Narrow Measurement Range Research Articles

Self-powered and speed-adjustable sensor for abyssal ocean current measurements based on triboelectric nanogenerators

The monitoring of currents in the abyssal ocean is an essential foundation of deep-sea research. The state-of-the-art current meter has limitations such as the requirement of a power supply for signal transduction, low pressure resistance, and a narrow measurement range. Here, we report a fully integrated, self-powered, highly sensitive deep-sea current measurement system in which the ultra-sensitive triboelectric nanogenerator harvests ocean current energy for the self-powered sensing of tiny current motions down to 0.02 m/s. Through an unconventional magnetic coupling structure, the system withstands immense hydrostatic pressure exceeding 45 MPa. A variable-spacing structure broadens the measuring range to 0.02–6.69 m/s, which is 67% wider than that of commercial alternatives. The system successfully operates at a depth of 4531 m in the South China Sea, demonstrating the record-deep operations of triboelectric nanogenerator-based sensors in deep-sea environments. Our results show promise for sustainable ocean current monitoring with higher spatiotemporal resolution.

B-321 Development of Chemiluminescent Enzyme Immunoassay (CLEIA) for Detecting Methotrexate in Blood

Abstract Background Methotrexate (MTX) is a folate metabolism antagonist used in the treatment of rheumatoid arthritis, psoriasis, and antineoplastic agents. Therapeutic drug monitoring (TDM) is required to avoid serious adverse reactions of high-dose MTX/leucovorin rescue therapy or in patients with possible delayed excretion due to renal dysfunction or other factors. Although there are many reagents for MTX measurement based on the immunoassay method, they have a narrow measurement range to 2 µmol/L. Therefore, high concentration samples often make users conduct dilution and retest. In addition, most reagents have a cross-reactivity rate of over 40% with 2,4-diamino-N10-methylpteroic acid (DAMPA), one of the metabolites of MTX, so users must take note in the interpretation of measurement results. We have established an antibody with high specificity against MTX, and have developed a fully-automated, chemiluminescence immunoassay for LUMIPULSE® L2400 system for detecting MTX in blood, Lumipulse Presto® Methotrexate, which can significantly improve the issues described above. Methods MTX assay is a one-step competitive immunoassay on the LUMIPULSE® L2400 System (FUJIREBIO INC.), which requires 10 µL of sample. The resulting reaction signals are derived within 30 min/sample, and are proportional to the amount of MTX in the sample allowing quantitative determination of MTX in plasma or serum. Results The detection limit of the assay was 0.019 µmol/L, and the limit of quantitation was 0.030 µmol/L. A 20-day precision study was performed during a 31-day period using two controls and three panel specimens, and within-laboratory precision showed CV ≤ 3.1 %. Linearity was demonstrated over the range 0.017–28.821 µmol/L. No interference was observed with unconjugated (≤20.1 mg/dL) or conjugated bilirubin (≤20.2 mg/dL), chyle (≤1770 FTU), hemoglobin (≤450 mg/dL), and RF (rheumatoid factor, ≤5522 IU/mL). The correlation coefficient and the regression slope of this assay and LC-MS/MS were 1.00 and 1.0, respectively (N = 171). Compared to existing immunoassay reagents, the assay showed much lower cross-reactivity to DAMPA. Conclusion The performance of our novel MTX assay using LUMIPULSE® L2400 system was satisfactory, suggesting it is useful for routine analysis. In particular, the measurement range is wide, 0.030 to 25.000 µmol/L, which greatly reduces the frequency of dilution and retest of high concentration samples. Used with the auto dilution system in LUMIPULSE® L2400, it is possible to measure almost all clinical specimen automatically. Because of the low cross-reactivity with DAMPA, it is expected to be utilized in patient receiving glucarpidase. Acknowledgment: Some of the samples were provided in accordance with “Guidelines for clinical measurement and diagnosis technology improvement project”. The guidelines are promoted by Tsukuba Medical Laboratory of Education and Research Center, and University of Tsukuba Hospital, Japan.

