy assessment. Greatest accuracy throughout these tests was achieved by aiming upwind.

Multi-response optimization of surface integrity characteristics of EDM process using grey-fuzzy logic-based hybrid approach

Directory of Open Access Journals (Sweden)

Shailesh Dewangan

2015-09-01

Full Text Available Surface integrity remains one of the major areas of concern in electric discharge machining (EDM. During the current study, grey-fuzzy logic-based hybrid optimization technique is utilized to determine the optimal settings of EDM process parameters with an aim to improve surface integrity aspects after EDM of AISI P20 tool steel. The experiment is designed using response surface methodology (RSM considering discharge current (Ip, pulse-on time (Ton, tool-work time (Tw and tool-lift time (Tup as process parameters. Various surface integrity characteristics such as white layer thickness (WLT, surface crack density (SCD and surface roughness (SR are considered during the current research work. Grey relational analysis (GRA combined with fuzzy-logic is used to determine grey fuzzy reasoning grade (GFRG. The optimal solution based on this analysis is found to be Ip = 1 A, Ton = 10 μs, Tw = 0.2 s, and Tup = 0.0 s. Analysis of variance (ANOVA results clearly indicate that Ton is the most contributing parameter followed by Ip, for multiple performance characteristics of surface integrity.

A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics

Science.gov (United States)

Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason

2013-01-01

This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.

Modularization and Response Curve Engineering of a Naringenin-Responsive Transcriptional Biosensor.

Science.gov (United States)

De Paepe, Brecht; Maertens, Jo; Vanholme, Bartel; De Mey, Marjan

2018-05-18

To monitor the intra- and extracellular environment of micro-organisms and to adapt their metabolic processes accordingly, scientists are reprogramming nature's myriad of transcriptional regulatory systems into transcriptional biosensors, which are able to detect small molecules and, in response, express specific output signals of choice. However, the naturally occurring response curve, the key characteristic of biosensor circuits, is typically not in line with the requirements for real-life biosensor applications. In this contribution, a natural LysR-type naringenin-responsive biosensor circuit is developed and characterized with Escherichia coli as host organism. Subsequently, this biosensor is dissected into a clearly defined detector and effector module without loss of functionality, and the influence of the expression levels of both modules on the biosensor response characteristics is investigated. Two collections of ten unique synthetic biosensors each are generated. Each collection demonstrates a unique diversity of response curve characteristics spanning a 128-fold change in dynamic and 2.5-fold change in operational ranges and 3-fold change in levels of Noise, fit for a wide range of applications, such as adaptive laboratory evolution, dynamic pathway control and high-throughput screening methods. The established biosensor engineering concepts, and the developed biosensor collections themselves, are of use for the future development and customization of biosensors in general, for the multitude of biosensor applications and as a compelling alternative for the commonly used LacI-, TetR- and AraC-based inducible circuits.

Dynamic characteristics of laser Doppler flowmetry signals obtained in response to a local and progressive pressure applied on diabetic and healthy subjects

Science.gov (United States)

Humeau, Anne; Koitka, Audrey; Abraham, Pierre; Saumet, Jean-Louis; L'Huillier, Jean-Pierre

2004-09-01

In the biomedical field, the laser Doppler flowmetry (LDF) technique is a non-invasive method to monitor skin perfusion. On the skin of healthy humans, LDF signals present a significant transient increase in response to a local and progressive pressure application. This vasodilatory reflex response may have important implications for cutaneous pathologies involved in various neurological diseases and in the pathophysiology of decubitus ulcers. The present work analyses the dynamic characteristics of these signals on young type 1 diabetic patients, and on healthy age-matched subjects. To obtain accurate dynamic characteristic values, a de-noising wavelet-based algorithm is first applied to LDF signals. All the de-noised signals are then normalised to the same value. The blood flow peak and the time to reach this peak are then calculated on each computed signal. The results show that a large vasodilation is present on signals of healthy subjects. The mean peak occurs at a pressure of 3.2 kPa approximately. However, a vasodilation of limited amplitude appears on type 1 diabetic patients. The maximum value is visualised, on the average, when the pressure is 1.1 kPa. The inability for diabetic patients to increase largely their cutaneous blood flow may bring explanations to foot ulcers.

Biocompatibility, Inflammatory Response, and Recannalization Characteristics of Nonradioactive Resin Microspheres: Histological Findings

International Nuclear Information System (INIS)

Bilbao, Jose I.; Martino, Alba de; Luis, Esther de; Diaz-Dorronsoro, Lourdes; Alonso-Burgos, Alberto; Martinez de la Cuesta, Antonio; Sangro, Bruno; Garcia de Jalon, Jose A.

2009-01-01

Intra-arterial radiotherapy with yttrium-90 microspheres (radioembolization) is a therapeutic procedure exclusively applied to the liver that allows the direct delivery of high-dose radiation to liver tumors, by means of endovascular catheters, selectively placed within the tumor vasculature. The aim of the study was to describe the distribution of spheres within the precapillaries, inflammatory response, and recannalization characteristics after embolization with nonradioactive resin microspheres in the kidney and liver. We performed a partial embolization of the liver and kidney vessels in nine white pigs. The left renal and left hepatic arteries were catheterized and filled with nonradioactive resin microspheres. Embolization was defined as the initiation of near-stasis of blood flow, rather than total occlusion of the vessels. The hepatic circulation was not isolated so that the effects of reflux of microspheres into stomach could be observed. Animals were sacrificed at 48 h, 4 weeks, and 8 weeks, and tissue samples from the kidney, liver, lung, and stomach evaluated. Microscopic evaluation revealed clusters of 10-30 microspheres (15-30 μm in diameter) in the small vessels of the kidney (the arciform arteries, vasa recti, and glomerular afferent vessels) and liver. Aggregates were associated with focal ischemia and mild vascular wall damage. Occlusion of the small vessels was associated with a mild perivascular inflammatory reaction. After filling of the left hepatic artery with microspheres, there was some evidence of arteriovenous shunting into the lungs, and one case of cholecystitis and one case of marked gastritis and ulceration at the site of arterial occlusion due to the presence of clusters of microspheres. Beyond 48 h, microspheres were progressively integrated into the vascular wall by phagocytosis and the lumen recannalized. Eight-week evaluation found that the perivascular inflammatory reaction was mild. Liver cell damage, bile duct injury, and

Identification of PM{sub 10} characteristics involved in cellular responses in human bronchial epithelial cells (Beas-2B)

Energy Technology Data Exchange (ETDEWEB)

Van Den Heuvel, Rosette, E-mail: rosette.vandenheuvel@vito.be [Flemish Institute for Technological Research (VITO), Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); Den Hond, Elly, E-mail: elly.denhond@wiv-isp.be [Flemish Institute for Technological Research (VITO), Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); Govarts, Eva, E-mail: eva.govarts@vito.be [Flemish Institute for Technological Research (VITO), Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); Colles, Ann, E-mail: ann.colles@vito.be [Flemish Institute for Technological Research (VITO), Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); Koppen, Gudrun, E-mail: gudrun.koppen@vito.be [Flemish Institute for Technological Research (VITO), Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); Staelens, Jeroen, E-mail: j.staelens@vmm.be [Flanders Environment Agency (VMM), Unit Air, Kronenburgstraat 45, 2000 Antwerp (Belgium); Mampaey, Maja, E-mail: maja.mampaey@lne.vlaanderen.be [LNE (Environment, Nature and Energy Department), Flemish Government, Koning Albert II-laan 20, 1000 Brussels (Belgium); Janssen, Nicole, E-mail: nicole.janssen@rivm.nl [National Institute for Public Health and the Environment (RIVM), P.O. Box, 2720 BA, Bilthoven (Netherlands); Schoeters, Greet, E-mail: greet.schoeters@vito.be [Flemish Institute for Technological Research (VITO), Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); University of Antwerp, Department of Biomedical Sciences, 2000 Antwerp (Belgium)

2016-08-15

single and multiple regression analyses. The reduction in cell viability was significantly correlated with BC, Cd and Pb. The induction of IL-8 in Beas-2B cells was significantly associated with Cu, Ni and Zn and endotoxin. Endotoxin levels explained 33% of the variance in IL-8 induction. A significant interaction between ambient temperature and endotoxin on the pro-inflammatory activity was seen. No association was found between OP and the cellular responses. This study supports the hypothesis that, on an equal mass basis, PM{sub 10} induced biological effects differ due to differences in PM{sub 10} characteristics. Metals (Cd, Cu, Ni and Zn), BC, and endotoxin were among the main determinants for the observed biological responses. - Highlights: • On an equal mass basis, PM{sub 10} sampled at an urban, rural and industrial site induced different cellular effects in Beas-2B. • Endotoxin levels and oxidative potential (OP) were analysed in the PM{sub 10} samples. • Black carbon, cadmium and lead were correlated with decreased cell viability. • Endotoxin levels explained the majority of the variance in il-8 induction. • Oxidatively damaged DNA was observed in all the samples.

An in situ spatially resolved analytical technique to simultaneously probe gas phase reactions and temperature within the packed bed of a plug flow reactor.

Science.gov (United States)

Touitou, Jamal; Burch, Robbie; Hardacre, Christopher; McManus, Colin; Morgan, Kevin; Sá, Jacinto; Goguet, Alexandre

2013-05-21

This paper reports the detailed description and validation of a fully automated, computer controlled analytical method to spatially probe the gas composition and thermal characteristics in packed bed systems. As an exemplar, we have examined a heterogeneously catalysed gas phase reaction within the bed of a powdered oxide supported metal catalyst. The design of the gas sampling and the temperature recording systems are disclosed. A stationary capillary with holes drilled in its wall and a moveable reactor coupled with a mass spectrometer are used to enable sampling and analysis. This method has been designed to limit the invasiveness of the probe on the reactor by using the smallest combination of thermocouple and capillary which can be employed practically. An 80 μm (O.D.) thermocouple has been inserted in a 250 μm (O.D.) capillary. The thermocouple is aligned with the sampling holes to enable both the gas composition and temperature profiles to be simultaneously measured at equivalent spatially resolved positions. This analysis technique has been validated by studying CO oxidation over a 1% Pt/Al2O3 catalyst and the spatial resolution profiles of chemical species concentrations and temperature as a function of the axial position within the catalyst bed are reported.

Evaluation of temperature rise in a tissue mimicking material during HIFU exposure

International Nuclear Information System (INIS)

Maruvada, S; Liu, Y; Herman, B A; Harris, G R

2011-01-01

In pre-clinical testing it is essential to characterize clinical high intensity focused ultrasound (HIFU) devices using tissue-mimicking materials (TMMs) with well known characteristics, including temperature rise and cavitation properties. The purpose of this study was to monitor cavitation behavior and correlate its effect with temperature rise in a HIFU TMM containing an embedded thermocouple. A 75-μm fine wire thermocouple was embedded in a hydrogel-based TMM previously developed for HIFU. HIFU at 1.1 and 3.3 MHz was focused at the thermocouple junction. Focal pressures from 1-11 MPa were applied and the temperature profiles were recorded. Three hydrophones were used to monitor cavitation activity during sonication. A hydrophone confocal with the HIFU transducer and a cylindrical hydrophone lateral to the HIFU beam were used as passive cavitation detectors for spectral analysis of signals, and a needle hydrophone placed beyond the HIFU focus was used to record changes in the pressure amplitude due to blockage by bubbles at or near the focus. B-mode imaging scans were employed to visualize bubble presence during sonication. In a separate measurement, schlieren imaging was used to monitor the change in field distribution behind the TMM. All hydrophone methods correlated well with cavitation in the TMM.

Evaluation of temperature rise in a tissue mimicking material during HIFU exposure

Energy Technology Data Exchange (ETDEWEB)

Maruvada, S; Liu, Y; Herman, B A; Harris, G R, E-mail: subha.maruvada@fda.hhs.gov [Food and Drug Administration, Center for Devices and Radiological Health, 10903 New Hampshire Ave., Bldg., Silver Spring, MD 20993 (United States)

2011-02-01

In pre-clinical testing it is essential to characterize clinical high intensity focused ultrasound (HIFU) devices using tissue-mimicking materials (TMMs) with well known characteristics, including temperature rise and cavitation properties. The purpose of this study was to monitor cavitation behavior and correlate its effect with temperature rise in a HIFU TMM containing an embedded thermocouple. A 75-{mu}m fine wire thermocouple was embedded in a hydrogel-based TMM previously developed for HIFU. HIFU at 1.1 and 3.3 MHz was focused at the thermocouple junction. Focal pressures from 1-11 MPa were applied and the temperature profiles were recorded. Three hydrophones were used to monitor cavitation activity during sonication. A hydrophone confocal with the HIFU transducer and a cylindrical hydrophone lateral to the HIFU beam were used as passive cavitation detectors for spectral analysis of signals, and a needle hydrophone placed beyond the HIFU focus was used to record changes in the pressure amplitude due to blockage by bubbles at or near the focus. B-mode imaging scans were employed to visualize bubble presence during sonication. In a separate measurement, schlieren imaging was used to monitor the change in field distribution behind the TMM. All hydrophone methods correlated well with cavitation in the TMM.

