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This paper reports on work conducted to investigate the effect that electrical discharge machining (EDM) notch width has on the eddy current (EC) signal as a function of coil drive frequency. The notch results are also compared to EC signals from laboratory‐grown fatigue cracks. This study builds upon previous work with titanium, Inconel and aluminum materials where the signal amplitude was shown to decrease, as expected, as the notch width decreases. The trend was captured well by numerical results and this allowed estimates to be made about the signals from idealized “zero‐width” notches. The results indicated that the signal reduction factor from a 0.127 mm (0.005 inch) wide, rectangular notch to a theoretical zero‐width semi‐elliptical notch of the same size ranged from 25 to 42% for low conductivity materials when data was collected at 2 MHz. For aluminum, the difference between signals from 0.127 mm wide notches and estimated signals for zero‐width notches was approximately 50%. However, 2 MHz is an uncommonly high frequency for inspecting aluminum alloys so additional work was necessary to investigate the notch width effect at lower frequencies. This study sought to determine how the notch‐width effect changed as a function of frequency for high conductivity materials such as aluminum.

This paper reports on a type of multiple frequency eddy current NDE methodologies. A specific focus was placed on a multiple low frequency methodology that is suitable for case depth characterization of case‐hardened steel samples. A nominally uniform excitation field approach has been developed, and demonstrated to work for discriminating the case depths ranging between 1 mm and 6 mm, while meeting additional requirements of one‐sided access and a finite stand‐off distance.

We have measured the cross section for γγ production with the TOPAZ detector in the energy region √ s =50.0–61.4 GeV. The observed cross section for γγ production integrated over |cos θ | ⩽ 0.77 is 50.2±0.8±2.2 pb at 〈√ s 〉=57.6 GeV and the ratio of this value to the QED prediction is 1.01±0.02±0.04. The angular distribution is in good agreement with the QED predictions, thereby setting limits on the compositeness scales, Λ L+R + =168 GeV, Λ L+R − =97 GeV, Λ L,R =141 GeV, Λ L,R − =81 GeV, and Λ L−R ± =68 GeV, at the 95% confidence level. The reaction e + e − → γγγ was also studied and was found consistent with the QED prediction.

The process e + e − →e + e − μ + μ − has been studied in single-tag and double-tag configurations using the TOPAZ detector at TRISTAN. The data correspond to the integrated luminosity of 45.3pb − at center-of-mass energies ranging from 52 to 61.4 GeV. The observed events in both configurations have shown a good agreement with QED predictions in order α 4 . Although the AMY group reported an excess of e + e − →e + e − μ + μ − events in double-tag mode at low muon invariant mass region less than 1.0 GeV/c 2 , we did not observed such excess in our data.

An experimental study of b-quark jets using high-pT electrons was carried out at √s=58 GeV with the TOPAZ detector at the e+e− collider TRISTAN at KEK. The forward-backward charge asymmetry of the b-quark was obtained to be A b b =−0.55±0.27( stat. )±0.07( syst. ) , consistent with the standard model prediction. Also, such jet properties of the b-quark as the average charged multiplicity and the rapidity of charged particles were analyzed. In order to purify the b-quark event samples in this analysis, only events with backward-going electrons or forward-going positrons were used. The energy dependence of these jet properties was studied by making comparisons with the results of the DELCO experiment at the PEP collider (√s=29 GeV) at SLAC.

We investigated the in vivo antagonistic activity of ONO-1078 against peptide leukotrienes (LTs) in guinea pigs. ONO-1078, when administered p.o. (0.3-3 mg/kg), caused a dose-dependent reduction of LTC4-, LTD4- and LTE4-induced bronchoconstriction, LTD4-induced airway microvascular leakage and LTD4-induced increase in cutaneous vascular permeability. When administered intravenously, ONO-1078 (3-30 micrograms/kg) inhibited these responses approximately 200-600 fold more potently than FPL55712. When guinea pigs were treated with indomethacin to examine the antagonism of ONO-1078 on the direct action against peptide LTs, intravenous (3-30 micrograms/kg) and oral (0.3-3 mg/kg) administration of ONO-1078 also inhibited LTC4- and LTD4-induced bronchoconstriction, and its activity was approximately 300-500 fold more potent than that of FPL55712. ONO-1078 (10 mg/kg, i.v.) had no inhibitory effect on bronchoconstrictions induced by histamine, acetylcholine, serotonin, arachidonic acid, LTB4, prostaglandin (PG) F2 alpha, PGD2, 9 alpha, 11 beta-PGF2, a stable thromboxane A2 mimetic agent and platelet activating factor. Furthermore, oral administration of ONO-1078 (1-10 mg/kg) inhibited slow-reacting substance of anaphylaxis mediated bronchoconstriction induced by antigen in a dose-dependent manner. These results indicate that ONO-1078 is an extremely potent, selective and orally active peptide LT antagonist and that oral administration of ONO-1078 antagonizes not only exogenously administered peptide LTs but also endogenous peptide LTs.