Multi-Frequency Fringe Projection Profilometry: Phase Error Suppression Based on Cycle Count Adjustment

Fringe projection profilometry is one of the most widely used three-dimensional measurement techniques at present, in which phase is the key factor for the accuracy of dimensional measurements. Jumping errors may occur due to improper handling of truncation points in phase unwrapping. Meanwhile, projective dual-frequency grating has the shortcomings of a narrow measurement range and coarse projection fringe due to the requirements of an overlapping grid. To address the above problems, this paper puts forward an improved multi-frequency heterodyne phase unwrapping approach. Firstly, the phase principal values of three frequencies are obtained by the standard four-step phase-shifting approach, and two wrapped phases with lower frequencies are obtained through the dual-frequency heterodyne phase unwrapping approach. Then, the decimal part of the fringe order is again calculated using the dual-frequency heterodyne principle, and the actual value of the current decimal part is calculated from the phase principal values of the grating fringe corresponding to the fringe order. Then, a threshold is set according to the error of the phase principal value itself, and the differences between this threshold and the above calculated and theoretical values are compared. Finally, the absolute phase is corrected by adjusting the number of cycles according to the judgment results. Experiments show that the improved approach can achieve a correction rate of more than 96.8% for the jumping errors that occur in phase unwrapping, and it is also highly resistant to noise in the face of different noises. Furthermore, the approach can measure the three-dimensional morphology of objects with different surface morphologies, indicating the certain universality of the approach.

Terahertz Biaxial Strain Sensor Based on Double-Upright Cross Metamaterial

In this article, a terahertz metamaterial biaxial strain pressure sensor structure is proposed, which can address the problems of the low sensitivity, the narrow pressure measurement range, and the uniaxial-only detection of existing terahertz pressure sensors. The performance of the pressure sensor was studied and analyzed using the time-domain finite-element-difference method. By changing the substrate material and optimizing the structure of the top cell, the size of the structure that can simultaneously improve the range and sensitivity of the pressure measurements was determined. The simulation results show that the sensor has a pressure-sensing effect in the frequency range of 1.0–2.2 THz under the conditions of transverse electric (TE) and transverse magnetic (TM) polarization, and the sensitivity can reach up to 346 GHz/μm. The proposed metamaterial pressure sensor has significant applications in the remote monitoring of target structure deformation.

A Novel 550-fs Time-Resolution 7.5-bit Stochastic Time-to-Digital Converter Based on Two Arbiter Groups

This paper presents a novel two arbiter groups based stochastic time-to-digital converter (STDC) to achieve a better linearity and larger measurement range compared to a traditional STDC. Traditional STDCs with one arbiter group have a bad linearity and narrow measurement range, for the nonlinear time-to-digital transfer function that described by a Gaussian cumulative distribution function (CDF). To improve the linearity, a basic two arbiter groups based STDC is proposed firstly. Through properly shifting the time offset distributions of the two arbiter groups away from each other by applying a global time offset reference to them, a virtual uniform distribution could be formed between the two shifted time offset mean values. To achieve a large measurement range, a dual-input dual-output periodic signal generator (DIDO-PSG) and a global time offset setting circuit (GTOSC) are further designed for the proposed STDC to obtain two pairs of time offset distributions with twice measurements for one input time interval. Through properly setting the mean values of the four time-offset distributions based on GTOSC, an overall transfer function with a large linear part that contributes to a good linearity could be achieved. Finally, a test chip prototype fabricated in a 0.18-μm CMOS technology demonstrates 550-fs time resolution and 0.105-ns measurement range with –1.81 LSB INL at 50MS/s, which is much better than traditional STDCs.

Contactless AC/DC Wide-Bandwidth Current Sensor Based on Composite Measurement Principle.

With the accelerated construction of the smart grid, new energy sources such as photovoltaic and wind power are connected to the grid. In addition to power frequency, the current signal of power grid also includes several DC signals, as well as medium-high and high-frequency transient signals. Traditional current sensors for power grids are bulky, have a narrow measurement range, and cannot measure both AC and DC at the same time. Therefore, this paper designs a non-intrusive, AC-DC wide-bandwidth current sensor based on the composite measurement principle. The proposed composite current detection scheme combines two different isolation detection technologies, namely tunneling reluctance and the Rogowski coil. These two current sensing techniques are complementary (tunneling magnetoresistive sensors have good low-frequency characteristics and Rogowski coils have good high-frequency characteristics, allowing for a wide detection bandwidth). Through theoretical and simulation analysis, the feasibility of the composite measurement scheme was verified. The prototype of composite current sensor was developed. The DC and AC transmission characteristics of the sensor prototype were measured, and the sensitivity and linearity were 11.96 mV/A, 1.14%, respectively. Finally, the sweep current method and pulse current method experiments prove that the designed composite current sensor can realize the current measurement from DC to 17 MHz.

Frequency sweep extension using the Kerr effect for static temperature measurement range enhancement in Chirped Pulse φ-OTDR.