Identification of characteristics which influence repository design domal salt, Task 1. Final report

International Nuclear Information System (INIS)

Rawlings, G.; Antonnen, G.; Chamness, M.

1984-04-01

The purpose of the complete project is to provide NRC with technical assistance to enable the focused, adequate review by NRC of the aspects related to design and construction of an underground test facility and final geologic repository as presented by the Department of Energy (DOE). The study presented in this report covers the identification of characteristics which influence design and construction of a geologic repository in domal salt. This report has identified five key issues, i.e., constructibility, thermal response, mechanical response, hydrologic response, and geochemical response. This report involves both short-term (up to closure) and long-term (post closure) effects. The characteristics of domal salt and its environment are described under the headings of stratigraphic/structural, tectonic, mechanical, thermal and hydrologic. Characteristics are separated into parameters (quantified and measured) and factors (qualitative). The characteristics are then subjectively ranked by their influence on the key issues. This takes into account the availability and suitability of conservative design/construction techniques, uncertainty in model and model sensitivity to the characteristic

Elite Youth Soccer Players' Physiological Responses, Time-Motion Characteristics, and Game Performance in 4 vs. 4 Small-Sided Games: The Influence of Coach Feedback.

Science.gov (United States)

Brandes, Mirko; Elvers, Sebastian

2017-10-01

The purpose of this study was to determine the impact of mild vs. strongly pushed coach feedback on the physiological response, ratio of perceived exertion (RPE), and time-motion characteristics in soccer training with small-sided games (SSGs). Sixteen elite youth soccer players (aged 17.2 ± 0.7 years, V[Combining Dot Above]O2max 62.1 ± 3.8 ml·kg·min) played two 4 vs. 4 small-sided games each. In random order, the coach provided a mild, unobtrusive, or a strongly pushed feedback throughout the game. Physiological measurements included heart rate expressed in mean values and intensity zones, blood lactate concentration, and RPE. The distance traveled, number of sprints, and work:rest ratio were captured by global positioning systems at 5 Hz. Game performance, such as volume of play and efficacy index, was estimated using the Team Sports Assessment Procedure. No differences were found for the physiological response and time-motion characteristics, but effect sizes demonstrated an increase in RPE (+0.4, p = 0.27) and a decrease in game performance (e.g., volume of play, -2.5, p = 0.08) under pushed feedback. Although a pushed feedback raises RPE, it negatively affected the players' game performance, without necessarily provoking higher physiological responses. These results should help coaches to understand that modifying the type of feedback provided during SSG does not impact the physiological response if SSG are already played with high intensity but that the feedback affects RPE and game performance. To keep a better game performance, soccer coaches are encouraged to provide smooth feedback during SSG.

Laser-Driven Calorimetry Measurements of Petroleum and Biodiesel Fuels.

Science.gov (United States)

Presser, Cary; Nazarian, Ashot; Millo, Amit

2018-02-01

Thermochemical characteristics were determined for several National Institute of Standards and Technology standard-reference-material petroleum and biodiesel fuels, using a novel laser-heating calorimetry technique. Measurements focused on the sample thermal behavior, specific heat release rate, and total specific heat release. The experimental apparatus consists of a copper sphere-shaped reactor mounted within a chamber, along with laser-beam-steering optical components, gas-supply manifold, and a computer-controlled data-acquisition system. At the center of the reactor, liquid sample is injected onto a copper pan substrate that rests and is in contact with a fine-wire thermocouple. A second thermocouple is in contact with the inner reactor sphere surface. The reactor is heated from opposing sides by a continuous-wave, near-infrared laser to achieve nearly uniform sample temperature. The change in temperature with time (thermogram) is recorded for both thermocouples, and compared to a baseline thermogram (without liquid in the pan). The thermograms are then processed (using an equation for thermal energy conservation) for the thermochemical information of interest. The results indicated that the energy reaching the pan is dominated by radiative heat transfer processes, while the dominant thermal process for the reactor sphere is the stored (internal) thermal energy within the sphere material. Sufficient laser power is necessary to detect the fuel thermal-related characteristics, and the required power can differ from one fuel to another. With sufficient laser power, one can detect the preferential vaporization of the lighter and heavier fuel fractions. The total specific heat release obtained for the different conventional and biodiesel fuels used in this investigation were similar to the expected values available in the literature.

Phase characteristics of earthquake accelerogram and its application

International Nuclear Information System (INIS)

Ohsaki, Y.; Iwasaki, R.; Ohkawa, I.; Masao, T.

1979-01-01

As the input earthquake motion for seismic design of nuclear power plant structures and equipments, an artificial time history compatible with smoothed design response spectrum is frequently used. This paper deals with a wave generation technique based on phase characteristics in earthquake accelerograms as an alternate of envelope time function. The concept of 'phase differences' distribution' is defined to represent phase characteristics of earthquake motion. The procedure proposed in this paper consists of following steps; (1) Specify a design response spectrum and derive a corresponding initial modal amplitude. (2) Determine a phase differences' distribution corresponding to an envelope function, the shape of which is dependent on magnitude and epicentral distance of an earthquake. (3) Derive the phase angles at all modal frequencies from the phase differences' distribution. (4) Generate a time history by inverse Fourier transeform on the basis of the amplitudes and the phase angles thus determined. (5) Calculate the response spectrum. (6) Compare the specified and calculated response spectra, and correct the amplitude at each frequency so that the response spectrum will be consistent with the specified. (7) Repeat the steps 4 through 6, until the specified and calculated response spectra become consistent with sufficient accuracy. (orig.)

Studies on boiling heat transfer on a hemispherical downward heating surface supposing IVR-AM

International Nuclear Information System (INIS)

Yoshida, Kenji; Matsumoto, Hiroyuki; Matsumoto, Tadayoshi; Kataoka, Isao

2006-01-01

The scale-down experiments supposing the IVR-AM were made on the pool boiling heat transfer from hemispherical downward facing heating surface. The boiling phenomena were realized by flooding the heated hemispherical vessel into the sub-cooled water or saturated water under the atmospheric pressure. The hemispherical vessel supposing the scale-down pressure vessel was made of SUS304 stainless steel. Molten lead, which was preheated up to about 500 degrees Celsius, was put into the vessel and used as the heat source. The vessel was cooled down by flooding into the water to realize the quenching process. The direct observation by using the digital video camera was performed and made clear the special characteristics of boiling phenomena such as the film boiling, the transition boiling and the nucleate boiling taking place in order during the cooling process. The measurement for the wall superheat and heat flux by using thermocouples was also carried out to make clear the boiling heat transfer characteristics during the cooling process. Fifteen thermocouples are inserted in the wall of the hemispherical bowl to measure the temperature distributions and heat flux in the hemispherical bowl. (author)

Temperature measurements inside nuclear reactor cores

International Nuclear Information System (INIS)

Tarassenko, Serge

1969-11-01

Non negligible errors may happen in nuclear reactor temperature measurements using magnesium oxide insulated and stainless steel sheathed micro-wire thermocouples, when these thermometric lines are placed under operational conditions typical of electrical power stations. The present work shows that this error is principally due to electrical hysteresis and polarization phenomena in the insulator subjected to the strong fields generated by common-mode voltages. These phenomena favour the unsymmetrical common-mode current flow and thus lead to the differential-mode voltage generation which is superposing on the thermoelectric hot junction potential. A calculation and an experimental approach make possible the importance of the magnesium oxide insulating characteristics, the hot junction insulation, the choice of the main circuits in the data processing equipment as well as the galvanic isolation performances and the common-mode rejection features of all the measurement circuits. A justification is thereby given for the severe conditions imposed for the acceptance of thermoelectric materials; some particular precautions to be taken are described, as well as the high performance characteristics which have to be taken into account in choosing measurement systems linked to thermometric circuits with sheathed micro-wire thermocouples. (author) [fr

Low temperature combustion of organic coal-water fuel droplets containing petrochemicals while soaring in a combustion chamber model

Directory of Open Access Journals (Sweden)

Valiullin Timur R.

2017-01-01

Full Text Available The paper examines the integral characteristics (minimum temperature, ignition delay times of stable combustion initiation of organic coal-water fuel droplets (initial radius is 0.3-1.5 mm in the oxidizer flow (the temperature and velocity varied in ranges 500-900 K, 0.5-3 m/s. The main components of organic coal-water fuel were: brown coal particles, filter-cakes obtained in coal processing, waste engine, and turbine oils. The different modes of soaring and ignition of organic coal-water fuel have been established. The conditions have been set under which it is possible to implement the sustainable soaring and ignition of organic coal-water fuel droplets. We have compared the ignition characteristics with those defined in the traditional approach (based on placing the droplets on a low-inertia thermocouple junction into the combustion chamber. The paper shows the scale of the influence of heat sink over the thermocouple junction on ignition inertia. An original technique for releasing organic coal-water fuel droplets to the combustion chamber was proposed and tested. The limitations of this technique and the prospects of experimental results for the optimization of energy equipment operation were also formulated.

Enhancing the Accuracy of Advanced High Temperature Mechanical Testing through Thermography

Directory of Open Access Journals (Sweden)

Jonathan Jones

2018-03-01

Full Text Available This paper describes the advantages and enhanced accuracy thermography provides to high temperature mechanical testing. This technique is not only used to monitor, but also to control test specimen temperatures where the infra-red technique enables accurate non-invasive control of rapid thermal cycling for non-metallic materials. Isothermal and dynamic waveforms are employed over a 200–800 °C temperature range to pre-oxidised and coated specimens to assess the capability of the technique. This application shows thermography to be accurate to within ±2 °C of thermocouples, a standardised measurement technique. This work demonstrates the superior visibility of test temperatures previously unobtainable by conventional thermocouples or even more modern pyrometers that thermography can deliver. As a result, the speed and accuracy of thermal profiling, thermal gradient measurements and cold/hot spot identification using the technique has increased significantly to the point where temperature can now be controlled by averaging over a specified area. The increased visibility of specimen temperatures has revealed additional unknown effects such as thermocouple shadowing, preferential crack tip heating within an induction coil, and, fundamental response time of individual measurement techniques which are investigated further.

LOFT fuel rod surface temperature measurement testing

International Nuclear Information System (INIS)

Eaton, A.M.; Tolman, E.L.; Solbrig, C.W.

1978-01-01

Testing of the LOFT fuel rod cladding surface thermocouples has been performed to evaluate how accurately the LOFT thermocouples measure the cladding surface temperature during a loss-of-coolant accident (LOCA) sequence and what effect, if any, the thermocouple would have on core performance. Extensive testing has been done to characterize the thermocouple design. Thermal cycling and corrosion testing of the thermocouple weld design have provided an expected lifetime of 6000 hours when exposed to reactor coolant conditions of 620 K and 15.9 MPa and to sixteen thermal cycles with an initial temperature of 480 K and peak temperatures ranging from 870 to 1200K. Departure from nucleate boiling (DNB) tests have indicated a DNB penalty (5 to 28% lower) during steady state operation and negligible effects during LOCA blowdown caused by the LOFT fuel rod surface thermocouple arrangement. Experience with the thermocouple design in Power Burst Facility (PBF) and LOFT nonnuclear blowdown testing has been quite satisfactory. Tests discussed here were conducted using both stainless steel and zircaloy-clad electrically heated rod in the LOFT Test Support Facility (LTSF) blowdown simulation loop

Dynamic Characteristics of Steam Generator Tubes with Defect due to Wear

Energy Technology Data Exchange (ETDEWEB)

Park, Sangjin; Rhee, Huinam [Sunchon National Univ., Sunchon (Korea, Republic of); Yoon, Doo Byung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

These defects may affect the dynamic characteristics of tubes, and therefore, the vibrational behavior of the tube due to flow-induced loads can be varied. Change in the vibrational response of a tube may result in different wear characteristics from the design condition, which must be checked for both safety and economic point of view. This paper deals with the study on the effect of wears or cracks on the dynamic characteristics of steam generator tubes using finite element analysis. In this paper the effect of defects on the surface due to wear on the variation of dynamic characteristics of steam generator tubes was studied using the finite element analysis. The changes of natural frequencies and mode shapes can directly affect the flow-induced vibration response characteristics, therefore, they must be evaluated appropriately. The results in this study can be a good basis to estimate the FIV characteristics of the steam generator tubes having defects such as wear or crack.

Assessment of Patellar Tendon Reflex Responses Using Second-Order System Characteristics

Directory of Open Access Journals (Sweden)

Brett D. Steineman

2016-01-01

Full Text Available Deep tendon reflex tests, such as the patellar tendon reflex (PTR, are widely accepted as simple examinations for detecting neurological disorders. Despite common acceptance, the grading scales remain subjective, creating an opportunity for quantitative measures to improve the reliability and efficacy of these tests. Previous studies have demonstrated the usefulness of quantified measurement variables; however, little work has been done to correlate experimental data with theoretical models using entire PTR responses. In the present study, it is hypothesized that PTR responses may be described by the exponential decay rate and damped natural frequency of a theoretical second-order system. Kinematic data was recorded from both knees of 45 subjects using a motion capture system and correlation analysis found that the mean R2 value was 0.99. Exponential decay rate and damped natural frequency ranges determined from the sample population were −5.61 to −1.42 and 11.73 rad/s to 14.96 rad/s, respectively. This study confirmed that PTR responses strongly correlate to a second-order system and that exponential decay rate and undamped natural frequency are novel measurement variables to accurately measure PTR responses. Therefore, further investigation of these measurement variables and their usefulness in grading PTR responses is warranted.