We present a grating-pair-formed pulse shaper with a spatial light modulator (SLM) for programmable chirp compensation by applying voltages on the SLM. When linear and nonlinear chirp are optimally compensated for, corresponding to the quadratic, cubic, and quartic phases of -400 fs/sup 2/, 1100 fs/sup 3/, and 2000 fs/sup 4/ at the center wavelength 780 nm on the SLM, a stronger chirped white light continuum (WLC) pulse with a spectral bandwidth of 570-970 nm is compressed to the sub-6-fs regime.

We carried out feedback chirp compensation using a two-dimension spatial light modulator operating in a wavelength range from 260 to 1100 nm, which is useful for the application to ultrabroadband and high-powered optical pulses.

We report on progress in a swept high frequency eddy current (SHFEC) technique for characterization of surface residual stress on shot‐peened superalloy surfaces. Our aim here is to demonstrate the sensitivity of our measurement for practical shot peening intensities, i.e. at 4∼6 A. First, we present our improved probe and instrumentation being sufficiently sensitive to resolve the surface conditions at these low Almen intensities, where our earlier measurements encountered noise problems. The previous coil was also larger (18 mm in diameter) than desirable. Our new probe integrates smaller coils (12 mm in diameter, forming an AC bridge) and on‐board electronics on a common printed circuit board, mutually connected at the shortest possible distance. The operational‐amplifier‐based electronics acts as impedance buffers, and maintains the cabling impedance at the characteristic 50 Ω between the probe board and the instruments. We have thus reduced the instrumentation noises. Second, we present the result of...

A sometimes stated rule of thumb is that the eddy current signal from a fatigue crack can be 60% of the strength produced by a similarly sized, rectangular EDM notch. A study was conducted to explore the effect that the width of a discontinuity has on signal strength when inspecting low conductivity materials for small cracks with eddy current surface probes. EDM notches of different sizes and shapes were planted in Ti‐6246 and IN‐100 specimens. Each of the two materials received six 0.020 inch long by 0.010 inch deep notches and six 0.030 inch and 0.015 inch deep notches. Three of the notches of each size were rectangular shaped and three were semicircular shaped. One of the notches in each material size group was 0.005 inch wide, one was 0.003 inch wide and one was 0.001 inch wide. Each of the notches was scanned using absolute and differential pencil probes driven at several different frequencies. The experimental results were compared with numerically generated results, which allowed for a zero width notch to be considered. The results indicated that the signal reduction factor from a 0.005 inch wide, rectangular notch to a theoretical zero‐width notch of the same size ranged from 25 to 42%.

Shot peening is frequently used to improve mechanical characteristics of metallic components’ surfaces. The physical properties of shot peened surfaces exhibit deviations from their bulk values. This paper shows that there exists a scaling law (universality) among seemingly unrelated material property deviations and among different peening conditions. We present examples and support for scaling behaviors based on experimental data on Almen strip deflection, cold work and residual stress profiles of a shot peened nickel‐base superalloy (Waspaloy), and swept frequency eddy current signals used for NDE studies of another shot peened nickel‐base superalloy (Inconel 718). In addition, a fast impedance calculation formula for a coil placed on a metal with small, continuous conductivity deviation is presented and used for analytical and numerical study of eddy current signals.

This paper reports on a self‐consistent, swept frequency eddy current (SFEC) technique for characterizing surface and sub‐surface conditions of materials, with specific applications to detecting residual stresses in shot‐peened Ni‐base superalloys and surface oxidation in engineering components. The technique involves measuring lift‐off normalized vertical component signal to suppress lift off noise and instrumentation effect. Theoretical study shows that the vertical component signals are insensitive to coil dimensions, thus enabling EC measurements in separate frequency bands using multiple coils, while yielding continuous broad‐band data so that both the bulk conductivity and near‐surface conductivity profile can be determined by model‐based inversion. We demonstrate the technique on two surface‐modified materials, namely Inconel 718 samples shot peened at 4 A to 8 A, and an Ag‐1.5at%Al alloy which was used as a model material for a fundamental study of internal oxidation. For each sample set, the vertical component signals measured using two dissimilar sets of coils and instruments were found to overlap, confirming that the signals are insensitive to coil dimensions and instrumentation. The bulk conductivities of the samples were determined by inverting the low frequency data. The results were then used to constrain model‐based inversion of the high frequency data to obtain near‐surface conductivity profiles, from which the residual stress profile of the shot‐peened Inconel 718 and the oxidization depth of the Ag‐Al alloy can be inferred.

