A double coil method for simultaneously measuring the resistivity,permeability, and thickness of a moving metal sheet

A method to determine the resistivity, permeability and thickness of moving magnetic sheets is described. The parameters of a sample sheet inserted between two coils facing each other are determined by measuring the impedance of the two coils at two different frequencies. To compare the experimental data with theoretical values, the difference in the impedance of the coils between two cases is used: when the current passes through the coils in the same direction, and in opposite directions. The method was tested by measuring the resistivity, permeability and thickness of nickel and iron sheets, 1 mm thick, moving at velocities varying from 0 to 6 m/s. It was possible to accurately determine the resistivity, thickness, and permeability within 10%, 10%, and 20%, respectively, at frequencies of 400 and 800 Hz     

Simultaneous measurement of resistivity and temperature coefficient of resistivity of metallic thin films with the transient hot-strip method

The recently described transient hot-strip method for measuring thermal transport properties of solid insulators has been developed for simultaneously measuring the resistivity ?_F and the temperature coefficient of resistivity (TCR) α_F of metallic thin films. The experimental arrangement is similar to the well-known four-probe technique but the constant current pulse passed through the thin film is sufficiently high to increase its mean temperature by about 1 K. By measuring the time-varying increase or decrease in the resistance, information is obtained not only about the resistivity but also about the TCR.The main advantage of the method is the possibility to measure ?_F and α_F simultaneously without increasing or decreasing the temperature of the film by more than 1 K, i.e. without measurably changing the properties of the film.The method has been tested on unannealed copper films at room temperature.     

Simultaneous measurement of electric and magnetic properties of aspherical sample

A method using a solenoid coil for simultaneously estimating the electric and magnetic properties of a spherical conductor was studied. These properties are estimated by finding the difference in the complex impedance of the coil with and without a sample to find out the measuring value that best coincides with the theoretical value. A new formula applicable to a nonmagnetic, a magnetic or a superconductive spherical sample was derived. The conductivities a and permeabilities μ measured by this method and by the conventional methods were compared using various samples. The deviations were no larger than 3% for a nonmagnetic samples, and 1.5% for μ of magnetic samples     

A method for simultaneously measuring resistivity and permeabilitywith a multilayer solenoid coil

A formula is given for a more accurate estimate of either the resistivity and permeability of a cylindrical magnetic material or the resistivity and penetration depth of a cylindrical superconductor, using the difference in the complex impedance between a circular multilayer solenoid coil having a conductor and a similar coil without a conductor. In comparison with the conventional method which uses a single-layer solenoid coil, it is shown experimentally that a multilayer solenoid coil is more effective for a short sample conductor because a larger difference in the complex impedance is obtained without increasing the width of the solenoid coil. The results of measurements of magnetic and superconductive materials are included     

Simultaneous measurement of one- and two-photon excited fluorescence from a single sample: a detection method for oligonucleotides

A new method has been developed that is based on the use of a single-excitation wavelength from a cw laser to excite simultaneously one-photon and two-photon fluorescence (TPF). Fluorescence bands of a sample containing two oligonucleotides, one labeled with a one-photon fluorescence dye and the other with a TPF dye, can be measured simultaneously. The two fluorescence bands are well separated, because the one-photon excited fluorescence band is redshifted, whereas the TPF band is blueshifted from the excitation wavelength. The spectral separation was found to be as large as 200 nm when ADS 840NCS was used to label one oligonucleotide for one-photon fluorescence and Rhodamine Red-X dye was used for TPF. Spectral overlapping problem that plagues current DNA sequencing techniques can be eliminated effectively with this method.     

