The purpose of development work on the Johnson noise power thermometer (JNPT) was to apply the work of Nyquist, who showed that the mean-squared noise voltage spectrum appearing across an unloaded resistor of value R is given by anti e sub n (2) = 4hfR (exp(hf/kT) - 1)) where anti e sub n (2) has the units volts squared per unit ...

The purpose of development work on the Johnson noise power thermometer (JNPT) was to apply the work of Nyquist, who showed that the mean-squared noise voltage spectrum appearing across an unloaded resistor of the value R is given by anti e sub n (2) = 4hfR (exp(hf/kT) - 1)) where anti e sub n (2) has the units volts squared per unit ...

The authors report preliminary measurements on several current sensing noise thermometers presently under study in the laboratory. The emphasis of the work is to produce a fast practical absolute thermometer that can be used over the entire temperature range from 4.2 K to 0.05 mK. A practical thermometer based on commercially available rf SQUIDs useful in ...

Method and device for direct, non-contact temperature measure of a body. A laser beam is reflected from the surface of the body and detected along with the Planck radiation. The detected signal is analyzed using signal correlation technique to generate an output signal proportional to the Johnson noise introduced into the reflected laser beam as a direct ...

Methods for in situ calibration of reactor plant platinum resistance thermometers using Johnson noise measurements were tested in the laboratory and in two operating reactors: Diablo Canyon and Sequoyah. The Johnson noise methods provide an absolute measurement of the thermometer temperature ...

Methods have been demonstrated in operating nuclear plants for the in situ calibration of resistance thermometers with agreement between measured noise temperatures and dc calibration temperatures well within these required by the plant. A comparison of the results of Johnson noise power testing results and uncertainties, the ...

The Josephson junction can be used to convert voltage into frequency and thus it can be used to convert voltage fluctuations generated by Johnson noise in a resistor into frequency fluctuations. As a consequence, the temperature of the resistor can be defined by measuring the variance of the frequency fluctuations. Unfortunately, the ...

Technical advances and new results in noise thermometry at temperatures near the tin freezing point and the zinc freezing point using a quantized voltage noise source (QVNS) are reported. The temperatures are derived by comparing the power spectral density of QVNS synthesized noise with that of Johnson ...

.................................................................. 10 Thermodynamic fluctuation noise. .......................................... 10 Thermometer Johnson background noise. ...................................................... 14 Additional thermometer noise ...

Significant progress in the field of Johnson noise thermometry has occurred since the 1971 survey of Kamper. This paper will review the foundation work of Johnson noise thermometry, survey the basic methods which do not utilize quantum devices for noise thermometry for industrial temperatures, ...

The theoretical foundation is presented for Johnson noise thermometry. Basic methods for implementation of practical noise thermometers that use conventional electronic signal-processors are surveyed. Applications of noise thermometry in temperature scale metrology and process temperature instrumentation are ...

Fabrication specifications, parts list, photographs, drawings, and printed circuit photomasters are given for a preamplifier for a Johnson noise power thermometer.

Absolute GNSS Antenna Calibration with a Robot: Repeatability of Phase Variations,. Calibration of GLONASS and. Determination of Carrier-to-Noise Pattern ...

Audio frequency noise density measurements were performed on weakly superconducting proximity effect bridges on using a cooled transformer and room temperature low noise preamplifier. The noise temperature of the measuring system is approximately 4$sup 0$K for a 0.9 $Omega$ resistor. Noise density was ...

An instrument for the definition of absolute temperature on the scale of one micron based on the measurement of Johnson noise in a small metallic resistor has been constructed. The instrument uses conventional monolithic amplifiers and signal processing circuitry and a custom sensor fabricated by bulk micromachining and electron-beam ...

Contents: Predicting community response to aircraft noise; Judgments of the relative and absolute acceptability of actual and recorded aircraft noise; An analysis of some factors affecting community-airport decision-making; The reduction of aircraft noise...

Contents: Predicting community response to aircraft noise; Judgments of the relative and absolute acceptability of actual and recorded aircraft noise; An analysis of some factors affecting community-airport decision-making; The reduction of aircraft noise...

... Dark noise occurs prior to adaptation, determines dark-adapted absolute thresholds, and mimics stationary external noise. ...

... we will address here are: pitch and roll improvements, L-Band absolute and ocean calibration, instrument stability, and environmental noise sources ...