On-line testing of response time and calibration of temperature and pressure sensors in nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.

1995-01-01

Periodic calibrations and response time measurements are necessary for temperature and pressure sensors in the safety systems of nuclear power plants. Conventional measurement methods require the test to be performed at the sensor location or involve removing the sensor from the process and performing the tests in a laboratory or on the bench. The conventional methods are time consuming and have the potential of causing wear and tear on the equipment, can expose the test personnel to radiation and other harsh environments, and increase the length of the plant outage. Also, the conventional methods do not account for the installation effects which may have an influence on sensor performance. On-line testing methods alleviate these problems by providing remote sensor response time and calibration capabilities. For temperature sensors such as Resistance Temperature Detectors (RTDs) and thermocouples, an on-line test method called the Loop Current Step Response (LCSR) technique has been developed, and for pressure transmitters, an on-line method called noise analysis which was available for reactor diagnostics was validated for response time testing applications. Both the LCSR and noise analysis tests are performed periodically in U.S. nuclear power plants to meet the plant technical specification requirements for response time testing of safety-related sensors. Automated testing of the calibration of both temperature and pressure sensors can be accomplished through an on-line monitoring system installed in the plant. The system monitors the DC output of the sensors over the fuel cycle to determine if any calibration drift has occurred. Changes in calibration can be detected using signal averaging and intercomparison methods and analytical redundancy techniques. (author)

The Effects of Thermal Barrier Coating, Common-Rail Injection, and Reduced Compression Ratio on the Efficiency of Single-Cylinder Diesel Engines

Science.gov (United States)

2010-05-12

Omega Thermocouple ................................................................................................ 61 Figure 29: Omega Monogram Ten...Inter-Loc V Digital Multi-Loop Controller 61 Figure 28: Omega Thermocouple Figure 29: Omega Monogram Ten-Channel...instrument will be used. In this study the thermocouple voltage was converted to a temperature reading by a converter. A Monogram ten-channel

Teachers' Responses to Bullying Incidents: Effects of Teacher Characteristics and Contexts

Science.gov (United States)

Yoon, Jina; Sulkowski, Michael L.; Bauman, Sheri A.

2016-01-01

School is a critical context of bullying. This study investigated teacher responses to bullying incidents and the effects of individual and contextual variables on these responses. Participating teachers (N = 236) viewed streaming video vignettes depicting physical, verbal, and relational bullying and reported how they would respond to bullies and…

Dynamic response characteristics of high temperature superconducting maglev systems: Comparison between Halbach-type and normal permanent magnet guideways

International Nuclear Information System (INIS)

Wang, B.; Zheng, J.; Che, T.; Zheng, B.T.; Si, S.S.; Deng, Z.G.

2015-01-01

Highlights: • The loading weight affects the RF tremendously. • Reducing the FCH can improve the stability of the maglev vehicle. • The Halbach-type PMG has better loading capacity than the conventional PMG. • Pre-load is an effective way to enhance the dynamic characteristic of the HTS maglev vehicle. - Abstract: The permanent magnet guideway (PMG) is very important for the performance of the high temperature superconducting (HTS) system in terms of electromagnetic force and operational stability. The dynamic response characteristics of a HTS maglev model levitating on two types of PMG, which are the normal PMG with iron flux concentration and Halbach-type PMG, were investigated by experiments. The dynamic signals for different field-cooling heights (FCHs) and loading/unloading processes were acquired and analyzed by a vibration analyzer and laser displacement sensors. The resonant frequency, stiffness and levitation height of the model were discussed. It was found that the maglev model on the Halbach-type PMG has higher resonant frequency and higher vertical stiffness compared with the normal PMG. However, the low lateral stiffness of the model on the Halbach-type PMG indicates poor lateral stability. Besides, the Halbach-type PMG has better loading capacity than the normal PMG. These results are helpful to design a suitable PMG for the HTS system in practical applications.

Dynamic response characteristics of high temperature superconducting maglev systems: Comparison between Halbach-type and normal permanent magnet guideways

Energy Technology Data Exchange (ETDEWEB)

Wang, B. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, P R China (China); Zheng, J., E-mail: jzheng@swjtu.cn [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, P R China (China); Che, T. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, P R China (China); Zheng, B.T.; Si, S.S. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, P R China (China); School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, P R China (China); Deng, Z.G., E-mail: deng@swjtu.cn [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, P R China (China)

2015-12-15

Highlights: • The loading weight affects the RF tremendously. • Reducing the FCH can improve the stability of the maglev vehicle. • The Halbach-type PMG has better loading capacity than the conventional PMG. • Pre-load is an effective way to enhance the dynamic characteristic of the HTS maglev vehicle. - Abstract: The permanent magnet guideway (PMG) is very important for the performance of the high temperature superconducting (HTS) system in terms of electromagnetic force and operational stability. The dynamic response characteristics of a HTS maglev model levitating on two types of PMG, which are the normal PMG with iron flux concentration and Halbach-type PMG, were investigated by experiments. The dynamic signals for different field-cooling heights (FCHs) and loading/unloading processes were acquired and analyzed by a vibration analyzer and laser displacement sensors. The resonant frequency, stiffness and levitation height of the model were discussed. It was found that the maglev model on the Halbach-type PMG has higher resonant frequency and higher vertical stiffness compared with the normal PMG. However, the low lateral stiffness of the model on the Halbach-type PMG indicates poor lateral stability. Besides, the Halbach-type PMG has better loading capacity than the normal PMG. These results are helpful to design a suitable PMG for the HTS system in practical applications.

Effect of reservoir characteristics on the response of concrete gravity dams

International Nuclear Information System (INIS)

Baumber, T.; Ghobarah, A.

1992-01-01

In most previous analyses of dam responses to earthquake ground motion, the upstream reservoir is assumed to be infinite in length with horizontal bottom. This is rarely the actual geometry of a reservoir, as the upstream valley typically has complex geometry. A study was carried out to examine the effects of the geometry of the reservoir on the dynamic behavior of the monolith. The dam-foundation-reservoir system is modelled using a sub-structuring approach. The reservoir is modelled using a finite element formulation. The absorptive capacity of the reservoir's foundation is idealized as a one-dimensional boundary condition at the reservoir-foundation interface. The reservoir bottom is assumed to be sloping. It was found that the assumed shape of the upstream reservoir significantly affects the overall response of the dam-foundation-reservoir system. The frequencies and magnitudes of the response peaks are affected by the geometry of the reservoir. It was also found that the value of the wave reflection coefficient at the reservoir bottom has a significant effect on the system's response. 6 refs., 5 figs

An investigation of wall temperature characteristics to evaluate thermal fatigue at a T-junction pipe

International Nuclear Information System (INIS)

Miyoshi, Koji; Nakamura, Akira; Utanohara, Yoichi; Takenaka, Nobuyuki

2014-01-01

Thermal fatigue cracking may initiate at a T-junction pipe where high and low temperature fluids mix. In this study, wall temperature characteristics at a T-junction pipe were investigated to improve the evaluation method for thermal fatigue. The stainless steel test section consisted of a horizontal main pipe (diameter, 150 mm) and a T-junction connected to a vertical branch pipe (diameter, 50 mm). The inlet flow velocities in the main and branch pipes were set to 0.99 m/s and 0.66 m/s respectively to produce a wall jet pattern in which the jet from the branch pipe was bent by the main pipe flow and made to flow along the pipe wall. The temperature difference was 34.1 K. A total of 148 thermocouples were installed to measure the wall temperature on the pipe inner surface in the downstream region. The maximum of temperature fluctuation intensity on the pipe inner surface was measured as 5% of the fluid temperature difference at the inlets. The dominant frequency of the large temperature fluctuations in the region downstream from z = 0.5D m was equal to 0.2 of the Strouhal number, which was equal to the frequency caused by the vortex streets generated around the jet flow. The large temperature fluctuation was also observed with the period of about 10 s. The fluctuation was caused by spreading of the heated region in the circumferential direction. (author)

Hydrogen gas detector

International Nuclear Information System (INIS)

Bohl, T.L.

1982-01-01

A differential thermocouple hydrogen gas detector has one thermocouple junction coated with an activated palladium or palladium-silver alloy catalytic material to allow heated hydrogen gas to react with the catalyst and raise the temperature of that junction. The other juction is covered with inert glass or epoxy resin, and does not experience a rise in temperature in the presence of hydrogen gas. A coil heater may be mounted around the thermocouple junctions to heat the hydrogen, or the gas may be passed through a heated block prior to exposing it to the thermocouples

Temperature measurement on Zircaloy-clad fuel pins during high temperature excursions

International Nuclear Information System (INIS)

Meservey, R.H.

1976-04-01

The development of a sheathed thermocouple suitable for attachment to zircaloy-clad fuel rods and for use during high temperature (2,800 0 F) excursions under loss-of-coolant accident conditions is described. Development, fabrication, and testing of the thermocouples is covered in detail. In addition, the development of a process for laser welding the thermocouples to fuel rods is discussed. The thermocouples and attachment welds have been tested for resistance to corrosion and nuclear radiation and have been subjected to fast thermal cycle, risetime, and blowdown accident tests

Investigation of the response characteristics of OSL albedo neutron dosimeters in a 241AmBe reference neutron field

Science.gov (United States)

Liamsuwan, T.; Wonglee, S.; Channuie, J.; Esoa, J.; Monthonwattana, S.

2017-06-01

The objective of this work was to systematically investigate the response characteristics of optically stimulated luminescence Albedo neutron (OSLN) dosimeters to ensure reliable personal dosimetry service provided by Thailand Institute of Nuclear Technology (TINT). Several batches of InLight® OSLN dosimeters were irradiated in a reference neutron field generated by the in-house 241AmBe neutron irradiator. The OSL signals were typically measured 24 hours after irradiation using the InLight® Auto 200 Reader. Based on known values of delivered neutron dose equivalent, the reading correction factor to be used by the reader was evaluated. Subsequently, batch homogeneity, dose linearity, lower limit of detection and fading of the OSLN dosimeters were examined. Batch homogeneity was evaluated to be 0.12 ± 0.05. The neutron dose response exhibited a linear relationship (R2=0.9974) within the detectable neutron dose equivalent range under test (0.4-3 mSv). For this neutron field, the lower limit of detection was between 0.2 and 0.4 mSv. Over different post-irradiation storage times of up to 180 days, the readings fluctuated within ±5%. Personal dosimetry based on the investigated OSLN dosimeter is considered to be reliable under similar neutron exposure conditions, i.e. similar neutron energy spectra and dose equivalent values.

Non-response in a survey among immigrants in Denmark

DEFF Research Database (Denmark)

Deding, Mette; Fridberg, Torben; Jakobsen, Vibeke

The purpose of this paper is to study how various characteristics of respondents and interviewers affect non-response among immigrants. We use a survey conducted among immigrants in Denmark and ethnic Danes. First, we analyse the determinants of overall non-response. Second, we analyse how...... the determinants of contact and of response given contact differ. We find that characteristics of the respondents are important for the response rate – especially they are important for the probability of getting in contact with the respondent. The lower probability of response among immigrants compared to ethnic...

Characteristics valued by the pharmacy practice community when hiring a recently graduated pharmacist.

Science.gov (United States)

Thompson, David C; Nuffer, Wesley; Brown, Kristen

2012-11-12

To determine those characteristics that are most valued by members of the pharmacy practice community when hiring a new pharmacist. A survey instrument describing 20 characteristics that a pharmacy graduate may possess was created and sent to pharmacists licensed in Colorado. Respondents were asked to select and prioritize the top 5 characteristics considered most important in hiring a new graduate pharmacist. Responses were segregated by practice (retail vs. institutional) and/or by pharmacist role (manager vs. staff). Three hundred eighteen survey instruments were received. Having good/strong communication skills was the characteristic ranked highest by all groups. Professional behavior and being adaptable were also ranked highly. The characteristics of using the literature and punctuality ranked low overall. Differences were identified in how the groups valued some characteristics. Characteristics preferred in a new pharmacist varied depending on practice site and the managerial responsibilities of the potential employer. Some characteristics, such as communication skills and professional behavior, were considered of high value by all pharmacist groups.

Type II Superlattice as Low-Temperature Peltier Refrigerator (4K-150K)

Science.gov (United States)

2012-02-29

SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON a. REPORT...Chuanle  Zhou,  Seda  Ogrenci  Memik,  M.  Grayson,  " IOTA :  Towards   an  integrated  on-­‐chip  thermocouple  array

The relative influence of body characteristics on humid heat stress response

NARCIS (Netherlands)

Havenith, G.; Luttikholt, V. G.; Vrijkotte, T. G.