Expanding the measurement of culture with a sample of two billion humans

Culture has played a pivotal role in human evolution. Yet, the ability of social scientists to study culture is limited by the currently available measurement instruments. Scholars of culture must regularly choose between scalable but sparse survey-based methods or restricted but rich ethnographic methods. Here, we demonstrate that massive online social networks can advance the study of human culture by providing quantitative, scalable and high-resolution measurement of behaviourally revealed cultural values and preferences. We employ data across nearly 60 000 topic dimensions drawn from two billion Facebook users across 225 countries and territories. We first validate that cultural distances calculated from this measurement instrument correspond to traditional survey-based and objective measures of cross-national cultural differences. We then demonstrate that this expanded measure enables rich insight into the cultural landscape globally at previously impossible resolution. We analyse the importance of national borders in shaping culture and compare subnational divisiveness with gender divisiveness across countries. Our measure enables detailed investigation into the geopolitical stability of countries, social cleavages within small- and large-scale human groups, the integration of migrant populations and the disaffection of certain population groups from the political process, among myriad other potential future applications.     

Calculation of the difference in impedance for a solenoid coil withand without a sample conductor

Either the resistivity and permeability of a magnetic material or the resistivity and magnetic penetration depth of a superconductor can be simultaneously estimated from the difference in the complex impedance between a circular solenoid coil coaxially surrounding a cylindrical conductor and an identical coil without a sample conductor. A method for calculating the difference in the complex impedance at a high frequency including the displacement current to an accuracy of 0.1% is reported. Comparison of the values calculated by this method and the values obtained by a conventional method which does not include the term of displacement current is also included     

Measuring the temperature dependence of resistivity of high puritycopper using a solenoid coil (SRPM method)

The resistivity of high purity copper was measured by a method which estimates it by using the difference in the impedance between a circular multilayer solenoid coil with a circular rod-shaped copper sample and a similar coil without a copper sample (SRPM method). The residual resistivity ratio (RRR) of high purity copper measured at 100 Hz by the SRPM method has correlated well with the values measured by the DC four-probe method. It was confirmed that an accurate measurement of the resistivity to 10^-12 Ωm is possible by the SRPM method. Frequency dependence was confirmed to exist in high purity copper with very low resistivity. As the measuring frequency is raised, the decrease in skin depth seems to affect the resistivity     

生物微胶囊渗透分离特性的表征和测定

渗透分离特性是生物微胶囊的重要性能指标之一，它决定了制备的微胶整是否适用于临床应用或细胞培养。以目前应用最多的，最具生物相容性的海藻酸钠－聚赖氨酸－海藻酸钠（简称ＡＰＡ）生物微胶囊为例，综合膜分离技术中表示超滤、微滤和透析膜分离透过特性的物化参数，结合微胶囊自身特点，建立较为全面地表征微胶囊渗透分离特性的系统和方法，为生物微胶囊的研究奠定了理论基础。     

Compression flow permeability measurement: a continuous technique

Existing permeability measurement techniques are based upon pressure driven flow through fibrous reinforcing materials. An innovative method is presented here utilising compression driven flow, which allows for continuous measurement of permeability over wide fibre volume fraction ranges, in a single efficient test. The initial study has been limited to isotropic reinforcements, obtained permeability data being compared with values measured using a more conventional method. Data has been collected from two styles of random mat, volume fraction varied from 20 to 50% in each test. Comparison between the two methods is very promising, validating further study and extension of this new technique. Larger errors have been noted at higher volume fractions, this effect being related to increasing mold clamping forces, and a subsequent translational deflection of the upper platen.     

High frequency magnetic properties and intergranule interaction of nano-granular films with high resistivity and high permeability

In order to get magnetic films with high permeability and high resistivity for applications in high frequency devices, (Fe65Co35)x(SiO2)1-x nano-granular films with low metal volume fraction were fabricated by radio frequency magnetron sputtering, and excellent soft magnetic properties have been acquired by annealing the sample with x = 0.38 at 260 degrees C in a magnetic field. The real part micro' of complex permeability is larger than 100 when frequency f is lower than 0.7 GHz, and the ferromagnetic resonance frequency f(r) is as high as 1.8 GHz. More interestedly, the resistivity of this sample reaches 13.4 momega x cm, 4 orders higher than that of pure FeCo alloy. Ferromagnetic resonance experiment and deltam-H curve study were employed to elucidate the mechanism of soft magnetic properties. The results reveal that the intergranule exchange coupling plays an important role in realizing good soft magnetic properties for metal-insulator granular films.     