This paper reports on a study of the effects of dynamic and static loading on eddy current (EC) crack signals in aerospace materials. In situ EC measurements were performed on a series of fatigue crack samples grown in Al 6061 bars under dynamic loading. The EC signals detected at a fixed location on the fatigue cracks were found to vary periodically with cyclic loading. Under dynamic tension, the amplitude of the vertical component of the crack signal, which is perpendicular to the lift off direction, increases with the load amplitude and the effect is stronger for longer cracks. Such changes in EC signals are attributable to crack morphology changes (i.e. crack opening) under tension. In contrast, the amplitude of crack signal remains relatively unchanged under compression, possibly due to the insulation effect of the oxidation layer on the crack face. The loading effects on crack signals in the Al samples were confirmed by obtaining c‐scan images of the fatigue cracks under static loads. C‐scans conducted on a series of Ti 64 fatigue crack samples under static loads revealed significantly stronger stress‐induced changes of crack signal for Ti 64 than for the Al samples. The results are interpreted in terms of load‐induced crack morphology changes, taking into account of likely differences between the Al and Ti alloy samples.

We have collected 122 multi-hadronic inclusive muon events with the TOPAZ detector at 〈s〉 = 58.27 GeV with ∫Ldt=40.61 pb−1. From this event sample we derived the differential cross section for B-hadron productions and determined B-hadron forward-backward asymmetry (Abb) to be Abb = −0.71 ± 0.34 (stat)+0.07−0.08(syst). A fit to the differential cross section, after correcting for the effect of B0B0 mixing, yielded the axial-vector coupling constant of the b-quark (ab):ab = −1.79+0.34−0.32(stat)+0.15−0.14(syst). We also set a 90% confidence level limit of χ

Hypophosphatemic vitamin D-resistant rickets is the most common form of vitamin D-resistant rickets in man. The hypophosphatemic mouse model (Hyp) is phenotypically and biochemically similar to the human disease. Biochemically, hypophosphatemia is the hallmark of this disorder. The cause of the hypophosphatemia is thought to be secondary to a defect in the renal and/or intestinal Na(+)-phosphate transporter. The current studies were designed to investigate and characterize the localization of the defect in the Na(+)-phosphate transporter in this disorder. Phosphate uptake by renal brush border membrane vesicles (BBMV) showed a significant decrease in the slope of the initial rate of phosphate uptake in (Hyp) compared with control mice (0.009 versus 0.013, respectively). The slopes representing initial rates of phosphate uptake by jejunal BBMV were similar in (Hyp) and control mice (0.004 and 0.004, respectively). Kinetics of jejunal Na(+)-dependent phosphate uptake showed a Vmax of 0.63 +/- 0.12 and 0.64 +/- 0.12 nmol/mg protein/15 s in (Hyp) and control mice, respectively, whereas Km values were 0.12 +/- 0.08 and 0.2 +/- 0.11 mM, respectively. Similar kinetic analysis in the kidney showed a Vmax of 0.32 +/- 0.06 and 1.6 +/- 0.1 (p less than 0.01) and Km of 0.07 +/- 0.06 and 0.39 +/- 0.05 (p less than 0.02) in (Hyp) and control mice, respectively. Na(+)-dependent D-glucose uptake by BBMVs of intestine and kidney showed typical overshoot phenomena in (Hyp) and control mice. In order to explore these findings further, Na(+)-phosphate transporter expression from intestine and kidney was accomplished by microinjection of 50 ng of poly(A)+ RNA into Xenopus laevis oocytes. Na(+)-dependent phosphate uptake was expressed 6 days after the microinjection of intestinal and kidney poly(A)+ RNA from control mice. However, expression of the transporter from (Hyp) mice occurred only from the intestine, and not from the kidney. The decrease in the expression of the Na(+)-dependent phosphate transporter was not secondary to accelerated efflux of phosphate or decreased metabolism in oocytes injected with poly(A)+ RNA from (Hyp) mice.(ABSTRACT TRUNCATED AT 400 WORDS)