In Chirped Pulse φ-OTDR systems used for sensing temperature or strain along an optical fiber, the largest disturbance between two single-shot measurements that can reliably be detected depends on the range of frequencies swept by the chirped pulse. If electrical modulation is used to generate the laser frequency sweep, the achievable sweeping range is limited by the electrical components, leading to a narrow measurement range for static measurements. In this work, we demonstrate the extension of the frequency range of a chirped laser pulse by all-optical means using evenly spaced frequency sidebands generated via the Kerr effect to improve the Chirped Pulse φ-OTDR measurement range. We report chirp extensions by factors up to 13 and apply the effect to achieve a sixfold increase in the measurement range of a Chirped Pulse φ-OTDR system measuring the temperature of a random fiber grating array. The method described in this paper can be applied to other optical systems utilizing chirped laser pulses and allow for variable extension of their chirping range.

Fast structured illumination microscopy with a large dynamic measurement range.

Fast structured illumination microscopy plays an important role in micro-nano detection due to the features of high accuracy, high efficiency, and excellent adaptability. The existing method utilizes the linear region of the axial modulation response curve (AMR), and by building the relationship between the modulation and the real height, achieves topography recovery. However, the traditional method is limited to narrow dynamic measurement range due to the linear region of the AMR being very short. In this paper, a double-differential fast structured illumination microscopy (DDFSIM) is proposed. By introducing two additional detectable branches for building the double-differential axial modulation response curve (DDAMR), the proposed method can obtain a large dynamic measurement range. In the measurement, three charge-coupled devices are respectively placed in and behind and before the focal plane to generate three axial modulation response curves. Three AMRs are used to set up the DDAMR, which has a large dynamic measurement range. Through simulation and experimental verification, the measurement range of DDFSIM is twice that of the conventional method under the same system parameters.

Highly sensitive differential fiber-optic SPR sensor in telecom band.

We proposed a differential fiber-optic SPR remote sensor with ultra-high sensitivity in telecom band. The working band of the sensor is designed as the C-band which is the low loss band of optical fiber communication aiming to improve the sensitivity and enable the capability of remote monitoring. The sensor head is a BK7 prism coated with Au/TiO2 films, enabling two channels for differential intensity interrogation. The intensities of the reflected lights through the channels vary oppositely within the measurement range of refractive index. Due to the sharp dip of angular resonant response in the C-band, the differential signal produces a steep slope as the refractive index of the sample varies, thus higher sensitivity is expected in a narrow measurement range. According to the results, the sensitivity is as high as 456 V/RIUs within the narrow measurement range of 1.3×10-2 RIUs and the resolution reaches to 6×10-6 RIUs. The measurement range can be tuned conveniently by adjusting the thickness of TiO2 film and can be expanded by increasing the number of sensing channels, which provides great convenience for the application of biosensor requiring high sensitivity.

Design and experimental study of the biorthogonal linkage laser self-mixing angle sensor

In order to make up the defects of low-resolution and narrow measurement range ubiquitous in the current angle-measurement method, a biorthogonal linkage laser self-mixing angle sensor is designed for the micro-radian angular measurement over the full-circle range by taking the Acrylonitrile–butadiene–styrene resin as the material and adopting the 3D printing technology. The experimental results are in excellent agreement with the theoretical values, of which implies that the tool is capable of measuring the angle with effectively and accurately. Furthermore, the deviation degree between the measured and actual angle, and the experimental error are further investigated and discussed. As a result, this self-mixing angle sensor can greatly improve the angle measurement accuracy and reduce the experimental error rate. In the case of different rotating angles of 250 and 500 μrad, which corresponding to the angular resolution is better than 29.53 μrad and the relative error can be smaller than 3.18×10−4 %.

Meso-Reconstruction of Wool Keratin 3D "Molecular Springs" for Tunable Ultra-Sensitive and Highly Recovery Strain Sensors.

Wool keratin (WK) consists of a large number of α-helices, which are just like many molecular-scale springs. Herein, the construction of 3D WK molecular spring networks are reported by cross-linking individual WK molecules via a Michael addition reaction. The as-prepared springs display a superior recovery capability with unusual nonlinear elasticity, very low dissipative energy, and turntable elastic constant achieved by adjusting the chemical crosslinking density of WK networks. Owing to these unique characteristics, the 3D WK networks based flexible strain sensors reveal a high sensitivity, broad sensing ranges, and extremely long and stable performance. While normal highly sensible strain sensors, obtained by highly sophisticated surface or bulk patterning, often exhibit a relatively narrow range of measurements and limited life cycles. Such the WK mediated sensing materials have widespread applications in wearable electronics, such as detection and tracking of different human motions, and even discern voice during speaking.