Direct measurement of the transverse resistivity of multifilamentary superconducting composites

A method which measures directly transvere resistivity in multifilamentary superconducting composites has been developed. Measurements of the composites having filaments of NbTi-50 alloy (Nb - 50% weight Ti) embedded in a copper matrix have been carried out at 4.2 K, 12 K, and 300 K in a field of up to 6 T. Using the obtained values of the effective transverse resistivity ρ_⊥, the calculation of the eddy current losses has been performed. These losses are compared with the experimental values measured by a calorimetric method.     

Simultaneous three-dimensional step-height measurement and high-resolution tomographic imaging with a spectral interferometric microscope

A noncontact, nonmechanical scanning, wide-field spectral interference microscope is developed for simultaneous measurement of three-dimensional step-height of discontinuous objects and tomographic imaging. A superluminescent diode (SLD) is used as a broadband light source and a liquid-crystal Fabry-Perot interferometer (LC-FPI) as a frequency-scanning device. By means of changing the injection current to the SLD, the spectral profile of the SLD is equalized, and a constant light input to the interferometer is achieved over the entire frequency-scan range. The Fourier-transform technique is used to determine both the amplitude and the phase of spectral fringe signals. Three-dimensional height distribution of a discontinuous object is obtained from the phase information, whereas optically sectioned images of the object are obtained either from the amplitude information alone or from the combination of both the amplitude and phase information. Experimental results with submicrometer resolution are presented for both step-height measurement and tomographic sectioning.     

Simultaneous measurement of temperature and pressure

It is shown theoretically and experimentally that nuclear quadrupole resonance can be used to measure temperature and pressure simultaneously. Pis’ma Zh. Tekh. Fiz. 24, 54–57 (January 26, 1998)     

Method of electrical resistivity measurement for high-temperature melts

A contactless method of electrical resistivity measurement for high-temperature melts is described. The method is based on induction melting in split water-cooled crucible and solving the inverse problem of electromagnetic field with the use of the thermal and electrical parameters of an induction system. Results of the electrical resistivity measurement of a pure-grade aluminum oxide melt within the temperature range of 2300–2950°C in air are presented.     

Simultaneous measurement of temperature and chemical species concentrations with a holographic interferometer and infrared absorption

What is believed to be a new technique that allows for the simultaneous measurement of 2D temperature and chemical species concentration profiles with high spatial resolution and fast time response was developed and tested successfully by measuring a thin layer of fuel vapor created over a volatile fuel surface. Normal propanol was placed in an open-top rectangular container, and n-propanol fuel vapor was formed over the propanol surface in a quiescent laboratory environment. An IR beam with a wavelength of 8-13 mum emitted from a heated plate and a He-Ne laser beam with a wavelength of 632 nm were combined and passed through the n-propanol vapor layer, and both beams were absorbed by the vapor layer. The absorption of the IR beam was recorded by an IR camera, and the He-Ne laser was used to form a holographic interferogram. Two-dimensional temperature and propanol vapor concentration profiles were, respectively, determined by the IR absorption and the fringe pattern associated with the holographic interferogram. This new measurement technique is a significant improvement over the dual wavelength holographic interferometry that has been used previously to measure temperature and fuel concentration, and it is ready for application under different types of fire and flame conditions.     

Simultaneous measurement of multiparameters using a Sagnac interferometer with polarization maintaining side-hole fiber

A Sagnac interferometer with a section of a polarization maintaining side-hole fiber for multiparameter measurement is proposed. The sensor was experimentally demonstrated to be sensitive to torsion, temperature, and longitudinal strain, simultaneously. The birefringence in the investigated side-hole fiber is induced simultaneously by the elliptical shape of a germanium-doped core and by field overlap with the air holes surrounding the core. The latter effect is purely geometrical and causes high chromatic dispersion of the group birefringence in the long wavelength range, which results in a different period of spectral interference fringes. A different wavelength response is obtained for each interference fringe peak when the fiber is subjected to torsion, temperature, or longitudinal strain. A matrix equation for simultaneous measurement of the three parameters--torsion, temperature, and longitudinal strain--is also proposed.