SUMMARYTo investigate cell surface antigens of activated human cosinophils using monoclonal antibodies, we established a murine anti-human eosinophil monoclonal antibody AE500 by immunizing with blood cosinophils from patients with idiopathic hypereosinophilic syndrome (HES) and characterized the reactivity to a variety of human leucocytes by a fluorescence-activated cell sorter. AE500 reacted with blood cosinophils and neutrophils in nine out of 11 patients with marked eosinophilia (≥ 2500/μI) (seven with idiopathic eosinophilia including HES and two with asthma), but not with those in asthmatic patients with mild eosinophilia (n = 10) or in healthy subjects (n= 8). AE500 did not react with blood lymphoyctcs. monocytes or platelets. AESOO did not react with human myeloid or lymphoid cell lines, including eosinophilic leukemia cell lines EOL-I and EOL-3. The reactivity of AE500 to blood eosinophils and neutrophils in patients with marked eosinophilia changed in relation to blood eosinophil counts and prednisolone therapy. In addition, the reactivity of AE500 to blood eosinophils was increased in three out of four AE500-positive eosinophils by the incubation of the cells with granulocyte-macrophagc colony-stimulating factor (GM-CSF) at 37 C for 30 min. but not with interleukin 3 or interlcukin-5. These results suggest that the anti-eosinophil antibody AE500 detects a cell surface antigen expressed on blood granulocytes in a hypercosinophilic state. This antieosinophil antibody would be useful for analysing the mechanism of eosinophilia.

When the values of dependent variables, such as software size, change greatly relative error should be used to evaluate the fidelity of the prediction model. Relative error is usually defined by the equation: RY 1 =( Z 1 − Y 1 )/ Y 1 where Z , is the estimated value of a dependent variable and Y i is the actual value of the variable for the ith sample data, respectively. According to this definition, RY i has a lower bound of — 1 and an unlimited upper bound. Therefore, lenient evaluation is obtained only in the case of underestimation. To complement this defect, the paper defines the relative error R 1 as: • • If Z i − Y i ⩾ 0 then R i = ( Z i − Y i )/ Y i • • If Z i − Y i R i = ( Z i − Y i )/ Z i R i has no bound for both underestimation and overestimation. Hence a balanced evaluation is possible for both cases. To estimate the parameter values in a software prediction model, the paper proposes using the least squares method, which minimizes the sum of squares of R i , instead of the ordinary least squares method, which minimizes the sum of squares of errors. With the sizing data from 15 completed systems, the paper shows that the method actually makes it possible to obtain better parameter values compared with some other methods, including the ordinary least squares method. The result also shows that there is a distinct possibility that a practical model, which enables sizing estimation in early phases of software development, can be developed for business application systems by the method proposed.

著者人数：70名, 資料番号: SA1002290000

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant, slowly progressive cerebellar ataxia without multisystem involvement. We report a 57-year-old woman with genetically confirmed SCA6 who showed clinical features of olivopontocerebellar atrophy. Conventional T2-weighted and FLAIR MRI demonstrated high signal in the middle cerebellar peduncles, in addition to mild atrophy of the pons and cerebellum.

著者人数：135名, 資料番号: SA1001878000

Pulsed eddy current (PEC) is a promising technique for detection and characterization of hidden corrosion and cracking. Recent development of PEC models offers the prospective of developing model‐assisted approaches to improve measurement procedures and to aid analysis of inspection results for particular NDE problems. To realize these, it is required to extract from measurement data system‐independent waveforms that can be directly compared with model predictions. This paper presents a methodology for charactering a PEC system by determining its transfer function, and for factoring out the system response from measurement data. The method was validated by comparing the extracted waveforms against computed waveforms for layered half space specimens of known conductivity profiles. The present approach was applied to obtain system‐independent benchmark PEC data from fully characterized artificial defect samples, which can be used for model validation of PEC defect signals.

We report on recent progress of a swept high frequency eddy current (SHFEC) technique for nondestructive characterization of residual stresses in engine materials with specific applications to shot‐peened superalloy components. The technique determines conductivity depth profiles by model‐based inversion of SHFEC data, and converts them into residual stress profiles using a material‐based model which generally includes the piezoresistivity (PR) and possibly other non‐PR effects. Improvement in detection coil and upgrades to the measurement system have extended the effective frequency upper bound to 70 MHz. A modified piezoresistivity theory, including the effect of texture on stress‐induced conductivity changes, was developed in light of the experimental evidences of shot‐induced changes of texture in peened Inconel 718 samples. The theory was applied to convert the conductivity profile to a residual stress depth profile, which agrees with the data taken by the standard layer removal XRD method.