... such as optical clock distribution [1], and photonic analog to digital ... This noise spectral density shows typical characteristics of mode-locked ...

| The absolute value penalty really changes the estimator! EPD also works here. #12;John Lennon with outlier noise

... Since this is a noise that exists in all detectors at a finite temperature, it sets the absolute limit of detectivity that no detector of whatever type or ...

semiconductors are insulators at absolute zero with conductivities less than ... semiconductor's device properties. In fact, it is the ability to precisely ...

Thermal noise measurements on semiconductors and metals indicate that first, 1/f noise does not require a long-term steady current, and second, that the fluctuations in the mean-square Johnson noise voltage have a 1/f spectrum that arises from resistance ...

... This plot shows that the ambient noise in San Diego harbor is higher than the bottlenose dolphin threshold measured by Johnson [10], but lower ...

... Title : 10-WATT WIDE-BAND NOISE GENERATOR EQUIPMENT,. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CALIF. ...

A dual-mode Johnson noise and DC resistance thermometer capable of use in control systems where prompt indications of temperature changes and long term accuracy are needed. A resistance-inductance-capacitance (RLC) tuned circuit produces a continuous voltage signal for Johnson noise temperature measurement. The RLC ...

A noise phenomenon which is often dominant at low frequencies is comprised of those processes which are called 1/f noise, flicker effect, and sporadic processes. These processes are characterized by a power spectral density which varies as 1/((the absolut...

Measurements of the absolute value of electromagnetic noise and attenuation along a hoist rope were made in an operating hard-rock mine, Lucky Friday Mine, located near Wallace, Idaho. Spectra of electromagnetic noise generated by various pieces of equipm...

A computer model for the dc SQUID is described which predicts signal and noise as a function of various SQUID parameters. Differential equations for the voltage across the SQUID including the Johnson noise in the shunted junctions are integrated stepwise in time.

By scattering theory we show that spin current noise in normal electric conductors in contact with nanoscale ferromagnets increases the magnetization noise by means of a fluctuating spin-transfer torque. Johnson-Nyquist noise in the spin current is related to the increased Gilbert damping due to spin pumping, in ...

Photovoltaic indium antimonide detectors have been operated at temperatures Johnson noise limited performance is realized. Under such conditions the noise equivalent power (NEP) is completely determined by the detector operating temperature, resistance, and quantum ...

the random detector noise limit is of order of a few times ... Introduction. The FIRAS (Far Infrared Absolute Spectrophotometer) instrument ...... The rst frequency modulation occurs when the velocity of the MTM uctuates, ..... For each telemetered interferogram, the ight electronics generates a pseudo-random DC ...

limits on the performance of noise thermometers. The most successful technique developed to date noise superimposed on the thermal noise signal. In use, the thermometer switches between a reference switched-input correlation thermometer. Measurement time: Because the noise signal is random, the signal

... k is Boltzmann's constant (1.38 x 10-23 V-sec/oK), Tb is the absolute temperature of the black body, and A is the radiated wavelength. ...

A temperature measuring system is described comprising: a sensor having a resistor; first signal processor means, having a current source constantly coupled to the sensor, for continuously producing a first temperature signal based on the DC resistance of the sensor resistor; and second signal processor means, coupled to the sensor, for continuously producing a second temperature signal based ...

Three stages of visual processing determine how internal noise appears to an external observer: light adaptation, contrast gain control, and a postsensory/decision stage. Dark noise occurs prior to adaptation, determines dark-adapted absolute thresholds, ...

The noise thermometry (NT) is a temperature measuring method by which the absolute temperature measurement can be performed with a very high accuracy and without any influence of ambient environments and of the thermal history of its NT sensor (electric r...

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating hardrock mine, Grace Mine, located near Morgantown, Pennsylvania. Diesel-powered haulage equipment is used in this mine, and the electro...

silence". Mathematically, the baseline is represented by a constant 0. All signals, including noise, the baseline can logically be set at absolute silence and mathematically fixed at 0. When noise is used of an auditory signal involves both transduction by hair cells and synaptic integration by innervating spiral

In the GaAs semiconductor laser balanced mixer heterodyne receiver of Abbas and Chan (1983), the photocurrent fluctuation due to local oscillator wave intensity noise was suppressed, but the absolute quantum noise level calibration was not clarified. In this paper, the results of experimental calibration of the quantum ...

summer of 2004. One of the modifications included enclosing the pump in a case to reduce noise. TURNING. DOWN THE. HEAT. WITH. COOL. INVENTION ...

