Research on Non-Contact Weak Current Detection Technology

With the continuous development of industrial technology, the weak current plays an increasingly important role in all fields of life. In order to facilitate the user to carry, the study of contactless weak current measurement technology is also emerging. This article’s design idea is based on two-dimensional reluctance sensor device built non-contact weak current detection system. The system uses the reluctance sensor HMC1002 to collect the current signal and the temperature sensor DS18B20 to compensate the temperature. The signals collected by the reluctance sensor and the temperature sensor are extremely weak. After being amplified by the amplifying circuit, the signal is conducive to subsequent detection and processing. Filter circuit can filter out interference signals to achieve the goal of improving accuracy. After the corresponding algorithm of the microcontroller will convert the signal voltage, easy to read and store, thus designing a non-contact current measurement capable of detecting weak currents and achieving higher accuracy.

Non-Contact System for Global Reporting Format (GRF) Automation: Contaminant Body Detection and Depth Estimation in the Case of Rainy Weather

The paper designed a non-contact system in order to perform the application (on a runway) of the Global Reporting Format (GRF) developed by International Civil Aviation Organization (ICAO). The system involves devices that film the surface (a runway in our case) from the air and displays the contaminant (water) body and measures the depth of the water automatically during the inspection. While measuring, data are sent to a computer used as a receiver. The developed devices are automatic devices implemented specially to use during rainy weather or even for some other cases. The aerial system uses a raspberry pi 4 model B, a camera, a laser sensor, an ultrasonic module, a Virtual Network Computing (VNC) and python codes developed by the authors. Results obtained show that using these devices to retrieve the Runway Condition Report (RCR) is very fast and human presence on the runway is not needed. The results obtained using these devices show that the method used herein is a proper solution to the GRF issues in the rainy areas, where the contaminant body detection and the accurate depth measurement were not well estimated because of the lack of a suitable method.

Identification of plasma microRNA-21 as a biomarker for early detection and chemosensitivity of non-small cell lung cancer

Studies have shown cell-free microRNA(miRNA) circulating in the serum and plasma with specific expression in cancer,indicating the potential of using miRNAs as biomarkers for cancer diagnosis and therapy.This study was to investigate whether plasma miRNA-21(miR-21) can be used as a biomarker for the early detection of non-small cell lung cancer(NSCLC) and to explore its association with clinicopathologic features and sensitivity to platinum-based chemotherapy.We used real-time RT-PCR to investigate the expression of miR-21 in the plasma of 63 NSCLC patients and 30 healthy controls and correlated the findings with early diagnosis,pathologic parameters,and treatment.Thirty-five patients(stages IIIB and IV) were evaluable for chemotherapeutic responses:11 had partial response(PR);24 had stable and progressive disease(SD+PD).Plasma miR-21 was significantly higher in NSCLC patients than in age-and sex-matched controls(P<0.001).miR-21 was related to TNM stage(P<0.001),but not related to age,sex,smoking status,histological classification,lymph node status,and metastasis(all P>0.05).This marker yielded a receiver operating characteristic(ROC) curve area of 0.775(95% CI:0.681-0.868) with 76.2% sensitivity and 70.0% specificity.Importantly,miR-21 plasma levels in PR samples were several folds lower than that in SD plus PD samples(P=0.049),and were close to that in healthy controls(P=0.130).Plasma miR-21 can serve as a circulating tumor biomarker for the early diagnosis of NSCLC and is related to the sensitivity to platinum-base chemotherapy.

A Novel Uniplanar Multi-Electrode Capacitive Sensor for In-Situ Weathering Damage Detection of Nonmetallic Materials

A uniplanar capacitive sensor with 5-electrodes on one plane substrate and a large reflector electrode,was designed to get the corresponding capacitance information for weathering damage detection of non-metallic materials exposed to a service environment.A 2-D finite-element method was employed to simulate the electric potential distribution and capacitance measurements for the sensor.2 marble slabs,one was healthy and the other was notched,were experimentally detected.Both the simulation and the preliminary experimental results show that the measured capacitances decrease after weathering damage occurs in nonmetallic material.The reflector can enlarge the sensitive depth.The weathering assessment of nonmetallic materials can be done by processing the measured capacitances.The proposed approach can effectively detect the weathering damage of nonmetallic material and can be practically used for in-situ weathering damage evaluation.

