Measurement Method Research Articles

Measurement of Pt consumption from Pt electrodes during water electrolysis using the quartz crystal microbalance (QCM) method: Effect of the water electrolysis method and the concentration of chloride ions in the aqueous solution

The consumption of the Pt electrocatalyst, which occurs when aqueous solution with neutral pH is electrolyzed with a Pt electrode to produce hydrogen or oxygen, was measured from the change in resonance frequency using the QCM method. First, it was found that the Pt consumption from the electrode during water electrolysis while applying a steady positive potential was very small, but it was almost proportional to the time the current was applied. Second, when electrolysis was performed by polarity reversal electrolysis of the anode and cathode periodically during electrolysis, the amount of Pt consumed increased in proportion to the number of polarity reversal was exchanged. The Pt consumption obtained by the QCM method was in close agreement with the value obtained by EDX method, proving the validity of the measurement method. The QCM measurement method was also proven to be a reliable method of measurement.

Study on Measurement Method of Three-dimensional Position of Unlabeled Microspheres under Bright Background

Abstract: Using computer vision technology to obtain the position and trajectory data of particle probe microspheres from microscope images has significance and value in the molecular field. However, most of the existing microsphere measurement methods are based on transmission, which can only be measured under transparent samples and substrates and are not suitable for the application scenario of living cell measurement. In this paper, a method based on reflectivity imaging is proposed to measure the three-dimensional position of the dark microspheres in the bright field. Based on the outermost ring radius method, the relationship between the inner ring radius of the microsphere spot and the out-of-focus distance was explored to measure the coordinates in the Z direction. Cardiomyocytes were combined with 10um size silica microspheres. Experiments show that in a bright field with a high perturbation environment, it can achieve high precision measurement of dark microspheres and achieve three-dimensional position measurement with an accuracy of 50nm in XY direction and 100nm in Z direction.

Recent Patents on Particle Wettability Measurement and Improvement

Background: As the coal mining industry becomes more mechanized, it leads to a large number of coal dust particles suspended in the air, polluting the surrounding environment, accompanied by an increase in fine-grained low-rank coal particles and a low recovery rate of a large amount of organic matter in the particles, wasting resources. Objective: The study of particle wettability can have an impact on spray dust reduction and particle flotation efficiency. By adjusting the hydrophilicity of coal powder particles, the generation of suspended coal dust can be effectively suppressed. By adding surfactants, the flotation separation efficiency of coal particles can be improved. Method: This article introduces the measurement method of particle wetting properties and methods to improve the wetting properties of particles, providing a reference for studying the wetting properties of particles Results: The measurement of particle wetting properties is more accurate, simple, and convenient. Improving the wetting properties of particles by adding additives has significant implications for later dust reduction and particle flotation. Conclusion: This thesis provides an important basis for studying the wettability of particles, modifying the wettability and hydrophilicity of particles, providing specific guidance for improving the wettability of particles for spray dust reduction and particle flotation, and greatly improving industrial production efficiency.

Surface Strain Measurement for Non-Intrusive Internal Pressure Evaluation of a Cannon

Abstract Recent cutting-edge designs for gun barrels, projectiles, and propellants require testing, such as measuring the internal pressure during firing. However, there are concerns with the current drilling method to mount pressure transducers near the breech and chamber of the gun barrel where pressure is highest. To address this challenge, the team hereby presents an alternative, nonintrusive strain measurement method. This method focuses on determining the feasibility and accuracy of relating tangential strain along the sidewall of a gun barrel to the drastic internal pressure rise created during combustion. A transient structural, numerical model of a 155 mm gun barrel was created using ansys. The pressure was derived using the outline in Interior Ballistics of High Velocity Guns, version 2, and the model was validated using published experimental tangential strain testing data from a gun of the same caliber. The model was then used to demonstrate the ideal location for strain measurement along the sidewall of the chamber. Furthermore, three different pressure ranges were simulated in the model. The behavior of the tangential strain in each case indicates a similar trend to the internal pressure rise and oscillation due to a dominant frequency of the barrel. A method to predict internal pressure from external tangential strain was developed. The internal pressure predicted is within 4% of the pressure applied in the model. In the sensitivity study, the thickness and elastic modulus of the gun barrel were found to be the primary factors affecting tangential strain. Overall, this work helps to understand tangential strain behavior on the sidewall of a large-caliber gun barrel and lays the ground for an accurate prediction of internal pressure from external tangential strain.