Sep 10, 1971 ... aircraft noise pollution. It is also. Houston and 2 residential lots in northeast developing remote sensors for use. A variety of propellant ...

and beam lengths ranging from 700 /Lmto 8300 /Lm. The measurements directly .... the island through measuring its Johnson noise. The other is a heater. ...

Acoustic Testing to fulfill facility schedule. * Modal Testing to fulfill facility schedule. * Noise Control Demonstrations, Consultations, and Measurements ...

... Descriptive Note : Rept. no. 1 (Triannual) 28 Jul-30 Nov 78,. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CALIF. ...

... Corporate Author : JOURNAL ARTICLE-UNIDENTIFIED SOURCE. Personal Author(s) : HALL,DNB. Report Date : FEB 1975. ...

... Personal Author(s) : Johnson,H. Kevin ; Katz,Walter M. ... were analyzed, and high resolution spectra were developed over a frequency range of 0 to ...

pressure altitude, (2) outside skin temperature,. (3) inside skin temperature,. (4) cabin air temperature,. (5) noise level, and (6) vibration. ...

... WAVE TUBE. Descriptive Note : Final rept. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CA. Personal Author ...

... Among these are Casimir-Polder forces, Johnson noise, patch potentials ... the atom surface distance mitigates the deleterious effects including atom ...

Interference detection in Gaussian noise is proposed. It can be applied for easy detection and editing of interference lines in radio spectral line observations. One does not need to know the position of occurrence or keep track of interference in the band. By using statistical properties of N-channel Gaussian noise it is possible to differentiate ...

The utilization of thermal fluctuations or Johnson/Nyquist noise as a generalized spectroscopic technique to experimentally measure transport properties is applied to Pt and W metal films. Through cross-correlation and autocorrelation functions obtained from voltage power spectral density measurements, multiple transport coefficients are obtained through ...

Methods have been demonstrated in operating nuclear plants for the in situ calibration of resistance thermometers with agreement between measured noise temperatures and dc calibration temperatures well within these required by the plant. A comparison of t...

In contrast to the thermometers which have been previously used (thermocouples, resistance thermometers, etc.), the noise thermometer is independent of all environmental influences, such as reactor radiation or atmosphere. It is independent of its thermal and mechanical pretreatment and of the material used. Consequently, the noise thermometer ...

in relation to the different vegetation and environmental noise; (2) in most localities, call attenuation s of recorded environmental noise preceding each signal. We analysed sound attenuation and studied sound) and environmental noise with the formula: Ls = Lc - (Rc - Rs) Where Ls = absolute RMS SPL of the signal ...

, expressions for the first-order noise and signal�noise intermodulation terms are computed. The procedure is determined by a specified maximal distortion level, for harmonic or intermodulation distortion. The absolute�noise intermodulation, both in static and dynamic TL circuits. A current-mode approach is followed, since TL cir- ...

We present colour transformations for the conversion of the W1 and W2 magnitudes of the Wide-field Infrared Survey Explorer (WISE) photometric system to the Johnson-Cousins BVRI, Sloan Digital Sky Survey gri and Two-Micron All-Sky Survey JHKs photometric systems, for dwarfs. The W3 and W4 magnitudes were not considered due to their insufficient ...

Circuits, parts lists, fabrication and test instructions for a NIM-modular main bandpass amplifier and filter are furnished suitable for use with a Johnson noise thermometer. These amplifiers are designed for use with the dual low-noise preamplifier described in CAPE-2567; two main bandpass amplifiers are required for ...

A method of coupling the low-temperature induction coil of an NMR or SQUID system to a preamplifier is proposed. This method greatly reduces the Johnson noise generated by line losses. A suitable 9-K noise-temperature GaAs FET, liquid nitrogen cooled preamplifier is described. The coupling scheme and preamplifier will yield a ...

Metamaterials made up of resonant elements containing lossy metallic conductors will invariably give rise to Johnson noise. A model based on nearest neighbor interaction of magnetically coupled elements is shown to predict the propagation of noise waves and the excitation of resonances in regular arrays. The power spectral density ...