Optical generation,detection and non-destructive testing applications of terahertz waves

Optoelectronic terahertz generation and detection play a key role in the applications of non-destructive testing,which involves different areas such as physics,biological,material science,imaging,explosions detection,astronomy applications,semiconductor technology and superconductiong electronics. In this article,we present a reviewof the principle and performance of typical terahertz sources,detectors and non-destructive testing applications. On this basis,the newdevelopment and trends of terahertz radiation detectors are also discussed.

A Simple and Rapid Method for the Detection of Non-Ionic Surfactants

A spectrophotometric approach for the detection of non-ionic surfactant (Triton X-100) has been proposed in this paper. This method does not involve extraction of the ion-associate with harmful solvents, but employs adhesion of the ion-association of potassium/non-ionic surfactants complex and tetraphenylporphyrin tetrasulfonic acid obtained by vigorous shaking. The adhered ion-associate was dissolved with water and its absorbance was measured. The sensitivity for Triton X-100 was determined to be 0.146 (expressed as absorbance of 1 mg/L solution). The adhesion tendency of ion-associate was found to be dependent on the water contact angle, which in turn was influenced by a high adhesion of the ion-associate and by low blank values. In this respect, a tetrafluo-roethylene vessel was found to be the most suitable for the detection of non-ionic surfactants. This spectrophotometrical method is simply and rapidly performed by a procedure based on mechanical shaking and can be employed to detect non-ionic surfactants containing more than 7 polyethylene oxide units.

Non-coherent sequence detection scheme for satellite-based automatic identification system

The satellite-based automatic identification system (AIS) receiver has to encounter the frequency offset caused by the Doppler effect and the oscillator instability. This paper proposes a non-coherent sequence detection scheme for the satellite-based AIS signal transmitted over the white Gaussian noise channel. Based on the maximum likelihood estimation and a Viterbi decoder, the proposed scheme is capable of tolerating a frequency offset up to 5% of the symbol rate. The complexity of the proposed scheme is reduced by the state-complexity reduction, which is based on per-survivor processing. Simulation results prove that the proposed non-coherent sequence detection scheme has high robustness to frequency offset compared to the relative scheme when messages collision exists.

A New UKF Based Fault Detection Method in Non-linear Systems

To detect the bias fault in stochastic non-linear dynamic systems, a new Unscented Kalman Filtering（UKF） based real-time recursion detection method is brought forward with the consideration of the flaws of traditional Extended Kalman Filtering（ EKF）. It uses the UKF as the residual generation method and the Weighted-Sum Squared Residual （WSSR） as the fault detection strategy. The simulation results are provided which demonstrate better effectiveness and a higher detection ratio of the developed methods.

Non-Detection Probability of a Diffusing Target by a Stationary Searcher in a Large Region

We revisit one of the classical search problems in which a diffusing target encounters a stationary searcher. Under the condition that the searcher’s detection region is much smaller than the search region in which the target roams diffusively, we carry out an asymptotic analysis to derive the decay rate of the non-detection probability. We consider two different geometries of the search region: a disk and a square, respectively. We construct a unified asymptotic expression valid for both of these two cases. The unified asymptotic expression shows that the decay rate of the non-detection probability, to the leading order, is proportional to the diffusion constant, is inversely proportional to the search region, and is inversely proportional to the logarithm of the ratio of the search region to the searcher’s detection region. Furthermore, the second term in the unified asymptotic expansion indicates that the decay rate of the non-detection probability for a square region is slightly smaller than that for a disk region of the same area. We also demonstrate that the asymptotic results are in good agreement with numerical solutions.

Compressed sensing and Otsu's method based binary CT image reconstruction technique in non-destructive detection

This paper tries to address the problem of binary CT image reconstruction in non-destructive detection with an algorithm based on compressed sensing(CS) and Otsu's method, which could reconstruct binary CT image of test object from incomplete detection data. According to binary CT image characteristics, we employ Splitbregman method based on L1/2regularization to solve piecewise constant region reconstruction. To improve the reconstructed image quality from incomplete detection data, we utilize a priori knowledge and Otsu's method as the optimization constraint. In our study, we make numerical simulation to investigate our proposed method,and compare reconstructed results from different reconstruction methods. Finally, the experimental results demonstrate that the proposed method could effectively reduce noise and suppress artifacts, and reconstruct high-quality binary image from incomplete detection data.