Stimulation of the withdrawal reflex in gait training after stroke: A systematic review and meta-analysis.

After a stroke many people experience hemiparesis, resulting in walking difficulties which affects independence, mobility, and participation in activities of daily living. Activating the nociceptive withdrawal reflex (NWR) during gait training aims to support the initiation and facilitation of the swing phase of the paretic leg. The aim of this review is to investigate the orthotic and therapeutic effects of a NWR stimulation intervention to improve gait in patients after a stroke. We searched the databases CENTRAL, DORIS, MEDLINE, and PEDro, trial registers and reference lists. We selected randomized controlled trials using any type of stimulation of the NWR in people after stroke, comparing it to any control intervention, and reporting a change in gait performance assessed by means of any appropriate measurement method. We included three studies in this review, all of which used electrical stimulation to elicit the NWR during walking. The orthotic effect was investigated in one study, and the therapeutic effect in two studies, comparing walking with and without electrical stimulation-triggered NWR. The meta-analysis revealed a borderline statistical significance result for the therapeutic effect. The pooled mean difference between the treatment and control group (random-effects model) for walking speed was 0.13 m/s (95% CI -0.04 to 0.29; I2 = 72%) after treatment and 0.17 m/s (95% CI -0.03 to 0.37; I2 = 62%) at follow-up. Activating the NWR during gait training has not been investigated frequently so far. By using electrical stimulation-elicited NWR, severely affected hemiparetic patients may improve their walking speed.

Point of care ultrasound measurement of paralumbar caudal vena cava diameter and caudal vena cava to aortic ratio in hypovolemic dogs

BackgroundAccurate assessment of intravascular volume is critical for precise fluid prescription. In people, bedside or point of care ultrasound is used to measure the inferior vena cava, with or without paired aortic measurement, to estimate intravascular volume.ObjectiveTo determine if point of care ultrasound measurement of the caudal vena cava (CVC) diameter or the CVC diameter to the abdominal aorta (Ao) diameter (CVC:Ao) at the paralumbar view are associated with changes in intravascular volume, mean arterial pressure (MAP), or cardiac output in normovolemic and hypovolemic dogs.Animals8 purpose-bred dogs.MethodsPressure-targeted hemorrhagic shock was induced in purpose-bred dogs under general anesthesia. Dogs were exsanguinated to a mean arterial pressure of 40 mmHg, or a maximum 60% blood volume lost, then auto-transfused shed blood. At a left paralumbar view, longitudinal plane measurements of the abdominal CVC diameter and aortic diameter were obtained. Measurements were performed at 4 timepoints: baseline under anesthesia (TP1), after hemorrhagic shock was induced (TP2), after ½ of shed blood had been re-transfused (TP3), and post-resuscitation with completed re-transfusion (TP4). Additional variables collected included cardiac output using thermodilution and arterial blood pressure.ResultsCVC:Ao was not significantly different between timepoints and was not associated with changes in CO (p = 0.28) or MAP (p = 0.50). CVC diameter was significantly different between baseline (TP1) and hemorrhagic shock (TP2). CVC diameter was significantly different at TP2 compared to TP1 after controlling for the effect of CO (p = 0.03) and MAP (p = 0.001). Aortic diameter was also significantly different at TP2 (p = 0.002, p = 0.001) and TP3 (p = 0.023, p = 0.017) compared to TP1 after controlling for CO and MAP.Conclusions and clinical importanceObtaining point of care ultrasound images for CVC:Ao measurement was feasible. With a marked decrease in intravascular volume, both CVC and Ao diameter decreased, resulting in an unchanged CVC:Ao. Despite changes in CVC and Ao diameters, these changes were not associated with measured changes in CO, emphasizing that CO is not a direct estimate of intravascular volume and is affected by many compensatory mechanisms. Additional studies are needed to determine the most accurate method for bedside measurement of intravascular volume status.