1995-01-01

The present study was designed to determine the relative importance of individual characteristics such as maximal oxygen uptake (VO2max), adiposity, DuBois body surface area (AD), surface to mass ratio (AD: mass) and body mass, for the individual's reaction to humid heat stress. For this purpose 27

Characteristics of non-response in the Danish Health Interview Surveys, 1987-1994

DEFF Research Database (Denmark)

Kjøller, Mette; Thoning, Henrik

2005-01-01

BACKGROUND: The types and quantity of non-response in surveys influence the extent to which the results may be generalized. This study analysed trends in non-response in the Danish Health Interview Surveys from 1987 to 1994 and used the National Patient Registry to assess whether non-response bia......BACKGROUND: The types and quantity of non-response in surveys influence the extent to which the results may be generalized. This study analysed trends in non-response in the Danish Health Interview Surveys from 1987 to 1994 and used the National Patient Registry to assess whether non...... respondents before data collection but similar during and after data collection. The rate was higher during the whole period among ill or disabled non-respondents. Among people who could not be contacted during the data collection period a higher admission rate was only found immediately before and during...

Alcohol-related blackouts among college students: impact of low level of response to alcohol, ethnicity, sex, and environmental characteristics

Directory of Open Access Journals (Sweden)

Priscila D. Gonçalves

2017-08-01

Full Text Available Objective: To explore how a genetically-influenced characteristic (the level of response to alcohol [LR], ethnicity, and sex relate to environmental and attitudinal characteristics (peer drinking [PEER], drinking to cope [COPE], and alcohol expectancies [EXPECT] regarding future alcohol-related blackouts (ARBs. Methods: Structural equation models (SEMs were used to evaluate how baseline variables related to ARB patterns in 462 college students over 55 weeks. Data were extracted from a longitudinal study of heavy drinking and its consequences at a U.S. university. Results: In the SEM analysis, female sex and Asian ethnicity directly predicted future ARBs (beta weights 0.10 and -0.11, respectively, while all other variables had indirect impacts on ARBs through alcohol quantities (beta weights ~ 0.23 for European American ethnicity and low LR, 0.21 for cannabis use and COPE, and 0.44 for PEER. Alcohol quantities then related to ARBs with beta = 0.44. The SEM explained 23% of the variance. Conclusion: These data may be useful in identifying college students who are more likely to experience future ARBs over a 1-year period. They enhance our understanding of whether the relationships of predictors to ARBs are direct or mediated through baseline drinking patterns, information that may be useful in prevention strategies for ARBs.

Subject-centered free-response ROC (FROC) analysis

OpenAIRE

Bandos, Andriy I.; Rockette, Howard E.; Gur, David

2013-01-01

Purpose: To develop an approach of estimating subject-centered free-response receiver operating characteristic (FROC) curve for providing patient-centered inferences regarding detection-localization characteristics of a diagnostic system.

Relationship of core exit-temperature noise to thermal-hydraulic conditions in PWRs

International Nuclear Information System (INIS)

Sweeney, F.J.; Upadhyaya, B.R.

1983-01-01

Core exit thermocouple temperature noise and neutron detector noise measurements were performed at the Loss of Fluid Test Facility (LOFT) reactor and a Westinghouse, 1148 MW(e) PWR to relate temperature noise to core thermal-hydraulic conditions. The noise analysis results show that the RMS of the temperature noise increases linearly with increasing core δT at LOFT and the commercial PWR. Out-of-core test loop temperature noise has shown similar behavior. The phase angle between core exit temperature noise and in-core or ex-core neutron noise is directly related to the core coolant flow velocity. However, if the thermocouple response time is slow, compared to the coolant transit time between the sensors, velocities inferred from the phase angle are lower than measured coolant flow velocities

Installation of borehole seismometer for earthquake characteristics in deep geological environment

Energy Technology Data Exchange (ETDEWEB)

Park, Dong Hee; Choi, Weon Hack; Cho, Sung Il; Chang, Chun Joong [KHNP CRI, Seoul (Korea, Republic of)

2014-10-15

Deep geological disposal is currently accepted as the most appropriate method for permanently removing spent nuclear fuel from the living sphere of humans. For implementation of deep geological disposal, we need to understand the geological changes that have taken place over the past 100,000 years, encompassing active faults, volcanic activity, elevation, ubsidence, which as yet have not been considered in assessing the site characteristics for general facilities, as well as to investigate and analyze the geological structures, fracture systems and seismic responses regarding deep geological environment about 500 meters or more underground. In regions with high seismic activity, such as Japan, the Western United States and Taiwan, borehole seismometers installed deep underground are used to monitor seismic activity during the course of seismic wave propagation at various depths and to study the stress changes due to earthquakes and analyze the connection to fault movements. Korea Hydro and Nuclear Power Co., Ltd. (KHNP) have installed the deep borehole earthquake observatory at depths of about 300 to 600 meters in order to study the seismic response characteristics in deep geological environment on June, 2014 in Andong area. This paper will show the status of deep borehole earthquake observatory and the results of background noise response characteristics of these deep borehole seismic data as a basic data analysis. We present here the status of deep borehole seismometer installation by KHNP. In order to basic data analysis for the borehole seismic observation data, this study shows the results of the orientation of seismometer and background noise characteristics by using a probability density function. Together with the ground motion data recorded by the borehole seismometers can be utilized as basic data for seismic response characteristics studies with regard to spent nuclear fuel disposal depth and as the input data for seismic hazard assessment that

Stimuli-Responsive Polymer-Clay Nanocomposites under Electric Fields

Science.gov (United States)

Piao, Shang Hao; Kwon, Seung Hyuk; Choi, Hyoung Jin

2016-01-01

This short Feature Article reviews electric stimuli-responsive polymer/clay nanocomposites with respect to their fabrication, physical characteristics and electrorheological (ER) behaviors under applied electric fields when dispersed in oil. Their structural characteristics, morphological features and thermal degradation behavior were examined by X-ray diffraction pattern, scanning electron microscopy and transmission electron microscopy, and thermogravimetric analysis, respectively. Particular focus is given to the electro-responsive ER characteristics of the polymer/clay nanocomposites in terms of the yield stress and viscoelastic properties along with their applications. PMID:28787852

Attenuation of hydrogen radicals traveling under flowing gas conditions through tubes of different materials

International Nuclear Information System (INIS)

Grubbs, R.K.; George, S.M.

2006-01-01

Hydrogen radical concentrations traveling under flowing gas conditions through tubes of different materials were measured using a dual thermocouple probe. The source of the hydrogen radicals was a toroidal radio frequency plasma source operating at 2.0 and 3.3 kW for H 2 pressures of 250 and 500 mTorr, respectively. The dual thermocouple probe was comprised of exposed and covered Pt/Pt13%Rh thermocouples. Hydrogen radicals recombined efficiently on the exposed thermocouple and the energy of formation of H 2 heated the thermocouple. The second thermocouple was covered by glass and was heated primarily by the ambient gas. The dual thermocouple probe was translated and measured temperatures at different distances from the hydrogen radical source. These temperature measurements were conducted at H 2 flow rates of 35 and 75 SCCM (SCCM denotes cubic centimeter per minute at STP) inside cylindrical tubes made of stainless steel, aluminum, quartz, and Pyrex. The hydrogen radical concentrations were obtained from the temperatures of the exposed and covered thermocouples. The hydrogen concentration decreased versus distance from the plasma source. After correcting for the H 2 gas flow using a reference frame transformation, the hydrogen radical concentration profiles yielded the atomic hydrogen recombination coefficient, γ, for the four materials. The methodology of measuring the hydrogen radical concentrations, the analysis of the results under flowing gas conditions, and the determination of the atomic hydrogen recombination coefficients for various materials will help facilitate the use of hydrogen radicals for thin film growth processes

Response of shallow geothermal energy pile from laboratory model tests

Science.gov (United States)

Marto, A.; Amaludin, A.

2015-09-01

In shallow geothermal energy pile systems, the thermal loads from the pile, transferred and stored in the soil will cause thermally induced settlement. This factor must be considered in the geotechnical design process to avoid unexpected hazards. Series of laboratory model tests were carried out to study the behaviour of energy piles installed in kaolin soil, subjected to thermal loads and a combination of axial and thermal loads (henceforth known as thermo-axial loads). Six tests which included two thermal load tests (35°C and 40°C) and four thermo-axial load tests (100 N and 200 N, combined with 35°C and 40°C thermal loads) were conducted. To simulate the behaviour of geothermal energy piles during its operation, the thermo-axial tests were carried out by applying an axial load to the model pile head, and a subsequent application of thermal load. The model soil was compacted at 90% maximum dry density and had an undrained shear strength of 37 kPa, thus classified as having a firm soil consistency. The behaviour of model pile, having the ultimate load capacity of 460 N, was monitored using a linear variable displacement transducer, load cell and wire thermocouple, to measure the pile head settlement, applied axial load and model pile temperature. The acquired data from this study was used to define the thermo-axial response characteristics of the energy pile model. In this study, the limiting settlement was defined as 10% of the model pile diameter. For thermal load tests, higher thermal loads induced higher values of thermal settlement. At 40°C thermal load an irreversible settlement was observed after the heating and cooling cycle was applied to the model pile. Meanwhile, the pile response to thermo-axial loads were attributed to soil consistency and the magnitude of both the axial and thermal loads applied to the pile. The higher the thermoaxial loads, the higher the settlements occurred. A slight hazard on the model pile was detected, since the settlement

Characteristics influencing therapy switch behavior after suboptimal response to first-line treatment in patients with multiple sclerosis.

Science.gov (United States)

Teter, Barbara; Agashivala, Neetu; Kavak, Katelyn; Chouhfeh, Lynn; Hashmonay, Ron; Weinstock-Guttman, Bianca

2014-06-01

Factors driving disease-modifying therapy (DMT) switch behavior are not well understood. The objective of this paper is to identify patient characteristics and clinical events predictive of therapy switching in patients with suboptimal response to DMT. This retrospective study analyzed patients with relapsing-remitting multiple sclerosis (MS) and a suboptimal response to initial therapy with either interferon β or glatiramer acetate. Suboptimal responders were defined as patients with ≥1 MS event (clinical relapse, worsening disability, or MRI worsening) while on DMT. Switchers were defined as those who changed DMT within six to 12 months after the MS event. Of 606 suboptimal responders, 214 (35.3%) switched therapy. Switchers were younger at symptom onset (p = 0.012), MS diagnosis (p = 0.004), DMT initiation (p < 0.001), and first MS event (p = 0.011) compared with nonswitchers. Compared with one relapse alone, MRI worsening alone most strongly predicted switch behavior (odds ratio 6.3; 95% CI, 3.1-12.9; p < 0.001), followed by ≥2 relapses (2.8; 95% CI, 1.1-7.3; p = 0.040), EDSS plus MRI worsening (2.5; 95% CI, 1.1-5.9; p = 0.031) and EDSS worsening alone (2.2; 95% CI, 1.2-4.1; p = 0.009). Younger patients with disease activity, especially MRI changes, are more likely to have their therapy switched sooner than patients who are older at the time of MS diagnosis and DMT initiation. © The Author(s) 2013.

The genetic influences on oxycodone response characteristics in human experimental pain

DEFF Research Database (Denmark)

Olesen, Anne Estrup; Sato, Hiroe; Nielsen, Lecia M

2015-01-01

Human experimental pain studies are of value to study basic pain mechanisms under controlled conditions. The aim of this study was to investigate whether genetic variation across selected mu-, kappa- and delta-opioid receptor genes (OPRM1, OPRK1and OPRD1, respectively) influenced analgesic respon......; therefore, variation in opioid receptor genes may partly explain responder characteristics to oxycodone....

Dose-response characteristics of low- and intermediate-risk prostate cancer treated with external beam radiotherapy

International Nuclear Information System (INIS)

Cheung, Rex; Tucker, Susan L.; Lee, Andrew K.; Crevoisier, Renaud de; Dong Lei; Kamat, Ashish; Pisters, Louis; Kuban, Deborah

2005-01-01

Purpose: In this era of dose escalation, the benefit of higher radiation doses for low-risk prostate cancer remains controversial. For intermediate-risk patients, the data suggest a benefit from higher doses. However, the quantitative characterization of the benefit for these patients is scarce. We investigated the radiation dose-response relation of tumor control probability in low-risk and intermediate-risk prostate cancer patients treated with radiotherapy alone. We also investigated the differences in the dose-response characteristics using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition vs. an alternative biochemical failure definition. Methods and materials: This study included 235 low-risk and 387 intermediate-risk prostate cancer patients treated with external beam radiotherapy without hormonal treatment between 1987 and 1998. The low-risk patients had 1992 American Joint Committee on Cancer Stage T2a or less disease as determined by digital rectal examination, prostate-specific antigen (PSA) levels of ≤10 ng/mL, and biopsy Gleason scores of ≤6. The intermediate-risk patients had one or more of the following: Stage T2b-c, PSA level of ≤20 ng/mL but >10 ng/mL, and/or Gleason score of 7, without any of the following high-risk features: Stage T3 or greater, PSA >20 ng/mL, or Gleason score ≥8. The logistic models were fitted to the data at varying points after treatment, and the dose-response parameters were estimated. We used two biochemical failure definitions. The ASTRO PSA failure was defined as three consecutive PSA rises, with the time to failure backdated to the mid-point between the nadir and the first rise. The second biochemical failure definition used was a PSA rise of ≥2 ng/mL above the current PSA nadir (CN + 2). The failure date was defined as the time at which the event occurred. Local, nodal, and distant relapses and the use of salvage hormonal therapy were also failures. Results: On the basis of the

The relationship of gender balance at work, family responsibilities and workplace characteristics to drinking among male and female attorneys.