Determination of Roxithromycin Tablets by Capillary Electrophoresis Employing Non-aqueous Media with Square-wave Amperometric Detection

A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination were studied. The data was modified by spline wavelet least square (SWLS). The method is simple, rapid and highly reliable for routine analysis.

Laser-Assisted Generation and Detection of Non-Nuclear Low-Energy Neutrino-Antineutrino Beams

It is argued that conservation of energy, momentum, and spin, and QM transition probabilities, allow the generation and detection of low-energy (eV) neutrinos and antineutrinos in intra-atomic (non-nuclear) laser transitions. Two-quantum transitions between an upper and lower excited state in a lasing medium can support paired emissions of a neutrino and a recoiling counter-propagating anti-neutrino, each carrying half of the lasing transition energy. Their propagations are in opposite directions along the same axis as that of the intracavity laser beam in the lasing medium. Estimates show that the probability of this two-quantum event is on the order of 10&minus;7 compared to a one-quantum stimulated emission of a laser photon. Absorptions or emissions of single antineutrinos or neutrinos by molecular/atomic matter are impossible because they carry spins s = &plusmn;h/2 which violates &Delta;s = &plusmn;nh (n = integer) required for such processes. However, inside a laser, emissions of photons from excited states can be stimulated by neutrinos or anti-neutrinos passing through, provided their undulation frequency is resonant with the transition frequency. This is because in stimulated emissions, neutrinos or antineutrinos are not absorbed, and spin conservation violation is not an issue. Thus, detection of the passage of a laser-generated antineutrino or neutrino beam through a second “receiver” laser is possible provided that the transition energy in the second laser equals half the transition energy of the laser that emits the antineutrino-neutrino beam to be detected.

Detection and Characterization of β-Lactamase Encoding Genes in Carbapenem Non-Susceptible Gram-Negative Bacteria and Susceptibility of Isolates to Ceftazidime-Avibactam at a New York City Community Hospital

A surveillance study was undertaken to identify prominent β-lactamase encoding genes in 131 carbapenem non-susceptible gram-negative clinical isolates at a New York City community hospital. KPC carbapenemases were detected in 89% of Enterobacteriaceae as well as additional TEM, SHV, and CTX-M class A enzymes. OXA-23 and OXA-24 were the prevalent class D carbapenemases identified in Acinetobacter species. One OXA-23 in M. morganii and one OXA-48 in K. pneumoniae were also identified. Among class C β-lactamases CMY, ACT/MIR, DHA, and FOX were detected. The in vitro activity of ceftazidime-avibactam by E-test methodology was tested with minimal inhibitory concentrations (MIC) of ≤3 μg/ml for 97.8% of all Enterobacteriaceae, MIC50/90 of 16/>256 μg/ml for carbapenem non-susceptible Acinetobacter, and 3/6 μg/ml for carbapenem non-susceptible Pseudomonas aeruginosa. Periodic surveillance of isolates to characterize current and emerging β-lactamase genotypes present in local isolates may help identify outbreak situations, provide assistance to infection control and antibiotic stewardship programs, and potentially improve patient outcomes.

Multi-Energy Gamma-Ray Attenuations for Non-Destructive Detection of Hazardous Materials

We present a non-destructive method (NDM) to identify minute quantities of high atomic number (Z) elements in containers such as passenger baggage, goods carrying transport trucks, and environmental samples. This method relies on the fact that photon attenuation varies with its energy and properties of the absorbing medium. Low-energy gamma-ray intensity loss is sensitive to the atomic number of the absorbing medium, while that of higher-energies vary with the density of the medium. To verify the usefulness of this feature for NDM, we carried out simultaneous measurements of intensities of multiple gamma rays of energies 81 to 1408 keV emitted by sources 133Ba (half-life = 10.55 y) and 152Eu (half-life = 13.52 y). By this arrangement, we could detect minute quantities of lead and copper in a bulk medium from energy dependent gamma-ray attenuations. It seems that this method will offer a reliable, low-cost, low-maintenance alternative to X-ray or accelerator-based techniques for the NDM of high-Z materials such as mercury, lead, uranium, and transuranic elements etc.