Measurement Method of Femoral Anteversion During Surgery for Trochanteric Fractures

Measurement Method of Femoral Anteversion During Surgery for Trochanteric Fractures

Large Room-Temperature Electrocaloric Effect in Lead-Free Relaxor Ferroelectric Ceramics with Wide Operation Temperature Range

In order to obtain large room-temperature electrocaloric effect (ECE) and wide operation temperature range simultaneously in lead-free ceramics, we proposed designing a relaxor ferroelectric with a Tm (the temperature at which the maximum dielectric permittivity is achieved) near-room temperature and glass addition. Based on this strategy, we designed and fabricated lead-free 0.76NaNbO3–0.24BaTiO3 (NN-24BT) ceramics with 1wt.% BaO–B2O3–SiO2 glass addition, which showed distinct relaxor ferroelectric characteristics with strongly diffused phase transition and a Tm near-room temperature. Based on a direct measurement method, a large ΔT (adiabatic temperature change) of 1.3 K was obtained at room temperature under a high field of 11.0 kV mm−1. Additionally, large ECE can be maintained (>0.6 K@6.1 kV mm−1) over a broad temperature range from 23 °C to 69 °C. Moreover, the ECE displayed excellent cyclic stability with a variation in ΔT below ±7% within 100 test cycles. The comprehensive ECE performance is significantly better than other lead-free ceramics. Our work provides a general and effective approach to designing lead-free, high-performance ECE ceramics, and the approach possesses the potential to be utilized to improve the ECE performance of other lead-free ferroelectric ceramic systems.

Retraction Note: A full freedom pose measurement method for industrial robot based on reinforcement learning algorithm

Retraction Note: A full freedom pose measurement method for industrial robot based on reinforcement learning algorithm

Investigation of Radiation Exposure of Medical Staff During Lateral Fluoroscopy for Posterior Spinal Fusion Surgery

Background/Objectives: In spinal surgery, it is especially crucial to insert implants in the correct location. Intraoperative fluoroscopy is often necessary to safely perform spinal surgery because of serious complications that can occur if the screw deviates. However, the use of intraoperative fluoroscopy comes at the cost of radiation exposure to the surgeons and operating room staff. Therefore, it is desirable for spinal surgeons to understand the characteristics of radiation in order to minimize patient and medical staff exposure. This study aimed to create an aerial radiation dose distribution map for lateral fluoroscopy, a commonly used technique for posterior spinal fusion. Methods: A human body-equivalent phantom was placed in a prone position on the Jackson Table. The measurement method used was a lateral fluoroscopic evaluation, assuming posterior spinal fusion. Measurements were taken at three levels: 80 (gonadal), 100 (thoracoabdominal), and 150 cm (lens and thyroid). Results: The highest radiation doses were received by primary surgeons. The scrub nurse was the next most exposed. Conclusions: We developed an aerial dose distribution map for lateral fluoroscopy in posterior spinal fusion. Radiation exposure was the highest among primary surgeons.

A Thermopile-Based Colorimetric Temperature Measurement Method for Arbitrary Bandwidth

Colorimetric temperature measurement is an essential technique in radiometric thermometry. Traditional colorimetric methods determine temperature by comparing the ratio of radiative energies within two narrow bands at specific wavelengths, effectively mitigating the effects of the emissivity of the measured object and ambient conditions. However, these methods typically approximate integration using area calculations when calculating radiative energy. This article eliminates this approximation and calculates the radiative energy with accurate integration. Based on the principle of monotonicity, this article demonstrates for the first time that when two narrow-band infrared radiations are selected, as long as their wavelength ranges do not overlap, the ratio of radiative energies within these bands maintains a monotonic relationship with the measured temperature. This allows the temperature to be inferred from the energy ratio. Furthermore, this conclusion is extended to arbitrary widths of bands as long as their wavelength ranges do not overlap. Building on this foundation, a thermopile-based colorimetric temperature measurement method for arbitrary bandwidth is proposed. Simulation experiments validate this method, showing that the energy ratio maintains a monotonic relationship with the measured temperature as long as the infrared radiation wavelength ranges absorbed by the thermopile do not overlap. The simulation results are consistent with the mathematical proof.