Science.gov (United States)

Shore, E R

1997-05-01

The purpose of this study was to investigate the relationship of gender balance at work, family and home responsibilities and workplace factors to the drinking behaviors of attorneys. Using a stratified random sampling procedure, attorneys were selected from the bar associations of two large Midwestern cities. Telephone interviews were completed with 300 men and 257 women (37.3% of those originally selected), who were asked about characteristics of their work, the numbers of female attorneys they had contact with in four types of working relationships, overall and work-related drinking, and family and home responsibilities. Multiple regression and discriminant analyses were used to study the influence of these variables on drinking. Gender balance variables entered several of the analyses. For both men and women the frequency of work-related drinking positively correlated with the number of female attorneys in the organization, but was negatively related to the number of women who were peers. Family and home responsibilities entered predictive equations, both positively and negatively, for both men and women. Size of firm was positively correlated with frequency of business-related drinking and, for men, with frequency of social drinking related to work. The influence of the gender composition of the workplace on drinking behaviors may vary, for both men and women, by the type of contact involved, with closer or more active involvement with female colleagues associated with decreased frequency of drinking. Work-related drinking may also be related to home and family demands and the size of the firm, again for both genders.

Analysis of reactor material experiments investigating oxide fuel crust stability and heat transfer in jet impingement flow

International Nuclear Information System (INIS)

Sienicki, J.J.; Spencer, B.W.

1985-01-01

An analysis is presented of the crust stability and heat transfer behavior in the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten oxide fuel at approx. 160 0 K above its freezing temperature was impinged normally upon stainless steel plates initially at 300 and 385 K. The major issue is the existence of nonexistence of a stable solidified layer of fuel, or crust, interstitial to the flowing hot fuel and the steel substrate, tending to insulate the steel from the hot molten fuel. A computer model was developed to predict the heatup of thermocouples imbedded immediately beneath the surface of the plate for both of the cases in which a stable crust is assumed to be either present or absent during the impingement phase. Comparison of the model calculations with the measured thermocouple temperatures indicates that a protective crust was present over nearly all of the plate surface area throughout the impingement process precluding major melting of the plate steel. However, the experiments also show evidence for very localized and isolated steel melting as revealed by localized and isolated pitting of the steel surface and the response of thermocouples located within the pitted region

Early detection of Parkinson’s diseases by using the relation between time response and movement characteristics of human’s arms

Directory of Open Access Journals (Sweden)

Prasert Namwet

2016-08-01

Full Text Available Parkinson’s and stroke diseases are closely linked to the brain of the elderly. This study was to investigate the early detecting method of Parkinson’s disease by using the relation between the brain time response and the arm movement characteristics. 120 Healthy people were examined and classified into 4 groups of ages (60 years old.The relationship between the two parameters were conducted by using the self-made electronics set which had an accelerometer attached on the hammer; and pattern generator using star-pattern with 9-position lighted keypad. Several simple and complex light patterns were designed to test the brain function of the elderly. The experimental treatments were subjected to 4×2 Factorial Experiment in Completely Randomized Design (CRD. The results showed that the time response of the group of+60’s years old was the longest compared with other group with P<0.01. Based on the experiments on pattern-position approach, those selected samples with 4 groups of age completed the experiment with a sample pattern faster than the complex pattern in all 4 groups of age with P<0.01. The acceleration signal’s patterns in 20-40 years old and +60 years old were found polynomial and linear signal patterns, respectively. The relationship between the time response and acceleration signal were found negative monotonic correlated ( = 0.835, P < 0.01. Therefore, this finding could identify the healthy people without Parkinson’s disease with accuracy of 99.58 %. The results could be concluded that relationship between the time response and the acceleration signal could predict Parkinson’s disease and related diseases in the future.

Experimental Study of Hypersonic Wing/Fin Root Heating at Mach 8

Science.gov (United States)

2012-12-27

must be applied by hand using a thin brush and high purity gold paint. The first step in constructing the gauges is to place 17-19 quartz rods of 2mm...the expected response of 63 μV/°C (Schultz & Jones, 1973). Figure 2-1: Material makeup of the thermocouple sensoring tip and average dimensions

Types of adult attention-deficit hyperactivity disorder (ADHD): baseline characteristics, initial response, and long-term response to treatment with methylphenidate.

Science.gov (United States)

Reimherr, Fred W; Marchant, Barrie K; Gift, Thomas E; Steans, Tammy A; Wender, Paul H

2015-06-01

Much recent research describes the importance of emotional symptoms in ADHD. While there is no accepted system for including emotionality in diagnosing ADHD, the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS) provides a tool to facilitate this. It assesses a range of adult ADHD symptoms which load on two factors: inattentive and emotional dysregulation. The consistently high inattentive factor was used to define significant elevation on the more variable emotional dysregulation factor (which contains four WRAADDS domains: hyperactivity/restlessness, temper, affective lability, and emotional over-reactivity) allowing the definition of two ADHD diagnostic types. We compared these two types on a broad range of adult subject characteristics, including response to methylphenidate (MPH) treatment assessed during two clinical trials. Marked impairment in three of the four emotional domains reflected a symptom severity level equivalent to that of the inattentive factor. 59 % met this threshold, defining them as ADHD emotion dysregulation presentation, as opposed to 41 % with ADHD inattentive presentation. Cluster analysis validated these groups by generating similar clusters with 85 % agreement regarding membership. ADHD emotional dysregulation presentation subjects showed more childhood ADHD symptoms, adult symptoms of oppositional defiant disorder, and evidence of personality disorder. Both types showed similar improvement during the double-blind MPH arm of the trials and during a 6-month open-label phase. Based on the presence of symptoms of emotional dysregulation, ADHD in adults can be conceptualized as two types. Impairment and comorbidity in adults with ADHD are largely concentrated in ADHD emotional dysregulation presentation patients.

Electronic temperature control and measurements reactor fuel rig circuits

Energy Technology Data Exchange (ETDEWEB)

Glowacki, S W

1980-01-01

The electronic circuits of two digital temperature meters developed for the thermocouple of Ni-NiCr type are described. The output thermocouple signal as converted by means of voltage-to-freguency converter. The frequency is measured by a digital scaler controled by quartz generator signals. One of the described meter is coupled with digital temperature controler which drives the power stage of the reactor rig heater. The internal rig temperature is measured by the thermocouple providing the input signal to the mentioned voltage-to-frequency converter, that means the circuits work in the negative feedback loop. The converter frequency-to-voltage ratio is automatically adjusted to match to thermocouple sensitivity changes in the course of the temperature variations. The accuracy of measuring system is of order of +- 1degC for thermocouple temperature changes from 523 K up to 973 K (50degC up to 700degC).

The electronic temperature control and measurements reactor fuel rig circuits

International Nuclear Information System (INIS)

Glowacki, S.W.

1980-01-01

The electronic circuits of two digital temperature meters developed for the thermocouple of Ni-NiCr type are described. The output thermocouple signal as converted by means of voltage-to-freguency converter. The frequency is measured by a digital scaler controled by quartz generator signals. One of the described meter is coupled with digital temperature controler which drives the power stage of the reactor rig heater. The internal rig temperature is measured by the thermocouple providing the input signal to the mentioned voltage-to-frequency converter, that means the circuits work in the negative feedback loop. The converter frequency-to-voltage ratio is automatically adjusted to match to thermocouple sensitivity changes in the course of the temperature variations. The accuracy of measuring system is of order of +- 1degC for thermocouple temperature changes from 523 K up to 973 K (50degC up to 700degC). (author)

Biological Responses to Materials

Science.gov (United States)

Anderson, James M.

2001-08-01

All materials intended for application in humans as biomaterials, medical devices, or prostheses undergo tissue responses when implanted into living tissue. This review first describes fundamental aspects of tissue responses to materials, which are commonly described as the tissue response continuum. These actions involve fundamental aspects of tissue responses including injury, inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the biomaterial, medical device, or prosthesis. The second part of this review describes the in vivo evaluation of tissue responses to biomaterials, medical devices, and prostheses to determine intended performance characteristics and safety or biocompatibility considerations. While fundamental aspects of tissue responses to materials are important from research and development perspectives, the in vivo evaluation of tissue responses to these materials is important for performance, safety, and regulatory reasons.

Aspects of Responsible Tourism ‒ A Quantitative Approach

Directory of Open Access Journals (Sweden)

Olimpia State

2016-11-01

Full Text Available The concept of responsibility is well-known, but its association with tourism and connections with different aspects studied extensively, such as ethics, social responsibility, sustainable development and sustainable tourism, offers multiple research options. The main aim of this article is to define responsible tourism and to characterize responsible tourist. To define responsible tourism were seeking answers to the following questions: What are the main characteristics of responsible tourism? What known concepts can be associated with responsible tourism and with which forms of tourism is more suitable? And who are stakeholders in promotion and development of res ponsible tourism principles? To characterize responsible tourist, research answer to the following questions: What aspects define a responsible tourist? And, in this context, is a responsible attitude to travel and discover your own country? A secondary objective of the research is the statistical testing of correlations between respondents' characteristics and their opinion about the responsibility in tourism. The study is based on quantitative research ‒ a questionnaire applied to Romanian tourists in the period of March-May 2015.

Characteristics of potential repository wastes

International Nuclear Information System (INIS)

Notz, K.J.

1989-01-01

The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will be disposed of in a geologic repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. Detailed characterizations are required for all of these potential repository wastes. These characterizations include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. This information has been extracted from primary data sources, evaluated, and assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. The Characteristics Data Base provides a standard set of self-consistent data to the various areas of responsibility including systems integration and waste stream analysis, storage, transportation, and geologic disposal. The data will be used for design studies, evaluation of alternatives, and system optimization by OCRWM and supporting contractors. 7 refs., 5 figs., 7 tabs

Ignition of a Droplet of Composite Liquid Fuel in a Vortex Combustion Chamber

Science.gov (United States)

Valiullin, T. R.; Vershinina, K. Yu; Glushkov, D. O.; Strizhak, P. A.

2017-11-01

Experimental study results of a droplet ignition and combustion were obtained for coal-water slurry containing petrochemicals (CWSP) prepared from coal processing waste, low-grade coal and waste petroleum products. A comparative analysis of process characteristics were carried out in different conditions of fuel droplet interaction with heated air flow: droplet soars in air flow in a vortex combustion chamber, droplet soars in ascending air flow in a cone-shaped combustion chamber, and droplet is placed in a thermocouple junction and motionless in air flow. The size (initial radii) of CWSP droplet was varied in the range of 0.5-1.5 mm. The ignition delay time of fuel was determined by the intensity of the visible glow in the vicinity of the droplet during CWSP combustion. It was established (under similar conditions) that ignition delay time of CWSP droplets in the combustion chamber is lower in 2-3.5 times than similar characteristic in conditions of motionless droplet placed in a thermocouple junction. The average value of ignition delay time of CWSP droplet is 3-12 s in conditions of oxidizer temperature is 600-850 K. Obtained experimental results were explained by the influence of heat and mass transfer processes in the droplet vicinity on ignition characteristics in different conditions of CWSP droplet interaction with heated air flow. Experimental results are of interest for the development of combustion technology of promising fuel for thermal power engineering.

Review of resistance temperature detector time response characteristics. Safety evaluation report

International Nuclear Information System (INIS)

1981-08-01

A Resistance Temperature Detector (RTD) is used extensively for monitoring water temperatures in nuclear reactor plants. The RTD element does not respond instantaneously to changes in water temperature, but rather there is a time delay before the element senses the temperature change, and in nuclear reactors this delay must be factored into the computation of safety setpoints. For this reason it is necessary to have an accurate description of the RTD time response. This report is a review of the current state of the art of describing and measuring this time response

Apparatus Would Measure Temperatures Of Ball Bearings

Science.gov (United States)

Gibson, John C.; Fredricks, Thomas H.

1995-01-01

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.

A study on nozzle flow and spray characteristics of piezo injector for next generation high response injection

International Nuclear Information System (INIS)

Lee, Jin Wook; Min, Kyoung Doug

2006-01-01

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(Volume Of Fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response in a piezo-driven injector were reflected to spray development in agreement with the experimental spray images

24 CFR 7.16 - Responsibilities of employees.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Responsibilities of employees. 7.16... Responsibilities of employees. All employees of the Department are responsible for: (a) Being informed as to the..., females, persons with disabilities, veterans and others of diverse characteristics in the workforce, and...

Biofilms and host response - helpful or harmful

DEFF Research Database (Denmark)

Moser, Claus; Pedersen, Hannah Trøstrup; Lerche, Christian Johann

2017-01-01

infections can present in numerous ways, one common feature is involvement of the host response with significant impact on the course. A special characteristic is the synergy of the innate and the acquired immune responses for the induced pathology. Here, we review the impact of the host response...