High-sensitivity resistive humidity sensor based on graphitic carbon nitride nanosheets and its application

Currently, most humidity sensors have problems such as narrow measurement range, long response time and poor reversibility. In this work, we developed a resistive humidity sensor based on graphitic carbon nitride (g-C3N4) nanosheet film on epoxy substrate with Cu/Ni electrodes. The structure, morphology and composition properties of the g-C3N4 were analyzed by XRD, SEM, TEM, FTIR and XPS. The humidity sensing results show that the g-C3N4 film sensor has the advantages of high sensitivity (6457548.8 Ω/%RH), good reversibility and fast response/recovery time (0.3/8.5 s). The humidity sensing performance of g-C3N4 overpasses the other sensors based on graphene oxide (GO), ZnO, anodic aluminum oxide (AAO), SnO2, Bi6S2O15 and common composites. The g-C3N4 film sensor exhibits great application prospect in humidity alarm device, automatic diaper alarm and non-contact testing of cultural relics, which have advantages such as strong anti-interference capability, low cost and easy to use.

Simulation of the Effect of Cutting Angle in Lathe Process onDistribution of Cutting Temperature

Lathe machining process (turning) is one of the metal cutting operation is the most widely used. At the time of the cutting process almost all cutting energy is converted into heat through friction between furious with the chisel and the chisel with the workpiece, as well as the destruction molekulen or atomic bonding in the field of shear (shear plane). The heat produced will be distributed in workpiece surface, chisel eye, and furious. High cutting temperatures as a result of friction between the eyes chisel and workpiece, will have an impact on the wear rate of the active surface of the plastic deformation chisel and chisel. Cutting temperature can be measured in various ways, either directly or indirectly. However, in its application, direct measurement will find it difficult to reach the area of the cutting temperature. The difficulty is due to the relatively narrow measurement range, disturbance of movements machinery and hindered by furious that formed during the machining process is done. To overcome this we can do indirectly measuring process for measuring the temperature of the cutting. Indirect measurement can be done by simulation or modelling. This research uses Tungsten carbide as a cutting tool and AISI 4340 as the workpiece in the simulation process. FEM-simulation software used in this research is SolidWorks 2014 and Abaqus / CAE 6:14. Simulations were performed to analyze the influence of the temperature distribution of the corner cutting that occurs during cutting.

Pore Structure Characterization of Hardened Cement Paste by Multiple Methods

Pore structure characterization of hardened cement paste is important to concrete mechanical and transport properties. Hence, we apply indirect methods (NS, MIP, and NMR) and direct methods (XCT, FIB/SEM, and HIM) to provide a general view of the pore structure of hardened cement paste. The results show that the 3D pore network of hardened cement paste is isolated in microscale yet is largely connected by large capillary pores, small capillary pores, and microcracks in nanoscale. In indirect methods, MIP and NMR have a wide measurement range and permit observing most of the porous volume with an average porosity of 8.4–9.9% of hardened cement paste. In contrast, direct methods have a relatively narrow measurement range and thus lead to a large porosity scattering of 1.8–16.4%. The pore size distribution (PSD) curves by indirect methods show that the pore structure is mainly concentrated in three sections of 1–10 nm, 10–100 nm, and around 10 μm, which correspond to the imaging range of HIM, FIB/SEM, and XCT. However, FIB/SEM implies that the most porous part of hardened cement paste (10–100 nm) is underestimated by MIP due to the “ink-bottle” effect. Another “underestimation” of NMR is because C-S-H gels swell during the wetting, and the swelling separates the capillary pores into smaller ones. The microcracks induced by sample preparation contribute 0.1-0.2% (XCT) and 4.5–8.1% (FIB/SEM) of porosity to the porous volume of cement paste, but they have limited influence on the pore size distribution and pore connectivity.

A novel particle tracking velocimetry method for complex granular flow field**Project supported by the National Natural Science Foundation of China (Grant Nos. 11572201 and 91634202).

Particle tracking velocimetry (PTV) is one of the most commonly applied granular flow velocity measurement methods. However, traditional PTV methods may have issues such as high mismatching rates and a narrow measurement range when measuring granular flows with large bulk density and high-speed contrast. In this study, a novel PTV method is introduced to solve these problems using an optical flow matching algorithm with two further processing steps. The first step involves displacement correction, which is used to solve the mismatching problem in the case of high stacking density. The other step is trajectory splicing, which is used to solve the problem of a measurement range reduction in the case of high-speed contrast The hopper flow experimental results demonstrate superior performance of this proposed method in controlling the number of mismatched particles and better measuring efficiency in comparison with the traditional PTV method.