Parallel vortices in uniaxial superconductors may attract each other provided they are tilted with respect to the principal crystal directions and the intervortex spacing is on the order of the penetration depth. The vortex-vortex interaction potential and the line energy are evaluated within London theory.

Aromatic material extracted from the Murchison meteorite shows an absorption atλ2200 A similar to the well-known interstellar absorption feature at this wavelength. This suggests a link between interstellar grain clumps containing organics and the presolar component of carbonaceous chondrites.

Background: The turning point in the deterioration of physical function seems to occur between the ages of 70 and 80 years. In particular, muscle strength may decline even more in subjects older than 75. A recent study found that the angiotensin-converting enzyme (ACE) genotype also affects physiological left ventricular hypertrophy. A very limited number of papers have examined genetic differences in resistance and endurance forms of a single sporting discipline. Objective: The purpose of this study was to evaluate the relationship between ACE genotype and physical function by controlling the known confounding factors including dental status. Methods:We selected 431 subjects who were aged 76 years and did not require special care for their daily activities. We conducted a medical examination, followed by 5 physical function tests, as follows: (1) maximum hand grip strength, (2) maximal isometric knee extensor strength, (3) maximal stepping rate for 10 s, (4) one-leg standing time with eyes open and (5) 10-meter maximum walking speed. Subjects were genotyped for the ACE intron 16 Alu insertion. In addition, serum concentrations of total cholesterol, total protein, IgA and IgG were measured at a commercial laboratory. The Eichner index was used as an indicator of occlusal condition. Multiple linear regression analysis was performed to evaluate the relationship between the ACE gene insertion/deletion (I/D) polymorphism and physical function considering confounding factors. Results: The ACE gene I/D polymorphism was positively associated with hand grip strength and 10-meter maximum walking speed. Betas of hand grip strength were 0.09 for I/D (p = 0.022) and 0.12 for insertion/insertion (I/I; p = 0.004). Betas of 10-meter walking speed were –0.11 for I/D (p = 0.093) and –0.14 for I/I (p = 0.039). Dental status such as Eichner index class C was significantly associated with one-leg standing time with eyes open (beta –0.11; p = 0.028). Conclusion: This study suggests that there is a significant relationship between ACE genotype and physical function. In particular, subjects with the ACE deletion/deletion genotype were associated with upper extremities.

This paper reports on a swept high‐frequency eddy current (SHFEC) measurement method developed for electromagnetic nondestructive characterization of residual stresses in shot peened aerospace materials. In this approach, we regard shot‐peened surfaces as modified surface layers of varying conductivity, and determine the conductivity deviation profile by inversion of the SHFEC data. The SHFEC measurement system consists of a pair of closely matched printed‐circuit‐board coils driven by laboratory instrument under software control. This provides improved sensitivity and high frequency performance compared to conventional coils, so that swept frequency EC measurements up to 50 MHz can be made to achieve the smallest skin depth of 80 μm for nickel‐based superalloys. We devised a conductivity profile inversion procedure based on the laterally uniform multi‐layer theory of Cheng, Dodd and Deeds. The main contribution of this paper is the methodology validation. Namely, the forward and inverse models were validated against measurements on artificial layer specimens consisting of metal films with different conductivities placed on a metallic substrate. The inversion determined the film conductivities which were found to agree with those measured using the direct current potential drop (DCPD) method.

This paper describes an eddy current model‐based method for inverting near‐surface conductivity deviation profiles of surface treated materials from swept‐high frequency eddy current (SHFEC) data. This work forms part of our current research directed towards the development of an electromagnetic nondestructive technique for assessing residual stress of shot‐peened superalloy components. The inversion procedure is based on the use of a parameterized function to describe the near‐surface conductivity as a function of depth for a shot‐peened surface, and the laterally uniform multi‐layer theory of Cheng, Dodd and Deeds to calculate the resulting coil impedance deviations. The convergence of the inversion procedure has been tested against synthesized eddy current data. As a demonstration, the conductivity deviation profiles of a series of Inconel 718 specimens, shot peened at various Almen intensities, have been obtained by inversion. Several consistency tests were conducted to examine the reliability of the ...