We detail the design and operation of an electrical substitution radiometer, which measures the absolute fluence of thermal neutron beams based on neutron absorption in a 6Li-rich metallic alloy. We demonstrate that the device possesses a linear response to electrical power in the 50-500 nW range with better than 0.1% absolute accuracy and negligible zero ...

To study the acoustic properties of the Antarctic ice the South Pole Acoustic Test Setup (SPATS) was installed in the upper part of drill holes for the IceCube neutrino observatory. An important parameter for the design of a future acoustic neutrino telescope is the acoustic background noise in the ice and its spatial and temporal variations. We study the ...

Evaluation of the inherent noise levels of high-responsivity sensors is critical for good design but this area is often treated casually until testing reveals a problem. Careful noise analysis early in the design process can save time, effort, and much frustration and reveal options for better performance. Once the sensor is fabricated, careful measurement ...

Dual-mode Johnson noise and dc resistance thermometers can be used in control systems where prompt indications of temperature changes and long-term accuracy are needed. Such a thermometer is being developed for the SP-100 space nuclear electric power syst...

separate high input impedance amplifiers. The output of these amplifiers is partially correlated since each Institute leading the Korean JNT tasks, is focused on implementing a dual mode resistance and Johnson noise packaged in a shielded aluminum enclosure and a coaxial signal interconnection scheme has been implemented

Author names on the end of a species epithet are essential to stable taxonomy. These names are absolutely required in the case of homonymy, but they are also useful for obtaining original descriptions, locating type depositories, and determining the quality of a species concept. In this paper I ar...

Aircraft flyovers heard in high ambient noise urban environments are composed in large part of high absolute level, broadband noise. In contrast, noise exposure created en route by aircraft powered by unducted fan engines is expected to be relatively low in level, but to contain prominent low frequency tonal ...

A total of 96 absolute gravity (AG) measurements at the Membach station and 221 at the Proudman Oceanographic Laboratory (POL) is analyzed for noise content. The lengths of the series were around 10 years (POL) and 8 years (Membach). First the noise at frequencies lower than 1 cpd is studied. This noise consists in ...

This paper present the results of an extensive study of the effect of a filter upon the performance of a resistive SQUID noise thermometer used to define an absolute temperature scale below 1 K. Agreement between the model for this effect and the experimental results indicated that the temperature scale defined by the noise thermometer ...

Some recent tomographic studies of the Earth (e.g., Rodgers and Wahr, 1993; Vasco and Johnson, 1998; Boschi and Dziewonski, 2002) have pointed out a discrepancy between results using core-reflected phases PcP versus those making use of core-diffracted phases (PKP). In particular, published maps of the CMB topography obtained using the different types of phases show significant ...

The temperature dependence of the magnetic penetration depth in a superconductor, in the kinetic inductance limit, is proposed as a basis for a sensitive thermometer. Considered as a bolometer, the noise equivalent power from the sum of the Johnson noise and the preamplifier noise can be reduced to about 7 x 10/sup ...

The power spectra of fluctuations in the mean square of the Johnson-noise voltage across small semiconductor and metal films in thermal equilibrium were measured down to 10/sup -4/ Hz. The spectra have a 1/f-like behavior that matches the resistance-fluctuation spectra obtained by passing a current through the samples. These measurements contribute strong evidence that 1/f ...

This report presents results of a series of site and noise surveys performed in Alaska. Surveys were performed at the former OTH-B site at Gulkana with the aim of determining the spectrum occupancy and background noise level at nominally 38 MHz, 420 MHz, and 440 MHz. Three site surveys were performed at Elmendorf AFB near Anchorage, aimed at determining ...

Johnson noise power measuring techniques have been used to calibrate platinum resistance temperature detectors (RTDs) installed in an operating nuclear plant - Connecticut Yankee Atomic Power Company's Haddam Neck Nuclear Plant - achieving agreement with the dc calibration from better than 0.1% to as much as 1% (0.54 to 9.7/sup 0/F) at the normal ...

Predictions of the prevalence of annoyance associated with aircraft noise exposure are heavily influenced by field studies conducted in urban airport neighborhoods. Flyovers heard in such relatively high ambient noise environments are composed in large part of high absolute level, broadband noise. In contrast, ...