Assessing item fit for unidimensional item response theory models using residuals from estimated item response functions.

Science.gov (United States)

Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee

2013-07-01

Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.

Quality improvement through multiple response optimization

International Nuclear Information System (INIS)

Noorossana, R.; Alemzad, H.

2003-01-01

The performance of a product is often evaluated by several quality characteristics. Optimizing the manufacturing process with respect to only one quality characteristic will not always lead to the optimum values for other characteristics. Hence, it would be desirable to improve the overall quality of a product by improving quality characteristics, which are considered to be important. The problem consists of optimizing several responses using multiple objective decision making approach and design of experiments. A case study will be discussed to show the application of the proposal method

Optimization of Performance and Emission Characteristics of Diesel Engine with Biodiesel Using Grey-Taguchi Method

Directory of Open Access Journals (Sweden)

Goutam Pohit

2013-01-01

Full Text Available Engine performances and emission characteristics of Karanja oil methyl ester blended with diesel were carried out on a variable compression diesel engine. In order to search for the optimal process response through a limited number of experiment runs, application of Taguchi method in combination with grey relational analysis had been applied for solving a multiple response optimization problem. Using grey relational grade and signal-to-noise ratio as a performance index, a particular combination of input parameters was predicted so as to achieve optimum response characteristics. It was observed that a blend of fifty percent was most suitable for use in a diesel engine without significantly affecting the engine performance and emissions characteristics.

Human disturbances, habitat characteristics and social environment generate sex-specific responses in vigilance of Mediterranean mouflon.

Directory of Open Access Journals (Sweden)

Stéphanie Benoist

Full Text Available In prey species, vigilance is an important part of the decision making process related to predation risk effects. Therefore, understanding the mechanisms shaping vigilance behavior provides relevant insights on factors influencing individual fitness. We investigated the role of extrinsic and intrinsic factors on vigilance behavior in Mediterranean mouflon (Ovis gmelini musimon×Ovis sp. in a study site spatially and temporally contrasted in human pressures. Both sexes were less vigilant in the wildlife reserve compared to surrounding unprotected areas, except for males during the hunting period. During this period, males tended to be less strictly restricted to the reserve than females what might lead to a pervasive effect of hunting within the protected area, resulting in an increase in male vigilance. It might also be a rutting effect that did not occur in unprotected areas because males vigilance was already maximal in response to human disturbances. In both sexes, yearlings were less vigilant than adults, probably because they traded off vigilance for learning and energy acquisition and/or because they relied on adult experience present in the group. Similarly, non-reproductive females benefited of the vigilance effort provided by reproductive females when belonging to the same group. However, in the absence of reproductive females, non-reproductive females were as vigilant as reproductive females. Increasing group size was only found to reduce vigilance in females (up to 17.5%, not in males. We also showed sex-specific responses to habitat characteristics. Females increased their vigilance when habitat visibility decreased (up to 13.8% whereas males increased their vigilance when feeding on low quality sites, i.e., when concomitant increase in chewing time can be devoted to vigilance with limited costs. Our global approach was able to disentangle the sex-specific sources of variation in mouflon vigilance and stressed the importance of

Dynamic response characteristics of high temperature superconducting maglev systems: Comparison between Halbach-type and normal permanent magnet guideways

Science.gov (United States)

Wang, B.; Zheng, J.; Che, T.; Zheng, B. T.; Si, S. S.; Deng, Z. G.

2015-12-01

The permanent magnet guideway (PMG) is very important for the performance of the high temperature superconducting (HTS) system in terms of electromagnetic force and operational stability. The dynamic response characteristics of a HTS maglev model levitating on two types of PMG, which are the normal PMG with iron flux concentration and Halbach-type PMG, were investigated by experiments. The dynamic signals for different field-cooling heights (FCHs) and loading/unloading processes were acquired and analyzed by a vibration analyzer and laser displacement sensors. The resonant frequency, stiffness and levitation height of the model were discussed. It was found that the maglev model on the Halbach-type PMG has higher resonant frequency and higher vertical stiffness compared with the normal PMG. However, the low lateral stiffness of the model on the Halbach-type PMG indicates poor lateral stability. Besides, the Halbach-type PMG has better loading capacity than the normal PMG. These results are helpful to design a suitable PMG for the HTS system in practical applications.

Measurement of liquid mixing characteristics in large-sized ion exchange column for isotope separation by stepwise response method

International Nuclear Information System (INIS)

Fujine, Sachio; Saito, Keiichiro; Iwamoto, Kazumi; Itoi, Toshiaki.

1981-07-01

Liquid mixing in a large-sized ion exchange column for isotope separation was measured by the step-wise response method, using NaCl solution as tracer. A 50 cm diameter column was packed with an ion exchange resin of 200 μm in mean diameter. Experiments were carried out for several types of distributor and collector, which were attached to each end of the column. The smallest mixing was observed for the perforated plate type of the collector, coupled with a minimum stagnant volume above the ion exchange resin bed. The 50 cm diameter column exhibited the better characteristics of liquid mixing than the 2 cm diameter column for which the good performance of lithium isotope separation had already been confirmed. These results indicate that a large increment of throughput is attainable by the scale-up of column diameter with the same performance of isotope separation as for the 2 cm diameter column. (author)

Study of the characteristic response of the pressure control system for the design parameters of the new turbine control system, MARK VI, in Cofrentes Nuclear Power Plant

International Nuclear Information System (INIS)

Palomo anaya, M. J.; Ruiz Bueno, G.; Mora, J. A.; Vaquer, J. I.; Bucho, L.; Lopez, B.

2010-01-01

This paper presents the results of the study of the characteristic response of the ancient Pressure and Turbine Control System for the OCP-4300 Project in the Cofrentes Nuclear Power Plant, made by Tatiana Servicios Tecnologicos in collaboration with the Institute for Industrial, Radiophysical and Environmental Safety. This work was done as one of the preliminary work necessary for replacing the old control system by Mark VI.

The characteristic response of whistler mode waves to interplanetary shocks

Science.gov (United States)

Yue, C.; Chen, L.; Bortnik, J.; Ma, Q.; Thorne, R. M.; Angelopoulos, V.; Li, J.; An, X.; Zhou, C.

2017-12-01

Magnetospheric whistler mode waves play a key role in regulating the dynamics of the electron radiation belts. Recent satellite observations indicate a significant influence of interplanetary (IP) shocks on whistler mode wave power in the inner magnetosphere. In this study, we statistically investigate the response of whistler mode chorus and plasmaspheric hiss to IP shocks based on Van Allen Probes and THEMIS satellite observations. Immediately after the IP shock arrival, chorus wave power is usually intensified, often at dawn, while plasmaspheric hiss wave power predominantly decreases near the dayside but intensifies near the nightside. We conclude that chorus wave intensification outside the plasmasphere is probably associated with the suprathermal electron flux enhancement caused by the IP shock. On the other hand, the solar wind dynamic pressure increase changes the magnetic field configuration to favor ray penetration into the nightside and promote ray refraction away from the dayside, explaining the magnetic local time (MLT) dependent responses of plasmaspheric hiss waves following IP shock arrivals.

An experimental methodology to quantify the spray cooling event at intermittent spray impact

International Nuclear Information System (INIS)

Moreira, Antonio L.N.; Carvalho, Joao; Panao, Miguel R.O.

2007-01-01

The present paper describes an experimental methodology devised to study spray cooling with multiple-intermittent sprays as those found in fuel injection systems of spark-ignition and diesel engines, or in dermatologic surgery applications. The spray characteristics and the surface thermal behaviour are measured by combining a two-component phase-Doppler anemometer with fast response surface thermocouples. The hardware allows simultaneous acquisition of Doppler and thermocouple signals which are processed in Matlab to estimate the time-varying heat flux and fluid-dynamic characteristics of the spray during impact. The time resolution of the acquisition system is limited by the data rate of validation of the phase-Doppler anemometer, but it has been shown to be accurate for the characterization of spray-cooling processes with short spurt durations for which the transient period of spray injection plays an important role. The measurements are processed in terms of the instantaneous heat fluxes, from which phase-average values of the boiling curves are obtained. Two of the characteristic parameters used in the thermal analysis of stationary spray cooling events, the critical heat flux (CHF) and Leidenfrost phenomenon, are then inferred in terms of operating conditions of the multiple-intermittent injections, such as the frequency, duration and pressure of injection. An integral method is suggested to describe the overall process of heat transfer, which accounts for the fluid-dynamic heterogeneities induced by multiple and successive droplet interactions within the area of spray impact. The method considers overall boiling curves dependant on the injection conditions and provides an empirical tool to characterize the heat transfer processes on the impact of multiple-intermittent sprays. The methodology is tested in a preliminary study of the effect of injection conditions on the heat removed by a fuel spray striking the back surface of the intake valve as in spark

Temperature Measurements of the Low-Attenuation Radiographic Ice Ball During CT-Guided Renal Cryoablation

International Nuclear Information System (INIS)

Permpongkosol, Sompol; Link, Richard E.; Kavoussi, Louis R.; Solomon, Stephen B.

2008-01-01

During renal cryoablation a low-attenuation area on CT develops around the cryoprobe. Knowledge of the temperature of the growing low-attenuation area can guide therapy and ensure lethal temperatures. Herein, we report thermocouple results and correlating CT images during the development of the low-attenuation 'radiographic ice ball.' Five patients who underwent percutaneous CT-guided renal cryoablation were identified who had thermocouples inserted and serial intraprocedural CT images that included images with thermocouple measurements of 0 o and sub-0 o C. Thermocouples had been percutaneously placed just beyond the edge of the tumors either to ensure adequate cooling or to ensure safety to adjacent critical structures. Renal cryotherapy under CT guidance produced a growing low-attenuation area corresponding to the radiographic ice ball. When the thermocouple measured 0 o C, CT images showed the thermocouple tip at the edge of the low-attenuation ice ball. At lower temperatures the tip was within the low-attenuation ice ball. We conclude that knowledge of the temperature at the ice ball edge during cryoablation can be used to predict the extent of tissue necrosis and thus provide an estimate of cryotherapy effectiveness during the procedure. Further work is necessary to establish a firm relationship between the thermal conditions and the zone of damage

Understanding the Characteristics of the Sexual Harasser.

Science.gov (United States)

Sundt, Melora

1996-01-01

Information on characteristics of harassers can help policymakers and educators develop more effective prevention programs. Results of a survey of 336 men and 333 women are presented in terms of institutional size, satisfaction with institutional response, views on the acceptability of harassment, beliefs related to harassment, and types of…

Acoustic response of Helmholtz dampers in the presence of hot grazing flow

Science.gov (United States)

Ćosić, B.; Wassmer, D.; Terhaar, S.; Paschereit, C. O.

2015-01-01

Thermoacoustic instabilities are high amplitude instabilities of premixed gas turbine combustors. Cooled passive dampers are used to attenuate or suppress these instabilities in the combustion chamber. For the first time, the influence of temperature differences between the grazing flow in the combustor and the cross-flow emanating from the Helmholtz damper is comprehensively investigated in the linear and nonlinear amplitude regime. The flow field inside the resonator and in the vicinity of the neck is measured with high-speed particle image velocimetry for various amplitudes and at different momentum-flux ratios of grazing and purging flow. Seeding is used as a tracer to qualitatively assess the mixing of the grazing and purging flow as well as the ingestion into the neck of the resonator. Experimentally, the acoustic response for various temperature differences between grazing and purging flow is investigated. The multi-microphone method, in combination with two microphones flush-mounted in the resonator volume and two microphones in the plane of the resonator entrance, is used to determine the impedance of the Helmholtz resonator in the linear and nonlinear amplitude regime for various temperatures and different momentum-flux ratios. Additionally, a thermocouple was used to measure the temperature in the neck. The acoustic response and the temperature measurements are used to obtain the virtual neck length and the effective area jump from a detailed impedance model. This model is extended to include the observed acoustic energy dissipation caused by the density gradients at the neck vicinity. A clear correlation between temperature differences and changes of the mass end-correction is confirmed. The capabilities of the impedance model are demonstrated.

A study on nozzle flow and spray characteristics of piezo injector for next generation high response injection

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Wook [Korea Institue of Machinery and Materials, Daejeon (Korea, Republic of); Min, Kyoung Doug [Seoul National University, Seoul (Korea, Republic of)

2006-06-15

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(Volume Of Fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response in a piezo-driven injector were reflected to spray development in agreement with the experimental spray images.

Reference calorimeter for radiation monitoring

International Nuclear Information System (INIS)

Zajic, V.; Vanek, V.

1978-01-01

The miniature sensor for gamma dose rate monitoring in nuclear reactors essentially consists of an absorption body symmetrically placed in a gas-tight sealed case and suspended on a metal pull-rod attached to the jacketed thermocouple bushing. The inner thermocouple is inserted into the centre of the absorption body through a slant port while the outer thermocouple is let out of the case at a point above the absorption body. (J.P.)

The EEG Photoparoxysmal Response

Directory of Open Access Journals (Sweden)

J Gordon Millichap

2008-03-01

Full Text Available Types of photosensitivity, prevalence and other characteristics of the photoparoxysmal response (PPR, associated seizures, effect of video games, and drug therapy are reviewed by the director of electroencephalography at the University of Illinois, Chicago.