The scale of Work-Related Affective Feelings (WORAF)

Interest in the field of emotions in the workplace continues to grow. However, a narrow range of measurements exists for the examination of affective states in organizational settings, all of which were developed based on the discrete-emotions approach. The main objective of the current study was to develop and validate a new instrument to assess four work-related (WR) affective feelings (WORAF): WR feelings of happiness, WR feelings of anxiety, WR feelings of anger, and WR feelings of dejection. Three independent samples of Polish employees in different occupations were included in the study (n = 297, n = 3019, n = 284). The results provide significant evidence for the validity of the proposed WORAF scale, although further investigations are needed.

Optical refractometry using lensless holography and autofocusing.

Conventional optical refractometry methods are often limited by a narrow measurement range, complex hardware, or relatively high cost. Here, we present a novel refractometry method to measure the bulk refractive index (RI) of materials (including solids and liquids) using lensless holographic on-chip imaging and autofocusing, which is simple, cost-effective, and has a large RI measurement range. As a proof of concept, two compact prototypes were built to measure the RIs of solid materials and liquids, respectively, and they were tested by measuring the RIs of a ZnSe plate and a microscopy immersion oil. Experimental results show that our devices have an average accuracy of ~3 × 10-4 RI unit (RIU) with an estimated precision of ~3 × 10-3 RIU for solids; and an average accuracy of ~1 × 10-4 RIU with an estimated precision of ~3 × 10-4 RIU for liquids. We believe that this cost-effective and portable RI measurement platform holds promise to be used in laboratory and industrial settings.

Enlarging density measurement range for polymers by horizontal magneto-Archimedes levitation

To overcome the major limitation of magnetic levitation, narrow density measurement range, a novel horizontal magneto-Archimedes levitation method is proposed for enlarging density measurement range of polymers. This method provides a new way to tune the components of the gravitational force relative to the magnetic field, which enhances the effect of magnetic force acting on the polymers. Experiments with different diamagnetic materials, different paramagnetic solutions, different sized polymers and various polymers were carried out to verify the proposed method. Experimental results show that the method enlarges density measurement range from 1.007–1.483 g/cm3 to 1.244–14.914 g/cm3 (depending on the 2.5 M MnCl2 aqueous solution), and it enables density measurements to be performed for high-density polymers (e.g., Teflon and BMC) and other diamagnetic materials (e.g., Brass, barium sulfate and aluminum). In general, the proposed method has wider measurement range, high-accuracy, simplicity-of-use and low-cost, and it has prospects of broad application in characterizing high-density polymers and polymeric composites.

2A2-M05 環境磁場を用いた移動ロボットの軌跡推定と環境地図構築

A SLAM (Simultaneous Localization and Mapping) problem is major in mobile robotics field about past two decades. In order to solve the problem, a camera and a LIDAR (Light Detection and Ranging) are generally used. In contrast, this paper proposes a new solution for the problem using a magnetic sensor. Our method is simple since an observation model in RBPF (Rao-Blackwellized Particle Filter)-SLAM is replaced by that of a magnetic sensor. However, magnetic sensor-based SLAM has a problem that is so narrow measurement range of the sensor. To deal with the problem, we use a heuristic method to determine surround magnetic field. We conducted experiments in actual outdoor environments including loops and verified its accuracy by using a LIDAR. Through the experiments, it was shwon that our method can close loops and build consistent maps; magnetic and geometric.

Standardising the clinical assessment of coronal knee laxity

Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity through accurate measurement of potential variables during routine clinical examination. The hypothesis was that standardisation of a clinical stress test would result in a repeatable range of laxity measurements. Non-invasive infrared tracking technology with kinematic registration of joint centres gave real-time measurement of both coronal and sagittal mechanical tibiofemoral alignment Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity examinations on a single volunteer using a target moment of 18 Nm. Standardised laxity measurements had small standard deviations (within 1. 1 degree) for each clinician and similar mean values between clinicians, with the valgus laxity assessment (mean of 3 degrees) being slightly more consistent than varus (means of 4 degrees or 5 degrees). The manual technique of coronal knee laxity assessment was successfully quantified and standardised, leading to a narrow range of measurements (within the accuracy of the measurement system). Minimising the subjective variables of clinical examination could improve current knowledge of soft tissue knee behaviour.