Mathematic model and tooth contact analysis of a new spiral non-circular bevel gear

A novel spiral non-circular bevel gear that could be applied to variable-speed driving in intersecting axes was proposed by combining the design principles of non-circular bevel gears and the manufacturing principles of face-milling spiral bevel gears.Unlike straight non-circular bevel gears,spiral non-circular bevel gears have numerous advantages,such as a high contact ratio,high intensity,good dynamic performance,and an adjustable contact region.In addition,while manufacturing straight non-circular bevel gears is difficult,spiral non-circular bevel gears can be efficiently and precisely fabricated with a 6-axis bevel gear cutting machine.First,the generating principles of spiral non-circular bevel gears were introduced.Next,a mathematical model,including a generating tooth profile,tooth spiral,pressure angle,and generated tooth profile for this gear type was established.Then the precision of the model was verified by a tooth contact analysis using FEA,and the contact patterns and stress distributions of the spiral non-circular bevel gears were investigated.

Static Radical Stiffness and Contact Behavior of Nonpneumatic Mechanical Elastic Wheel

Conventional pneumatic tires exhibit disadvantages such as puncture,blowout at high speed,pressure maintenance,etc.Owing to these structural inevitable weaknesses,non?pneumatic tires have been developed and are investigated.A non?pneumatic mechanical elastic wheel(NPMEW)is introduced and investigated as a function of static radical stiffness characteristics and contact behavior.A bench test method is utilized to improve the riding comfort and the traction traffic ability of NPMEW based on tire characteristics test rig,and the static radical stiffness characteristics and the contact behavior of NPMEW are compared with that of an insert supporting run?flat tire(ISRFT).The vertical force?deformation curves and deformed shapes and contact areas of the NPMEW and ISRFT are obtained using a set of vertical loads.The contact behavior is evaluated using extracted geometrical and mechanical feature parameters of the two tires.The results indicate that the NPMEW appears to exhibit considerably high radical stiffness,and the numerical value is dependent on the mechanical characteristic of the flexible tire body and hinge units.NPMEW demonstrates more uniform contact pressure than ISRFT within a certain loading range,and it can efficiently mitigate the problem of stress concentration in ISRFT shoulder under heavy load and enhance the wear resistance and ground grip performances.

CFAR DETECTORS FOR HIGH RESOLUTION RADAR IN NON-GAUSSIAN CLUTTER

For high resolution radar, the echoes of target come from several points rather than one point as in low resolution radar. In this case the target is called an extended target. This paper presents two CFAR detectors for such a target in non Gaussian clutter, which are CA CFAR and OS CFAR detectors. The detection performances of the two detectors are evaluated.

Statistical moment-based structural damage detection method in time domain

A novel structural damage detection method with a new damage index,i.e.,the statistical moment-based damage detection（SMBDD） method in the frequency domain,has been recently proposed.The aim of this study is to extend the SMBDD method in the frequency domain to the time domain for building structures subjected to non-Gaussian and non-stationary excitations.The applicability and effectiveness of the SMBDD method in the time domainis verified both numerically and experimentally.Shear buildings with various damage scenarios are first numerically investigated in the time domain taking into account the effect of measurement noise.The applicability of the proposed method in the time domain to building structures subjected to non-Gaussian and non-stationary excitations is then experimentally investigated through a series of shaking table tests,in which two three-story shear building models with four damage scenarios aretested.The identified damage locations and severities are then compared with the preset values.The comparative results are found to be satisfactory,and the SMBDD method is shown to be feasible and effective for building structures subjected to non-Gaussian and non-stationary excitations.

NON-CONTACT MEASUREMENT SYSTEM OF FREEFORM SURFACE AND NURBS RECONSTRUCTION OF MEASUREMENT POINTS

Based on the development of the non-contact measurement system of free-formsurface, NURBS reconstruction of measurement points of freeform surface is effectively realized bymodifying the objective function and recursive procedure and calculating the optimum number ofcontrol points. The reconstruction precision is evaluated through Ja-cobi's transformation method.The feasibility of the measurement system and effectiveness of the reconstruction algorithm aboveare proved by experiment.

Diagnostic aids for detection of oral precancerous conditions

Oral cancer has a tendency to be detected at late stage which is detrimental to the patients because of its high mortality and morbidity rates. Early detection of oral cancer is therefore important to reduce the burden of this devastating disease. In this review article, the most common oral precancerous lesions are discussed and the importance of early diagnosis is emphasized. In addition, the most common non-invasive oral cancer devices that can aid the general practitioners in early diagnosis are also discussed.