The strange case of online surveys: response issues and respondent characteristics

DEFF Research Database (Denmark)

Adamsen, Jannie Mia; Rundle-Thiele, Sharyn; Mehnert, Christina

This research contributes to existing knowledge about collecting data online by analysing multiple data sets on key criteria including overall representativeness of the samples, response and break-off rates, timeliness of response and reminder effects. Across eight online surveys that initially......-30 years of age), single or in ‘other’ types of family relationships, and belong to a low-income bracket (annual household income ... a reminder 48-72 hours after the initial invitation and closing the survey one to two days later; based on our results this time-wise approach still captures 90% of respondents. This study must be viewed in light of some key limitations. Firstly, we have not considered whether there are differences...

Temperature Assessment of Heating Stage for a Thermoforming Equipment

International Nuclear Information System (INIS)

Mohd Ghazali, F.A.; Ab Rahim, M.F.; Jaafar, A.A.; Ahmad, M.N.

2016-01-01

Thermoforming is a well-known manufacturing process in the productions of various plastic household and industrial solutions. The heating of a plastic sheet allows the plastic to soften and within its forming window temperature the sheet can replicate a required shape when pressed against a mould. Hence, the heating process is an important thermoforming stage that determine uniformity of the material distribution. This article proposed an experimental approach to investigate the thermal characteristics of the heating section of a low cost thermoforming equipment designed for teaching and research purposes. The temperatures of air and a model of a stretched heated plastic sheet were measured and analysed. The experimental data indicates that the spatial temperatures distribution was not localised and the temperature history of the infrared heating agrees well with those given by fast response thermocouples. The findings suggest that the spatial uniformity of temperature can be reasonably evaluated by using the proposed method. (paper)

Dynamic characteristics analysis of deployable space structures considering joint clearance

Science.gov (United States)

Li, Tuanjie; Guo, Jian; Cao, Yuyan

2011-04-01

The clearance in joints influences the dynamic stability and the performance of deployable space structures (DSS). A virtual experimental modal analysis (VEMA) method is proposed to deal with the effects of joint clearance and link flexibility on the dynamic characteristics of the DSS in this paper. The focus is on the finite element modeling of the clearance joint, VEMA and the modal parameters identification of the DSS. The finite element models (FEM) of the clearance joint and the deployable structure are established in ANSYS. The transient dynamic analysis is conducted to provide the time history data of excitation and response for the VEMA. The fast Fourier transform (FFT) technique is used to transform the data from time domain to frequency domain. The frequency response function is calculated to identify the modal parameters of the deployable structure. Experimental verification is provided to indicate the VEMA method is both a cost and time efficient approach to obtain the dynamic characteristics of the DSS. Finally, we analyze the effects of clearance size and gravity on the dynamic characteristics of the DSS. The analysis results indicate that the joint clearance and gravity strongly influence the dynamic characteristics of the DSS.

Study of natural convection heat transfer characteristics. (1) Influence of ventilation duct height

International Nuclear Information System (INIS)

Wakamatsu, Mitsuo; Iwaki, Chikako; Ikeda, Tatsumi; Morooka, Shinichi; Ikeda, Hiroshi; Nakada, Kotaro; Masaki, Yoshikazu

2008-01-01

Natural cooling system has been investigated in waste storage. It is important to evaluate the flow by natural draft enough to removal the decay heat from the waste. In this study, we carried out the fundamental experiment of ventilation duct height effect for natural convection on vertical cylindrical heater in atmospheric air. The scale of test facility is about 4m height with single heater. The heating value is varied in the range of 33-110W, where Rayleigh number is over 10 10 . Natural convection flow rate were calculated by measured velocity with thermo anemometer in the inlet duct. The temperature of the cylindrical heater wall and fluid were measured with thermocouples. It was found that the heat transfer coefficient difference between long duct and short duct is small in this experiment. (author)

Morphologic characteristics of central pulmonary thromboemboli predict haemodynamic response in massive pulmonary embolism.

Science.gov (United States)

Podbregar, Matej; Voga, Gorazd; Krivec, Bojan

2004-08-01

On hospital admission, the morphology of the central pulmonary artery thromboemboli is an independent predictor of 30-day mortality in patients with massive pulmonary embolism (MPE). This may be due to the differential susceptibility of thromboemboli to thrombolysis. The aim of this study was to assess haemodynamic response to treatment in patients with MPE and morphologically different thromboemboli. Prospective observational study. An 11-bed closed medical ICU at a 860-bed community general hospital. Twelve consecutive patients with shock or hypotension due to MPE and central pulmonary thromboemboli detected by transesophageal echocardiography who were treated with thrombolysis between January 2000 through April 2002. Patients were divided into two groups according to the characteristics of detected central pulmonary thromboemboli: group 1, thrombi with one or more long, mobile parts; and group 2, immobile thrombi. Urokinase infusion was terminated when mixed venous oxygen saturation was stabilized above 60% for 15 min. At 2 h, the total pulmonary vascular resistance index was reduced more in group 1 than group 2 [from 27+/-12 mmHg/(l.min.m(2)) to 14+/-6 mmHg/(l.min.m(2)) (-52%) vs 27+/-8 mmHg/(l.min.m(2)) to 23+/-10 mmHg/(l.min.m(2)) (-15%), respectively, P=0.04]. In group 1 thrombolysis was terminated earlier than group 2 (89+/-40 min vs 210+/-62 min, respectively, P= 0.0024). The cumulative dose of urokinase used in group 1 was lower than group 2 (1.7+/-0.3 M i.u. vs 2.7+/-0.5 M i.u., respectively, P= 0.023). Haemodynamic stabilization is achieved faster in patients with mobile central thromboemboli detected by transesophageal echocardiography during MPE.

Low temperature transient response and electroluminescence characteristics of OLEDs based on Alq{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Yuan, Chao [Key Laboratory of Semiconductor Material Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); College of Materials Science and Optoelectronic Devices, University of Chinese Academy of Sciences, Beijing 100049 (China); Guan, Min, E-mail: guanmin@semi.ac.cn [Key Laboratory of Semiconductor Material Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Zhang, Yang [Key Laboratory of Semiconductor Material Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); College of Materials Science and Optoelectronic Devices, University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yiyang; Liu, Shuangjie [Key Laboratory of Semiconductor Material Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Zeng, Yiping [Key Laboratory of Semiconductor Material Sciences, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); College of Materials Science and Optoelectronic Devices, University of Chinese Academy of Sciences, Beijing 100049 (China)

2017-08-15

Highlights: • The dependency relation between transmission rate and electron transport layer is revealed. • The critical temperature points for the influence of luminescent materials and injection barriers on delay time are found. • The influence of light-emitting material and injection layer on carrier accumulation is quantified. - Abstract: In this work, the organic light-emitting diodes (OLEDs) based on Alq{sub 3} are fabricated. In order to make clear the transport mechanism of carriers in organic light-emitting devices at low temperature, detailed electroluminescence transient response and the current-voltage–luminescence (I–V–L) characteristics under different temperatures in those OLEDs are investigated. It founds that the acceleration of brightness increases with increasing temperature is maximum when the temperature is 200 K and it is mainly affected by the electron transport layer (Alq{sub 3}). The MoO{sub 3} injection layer and the electroluminescent layer have great influence on the delay time when the temperature is 200 K. Once the temperature is greater than 250 K, the delay time is mainly affected by the MoO{sub 3} injection layer. On the contrary, the fall time is mainly affected by the electroluminescent material. The V{sub f} is the average growth rate of fall time when the temperature increases 1 K which represents the accumulation rate of carriers. The difference between V{sub f} caused by the MoO{sub 3} injection layer is 0.52 us/K and caused by the electroluminescent material Ir(ppy){sub 3} is 0.73 us/K.

The surface renewal method for better spatial resolution of evapotranspiration measurements

Science.gov (United States)

Suvocarev, K.; Fischer, M.; Massey, J. H.; Reba, M. L.; Runkle, B.

2017-12-01

Evaluating feasible irrigation strategies when water is scarce requires measurements or estimations of evapotranspiration (ET). Direct observations of ET from agricultural fields are preferred, and micrometeorological methods such as eddy covariance (EC) provide a high quality, continuous time series of ET. However, when replicates of the measurements are needed to compare irrigation strategies, the cost of such experiments is often prohibitive and limits experimental scope. An alternative micrometeorological approach to ET, the surface renewal (SR) method, may be reduced to a thermocouple and a propeller anemometer (Castellvi and Snyder, 2009). In this case, net radiation, soil and sensible heat flux (H) are measured and latent heat flux (an energy equivalent for ET) is estimated as the residual of the surface energy-balance equation. In our experiment, thermocouples (Type E Fine-Wire Thermocouple, FW3) were deployed next to the EC system and combined with mean horizontal wind speed measurements to obtain H using SR method for three weeks. After compensating the temperature signal for non-ideal frequency response in the wavelet half-plane and correcting the sonic anemometer for the flow distortion (Horst et al., 2015), the SR H fluxes compared well to those measured by EC (r2 = 0.9, slope = 0.92). This result encouraged us to install thermocouples over 16 rice fields under different irrigation treatments (continuous cascade flood, continuous multiple inlet rice irrigation, alternate wetting and drying, and furrow irrigation). The EC measurements with net radiometer and soil heat flux plates are deployed at three of these fields to provide a direct comparison. The measurement campaign will finish soon and the data will be processed to evaluate the SR approach for ET estimation. The results will be used to show better spatial resolution of ET measurements to support irrigation decisions in agricultural crops.

Biosynthetic hydrogels--studies on chemical and physical characteristics on long-term cellular response for tissue engineering.

Science.gov (United States)

Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

2014-07-01

Biosynthetic hydrogels can meet the drawbacks caused by natural and synthetic ones for biomedical applications. In the current article we present a novel biosynthetic alginate-poly(propylene fumarate) copolymer based chemically crosslinked hydrogel scaffolds for cardiac tissue engineering applications. Partially crosslinked PA hydrogel and fully cross linked PA-A hydrogel scaffolds were prepared. The influence of chemical and physical (morphology and architecture of hydrogel) characteristics on the long term cellular response was studied. Both these hydrogels were cytocompatible and showed no genotoxicity upon contact with fibroblast cells. Both PA and PA-A were able to resist deleterious effects of reactive oxygen species and sustain the viability of L929 cells. The hydrogel incubated oxidative stress induced cells were capable of maintaining the intra cellular reduced glutathione (GSH) expression to the normal level confirmed their protective effect. Relatively the PA hydrogel was found to be unstable in the cell culture medium. The PA-A hydrogel was able to withstand appreciable cyclic stretching. The cyclic stretching introduced complex macro and microarchitectural features with interconnected pores and more structured bound water which would provide long-term viability of around 250% after the 24th day of culture. All these qualities make PA-A hydrogel form a potent candidate for cardiac tissue engineering. © 2013 Wiley Periodicals, Inc.

Temperature measurements at the LMFBR core outlet

International Nuclear Information System (INIS)

Argous, J.P.; Berger, R.; Casejuane, R.; Fournier, C.; Girard, J.P.

1980-04-01

Over the last few years the temperature sensors used to measure the subassembly outlet temperature in French designed LMFBRs have been modified, basically in an effort to reduce the dispersion of the chromel-alumel thermocouple time constant, and to extend the frequency spectrum of the measurement signals by adding a steel electrode to from a stainless steel-sodium thermocouple. The result of this evolution is the temperature probe immersed in sodium which will be used in the SUPER PHENIX reactor. This paper describes the tests already completed or in progress on this probe. It also presents measurement data on the two basic probe parameters: the thermoelectric power of the stainless steel-sodium thermocouple and the time constant of the chromel-alumel thermocouple

DESEMPENHO DE DIFERENTES BITOLAS DE TERMOPAR EM UM PSICRÔMETRO ASPIRADO DE BAIXO CUSTO

Directory of Open Access Journals (Sweden)

CLÁUDIO RICARDO DA SILVA

2011-01-01

Full Text Available The objective of this work was to evaluate an aspirated psychrometer constructed under different thermocouple gauges. Were used three thermocouple copper-constantan gauge: 24 AWG (0.511 mm of diameter, 32 AWG (0.202 mm of diameter and 40 AWG (0.080 mm of diameter. The thermocouples were placed into a single psychrometer and each one positioned side by side at a distance of approximately 30 mm each other. Hourly air temperature and humidity values obtained from each gauge were compared with the values obtained with a thermistor and capacitive hygrometer. The results showed that the thermocouple gauges used (24, 32 and 40 AWG had high correlation and accuracy with values determined by the hygrometer (r2 > 0.97, RMSE P 3.91%.