For advanced uses of eddy current (EC) NDE models in, e.g., model‐assisted POD, there is a need to understand the origin of EC noise sources so that noise estimations can be made for a given set of inspection conditions, in addition to defect signal predictions. This paper focuses on the material‐oriented noise sources that exhibit some universality when isolated from electrical and mechanical noises. Specifically, we report on experimental measurements that show explicit correlations between surface roughness and EC noise as seen in post‐peen EC measurements of shot‐peened roughness specimens. The samples are 3″‐by‐3″ Inconel 718 and Ti‐6A1‐4V blocks, pre‐polished and shot‐peened at Almen intensities ranging from a low of 4N to as high as 16A, created by smaller (∼350 μm) and larger (∼1 mm) diameter zirconium oxide shots. Strong correlations are observed between the Almen intensities and the measured surface roughness. The EC noise correlates equally strongly with the Almen intensities for the superalloy specimens. The correlation for the Ti‐alloy samples is only apparent at higher intensities, while being weak for lower intensities, indicating the grain noise dominance for smoother surfaces.

The pulsed eddy current (PEC) technique has shown considerable promise as a new tool for the detection and characterization of hidden corrosion and cracking. Included among its attributes is the ability to sense deeply buried defects and obtain important information for use in defect characterization, a result that is enabled by the presence of multiple frequency components. This paper presents a laboratory‐based pulsed eddy current system, and an accompanying data analysis methodology that enables quantitative instrumentation characterization. The focus is on the latter aspect, i.e. the system characterization methodology based on the full waveform data and analytical NDE models.. We introduce a linear response function description of the instrumentation effect on measured waveforms, and formulate a procedure to isolate and extract the response function effect out of the waveforms. Finally, we present validation results to demonstrate the validity of the proposed system characterization procedure.

Background Health Assessment Questionnaire (HAQ) is often used to assess functional disabilities, and is closely associated with disease activity and radiographic joint damage in patients with rheumatoid arthritis (RA) 1 . Joint range of motion (ROM) is also affected by inflammation and joint destruction in RA. However, the relationship between HAQ and large joint ROM still remains. Objectives To examine the association of HAQ with clinical parameters including ROM of large joints in patients with RA. Methods We have examined 62 patients with RA that were resistant to disease-modifying anti-rheumatic drugs (DMARDs). The mean age was 58.7 years and mean disease duration was 10.2 years. We measured ROM of cervical spine and large joints (bilateral shoulder, elbow, hip, knee and ankle joints), CRP, MMP-3 DAS28-ESR, SDAI, CDAI, degree of large joint damage (ARASHI status score 2 and HAQ. Correlations of parameters were estimated by Spearman9s rank correlation coefficient. Differences were considered significant if two-sided P-values were Results HAQ was well correlated with DAS28-ESR, SDAI and CDAI as expected. HAQ was not correlated with total ARASHI status score. However, HAQ was significantly correlated with shoulder flexion (r=0.38, P Conclusions We showed that HAQ was associated with ROM of large joint in patients with RA. Specifically, shoulder, elbow and ankle plantar flexion were important determinants of HAQ and, therefore, should be monitored to guide treatment. References Drossaers-Bal KW, et al. Arthritis Rheum. 1999; 42; 1854-1860. Kaneko A, Matsushita I, et al. Mod Rheumatol. 2013; 23; 1053-1062. Disclosure of Interest None declared

Two types of scanning magnetic microscopes (MM) are known nowadays: force magnetic microscopes (FMM) and non-force MM (NFMM) ones. The second type of MM can be used to measure a distribution of the vertical component of magnetic fields over surfaces, including cases such as in a cavity of solid test objects (TO) and inside a liquid TO, without external forces or magnetic influences on the TO. A NFMM with a SQUID detector (SQUID-MM) has the highest magnetic sensitivity among all types of MM. Because of these SQUID-MM features, it is suitable for use in developments of smart materials. For example, it may be used for: counter-terrorism investigations by surveying and decoding of the slight slots left after deletion of the magnetic records on a computer disc by traditional magnetic "scrubber" procedures; surveying and decoding of minute magnetic indications left after a mechanical scrubber procedure of mechanically stamped records of serial numbers on cars and other objects; surveying and measuring magnetic properties of small magnetic particles of the object under investigation for identification of the object; high-sensitivity reading of magnetic records on perspective superconducting carriers. The design of our three-channel SQUID-MM is described in this article. Magnetic 3D scan-pictures of several TO’s are presented also for demonstration.