Visualization of Aerial Droplet Distribution for Unmanned Aerial Spray Systems Based on Laser Imaging

Unmanned aerial spray systems (UASSs) are a commonly used spraying method for plant protection operations. However, their spraying parameters have complex effects on droplet distribution. The large-scale 3D droplet density distribution measurement method is insufficient, especially since the downwash wind is easily affected by the environment. Therefore, there is a need to develop a technique that can quickly visualize 3D droplet distribution. In this study, a laser imaging method was proposed to quickly scan moving droplets in the air, and a test method that can visualize 3D droplet distribution was constructed by using the traveling mode of the machine perpendicular to the scanning plane. The 3D droplet distribution of targeted and conventional UAVs was tested, and the methods for signal processing, noise reduction, and point cloud rebuilding for laser imaging were developed. Compared with the simulation results, laser imaging showed the pattern of droplet distribution from the two UAV structures well. The results showed that the laser imaging based method for detecting 3D droplet distribution is feasible, fast, and environmentally friendly.

Mammographic Breast Density at Breast Cancer Diagnosis and Breast Cancer-Specific Survival

Background: Breast density impacts upon breast cancer risk and recurrence, but its influence on breast cancer-specific survival is unclear. This study examines the influence of mammographic breast density (MBD) at diagnosis on breast cancer-specific survival. Methods: The data of 224 patients diagnosed with breast cancer were analyzed. Two area-based MBD measurement tools—AutoDensity and LIBRA—were used to measure MBD via a mammogram of the contralateral breast acquired at the time of diagnosis. These patients were split into two groups based on their percent breast density (PBD): high (PBD ≥ 20%) versus low (PBD < 20%). Breast cancer-specific survival in each of these PBD groups was assessed at a median follow-up of 34 months using Kaplan–Meier analysis and the Cox proportional hazards model. Results: The proportion of women with low PBD who died from breast cancer was significantly higher than that seen with high PBD (p = 0.01). The 5-year breast cancer-specific survival was poorer among women with low PBD than those with high PBD (0.348; 95% CI: 0.13–0.94) vs. 0.87; 95% CI: (0.8–0.96); p < 0.001)]. Women with higher breast density demonstrated longer survival regardless of the method of PBD measurement: LIBRA [log-rank test (Mantel–Cox): 9.4; p = 0.002)]; AutoDensity [log-rank test (Mantel–Cox) 7.6; p = 0.006]. Multivariate analysis also demonstrated that there was a higher risk of breast cancer-related deaths in women with low PBD (adjusted HR: 5.167; 95% CI: 1.974–13.521; p = 0.001). Conclusion: Women with <20% breast density at breast cancer diagnosis demonstrate poor survival regarding the disease. The impact of breast density on survival is not influenced by the method of measurement.

Methods in fluctuation (noise) spectroscopy and continuous analysis for high-throughput measurements