A new high-level noise source was developed specifically for the calibration of Johnson noise power thermometers (JNPT), but it is useful in other applications requiring a stable, wideband, well-defined noise power spectral density. The design concept for the noise source is based on the fact ...

A stochastic control problem is obtained as a small noise approximation to a deterministic optimal control problem. Two classes of admissible controls are considered and the optimal control policies are explicitly determined for a each admissible class. T...

Work over the past year on testing and improvement of the multiwire proportional chamber is reviewed. Accomplishments include a reduced absolute noise level, a study on the counting rate, measurement of resolution, improved preamplifier performance, acqui...

Contents: The quartz-steel sandwich, Research climate at NRL, Synthetic crystals, Development of sound-transparent rubber windows, Magnetostrictivetransducers, Absolute acoustic standards in liquids, Electrodynamic transducer, The self-noise problem, A un...

A reactivity measurement method (the NTFODRS) was experimentally verified on the University of New Mexico (UNM) AGN-201M thermal reactor to obtain the absolute steady-state reactivity and demonstrate the feasibility of acquiring the transient reactivity. ...

Dicke radiometer, noise injection radiometer and total power radiometers used in remote sensing are described. The achievable temperature resolution and the absolute accuracy of the brightness temperature measurement are discussed. A remote sensing radiom...

Microwave radiometry is the spectral measurement technique of resolving electromagnetic radiation of all matters which temperature is above absolute zero. This technique utilized the electromagnetic noise field generated by a thermal volume similar to a m...

A dual-channel low-noise heterodyne receiver is presented as part of a development effort to build a carbon dioxide laser-based Thomson scattering alpha particle diagnostic for a burning plasma experiment./aip/

Feb 14, 2006 ... The thermometer readout and thermal control system for the Absolute ... mK in a second for the RuO2 resistive thermometers at 2.7 K. The ...

This paper describes a threshold track-and-hold device for determining the event time of the absolute maximum in a realiaztion of a stochastic process of finite duration. The range of input signal levels is + or - 3 V, and the upper frequency limit is greater than or equal to500 kHz. The absolute measurement error does not exceed 500 nsec. for an input ...

A method for absolute calibration of proportional counters for pulsed fast neutrons is presented. The method is based on the use of an isotopic standard source and development of a model for counting detected events from area of a signal compounded by single piled up neutron pulses. Effects of detection counting statistics and electrical background noise ...

A method for absolute calibration of proportional counters for pulsed fast neutrons is presented. The method is based on the use of an isotopic standard source and development of a model for counting detected events from area of a signal compounded by single piled up neutron pulses. Effects of detection counting statistics and electrical background noise ...

Experimental evidence of convective and absolute instabilities in a nonlinear optical system is given. In optics, the presence of spatial nonuniformities brings in additional complexity. Hence, signatures characterizing these two regimes are derived based on analytical and numerical investigations. The corresponding noise-sustained and dynamical patterns ...

We propose and demonstrate experimentally a new method based on the spatial entanglement for the absolute calibration of analog detectors. The idea consists on measuring the sub-shot-noise intensity correlation between two branches of parametric down conversion, containing many pairwise correlated spatial modes. We calibrate a scientific CCD camera and a ...

We present an optical frequency divider based on a 200?MHz repetition rate Er:fiber mode-locked laser that, when locked to a stable optical frequency reference, generates microwave signals with absolute phase noise that is equal to or better than cryogenic microwave oscillators. At 1?Hz offset from a 10?GHz carrier, the phase noise is ...

In this paper a new filter for image sequences corrupted with random impulse noise is presented. In order to preserve the image details as much as possible, the noise is removed in different successive filtering steps. In each step, only the pixels that are detected as being noisy are filtered, while the noise-free pixels remain ...

Abstract. Context-awareness is essential to the development of adaptive information systems. Much work has been done on developing technologies and systems that are aware of absolute location in space and time; other aspects of context have been relatively neglected. We describe our approach to automatically sensing and recognising environmental noise as a ...

In this paper, a new fuzzy filter for the removal of random impulse noise in color video is presented. By working with different successive filtering steps, a very good tradeoff between detail preservation and noise removal is obtained. One strong filtering step that should remove all noise at once would inevitably also remove a ...