A local resistance of a low‐temperature polycrystalline silicon in a thin film transistor (TFT) for a liquid crystal display was measured using scanning spreading resistance microscopy for investigating an activation of dopant atoms. The observed TFTs had lightly doped drain (LDD) structures with lengths of 0.6 μm and 1.0 μm. The measured local resistance ranges by 4 – 6 orders of magnitude for measuring points. The resistance data were separated into two groups: the higher resistance data were inside the grains and at the center of the grain boundaries, while the lower resistance data were near‐by the grain boundaries. The lower resistance data were evaluated, since the TFT operation current usually flows through the lower resistance area. From the lower resistance data, the drastic resistance change from the channel to the drain regions, which is LDD, were observed in both samples. The LDD lengths of two samples are found to be approximately 0.6 and 1.0 μm, respectively.

This paper reports on an on‐going project toward developing electromagnetic residual‐stress characterization method. Specifically, we present recent work on an eddy current technique and model‐based inversion method, specific to nickel‐based superalloys. In our approach, we treat residual stress measurements essentially as a “layer‐substrate” problem (a shot‐peened layer on an alloy substrate), to which the swept‐frequency EC technique is applicable. To this end, a high‐sensitivity eddy current system with operating frequency up to 50MHz has been recently developed and validated. We present a description of our instrumentation that includes proprietary probes fabricated by the PCB technology, and laboratory‐grade instruments under software control. The paper also describes the experimental procedure for performance studies, supported by preliminary data that distinguish clearly between surfaces before and after shot‐peening for nickel‐based alloys. In addition, we present forward and inverse model validat...

Wireless multi-hop networks are promising techniques for next generation wireless communications. Multi-hop networks have large channel capacity and can achieve multi-route transmissions. By using multi-route transmissions, we can obtain a route diversity effect at the destination nodes. In order to enhance the diversity effect, we usually adopt forward error correction techniques. Forward error correction techniques and turbo codes effectively work against severe wireless environment including fading channels. The iterative turbo decoder requires accurate channel information to achieve good decoding performance. In multi-hop transmissions, however, the receiver usually measures only the channel information of the last hop and it does not know the channel information of the whole route. In this paper, we propose the turbo coded multi-route multi-hop networks using parity check bits. By using parity bits, we can easily estimate the whole channel information in multi-route multi-hop networks. Using numerical examples, we show that the proposed scheme improves the performance in the fast fading channel conditions.

A new analytical drain current model including variable series resistance for the a-Si:TFT is presented. Results calculated by the model show very good agreement with experimental results for all operating bias conditions and indicate the scalability over different device geometries.

Eddy‐current scans have been carried out on two Inconel‐718 specimens following the application of various levels of shot peening and heat treatments. The conventional analysis of roughened or shot peened surfaces looks at multi‐frequency impedance measurements and interprets the data as a change in conductivity or liftoff. An approach involving the statistical analysis of scanned eddy‐current impedance data is suggested as an alternative that may provide a more sensitive way of determining the treatment history of a component. It is possible that an analysis of these statistical distributions in spatial eddy‐current data could be used to determine the level of remaining residual stress in engine components.

This paper demonstrates the utility of the effective power defined as the logarithmic derivative of eddy current probe impedance with respect to the frequency. When applied to defect characterization in plate geometry, the quantity thus defined correlates well with residual depths of OD cracks, thereby being useful for depth sizing. Using theory and experiment, we show how the segregation of depths can be achieved in terms of the observed power values. It is explained that, unlike the conventional phase‐based method, the effective‐power method can be made robust against lift‐off noise.

A study based on 3‐D boundary element model was carried out to investigate three‐point calibration standard for eddy current (EC) inspection of aerospace structures for surface defects. As the standard covers a wide range of materials, instruments, probes, frequencies and test situations, this model study provides an inexpensive alternative to experimental investigations. Specific conclusions are drawn concerning the response amplitude of reference notches for various test conditions and on the suitability of using vertical amplitude alone for inspections.

This paper presents results from the effort to validate a three‐dimensional boundary element eddy current model. Absolute cylindrical ferrite‐core real‐world probes have been studied for validation in terms of impedance changes due to well‐characterized fatigue cracks and EDM notches. The relationship between prediction and observation, including discrepancies at high frequencies, has been investigated, and a radial basis function neural network based transfer function has been proposed to compensate for the unknown sources of discrepancies. Good agreement has been observed between model predicted data and experimental data.