Abstract Fluctuation (noise) spectroscopy is widely used to investigate the low-frequency dynamics of charge carriers in condensed-matter systems, aiming to (i) improve the performance of micro- and nanoscale electronic devices and sensors, and (ii) use ‘noise as a signal’ in order to fundamentally investigate the microscopic motion and transitions of charge carriers coupled to the low-lying excitations in solids. Here, we focus on measurements of the ubiquitous 1 / f -type fluctuations, often composed by a superposition of (independent or correlated) two-level systems each giving rise to a Lorentzian spectrum, denoted random telegraph noise in the time domain. We briefly review the basic concepts of noise and fluctuations and give a comprehensive overview of state-of-the-art measuring techniques, using both commercially available signal analyzers and custom software in order to perform the spectral analysis of the recorded time signals, and critically evaluate their advantages and drawbacks. We describe how to use fast data acquisition devices in a cross-correlation setup providing additional quantitative information on the magnitude of uncorrelated instrument noise, and demonstrate the mathematical intricacies of extracting the noise spectra. We introduce a new method for high-throughput measurements by automated spectral analysis based on the concept of Continuous Analysis. We demonstrate the potential of this technique, working towards a FAIR data workflow, by measurements of magnetic flux noise within the hysteresis loop of ferromagnetic nanostructures.

Highly accurate absolute optical transfer delay measurement over a long distance assisted by the pulse time signal

In this paper, an absolute optical transfer delay measurement method based on pulse time signal, pseudo-random code phase, and microwave phase is proposed. By employing two-stage integer ambiguity resolution, not only can a measurement range of several hundred kilometers be achieved, but sub-picosecond level measurement accuracy can also be attained. A test system was built in the laboratory and experimentally verified on a fiber optic link. The experimental results verify an accuracy of ±0.1 ps in measuring an ultrahigh-accuracy optical delay line. In addition, long fiber is also tested, which proves that a measurement range of at least 100 km can be achieved. The refresh rate of the measurement results can reach 100 ms each time.

The effects of pregnancy on oral health, salivary ph and flow rate

BackgroundThe frequent occurrence of dental caries and periodontal diseases in women during pregnancy may be due to many factors, such as salivary variables. The aim of this study was to evaluate the effects of pregnancy on salivary pH, flow rate, the DMFT index, and CPI sores.MethodsA total of 198 volunteers (pregnant in different trimesters and non- pregnant) were included for the present observational cross-sectional study. Data about sociodemographic characteristics and dental and systemic health conditions were recorded. Unstimulated saliva samples were collected for 5 min via the spitting method. The pH of the saliva was measured by a portable pH meter. The salivary flow rate was determined by the weight measurement method. The DMFT index and CPI were determined. The statistical evaluation was performed using Robust ve Poisson Regression analyses (p < 0.05).ResultsIt was determined that there was a gradually significant decrease in the Ph value from the first trimester to the third trimester during pregnancy, which was lower than the control group. (p < 0.001) The flow rate of pregnants in their third trimester was lower than that of first trimester (p = 0.017). The CPI scores of pregnant women were significantly greater than that of non-pregnants (p = 0.042), while the DMFTs were similar among all groups.ConclusionOur findings indicate that pregnancy leads to a notable reduction in unstimulated salivary pH and flow rate, which also has a detrimental impact on periodontal health.Trial registrationClinical Trials-ID: NCT06343337; Registration Date: 04.01.2024.

Evaluation and fusion of multi-source sea ice thickness products with limited in-situ observations

Sea ice thickness (SIT) is a critical and sensitive parameter in the climate system, with its dynamic changes profoundly influencing global climate models, navigational routes, and the potential for Arctic resource development. Given the widespread application of current satellite remote sensing technology in monitoring SIT, significant uncertainties remain. This study first underscores the importance of in-situ observations as a direct measurement method for SIT. However, the limitations of in-situ data in terms of acquisition cost, spatiotemporal coverage continuity, and distribution uniformity significantly hinder the effective evaluation of multi-source SIT products. To address this, the study innovatively introduces the Triple Collocation (TC) method, which effectively mitigates the impact of errors from individual data sources on the overall evaluation results through a mutual validation mechanism among multiple satellite data sources. This allows for a scientific assessment of multi-source SIT products even in the context of scarce in-situ observations. The findings indicate that the TC method not only successfully resolves the challenges of multi-source data evaluation but also facilitates data integration among these products, significantly enhancing the overall accuracy and spatiotemporal consistency of SIT data.