A prototype of on-line digital flow rate meter based on cross-correlation principle

International Nuclear Information System (INIS)

Sun Xiaodong; Dai Zhenxi; Xu Jijun

1997-01-01

An on-line, digital prototype of flow rate measurement system based on cross-correlation principle is developed. Laboratory measurements using the prototype show that sufficiently large temperature fluctuations exist naturally and that measurements are possible. Temperature fluctuations are detected by two identical thermocouples spaced along the flow direction and are pre-processed by a thermocouple signal amplifier. The pre-processed temperature fluctuations are analyzed by a cross-correlator which measures the transit time of temperature fluctuations between two thermocouples directly. Thus, the so-called correlation velocity can be determined by a chip microprocessor 8031. Experimental results with single-phase under steady conditions also show that the distance between two thermocouples and the Reynolds number of fluid are the most important parameters to the measurement

Miniaturized heat flux sensor for high enthalpy plasma flow characterization

International Nuclear Information System (INIS)

Gardarein, Jean-Laurent; Battaglia, Jean-Luc; Lohlec, Stefan; Jullien, Pierre; Van Ootegemd, Bruno; Couzie, Jacques; Lasserre, Jean-Pierre

2013-01-01

An improved miniaturized heat flux sensor is presented aiming at measuring extreme heat fluxes of plasma wind tunnel flows. The sensor concept is based on an in-depth thermocouple measurement with a miniaturized design and an advanced calibration approach. Moreover, a better spatial estimation of the heat flux profile along the flow cross section is realized with this improved small sensor design. Based on the linearity assumption, the heat flux is determined using the impulse response of the sensor relating the heat flux to the temperature of the embedded thermocouple. The non-integer system identification (NISI) procedure is applied that allows a calculation of the impulse response from transient calibration measurements with a known heat flux of a laser source. The results show that the new sensor leads to radially highly resolved heat flux measurement for a flow with only a few centimetres in diameter, the so far not understood non-symmetric heat flux profiles do not occur with the new sensor design. It is shown that this former effect is not a physical effect of the flow, but a drawback of the classical sensor design. (authors)

Temperature distribution in target tumor tissue and photothermal tissue destruction during laser immunotherapy

Science.gov (United States)

Doughty, Austin; Hasanjee, Aamr; Pettitt, Alex; Silk, Kegan; Liu, Hong; Chen, Wei R.; Zhou, Feifan

2016-03-01

Laser Immunotherapy is a novel cancer treatment modality that has seen much success in treating many different types of cancer, both in animal studies and in clinical trials. The treatment consists of the synergistic interaction between photothermal laser irradiation and the local injection of an immunoadjuvant. As a result of the therapy, the host immune system launches a systemic antitumor response. The photothermal effect induced by the laser irradiation has multiple effects at different temperature elevations which are all required for optimal response. Therefore, determining the temperature distribution in the target tumor during the laser irradiation in laser immunotherapy is crucial to facilitate the treatment of cancers. To investigate the temperature distribution in the target tumor, female Wistar Furth rats were injected with metastatic mammary tumor cells and, upon sufficient tumor growth, underwent laser irradiation and were monitored using thermocouples connected to locally-inserted needle probes and infrared thermography. From the study, we determined that the maximum central tumor temperature was higher for tumors of less volume. Additionally, we determined that the temperature near the edge of the tumor as measured with a thermocouple had a strong correlation with the maximum temperature value in the infrared camera measurement.

Cyclic characteristics of earthquake time histories

International Nuclear Information System (INIS)

Hall, J.R. Jr; Shukla, D.K.; Kissenpfennig, J.F.

1977-01-01

From an engineering standpoint, an earthquake record may be characterized by a number of parameters, one of which is its 'cyclic characteristics'. The cyclic characteristics are most significant in fatigue analysis of structures and liquefaction analysis of soils where, in addition to the peak motion, cyclic buildup is significant. Whereas duration peak amplitude and response spectra for earthquakes have been studied extensively, the cyclic characteristics of earthquake records have not received an equivalent attention. Present procedures to define the cyclic characteristics are generally based upon counting the number of peaks at various amplitude ranges on a record. This paper presents a computer approach which describes a time history by an amplitude envelope and a phase curve. Using Fast Fourier Transform Techniques, an earthquake time history is represented as a projection along the x-axis of a rotating vector-the length the vector is given by the amplitude spectra-and the angle between the vector and x-axis is given by the phase curve. Thus one cycle is completed when the vector makes a full rotation. Based upon Miner's cumulative damage concept, the computer code automatically combines the cycles of various amplitudes to obtain the equivalent number of cycles of a given amplitude. To illustrate the overall results, the cyclic characteristics of several real and synthetic earthquake time histories have been studied and are presented in the paper, with the conclusion that this procedure provides a physical interpretation of the cyclic characteristics of earthquakes. (Auth.)

Thermoluminescent characteristics of synthetic hydroxyapatite (SHAp)

International Nuclear Information System (INIS)

Alvarez, R.; Rivera, T.; Guzman, J.; Piña-Barba, M.C.; Azorin, J.

2014-01-01

This paper presents the experimental results of the thermoluminescent (TL) characteristics of synthetic hydroxyapatite (SHAp) obtained by the sol–gel method. For preparation of the SHAp powders, phosphorus pentoxide (P 2 O 5 ) and calcium nitrate tetrahydrated (Ca(NO 3 ) 2 –4H 2 O) were used. The powders obtained were submitted at different temperatures. The structural and morphological characterization were carried out using X-ray diffraction (XRD) and scanning electron microscopy techniques. TL glow curve exhibited two peaks centered at around 200 °C and 300 °C. TL response of SHAp as a function of gamma absorbed dose was linear over a wide dose range. Fading of the storage information in the samples irradiated was also studied. The experimental results show that the synthetic hydroxyapatite obtained by the sol–gel method may have used in gamma radiation dosimetry applications. - highlights: • Dosimetric characteristics of SHAp under gamma irradiation effect were analyzed • SHAp powders were obtained by Sol–Gel method • Fading anomalous of HAp was performed showing 15% during 90 days • SHAp showed good dosimetric characteristics. • Dosimetric characteristics of SHAp have not been reported yet in the literature before this paper

Autistic characteristics in adults with epilepsy and perceived seizure activity.

Science.gov (United States)

Wakeford, SallyAnn; Hinvest, Neal; Ring, Howard; Brosnan, Mark

2015-11-01

The prevalence of autism spectrum disorders in epilepsy is approximately 15%-47%, with previous research by Wakeford and colleagues reporting higher autistic traits in adults with epilepsy. The aim of this study was to investigate autistic characteristics and their relationship to having seizures by employing two behavioral assessments in two samples: adults with epilepsy and controls. The study employed the Social Responsiveness Scale - Shortened (SRS-S) (patients with epilepsy (n=76), control (n=19)) and the brief Repetitive Behavior Scale - Revised (RBS-R) (patients with epilepsy (n=47), control (n=21)). This study employed a unique method to quantify the extent to which autistic characteristics are related to perceived mild seizure activity. Adults with epilepsy were instructed to rate their usual behavior on each assessment and, at the same time, rate their behavior again when they perceived that they were having mild seizure activity. Significantly higher SRS-S scores were related to having a diagnosis of epilepsy and were perceived by adults with epilepsy to increase during mild seizure activity. These scores positively correlated with antiepileptic drug control. No difference was found for RBS-R scores in adults with epilepsy compared with controls. Together, these results suggest that adults with epilepsy have higher autistic characteristics measured by the social responsiveness scale, while sameness behaviors remain unimpaired. The autistic characteristics measured by the social responsiveness scale were reported by adults with epilepsy to be more severe during their mild seizure activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Roman Catholic beliefs produce characteristic neural responses to moral dilemmas.

Science.gov (United States)

Christensen, Julia F; Flexas, Albert; de Miguel, Pedro; Cela-Conde, Camilo J; Munar, Enric

2014-02-01

This study provides exploratory evidence about how behavioral and neural responses to standard moral dilemmas are influenced by religious belief. Eleven Catholics and 13 Atheists (all female) judged 48 moral dilemmas. Differential neural activity between the two groups was found in precuneus and in prefrontal, frontal and temporal regions. Furthermore, a double dissociation showed that Catholics recruited different areas for deontological (precuneus; temporoparietal junction) and utilitarian moral judgments [dorsolateral prefrontal cortex (DLPFC); temporal poles], whereas Atheists did not (superior parietal gyrus for both types of judgment). Finally, we tested how both groups responded to personal and impersonal moral dilemmas: Catholics showed enhanced activity in DLPFC and posterior cingulate cortex during utilitarian moral judgments to impersonal moral dilemmas and enhanced responses in anterior cingulate cortex and superior temporal sulcus during deontological moral judgments to personal moral dilemmas. Our results indicate that moral judgment can be influenced by an acquired set of norms and conventions transmitted through religious indoctrination and practice. Catholic individuals may hold enhanced awareness of the incommensurability between two unequivocal doctrines of the Catholic belief set, triggered explicitly in a moral dilemma: help and care in all circumstances-but thou shalt not kill.

A Grid of Fine Wire Thermocouples to Study the Spatial Coherence of Turbulence within Katabatic Flow through a Vineyard Canopy

Science.gov (United States)

Everard, K.; Christen, A.; Sturman, A.; Skaloud, P.

2016-12-01

Knowledge of the dynamics and thermodynamics of katabatic flow is relevant in vineyards, where grapevines are sensitive to temperature changes (frost protection and cooling). Basic understanding of the occurrence and evolution of, and turbulence within, katabatic flow is well known over bare slopes. However, little work has been completed to extend this understanding to mid-sized canopies and how the presence of a canopy affects the turbulent exchange of momentum and heat within the flow. Measurements were carried out over a 6° vineyard slope near Oliver, BC, Canada in the Okanagan Valley between July 5 and July 22, 2016. The set-up consisted of an array of five vertically arranged CSAT 3D (Campbell Scientific, Inc.) ultrasonic anemometers at z = 0.45 m, 0.90 m, 1.49 m, 2.34 m, and 4.73 m above ground level (AGL), and a 2-D grid of 40 Type-E (copper-constantan) fine-wire thermocouples (FWTC) arranged at the same heights as the CSAT 3D array on 8 masts extending in the upslope (flow) direction at locations x = 0.0 m (CSAT 3D tower), 0.5 m, 1.0 m, 2.0 m, 4.0 m, 8.0 m, 16.0 m, and 32.0 m. The FWTC array formed a sheet of 40 sampling points in the upslope-vertical plane. The height of the grapevine canopy (h) was approximately 2 m AGL, and rows were aligned along the local slope direction with a row spacing of 2.45 m. CSAT-3s were sampled at 60 Hz with 20 Hz data recording, the FWTCs were sampled at 2 Hz, all synchronized by a data logger. Katabatic flow was observed on several nights during the campaign, with a wind speed maximum located within the canopy. This contribution will focus on the measurement techniques, combining ultrasonic anemometer data with the spatially synchronized FWTC array using image process techniques. We identify the dynamics and structure of the katabatic flow, relevant for heat exchange, using the spatial coherence of the temperature field given by the FWTC array. Improved knowledge of the vertical structure and the dynamics of katabatic

The socio-economic patterning of survey participation and non-response error in a multilevel study of food purchasing behaviour: area- and individual-level characteristics.

Science.gov (United States)

Turrell, Gavin; Patterson, Carla; Oldenburg, Brian; Gould, Trish; Roy, Marie-Andree

2003-04-01

To undertake an assessment of survey participation and non-response error in a population-based study that examined the relationship between socio-economic position and food purchasing behaviour. The study was conducted in Brisbane City (Australia) in 2000. The sample was selected using a stratified two-stage cluster design. Respondents were recruited using a range of strategies that attempted to maximise the involvement of persons from disadvantaged backgrounds: respondents were contacted by personal visit and data were collected using home-based face-to-face interviews; multiple call-backs on different days and at different times were used; and a financial gratuity was provided. Non-institutionalised residents of private dwellings located in 50 small areas that differed in their socio-economic characteristics. Rates of survey participation - measured by non-contacts, exclusions, dropped cases, response rates and completions - were similar across areas, suggesting that residents of socio-economically advantaged and disadvantaged areas were equally likely to be recruited. Individual-level analysis, however, showed that respondents and non-respondents differed significantly in their sociodemographic and food purchasing characteristics: non-respondents were older, less educated and exhibited different purchasing behaviours. Misclassification bias probably accounted for the inconsistent pattern of association between the area- and individual-level results. Estimates of bias due to non-response indicated that although respondents and non-respondents were qualitatively different, the magnitude of error associated with this differential was minimal. Socio-economic position measured at the individual level is a strong and consistent predictor of survey non-participation. Future studies that set out to examine the relationship between socio-economic position and diet need to adopt sampling strategies and data collection methods that maximise the likelihood of recruiting

Electromagnetic Transient Response Analysis of DFIG under Cascading Grid Faults Considering Phase Angel Jumps

DEFF Research Database (Denmark)

Wang, Yun; Wu, Qiuwei

2014-01-01

This paper analysis the electromagnetic transient response characteristics of DFIG under symmetrical and asymmetrical cascading grid fault conditions considering phaseangel jump of grid. On deriving the dynamic equations of the DFIG with considering multiple constraints on balanced and unbalanced...... conditions, phase angel jumps, interval of cascading fault, electromagnetic transient characteristics, the principle of the DFIG response under cascading voltage fault can be extract. The influence of grid angel jump on the transient characteristic of DFIG is analyzed and electromagnetic response...

Generalized analytic solutions and response characteristics of magnetotelluric fields on anisotropic infinite faults