Johnson noise power measuring techniques have been used to calibrate platinum resistance temperature detectors (RTDs) installed in an operating nuclear plant - Connecticut Yankee Atomic Power Company's Haddam Neck Nuclear Plant - achieving agreement with ...

... no. 2, 1 Dec 78-31 Mar 79,. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CALIF. Personal Author(s) : Clark,Douglas B. ; Rettig,John B. ...

Back to I, Forward to K jabber jacket jamming margin jamming to signal ratio (J/S) jam signal jerkiness jitter job job-recovery control file Johnson noise joint joint multichannel...

Contents: Welcome; Quantum Standards; Quantum Voltage; Johnson Noise Thermometry; Single Electronics for Standards and Metrology; Physics of Quantum Hall Resistance Standards; Quantum Information; Quantum Computing; Quantum Communication; Quantum Measurem...

... no. 7, 1 Jun-31 Dec 1962. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CA. Personal Author(s) : Kinaman, EW. Handle / proxy Url : ...

... Descriptive Note : Final rept. 1 Dec 60-31 Dec 63,. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CA. Personal Author(s) : Kinaman, EW. ...

... 1 Mar-1 Sep 66. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CA. Personal Author(s) : Frost, Robert D. ; Mauch, Fred T. ...

CSC/Houston/M30/E. Brownd. R. Khare. G. Johnson. B. Schumacher ...... Upon the initiation of search, the radar performs automatic search about a direc ...... At low levels the airborne and ground thermal noise become the largest. ...

Apr 21, 2011 ... Hearing tests, called pure-tone air conduction audiometry, were conducted under standard conditions at the health clinic at NASA's Johnson ...

... 1 Jan-15 Sep 67,. Corporate Author : WATKINS-JOHNSON CO PALO ALTO CA. Personal Author(s) : Kinaman, EW. Report Date : DEC 1967. ...

In this paper, the direct detection behaviors of a superconducting hot electron bolometer integrated with a log spiral antenna are investigated by using Fourier Transform Spectrometer (FTS). We find the response of the bolometer to a modulated signal can be detected by a lock-in amplifier not only from the DC bias current, but also from the output noise power at the IF port of ...

Circuits, parts lists, and fabrication and test instructions are furnished for a packaged Johnson noise power thermometer sensor probe and readout system suitable for measurements of temperatures from 273 to 1000 K (0 to 727/sup 0/C) with an accuracy of better than 0.5% (one count on the digital display). The sensor is an 18-in.-long, 0.118-in. OD, ...

Abstract: We present a comprehensive analysis of the Johnson (like) noise based classical key-distribution scheme presented by Kish [1]. We suggest two passive attack strategies that enable an adversary to gain complete knowledge of the exchanged key. The first approach exploits the transient response of the voltage in the transmission line after the ...

A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The ...

A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The ...

The systematic measurement of shot noise allows one to directly measure the transmittance of individual conductance modes, and can lead to useful inferences on the nature of quantum transport in various materials. At low temperatures (4.2 K) the contribution of heating-induced Johnson noise is reduced significantly; however, ...

In order to improve the noise immunity and increase the availability of the DIII-D ECE radiometer, the radiometer receiver will be located outside the radiation shield wall. Further noise immunity is obtained by the use of a 50 kHz rf modulator, which is compatible with the 90 to 140 GHz low loss, single mode transmission system, the design and expected ...

A design method for Active Noise Control (ANC) systems operating in a three dimensional nondispersive propagation medium is presented. The method is based on analysis of the relative stability of the inherent feedback loop. For practical systems, the use of absolute stability is not useful. A system having an extremely long oscillatory response is unlikely ...

Methods for inferring absolute velocity from hydrographic observations recently advanced by Stommel and Schott and by Wunsch are compared and found to be based on equivalent dynamical sophistication. The differences in the methods are shown to result from differing assumptions about the scales of the quasi-steadylarge-scale signal and the variability or ...

Hearing-impaired (HI) listeners often show poorer performance on psychoacoustic tasks than do normal-hearing (NH) listeners. Although some such deficits may reflect changes in suprathreshold sound processing, others may be due to stimulus audibility and the elevated absolute thresholds associated with hearing loss. Masking noise can be used to raise the ...