High-precision dynamic axial clearance measurement method based on an all-fiber heterodyne microwave-AMCW with an all-phase tracking algorithm

Rotor-stator axial clearance is critical to the safety and efficiency of major rotating machinery. However, factors such as high-speed rotation, narrow space, high temperature, and vibration present significant challenges for high-precision dynamic measurement of axial clearance. This paper proposes an axial clearance measurement method based on an all-fiber heterodyne microwave amplitude-modulated continuous wave (microwave-AMCW) system combined with an all-phase tracking algorithm, characterized by high precision, wide bandwidth, and a large measurement range. To mitigate environmental influences, a heterodyne all-fiber microwave-AMCW optical path structure is developed, and a compact dual-core fiber sensor probe is designed. The all-phase tracking algorithm is introduced to enhance dynamic precision and expand bandwidth. Additionally, what we believe to be a novel bandwidth test method based on time division multiplexing is proposed to evaluate the system's wide-bandwidth performance. The proposed system's performance is validated through simulations and experiments. The results demonstrate that the system exhibits excellent resistance to environmental interference, with a measurement range up to 24.5 mm and a static precision better than 4.5µm. Dynamic experiments further confirm the algorithm's effectiveness, achieving a precision better than 5.3µm at 100kHz bandwidth. Compared to other clearance measurement algorithms including the Hilbert transform and FFT, the proposed method reduces dynamic error by over 74%.

Phase-based video vibration measurement and fault feature extraction method for compound faults of rolling bearings

Vibration characterization of rotating machinery is crucial for determining rotational and failure frequencies. Traditional contact measurement methods have limitations, while high-speed cameras offer a non-contact alternative for measuring target vibrations, spatial phase-based techniques have recently been widely used in detecting subtle vibrations and show good robustness to imaging noise. In this paper, a vision-based vibration extraction method for rotating machinery is proposed, aiming at extracting minor vibrations of bearings from them and further analyzing their fault frequencies. To address the challenge of separating a single fault frequency from the extracted compound faulty vibration signals, kurtosis is employed to analyze the inverse convolution period of multiple periodic components, and the MOMEDA filter length is optimized using the golden section algorithm. MOMEDA is then used to enhance each periodic pulse separately, and fault frequency is obtained through envelope spectrum demodulation. In the experimental part, a phase-based method is used to extract minor vibration displacements from rotor vibration video, which is subsequently compared with eddy current sensors in both time and frequency domains to verify the accuracy of the proposed method in extracting vibration displacements based on vision. Finally, vibration signals are extracted from the bearing compound fault video, and the single fault frequency characteristics of the bearing are successfully separated using the adaptive MOMEDA method, which provides an efficient and reliable method in the field of rotating machinery fault diagnosis.

Precise and accurate speed measurements in rapidly flowing dense suspensions

We introduce a method for precise and accurate measurements of particle speeds in dense suspensions flowing at high rates and demonstrate the utility of the approach for revealing complex flow fluctuations during shearing in a setup that combines imaging with a confocal microscope and shearing with a rheometer. We scan the focal point in one dimension, aligned with direction of flow, producing absolute measurements of speed that are independent of suspension structure and particle shape. We compare this flow-direction line scanning approach with a complementary method we introduced previously, measuring speed using line scanning in the vorticity direction. By comparing results in various flow conditions, including shear-thinning and thickening regimes, we demonstrate the efficacy of our new approach. We find that both approaches exhibit qualitatively similar flow profiles, but a comparative analysis reveals a 15%–25% overestimation in speed measurement using vorticity line scanning, with discrepancies generated by anisotropic suspension microstructure under flow. Moreover, in the thickening regime where complex flow fields are present, both approaches capture local speed fluctuations. However, line scanning in the flow direction reveals and precisely captures stagnation and backflows, a capability not achievable with vorticity line scanning. The approach introduced here not only provides a refined technique for speed measurement in fast-flowing suspensions but also emphasizes the significance of accurate measurement techniques in advancing our understanding of flow behavior in dense suspensions, particularly in contexts where strong non-affine flows are prevalent.