The paper describes a new inverse method to determine eddy current probe internal parameters, such as coil diameters, coil height, and ferrite‐core dimensions if present, from impedance data. The approach uses an inverse model based on a radial basis function neural network, trained by a boundary element model. Performance of the approach is evaluated not only against computed data but also against experimental data collected with an impedance analyzer and a commercial eddy current tester. The estimated parameters are compared with X‐ray radiography data.

A recent effort toward developing electromagnetic, nondestructive method for characterizing residual stress on the surface of rotating engine components is described. It is explained that resistivity measurement such as eddy current or injection current methods can be indeed candidates, if one can successfully discriminate two competing sources of resistivity change after shot peening, i.e. stress and dislocation. A profile‐assumed inversion method is proposed to utilize characteristic profile shape differences between the two sources, so that the required discrimination can be achieved.

Simulation results of the eddy current modeling code ECSIM on an Inconel tube mock‐up were compared to existing experimental results on inner and outer circumferential notches inspected at two different frequencies, observing the influence of a geometrical effect such as tube thickness. The EC probe used for this setup represented a number of difficulties, such as a ferrite core for the excitation coil and a differential pickup coil arrangement with a small inner diameter. The results were instructive, showing that special care must be taken to generate highly symmetrical meshes, as minor differences are amplified by the differential setup. We present qualitative and quantitative results and focus on the lessons learned from this code validation exercise.

We have developed the phased tracking method for measuring the minute change in thickness during one heartbeat and the elasticity of the arterial wall with transcutaneous ultrasound. When this method is applied to a plane perpendicular to the axis of the artery (short-axis plane) using a linear-type probe, only an ultrasonic cam which passes through the center of the artery coincides with the direction of the change in thickness. At other beam positions, the wall motion cannot be accurately tracked because the direction of wall expansion slips of the beam. To obtain the cross-sectional image of elasticity in the short-axis plane using transcutaneous ultrasound, in this paper, the directions of ultrasonic beams are designed so that each beam always passes through the center of the artery thus they always coincide with the direction of the wall expansion. In basic experiments, the accuracy in elasticity measurement was evaluated using a silicone rubber tube. In in vitro experiments using an extracted human femoral artery, the measured elasticity image was compared with the pathological image. In in vivo experiments, the minute change in wall thickness was measured along each ultrasonic beam. and the cross-sectional image of elasticity was obtained in the short-axis plane with transcutaneous ultrasound.

This database design is associated with a research program aiming at characterizing eddy‐current noise sources by scanning approximately thirty Inconel and titanium‐alloy flat‐plate specimens. By nature, such a project generates a large amount of data, as any one specimen may be scanned with multiple probes and subjected to multiple treatments throughout its life in the project. Statistical analyses will be performed after each scan, and these analyses will be correlated with a variety of parameters. Our database is constructed to manage this complex set of eddy‐current data, using a commercial, fully relational database program.

We present a rectifying manganite-titanate heterojunction exhibiting a magnetic field tunable depletion layer. This creates a large positive magnetocapacitance, a direct measure of the field-induced reduction of the effective depletion width across the junction. Furthermore, the reduction of the junction barrier shifts the forward bias characteristics, giving exponentially-enhanced differential magnetoresistance, occurring despite the absence of a spin filter. These results provide a unique probe of a Mott insulator/band insulator interface, and further suggest new electronic devices incorporating the magnetic field sensitivity of these strongly correlated electron materials., Comment: 14 pages with 4 figures

Applicability of the plate wave technique was investigated in this study to detect small defects in the web gap region of the steel plate girder. Torsion induced fatigue cracking is one of the most serious problems for steel bridges. As the conventional inspection method, visual inspection has been applied. However, this method is not always accurate. In addition, accessibility of the inspectors is also a serious problem. This study aims at the application of the plate wave ultrasonic testing to detect a fatigue crack in the web gap area and monitor its propagation. As the first step, the influence of a stiffener and detectability of one or more holes in the web gap were investigated.

We have studied a power-by-wire/fly-by-light (PBW/FBL) system for years and developed prototype equipment such as an optical data bus, electric smart actuator and flight control computer. The optical data bus includes commercial based single mode fiber, optical couplers and E/O (electro/optical) transceiver that is small enough to be installed inside each piece of electronic equipment. The electric smart actuator is a triple redundant 270 V DC EMA (electro mechanical actuator) package with embedded control electronics. Also, a new fault detection and reconfiguration capability was demonstrated using the flight control computer prototype. The functional test and environmental test for each component are almost completed. Currently, we are starting the system integration bench test in which all prototype equipment will be connected using the optical data bus. We present the prototype design, equipment test results and system integration test plan.