High permeability magnetic shields often generate magnetic field noise that can limit the sensitivity of precision measurements. We show that calculations based on the fluctuation-dissipation theorem allow evaluation of magnetic field noise, either by current or spin fluctuations, from high permeability metals and ferrites over a broad frequency range. For ...

The helical magnetorotational instability of the magnetized Taylor-Couette flow is studied numerically in a finite cylinder. A distant upstream insulating boundary is shown to stabilize the convective instability entirely while reducing the growth rate of the absolute instability. The reduction is less severe with larger height. After modeling the boundary conditions properly, ...

The helical magnetorotational instability of the magnetized Taylor-Couette flow is studied numerically in a finite cylinder. A distant upstream insulating boundary is shown to stabilize the convective instability entirely while reducing the growth rate of the absolute instability. The reduction is less severe with larger height. After modeling the boundary conditions properly, ...

We describe techniques and an experimental setup to measure the gain and noise characteristics of a long-range surface plasmon-polariton amplifier consisting of a symmetric metallic stripe waveguide incorporating optically pumped dye molecules in the solution as the gain medium. The setup is capable of acquiring absolute power measurements at the ...

We describe techniques and an experimental setup to measure the gain and noise characteristics of a long-range surface plasmon-polariton amplifier consisting of a symmetric metallic stripe waveguide incorporating optically pumped dye molecules in the solution as the gain medium. The setup is capable of acquiring absolute power measurements at the ...

We obtain a heterodyne beat signal between an iodine-stabilized He-Ne laser at 633 nm and a low power comb mode of an optical frequency synthesizer with an enhanced signal-to-noise ratio (SNR) up to{approx}35 dB. This is accomplished by the adoption of a fiber coupler and the reduction of the shot noise induced by adjacent comb modes. SNR is improved more ...

This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) ...

The absolute force sensitivities of colloidal probes comprised of atomic force microscope, or AFM, cantilevers with microspheres attached to their distal ends are measured. The force sensitivities are calibrated through reference to accurate electrostatic forces, the realizations of which are described in detail. Furthermore, the absolute accuracy of a ...

A Green's function approach is developed from first principles to evaluate the power spectral density of conductance fluctuations caused by ion concentration fluctuations via diffusion in an electrolyte system. This is applied to simple geometric models of transmembrane ion channels to obtain an estimate of the magnitude of ion concentration fluctuation noise in the channel ...

Using a simple lumped-circuit model, we numerically study the dependence of the voltage gain and noise on the amplifier's parameters. Linear, quasi-linear, and nonlinear regimes are studied. We have shown that the voltage gain of the amplifier cannot exceed a characteristic critical value, which decreases with the increase of the input power. We have also shown that the ...

Fourteen individuals who stutter and 14 nonstuttering individuals were assessed for the magnitude of their eye blink responses to noise bursts as a measure of temperament. Eye blink response to the initial noise burst and the mean of 10 responses were significantly greater for the stuttering group. Additionally, the Nervous subscale of the ...

on nanofabricated junctions.2 This is partly due to the dual role that the current amplifier has to play in the STM is connected to the virtual ground in- put of the room temperature current amplifier see, e.g., Refs. 4 and 5 CURRENT AMPLIFIER A major source of noise in the LT circuit is Johnson noise in the measurement resistor

De-noising algorithms based on wavelet thresholding replace small wavelet coefficients by zero and keep or shrink the coefficients with absolute value above the threshold. The optimal threshold minimizes the error of the result as compared to the unknown, exact data. To estimate this optimal threshold, we use Generalized Cross Validation. This procedure is ...

We report a semiconductor-based, low-noise, 10.24 GHz actively mode-locked laser with 4.65 fs of relative timing jitter and a 0.0365% amplitude fluctuation (1 Hz to 100 MHz) of the optical pulse train. The keys to obtaining this result were the laser's high optical power and the low phase noise of the rf source used to mode lock the laser. The low phase ...

Noise, or random fluctuations, in gene expression may produce variability in cellular behavior. To measure the noise intrinsic to eukaryotic gene expression, we quantified the differences in expression of two alleles in a diploid cell. We found that such noise is gene-specific and not dependent on the regulatory pathway or ...

Overdamped motion of Brownian particles in a 1D periodic system with a simple symmetric sawtooth potential subjected to both unbiased thermal noise and spatially nonhomogeneous three-level colored noise is considered analytically. Upon application of a tilting force the particles exhibit anomalous transport properties, namely, absolute ...

Cost effective methods for identifying and reducing sources of noise have become essential in the design of many modern transport vehicles. Whilst closed-section wind tunnels can readily evaluate aerodynamic performance, obtaining accurate acoustic spectra is often a major challenge because of the poor signal to noise ratios available. In this paper, ...

The variance of temperature measurements made with the NIST Johnson noise thermometer has been reduced by the use of improved cross-correlation electronics and a unique method for measuring and reducing non-linearities. The spectral response of the voltage noise and the reproducibility of the measured temperature were improved by the ...

A comprehensive account of the theory of the singly quasidegenerate Josephson junction parametric amplifier is given. In this mode the signal and idler frequencies are both approximately equal to half the pump frequency, and hence the signal and idler channels have a common termination. It is shown that the performance of the amplifier characterized by properties such as gain-bandwidth product, ...

Rhenium ultrasonic (UST) and Johnson noise (JNT) thermometers were used to measure fuel centerline temperatures of 900--1500$sup 0$C in capsules irradiated in the HFIR for periods of 1000--3000 hrs. Transmutation of rhenium by thermal neutron absorption caused large drifts in UST calibration but none in JNT calibration. Whole capsule, post ...

The Boltzmann constant k was measured by comparing the Johnson noise of a resistor at the triple point of water with a quantum-based voltage reference signal generated with a superconducting Josephson-junction waveform synthesizer. The measured value of k = 1.380 651(17) � 10?23 J K?1 is consistent with the current CODATA value and the combined ...

A primary difference between terrestrial and remotely located reactors is the ability to periodically recalibrate and replace the instrumentation. Because of this, space reactors place a premium on self-calibrating, long-term reliable instrumentation. The primary temperature measurements for the SP-100 reactor were to be made using W/W-Re thermocouples. However, the large gamma and neutron dose ...

A prototype of SQUID read-out for current measurements at the output of a normal metal hot-electron microbolometer has been developed and tested. The system is based on serial VTT dc SQUID and input /?-metal core solenoid transformer. The achieved current resolution is 300 fA/Hz1/2. Johnson noise of metal resistor and shot noise of ...

A noise power thermometer for temperature measurements to 2200 C in reactor fuel rods was fabricated and tested for use in the loss of fluid test reactor safety tests. Temperature is determined by measuring the thermal noise spontaneously generated in a sensor coil. Thermoelement wires are used for connecting leads to the sensor coil and thereby provide ...

A high-temperature superconducting-receiver system for use in nuclear magnetic resonance (NMR) microscopy is described. The scaling behavior of sources of sample and receiver-coil noise is analyzed, and it is demonstrated that Johnson, or thermal, noise in the receiver coil is the factor that limits resolution. The behavior of ...

Noise exposure can affect the functioning of inner hair cells (IHC) within the cochlea, leading to a 'noisy' representation of the properties of sounds even when absolute thresholds are normal. This may lead to a reduced ability to discriminate sounds based on their statistical properties, especially for narrowband sounds presented at low levels, since ...

To observe secular land movements of the order of a few millimetres per year, a very precise instrument with long-term stability is required. This can be achieved using absolute gravimeters, which do not depend on a reference frame. Vertical land movements would modify the gravity at a rate of about -10 nms-2 (1 ? Gal) for 5 mm of uplift. Repeated absolute ...

Magnetoresistance and voltage noise measurements are report in three magnetoresistive systems: nonstoichiometric silver chalcogenides, zigzag-shaped permalloy elements, and magnetic tunnel junctions. The nonstoichiometric silver chalcogenides are attractive for studying the mechanisms of linear magnetoresistance and for magnetic field sensing applications. Low-frequency ...

Evaluation of the inherent noise levels of high-responsivity sensors is critical for good design but this area is often treated casually until testing reveals a problem. Careful noise analysis early in the design process can save time, effort, and much frustration and reveal options for better performance. Once the sensor is fabricated, careful measurement ...

Microwave amplifiers, based on washer-type niobium dc SQUIDs with integrated input coils that act as a microstrip resonator operate at frequencies between 50 MHz and 2 GHz, and in principle are capable of reaching the Standard Quantum Limit (SQL) for linear amplifiers. In practice, heating of the shunt resistors may increase their Johnson noise thereby ...